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07070100000000000081A40000000000000000000000016217DF4F00000063000000000000000000000000000000000000002000000000gasket-driver-1.0.18/.gitignoredebian/.debhelper
debian/*debhelper*
debian/files
debian/gasket-dkms.substvars
debian/gasket-dkms/
07070100000001000081A40000000000000000000000016217DF4F0000044D000000000000000000000000000000000000002500000000gasket-driver-1.0.18/CONTRIBUTING.md# How to Contribute

We'd love to accept your patches and contributions to this project. There are
just a few small guidelines you need to follow.

## Contributor License Agreement

Contributions to this project must be accompanied by a Contributor License
Agreement. You (or your employer) retain the copyright to your contribution;
this simply gives us permission to use and redistribute your contributions as
part of the project. Head over to <https://cla.developers.google.com/> to see
your current agreements on file or to sign a new one.

You generally only need to submit a CLA once, so if you've already submitted one
(even if it was for a different project), you probably don't need to do it
again.

## Code reviews

All submissions, including submissions by project members, require review. We
use GitHub pull requests for this purpose. Consult
[GitHub Help](https://help.github.com/articles/about-pull-requests/) for more
information on using pull requests.

## Community Guidelines

This project follows [Google's Open Source Community
Guidelines](https://opensource.google.com/conduct/).
07070100000002000081A40000000000000000000000016217DF4F000046AC000000000000000000000000000000000000001D00000000gasket-driver-1.0.18/LICENSE                    GNU GENERAL PUBLIC LICENSE
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07070100000003000081A40000000000000000000000016217DF4F00000265000000000000000000000000000000000000001F00000000gasket-driver-1.0.18/README.md# Coral Gasket Driver

The Coral Gasket Driver allows usage of the [Coral EdgeTPU](https://coral.ai/) on Linux systems. The driver contains two modules:

* Gasket: Gasket (Google ASIC Software, Kernel Extensions, and Tools) is a top level driver for lightweight communication with Google ASICs.
* Apex: Apex refers to the [EdgeTPU v1](https://coral.ai/technology)

This repo contains both the source for direct integration into a kernel tree as well as the necessary files to generate a Debian DKMS package.

## Building Debian DKMS pacakge

From the top level directory, execute:

```
debuild -us -uc -tc -b
```
07070100000004000041ED0000000000000000000000026217DF4F00000000000000000000000000000000000000000000001C00000000gasket-driver-1.0.18/debian07070100000005000081A40000000000000000000000016217DF4F00000BCD000000000000000000000000000000000000002600000000gasket-driver-1.0.18/debian/changeloggasket-dkms (1.0-18) unstable; urgency=low

* Import DMA_BUF symbol namespace for kernels >= 5.16.

-- Coral <coral-support@google.com>  Thu, 24 Feb 2022 11:30:13 -0700

gasket-dkms (1.0-17) unstable; urgency=low

* Include a udev rule for access to the Apex group.

-- Coral <coral-support@google.com>  Thu, 01 Jul 2021 14:39:41 -0700

gasket-dkms (1.0-16) unstable; urgency=low

* Bump module versions for Gasket and Apex

-- Coral <coral-support@google.com>  Fri, 11 Jun 2021 07:53:18 -0700

gasket-dkms (1.0-15) unstable; urgency=low

* Switch include of rwlock to spinlock (rwlock.h isn't intended to be
    directly included).
  * Update Debian files for a clean lintian run.

-- Coral <coral-support@google.com>  Fri, 21 May 2021 09:40:36 -0700

gasket-dkms (1.0-14) unstable; urgency=low

* Unregister MSI-x interrupts in suspend.

-- Coral <coral-support@google.com>  Mon, 12 Oct 2020 15:26:54 -0700

gasket-dkms (1.0-13) unstable; urgency=low

* Fix compilation for 5.6+ kernels.

-- Coral <coral-support@google.com>  Fri, 07 Aug 2020 15:06:07 -0700

gasket-dkms (1.0-12) unstable; urgency=low

* Fix compilation for 5.1+ kernels.

-- Coral <coral-support@google.com>  Wed, 08 Jul 2020 12:11:43 -0700

gasket-dkms (1.0-11) unstable; urgency=low

* Fix thermal monitoring for suspend/resume.
  * Don't require all pages to be writable.
  * Support mapping of dma-bufs.

-- Coral <coral-support@google.com>  Mon, 08 Jun 2020 16:10:59 -0700

gasket-dkms (1.0-10) unstable; urgency=low

* Fix linux-headers dependency.

-- Coral <coral-support@google.com>  Thu, 02 Jan 2020 14:19:30 -0800

gasket-dkms (1.0-9) unstable; urgency=low

* Increase gasket version.

-- Coral <coral-support@google.com>  Wed, 13 Nov 2019 18:03:26 -0800

gasket-dkms (1.0-8) unstable; urgency=low

* Add unique chip id sysfs node.

-- Coral <coral-support@google.com>  Fri, 18 Oct 2019 12:38:57 -0700

gasket-dkms (1.0-7) unstable; urgency=low

* Update to latest version.
  * Add dma_bit_mask gasket module parameter.

-- Coral <coral-support@google.com>  Mon, 23 Sep 2019 15:06:40 -0700

gasket-dkms (1.0-6) unstable; urgency=low

* Enable DFS and thermal shutdown by default.
  * Add DFS support.

-- Coral <coral-support@google.com>  Tue, 11 Jun 2019 12:04:55 -0700

gasket-dkms (1.0-5) unstable; urgency=low

* Add missing dkms file.

-- Coral <coral-support@google.com>  Thu, 6 Jun 2019 20:46:18 -0700

gasket-dkms (1.0-4) unstable; urgency=low

* Add thermal sysfs nodes.
  * Release taken eventfd contexts

-- Coral <coral-support@google.com>  Wed, 15 May 2019 21:09:24 -0700

gasket-dkms (1.0-3) unstable; urgency=low

* Fix pci remove/rescan

-- Coral <coral-support@google.com>  Fri, 25 Mar 2019 17:54:48 -0700

gasket-dkms (1.0-2) unstable; urgency=low

* Pull in fixes

-- Coral <coral-support@google.com>  Fri, 22 Mar 2019 15:14:39 -0700

gasket-dkms (1.0-1) unstable; urgency=low

* Initial release.

-- Coral <coral-support@google.com>  Wed, 04 Mar 2019 16:12:55 +0000
07070100000006000081A40000000000000000000000016217DF4F00000003000000000000000000000000000000000000002300000000gasket-driver-1.0.18/debian/compat10
07070100000007000081A40000000000000000000000016217DF4F0000020A000000000000000000000000000000000000002400000000gasket-driver-1.0.18/debian/controlSource: gasket-dkms
Maintainer: Coral <coral-support@google.com>
Build-Depends: debhelper (>= 9), dkms
Homepage: https://coral.withgoogle.com/

Package: gasket-dkms
Architecture: all
Priority: optional
Section: kernel
Depends: dkms (>= 1.95), linux-headers-686-pae | linux-headers-amd64 | linux-headers-generic | linux-headers, ${misc:Depends}
Description: DKMS source for the gasket driver
 Gasket (Google ASIC Software, Kernel Extensions, and Tools) provides 
 support for Google ASICs, specificially the Coral EdgeTPU.
07070100000008000081A40000000000000000000000016217DF4F0000042C000000000000000000000000000000000000002600000000gasket-driver-1.0.18/debian/copyrightFormat: https://www.debian.org/doc/packaging-manuals/copyright-format/1.0/
Upstream-Name: Gasket DKMS
Source: https://github.com/google/gasket-driver

Files: *
Copyright: 2021 Google LLC <coral-support@google.com>
License: GPL-2+
 This program is free software; you can redistribute it
 and/or modify it under the terms of the GNU General Public
 License as published by the Free Software Foundation; either
 version 2 of the License, or (at your option) any later
 version.
 .
 This program is distributed in the hope that it will be
 useful, but WITHOUT ANY WARRANTY; without even the implied
 warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR
 PURPOSE.  See the GNU General Public License for more
 details.
 .
 You should have received a copy of the GNU General Public
 License along with this package; if not, write to the Free
 Software Foundation, Inc., 51 Franklin St, Fifth Floor,
 Boston, MA  02110-1301 USA
 .
 On Debian systems, the full text of the GNU General Public
 License version 2 can be found in the file
 `/usr/share/common-licenses/GPL-2'.
07070100000009000081A40000000000000000000000016217DF4F000000E9000000000000000000000000000000000000002D00000000gasket-driver-1.0.18/debian/gasket-dkms.dkmsPACKAGE_NAME="gasket"
PACKAGE_VERSION="#MODULE_VERSION#"
BUILT_MODULE_NAME[0]="gasket"
BUILT_MODULE_NAME[1]="apex"
DEST_MODULE_LOCATION[0]="/updates/dkms"
DEST_MODULE_LOCATION[1]="/updates/dkms"
AUTOINSTALL="YES"
REMAKE_INITRD="YES"
0707010000000A000081A40000000000000000000000016217DF4F0000002D000000000000000000000000000000000000002D00000000gasket-driver-1.0.18/debian/gasket-dkms.udevSUBSYSTEM=="apex", MODE="0660", GROUP="apex"
0707010000000B000081ED0000000000000000000000016217DF4F00000153000000000000000000000000000000000000002200000000gasket-driver-1.0.18/debian/rules#!/usr/bin/make -f

include /usr/share/dpkg/pkg-info.mk

%:
	dh $@ --with dkms

override_dh_install:
	dh_install src/* usr/src/gasket-$(DEB_VERSION_UPSTREAM)/

override_dh_dkms:
	dh_dkms -V $(DEB_VERSION_UPSTREAM)

override_dh_auto_configure:
override_dh_auto_build:
override_dh_auto_test:
override_dh_auto_install:
override_dh_auto_clean:0707010000000C000041ED0000000000000000000000026217DF4F00000000000000000000000000000000000000000000001900000000gasket-driver-1.0.18/src0707010000000D000081A40000000000000000000000016217DF4F000002CB000000000000000000000000000000000000002100000000gasket-driver-1.0.18/src/Kconfigmenu "Gasket devices"

config STAGING_GASKET_FRAMEWORK
	tristate "Gasket framework"
	depends on PCI && (X86_64 || ARM64)
	help
	  This framework supports Gasket-compatible devices, such as Apex.
	  It is required for any of the following module(s).

To compile this driver as a module, choose M here.  The module
	  will be called "gasket".

config STAGING_APEX_DRIVER
	tristate "Apex Driver"
	depends on STAGING_GASKET_FRAMEWORK
	help
	  This driver supports the Apex Edge TPU device.  See
	  https://cloud.google.com/edge-tpu/ for more information.
	  Say Y if you want to include this driver in the kernel.

To compile this driver as a module, choose M here.  The module
	  will be called "apex".

endmenu
0707010000000E000081A40000000000000000000000016217DF4F00000180000000000000000000000000000000000000002200000000gasket-driver-1.0.18/src/Makefile#
#  Makefile for Gasket framework and dependent drivers.
#

obj-m += gasket.o
obj-m += apex.o

gasket-objs	:= gasket_core.o gasket_ioctl.o gasket_interrupt.o gasket_page_table.o gasket_sysfs.o
apex-objs	:= apex_driver.o

KVERSION := $(shell uname -r)

all:
	$(MAKE) -C /lib/modules/$(KVERSION)/build M=$(PWD) modules

clean:
	$(MAKE) -C /lib/modules/$(KVERSION)/build M=$(PWD) clean
0707010000000F000081A40000000000000000000000016217DF4F00000214000000000000000000000000000000000000001E00000000gasket-driver-1.0.18/src/TODOThis is a list of things that need to be done to get this driver out of the
staging directory.
- Document sysfs files with Documentation/ABI/ entries.
- Use misc interface instead of major number for driver version description.
- Add descriptions of module_param's
- apex_get_status() should actually check status.
- "drivers" should never be dealing with "raw" sysfs calls or mess around with
  kobjects at all. The driver core should handle all of this for you
  automaically. There should not be a need for raw attribute macros.
07070100000010000081A40000000000000000000000016217DF4F0000047C000000000000000000000000000000000000002000000000gasket-driver-1.0.18/src/apex.h/* SPDX-License-Identifier: GPL-2.0 */
/*
 * Apex kernel-userspace interface definitions.
 *
 * Copyright (C) 2018 Google, Inc.
 */
#ifndef __APEX_H__
#define __APEX_H__

#include <linux/ioctl.h>

/* Clock Gating ioctl. */
struct apex_gate_clock_ioctl {
	/* Enter or leave clock gated state. */
	u64 enable;

/* If set, enter clock gating state, regardless of custom block's
	 * internal idle state
	 */
	u64 force_idle;
};

/* Performance expectation ioctl. */
enum apex_performance_expectation {
        APEX_PERFORMANCE_LOW = 0,
        APEX_PERFORMANCE_MED = 1,
        APEX_PERFORMANCE_HIGH = 2,
        APEX_PERFORMANCE_MAX = 3,
};

struct apex_performance_expectation_ioctl {
        /* Expected performance from apex. */
        uint32_t performance;
};

/* Base number for all Apex-common IOCTLs */
#define APEX_IOCTL_BASE 0x7F

/* Enable/Disable clock gating. */
#define APEX_IOCTL_GATE_CLOCK                                                  \
	_IOW(APEX_IOCTL_BASE, 0, struct apex_gate_clock_ioctl)

#define APEX_IOCTL_PERFORMANCE_EXPECTATION _IOW(APEX_IOCTL_BASE, 1, struct apex_performance_expectation_ioctl)

#endif /* __APEX_H__ */
07070100000011000081A40000000000000000000000016217DF4F00008CE9000000000000000000000000000000000000002700000000gasket-driver-1.0.18/src/apex_driver.c// SPDX-License-Identifier: GPL-2.0
/*
 * Driver for the Apex chip.
 *
 * Copyright (C) 2018 Google, Inc.
 */

#include <linux/atomic.h>
#include <linux/compiler.h>
#include <linux/delay.h>
#include <linux/device.h>
#include <linux/fs.h>
#include <linux/init.h>
#include <linux/mm.h>
#include <linux/module.h>
#include <linux/moduleparam.h>
#include <linux/pci.h>
#include <linux/printk.h>
#include <linux/sched.h>
#include <linux/uaccess.h>
#include <linux/workqueue.h>

#include "apex.h"

#include "gasket_core.h"
#include "gasket_interrupt.h"
#include "gasket_page_table.h"
#include "gasket_sysfs.h"

/* Constants */
#define APEX_DEVICE_NAME "Apex"
#define APEX_DRIVER_VERSION "1.2"

/* CSRs are in BAR 2. */
#define APEX_BAR_INDEX 2

#define APEX_PCI_VENDOR_ID 0x1ac1
#define APEX_PCI_DEVICE_ID 0x089a

/* Bar Offsets. */
#define APEX_BAR_OFFSET 0
#define APEX_CM_OFFSET 0x1000000

/* The sizes of each Apex BAR 2. */
#define APEX_BAR_BYTES 0x100000
#define APEX_CH_MEM_BYTES (PAGE_SIZE * MAX_NUM_COHERENT_PAGES)

/* The number of user-mappable memory ranges in BAR2 of a Apex chip. */
#define NUM_REGIONS 3

/* The number of nodes in a Apex chip. */
#define NUM_NODES 1

/*
 * The total number of entries in the page table. Should match the value read
 * from the register APEX_BAR2_REG_KERNEL_HIB_PAGE_TABLE_SIZE.
 */
#define APEX_PAGE_TABLE_TOTAL_ENTRIES 8192

#define APEX_EXTENDED_SHIFT 63 /* Extended address bit position. */

/* Check reset 120 times */
#define APEX_RESET_RETRY 120
/* Wait 100 ms between checks. Total 12 sec wait maximum. */
#define APEX_RESET_DELAY 100

/* Interval between temperature polls, 0 disables polling */
#define DEFAULT_APEX_TEMP_POLL_INTERVAL 5000

/* apex device private data */
struct apex_dev {
	struct gasket_dev *gasket_dev_ptr;
	struct delayed_work check_temperature_work;
	u32 adc_trip_points[3];
	atomic_t temp_poll_interval;
	u32 hw_temp_warn1_adc;
	u32 hw_temp_warn2_adc;
	bool hw_temp_warn1_en;
	bool hw_temp_warn2_en;
};

/* Enumeration of the supported sysfs entries. */
enum sysfs_attribute_type {
	ATTR_KERNEL_HIB_PAGE_TABLE_SIZE,
	ATTR_KERNEL_HIB_SIMPLE_PAGE_TABLE_SIZE,
	ATTR_KERNEL_HIB_NUM_ACTIVE_PAGES,
	ATTR_TEMP,
	ATTR_TEMP_WARN1,
	ATTR_TEMP_WARN1_EN,
	ATTR_TEMP_WARN2,
	ATTR_TEMP_WARN2_EN,
	ATTR_TEMP_TRIP0,
	ATTR_TEMP_TRIP1,
	ATTR_TEMP_TRIP2,
	ATTR_TEMP_POLL_INTERVAL,
	ATTR_UNIQUE_ID,
};

/*
 * Register offsets into BAR2 memory.
 * Only values necessary for driver implementation are defined.
 */
enum apex_bar2_regs {
	APEX_BAR2_REG_SCU_BASE = 0x1A300,
	APEX_BAR2_REG_KERNEL_HIB_PAGE_TABLE_SIZE = 0x46000,
	APEX_BAR2_REG_KERNEL_HIB_EXTENDED_TABLE = 0x46008,
	APEX_BAR2_REG_KERNEL_HIB_TRANSLATION_ENABLE = 0x46010,
	APEX_BAR2_REG_KERNEL_HIB_INSTR_QUEUE_INTVECCTL = 0x46018,
	APEX_BAR2_REG_KERNEL_HIB_INPUT_ACTV_QUEUE_INTVECCTL = 0x46020,
	APEX_BAR2_REG_KERNEL_HIB_PARAM_QUEUE_INTVECCTL = 0x46028,
	APEX_BAR2_REG_KERNEL_HIB_OUTPUT_ACTV_QUEUE_INTVECCTL = 0x46030,
	APEX_BAR2_REG_KERNEL_HIB_SC_HOST_INTVECCTL = 0x46038,
	APEX_BAR2_REG_KERNEL_HIB_TOP_LEVEL_INTVECCTL = 0x46040,
	APEX_BAR2_REG_KERNEL_HIB_FATAL_ERR_INTVECCTL = 0x46048,
	APEX_BAR2_REG_KERNEL_HIB_DMA_PAUSE = 0x46050,
	APEX_BAR2_REG_KERNEL_HIB_DMA_PAUSE_MASK = 0x46058,
	APEX_BAR2_REG_KERNEL_HIB_STATUS_BLOCK_DELAY = 0x46060,
	APEX_BAR2_REG_KERNEL_HIB_MSIX_PENDING_BIT_ARRAY0 = 0x46068,
	APEX_BAR2_REG_KERNEL_HIB_MSIX_PENDING_BIT_ARRAY1 = 0x46070,
	APEX_BAR2_REG_KERNEL_HIB_PAGE_TABLE_INIT = 0x46078,
	APEX_BAR2_REG_KERNEL_HIB_MSIX_TABLE_INIT = 0x46080,
	APEX_BAR2_REG_KERNEL_WIRE_INT_PENDING_BIT_ARRAY = 0x48778,
	APEX_BAR2_REG_KERNEL_WIRE_INT_MASK_ARRAY = 0x48780,
	APEX_BAR2_REG_USER_HIB_DMA_PAUSE = 0x486D8,
	APEX_BAR2_REG_USER_HIB_DMA_PAUSED = 0x486E0,
	APEX_BAR2_REG_IDLEGENERATOR_IDLEGEN_IDLEREGISTER = 0x4A000,
	APEX_BAR2_REG_KERNEL_HIB_PAGE_TABLE = 0x50000,
	APEX_BAR2_REG_OMC0_D0 = 0x01a0d0,
	APEX_BAR2_REG_OMC0_D4 = 0x01a0d4,
	APEX_BAR2_REG_OMC0_D8 = 0x01a0d8,
	APEX_BAR2_REG_OMC0_DC = 0x01a0dc,
	APEX_BAR2_REG_EFUSE_DC = 0x01a2dc,
	APEX_BAR2_REG_EFUSE_E0 = 0x01a2e0,
	APEX_BAR2_REG_EFUSE_E4 = 0x01a2e4,
	APEX_BAR2_REG_EFUSE_E8 = 0x01a2e8,

/* Error registers - Used mostly for debug */
	APEX_BAR2_REG_USER_HIB_ERROR_STATUS = 0x86f0,
	APEX_BAR2_REG_SCALAR_CORE_ERROR_STATUS = 0x41a0,
};

/* Addresses for packed registers. */
#define APEX_BAR2_REG_AXI_QUIESCE (APEX_BAR2_REG_SCU_BASE + 0x2C)
#define APEX_BAR2_REG_GCB_CLOCK_GATE (APEX_BAR2_REG_SCU_BASE + 0x14)
#define APEX_BAR2_REG_SCU_0 (APEX_BAR2_REG_SCU_BASE + 0xc)
#define APEX_BAR2_REG_SCU_1 (APEX_BAR2_REG_SCU_BASE + 0x10)
#define APEX_BAR2_REG_SCU_2 (APEX_BAR2_REG_SCU_BASE + 0x14)
#define APEX_BAR2_REG_SCU_3 (APEX_BAR2_REG_SCU_BASE + 0x18)
#define APEX_BAR2_REG_SCU_4 (APEX_BAR2_REG_SCU_BASE + 0x1c)
#define APEX_BAR2_REG_SCU_5 (APEX_BAR2_REG_SCU_BASE + 0x20)

#define SCU3_RG_PWR_STATE_OVR_BIT_OFFSET 26
#define SCU3_RG_PWR_STATE_OVR_MASK_WIDTH 2
#define SCU3_CUR_RST_GCB_BIT_MASK 0x10
#define SCU2_RG_RST_GCB_BIT_MASK 0xc

/* Configuration for page table. */
static struct gasket_page_table_config apex_page_table_configs[NUM_NODES] = {
	{
		.id = 0,
		.mode = GASKET_PAGE_TABLE_MODE_NORMAL,
		.total_entries = APEX_PAGE_TABLE_TOTAL_ENTRIES,
		.base_reg = APEX_BAR2_REG_KERNEL_HIB_PAGE_TABLE,
		.extended_reg = APEX_BAR2_REG_KERNEL_HIB_EXTENDED_TABLE,
		.extended_bit = APEX_EXTENDED_SHIFT,
	},
};

/* The regions in the BAR2 space that can be mapped into user space. */
static const struct gasket_mappable_region mappable_regions[NUM_REGIONS] = {
	{ 0x40000, 0x1000 },
	{ 0x44000, 0x1000 },
	{ 0x48000, 0x1000 },
};

/* Gasket device interrupts enums must be dense (i.e., no empty slots). */
enum apex_interrupt {
	APEX_INTERRUPT_INSTR_QUEUE = 0,
	APEX_INTERRUPT_INPUT_ACTV_QUEUE = 1,
	APEX_INTERRUPT_PARAM_QUEUE = 2,
	APEX_INTERRUPT_OUTPUT_ACTV_QUEUE = 3,
	APEX_INTERRUPT_SC_HOST_0 = 4,
	APEX_INTERRUPT_SC_HOST_1 = 5,
	APEX_INTERRUPT_SC_HOST_2 = 6,
	APEX_INTERRUPT_SC_HOST_3 = 7,
	APEX_INTERRUPT_TOP_LEVEL_0 = 8,
	APEX_INTERRUPT_TOP_LEVEL_1 = 9,
	APEX_INTERRUPT_TOP_LEVEL_2 = 10,
	APEX_INTERRUPT_TOP_LEVEL_3 = 11,
	APEX_INTERRUPT_FATAL_ERR = 12,
	APEX_INTERRUPT_COUNT = 13,
};

/* Interrupt descriptors for Apex */
static struct gasket_interrupt_desc apex_interrupts[] = {
	{
		APEX_INTERRUPT_INSTR_QUEUE,
		APEX_BAR2_REG_KERNEL_HIB_INSTR_QUEUE_INTVECCTL,
		UNPACKED,
	},
	{
		APEX_INTERRUPT_INPUT_ACTV_QUEUE,
		APEX_BAR2_REG_KERNEL_HIB_INPUT_ACTV_QUEUE_INTVECCTL,
		UNPACKED
	},
	{
		APEX_INTERRUPT_PARAM_QUEUE,
		APEX_BAR2_REG_KERNEL_HIB_PARAM_QUEUE_INTVECCTL,
		UNPACKED
	},
	{
		APEX_INTERRUPT_OUTPUT_ACTV_QUEUE,
		APEX_BAR2_REG_KERNEL_HIB_OUTPUT_ACTV_QUEUE_INTVECCTL,
		UNPACKED
	},
	{
		APEX_INTERRUPT_SC_HOST_0,
		APEX_BAR2_REG_KERNEL_HIB_SC_HOST_INTVECCTL,
		PACK_0
	},
	{
		APEX_INTERRUPT_SC_HOST_1,
		APEX_BAR2_REG_KERNEL_HIB_SC_HOST_INTVECCTL,
		PACK_1
	},
	{
		APEX_INTERRUPT_SC_HOST_2,
		APEX_BAR2_REG_KERNEL_HIB_SC_HOST_INTVECCTL,
		PACK_2
	},
	{
		APEX_INTERRUPT_SC_HOST_3,
		APEX_BAR2_REG_KERNEL_HIB_SC_HOST_INTVECCTL,
		PACK_3
	},
	{
		APEX_INTERRUPT_TOP_LEVEL_0,
		APEX_BAR2_REG_KERNEL_HIB_TOP_LEVEL_INTVECCTL,
		PACK_0
	},
	{
		APEX_INTERRUPT_TOP_LEVEL_1,
		APEX_BAR2_REG_KERNEL_HIB_TOP_LEVEL_INTVECCTL,
		PACK_1
	},
	{
		APEX_INTERRUPT_TOP_LEVEL_2,
		APEX_BAR2_REG_KERNEL_HIB_TOP_LEVEL_INTVECCTL,
		PACK_2
	},
	{
		APEX_INTERRUPT_TOP_LEVEL_3,
		APEX_BAR2_REG_KERNEL_HIB_TOP_LEVEL_INTVECCTL,
		PACK_3
	},
	{
		APEX_INTERRUPT_FATAL_ERR,
		APEX_BAR2_REG_KERNEL_HIB_FATAL_ERR_INTVECCTL,
		UNPACKED
	},
};

/* Allows device to enter power save upon driver close(). */
static int allow_power_save = 1;

/* Allows SW based clock gating. */
static int allow_sw_clock_gating;

/* Allows HW based clock gating. */
/* Note: this is not mutual exclusive with SW clock gating. */
static int allow_hw_clock_gating = 1;

/* Act as if only GCB is instantiated. */
static int bypass_top_level;

module_param(allow_power_save, int, 0644);
module_param(allow_sw_clock_gating, int, 0644);
module_param(allow_hw_clock_gating, int, 0644);
module_param(bypass_top_level, int, 0644);

/* Temperature points in milli C at which DFS is toggled */
#define DEFAULT_TRIP_POINT0_TEMP 85000
#define DEFAULT_TRIP_POINT1_TEMP 90000
#define DEFAULT_TRIP_POINT2_TEMP 95000

static int trip_point0_temp = DEFAULT_TRIP_POINT0_TEMP;
static int trip_point1_temp = DEFAULT_TRIP_POINT1_TEMP;
static int trip_point2_temp = DEFAULT_TRIP_POINT2_TEMP;

module_param(trip_point0_temp, int, 0644);
module_param(trip_point1_temp, int, 0644);
module_param(trip_point2_temp, int, 0644);

/* Hardware monitored temperature trip points in milli C
   Apex chip drives INTR line when reaching hw_temp_warn1 temperature,
   and SD_ALARM line when reaching hw_temp_warn2 if corresponding
   hw_temp_warn*_en is set to true.
 */
static int hw_temp_warn1 = 100000;
static int hw_temp_warn2 = 100000;
static bool hw_temp_warn1_en = false;
static bool hw_temp_warn2_en = true;

module_param(hw_temp_warn1, int, 0644);
module_param(hw_temp_warn2, int, 0644);
module_param(hw_temp_warn1_en, bool, 0644);
module_param(hw_temp_warn2_en, bool, 0644);

/* Temperature poll interval in ms */
static int temp_poll_interval = DEFAULT_APEX_TEMP_POLL_INTERVAL;
module_param(temp_poll_interval, int, 0644);

/* Check the device status registers and return device status ALIVE or DEAD. */
static int apex_get_status(struct gasket_dev *gasket_dev)
{
	/* TODO: Check device status. */
	return GASKET_STATUS_ALIVE;
}

/* Enter GCB reset state. */
static int apex_enter_reset(struct gasket_dev *gasket_dev)
{
	if (bypass_top_level)
		return 0;

/*
	 * Software reset:
	 * Enable sleep mode
	 *  - Software force GCB idle
	 *    - Enable GCB idle
	 */
	gasket_read_modify_write_64(gasket_dev, APEX_BAR_INDEX,
				    APEX_BAR2_REG_IDLEGENERATOR_IDLEGEN_IDLEREGISTER,
				    0x0, 1, 32);

/*    - Initiate DMA pause */
	gasket_dev_write_64(gasket_dev, 1, APEX_BAR_INDEX,
			    APEX_BAR2_REG_USER_HIB_DMA_PAUSE);

/*    - Wait for DMA pause complete. */
	if (gasket_wait_with_reschedule(gasket_dev, APEX_BAR_INDEX,
					APEX_BAR2_REG_USER_HIB_DMA_PAUSED, 1, 1,
					APEX_RESET_DELAY, APEX_RESET_RETRY)) {
		dev_err(gasket_dev->dev,
			"DMAs did not quiesce within timeout (%d ms)\n",
			APEX_RESET_RETRY * APEX_RESET_DELAY);
		return -ETIMEDOUT;
	}

/*  - Enable GCB reset (0x1 to rg_rst_gcb) */
	gasket_read_modify_write_32(gasket_dev, APEX_BAR_INDEX,
				    APEX_BAR2_REG_SCU_2, 0x1, 2, 2);

/*  - Enable GCB clock Gate (0x1 to rg_gated_gcb) */
	gasket_read_modify_write_32(gasket_dev, APEX_BAR_INDEX,
				    APEX_BAR2_REG_SCU_2, 0x1, 2, 18);

/*  - Enable GCB memory shut down (0x3 to rg_force_ram_sd) */
	gasket_read_modify_write_32(gasket_dev, APEX_BAR_INDEX,
				    APEX_BAR2_REG_SCU_3, 0x3, 2, 14);

/*    - Wait for RAM shutdown. */
	if (gasket_wait_with_reschedule(gasket_dev, APEX_BAR_INDEX,
					APEX_BAR2_REG_SCU_3, 1 << 6, 1 << 6,
					APEX_RESET_DELAY, APEX_RESET_RETRY)) {
		dev_err(gasket_dev->dev,
			"RAM did not shut down within timeout (%d ms)\n",
			APEX_RESET_RETRY * APEX_RESET_DELAY);
		return -ETIMEDOUT;
	}

return 0;
}

/* Quit GCB reset state. */
static int apex_quit_reset(struct gasket_dev *gasket_dev)
{
	u32 val0, val1;

if (bypass_top_level)
		return 0;

/*
	 * Disable sleep mode:
	 *  - Disable GCB memory shut down:
	 *    - b00: Not forced (HW controlled)
	 *    - b1x: Force disable
	 */
	gasket_read_modify_write_32(gasket_dev, APEX_BAR_INDEX,
				    APEX_BAR2_REG_SCU_3, 0x0, 2, 14);

/*
	 *  - Disable software clock gate:
	 *    - b00: Not forced (HW controlled)
	 *    - b1x: Force disable
	 */
	gasket_read_modify_write_32(gasket_dev, APEX_BAR_INDEX,
				    APEX_BAR2_REG_SCU_2, 0x0, 2, 18);

/*
	 *  - Disable GCB reset (rg_rst_gcb):
	 *    - b00: Not forced (HW controlled)
	 *    - b1x: Force disable = Force not Reset
	 */
	gasket_read_modify_write_32(gasket_dev, APEX_BAR_INDEX,
				    APEX_BAR2_REG_SCU_2, 0x2, 2, 2);

/*    - Wait for RAM enable. */
	if (gasket_wait_with_reschedule(gasket_dev, APEX_BAR_INDEX,
					APEX_BAR2_REG_SCU_3, 1 << 6, 0,
					APEX_RESET_DELAY, APEX_RESET_RETRY)) {
		dev_err(gasket_dev->dev,
			"RAM did not enable within timeout (%d ms)\n",
			APEX_RESET_RETRY * APEX_RESET_DELAY);
		return -ETIMEDOUT;
	}

/*    - Wait for Reset complete. */
	if (gasket_wait_with_reschedule(gasket_dev, APEX_BAR_INDEX,
					APEX_BAR2_REG_SCU_3,
					SCU3_CUR_RST_GCB_BIT_MASK, 0,
					APEX_RESET_DELAY, APEX_RESET_RETRY)) {
		dev_err(gasket_dev->dev,
			"GCB did not leave reset within timeout (%d ms)\n",
			APEX_RESET_RETRY * APEX_RESET_DELAY);
		return -ETIMEDOUT;
	}

if (!allow_hw_clock_gating) {
		val0 = gasket_dev_read_32(gasket_dev, APEX_BAR_INDEX,
					  APEX_BAR2_REG_SCU_3);
		/* Inactive and Sleep mode are disabled. */
		gasket_read_modify_write_32(gasket_dev,
					    APEX_BAR_INDEX,
					    APEX_BAR2_REG_SCU_3, 0x3,
					    SCU3_RG_PWR_STATE_OVR_MASK_WIDTH,
					    SCU3_RG_PWR_STATE_OVR_BIT_OFFSET);
		val1 = gasket_dev_read_32(gasket_dev, APEX_BAR_INDEX,
					  APEX_BAR2_REG_SCU_3);
		dev_dbg(gasket_dev->dev,
			"Disallow HW clock gating 0x%x -> 0x%x\n", val0, val1);
	} else {
		val0 = gasket_dev_read_32(gasket_dev, APEX_BAR_INDEX,
					  APEX_BAR2_REG_SCU_3);
		/* Inactive mode enabled - Sleep mode disabled. */
		gasket_read_modify_write_32(gasket_dev, APEX_BAR_INDEX,
					    APEX_BAR2_REG_SCU_3, 2,
					    SCU3_RG_PWR_STATE_OVR_MASK_WIDTH,
					    SCU3_RG_PWR_STATE_OVR_BIT_OFFSET);
		val1 = gasket_dev_read_32(gasket_dev, APEX_BAR_INDEX,
					  APEX_BAR2_REG_SCU_3);
		dev_dbg(gasket_dev->dev, "Allow HW clock gating 0x%x -> 0x%x\n",
			val0, val1);
	}

return 0;
}

/* Reset the Apex hardware. Called on final close via device_close_cb. */
static int apex_device_cleanup(struct gasket_dev *gasket_dev)
{
	u64 scalar_error;
	u64 hib_error;
	int ret = 0;

hib_error = gasket_dev_read_64(gasket_dev, APEX_BAR_INDEX,
				       APEX_BAR2_REG_USER_HIB_ERROR_STATUS);
	scalar_error = gasket_dev_read_64(gasket_dev, APEX_BAR_INDEX,
					  APEX_BAR2_REG_SCALAR_CORE_ERROR_STATUS);

dev_dbg(gasket_dev->dev,
		"%s 0x%p hib_error 0x%llx scalar_error 0x%llx\n",
		__func__, gasket_dev, hib_error, scalar_error);

if (allow_power_save)
		ret = apex_enter_reset(gasket_dev);

return ret;
}

/* Determine if GCB is in reset state. */
static bool is_gcb_in_reset(struct gasket_dev *gasket_dev)
{
	u32 val = gasket_dev_read_32(gasket_dev, APEX_BAR_INDEX,
				     APEX_BAR2_REG_SCU_3);

/* Masks rg_rst_gcb bit of SCU_CTRL_2 */
	return (val & SCU3_CUR_RST_GCB_BIT_MASK);
}

/* Reset the hardware, then quit reset.  Called on device open. */
static int apex_reset(struct gasket_dev *gasket_dev)
{
	int ret;

if (bypass_top_level)
		return 0;

if (!is_gcb_in_reset(gasket_dev)) {
		/* We are not in reset - toggle the reset bit so as to force
		 * re-init of custom block
		 */
		dev_dbg(gasket_dev->dev, "%s: toggle reset\n", __func__);

ret = apex_enter_reset(gasket_dev);
		if (ret)
			return ret;
	}
	ret = apex_quit_reset(gasket_dev);

return ret;
}

/*
 * Check permissions for Apex ioctls.
 * Returns true if the current user may execute this ioctl, and false otherwise.
 */
static bool apex_ioctl_check_permissions(struct file *filp, uint cmd)
{
	return !!(filp->f_mode & FMODE_WRITE);
}

/* Gates or un-gates Apex clock. */
static long apex_clock_gating(struct gasket_dev *gasket_dev,
			      struct apex_gate_clock_ioctl __user *argp)
{
	struct apex_gate_clock_ioctl ibuf;

if (bypass_top_level || !allow_sw_clock_gating)
		return 0;

if (copy_from_user(&ibuf, argp, sizeof(ibuf)))
		return -EFAULT;

dev_dbg(gasket_dev->dev, "%s %llu\n", __func__, ibuf.enable);

if (ibuf.enable) {
		/* Quiesce AXI, gate GCB clock. */
		gasket_read_modify_write_32(gasket_dev, APEX_BAR_INDEX,
					    APEX_BAR2_REG_AXI_QUIESCE, 0x1, 1,
					    16);
		gasket_read_modify_write_32(gasket_dev, APEX_BAR_INDEX,
					    APEX_BAR2_REG_GCB_CLOCK_GATE, 0x1,
					    2, 18);
	} else {
		/* Un-gate GCB clock, un-quiesce AXI. */
		gasket_read_modify_write_32(gasket_dev, APEX_BAR_INDEX,
					    APEX_BAR2_REG_GCB_CLOCK_GATE, 0x0,
					    2, 18);
		gasket_read_modify_write_32(gasket_dev, APEX_BAR_INDEX,
					    APEX_BAR2_REG_AXI_QUIESCE, 0x0, 1,
					    16);
	}
	return 0;
}

/* apex_set_performance_expectation: Adjust clock rates for Apex. */
static long apex_set_performance_expectation(
	struct gasket_dev *gasket_dev,
	struct apex_performance_expectation_ioctl __user *argp)
{
	struct apex_performance_expectation_ioctl ibuf;
	uint32_t rg_gcb_clk_div = 0;
	uint32_t rg_axi_clk_fixed = 0;
	const int AXI_CLK_FIXED_SHIFT = 2;
	const int MCU_CLK_FIXED_SHIFT = 3;

// 8051 clock is fixed for PCIe, as it's not used at all.
	const uint32_t rg_8051_clk_fixed = 1;

if (bypass_top_level)
		return 0;

if (copy_from_user(&ibuf, argp, sizeof(ibuf)))
		return -EFAULT;

switch (ibuf.performance) {
		case APEX_PERFORMANCE_LOW:
			rg_gcb_clk_div = 3;
			rg_axi_clk_fixed = 0;
			break;

case APEX_PERFORMANCE_MED:
			rg_gcb_clk_div = 2;
			rg_axi_clk_fixed = 0;
			break;

case APEX_PERFORMANCE_HIGH:
			rg_gcb_clk_div = 1;
			rg_axi_clk_fixed = 0;
			break;

case APEX_PERFORMANCE_MAX:
			rg_gcb_clk_div = 0;
			rg_axi_clk_fixed = 0;
			break;

default:
			return -EINVAL;
	}

/*
	 * Set clock rates for GCB, AXI, and 8051:
	 */
	gasket_read_modify_write_32(
		gasket_dev, APEX_BAR_INDEX, APEX_BAR2_REG_SCU_3,
                (rg_gcb_clk_div | (rg_axi_clk_fixed << AXI_CLK_FIXED_SHIFT) | (rg_8051_clk_fixed << MCU_CLK_FIXED_SHIFT)),
                /*mask_width=*/4, /*mask_shift=*/28);

return 0;
}

/* Apex-specific ioctl handler. */
static long apex_ioctl(struct file *filp, uint cmd, void __user *argp)
{
	struct gasket_dev *gasket_dev = filp->private_data;

if (!apex_ioctl_check_permissions(filp, cmd))
		return -EPERM;

switch (cmd) {
	case APEX_IOCTL_GATE_CLOCK:
		return apex_clock_gating(gasket_dev, argp);
	case APEX_IOCTL_PERFORMANCE_EXPECTATION:
		return apex_set_performance_expectation(gasket_dev, argp);
	default:
		return -ENOTTY; /* unknown command */
	}
}

/* Linear fit optimized for 25C-100C */
static int adc_to_millic(int adc)
{
	return (662 - adc) * 250 + 550;
}

static int millic_to_adc(int millic)
{
	return (550 - millic) / 250 + 662;
}

/* Display driver sysfs entries. */
static ssize_t sysfs_show(struct device *device, struct device_attribute *attr,
			  char *buf)
{
	int ret;
	unsigned value, value2, value3, value4;
	struct gasket_dev *gasket_dev;
	struct apex_dev *apex_dev;
	struct gasket_sysfs_attribute *gasket_attr;
	enum sysfs_attribute_type type;

gasket_dev = gasket_sysfs_get_device_data(device);
	if (!gasket_dev) {
		dev_err(device, "No Apex device sysfs mapping found\n");
		return -ENODEV;
	}

if (!gasket_dev->pci_dev ||
	    !(apex_dev = pci_get_drvdata(gasket_dev->pci_dev))) {
		dev_err(device, "Can't find apex_dev data\n");
		gasket_sysfs_put_device_data(device, gasket_dev);
		return -ENODEV;
	}

gasket_attr = gasket_sysfs_get_attr(device, attr);
	if (!gasket_attr) {
		dev_err(device, "No Apex device sysfs attr data found\n");
		gasket_sysfs_put_device_data(device, gasket_dev);
		return -ENODEV;
	}

type = (enum sysfs_attribute_type)gasket_attr->data.attr_type;
	switch (type) {
	case ATTR_KERNEL_HIB_PAGE_TABLE_SIZE:
		ret = scnprintf(buf, PAGE_SIZE, "%u\n",
				gasket_page_table_num_entries(
					gasket_dev->page_table[0]));
		break;
	case ATTR_KERNEL_HIB_SIMPLE_PAGE_TABLE_SIZE:
		ret = scnprintf(buf, PAGE_SIZE, "%u\n",
				gasket_page_table_num_entries(
					gasket_dev->page_table[0]));
		break;
	case ATTR_KERNEL_HIB_NUM_ACTIVE_PAGES:
		ret = scnprintf(buf, PAGE_SIZE, "%u\n",
				gasket_page_table_num_active_pages(
					gasket_dev->page_table[0]));
		break;
	case ATTR_TEMP:
		value = gasket_dev_read_32(gasket_dev, APEX_BAR_INDEX,
					   APEX_BAR2_REG_OMC0_DC);
		value = (value >> 16) & ((1 << 10) - 1);
		ret = scnprintf(buf, PAGE_SIZE, "%i\n", adc_to_millic(value));
		break;
	case ATTR_TEMP_WARN1:
		ret = scnprintf(buf, PAGE_SIZE, "%i\n",
				adc_to_millic(apex_dev->hw_temp_warn1_adc));
		break;
	case ATTR_TEMP_WARN2:
		ret = scnprintf(buf, PAGE_SIZE, "%i\n",
				adc_to_millic(apex_dev->hw_temp_warn2_adc));
		break;
	case ATTR_TEMP_WARN1_EN:
		ret = scnprintf(buf, PAGE_SIZE, "%i\n",
				apex_dev->hw_temp_warn1_en);
		break;
	case ATTR_TEMP_WARN2_EN:
		ret = scnprintf(buf, PAGE_SIZE, "%i\n",
				apex_dev->hw_temp_warn2_en);
		break;
	case ATTR_TEMP_TRIP0:
		ret = scnprintf(buf, PAGE_SIZE, "%i\n",
				adc_to_millic(apex_dev->adc_trip_points[0]));
		break;
	case ATTR_TEMP_TRIP1:
		ret = scnprintf(buf, PAGE_SIZE, "%i\n",
				adc_to_millic(apex_dev->adc_trip_points[1]));
		break;
	case ATTR_TEMP_TRIP2:
		ret = scnprintf(buf, PAGE_SIZE, "%i\n",
				adc_to_millic(apex_dev->adc_trip_points[2]));
		break;
	case ATTR_TEMP_POLL_INTERVAL:
		ret = scnprintf(buf, PAGE_SIZE, "%i\n",
				atomic_read(&apex_dev->temp_poll_interval));
		break;
	case ATTR_UNIQUE_ID:
		value = gasket_dev_read_32(gasket_dev, APEX_BAR_INDEX,
					   APEX_BAR2_REG_EFUSE_DC);
		value2 = gasket_dev_read_32(gasket_dev, APEX_BAR_INDEX,
					    APEX_BAR2_REG_EFUSE_E0);
		value3 = gasket_dev_read_32(gasket_dev, APEX_BAR_INDEX,
					    APEX_BAR2_REG_EFUSE_E4);
		value4 = gasket_dev_read_32(gasket_dev, APEX_BAR_INDEX,
					    APEX_BAR2_REG_EFUSE_E8);
		ret = snprintf(buf, PAGE_SIZE, "%.8x%.8x%.8x%.8x\n", value4,
			       value3, value2, value);
		break;

default:
		dev_dbg(gasket_dev->dev, "Unknown attribute: %s\n",
			attr->attr.name);
		ret = 0;
		break;
	}

gasket_sysfs_put_attr(device, gasket_attr);
	gasket_sysfs_put_device_data(device, gasket_dev);
	return ret;
}

/* Set driver sysfs entries. */
static ssize_t sysfs_store(struct device *device, struct device_attribute *attr,
			   const char *buf, size_t count)
{
	int ret = count, value;
	struct gasket_dev *gasket_dev;
	struct apex_dev *apex_dev;
	struct gasket_sysfs_attribute *gasket_attr;
	enum sysfs_attribute_type type;

if (kstrtoint(buf, 10, &value))
		return -EINVAL;

gasket_dev = gasket_sysfs_get_device_data(device);
	if (!gasket_dev) {
		dev_err(device, "No Apex device sysfs mapping found\n");
		return -ENODEV;
	}

type = (enum sysfs_attribute_type)gasket_attr->data.attr_type;
	switch (type) {
	case ATTR_TEMP_WARN1:
		value = millic_to_adc(value);
		gasket_read_modify_write_32(gasket_dev, APEX_BAR_INDEX,
					    APEX_BAR2_REG_OMC0_D4, value, 10,
					    16);
		apex_dev->hw_temp_warn1_adc = value;
		break;
	case ATTR_TEMP_WARN2:
		value = millic_to_adc(value);
		gasket_read_modify_write_32(gasket_dev, APEX_BAR_INDEX,
					    APEX_BAR2_REG_OMC0_D8, value, 10,
					    16);
		apex_dev->hw_temp_warn2_adc = value;
		break;
	case ATTR_TEMP_WARN1_EN:
		value = value > 0 ? 1 : 0;
		gasket_read_modify_write_32(gasket_dev, APEX_BAR_INDEX,
					    APEX_BAR2_REG_OMC0_D4, value, 1,
					    31);
		apex_dev->hw_temp_warn1_en = !!value;
		break;
	case ATTR_TEMP_WARN2_EN:
		value = value > 0 ? 1 : 0;
		gasket_read_modify_write_32(gasket_dev, APEX_BAR_INDEX,
					    APEX_BAR2_REG_OMC0_D8, value, 1,
					    31);
		apex_dev->hw_temp_warn2_en = !!value;
		break;
	case ATTR_TEMP_TRIP0:
		value = millic_to_adc(value);
		/* Note: that adc values should be in descending order */
		if (value >= apex_dev->adc_trip_points[1]) {
			apex_dev->adc_trip_points[0] = value;
		} else ret = -EINVAL;
		break;
	case ATTR_TEMP_TRIP1:
		value = millic_to_adc(value);
		if (value <= apex_dev->adc_trip_points[0] &&
		    value >= apex_dev->adc_trip_points[2]) {
			apex_dev->adc_trip_points[1] = value;
		} else ret = -EINVAL;
		break;
	case ATTR_TEMP_TRIP2:
		value = millic_to_adc(value);
		if (value <= apex_dev->adc_trip_points[1]) {
			apex_dev->adc_trip_points[2] = value;
		} else ret = -EINVAL;
		break;
	case ATTR_TEMP_POLL_INTERVAL:
		cancel_delayed_work_sync(&apex_dev->check_temperature_work);
		atomic_set(&apex_dev->temp_poll_interval, value);
		if (value > 0)
			schedule_delayed_work(&apex_dev->check_temperature_work,
					      msecs_to_jiffies(value));

break;
	default:
		dev_dbg(gasket_dev->dev, "Unknown attribute: %s\n",
			attr->attr.name);
		ret = 0;
		break;
	}

gasket_sysfs_put_attr(device, gasket_attr);
	gasket_sysfs_put_device_data(device, gasket_dev);
	return ret;
}

static struct gasket_sysfs_attribute apex_sysfs_attrs[] = {
	GASKET_SYSFS_RO(node_0_page_table_entries, sysfs_show,
			ATTR_KERNEL_HIB_PAGE_TABLE_SIZE),
	GASKET_SYSFS_RO(node_0_simple_page_table_entries, sysfs_show,
			ATTR_KERNEL_HIB_SIMPLE_PAGE_TABLE_SIZE),
	GASKET_SYSFS_RO(node_0_num_mapped_pages, sysfs_show,
			ATTR_KERNEL_HIB_NUM_ACTIVE_PAGES),
	GASKET_SYSFS_RO(temp, sysfs_show, ATTR_TEMP),
	GASKET_SYSFS_RW(hw_temp_warn1, sysfs_show, sysfs_store,
			ATTR_TEMP_WARN1),
	GASKET_SYSFS_RW(hw_temp_warn1_en, sysfs_show, sysfs_store,
			ATTR_TEMP_WARN1_EN),
	GASKET_SYSFS_RW(hw_temp_warn2, sysfs_show, sysfs_store,
			ATTR_TEMP_WARN2),
	GASKET_SYSFS_RW(hw_temp_warn2_en, sysfs_show, sysfs_store,
			ATTR_TEMP_WARN2_EN),
	GASKET_SYSFS_RW(trip_point0_temp, sysfs_show, sysfs_store,
			ATTR_TEMP_TRIP0),
	GASKET_SYSFS_RW(trip_point1_temp, sysfs_show, sysfs_store,
			ATTR_TEMP_TRIP1),
	GASKET_SYSFS_RW(trip_point2_temp, sysfs_show, sysfs_store,
			ATTR_TEMP_TRIP2),
	GASKET_SYSFS_RW(temp_poll_interval, sysfs_show, sysfs_store,
			ATTR_TEMP_POLL_INTERVAL),
	GASKET_SYSFS_RO(unique_id, sysfs_show, ATTR_UNIQUE_ID),
	GASKET_END_OF_ATTR_ARRAY
};

/* Stores kernel module parameters to device specific data buffer */
static void apply_module_params(struct apex_dev *apex_dev) {
	kernel_param_lock(THIS_MODULE);

/* use defaults if trip point temperatures are not in ascending order */
	if (trip_point0_temp > trip_point1_temp ||
	    trip_point1_temp > trip_point2_temp) {
		dev_warn(apex_dev->gasket_dev_ptr->dev,
			 "Invalid module parameters for temperature trip points"
			 ", using defaults\n");
		trip_point0_temp = DEFAULT_TRIP_POINT0_TEMP;
		trip_point1_temp = DEFAULT_TRIP_POINT1_TEMP;
		trip_point2_temp = DEFAULT_TRIP_POINT2_TEMP;
	}

apex_dev->adc_trip_points[0] = millic_to_adc(trip_point0_temp);
	apex_dev->adc_trip_points[1] = millic_to_adc(trip_point1_temp);
	apex_dev->adc_trip_points[2] = millic_to_adc(trip_point2_temp);
	atomic_set(&apex_dev->temp_poll_interval, temp_poll_interval);

apex_dev->hw_temp_warn1_adc = millic_to_adc(hw_temp_warn1);
	apex_dev->hw_temp_warn2_adc = millic_to_adc(hw_temp_warn2);
	apex_dev->hw_temp_warn1_en = hw_temp_warn1_en;
	apex_dev->hw_temp_warn2_en = hw_temp_warn2_en;

kernel_param_unlock(THIS_MODULE);
}

/* Applies hw temp warning settings to device */
static void program_hw_temp_warnings(struct apex_dev *apex_dev) {
	gasket_read_modify_write_32(apex_dev->gasket_dev_ptr, APEX_BAR_INDEX,
				    APEX_BAR2_REG_OMC0_D4,
				    apex_dev->hw_temp_warn1_adc, 10, 16);
	gasket_read_modify_write_32(apex_dev->gasket_dev_ptr, APEX_BAR_INDEX,
				    APEX_BAR2_REG_OMC0_D8,
				    apex_dev->hw_temp_warn2_adc, 10, 16);
	if (apex_dev->hw_temp_warn1_en)
		gasket_read_modify_write_32(apex_dev->gasket_dev_ptr,
					    APEX_BAR_INDEX,
					    APEX_BAR2_REG_OMC0_D4, 1, 1, 31);

if (apex_dev->hw_temp_warn2_en)
		gasket_read_modify_write_32(apex_dev->gasket_dev_ptr,
					    APEX_BAR_INDEX,
					    APEX_BAR2_REG_OMC0_D8, 1, 1, 31);
}

static void enable_thermal_sensing(struct gasket_dev *gasket_dev) {
	// Enable thermal sensor clocks
	gasket_read_modify_write_32(gasket_dev, APEX_BAR_INDEX,
				    APEX_BAR2_REG_OMC0_D0, 0x1, 1, 7);

// Enable thermal sensor (ENAD ENVR ENBG)
	gasket_read_modify_write_32(gasket_dev, APEX_BAR_INDEX,
				    APEX_BAR2_REG_OMC0_D8, 0x7, 3, 0);

// Enable OMC thermal sensor controller
	// This bit should be asserted 100 us after ENAD ENVR ENBG
	schedule_timeout(usecs_to_jiffies(100));
	gasket_read_modify_write_32(gasket_dev, APEX_BAR_INDEX,
				    APEX_BAR2_REG_OMC0_DC, 0x1, 1, 0);
}

static void check_temperature_work_handler(struct work_struct *work) {
	int i, temp_poll_interval;
	u32 adc_temp, clk_div, tmp;
	const u32 mask = ((1 << 2) - 1) << 28;
	struct apex_dev *apex_dev =
		container_of(work, struct apex_dev,
			     check_temperature_work.work);
	struct gasket_dev *gasket_dev = apex_dev->gasket_dev_ptr;

mutex_lock(&gasket_dev->mutex);

/* Read current temperature */
	adc_temp = gasket_dev_read_32(gasket_dev, APEX_BAR_INDEX,
				      APEX_BAR2_REG_OMC0_DC);
	adc_temp = (adc_temp >> 16) & ((1 << 10) - 1);

/* Find closest trip point
	   Note: that adc values are in descending order */
	for (i = ARRAY_SIZE(apex_dev->adc_trip_points) - 1; i >= 0; --i) {
		if (adc_temp <= apex_dev->adc_trip_points[i])
			break;
	}
	/* Compute divider value and shift into appropriate bit location */
	clk_div = (i + 1) << 28;

/* Modify gcb clk divider if it's different from current one */
	tmp = gasket_dev_read_32(gasket_dev, APEX_BAR_INDEX,
				 APEX_BAR2_REG_SCU_3);
	if (clk_div != (tmp & mask)) {
		tmp = (tmp & ~mask) | clk_div;
		gasket_dev_write_32(gasket_dev, tmp, APEX_BAR_INDEX,
				    APEX_BAR2_REG_SCU_3);
		dev_warn(gasket_dev->dev,
			 "Apex performance %sthrottled due to temperature\n",
			 i == -1 ? "not " : "");
	}

mutex_unlock(&gasket_dev->mutex);

temp_poll_interval = atomic_read(&apex_dev->temp_poll_interval);
	if (temp_poll_interval > 0)
		schedule_delayed_work(&apex_dev->check_temperature_work,
				      msecs_to_jiffies(temp_poll_interval));
}

/* On device open, perform a core reinit reset. */
static int apex_device_open_cb(struct gasket_dev *gasket_dev)
{
	return gasket_reset_nolock(gasket_dev);
}

static const struct pci_device_id apex_pci_ids[] = {
	{ PCI_DEVICE(APEX_PCI_VENDOR_ID, APEX_PCI_DEVICE_ID) }, { 0 }
};

static void apex_pci_fixup_class(struct pci_dev *pdev)
{
	pdev->class = (PCI_CLASS_SYSTEM_OTHER << 8) | pdev->class;
}
DECLARE_PCI_FIXUP_CLASS_HEADER(APEX_PCI_VENDOR_ID, APEX_PCI_DEVICE_ID,
			       PCI_ANY_ID, 8, apex_pci_fixup_class);

static int apex_pci_probe(struct pci_dev *pci_dev,
			  const struct pci_device_id *id)
{
	int ret, temp_poll_interval;
	ulong page_table_ready, msix_table_ready;
	int retries = 0;
	struct gasket_dev *gasket_dev;
	struct apex_dev *apex_dev;

ret = pci_enable_device(pci_dev);
#ifdef MODULE
	if (ret) {
		apex_pci_fixup_class(pci_dev);
		pci_bus_assign_resources(pci_dev->bus);
		ret = pci_enable_device(pci_dev);
	}
#endif
	if (ret) {
		dev_err(&pci_dev->dev, "error enabling PCI device\n");
		return ret;
	}

pci_set_master(pci_dev);

ret = gasket_pci_add_device(pci_dev, &gasket_dev);
	if (ret) {
		dev_err(&pci_dev->dev, "error adding gasket device\n");
		pci_disable_device(pci_dev);
		return ret;
	}

apex_dev = kzalloc(sizeof(*apex_dev), GFP_KERNEL);
	if (!apex_dev) {
		dev_err(&pci_dev->dev, "no memory for device\n");
		ret = -ENOMEM;
		goto remove_device;
 	}

INIT_DELAYED_WORK(&apex_dev->check_temperature_work,
			  check_temperature_work_handler);
	apex_dev->gasket_dev_ptr = gasket_dev;
	apply_module_params(apex_dev);
	program_hw_temp_warnings(apex_dev);
	pci_set_drvdata(pci_dev, apex_dev);
	apex_reset(gasket_dev);

while (retries < APEX_RESET_RETRY) {
		page_table_ready =
			gasket_dev_read_64(gasket_dev, APEX_BAR_INDEX,
					   APEX_BAR2_REG_KERNEL_HIB_PAGE_TABLE_INIT);
		msix_table_ready =
			gasket_dev_read_64(gasket_dev, APEX_BAR_INDEX,
					   APEX_BAR2_REG_KERNEL_HIB_MSIX_TABLE_INIT);
		if (page_table_ready && msix_table_ready)
			break;
		schedule_timeout(msecs_to_jiffies(APEX_RESET_DELAY));
		retries++;
	}

if (retries == APEX_RESET_RETRY) {
		if (!page_table_ready)
			dev_err(gasket_dev->dev, "Page table init timed out\n");
		if (!msix_table_ready)
			dev_err(gasket_dev->dev, "MSI-X table init timed out\n");
		ret = -ETIMEDOUT;
		goto remove_device;
	}

enable_thermal_sensing(gasket_dev);

ret = gasket_sysfs_create_entries(gasket_dev->dev_info.device,
					  apex_sysfs_attrs);
	if (ret)
		dev_err(&pci_dev->dev, "error creating device sysfs entries\n");

ret = gasket_enable_device(gasket_dev);
	if (ret) {
		dev_err(&pci_dev->dev, "error enabling gasket device\n");
		goto remove_device;
	}

/* Place device in low power mode until opened */
	if (allow_power_save)
		apex_enter_reset(gasket_dev);

/* Enable thermal polling */
	temp_poll_interval = atomic_read(&apex_dev->temp_poll_interval);
	if (temp_poll_interval > 0)
		schedule_delayed_work(&apex_dev->check_temperature_work,
				      msecs_to_jiffies(temp_poll_interval));
	return 0;

remove_device:
	gasket_pci_remove_device(pci_dev);
	pci_disable_device(pci_dev);
	kfree(apex_dev);
	return ret;
}

static void apex_pci_remove(struct pci_dev *pci_dev)
{
	struct apex_dev *apex_dev = pci_get_drvdata(pci_dev);
	struct gasket_dev *gasket_dev;

if (!apex_dev) {
		dev_err(&pci_dev->dev, "NULL apex_dev\n");
		goto remove_device;
	}
	gasket_dev = apex_dev->gasket_dev_ptr;

cancel_delayed_work_sync(&apex_dev->check_temperature_work);
	kfree(apex_dev);

gasket_disable_device(gasket_dev);
remove_device:
	gasket_pci_remove_device(pci_dev);
	pci_disable_device(pci_dev);
}

static int apex_pci_suspend(struct pci_dev *pci_dev, pm_message_t state) {
	struct apex_dev *apex_dev = pci_get_drvdata(pci_dev);
	struct gasket_dev *gasket_dev;

if (!apex_dev) {
		dev_err_once(&pci_dev->dev, "NULL apex_dev\n");
		return -ENODEV;
	}

// Tear down MSI-x interrupts before suspending.
	gasket_dev = apex_dev->gasket_dev_ptr;
	gasket_interrupt_msix_cleanup(gasket_dev->interrupt_data);
	return 0;
}

static int apex_pci_resume(struct pci_dev *pci_dev)
{
	struct apex_dev *apex_dev = pci_get_drvdata(pci_dev);
	struct gasket_dev *gasket_dev;

if (!apex_dev) {
		dev_err_once(&pci_dev->dev, "NULL apex_dev\n");
		return -ENODEV;
	}
	gasket_dev = apex_dev->gasket_dev_ptr;

gasket_interrupt_reinit(gasket_dev);
	apex_reset(gasket_dev);
	program_hw_temp_warnings(apex_dev);
	enable_thermal_sensing(gasket_dev);

/* Place device in low power mode until opened */
	if (allow_power_save)
		apex_enter_reset(gasket_dev);

return 0;
}

static struct gasket_driver_desc apex_desc = {
	.name = "apex",
	.driver_version = APEX_DRIVER_VERSION,
	.major = 120,
	.minor = 0,
	.module = THIS_MODULE,
	.pci_id_table = apex_pci_ids,

.num_page_tables = NUM_NODES,
	.page_table_bar_index = APEX_BAR_INDEX,
	.page_table_configs = apex_page_table_configs,
	.page_table_extended_bit = APEX_EXTENDED_SHIFT,

.bar_descriptions = {
		GASKET_UNUSED_BAR,
		GASKET_UNUSED_BAR,
		{ APEX_BAR_BYTES, (VM_WRITE | VM_READ), APEX_BAR_OFFSET,
			NUM_REGIONS, mappable_regions, PCI_BAR },
		GASKET_UNUSED_BAR,
		GASKET_UNUSED_BAR,
		GASKET_UNUSED_BAR,
	},
	.coherent_buffer_description = {
		APEX_CH_MEM_BYTES,
		(VM_WRITE | VM_READ),
		APEX_CM_OFFSET,
	},
	.interrupt_type = PCI_MSIX,
	.interrupt_bar_index = APEX_BAR_INDEX,
	.num_interrupts = APEX_INTERRUPT_COUNT,
	.interrupts = apex_interrupts,
	.interrupt_pack_width = 7,

.device_open_cb = apex_device_open_cb,
	.device_close_cb = apex_device_cleanup,

.ioctl_handler_cb = apex_ioctl,
	.device_status_cb = apex_get_status,
	.hardware_revision_cb = NULL,
	.device_reset_cb = apex_reset,
};

static struct pci_driver apex_pci_driver = {
	.name = "apex",
	.probe = apex_pci_probe,
	.remove = apex_pci_remove,
#ifdef CONFIG_PM_SLEEP
	.suspend = apex_pci_suspend,
	.resume = apex_pci_resume,
#endif
	.id_table = apex_pci_ids,
};

static int __init apex_init(void)
{
	int ret;

ret = gasket_register_device(&apex_desc);
	if (ret)
		return ret;
	ret = pci_register_driver(&apex_pci_driver);
	if (ret)
		gasket_unregister_device(&apex_desc);
	return ret;
}

static void apex_exit(void)
{
	pci_unregister_driver(&apex_pci_driver);
	gasket_unregister_device(&apex_desc);
}
MODULE_DESCRIPTION("Google Apex driver");
MODULE_VERSION(APEX_DRIVER_VERSION);
MODULE_LICENSE("GPL v2");
MODULE_AUTHOR("John Joseph <jnjoseph@google.com>");
MODULE_DEVICE_TABLE(pci, apex_pci_ids);
module_init(apex_init);
module_exit(apex_exit);
07070100000012000081A40000000000000000000000016217DF4F000016DD000000000000000000000000000000000000002200000000gasket-driver-1.0.18/src/gasket.h/* SPDX-License-Identifier: GPL-2.0 */
/*
 * Common Gasket device kernel and user space declarations.
 *
 * Copyright (C) 2018 Google, Inc.
 */
#ifndef __GASKET_H__
#define __GASKET_H__

#include <linux/ioctl.h>
#include <linux/types.h>

/* ioctl structure declarations */

/* Ioctl structures are padded to a multiple of 64 bits */
/* and padded to put 64 bit values on 64 bit boundaries. */
/* Unsigned 64 bit integers are used to hold pointers. */
/* This helps compatibility between 32 and 64 bits. */

/*
 * Common structure for ioctls associating an eventfd with a device interrupt,
 * when using the Gasket interrupt module.
 */
struct gasket_interrupt_eventfd {
	u64 interrupt;
	u64 event_fd;
};

/*
 * Common structure for ioctls mapping and unmapping buffers when using the
 * Gasket page_table module.
 */
struct gasket_page_table_ioctl {
	u64 page_table_index;
	u64 size;
	u64 host_address;
	u64 device_address;
};

/*
 * Structure for ioctl mapping buffers with flags when using the Gasket
 * page_table module.
 */
struct gasket_page_table_ioctl_flags {
	struct gasket_page_table_ioctl base;
	/*
	 * Flags indicating status and attribute requests from the host.
	 * NOTE: STATUS bit does not need to be set in this request.
	 *       Set RESERVED bits to 0 to ensure backwards compatibility.
	 *
	 * Bitfields:
	 *   [0]     - STATUS: indicates if this entry/slot is free
	 *                0 = PTE_FREE
	 *                1 = PTE_INUSE
	 *   [2:1]   - DMA_DIRECTION: dma_data_direction requested by host
	 *               00 = DMA_BIDIRECTIONAL
	 *               01 = DMA_TO_DEVICE
	 *               10 = DMA_FROM_DEVICE
	 *               11 = DMA_NONE
	 *   [31:3]  - RESERVED
	 */
	u32 flags;
};

/*
 * Common structure for ioctls mapping and unmapping buffers when using the
 * Gasket page_table module.
 * dma_address: phys addr start of coherent memory, allocated by kernel
 */
struct gasket_coherent_alloc_config_ioctl {
	u64 page_table_index;
	u64 enable;
	u64 size;
	u64 dma_address;
};

/*
 * Common structure for ioctls mapping and unmapping dma-bufs when using the
 * Gasket page_table module.
 * map: boolean, non-zero to map, 0 to unmap.
 * flags: see gasket_page_table_ioctl_flags.flags.
 */
struct gasket_page_table_ioctl_dmabuf {
	u64 page_table_index;
	u64 device_address;
	int dmabuf_fd;
	u32 num_pages;
	u32 map;
	u32 flags;
};

/* Base number for all Gasket-common IOCTLs */
#define GASKET_IOCTL_BASE 0xDC

/* Reset the device. */
#define GASKET_IOCTL_RESET _IO(GASKET_IOCTL_BASE, 0)

/* Associate the specified [event]fd with the specified interrupt. */
#define GASKET_IOCTL_SET_EVENTFD                                               \
	_IOW(GASKET_IOCTL_BASE, 1, struct gasket_interrupt_eventfd)

/*
 * Clears any eventfd associated with the specified interrupt. The (ulong)
 * argument is the interrupt number to clear.
 */
#define GASKET_IOCTL_CLEAR_EVENTFD _IOW(GASKET_IOCTL_BASE, 2, unsigned long)

/*
 * [Loopbacks only] Requests that the loopback device send the specified
 * interrupt to the host. The (ulong) argument is the number of the interrupt to
 * send.
 */
#define GASKET_IOCTL_LOOPBACK_INTERRUPT                                        \
	_IOW(GASKET_IOCTL_BASE, 3, unsigned long)

/* Queries the kernel for the number of page tables supported by the device. */
#define GASKET_IOCTL_NUMBER_PAGE_TABLES _IOR(GASKET_IOCTL_BASE, 4, u64)

/*
 * Queries the kernel for the maximum size of the page table.  Only the size and
 * page_table_index fields are used from the struct gasket_page_table_ioctl.
 */
#define GASKET_IOCTL_PAGE_TABLE_SIZE                                           \
	_IOWR(GASKET_IOCTL_BASE, 5, struct gasket_page_table_ioctl)

/*
 * Queries the kernel for the current simple page table size.  Only the size and
 * page_table_index fields are used from the struct gasket_page_table_ioctl.
 */
#define GASKET_IOCTL_SIMPLE_PAGE_TABLE_SIZE                                    \
	_IOWR(GASKET_IOCTL_BASE, 6, struct gasket_page_table_ioctl)

/*
 * Tells the kernel to change the split between the number of simple and
 * extended entries in the given page table. Only the size and page_table_index
 * fields are used from the struct gasket_page_table_ioctl.
 */
#define GASKET_IOCTL_PARTITION_PAGE_TABLE                                      \
	_IOW(GASKET_IOCTL_BASE, 7, struct gasket_page_table_ioctl)

/*
 * Tells the kernel to map size bytes at host_address to device_address in
 * page_table_index page table.
 */
#define GASKET_IOCTL_MAP_BUFFER                                                \
	_IOW(GASKET_IOCTL_BASE, 8, struct gasket_page_table_ioctl)

/*
 * Tells the kernel to unmap size bytes at host_address from device_address in
 * page_table_index page table.
 */
#define GASKET_IOCTL_UNMAP_BUFFER                                              \
	_IOW(GASKET_IOCTL_BASE, 9, struct gasket_page_table_ioctl)

/* Clear the interrupt counts stored for this device. */
#define GASKET_IOCTL_CLEAR_INTERRUPT_COUNTS _IO(GASKET_IOCTL_BASE, 10)

/* Enable/Disable and configure the coherent allocator. */
#define GASKET_IOCTL_CONFIG_COHERENT_ALLOCATOR                                 \
	_IOWR(GASKET_IOCTL_BASE, 11, struct gasket_coherent_alloc_config_ioctl)

/*
 * Tells the kernel to map size bytes at host_address to device_address in
 * page_table_index page table. Passes flags to indicate additional attribute
 * requests for the mapped memory.
 */
#define GASKET_IOCTL_MAP_BUFFER_FLAGS                                          \
	_IOW(GASKET_IOCTL_BASE, 12, struct gasket_page_table_ioctl_flags)

/*
 * Tells the kernel to map/unmap dma-buf with fd to device_address in
 * page_table_index page table.
 */
#define GASKET_IOCTL_MAP_DMABUF                                                \
	_IOW(GASKET_IOCTL_BASE, 13, struct gasket_page_table_ioctl_dmabuf)

#endif /* __GASKET_H__ */
07070100000013000081A40000000000000000000000016217DF4F000004B6000000000000000000000000000000000000002C00000000gasket-driver-1.0.18/src/gasket_constants.h/* SPDX-License-Identifier: GPL-2.0 */
/* Copyright (C) 2018 Google, Inc. */
#ifndef __GASKET_CONSTANTS_H__
#define __GASKET_CONSTANTS_H__

#define GASKET_FRAMEWORK_VERSION "1.1.4"

/*
 * The maximum number of simultaneous device types supported by the framework.
 */
#define GASKET_FRAMEWORK_DESC_MAX 2

/* The maximum devices per each type. */
#define GASKET_DEV_MAX 256

/* The number of supported (and possible) PCI BARs. */
#define GASKET_NUM_BARS 6

/* The number of supported Gasket page tables per device. */
#define GASKET_MAX_NUM_PAGE_TABLES 1

/* Maximum length of device names (driver name + minor number suffix + NULL). */
#define GASKET_NAME_MAX 32

/* Device status enumeration. */
enum gasket_status {
	/*
	 * A device is DEAD if it has not been initialized or has had an error.
	 */
	GASKET_STATUS_DEAD = 0,
	/*
	 * A device is LAMED if the hardware is healthy but the kernel was
	 * unable to enable some functionality (e.g. interrupts).
	 */
	GASKET_STATUS_LAMED,

/* A device is ALIVE if it is ready for operation. */
	GASKET_STATUS_ALIVE,

/*
	 * This status is set when the driver is exiting and waiting for all
	 * handles to be closed.
	 */
	GASKET_STATUS_DRIVER_EXIT,
};

#endif
07070100000014000081A40000000000000000000000016217DF4F0000D54B000000000000000000000000000000000000002700000000gasket-driver-1.0.18/src/gasket_core.c// SPDX-License-Identifier: GPL-2.0
/*
 * Gasket generic driver framework. This file contains the implementation
 * for the Gasket generic driver framework - the functionality that is common
 * across Gasket devices.
 *
 * Copyright (C) 2018 Google, Inc.
 */

#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt

#include "gasket_core.h"

#include "gasket_interrupt.h"
#include "gasket_ioctl.h"
#include "gasket_page_table.h"
#include "gasket_sysfs.h"

#include <linux/capability.h>
#include <linux/compiler.h>
#include <linux/delay.h>
#include <linux/device.h>
#include <linux/fs.h>
#include <linux/init.h>
#include <linux/of.h>
#include <linux/pid_namespace.h>
#include <linux/platform_device.h>
#include <linux/printk.h>
#include <linux/sched.h>

#ifdef GASKET_KERNEL_TRACE_SUPPORT
#define CREATE_TRACE_POINTS
#include <trace/events/gasket_mmap.h>
#else
#define trace_gasket_mmap_exit(x)
#define trace_gasket_mmap_entry(x, ...)
#endif

/*
 * "Private" members of gasket_driver_desc.
 *
 * Contains internal per-device type tracking data, i.e., data not appropriate
 * as part of the public interface for the generic framework.
 */
struct gasket_internal_desc {
	/* Device-specific-driver-provided configuration information. */
	const struct gasket_driver_desc *driver_desc;

/* Protects access to per-driver data (i.e. this structure). */
	struct mutex mutex;

/* Kernel-internal device class. */
	struct class *class;

/* Instantiated / present devices of this type. */
	struct gasket_dev *devs[GASKET_DEV_MAX];
};

/* do_map_region() needs be able to return more than just true/false. */
enum do_map_region_status {
	/* The region was successfully mapped. */
	DO_MAP_REGION_SUCCESS,

/* Attempted to map region and failed. */
	DO_MAP_REGION_FAILURE,

/* The requested region to map was not part of a mappable region. */
	DO_MAP_REGION_INVALID,
};

/* Global data definitions. */
/* Mutex - only for framework-wide data. Other data should be protected by
 * finer-grained locks.
 */
static DEFINE_MUTEX(g_mutex);

/* List of all registered device descriptions & their supporting data. */
static struct gasket_internal_desc g_descs[GASKET_FRAMEWORK_DESC_MAX];

/* Mapping of statuses to human-readable strings. Must end with {0,NULL}. */
static const struct gasket_num_name gasket_status_name_table[] = {
	{ GASKET_STATUS_DEAD, "DEAD" },
	{ GASKET_STATUS_ALIVE, "ALIVE" },
	{ GASKET_STATUS_LAMED, "LAMED" },
	{ GASKET_STATUS_DRIVER_EXIT, "DRIVER_EXITING" },
	{ 0, NULL },
};

/* Enumeration of the automatic Gasket framework sysfs nodes. */
enum gasket_sysfs_attribute_type {
	ATTR_BAR_OFFSETS,
	ATTR_BAR_SIZES,
	ATTR_DRIVER_VERSION,
	ATTR_FRAMEWORK_VERSION,
	ATTR_DEVICE_TYPE,
	ATTR_HARDWARE_REVISION,
	ATTR_PCI_ADDRESS,
	ATTR_STATUS,
	ATTR_IS_DEVICE_OWNED,
	ATTR_DEVICE_OWNER,
	ATTR_WRITE_OPEN_COUNT,
	ATTR_RESET_COUNT,
	ATTR_USER_MEM_RANGES
};

/* On some arm64 systems pcie dma controller can only access lower 4GB of
 * addresses. Unfortunately vendor BSP isn't providing any means of determining
 * this limitation and there're no errors reported if access to higher addresses
 * if being done. This parameter allows to workaround this issue by pretending
 * that our device only supports 32 bit addresses. This in turn will cause
 * dma driver to use shadow buffers located in low 32 bit address space.
 */
static int dma_bit_mask = 64;
module_param(dma_bit_mask, int, 0644);

/* Perform a standard Gasket callback. */
static inline int
check_and_invoke_callback(struct gasket_dev *gasket_dev,
			  int (*cb_function)(struct gasket_dev *))
{
	int ret = 0;

if (cb_function) {
		mutex_lock(&gasket_dev->mutex);
		ret = cb_function(gasket_dev);
		mutex_unlock(&gasket_dev->mutex);
	}
	return ret;
}

/* Perform a standard Gasket callback without grabbing gasket_dev->mutex. */
static inline int
gasket_check_and_invoke_callback_nolock(struct gasket_dev *gasket_dev,
					int (*cb_function)(struct gasket_dev *))
{
	int ret = 0;

if (cb_function)
		ret = cb_function(gasket_dev);
	return ret;
}

/*
 * Return nonzero if the gasket_cdev_info is owned by the current thread group
 * ID.
 */
static int gasket_owned_by_current_tgid(struct gasket_cdev_info *info)
{
	return (info->ownership.is_owned &&
		(info->ownership.owner == current->tgid));
}

/*
 * Find the next free gasket_internal_dev slot.
 *
 * Returns the located slot number on success or a negative number on failure.
 */
static int gasket_find_dev_slot(struct gasket_internal_desc *internal_desc,
				const char *kobj_name)
{
	int i;

mutex_lock(&internal_desc->mutex);

/* Search for a previous instance of this device. */
	for (i = 0; i < GASKET_DEV_MAX; i++) {
		if (internal_desc->devs[i] &&
		    strcmp(internal_desc->devs[i]->kobj_name, kobj_name) == 0) {
			pr_err("Duplicate device %s\n", kobj_name);
			mutex_unlock(&internal_desc->mutex);
			return -EBUSY;
		}
	}

/* Find a free device slot. */
	for (i = 0; i < GASKET_DEV_MAX; i++) {
		if (!internal_desc->devs[i])
			break;
	}

if (i == GASKET_DEV_MAX) {
		pr_err("Too many registered devices; max %d\n", GASKET_DEV_MAX);
		mutex_unlock(&internal_desc->mutex);
		return -EBUSY;
	}

mutex_unlock(&internal_desc->mutex);
	return i;
}

/*
 * Allocate and initialize a Gasket device structure, add the device to the
 * device list.
 *
 * Returns 0 if successful, a negative error code otherwise.
 */
static int gasket_alloc_dev(struct gasket_internal_desc *internal_desc,
			    struct device *parent, struct gasket_dev **pdev)
{
	int dev_idx;
	const struct gasket_driver_desc *driver_desc =
		internal_desc->driver_desc;
	struct gasket_dev *gasket_dev;
	struct gasket_cdev_info *dev_info;
	const char *parent_name = dev_name(parent);

pr_debug("Allocating a Gasket device, parent %s.\n", parent_name);

*pdev = NULL;

dev_idx = gasket_find_dev_slot(internal_desc, parent_name);
	if (dev_idx < 0)
		return dev_idx;

gasket_dev = *pdev = kzalloc(sizeof(*gasket_dev), GFP_KERNEL);
	if (!gasket_dev) {
		pr_err("no memory for device, parent %s\n", parent_name);
		return -ENOMEM;
	}
	internal_desc->devs[dev_idx] = gasket_dev;

mutex_init(&gasket_dev->mutex);

gasket_dev->internal_desc = internal_desc;
	gasket_dev->dev_idx = dev_idx;
	snprintf(gasket_dev->kobj_name, GASKET_NAME_MAX, "%s", parent_name);
	gasket_dev->dev = get_device(parent);
	gasket_dev->dma_dev = get_device(parent);
	/* gasket_bar_data is uninitialized. */
	gasket_dev->num_page_tables = driver_desc->num_page_tables;
	/* max_page_table_size and *page table are uninit'ed */
	/* interrupt_data is not initialized. */
	/* status is 0, or GASKET_STATUS_DEAD */

dev_info = &gasket_dev->dev_info;
	snprintf(dev_info->name, GASKET_NAME_MAX, "%s_%u", driver_desc->name,
		 gasket_dev->dev_idx);
	dev_info->devt =
		MKDEV(driver_desc->major, driver_desc->minor +
		      gasket_dev->dev_idx);
	dev_info->device =
		device_create(internal_desc->class, parent, dev_info->devt,
			      gasket_dev, dev_info->name);

/* cdev has not yet been added; cdev_added is 0 */
	dev_info->gasket_dev_ptr = gasket_dev;
	/* ownership is all 0, indicating no owner or opens. */

return 0;
}

/* Free a Gasket device. */
static void gasket_free_dev(struct gasket_dev *gasket_dev)
{
	struct gasket_internal_desc *internal_desc = gasket_dev->internal_desc;

mutex_lock(&internal_desc->mutex);
	internal_desc->devs[gasket_dev->dev_idx] = NULL;
	mutex_unlock(&internal_desc->mutex);
	put_device(gasket_dev->dev);
	put_device(gasket_dev->dma_dev);
	kfree(gasket_dev);
}

/*
 * Maps the specified bar into kernel space.
 *
 * Returns 0 on success, a negative error code otherwise.
 * A zero-sized BAR will not be mapped, but is not an error.
 */
static int gasket_map_pci_bar(struct gasket_dev *gasket_dev, int bar_num)
{
	struct gasket_internal_desc *internal_desc = gasket_dev->internal_desc;
	const struct gasket_driver_desc *driver_desc =
		internal_desc->driver_desc;
	ulong desc_bytes = driver_desc->bar_descriptions[bar_num].size;
	int ret;

if (desc_bytes == 0)
		return 0;

if (driver_desc->bar_descriptions[bar_num].type != PCI_BAR) {
		/* not PCI: skip this entry */
		return 0;
	}
	/*
	 * pci_resource_start and pci_resource_len return a "resource_size_t",
	 * which is safely castable to ulong (which itself is the arg to
	 * request_mem_region).
	 */
	gasket_dev->bar_data[bar_num].phys_base =
		(ulong)pci_resource_start(gasket_dev->pci_dev, bar_num);
	if (!gasket_dev->bar_data[bar_num].phys_base) {
		dev_err(gasket_dev->dev, "Cannot get BAR%u base address\n",
			bar_num);
		return -EINVAL;
	}

gasket_dev->bar_data[bar_num].length_bytes =
		(ulong)pci_resource_len(gasket_dev->pci_dev, bar_num);
	if (gasket_dev->bar_data[bar_num].length_bytes < desc_bytes) {
		dev_err(gasket_dev->dev,
			"PCI BAR %u space is too small: %lu; expected >= %lu\n",
			bar_num, gasket_dev->bar_data[bar_num].length_bytes,
			desc_bytes);
		return -ENOMEM;
	}

if (!request_mem_region(gasket_dev->bar_data[bar_num].phys_base,
				gasket_dev->bar_data[bar_num].length_bytes,
				gasket_dev->dev_info.name)) {
		dev_err(gasket_dev->dev,
			"Cannot get BAR %d memory region %p\n",
			bar_num, &gasket_dev->pci_dev->resource[bar_num]);
		return -EINVAL;
	}

gasket_dev->bar_data[bar_num].virt_base =
		ioremap(gasket_dev->bar_data[bar_num].phys_base,
			gasket_dev->bar_data[bar_num].length_bytes);
	if (!gasket_dev->bar_data[bar_num].virt_base) {
		dev_err(gasket_dev->dev,
			"Cannot remap BAR %d memory region %p\n",
			bar_num, &gasket_dev->pci_dev->resource[bar_num]);
		ret = -ENOMEM;
		goto fail;
	}

dma_set_mask(&gasket_dev->pci_dev->dev, DMA_BIT_MASK(dma_bit_mask));
	dma_set_coherent_mask(&gasket_dev->pci_dev->dev,
			      DMA_BIT_MASK(dma_bit_mask));

return 0;

fail:
	iounmap(gasket_dev->bar_data[bar_num].virt_base);
	release_mem_region(gasket_dev->bar_data[bar_num].phys_base,
			   gasket_dev->bar_data[bar_num].length_bytes);
	return ret;
}

/*
 * Releases PCI BAR mapping.
 *
 * A zero-sized or not-mapped BAR will not be unmapped, but is not an error.
 */
static void gasket_unmap_pci_bar(struct gasket_dev *dev, int bar_num)
{
	ulong base, bytes;
	struct gasket_internal_desc *internal_desc = dev->internal_desc;
	const struct gasket_driver_desc *driver_desc =
		internal_desc->driver_desc;

if (driver_desc->bar_descriptions[bar_num].size == 0 ||
	    !dev->bar_data[bar_num].virt_base)
		return;

if (driver_desc->bar_descriptions[bar_num].type != PCI_BAR)
		return;

iounmap(dev->bar_data[bar_num].virt_base);
	dev->bar_data[bar_num].virt_base = NULL;

base = pci_resource_start(dev->pci_dev, bar_num);
	if (!base) {
		dev_err(dev->dev, "cannot get PCI BAR%u base address\n",
			bar_num);
		return;
	}

bytes = pci_resource_len(dev->pci_dev, bar_num);
	release_mem_region(base, bytes);
}

/*
 * Setup PCI memory mapping for the specified device.
 *
 * Reads the BAR registers and sets up pointers to the device's memory mapped
 * IO space.
 *
 * Returns 0 on success and a negative value otherwise.
 */
static int gasket_setup_pci(struct pci_dev *pci_dev,
			    struct gasket_dev *gasket_dev)
{
	int i, mapped_bars, ret;

for (i = 0; i < GASKET_NUM_BARS; i++) {
		ret = gasket_map_pci_bar(gasket_dev, i);
		if (ret) {
			mapped_bars = i;
			goto fail;
		}
	}

return 0;

fail:
	for (i = 0; i < mapped_bars; i++)
		gasket_unmap_pci_bar(gasket_dev, i);

return -ENOMEM;
}

/* Unmaps memory for the specified device. */
static void gasket_cleanup_pci(struct gasket_dev *gasket_dev)
{
	int i;

for (i = 0; i < GASKET_NUM_BARS; i++)
		gasket_unmap_pci_bar(gasket_dev, i);
}

/* Determine the health of the Gasket device. */
static int gasket_get_hw_status(struct gasket_dev *gasket_dev)
{
	int status;
	int i;
	const struct gasket_driver_desc *driver_desc =
		gasket_dev->internal_desc->driver_desc;

status = gasket_check_and_invoke_callback_nolock(gasket_dev,
							 driver_desc->device_status_cb);
	if (status != GASKET_STATUS_ALIVE) {
		dev_dbg(gasket_dev->dev, "Hardware reported status %d.\n",
			status);
		return status;
	}

status = gasket_interrupt_system_status(gasket_dev);
	if (status != GASKET_STATUS_ALIVE) {
		dev_dbg(gasket_dev->dev,
			"Interrupt system reported status %d.\n", status);
		return status;
	}

for (i = 0; i < driver_desc->num_page_tables; ++i) {
		status = gasket_page_table_system_status(gasket_dev->page_table[i]);
		if (status != GASKET_STATUS_ALIVE) {
			dev_dbg(gasket_dev->dev,
				"Page table %d reported status %d.\n",
				i, status);
			return status;
		}
	}

return GASKET_STATUS_ALIVE;
}

static ssize_t
gasket_write_mappable_regions(char *buf,
			      const struct gasket_driver_desc *driver_desc,
			      int bar_index)
{
	int i;
	ssize_t written;
	ssize_t total_written = 0;
	ulong min_addr, max_addr;
	struct gasket_bar_desc bar_desc =
		driver_desc->bar_descriptions[bar_index];

if (bar_desc.permissions == GASKET_NOMAP)
		return 0;
	for (i = 0;
	     i < bar_desc.num_mappable_regions && total_written < PAGE_SIZE;
	     i++) {
		min_addr = bar_desc.mappable_regions[i].start -
			   driver_desc->legacy_mmap_address_offset;
		max_addr = bar_desc.mappable_regions[i].start -
			   driver_desc->legacy_mmap_address_offset +
			   bar_desc.mappable_regions[i].length_bytes;
		written = scnprintf(buf, PAGE_SIZE - total_written,
				    "0x%08lx-0x%08lx\n", min_addr, max_addr);
		total_written += written;
		buf += written;
	}
	return total_written;
}

static ssize_t gasket_sysfs_data_show(struct device *device,
				      struct device_attribute *attr, char *buf)
{
	int i, ret = 0;
	ssize_t current_written = 0;
	const struct gasket_driver_desc *driver_desc;
	struct gasket_dev *gasket_dev;
	struct gasket_sysfs_attribute *gasket_attr;
	const struct gasket_bar_desc *bar_desc;
	enum gasket_sysfs_attribute_type sysfs_type;

gasket_dev = gasket_sysfs_get_device_data(device);
	if (!gasket_dev) {
		dev_err(device, "No sysfs mapping found for device\n");
		return 0;
	}

gasket_attr = gasket_sysfs_get_attr(device, attr);
	if (!gasket_attr) {
		dev_err(device, "No sysfs attr found for device\n");
		gasket_sysfs_put_device_data(device, gasket_dev);
		return 0;
	}

driver_desc = gasket_dev->internal_desc->driver_desc;

sysfs_type =
		(enum gasket_sysfs_attribute_type)gasket_attr->data.attr_type;
	switch (sysfs_type) {
	case ATTR_BAR_OFFSETS:
		for (i = 0; i < GASKET_NUM_BARS; i++) {
			bar_desc = &driver_desc->bar_descriptions[i];
			if (bar_desc->size == 0)
				continue;
			current_written =
				snprintf(buf, PAGE_SIZE - ret, "%d: 0x%lx\n", i,
					 (ulong)bar_desc->base);
			buf += current_written;
			ret += current_written;
		}
		break;
	case ATTR_BAR_SIZES:
		for (i = 0; i < GASKET_NUM_BARS; i++) {
			bar_desc = &driver_desc->bar_descriptions[i];
			if (bar_desc->size == 0)
				continue;
			current_written =
				snprintf(buf, PAGE_SIZE - ret, "%d: 0x%lx\n", i,
					 (ulong)bar_desc->size);
			buf += current_written;
			ret += current_written;
		}
		break;
	case ATTR_DRIVER_VERSION:
		ret = snprintf(buf, PAGE_SIZE, "%s\n",
			       gasket_dev->internal_desc->driver_desc->driver_version);
		break;
	case ATTR_FRAMEWORK_VERSION:
		ret = snprintf(buf, PAGE_SIZE, "%s\n",
			       GASKET_FRAMEWORK_VERSION);
		break;
	case ATTR_DEVICE_TYPE:
		ret = snprintf(buf, PAGE_SIZE, "%s\n",
			       gasket_dev->internal_desc->driver_desc->name);
		break;
	case ATTR_HARDWARE_REVISION:
		ret = snprintf(buf, PAGE_SIZE, "%d\n",
			       gasket_dev->hardware_revision);
		break;
	case ATTR_PCI_ADDRESS:
		ret = snprintf(buf, PAGE_SIZE, "%s\n", gasket_dev->kobj_name);
		break;
	case ATTR_STATUS:
		ret = snprintf(buf, PAGE_SIZE, "%s\n",
			       gasket_num_name_lookup(gasket_dev->status,
						      gasket_status_name_table));
		break;
	case ATTR_IS_DEVICE_OWNED:
		ret = snprintf(buf, PAGE_SIZE, "%d\n",
			       gasket_dev->dev_info.ownership.is_owned);
		break;
	case ATTR_DEVICE_OWNER:
		ret = snprintf(buf, PAGE_SIZE, "%d\n",
			       gasket_dev->dev_info.ownership.owner);
		break;
	case ATTR_WRITE_OPEN_COUNT:
		ret = snprintf(buf, PAGE_SIZE, "%d\n",
			       gasket_dev->dev_info.ownership.write_open_count);
		break;
	case ATTR_RESET_COUNT:
		ret = snprintf(buf, PAGE_SIZE, "%d\n", gasket_dev->reset_count);
		break;
	case ATTR_USER_MEM_RANGES:
		for (i = 0; i < GASKET_NUM_BARS; ++i) {
			current_written =
				gasket_write_mappable_regions(buf, driver_desc,
							      i);
			buf += current_written;
			ret += current_written;
		}
		break;
	default:
		dev_dbg(gasket_dev->dev, "Unknown attribute: %s\n",
			attr->attr.name);
		ret = 0;
		break;
	}

gasket_sysfs_put_attr(device, gasket_attr);
	gasket_sysfs_put_device_data(device, gasket_dev);
	return ret;
}

/* These attributes apply to all Gasket driver instances. */
static const struct gasket_sysfs_attribute gasket_sysfs_generic_attrs[] = {
	GASKET_SYSFS_RO(bar_offsets, gasket_sysfs_data_show, ATTR_BAR_OFFSETS),
	GASKET_SYSFS_RO(bar_sizes, gasket_sysfs_data_show, ATTR_BAR_SIZES),
	GASKET_SYSFS_RO(driver_version, gasket_sysfs_data_show,
			ATTR_DRIVER_VERSION),
	GASKET_SYSFS_RO(framework_version, gasket_sysfs_data_show,
			ATTR_FRAMEWORK_VERSION),
	GASKET_SYSFS_RO(device_type, gasket_sysfs_data_show, ATTR_DEVICE_TYPE),
	GASKET_SYSFS_RO(revision, gasket_sysfs_data_show,
			ATTR_HARDWARE_REVISION),
	GASKET_SYSFS_RO(pci_address, gasket_sysfs_data_show, ATTR_PCI_ADDRESS),
	GASKET_SYSFS_RO(status, gasket_sysfs_data_show, ATTR_STATUS),
	GASKET_SYSFS_RO(is_device_owned, gasket_sysfs_data_show,
			ATTR_IS_DEVICE_OWNED),
	GASKET_SYSFS_RO(device_owner, gasket_sysfs_data_show,
			ATTR_DEVICE_OWNER),
	GASKET_SYSFS_RO(write_open_count, gasket_sysfs_data_show,
			ATTR_WRITE_OPEN_COUNT),
	GASKET_SYSFS_RO(reset_count, gasket_sysfs_data_show, ATTR_RESET_COUNT),
	GASKET_SYSFS_RO(user_mem_ranges, gasket_sysfs_data_show,
			ATTR_USER_MEM_RANGES),
	GASKET_END_OF_ATTR_ARRAY
};

/* Add a char device and related info. */
static int gasket_add_cdev(struct gasket_cdev_info *dev_info,
			   const struct file_operations *file_ops,
			   struct module *owner)
{
	int ret;

cdev_init(&dev_info->cdev, file_ops);
	dev_info->cdev.owner = owner;
	ret = cdev_add(&dev_info->cdev, dev_info->devt, 1);
	if (ret) {
		dev_err(dev_info->gasket_dev_ptr->dev,
			"cannot add char device [ret=%d]\n", ret);
		return ret;
	}
	dev_info->cdev_added = 1;

return 0;
}

/* Disable device operations. */
void gasket_disable_device(struct gasket_dev *gasket_dev)
{
	const struct gasket_driver_desc *driver_desc =
		gasket_dev->internal_desc->driver_desc;
	int i;

dev_dbg(gasket_dev->dev, "disabling device\n");
	/* Only delete the device if it has been successfully added. */
	if (gasket_dev->dev_info.cdev_added)
		cdev_del(&gasket_dev->dev_info.cdev);

gasket_dev->status = GASKET_STATUS_DEAD;

gasket_interrupt_cleanup(gasket_dev);

for (i = 0; i < driver_desc->num_page_tables; ++i) {
		if (gasket_dev->page_table[i]) {
			gasket_page_table_reset(gasket_dev->page_table[i]);
			gasket_page_table_cleanup(gasket_dev->page_table[i]);
		}
	}
}
EXPORT_SYMBOL(gasket_disable_device);

/*
 * Registered driver descriptor lookup for PCI devices.
 *
 * Precondition: Called with g_mutex held (to avoid a race on return).
 * Returns NULL if no matching device was found.
 */
static struct gasket_internal_desc *
lookup_pci_internal_desc(struct pci_dev *pci_dev)
{
	int i;

__must_hold(&g_mutex);
	for (i = 0; i < GASKET_FRAMEWORK_DESC_MAX; i++) {
		if (g_descs[i].driver_desc &&
		    g_descs[i].driver_desc->pci_id_table &&
		    pci_match_id(g_descs[i].driver_desc->pci_id_table, pci_dev))
			return &g_descs[i];
	}

return NULL;
}

/*
 * Registered driver descriptor lookup for platform devices.
 * Caller must hold g_mutex.
 */
static struct gasket_internal_desc *
lookup_platform_internal_desc(struct platform_device *pdev)
{
	int i;

__must_hold(&g_mutex);
	for (i = 0; i < GASKET_FRAMEWORK_DESC_MAX; i++) {
		if (g_descs[i].driver_desc &&
		    strcmp(g_descs[i].driver_desc->name, pdev->name) == 0)
			return &g_descs[i];
	}

return NULL;
}

/*
 * Verifies that the user has permissions to perform the requested mapping and
 * that the provided descriptor/range is of adequate size to hold the range to
 * be mapped.
 */
static bool gasket_mmap_has_permissions(struct gasket_dev *gasket_dev,
					struct vm_area_struct *vma,
					int bar_permissions)
{
	int requested_permissions;
	/* Always allow sysadmin to access. */
	if (capable(CAP_SYS_ADMIN))
		return true;

/* Never allow non-sysadmins to access to a dead device. */
	if (gasket_dev->status != GASKET_STATUS_ALIVE) {
		dev_dbg(gasket_dev->dev, "Device is dead.\n");
		return false;
	}

/* Make sure that no wrong flags are set. */
	requested_permissions =
		(vma->vm_flags & (VM_WRITE | VM_READ | VM_EXEC));
	if (requested_permissions & ~(bar_permissions)) {
		dev_dbg(gasket_dev->dev,
			"Attempting to map a region with requested permissions "
			"0x%x, but region has permissions 0x%x.\n",
			requested_permissions, bar_permissions);
		return false;
	}

/* Do not allow a non-owner to write. */
	if ((vma->vm_flags & VM_WRITE) &&
	    !gasket_owned_by_current_tgid(&gasket_dev->dev_info)) {
		dev_dbg(gasket_dev->dev,
			"Attempting to mmap a region for write without owning "
			"device.\n");
		return false;
	}

return true;
}

/*
 * Verifies that the input address is within the region allocated to coherent
 * buffer.
 */
static bool
gasket_is_coherent_region(const struct gasket_driver_desc *driver_desc,
			  ulong address)
{
	struct gasket_coherent_buffer_desc coh_buff_desc =
		driver_desc->coherent_buffer_description;

if (coh_buff_desc.permissions != GASKET_NOMAP) {
		if ((address >= coh_buff_desc.base) &&
		    (address < coh_buff_desc.base + coh_buff_desc.size)) {
			return true;
		}
	}
	return false;
}

static int gasket_get_bar_index(const struct gasket_dev *gasket_dev,
				ulong phys_addr)
{
	int i;
	const struct gasket_driver_desc *driver_desc;

driver_desc = gasket_dev->internal_desc->driver_desc;
	for (i = 0; i < GASKET_NUM_BARS; ++i) {
		struct gasket_bar_desc bar_desc =
			driver_desc->bar_descriptions[i];

if (bar_desc.permissions != GASKET_NOMAP) {
			if (phys_addr >= bar_desc.base &&
			    phys_addr < (bar_desc.base + bar_desc.size)) {
				return i;
			}
		}
	}
	/* If we haven't found the address by now, it is invalid. */
	return -EINVAL;
}

/*
 * Sets the actual bounds to map, given the device's mappable region.
 *
 * Given the device's mappable region, along with the user-requested mapping
 * start offset and length of the user region, determine how much of this
 * mappable region can be mapped into the user's region (start/end offsets),
 * and the physical offset (phys_offset) into the BAR where the mapping should
 * begin (either the VMA's or region lower bound).
 *
 * In other words, this calculates the overlap between the VMA
 * (bar_offset, requested_length) and the given gasket_mappable_region.
 *
 * Returns true if there's anything to map, and false otherwise.
 */
static bool
gasket_mm_get_mapping_addrs(const struct gasket_mappable_region *region,
			    ulong bar_offset, ulong requested_length,
			    struct gasket_mappable_region *mappable_region,
			    ulong *virt_offset)
{
	ulong range_start = region->start;
	ulong range_length = region->length_bytes;
	ulong range_end = range_start + range_length;

*virt_offset = 0;
	if (bar_offset + requested_length < range_start) {
		/*
		 * If the requested region is completely below the range,
		 * there is nothing to map.
		 */
		return false;
	} else if (bar_offset <= range_start) {
		/* If the bar offset is below this range's start
		 * but the requested length continues into it:
		 * 1) Only map starting from the beginning of this
		 *      range's phys. offset, so we don't map unmappable
		 *	memory.
		 * 2) The length of the virtual memory to not map is the
		 *	delta between the bar offset and the
		 *	mappable start (and since the mappable start is
		 *	bigger, start - req.)
		 * 3) The map length is the minimum of the mappable
		 *	requested length (requested_length - virt_offset)
		 *	and the actual mappable length of the range.
		 */
		mappable_region->start = range_start;
		*virt_offset = range_start - bar_offset;
		mappable_region->length_bytes =
			min(requested_length - *virt_offset, range_length);
		return true;
	} else if (bar_offset > range_start &&
		   bar_offset < range_end) {
		/*
		 * If the bar offset is within this range:
		 * 1) Map starting from the bar offset.
		 * 2) Because there is no forbidden memory between the
		 *	bar offset and the range start,
		 *	virt_offset is 0.
		 * 3) The map length is the minimum of the requested
		 *	length and the remaining length in the buffer
		 *	(range_end - bar_offset)
		 */
		mappable_region->start = bar_offset;
		*virt_offset = 0;
		mappable_region->length_bytes =
			min(requested_length, range_end - bar_offset);
		return true;
	}

/*
	 * If the requested [start] offset is above range_end,
	 * there's nothing to map.
	 */
	return false;
}

/*
 * Calculates the offset where the VMA range begins in its containing BAR.
 * The offset is written into bar_offset on success.
 * Returns zero on success, anything else on error.
 */
static int gasket_mm_vma_bar_offset(const struct gasket_dev *gasket_dev,
				    const struct vm_area_struct *vma,
				    ulong *bar_offset)
{
	ulong raw_offset;
	int bar_index;
	const struct gasket_driver_desc *driver_desc =
		gasket_dev->internal_desc->driver_desc;

raw_offset = (vma->vm_pgoff << PAGE_SHIFT) +
		driver_desc->legacy_mmap_address_offset;
	bar_index = gasket_get_bar_index(gasket_dev, raw_offset);
	if (bar_index < 0) {
		dev_err(gasket_dev->dev,
			"Unable to find matching bar for address 0x%lx\n",
			raw_offset);
		trace_gasket_mmap_exit(bar_index);
		return bar_index;
	}
	*bar_offset =
		raw_offset - driver_desc->bar_descriptions[bar_index].base;

return 0;
}

int gasket_mm_unmap_region(const struct gasket_dev *gasket_dev,
			   struct vm_area_struct *vma,
			   const struct gasket_mappable_region *map_region)
{
	ulong bar_offset;
	ulong virt_offset;
	struct gasket_mappable_region mappable_region;
	int ret;

if (map_region->length_bytes == 0)
		return 0;

ret = gasket_mm_vma_bar_offset(gasket_dev, vma, &bar_offset);
	if (ret)
		return ret;

if (!gasket_mm_get_mapping_addrs(map_region, bar_offset,
					 vma->vm_end - vma->vm_start,
					 &mappable_region, &virt_offset))
		return 1;

/*
	 * The length passed to zap_vma_ptes MUST BE A MULTIPLE OF
	 * PAGE_SIZE! Trust me. I have the scars.
	 *
	 * Next multiple of y: ceil_div(x, y) * y
	 */
	zap_vma_ptes(vma, vma->vm_start + virt_offset,
		     DIV_ROUND_UP(mappable_region.length_bytes, PAGE_SIZE) *
		     PAGE_SIZE);
	return 0;
}
EXPORT_SYMBOL(gasket_mm_unmap_region);

/* Maps a virtual address + range to a physical offset of a BAR. */
static enum do_map_region_status
do_map_region(const struct gasket_dev *gasket_dev, struct vm_area_struct *vma,
	      struct gasket_mappable_region *mappable_region)
{
	/* Maximum size of a single call to io_remap_pfn_range. */
	/* I pulled this number out of thin air. */
	const ulong max_chunk_size = 64 * 1024 * 1024;
	ulong chunk_size, mapped_bytes = 0;

const struct gasket_driver_desc *driver_desc =
		gasket_dev->internal_desc->driver_desc;

ulong bar_offset, virt_offset;
	struct gasket_mappable_region region_to_map;
	ulong phys_offset, map_length;
	ulong virt_base, phys_base;
	int bar_index, ret;

ret = gasket_mm_vma_bar_offset(gasket_dev, vma, &bar_offset);
	if (ret)
		return DO_MAP_REGION_INVALID;

if (!gasket_mm_get_mapping_addrs(mappable_region, bar_offset,
					 vma->vm_end - vma->vm_start,
					 &region_to_map, &virt_offset))
		return DO_MAP_REGION_INVALID;
	phys_offset = region_to_map.start;
	map_length = region_to_map.length_bytes;

virt_base = vma->vm_start + virt_offset;
	bar_index =
		gasket_get_bar_index(gasket_dev,
				     (vma->vm_pgoff << PAGE_SHIFT) +
				     driver_desc->legacy_mmap_address_offset);
	phys_base = gasket_dev->bar_data[bar_index].phys_base + phys_offset;
	while (mapped_bytes < map_length) {
		/*
		 * io_remap_pfn_range can take a while, so we chunk its
		 * calls and call cond_resched between each.
		 */
		chunk_size = min(max_chunk_size, map_length - mapped_bytes);

cond_resched();
		ret = io_remap_pfn_range(vma, virt_base + mapped_bytes,
					 (phys_base + mapped_bytes) >>
					 PAGE_SHIFT, chunk_size,
					 vma->vm_page_prot);
		if (ret) {
			dev_err(gasket_dev->dev,
				"Error remapping PFN range.\n");
			goto fail;
		}
		mapped_bytes += chunk_size;
	}

return DO_MAP_REGION_SUCCESS;

fail:
	/* Unmap the partial chunk we mapped. */
	mappable_region->length_bytes = mapped_bytes;
	if (gasket_mm_unmap_region(gasket_dev, vma, mappable_region))
		dev_err(gasket_dev->dev,
			"Error unmapping partial region 0x%lx (0x%lx bytes)\n",
			(ulong)virt_offset,
			(ulong)mapped_bytes);

return DO_MAP_REGION_FAILURE;
}

/* Map a region of coherent memory. */
static int gasket_mmap_coherent(struct gasket_dev *gasket_dev,
				struct vm_area_struct *vma)
{
	const struct gasket_driver_desc *driver_desc =
		gasket_dev->internal_desc->driver_desc;
	const ulong requested_length = vma->vm_end - vma->vm_start;
	int ret;
	ulong permissions;

if (requested_length == 0 || requested_length >
	    gasket_dev->coherent_buffer.length_bytes) {
		trace_gasket_mmap_exit(-EINVAL);
		return -EINVAL;
	}

permissions = driver_desc->coherent_buffer_description.permissions;
	if (!gasket_mmap_has_permissions(gasket_dev, vma, permissions)) {
		dev_err(gasket_dev->dev, "Permission checking failed.\n");
		trace_gasket_mmap_exit(-EPERM);
		return -EPERM;
	}

vma->vm_page_prot = pgprot_noncached(vma->vm_page_prot);
	vma->vm_pgoff = 0;
	ret = dma_mmap_coherent(gasket_dev->dma_dev, vma,
				gasket_dev->coherent_buffer.virt_base,
				gasket_dev->coherent_buffer.phys_base,
				requested_length);
	if (ret) {
		dev_err(gasket_dev->dev,
			"Error mmapping coherent buffer err=%d.\n", ret);
		trace_gasket_mmap_exit(ret);
		return ret;
	}

/* Record the user virtual to dma_address mapping that was
	 * created by the kernel.
	 */
	gasket_set_user_virt(gasket_dev, requested_length,
			     gasket_dev->coherent_buffer.phys_base,
			     vma->vm_start);
	return 0;
}

/* Map a device's BARs into user space. */
static int gasket_mmap(struct file *filp, struct vm_area_struct *vma)
{
	int i, ret;
	int bar_index;
	int has_mapped_anything = 0;
	ulong permissions;
	ulong raw_offset, vma_size;
	bool is_coherent_region;
	const struct gasket_driver_desc *driver_desc;
	struct gasket_dev *gasket_dev = (struct gasket_dev *)filp->private_data;
	const struct gasket_bar_desc *bar_desc;
	struct gasket_mappable_region *map_regions = NULL;
	int num_map_regions = 0;
	enum do_map_region_status map_status;

driver_desc = gasket_dev->internal_desc->driver_desc;

if (vma->vm_start & ~PAGE_MASK) {
		dev_err(gasket_dev->dev,
			"Base address not page-aligned: 0x%lx\n",
			vma->vm_start);
		trace_gasket_mmap_exit(-EINVAL);
		return -EINVAL;
	}

/* Calculate the offset of this range into physical mem. */
	raw_offset = (vma->vm_pgoff << PAGE_SHIFT) +
		driver_desc->legacy_mmap_address_offset;
	vma_size = vma->vm_end - vma->vm_start;
	trace_gasket_mmap_entry(gasket_dev->dev_info.name, raw_offset,
				vma_size);

/*
	 * Check if the raw offset is within a bar region. If not, check if it
	 * is a coherent region.
	 */
	bar_index = gasket_get_bar_index(gasket_dev, raw_offset);
	is_coherent_region = gasket_is_coherent_region(driver_desc, raw_offset);
	if (bar_index < 0 && !is_coherent_region) {
		dev_err(gasket_dev->dev,
			"Unable to find matching bar for address 0x%lx\n",
			raw_offset);
		trace_gasket_mmap_exit(bar_index);
		return bar_index;
	}
	if (bar_index > 0 && is_coherent_region) {
		dev_err(gasket_dev->dev,
			"double matching bar and coherent buffers for address "
			"0x%lx\n",
			raw_offset);
		trace_gasket_mmap_exit(bar_index);
		return -EINVAL;
	}

vma->vm_private_data = gasket_dev;

if (is_coherent_region)
		return gasket_mmap_coherent(gasket_dev, vma);

/* Everything in the rest of this function is for normal BAR mapping. */

/*
	 * Subtract the base of the bar from the raw offset to get the
	 * memory location within the bar to map.
	 */
	bar_desc = &driver_desc->bar_descriptions[bar_index];
	permissions = bar_desc->permissions;
	if (!gasket_mmap_has_permissions(gasket_dev, vma, permissions)) {
		dev_err(gasket_dev->dev, "Permission checking failed.\n");
		trace_gasket_mmap_exit(-EPERM);
		return -EPERM;
	}

if (driver_desc->get_mappable_regions_cb) {
		ret = driver_desc->get_mappable_regions_cb(gasket_dev,
							   bar_index,
							   &map_regions,
							   &num_map_regions);
		if (ret)
			return ret;
	} else {
		if (!gasket_mmap_has_permissions(gasket_dev, vma,
						 bar_desc->permissions)) {
			dev_err(gasket_dev->dev,
				"Permission checking failed.\n");
			trace_gasket_mmap_exit(-EPERM);
			return -EPERM;
		}
		num_map_regions = bar_desc->num_mappable_regions;
		map_regions = kcalloc(num_map_regions,
				      sizeof(*bar_desc->mappable_regions),
				      GFP_KERNEL);
		if (map_regions) {
			memcpy(map_regions, bar_desc->mappable_regions,
			       num_map_regions *
					sizeof(*bar_desc->mappable_regions));
		}
	}

if (!map_regions || num_map_regions == 0) {
		dev_err(gasket_dev->dev, "No mappable regions returned!\n");
		return -EINVAL;
	}

/* Marks the VMA's pages as uncacheable. */
	vma->vm_page_prot = pgprot_noncached(vma->vm_page_prot);
	for (i = 0; i < num_map_regions; i++) {
		map_status = do_map_region(gasket_dev, vma, &map_regions[i]);
		/* Try the next region if this one was not mappable. */
		if (map_status == DO_MAP_REGION_INVALID)
			continue;
		if (map_status == DO_MAP_REGION_FAILURE) {
			ret = -ENOMEM;
			goto fail;
		}

has_mapped_anything = 1;
	}

kfree(map_regions);

/* If we could not map any memory, the request was invalid. */
	if (!has_mapped_anything) {
		dev_err(gasket_dev->dev,
			"Map request did not contain a valid region.\n");
		trace_gasket_mmap_exit(-EINVAL);
		return -EINVAL;
	}

trace_gasket_mmap_exit(0);
	return 0;

fail:
	/* Need to unmap any mapped ranges. */
	num_map_regions = i;
	for (i = 0; i < num_map_regions; i++)
		if (gasket_mm_unmap_region(gasket_dev, vma,
					   &bar_desc->mappable_regions[i]))
			dev_err(gasket_dev->dev, "Error unmapping range %d.\n",
				i);
	kfree(map_regions);

return ret;
}

/*
 * Open the char device file.
 *
 * If the open is for writing, and the device is not owned, this process becomes
 * the owner.  If the open is for writing and the device is already owned by
 * some other process, it is an error.  If this process is the owner, increment
 * the open count.
 *
 * Returns 0 if successful, a negative error number otherwise.
 */
static int gasket_open(struct inode *inode, struct file *filp)
{
	int ret;
	struct gasket_dev *gasket_dev;
	const struct gasket_driver_desc *driver_desc;
	struct gasket_ownership *ownership;
	char task_name[TASK_COMM_LEN];
	struct gasket_cdev_info *dev_info =
	    container_of(inode->i_cdev, struct gasket_cdev_info, cdev);
	struct pid_namespace *pid_ns = task_active_pid_ns(current);
	bool is_root = ns_capable(pid_ns->user_ns, CAP_SYS_ADMIN);

gasket_dev = dev_info->gasket_dev_ptr;
	driver_desc = gasket_dev->internal_desc->driver_desc;
	ownership = &dev_info->ownership;
	get_task_comm(task_name, current);
	filp->private_data = gasket_dev;
	inode->i_size = 0;

dev_dbg(gasket_dev->dev,
		"Attempting to open with tgid %u (%s) (f_mode: 0%03o, "
		"fmode_write: %d is_root: %u)\n",
		current->tgid, task_name, filp->f_mode,
		(filp->f_mode & FMODE_WRITE), is_root);

/* Always allow non-writing accesses. */
	if (!(filp->f_mode & FMODE_WRITE)) {
		dev_dbg(gasket_dev->dev, "Allowing read-only opening.\n");
		return 0;
	}

mutex_lock(&gasket_dev->mutex);

dev_dbg(gasket_dev->dev,
		"Current owner open count (owning tgid %u): %d.\n",
		ownership->owner, ownership->write_open_count);

/* Opening a node owned by another TGID is an error (unless root) */
	if (ownership->is_owned && ownership->owner != current->tgid &&
	    !is_root) {
		dev_err(gasket_dev->dev,
			"Process %u is opening a node held by %u.\n",
			current->tgid, ownership->owner);
		mutex_unlock(&gasket_dev->mutex);
		return -EPERM;
	}

/* If the node is not owned, assign it to the current TGID. */
	if (!ownership->is_owned) {
		ret = gasket_check_and_invoke_callback_nolock(gasket_dev,
							      driver_desc->device_open_cb);
		if (ret) {
			dev_err(gasket_dev->dev,
				"Error in device open cb: %d\n", ret);
			mutex_unlock(&gasket_dev->mutex);
			return ret;
		}
		ownership->is_owned = 1;
		ownership->owner = current->tgid;
		dev_dbg(gasket_dev->dev, "Device owner is now tgid %u\n",
			ownership->owner);
	}

ownership->write_open_count++;

dev_dbg(gasket_dev->dev, "New open count (owning tgid %u): %d\n",
		ownership->owner, ownership->write_open_count);

mutex_unlock(&gasket_dev->mutex);
	return 0;
}

/*
 * Called on a close of the device file.  If this process is the owner,
 * decrement the open count.  On last close by the owner, free up buffers and
 * eventfd contexts, and release ownership.
 *
 * Returns 0 if successful, a negative error number otherwise.
 */
static int gasket_release(struct inode *inode, struct file *file)
{
	int i;
	struct gasket_dev *gasket_dev;
	struct gasket_ownership *ownership;
	const struct gasket_driver_desc *driver_desc;
	char task_name[TASK_COMM_LEN];
	struct gasket_cdev_info *dev_info =
		container_of(inode->i_cdev, struct gasket_cdev_info, cdev);
	struct pid_namespace *pid_ns = task_active_pid_ns(current);
	bool is_root = ns_capable(pid_ns->user_ns, CAP_SYS_ADMIN);

gasket_dev = dev_info->gasket_dev_ptr;
	driver_desc = gasket_dev->internal_desc->driver_desc;
	ownership = &dev_info->ownership;
	get_task_comm(task_name, current);
	mutex_lock(&gasket_dev->mutex);

dev_dbg(gasket_dev->dev,
		"Releasing device node. Call origin: tgid %u (%s) "
		"(f_mode: 0%03o, fmode_write: %d, is_root: %u)\n",
		current->tgid, task_name, file->f_mode,
		(file->f_mode & FMODE_WRITE), is_root);
	dev_dbg(gasket_dev->dev, "Current open count (owning tgid %u): %d\n",
		ownership->owner, ownership->write_open_count);

if (file->f_mode & FMODE_WRITE) {
		ownership->write_open_count--;
		if (ownership->write_open_count == 0) {
			dev_dbg(gasket_dev->dev, "Device is now free\n");
			ownership->is_owned = 0;
			ownership->owner = 0;

/* Forces chip reset before we unmap the page tables. */
			driver_desc->device_reset_cb(gasket_dev);

for (i = 0; i < driver_desc->num_page_tables; ++i) {
				gasket_page_table_unmap_all(gasket_dev->page_table[i]);
				gasket_page_table_garbage_collect(gasket_dev->page_table[i]);
				gasket_free_coherent_memory_all(gasket_dev, i);
			}

/* Closes device, enters power save. */
			gasket_check_and_invoke_callback_nolock(gasket_dev,
								driver_desc->device_close_cb);
		}
	}

dev_dbg(gasket_dev->dev, "New open count (owning tgid %u): %d\n",
		ownership->owner, ownership->write_open_count);
	mutex_unlock(&gasket_dev->mutex);
	return 0;
}

/*
 * Gasket ioctl dispatch function.
 *
 * Check if the ioctl is a generic ioctl. If not, pass the ioctl to the
 * ioctl_handler_cb registered in the driver description.
 * If the ioctl is a generic ioctl, pass it to gasket_ioctl_handler.
 */
static long gasket_ioctl(struct file *filp, uint cmd, ulong arg)
{
	struct gasket_dev *gasket_dev;
	const struct gasket_driver_desc *driver_desc;
	void __user *argp = (void __user *)arg;
	char path[256];

gasket_dev = (struct gasket_dev *)filp->private_data;
	driver_desc = gasket_dev->internal_desc->driver_desc;
	if (!driver_desc) {
		dev_dbg(gasket_dev->dev,
			"Unable to find device descriptor for file %s\n",
			d_path(&filp->f_path, path, 256));
		return -ENODEV;
	}

if (!gasket_is_supported_ioctl(cmd)) {
		/*
		 * The ioctl handler is not a standard Gasket callback, since
		 * it requires different arguments. This means we can't use
		 * check_and_invoke_callback.
		 */
		if (driver_desc->ioctl_handler_cb)
			return driver_desc->ioctl_handler_cb(filp, cmd, argp);

dev_dbg(gasket_dev->dev, "Received unknown ioctl 0x%x\n", cmd);
		return -EINVAL;
	}

return gasket_handle_ioctl(filp, cmd, argp);
}

/* File operations for all Gasket devices. */
static const struct file_operations gasket_file_ops = {
	.owner = THIS_MODULE,
	.llseek = no_llseek,
	.mmap = gasket_mmap,
	.open = gasket_open,
	.release = gasket_release,
	.unlocked_ioctl = gasket_ioctl,
	.compat_ioctl = gasket_ioctl,
};

/* Perform final init and marks the device as active. */
int gasket_enable_device(struct gasket_dev *gasket_dev)
{
	int tbl_idx;
	int ret;
	const struct gasket_driver_desc *driver_desc =
		gasket_dev->internal_desc->driver_desc;

dev_dbg(gasket_dev->dev, "enabling device\n");
	ret = gasket_interrupt_init(gasket_dev);
	if (ret) {
		dev_err(gasket_dev->dev,
			"Critical failure to allocate interrupts: %d\n", ret);
		gasket_interrupt_cleanup(gasket_dev);
		return ret;
	}

for (tbl_idx = 0; tbl_idx < driver_desc->num_page_tables; tbl_idx++) {
		dev_dbg(gasket_dev->dev, "Initializing page table %d.\n",
			tbl_idx);
		ret = gasket_page_table_init(&gasket_dev->page_table[tbl_idx],
					     &gasket_dev->bar_data[driver_desc->page_table_bar_index],
					     &driver_desc->page_table_configs[tbl_idx],
					     gasket_dev->dev,
					     gasket_dev->pci_dev);
		if (ret) {
			dev_err(gasket_dev->dev,
				"Couldn't init page table %d: %d\n",
				tbl_idx, ret);
			return ret;
		}
		/*
		 * Make sure that the page table is clear and set to simple
		 * addresses.
		 */
		gasket_page_table_reset(gasket_dev->page_table[tbl_idx]);
	}

/*
	 * hardware_revision_cb returns a positive integer (the rev) if
	 * successful.)
	 */
	ret = check_and_invoke_callback(gasket_dev,
					driver_desc->hardware_revision_cb);
	if (ret < 0) {
		dev_err(gasket_dev->dev,
			"Error getting hardware revision: %d\n", ret);
		return ret;
	}
	gasket_dev->hardware_revision = ret;

/* device_status_cb returns a device status, not an error code. */
	gasket_dev->status = gasket_get_hw_status(gasket_dev);
	if (gasket_dev->status == GASKET_STATUS_DEAD)
		dev_err(gasket_dev->dev, "Device reported as unhealthy.\n");

ret = gasket_add_cdev(&gasket_dev->dev_info, &gasket_file_ops,
			      driver_desc->module);
	if (ret)
		return ret;

return 0;
}
EXPORT_SYMBOL(gasket_enable_device);

static int __gasket_add_device(struct device *parent_dev,
			       struct gasket_internal_desc *internal_desc,
			       struct gasket_dev **gasket_devp)
{
	int ret;
	struct gasket_dev *gasket_dev;
	const struct gasket_driver_desc *driver_desc =
	    internal_desc->driver_desc;

ret = gasket_alloc_dev(internal_desc, parent_dev, &gasket_dev);
	if (ret)
		return ret;
	if (IS_ERR(gasket_dev->dev_info.device)) {
		dev_err(parent_dev, "Cannot create %s device %s [ret = %ld]\n",
			driver_desc->name, gasket_dev->dev_info.name,
			PTR_ERR(gasket_dev->dev_info.device));
		ret = -ENODEV;
		goto free_gasket_dev;
	}

ret = gasket_sysfs_create_mapping(gasket_dev->dev_info.device,
					  gasket_dev);
	if (ret)
		goto remove_device;

ret = gasket_sysfs_create_entries(gasket_dev->dev_info.device,
					  gasket_sysfs_generic_attrs);
	if (ret)
		goto remove_sysfs_mapping;

*gasket_devp = gasket_dev;
	return 0;

remove_sysfs_mapping:
	gasket_sysfs_remove_mapping(gasket_dev->dev_info.device);
remove_device:
	device_destroy(internal_desc->class, gasket_dev->dev_info.devt);
free_gasket_dev:
	gasket_free_dev(gasket_dev);
	return ret;
}

static void __gasket_remove_device(struct gasket_internal_desc *internal_desc,
				   struct gasket_dev *gasket_dev)
{
	gasket_sysfs_remove_mapping(gasket_dev->dev_info.device);
	device_destroy(internal_desc->class, gasket_dev->dev_info.devt);
	gasket_free_dev(gasket_dev);
}

/*
 * Add PCI gasket device.
 *
 * Called by Gasket device probe function.
 * Allocates device metadata and maps device memory.  The device driver must
 * call gasket_enable_device after driver init is complete to place the device
 * in active use.
 */
int gasket_pci_add_device(struct pci_dev *pci_dev,
			  struct gasket_dev **gasket_devp)
{
	int ret;
	struct gasket_internal_desc *internal_desc;
	struct gasket_dev *gasket_dev;
	struct device *parent;

dev_dbg(&pci_dev->dev, "add PCI gasket device\n");

mutex_lock(&g_mutex);
	internal_desc = lookup_pci_internal_desc(pci_dev);
	mutex_unlock(&g_mutex);
	if (!internal_desc) {
		dev_err(&pci_dev->dev,
			"PCI add device called for unknown driver type\n");
		return -ENODEV;
	}

parent = &pci_dev->dev;
	ret = __gasket_add_device(parent, internal_desc, &gasket_dev);
	if (ret)
		return ret;

gasket_dev->pci_dev = pci_dev;
	ret = gasket_setup_pci(pci_dev, gasket_dev);
	if (ret)
		goto cleanup_pci;

/*
	 * Once we've created the mapping structures successfully, attempt to
	 * create a symlink to the pci directory of this object.
	 */
	ret = sysfs_create_link(&gasket_dev->dev_info.device->kobj,
				&pci_dev->dev.kobj, dev_name(&pci_dev->dev));
	if (ret) {
		dev_err(gasket_dev->dev,
			"Cannot create sysfs pci link: %d\n", ret);
		goto cleanup_pci;
	}

*gasket_devp = gasket_dev;
	return 0;

cleanup_pci:
	gasket_cleanup_pci(gasket_dev);
	__gasket_remove_device(internal_desc, gasket_dev);
	return ret;
}
EXPORT_SYMBOL(gasket_pci_add_device);

/* Remove a PCI gasket device. */
void gasket_pci_remove_device(struct pci_dev *pci_dev)
{
	int i;
	struct gasket_internal_desc *internal_desc;
	struct gasket_dev *gasket_dev = NULL;
	/* Find the device desc. */
	mutex_lock(&g_mutex);
	internal_desc = lookup_pci_internal_desc(pci_dev);
	if (!internal_desc) {
		mutex_unlock(&g_mutex);
		return;
	}
	mutex_unlock(&g_mutex);

/* Now find the specific device */
	mutex_lock(&internal_desc->mutex);
	for (i = 0; i < GASKET_DEV_MAX; i++) {
		if (internal_desc->devs[i] &&
		    internal_desc->devs[i]->pci_dev == pci_dev) {
			gasket_dev = internal_desc->devs[i];
			break;
		}
	}
	mutex_unlock(&internal_desc->mutex);

if (!gasket_dev)
		return;

dev_dbg(gasket_dev->dev, "remove %s PCI gasket device\n",
		internal_desc->driver_desc->name);

gasket_cleanup_pci(gasket_dev);
	__gasket_remove_device(internal_desc, gasket_dev);
}
EXPORT_SYMBOL(gasket_pci_remove_device);

/* Add platform gasket device. Called by Gasket device probe function. */
int gasket_platform_add_device(struct platform_device *pdev,
			       struct gasket_dev **gasket_devp)
{
	int ret;
	struct gasket_internal_desc *internal_desc;
	struct gasket_dev *gasket_dev;
	struct device *parent;

dev_dbg(&pdev->dev, "add platform gasket device\n");

mutex_lock(&g_mutex);
	internal_desc = lookup_platform_internal_desc(pdev);
	mutex_unlock(&g_mutex);
	if (!internal_desc) {
		dev_err(&pdev->dev,
			"%s called for unknown driver type\n", __func__);
		return -ENODEV;
	}

parent = &pdev->dev;
	ret = __gasket_add_device(parent, internal_desc, &gasket_dev);
	if (ret)
		return ret;

gasket_dev->platform_dev = pdev;
	*gasket_devp = gasket_dev;
	return 0;
}
EXPORT_SYMBOL(gasket_platform_add_device);

/* Remove a platform gasket device. */
void gasket_platform_remove_device(struct platform_device *pdev)
{
	int i;
	struct gasket_internal_desc *internal_desc;
	struct gasket_dev *gasket_dev = NULL;

/* Find the device desc. */
	mutex_lock(&g_mutex);
	internal_desc = lookup_platform_internal_desc(pdev);
	mutex_unlock(&g_mutex);
	if (!internal_desc)
		return;

/* Now find the specific device */
	mutex_lock(&internal_desc->mutex);
	for (i = 0; i < GASKET_DEV_MAX; i++) {
		if (internal_desc->devs[i] &&
		    internal_desc->devs[i]->platform_dev == pdev) {
			gasket_dev = internal_desc->devs[i];
			break;
		}
	}
	mutex_unlock(&internal_desc->mutex);

if (!gasket_dev)
		return;

dev_dbg(gasket_dev->dev, "remove %s platform gasket device\n",
		internal_desc->driver_desc->name);

__gasket_remove_device(internal_desc, gasket_dev);
}
EXPORT_SYMBOL(gasket_platform_remove_device);

void gasket_set_dma_device(struct gasket_dev *gasket_dev,
			   struct device *dma_dev)
{
	put_device(gasket_dev->dma_dev);
	gasket_dev->dma_dev = get_device(dma_dev);
}
EXPORT_SYMBOL(gasket_set_dma_device);

/**
 * Lookup a name by number in a num_name table.
 * @num: Number to lookup.
 * @table: Array of num_name structures, the table for the lookup.
 *
 * Description: Searches for num in the table.  If found, the
 *		corresponding name is returned; otherwise NULL
 *		is returned.
 *
 *		The table must have a NULL name pointer at the end.
 */
const char *gasket_num_name_lookup(uint num,
				   const struct gasket_num_name *table)
{
	uint i = 0;

while (table[i].snn_name) {
		if (num == table[i].snn_num)
			break;
		++i;
	}

return table[i].snn_name;
}
EXPORT_SYMBOL(gasket_num_name_lookup);

int gasket_reset(struct gasket_dev *gasket_dev)
{
	int ret;

mutex_lock(&gasket_dev->mutex);
	ret = gasket_reset_nolock(gasket_dev);
	mutex_unlock(&gasket_dev->mutex);
	return ret;
}
EXPORT_SYMBOL(gasket_reset);

int gasket_reset_nolock(struct gasket_dev *gasket_dev)
{
	int ret;
	int i;
	const struct gasket_driver_desc *driver_desc;

driver_desc = gasket_dev->internal_desc->driver_desc;
	if (!driver_desc->device_reset_cb)
		return 0;

ret = driver_desc->device_reset_cb(gasket_dev);
	if (ret) {
		dev_dbg(gasket_dev->dev, "Device reset cb returned %d.\n",
			ret);
		return ret;
	}

/* Reinitialize the page tables and interrupt framework. */
	for (i = 0; i < driver_desc->num_page_tables; ++i)
		gasket_page_table_reset(gasket_dev->page_table[i]);

ret = gasket_interrupt_reinit(gasket_dev);
	if (ret) {
		dev_dbg(gasket_dev->dev, "Unable to reinit interrupts: %d.\n",
			ret);
		return ret;
	}

/* Get current device health. */
	gasket_dev->status = gasket_get_hw_status(gasket_dev);
	if (gasket_dev->status == GASKET_STATUS_DEAD) {
		dev_dbg(gasket_dev->dev, "Device reported as dead.\n");
		return -EINVAL;
	}

return 0;
}
EXPORT_SYMBOL(gasket_reset_nolock);

gasket_ioctl_permissions_cb_t
gasket_get_ioctl_permissions_cb(struct gasket_dev *gasket_dev)
{
	return gasket_dev->internal_desc->driver_desc->ioctl_permissions_cb;
}
EXPORT_SYMBOL(gasket_get_ioctl_permissions_cb);

/* Get the driver structure for a given gasket_dev.
 * @dev: pointer to gasket_dev, implementing the requested driver.
 */
const struct gasket_driver_desc *gasket_get_driver_desc(struct gasket_dev *dev)
{
	return dev->internal_desc->driver_desc;
}

/* Get the device structure for a given gasket_dev.
 * @dev: pointer to gasket_dev, implementing the requested driver.
 */
struct device *gasket_get_device(struct gasket_dev *dev)
{
	return dev->dev;
}

/**
 * Asynchronously waits on device.
 * @gasket_dev: Device struct.
 * @bar: Bar
 * @offset: Register offset
 * @mask: Register mask
 * @val: Expected value
 * @max_retries: number of sleep periods
 * @delay_ms: Timeout in milliseconds
 *
 * Description: Busy waits for a specific combination of bits to be set on a
 * Gasket register.
 **/
int gasket_wait_with_reschedule(struct gasket_dev *gasket_dev, int bar,
				u64 offset, u64 mask, u64 val,
				uint max_retries, u64 delay_ms)
{
	uint retries = 0;
	u64 tmp;

while (retries < max_retries) {
		tmp = gasket_dev_read_64(gasket_dev, bar, offset);
		if ((tmp & mask) == val)
			return 0;
		msleep(delay_ms);
		retries++;
	}
	dev_dbg(gasket_dev->dev, "%s timeout: reg %llx timeout (%llu ms)\n",
		__func__, offset, max_retries * delay_ms);
	return -ETIMEDOUT;
}
EXPORT_SYMBOL(gasket_wait_with_reschedule);

/* See gasket_core.h for description. */
int gasket_register_device(const struct gasket_driver_desc *driver_desc)
{
	int i, ret;
	int desc_idx = -1;
	struct gasket_internal_desc *internal;

pr_debug("Loading %s driver version %s\n", driver_desc->name,
		 driver_desc->driver_version);
	/* Check for duplicates and find a free slot. */
	mutex_lock(&g_mutex);

for (i = 0; i < GASKET_FRAMEWORK_DESC_MAX; i++) {
		if (g_descs[i].driver_desc == driver_desc) {
			pr_err("%s driver already loaded/registered\n",
			       driver_desc->name);
			mutex_unlock(&g_mutex);
			return -EBUSY;
		}
	}

/* This and the above loop could be combined, but this reads easier. */
	for (i = 0; i < GASKET_FRAMEWORK_DESC_MAX; i++) {
		if (!g_descs[i].driver_desc) {
			g_descs[i].driver_desc = driver_desc;
			desc_idx = i;
			break;
		}
	}
	mutex_unlock(&g_mutex);

if (desc_idx == -1) {
		pr_err("too many drivers loaded, max %d\n",
		       GASKET_FRAMEWORK_DESC_MAX);
		return -EBUSY;
	}

internal = &g_descs[desc_idx];
	mutex_init(&internal->mutex);
	memset(internal->devs, 0, sizeof(struct gasket_dev *) * GASKET_DEV_MAX);
	internal->class =
		class_create(driver_desc->module, driver_desc->name);

if (IS_ERR(internal->class)) {
		pr_err("Cannot register %s class [ret=%ld]\n",
		       driver_desc->name, PTR_ERR(internal->class));
		ret = PTR_ERR(internal->class);
		goto unregister_gasket_driver;
	}

ret = register_chrdev_region(MKDEV(driver_desc->major,
					   driver_desc->minor), GASKET_DEV_MAX,
				     driver_desc->name);
	if (ret) {
		pr_err("cannot register %s char driver [ret=%d]\n",
		       driver_desc->name, ret);
		goto destroy_class;
	}

return 0;

destroy_class:
	class_destroy(internal->class);

unregister_gasket_driver:
	mutex_lock(&g_mutex);
	g_descs[desc_idx].driver_desc = NULL;
	mutex_unlock(&g_mutex);
	return ret;
}
EXPORT_SYMBOL(gasket_register_device);

/* See gasket_core.h for description. */
void gasket_unregister_device(const struct gasket_driver_desc *driver_desc)
{
	int i, desc_idx;
	struct gasket_internal_desc *internal_desc = NULL;

mutex_lock(&g_mutex);
	for (i = 0; i < GASKET_FRAMEWORK_DESC_MAX; i++) {
		if (g_descs[i].driver_desc == driver_desc) {
			internal_desc = &g_descs[i];
			desc_idx = i;
			break;
		}
	}

if (!internal_desc) {
		mutex_unlock(&g_mutex);
		pr_err("request to unregister unknown desc: %s, %d:%d\n",
		       driver_desc->name, driver_desc->major,
		       driver_desc->minor);
		return;
	}

unregister_chrdev_region(MKDEV(driver_desc->major, driver_desc->minor),
				 GASKET_DEV_MAX);

class_destroy(internal_desc->class);

/* Finally, effectively "remove" the driver. */
	g_descs[desc_idx].driver_desc = NULL;
	mutex_unlock(&g_mutex);

pr_debug("removed %s driver\n", driver_desc->name);
}
EXPORT_SYMBOL(gasket_unregister_device);

static int __init gasket_init(void)
{
	int i;

mutex_lock(&g_mutex);
	for (i = 0; i < GASKET_FRAMEWORK_DESC_MAX; i++) {
		g_descs[i].driver_desc = NULL;
		mutex_init(&g_descs[i].mutex);
	}

gasket_sysfs_init();

mutex_unlock(&g_mutex);
	return 0;
}

MODULE_DESCRIPTION("Google Gasket driver framework");
MODULE_VERSION(GASKET_FRAMEWORK_VERSION);
MODULE_LICENSE("GPL v2");
MODULE_AUTHOR("Rob Springer <rspringer@google.com>");
module_init(gasket_init);
07070100000015000081A40000000000000000000000016217DF4F00004F0D000000000000000000000000000000000000002700000000gasket-driver-1.0.18/src/gasket_core.h/* SPDX-License-Identifier: GPL-2.0 */
/*
 * Gasket generic driver. Defines the set of data types and functions necessary
 * to define a driver using the Gasket generic driver framework.
 *
 * Copyright (C) 2018 Google, Inc.
 */
#ifndef __GASKET_CORE_H__
#define __GASKET_CORE_H__

#include <linux/cdev.h>
#include <linux/compiler.h>
#include <linux/device.h>
#include <linux/init.h>
#include <linux/module.h>
#include <linux/pci.h>
#include <linux/platform_device.h>
#include <linux/sched.h>
#include <linux/slab.h>

#include "gasket_constants.h"

/**
 * struct gasket_num_name - Map numbers to names.
 * @ein_num: Number.
 * @ein_name: Name associated with the number, a char pointer.
 *
 * This structure maps numbers to names. It is used to provide printable enum
 * names, e.g {0, "DEAD"} or {1, "ALIVE"}.
 */
struct gasket_num_name {
	uint snn_num;
	const char *snn_name;
};

/*
 * Register location for packed interrupts.
 * Each value indicates the location of an interrupt field (in units of
 * gasket_driver_desc->interrupt_pack_width) within the containing register.
 * In other words, this indicates the shift to use when creating a mask to
 * extract/set bits within a register for a given interrupt.
 */
enum gasket_interrupt_packing {
	PACK_0 = 0,
	PACK_1 = 1,
	PACK_2 = 2,
	PACK_3 = 3,
	UNPACKED = 4,
};

/* Type of the interrupt supported by the device. */
enum gasket_interrupt_type {
	PCI_MSIX = 0,
	DEVICE_MANAGED = 1, /* Managed externally in device driver */
};

/*
 * Used to describe a Gasket interrupt. Contains an interrupt index, a register,
 * and packing data for that interrupt. The register and packing data
 * fields are relevant only for PCI_MSIX interrupt type and can be
 * set to 0 for everything else.
 */
struct gasket_interrupt_desc {
	/* Device-wide interrupt index/number. */
	int index;
	/* The register offset controlling this interrupt. */
	u64 reg;
	/* The location of this interrupt inside register reg, if packed. */
	int packing;
};

/*
 * This enum is used to identify memory regions being part of the physical
 * memory that belongs to a device.
 */
enum mappable_area_type {
	PCI_BAR = 0, /* Default */
	BUS_REGION,  /* For SYSBUS devices, i.e. AXI etc... */
	COHERENT_MEMORY
};

/*
 * Metadata for each BAR mapping.
 * This struct is used so as to track PCI memory, I/O space, AXI and coherent
 * memory area... i.e. memory objects which can be referenced in the device's
 * mmap function.
 */
struct gasket_bar_data {
	/* Virtual base address. */
	u8 __iomem *virt_base;

/* Physical base address. */
	ulong phys_base;

/* Length of the mapping. */
	ulong length_bytes;

/* Type of mappable area */
	enum mappable_area_type type;
};

/* Maintains device open ownership data. */
struct gasket_ownership {
	/* 1 if the device is owned, 0 otherwise. */
	int is_owned;

/* TGID of the owner. */
	pid_t owner;

/* Count of current device opens in write mode. */
	int write_open_count;
};

/* Page table modes of operation. */
enum gasket_page_table_mode {
	/* The page table is partitionable as normal, all simple by default. */
	GASKET_PAGE_TABLE_MODE_NORMAL,

/* All entries are always simple. */
	GASKET_PAGE_TABLE_MODE_SIMPLE,

/* All entries are always extended. No extended bit is used. */
	GASKET_PAGE_TABLE_MODE_EXTENDED,
};

/* Page table configuration. One per table. */
struct gasket_page_table_config {
	/* The identifier/index of this page table. */
	int id;

/* The operation mode of this page table. */
	enum gasket_page_table_mode mode;

/* Total (first-level) entries in this page table. */
	ulong total_entries;

/* Base register for the page table. */
	int base_reg;

/*
	 * Register containing the extended page table. This value is unused in
	 * GASKET_PAGE_TABLE_MODE_SIMPLE and GASKET_PAGE_TABLE_MODE_EXTENDED
	 * modes.
	 */
	int extended_reg;

/* The bit index indicating whether a PT entry is extended. */
	int extended_bit;
};

/* Maintains information about a device node. */
struct gasket_cdev_info {
	/* The internal name of this device. */
	char name[GASKET_NAME_MAX];

/* Device number. */
	dev_t devt;

/* Kernel-internal device structure. */
	struct device *device;

/* Character device for real. */
	struct cdev cdev;

/* Flag indicating if cdev_add has been called for the devices. */
	int cdev_added;

/* Pointer to the overall gasket_dev struct for this device. */
	struct gasket_dev *gasket_dev_ptr;

/* Ownership data for the device in question. */
	struct gasket_ownership ownership;
};

/* Describes the offset and length of mmapable device BAR regions. */
struct gasket_mappable_region {
	u64 start;
	u64 length_bytes;
};

/* Describe the offset, size, and permissions for a device bar. */
struct gasket_bar_desc {
	/*
	 * The size of each PCI BAR range, in bytes. If a value is 0, that BAR
	 * will not be mapped into kernel space at all.
	 * For devices with 64 bit BARs, only elements 0, 2, and 4 should be
	 * populated, and 1, 3, and 5 should be set to 0.
	 * For example, for a device mapping 1M in each of the first two 64-bit
	 * BARs, this field would be set as { 0x100000, 0, 0x100000, 0, 0, 0 }
	 * (one number per bar_desc struct.)
	 */
	u64 size;
	/* The permissions for this bar. (Should be VM_WRITE/VM_READ/VM_EXEC,
	 * and can be or'd.) If set to GASKET_NOMAP, the bar will
	 * not be used for mmapping.
	 */
	ulong permissions;
	/* The memory address corresponding to the base of this bar, if used. */
	u64 base;
	/* The number of mappable regions in this bar. */
	int num_mappable_regions;

/* The mappable subregions of this bar. */
	const struct gasket_mappable_region *mappable_regions;

/* Type of mappable area */
	enum mappable_area_type type;
};

/* Describes the offset, size, and permissions for a coherent buffer. */
struct gasket_coherent_buffer_desc {
	/* The size of the coherent buffer. */
	u64 size;

/* The permissions for this bar. (Should be VM_WRITE/VM_READ/VM_EXEC,
	 * and can be or'd.) If set to GASKET_NOMAP, the bar will
	 * not be used for mmaping.
	 */
	ulong permissions;

/* device side address. */
	u64 base;
};

/* Coherent buffer structure. */
struct gasket_coherent_buffer {
	/* Virtual base address. */
	u8 __iomem *virt_base;

/* Physical base address. */
	dma_addr_t phys_base;

/* Length of the mapping. */
	ulong length_bytes;
};

/* Description of Gasket-specific permissions in the mmap field. */
enum gasket_mapping_options { GASKET_NOMAP = 0 };

/* This struct represents an undefined bar that should never be mapped. */
#define GASKET_UNUSED_BAR                                                      \
	{                                                                      \
		0, GASKET_NOMAP, 0, 0, NULL, 0                                 \
	}

/* Internal data for a Gasket device. See gasket_core.c for more information. */
struct gasket_internal_desc;

#define MAX_NUM_COHERENT_PAGES 16

/*
 * Device data for Gasket device instances.
 *
 * This structure contains the data required to manage a Gasket device.
 */
struct gasket_dev {
	/* Pointer to the internal driver description for this device. */
	struct gasket_internal_desc *internal_desc;

/* Device info */
	struct device *dev;

/* DMA device to use, may be same as above or a parent */
	struct device *dma_dev;

/* PCI device pointer for PCI devices */
	struct pci_dev *pci_dev;

/* Platform device pointer for platform devices */
	struct platform_device *platform_dev;

/* This device's index into internal_desc->devs. */
	int dev_idx;

/* The name of this device, as reported by the kernel. */
	char kobj_name[GASKET_NAME_MAX];

/* Virtual address of mapped BAR memory range. */
	struct gasket_bar_data bar_data[GASKET_NUM_BARS];

/* Coherent buffer. */
	struct gasket_coherent_buffer coherent_buffer;

/* Number of page tables for this device. */
	int num_page_tables;

/* Address translations. Page tables have a private implementation. */
	struct gasket_page_table *page_table[GASKET_MAX_NUM_PAGE_TABLES];

/* Interrupt data for this device. */
	struct gasket_interrupt_data *interrupt_data;

/* Status for this device - GASKET_STATUS_ALIVE or _DEAD. */
	uint status;

/* Number of times this device has been reset. */
	uint reset_count;

/* Dev information for the cdev node. */
	struct gasket_cdev_info dev_info;

/* Hardware revision value for this device. */
	int hardware_revision;

/* Protects access to per-device data (i.e. this structure). */
	struct mutex mutex;

/* cdev hash tracking/membership structure, Accel and legacy. */
	/* Unused until Accel is upstreamed. */
	struct hlist_node hlist_node;
	struct hlist_node legacy_hlist_node;
};

/* Type of the ioctl handler callback. */
typedef long (*gasket_ioctl_handler_cb_t)(struct file *file, uint cmd,
					  void __user *argp);
/* Type of the ioctl permissions check callback. See below. */
typedef int (*gasket_ioctl_permissions_cb_t)(struct file *filp, uint cmd,
					     void __user *argp);

/*
 * Device type descriptor.
 *
 * This structure contains device-specific data needed to identify and address a
 * type of device to be administered via the Gasket generic driver.
 *
 * Device IDs are per-driver. In other words, two drivers using the Gasket
 * framework will each have a distinct device 0 (for example).
 */
struct gasket_driver_desc {
	/* The name of this device type. */
	const char *name;

/* The name of this specific device model. */
	const char *chip_model;

/* The version of the chip specified in chip_model. */
	const char *chip_version;

/* The version of this driver: "1.0.0", "2.1.3", etc. */
	const char *driver_version;

/*
	 * Non-zero if we should create "legacy" (device and device-class-
	 * specific) character devices and sysfs nodes.
	 */
	/* Unused until Accel is upstreamed. */
	int legacy_support;

/* Major and minor numbers identifying the device. */
	int major, minor;

/* Module structure for this driver. */
	struct module *module;

/* PCI ID table. */
	const struct pci_device_id *pci_id_table;

/* The number of page tables handled by this driver. */
	int num_page_tables;

/* The index of the bar containing the page tables. */
	int page_table_bar_index;

/* Registers used to control each page table. */
	const struct gasket_page_table_config *page_table_configs;

/* The bit index indicating whether a PT entry is extended. */
	int page_table_extended_bit;

/*
	 * Legacy mmap address adjusment for legacy devices only. Should be 0
	 * for any new device.
	 */
	ulong legacy_mmap_address_offset;

/* Set of 6 bar descriptions that describe all PCIe bars.
	 * Note that BUS/AXI devices (i.e. non PCI devices) use those.
	 */
	struct gasket_bar_desc bar_descriptions[GASKET_NUM_BARS];

/*
	 * Coherent buffer description.
	 */
	struct gasket_coherent_buffer_desc coherent_buffer_description;

/* Interrupt type. (One of gasket_interrupt_type). */
	int interrupt_type;

/* Index of the bar containing the interrupt registers to program. */
	int interrupt_bar_index;

/* Number of interrupts in the gasket_interrupt_desc array */
	int num_interrupts;

/* Description of the interrupts for this device. */
	const struct gasket_interrupt_desc *interrupts;

/*
	 * If this device packs multiple interrupt->MSI-X mappings into a
	 * single register (i.e., "uses packed interrupts"), only a single bit
	 * width is supported for each interrupt mapping (unpacked/"full-width"
	 * interrupts are always supported). This value specifies that width. If
	 * packed interrupts are not used, this value is ignored.
	 */
	int interrupt_pack_width;

/* Driver callback functions - all may be NULL */
	/*
	 * device_open_cb: Callback for when a device node is opened in write
	 * mode.
	 * @dev: The gasket_dev struct for this driver instance.
	 *
	 * This callback should perform device-specific setup that needs to
	 * occur only once when a device is first opened.
	 */
	int (*device_open_cb)(struct gasket_dev *dev);

/*
	 * device_release_cb: Callback when a device is closed.
	 * @gasket_dev: The gasket_dev struct for this driver instance.
	 *
	 * This callback is called whenever a device node fd is closed, as
	 * opposed to device_close_cb, which is called when the _last_
	 * descriptor for an open file is closed. This call is intended to
	 * handle any per-user or per-fd cleanup.
	 */
	int (*device_release_cb)(struct gasket_dev *gasket_dev,
				 struct file *file);

/*
	 * device_close_cb: Callback for when a device node is closed for the
	 * last time.
	 * @dev: The gasket_dev struct for this driver instance.
	 *
	 * This callback should perform device-specific cleanup that only
	 * needs to occur when the last reference to a device node is closed.
	 *
	 * This call is intended to handle and device-wide cleanup, as opposed
	 * to per-fd cleanup (which should be handled by device_release_cb).
	 */
	int (*device_close_cb)(struct gasket_dev *dev);

/*
	 * get_mappable_regions_cb: Get descriptors of mappable device memory.
	 * @gasket_dev: Pointer to the struct gasket_dev for this device.
	 * @bar_index: BAR for which to retrieve memory ranges.
	 * @mappable_regions: Out-pointer to the list of mappable regions on the
	 * device/BAR for this process.
	 * @num_mappable_regions: Out-pointer for the size of mappable_regions.
	 *
	 * Called when handling mmap(), this callback is used to determine which
	 * regions of device memory may be mapped by the current process. This
	 * information is then compared to mmap request to determine which
	 * regions to actually map.
	 */
	int (*get_mappable_regions_cb)(struct gasket_dev *gasket_dev,
				       int bar_index,
				       struct gasket_mappable_region **mappable_regions,
				       int *num_mappable_regions);

/*
	 * ioctl_permissions_cb: Check permissions for generic ioctls.
	 * @filp: File structure pointer describing this node usage session.
	 * @cmd: ioctl number to handle.
	 * @arg: ioctl-specific data pointer.
	 *
	 * Returns 1 if the ioctl may be executed, 0 otherwise. If this callback
	 * isn't specified a default routine will be used, that only allows the
	 * original device opener (i.e, the "owner") to execute state-affecting
	 * ioctls.
	 */
	gasket_ioctl_permissions_cb_t ioctl_permissions_cb;

/*
	 * ioctl_handler_cb: Callback to handle device-specific ioctls.
	 * @filp: File structure pointer describing this node usage session.
	 * @cmd: ioctl number to handle.
	 * @arg: ioctl-specific data pointer.
	 *
	 * Invoked whenever an ioctl is called that the generic Gasket
	 * framework doesn't support. If no cb is registered, unknown ioctls
	 * return -EINVAL. Should return an error status (either -EINVAL or
	 * the error result of the ioctl being handled).
	 */
	gasket_ioctl_handler_cb_t ioctl_handler_cb;

/*
	 * device_status_cb: Callback to determine device health.
	 * @dev: Pointer to the gasket_dev struct for this device.
	 *
	 * Called to determine if the device is healthy or not. Should return
	 * a member of the gasket_status_type enum.
	 *
	 */
	int (*device_status_cb)(struct gasket_dev *dev);

/*
	 * hardware_revision_cb: Get the device's hardware revision.
	 * @dev: Pointer to the gasket_dev struct for this device.
	 *
	 * Called to determine the reported rev of the physical hardware.
	 * Revision should be >0. A negative return value is an error.
	 */
	int (*hardware_revision_cb)(struct gasket_dev *dev);

/*
	 * device_reset_cb: Reset the hardware in question.
	 * @dev: Pointer to the gasket_dev structure for this device.
	 *
	 * Called by reset ioctls. This function should not
	 * lock the gasket_dev mutex. It should return 0 on success
	 * and an error on failure.
	 */
	int (*device_reset_cb)(struct gasket_dev *dev);
};

/*
 * Register the specified device type with the framework.
 * @desc: Populated/initialized device type descriptor.
 *
 * This function does _not_ take ownership of desc; the underlying struct must
 * exist until the matching call to gasket_unregister_device.
 * This function should be called from your driver's module_init function.
 */
int gasket_register_device(const struct gasket_driver_desc *desc);

/*
 * Remove the specified device type from the framework.
 * @desc: Descriptor for the device type to unregister; it should have been
 *        passed to gasket_register_device in a previous call.
 *
 * This function should be called from your driver's module_exit function.
 */
void gasket_unregister_device(const struct gasket_driver_desc *desc);

/* Add a PCI gasket device. */
int gasket_pci_add_device(struct pci_dev *pci_dev,
			  struct gasket_dev **gasket_devp);
/* Remove a PCI gasket device. */
void gasket_pci_remove_device(struct pci_dev *pci_dev);

/* Add a platform gasket device. */
int gasket_platform_add_device(struct platform_device *pdev,
			       struct gasket_dev **gasket_devp);

/* Remove a platform gasket device. */
void gasket_platform_remove_device(struct platform_device *pdev);

/* Set DMA device to use (if different from PCI/platform device) */
void gasket_set_dma_device(struct gasket_dev *gasket_dev,
			   struct device *dma_dev);

/* Enable a Gasket device. */
int gasket_enable_device(struct gasket_dev *gasket_dev);

/* Disable a Gasket device. */
void gasket_disable_device(struct gasket_dev *gasket_dev);

/*
 * Reset the Gasket device.
 * @gasket_dev: Gasket device struct.
 *
 * Calls device_reset_cb. Returns 0 on success and an error code othewrise.
 * gasket_reset_nolock will not lock the mutex, gasket_reset will.
 *
 */
int gasket_reset(struct gasket_dev *gasket_dev);
int gasket_reset_nolock(struct gasket_dev *gasket_dev);

/*
 * Memory management functions. These will likely be spun off into their own
 * file in the future.
 */

/* Unmaps the specified mappable region from a VMA. */
int gasket_mm_unmap_region(const struct gasket_dev *gasket_dev,
			   struct vm_area_struct *vma,
			   const struct gasket_mappable_region *map_region);

/*
 * Get the ioctl permissions callback.
 * @gasket_dev: Gasket device structure.
 */
gasket_ioctl_permissions_cb_t
gasket_get_ioctl_permissions_cb(struct gasket_dev *gasket_dev);

/**
 * Lookup a name by number in a num_name table.
 * @num: Number to lookup.
 * @table: Array of num_name structures, the table for the lookup.
 *
 */
const char *gasket_num_name_lookup(uint num,
				   const struct gasket_num_name *table);

/* Handy inlines */
static inline u64 gasket_dev_read_64(struct gasket_dev *gasket_dev, int bar,
				       ulong location)
{
	return readq_relaxed(&gasket_dev->bar_data[bar].virt_base[location]);
}

static inline void gasket_dev_write_64(struct gasket_dev *dev, u64 value,
				       int bar, ulong location)
{
	writeq_relaxed(value, &dev->bar_data[bar].virt_base[location]);
}

static inline void gasket_dev_write_32(struct gasket_dev *dev, u32 value,
				       int bar, ulong location)
{
	writel_relaxed(value, &dev->bar_data[bar].virt_base[location]);
}

static inline u32 gasket_dev_read_32(struct gasket_dev *dev, int bar,
				     ulong location)
{
	return readl_relaxed(&dev->bar_data[bar].virt_base[location]);
}

static inline void gasket_read_modify_write_64(struct gasket_dev *dev, int bar,
					       ulong location, u64 value,
					       u64 mask_width, u64 mask_shift)
{
	u64 mask, tmp;

tmp = gasket_dev_read_64(dev, bar, location);
	mask = ((1ULL << mask_width) - 1) << mask_shift;
	tmp = (tmp & ~mask) | (value << mask_shift);
	gasket_dev_write_64(dev, tmp, bar, location);
}

static inline void gasket_read_modify_write_32(struct gasket_dev *dev, int bar,
					       ulong location, u32 value,
					       u32 mask_width, u32 mask_shift)
{
	u32 mask, tmp;

tmp = gasket_dev_read_32(dev, bar, location);
	mask = ((1 << mask_width) - 1) << mask_shift;
	tmp = (tmp & ~mask) | (value << mask_shift);
	gasket_dev_write_32(dev, tmp, bar, location);
}

/* Get the Gasket driver structure for a given device. */
const struct gasket_driver_desc *gasket_get_driver_desc(struct gasket_dev *dev);

/* Get the device structure for a given device. */
struct device *gasket_get_device(struct gasket_dev *dev);

/* Helper function, Asynchronous waits on a given set of bits. */
int gasket_wait_with_reschedule(struct gasket_dev *gasket_dev, int bar,
				u64 offset, u64 mask, u64 val,
				uint max_retries, u64 delay_ms);

#endif /* __GASKET_CORE_H__ */
07070100000016000081A40000000000000000000000016217DF4F00003CB2000000000000000000000000000000000000002C00000000gasket-driver-1.0.18/src/gasket_interrupt.c// SPDX-License-Identifier: GPL-2.0
/* Copyright (C) 2018 Google, Inc. */

#include "gasket_interrupt.h"

#include "gasket_constants.h"
#include "gasket_core.h"
#include "gasket_sysfs.h"
#include <linux/device.h>
#include <linux/interrupt.h>
#include <linux/printk.h>
#include <linux/spinlock.h>
#include <linux/version.h>
#ifdef GASKET_KERNEL_TRACE_SUPPORT
#define CREATE_TRACE_POINTS
#include <trace/events/gasket_interrupt.h>
#else
#define trace_gasket_interrupt_event(x, ...)
#endif
/* Retry attempts if the requested number of interrupts aren't available. */
#define MSIX_RETRY_COUNT 3

/* Instance interrupt management data. */
struct gasket_interrupt_data {
	/* The name associated with this interrupt data. */
	const char *name;

/* Interrupt type. See gasket_interrupt_type in gasket_core.h */
	int type;

/* The PCI device [if any] associated with the owning device. */
	struct pci_dev *pci_dev;

/* Set to 1 if MSI-X has successfully been configred, 0 otherwise. */
	int msix_configured;

/* The number of interrupts requested by the owning device. */
	int num_interrupts;

/* A pointer to the interrupt descriptor struct for this device. */
	const struct gasket_interrupt_desc *interrupts;

/* The index of the bar into which interrupts should be mapped. */
	int interrupt_bar_index;

/* The width of a single interrupt in a packed interrupt register. */
	int pack_width;

/*
	 * Design-wise, these elements should be bundled together, but
	 * pci_enable_msix's interface requires that they be managed
	 * individually (requires array of struct msix_entry).
	 */

/* The number of successfully configured interrupts. */
	int num_configured;

/* The MSI-X data for each requested/configured interrupt. */
	struct msix_entry *msix_entries;

/* The eventfd "callback" data for each interrupt. */
	struct eventfd_ctx **eventfd_ctxs;

/* Spinlock to protect read/write races to eventfd_ctxs. */
	rwlock_t eventfd_ctx_lock;

/* The number of times each interrupt has been called. */
	ulong *interrupt_counts;

/* Linux IRQ number. */
	int irq;
};

/* Structures to display interrupt counts in sysfs. */
enum interrupt_sysfs_attribute_type {
	ATTR_INTERRUPT_COUNTS,
};

/* Set up device registers for interrupt handling. */
static void gasket_interrupt_setup(struct gasket_dev *gasket_dev)
{
	int i;
	int pack_shift;
	u64 mask;
	u64 value;
	struct gasket_interrupt_data *interrupt_data =
		gasket_dev->interrupt_data;

if (!interrupt_data) {
		dev_dbg(gasket_dev->dev, "Interrupt data is not initialized\n");
		return;
	}

dev_dbg(gasket_dev->dev, "Running interrupt setup\n");

if (interrupt_data->type == DEVICE_MANAGED)
		return; /* device driver handles setup */

/* Setup the MSIX table. */

for (i = 0; i < interrupt_data->num_interrupts; i++) {
		/*
		 * If the interrupt is not packed, we can write the index into
		 * the register directly. If not, we need to deal with a read-
		 * modify-write and shift based on the packing index.
		 */
		dev_dbg(gasket_dev->dev,
			"Setting up interrupt index %d with index 0x%llx and "
			"packing %d\n",
			interrupt_data->interrupts[i].index,
			interrupt_data->interrupts[i].reg,
			interrupt_data->interrupts[i].packing);
		if (interrupt_data->interrupts[i].packing == UNPACKED) {
			value = interrupt_data->interrupts[i].index;
		} else {
			switch (interrupt_data->interrupts[i].packing) {
			case PACK_0:
				pack_shift = 0;
				break;
			case PACK_1:
				pack_shift = interrupt_data->pack_width;
				break;
			case PACK_2:
				pack_shift = 2 * interrupt_data->pack_width;
				break;
			case PACK_3:
				pack_shift = 3 * interrupt_data->pack_width;
				break;
			default:
				dev_dbg(gasket_dev->dev,
					"Found interrupt description with "
					"unknown enum %d\n",
					interrupt_data->interrupts[i].packing);
				return;
			}

mask = ~(0xFFFF << pack_shift);
			value = gasket_dev_read_64(gasket_dev,
						   interrupt_data->interrupt_bar_index,
						   interrupt_data->interrupts[i].reg);
			value &= mask;
			value |= interrupt_data->interrupts[i].index
				 << pack_shift;
		}
		gasket_dev_write_64(gasket_dev, value,
				    interrupt_data->interrupt_bar_index,
				    interrupt_data->interrupts[i].reg);
	}
}

void
gasket_handle_interrupt(struct gasket_interrupt_data *interrupt_data,
			int interrupt_index)
{
	struct eventfd_ctx *ctx;

trace_gasket_interrupt_event(interrupt_data->name, interrupt_index);
	read_lock(&interrupt_data->eventfd_ctx_lock);
	ctx = interrupt_data->eventfd_ctxs[interrupt_index];
	if (ctx)
		eventfd_signal(ctx, 1);
	read_unlock(&interrupt_data->eventfd_ctx_lock);

++(interrupt_data->interrupt_counts[interrupt_index]);
}

static irqreturn_t gasket_msix_interrupt_handler(int irq, void *dev_id)
{
	struct gasket_interrupt_data *interrupt_data = dev_id;
	int interrupt = -1;
	int i;

/* If this linear lookup is a problem, we can maintain a map/hash. */
	for (i = 0; i < interrupt_data->num_interrupts; i++) {
		if (interrupt_data->msix_entries[i].vector == irq) {
			interrupt = interrupt_data->msix_entries[i].entry;
			break;
		}
	}
	if (interrupt == -1) {
		pr_err("Received unknown irq %d\n", irq);
		return IRQ_HANDLED;
	}
	gasket_handle_interrupt(interrupt_data, interrupt);
	return IRQ_HANDLED;
}

static int
gasket_interrupt_msix_init(struct gasket_interrupt_data *interrupt_data)
{
	int ret = 1;
	int i;

interrupt_data->msix_entries =
		kcalloc(interrupt_data->num_interrupts,
			sizeof(struct msix_entry), GFP_KERNEL);
	if (!interrupt_data->msix_entries)
		return -ENOMEM;

for (i = 0; i < interrupt_data->num_interrupts; i++) {
		interrupt_data->msix_entries[i].entry = i;
		interrupt_data->msix_entries[i].vector = 0;
		interrupt_data->eventfd_ctxs[i] = NULL;
	}

/* Retry MSIX_RETRY_COUNT times if not enough IRQs are available. */
	for (i = 0; i < MSIX_RETRY_COUNT && ret > 0; i++)
		ret = pci_enable_msix_exact(interrupt_data->pci_dev,
					    interrupt_data->msix_entries,
					    interrupt_data->num_interrupts);

if (ret)
		return ret > 0 ? -EBUSY : ret;
	interrupt_data->msix_configured = 1;

for (i = 0; i < interrupt_data->num_interrupts; i++) {
		ret = request_irq(interrupt_data->msix_entries[i].vector,
				  gasket_msix_interrupt_handler, 0,
				  interrupt_data->name, interrupt_data);

if (ret) {
			dev_err(&interrupt_data->pci_dev->dev,
				"Cannot get IRQ for interrupt %d, vector %d; "
				"%d\n",
				i, interrupt_data->msix_entries[i].vector, ret);
			return ret;
		}

interrupt_data->num_configured++;
	}

return 0;
}

/*
 * On QCM DragonBoard, we exit gasket_interrupt_msix_init() and kernel interrupt
 * setup code with MSIX vectors masked. This is wrong because nothing else in
 * the driver will normally touch the MSIX vectors.
 *
 * As a temporary hack, force unmasking there.
 *
 * TODO: Figure out why QCM kernel doesn't unmask the MSIX vectors, after
 * gasket_interrupt_msix_init(), and remove this code.
 */
static void force_msix_interrupt_unmasking(struct gasket_dev *gasket_dev)
{
	int i;
#define MSIX_VECTOR_SIZE 16
#define MSIX_MASK_BIT_OFFSET 12
#define APEX_BAR2_REG_KERNEL_HIB_MSIX_TABLE 0x46800
	for (i = 0; i < gasket_dev->interrupt_data->num_configured; i++) {
		/* Check if the MSIX vector is unmasked */
		ulong location = APEX_BAR2_REG_KERNEL_HIB_MSIX_TABLE +
				 MSIX_MASK_BIT_OFFSET + i * MSIX_VECTOR_SIZE;
		u32 mask =
			gasket_dev_read_32(gasket_dev,
					   gasket_dev->interrupt_data->interrupt_bar_index,
					   location);
		if (!(mask & 1))
			continue;
		/* Unmask the msix vector (clear 32 bits) */
		gasket_dev_write_32(gasket_dev, 0,
				    gasket_dev->interrupt_data->interrupt_bar_index,
				    location);
	}
#undef MSIX_VECTOR_SIZE
#undef MSIX_MASK_BIT_OFFSET
#undef APEX_BAR2_REG_KERNEL_HIB_MSIX_TABLE
}

static ssize_t interrupt_sysfs_show(struct device *device,
				    struct device_attribute *attr, char *buf)
{
	int i, ret;
	ssize_t written = 0, total_written = 0;
	struct gasket_interrupt_data *interrupt_data;
	struct gasket_dev *gasket_dev;
	struct gasket_sysfs_attribute *gasket_attr;
	enum interrupt_sysfs_attribute_type sysfs_type;

gasket_dev = gasket_sysfs_get_device_data(device);
	if (!gasket_dev) {
		dev_dbg(device, "No sysfs mapping found for device\n");
		return 0;
	}

gasket_attr = gasket_sysfs_get_attr(device, attr);
	if (!gasket_attr) {
		dev_dbg(device, "No sysfs attr data found for device\n");
		gasket_sysfs_put_device_data(device, gasket_dev);
		return 0;
	}

sysfs_type = (enum interrupt_sysfs_attribute_type)
		gasket_attr->data.attr_type;
	interrupt_data = gasket_dev->interrupt_data;
	switch (sysfs_type) {
	case ATTR_INTERRUPT_COUNTS:
		for (i = 0; i < interrupt_data->num_interrupts; ++i) {
			written =
				scnprintf(buf, PAGE_SIZE - total_written,
					  "0x%02x: %ld\n", i,
					  interrupt_data->interrupt_counts[i]);
			total_written += written;
			buf += written;
		}
		ret = total_written;
		break;
	default:
		dev_dbg(gasket_dev->dev, "Unknown attribute: %s\n",
			attr->attr.name);
		ret = 0;
		break;
	}

gasket_sysfs_put_attr(device, gasket_attr);
	gasket_sysfs_put_device_data(device, gasket_dev);
	return ret;
}

static struct gasket_sysfs_attribute interrupt_sysfs_attrs[] = {
	GASKET_SYSFS_RO(interrupt_counts, interrupt_sysfs_show,
			ATTR_INTERRUPT_COUNTS),
	GASKET_END_OF_ATTR_ARRAY,
};

int gasket_interrupt_init(struct gasket_dev *gasket_dev)
{
	int ret;
	struct gasket_interrupt_data *interrupt_data;
	const struct gasket_driver_desc *driver_desc =
		gasket_get_driver_desc(gasket_dev);

interrupt_data = kzalloc(sizeof(struct gasket_interrupt_data),
				 GFP_KERNEL);
	if (!interrupt_data)
		return -ENOMEM;
	gasket_dev->interrupt_data = interrupt_data;
	interrupt_data->name = driver_desc->name;
	interrupt_data->type = driver_desc->interrupt_type;
	interrupt_data->pci_dev = gasket_dev->pci_dev;
	interrupt_data->num_interrupts = driver_desc->num_interrupts;
	interrupt_data->interrupts = driver_desc->interrupts;
	interrupt_data->interrupt_bar_index = driver_desc->interrupt_bar_index;
	interrupt_data->pack_width = driver_desc->interrupt_pack_width;

interrupt_data->eventfd_ctxs = kcalloc(driver_desc->num_interrupts,
					       sizeof(struct eventfd_ctx *),
					       GFP_KERNEL);
	if (!interrupt_data->eventfd_ctxs) {
		kfree(interrupt_data);
		return -ENOMEM;
	}

interrupt_data->interrupt_counts = kcalloc(driver_desc->num_interrupts,
						   sizeof(ulong),
						   GFP_KERNEL);
	if (!interrupt_data->interrupt_counts) {
		kfree(interrupt_data->eventfd_ctxs);
		kfree(interrupt_data);
		return -ENOMEM;
	}

rwlock_init(&interrupt_data->eventfd_ctx_lock);

switch (interrupt_data->type) {
	case PCI_MSIX:
		ret = gasket_interrupt_msix_init(interrupt_data);
		if (ret)
			break;
		force_msix_interrupt_unmasking(gasket_dev);
		break;

case DEVICE_MANAGED:  /* Device driver manages IRQ init */
		interrupt_data->num_configured = interrupt_data->num_interrupts;
		ret = 0;
		break;

default:
		ret = -EINVAL;
	}

if (ret) {
		/* Failing to setup interrupts will cause the device to report
		 * GASKET_STATUS_LAMED. But it is not fatal.
		 */
		dev_warn(gasket_dev->dev,
			 "Couldn't initialize interrupts: %d\n", ret);
		return 0;
	}

gasket_interrupt_setup(gasket_dev);
	gasket_sysfs_create_entries(gasket_dev->dev_info.device,
				    interrupt_sysfs_attrs);

return 0;
}
EXPORT_SYMBOL(gasket_interrupt_init);

void gasket_interrupt_msix_cleanup(struct gasket_interrupt_data *interrupt_data)
{
	int i;

for (i = 0; i < interrupt_data->num_configured; i++) {
		gasket_interrupt_clear_eventfd(interrupt_data, i);
		free_irq(interrupt_data->msix_entries[i].vector,
			 interrupt_data);
	}
	interrupt_data->num_configured = 0;

if (interrupt_data->msix_configured)
		pci_disable_msix(interrupt_data->pci_dev);
	interrupt_data->msix_configured = 0;
	kfree(interrupt_data->msix_entries);
	interrupt_data->msix_entries = NULL;
}
EXPORT_SYMBOL(gasket_interrupt_msix_cleanup);

int gasket_interrupt_reinit(struct gasket_dev *gasket_dev)
{
	int ret;

if (!gasket_dev->interrupt_data) {
		dev_dbg(gasket_dev->dev,
			"Attempted to reinit uninitialized interrupt data\n");
		return -EINVAL;
	}

switch (gasket_dev->interrupt_data->type) {
	case PCI_MSIX:
		gasket_interrupt_msix_cleanup(gasket_dev->interrupt_data);
		ret = gasket_interrupt_msix_init(gasket_dev->interrupt_data);
		if (ret)
			break;
		force_msix_interrupt_unmasking(gasket_dev);
		break;

case DEVICE_MANAGED: /* Device driver manages IRQ reinit */
		ret = 0;
		break;

default:
		ret = -EINVAL;
	}

if (ret) {
		/* Failing to setup interrupts will cause the device
		 * to report GASKET_STATUS_LAMED, but is not fatal.
		 */
		dev_warn(gasket_dev->dev, "Couldn't reinit interrupts: %d\n",
			 ret);
		return 0;
	}

gasket_interrupt_setup(gasket_dev);

return 0;
}
EXPORT_SYMBOL(gasket_interrupt_reinit);

/* See gasket_interrupt.h for description. */
int gasket_interrupt_reset_counts(struct gasket_dev *gasket_dev)
{
	dev_dbg(gasket_dev->dev, "Clearing interrupt counts\n");
	memset(gasket_dev->interrupt_data->interrupt_counts, 0,
	       gasket_dev->interrupt_data->num_interrupts *
			sizeof(*gasket_dev->interrupt_data->interrupt_counts));
	return 0;
}

/* See gasket_interrupt.h for description. */
void gasket_interrupt_cleanup(struct gasket_dev *gasket_dev)
{
	struct gasket_interrupt_data *interrupt_data =
		gasket_dev->interrupt_data;
	/*
	 * It is possible to get an error code from gasket_interrupt_init
	 * before interrupt_data has been allocated, so check it.
	 */
	if (!interrupt_data)
		return;

switch (interrupt_data->type) {
	case PCI_MSIX:
		gasket_interrupt_msix_cleanup(interrupt_data);
		break;

case DEVICE_MANAGED: /* Device driver manages IRQ cleanup */
		break;

default:
		break;
	}

kfree(interrupt_data->interrupt_counts);
	kfree(interrupt_data->eventfd_ctxs);
	kfree(interrupt_data);
	gasket_dev->interrupt_data = NULL;
}

int gasket_interrupt_system_status(struct gasket_dev *gasket_dev)
{
	if (!gasket_dev->interrupt_data) {
		dev_dbg(gasket_dev->dev, "Interrupt data is null\n");
		return GASKET_STATUS_DEAD;
	}

if (gasket_dev->interrupt_data->num_configured !=
		gasket_dev->interrupt_data->num_interrupts) {
		dev_dbg(gasket_dev->dev,
			"Not all interrupts were configured\n");
		return GASKET_STATUS_LAMED;
	}

return GASKET_STATUS_ALIVE;
}

int gasket_interrupt_set_eventfd(struct gasket_interrupt_data *interrupt_data,
				 int interrupt, int event_fd)
{
	struct eventfd_ctx *ctx;
	ulong flags;

if (interrupt < 0 || interrupt >= interrupt_data->num_interrupts)
		return -EINVAL;

ctx = eventfd_ctx_fdget(event_fd);
	if (IS_ERR(ctx))
		return PTR_ERR(ctx);

/* Put the old eventfd ctx before setting, else we leak the ref. */
	write_lock_irqsave(&interrupt_data->eventfd_ctx_lock, flags);
	if (interrupt_data->eventfd_ctxs[interrupt] != NULL)
		eventfd_ctx_put(interrupt_data->eventfd_ctxs[interrupt]);
	interrupt_data->eventfd_ctxs[interrupt] = ctx;
	write_unlock_irqrestore(&interrupt_data->eventfd_ctx_lock, flags);
	return 0;
}

int gasket_interrupt_clear_eventfd(struct gasket_interrupt_data *interrupt_data,
				   int interrupt)
{
	ulong flags;

if (interrupt < 0 || interrupt >= interrupt_data->num_interrupts)
		return -EINVAL;

/* Put the old eventfd ctx before clearing, else we leak the ref. */
	write_lock_irqsave(&interrupt_data->eventfd_ctx_lock, flags);
	if (interrupt_data->eventfd_ctxs[interrupt] != NULL)
		eventfd_ctx_put(interrupt_data->eventfd_ctxs[interrupt]);
	interrupt_data->eventfd_ctxs[interrupt] = NULL;
	write_unlock_irqrestore(&interrupt_data->eventfd_ctx_lock, flags);
	return 0;
}
07070100000017000081A40000000000000000000000016217DF4F00000D61000000000000000000000000000000000000002C00000000gasket-driver-1.0.18/src/gasket_interrupt.h/* SPDX-License-Identifier: GPL-2.0 */
/*
 * Gasket common interrupt module. Defines functions for enabling
 * eventfd-triggered interrupts between a Gasket device and a host process.
 *
 * Copyright (C) 2018 Google, Inc.
 */
#ifndef __GASKET_INTERRUPT_H__
#define __GASKET_INTERRUPT_H__

#include <linux/eventfd.h>
#include <linux/pci.h>

#include "gasket_core.h"

/* Note that this currently assumes that device interrupts are a dense set,
 * numbered from 0 - (num_interrupts - 1). Should this have to change, these
 * APIs will have to be updated.
 */

/* Opaque type used to hold interrupt subsystem data. */
struct gasket_interrupt_data;

/*
 * Initialize the interrupt module.
 * @gasket_dev: The Gasket device structure for the device to be initted.
 */
int gasket_interrupt_init(struct gasket_dev *gasket_dev);

/*
 * Clean up a device's interrupt structure.
 * @gasket_dev: The Gasket information structure for this device.
 *
 * Cleans up the device's interrupts and deallocates data.
 */
void gasket_interrupt_cleanup(struct gasket_dev *gasket_dev);

/*
 * Clean up and re-initialize the MSI-x subsystem.
 * @gasket_dev: The Gasket information structure for this device.
 *
 * Performs a teardown of the MSI-x subsystem and re-initializes it. Does not
 * free the underlying data structures. Returns 0 on success and an error code
 * on error.
 */
int gasket_interrupt_reinit(struct gasket_dev *gasket_dev);

/*
 * Clean up the MSI-x subsystem.
 * @interrupt_data: The interrupt data structure for this device.
 *
 * Performs a teardown of the MSI-x subsystem. Does not free the underlying data structures.
 */
void gasket_interrupt_msix_cleanup(struct gasket_interrupt_data *interrupt_data);

/* Handle gasket interrupt processing, called from an external handler. */
void
gasket_handle_interrupt(struct gasket_interrupt_data *interrupt_data,
			int interrupt_index);

/*
 * Reset the counts stored in the interrupt subsystem.
 * @gasket_dev: The Gasket information structure for this device.
 *
 * Sets the counts of all interrupts in the subsystem to 0.
 */
int gasket_interrupt_reset_counts(struct gasket_dev *gasket_dev);

/*
 * Associates an eventfd with a device interrupt.
 * @data: Pointer to device interrupt data.
 * @interrupt: The device interrupt to configure.
 * @event_fd: The eventfd to associate with the interrupt.
 *
 * Prepares the host to receive notification of device interrupts by associating
 * event_fd with interrupt. Upon receipt of a device interrupt, event_fd will be
 * signaled, after successful configuration.
 *
 * Returns 0 on success, a negative error code otherwise.
 */
int gasket_interrupt_set_eventfd(struct gasket_interrupt_data *interrupt_data,
				 int interrupt, int event_fd);

/*
 * Removes an interrupt-eventfd association.
 * @data: Pointer to device interrupt data.
 * @interrupt: The device interrupt to de-associate.
 *
 * Removes any eventfd associated with the specified interrupt, if any.
 */
int gasket_interrupt_clear_eventfd(struct gasket_interrupt_data *interrupt_data,
				   int interrupt);

/*
 * The below functions exist for backwards compatibility.
 * No new uses should be written.
 */
/*
 * Get the health of the interrupt subsystem.
 * @gasket_dev: The Gasket device struct.
 *
 * Returns DEAD if not set up, LAMED if initialization failed, and ALIVE
 * otherwise.
 */

int gasket_interrupt_system_status(struct gasket_dev *gasket_dev);

#endif
07070100000018000081A40000000000000000000000016217DF4F00003437000000000000000000000000000000000000002800000000gasket-driver-1.0.18/src/gasket_ioctl.c// SPDX-License-Identifier: GPL-2.0
/* Copyright (C) 2018 Google, Inc. */
#include "gasket.h"
#include "gasket_ioctl.h"
#include "gasket_constants.h"
#include "gasket_core.h"
#include "gasket_interrupt.h"
#include "gasket_page_table.h"
#include <linux/compiler.h>
#include <linux/device.h>
#include <linux/fs.h>
#include <linux/uaccess.h>

#ifdef GASKET_KERNEL_TRACE_SUPPORT
#define CREATE_TRACE_POINTS
#include <trace/events/gasket_ioctl.h>
#else
#define trace_gasket_ioctl_entry(x, ...)
#define trace_gasket_ioctl_exit(x)
#define trace_gasket_ioctl_integer_data(x)
#define trace_gasket_ioctl_eventfd_data(x, ...)
#define trace_gasket_ioctl_page_table_data(x, ...)
#define trace_gasket_ioctl_page_table_flags_data(x, ...)
#define trace_gasket_ioctl_config_coherent_allocator(x, ...)
#endif

/* Associate an eventfd with an interrupt. */
static int gasket_set_event_fd(struct gasket_dev *gasket_dev,
			       struct gasket_interrupt_eventfd __user *argp)
{
	struct gasket_interrupt_eventfd die;

if (copy_from_user(&die, argp, sizeof(struct gasket_interrupt_eventfd)))
		return -EFAULT;

trace_gasket_ioctl_eventfd_data(die.interrupt, die.event_fd);

return gasket_interrupt_set_eventfd(
		gasket_dev->interrupt_data, die.interrupt, die.event_fd);
}

/* Read the size of the page table. */
static int gasket_read_page_table_size(
	struct gasket_dev *gasket_dev,
	struct gasket_page_table_ioctl __user *argp)
{
	int ret = 0;
	struct gasket_page_table_ioctl ibuf;

if (copy_from_user(&ibuf, argp, sizeof(struct gasket_page_table_ioctl)))
		return -EFAULT;

if (ibuf.page_table_index >= gasket_dev->num_page_tables)
		return -EFAULT;

ibuf.size = gasket_page_table_num_entries(
		gasket_dev->page_table[ibuf.page_table_index]);

trace_gasket_ioctl_page_table_data(
		ibuf.page_table_index, ibuf.size, ibuf.host_address,
		ibuf.device_address);

if (copy_to_user(argp, &ibuf, sizeof(ibuf)))
		return -EFAULT;

return ret;
}

/* Read the size of the simple page table. */
static int gasket_read_simple_page_table_size(
	struct gasket_dev *gasket_dev,
	struct gasket_page_table_ioctl __user *argp)
{
	int ret = 0;
	struct gasket_page_table_ioctl ibuf;

if (copy_from_user(&ibuf, argp, sizeof(struct gasket_page_table_ioctl)))
		return -EFAULT;

if (ibuf.page_table_index >= gasket_dev->num_page_tables)
		return -EFAULT;

ibuf.size =
		gasket_page_table_num_simple_entries(gasket_dev->page_table[ibuf.page_table_index]);

trace_gasket_ioctl_page_table_data(ibuf.page_table_index, ibuf.size,
					   ibuf.host_address,
					   ibuf.device_address);

if (copy_to_user(argp, &ibuf, sizeof(ibuf)))
		return -EFAULT;

return ret;
}

/* Set the boundary between the simple and extended page tables. */
static int gasket_partition_page_table(
	struct gasket_dev *gasket_dev,
	struct gasket_page_table_ioctl __user *argp)
{
	int ret;
	struct gasket_page_table_ioctl ibuf;
	uint max_page_table_size;

if (copy_from_user(&ibuf, argp, sizeof(struct gasket_page_table_ioctl)))
		return -EFAULT;

trace_gasket_ioctl_page_table_data(
		ibuf.page_table_index, ibuf.size, ibuf.host_address,
		ibuf.device_address);

if (ibuf.page_table_index >= gasket_dev->num_page_tables)
		return -EFAULT;
	max_page_table_size = gasket_page_table_max_size(
		gasket_dev->page_table[ibuf.page_table_index]);

if (ibuf.size > max_page_table_size) {
		dev_dbg(gasket_dev->dev,
			"Partition request 0x%llx too large, max is 0x%x\n",
			ibuf.size, max_page_table_size);
		return -EINVAL;
	}

mutex_lock(&gasket_dev->mutex);

ret = gasket_page_table_partition(
		gasket_dev->page_table[ibuf.page_table_index], ibuf.size);
	mutex_unlock(&gasket_dev->mutex);

return ret;
}

/* Map a userspace buffer to a device virtual address. */
static int gasket_map_buffers_common(struct gasket_dev *gasket_dev,
				     struct gasket_page_table_ioctl_flags
				     *pibuf)
{
	if (pibuf->base.page_table_index >= gasket_dev->num_page_tables)
		return -EFAULT;

if (gasket_page_table_are_addrs_bad(gasket_dev->page_table[pibuf->base.page_table_index],
					    pibuf->base.host_address,
					    pibuf->base.device_address,
					    pibuf->base.size))
		return -EINVAL;

return gasket_page_table_map(gasket_dev->page_table[pibuf->base.page_table_index],
				     pibuf->base.host_address,
				     pibuf->base.device_address,
				     pibuf->base.size / PAGE_SIZE,
				     pibuf->flags);
}

static int gasket_map_buffers(struct gasket_dev *gasket_dev,
			      struct gasket_page_table_ioctl __user *argp)
{
	struct gasket_page_table_ioctl_flags ibuf;
 
	if (copy_from_user(&ibuf.base, argp, sizeof(struct gasket_page_table_ioctl)))
 		return -EFAULT;
 
	ibuf.flags = 0;
 
	trace_gasket_ioctl_page_table_data(ibuf.base.page_table_index,
					   ibuf.base.size,
					   ibuf.base.host_address,
					   ibuf.base.device_address);

return gasket_map_buffers_common(gasket_dev, &ibuf);
}

static int gasket_map_buffers_flags(struct gasket_dev *gasket_dev,
				    struct gasket_page_table_ioctl_flags __user *argp)
{
	struct gasket_page_table_ioctl_flags ibuf;

if (copy_from_user(&ibuf, argp, sizeof(struct gasket_page_table_ioctl_flags)))
 		return -EFAULT;
 
	trace_gasket_ioctl_page_table_flags_data(ibuf.base.page_table_index,
						 ibuf.base.size,
						 ibuf.base.host_address,
						 ibuf.base.device_address,
						 ibuf.flags);
 
	return gasket_map_buffers_common(gasket_dev, &ibuf);
}

/* Unmap a userspace buffer from a device virtual address. */
static int gasket_unmap_buffers(struct gasket_dev *gasket_dev,
				struct gasket_page_table_ioctl __user *argp)
{
	struct gasket_page_table_ioctl ibuf;

if (copy_from_user(&ibuf, argp, sizeof(struct gasket_page_table_ioctl)))
		return -EFAULT;

trace_gasket_ioctl_page_table_data(ibuf.page_table_index, ibuf.size,
					   ibuf.host_address,
					   ibuf.device_address);

if (ibuf.page_table_index >= gasket_dev->num_page_tables)
		return -EFAULT;

if (gasket_page_table_is_dev_addr_bad(gasket_dev->page_table[ibuf.page_table_index],
					      ibuf.device_address, ibuf.size))
		return -EINVAL;

gasket_page_table_unmap(gasket_dev->page_table[ibuf.page_table_index],
				ibuf.device_address, ibuf.size / PAGE_SIZE);

return 0;
}

/* Map/unmap dma-buf to/from a device virtual address. */
static int gasket_map_dmabuf(struct gasket_dev *gasket_dev,
			     struct gasket_page_table_ioctl_dmabuf __user *argp)
{
	struct gasket_page_table_ioctl_dmabuf dbuf;
	struct gasket_page_table *pg_tbl;

if (copy_from_user(&dbuf, argp, sizeof(dbuf)))
		return -EFAULT;

if (dbuf.page_table_index >= gasket_dev->num_page_tables)
		return -EFAULT;

pg_tbl = gasket_dev->page_table[dbuf.page_table_index];
	if (gasket_page_table_is_dev_addr_bad(pg_tbl,
					      dbuf.device_address,
					      dbuf.num_pages * PAGE_SIZE))
		return -EINVAL;

if (dbuf.map)
		return gasket_page_table_map_dmabuf(pg_tbl,
						    dbuf.dmabuf_fd,
						    dbuf.device_address,
						    dbuf.num_pages,
						    dbuf.flags);
	else
		return gasket_page_table_unmap_dmabuf(pg_tbl,
						      dbuf.dmabuf_fd,
						      dbuf.device_address,
						      dbuf.num_pages);
}

/*
 * Reserve structures for coherent allocation, and allocate or free the
 * corresponding memory.
 */
static int gasket_config_coherent_allocator(
	struct gasket_dev *gasket_dev,
	struct gasket_coherent_alloc_config_ioctl __user *argp)
{
	int ret;
	struct gasket_coherent_alloc_config_ioctl ibuf;
	dma_addr_t dma_address;

if (copy_from_user(&ibuf, argp,
			   sizeof(struct gasket_coherent_alloc_config_ioctl)))
		return -EFAULT;

trace_gasket_ioctl_config_coherent_allocator(ibuf.enable, ibuf.size,
						     ibuf.dma_address);

if (ibuf.page_table_index >= gasket_dev->num_page_tables)
		return -EFAULT;

if (ibuf.size > PAGE_SIZE * MAX_NUM_COHERENT_PAGES)
		return -ENOMEM;

if (ibuf.enable == 0) {
		dma_address = ibuf.dma_address;
		ret = gasket_free_coherent_memory(gasket_dev, ibuf.size,
						  dma_address,
						  ibuf.page_table_index);
	} else {
		ret = gasket_alloc_coherent_memory(gasket_dev, ibuf.size,
						   &dma_address,
						   ibuf.page_table_index);
	}
	if (ret)
		return ret;

if (ibuf.enable != 0)
		ibuf.dma_address = dma_address;

if (copy_to_user(argp, &ibuf, sizeof(ibuf)))
		return -EFAULT;

return 0;
}

/* Check permissions for Gasket ioctls. */
static bool gasket_ioctl_check_permissions(struct file *filp, uint cmd)
{
	bool alive;
	bool read, write;
	struct gasket_dev *gasket_dev = (struct gasket_dev *)filp->private_data;

alive = (gasket_dev->status == GASKET_STATUS_ALIVE);
	if (!alive)
		dev_dbg(gasket_dev->dev, "%s alive %d status %d\n",
			__func__, alive, gasket_dev->status);

read = !!(filp->f_mode & FMODE_READ);
	write = !!(filp->f_mode & FMODE_WRITE);

switch (cmd) {
	case GASKET_IOCTL_RESET:
	case GASKET_IOCTL_CLEAR_INTERRUPT_COUNTS:
		return write;

case GASKET_IOCTL_PAGE_TABLE_SIZE:
	case GASKET_IOCTL_SIMPLE_PAGE_TABLE_SIZE:
	case GASKET_IOCTL_NUMBER_PAGE_TABLES:
		return read;

case GASKET_IOCTL_PARTITION_PAGE_TABLE:
	case GASKET_IOCTL_CONFIG_COHERENT_ALLOCATOR:
		return alive && write;

case GASKET_IOCTL_MAP_BUFFER:
	case GASKET_IOCTL_MAP_BUFFER_FLAGS:
	case GASKET_IOCTL_UNMAP_BUFFER:
	case GASKET_IOCTL_MAP_DMABUF:
		return alive && write;

case GASKET_IOCTL_CLEAR_EVENTFD:
	case GASKET_IOCTL_SET_EVENTFD:
		return alive && write;
	}

return false; /* unknown permissions */
}

/*
 * standard ioctl dispatch function.
 * @filp: File structure pointer describing this node usage session.
 * @cmd: ioctl number to handle.
 * @argp: ioctl-specific data pointer.
 *
 * Standard ioctl dispatcher; forwards operations to individual handlers.
 */
long gasket_handle_ioctl(struct file *filp, uint cmd, void __user *argp)
{
	struct gasket_dev *gasket_dev;
	unsigned long arg = (unsigned long)argp;
	gasket_ioctl_permissions_cb_t ioctl_permissions_cb;
	int retval;

gasket_dev = (struct gasket_dev *)filp->private_data;
	trace_gasket_ioctl_entry(gasket_dev->dev_info.name, cmd);

ioctl_permissions_cb = gasket_get_ioctl_permissions_cb(gasket_dev);
	if (ioctl_permissions_cb) {
		retval = ioctl_permissions_cb(filp, cmd, argp);
		if (retval < 0) {
			trace_gasket_ioctl_exit(retval);
			return retval;
		} else if (retval == 0) {
			trace_gasket_ioctl_exit(-EPERM);
			return -EPERM;
		}
	} else if (!gasket_ioctl_check_permissions(filp, cmd)) {
		trace_gasket_ioctl_exit(-EPERM);
		dev_dbg(gasket_dev->dev, "ioctl cmd=%x noperm\n", cmd);
		return -EPERM;
	}

/* Tracing happens in this switch statement for all ioctls with
	 * an integer argrument, but ioctls with a struct argument
	 * that needs copying and decoding, that tracing is done within
	 * the handler call.
	 */
	switch (cmd) {
	case GASKET_IOCTL_RESET:
		retval = gasket_reset(gasket_dev);
		break;
	case GASKET_IOCTL_SET_EVENTFD:
		retval = gasket_set_event_fd(gasket_dev, argp);
		break;
	case GASKET_IOCTL_CLEAR_EVENTFD:
		trace_gasket_ioctl_integer_data(arg);
		retval =
			gasket_interrupt_clear_eventfd(gasket_dev->interrupt_data,
						       (int)arg);
		break;
	case GASKET_IOCTL_PARTITION_PAGE_TABLE:
		trace_gasket_ioctl_integer_data(arg);
		retval = gasket_partition_page_table(gasket_dev, argp);
		break;
	case GASKET_IOCTL_NUMBER_PAGE_TABLES:
		trace_gasket_ioctl_integer_data(gasket_dev->num_page_tables);
		if (copy_to_user(argp, &gasket_dev->num_page_tables,
				 sizeof(uint64_t)))
			retval = -EFAULT;
		else
			retval = 0;
		break;
	case GASKET_IOCTL_PAGE_TABLE_SIZE:
		retval = gasket_read_page_table_size(gasket_dev, argp);
		break;
	case GASKET_IOCTL_SIMPLE_PAGE_TABLE_SIZE:
		retval = gasket_read_simple_page_table_size(gasket_dev, argp);
		break;
	case GASKET_IOCTL_MAP_BUFFER:
		retval = gasket_map_buffers(gasket_dev, argp);
		break;
	case GASKET_IOCTL_MAP_BUFFER_FLAGS:
		retval = gasket_map_buffers_flags(gasket_dev, argp);
		break;
	case GASKET_IOCTL_CONFIG_COHERENT_ALLOCATOR:
		retval = gasket_config_coherent_allocator(gasket_dev, argp);
		break;
	case GASKET_IOCTL_UNMAP_BUFFER:
		retval = gasket_unmap_buffers(gasket_dev, argp);
		break;
	case GASKET_IOCTL_CLEAR_INTERRUPT_COUNTS:
		/* Clear interrupt counts doesn't take an arg, so use 0. */
		trace_gasket_ioctl_integer_data(0);
		retval = gasket_interrupt_reset_counts(gasket_dev);
		break;
	case GASKET_IOCTL_MAP_DMABUF:
		retval = gasket_map_dmabuf(gasket_dev, argp);
		break;
	default:
		/* If we don't understand the ioctl, the best we can do is trace
		 * the arg.
		 */
		trace_gasket_ioctl_integer_data(arg);
		dev_dbg(gasket_dev->dev,
			"Unknown ioctl cmd=0x%x not caught by "
			"gasket_is_supported_ioctl\n",
			cmd);
		retval = -EINVAL;
		break;
	}

trace_gasket_ioctl_exit(retval);
	return retval;
}

/*
 * Determines if an ioctl is part of the standard Gasket framework.
 * @cmd: The ioctl number to handle.
 *
 * Returns 1 if the ioctl is supported and 0 otherwise.
 */
long gasket_is_supported_ioctl(uint cmd)
{
	switch (cmd) {
	case GASKET_IOCTL_RESET:
	case GASKET_IOCTL_SET_EVENTFD:
	case GASKET_IOCTL_CLEAR_EVENTFD:
	case GASKET_IOCTL_PARTITION_PAGE_TABLE:
	case GASKET_IOCTL_NUMBER_PAGE_TABLES:
	case GASKET_IOCTL_PAGE_TABLE_SIZE:
	case GASKET_IOCTL_SIMPLE_PAGE_TABLE_SIZE:
	case GASKET_IOCTL_MAP_BUFFER:
	case GASKET_IOCTL_MAP_BUFFER_FLAGS:
	case GASKET_IOCTL_UNMAP_BUFFER:
	case GASKET_IOCTL_MAP_DMABUF:
	case GASKET_IOCTL_CLEAR_INTERRUPT_COUNTS:
	case GASKET_IOCTL_CONFIG_COHERENT_ALLOCATOR:
		return 1;
	default:
		return 0;
	}
}
07070100000019000081A40000000000000000000000016217DF4F0000029D000000000000000000000000000000000000002800000000gasket-driver-1.0.18/src/gasket_ioctl.h/* SPDX-License-Identifier: GPL-2.0 */
/* Copyright (C) 2018 Google, Inc. */
#ifndef __GASKET_IOCTL_H__
#define __GASKET_IOCTL_H__

#include "gasket_core.h"

#include <linux/compiler.h>

/*
 * Handle Gasket common ioctls.
 * @filp: Pointer to the ioctl's file.
 * @cmd: Ioctl command.
 * @arg: Ioctl argument pointer.
 *
 * Returns 0 on success and nonzero on failure.
 */
long gasket_handle_ioctl(struct file *filp, uint cmd, void __user *argp);

#endif
0707010000001A000081A40000000000000000000000016217DF4F0000B387000000000000000000000000000000000000002D00000000gasket-driver-1.0.18/src/gasket_page_table.c// SPDX-License-Identifier: GPL-2.0
/*
 * Implementation of Gasket page table support.
 *
 * Copyright (C) 2018 Google, Inc.
 */

/*
 * Implementation of Gasket page table support.
 *
 * This file assumes 4kB pages throughout; can be factored out when necessary.
 *
 * There is a configurable number of page table entries, as well as a
 * configurable bit index for the extended address flag. Both of these are
 * specified in gasket_page_table_init through the page_table_config parameter.
 *
 * The following example assumes:
 *   page_table_config->total_entries = 8192
 *   page_table_config->extended_bit = 63
 *
 * Address format:
 * Simple addresses - those whose containing pages are directly placed in the
 * device's address translation registers - are laid out as:
 * [ 63 - 25: 0 | 24 - 12: page index | 11 - 0: page offset ]
 * page index:  The index of the containing page in the device's address
 *              translation registers.
 * page offset: The index of the address into the containing page.
 *
 * Extended address - those whose containing pages are contained in a second-
 * level page table whose address is present in the device's address translation
 * registers - are laid out as:
 * [ 63: flag | 62 - 34: 0 | 33 - 21: dev/level 0 index |
 *   20 - 12: host/level 1 index | 11 - 0: page offset ]
 * flag:        Marker indicating that this is an extended address. Always 1.
 * dev index:   The index of the first-level page in the device's extended
 *              address translation registers.
 * host index:  The index of the containing page in the [host-resident] second-
 *              level page table.
 * page offset: The index of the address into the containing [second-level]
 *              page.
 */
#include "gasket_page_table.h"

#include <linux/device.h>
#include <linux/dma-buf.h>
#include <linux/file.h>
#include <linux/init.h>
#include <linux/kernel.h>
#include <linux/list.h>
#include <linux/module.h>
#include <linux/moduleparam.h>
#include <linux/pagemap.h>
#include <linux/version.h>
#include <linux/vmalloc.h>

#if LINUX_VERSION_CODE >= KERNEL_VERSION(5,16,0)
MODULE_IMPORT_NS(DMA_BUF);
#endif

#include "gasket_constants.h"
#include "gasket_core.h"

/* Constants & utility macros */
/* The number of pages that can be mapped into each second-level page table. */
#define GASKET_PAGES_PER_SUBTABLE 512

/* The starting position of the page index in a simple virtual address. */
#define GASKET_SIMPLE_PAGE_SHIFT 12

/* Flag indicating that a [device] slot is valid for use. */
#define GASKET_VALID_SLOT_FLAG 1

/*
 * The starting position of the level 0 page index (i.e., the entry in the
 * device's extended address registers) in an extended address.
 * Also can be thought of as (log2(PAGE_SIZE) + log2(PAGES_PER_SUBTABLE)),
 * or (12 + 9).
 */
#define GASKET_EXTENDED_LVL0_SHIFT 21

/*
 * Number of first level pages that Gasket chips support. Equivalent to
 * log2(NUM_LVL0_PAGE_TABLES)
 *
 * At a maximum, allowing for a 34 bits address space (or 16GB)
 *   = GASKET_EXTENDED_LVL0_WIDTH + (log2(PAGE_SIZE) + log2(PAGES_PER_SUBTABLE)
 * or, = 13 + 9 + 12
 */
#define GASKET_EXTENDED_LVL0_WIDTH 13

/*
 * The starting position of the level 1 page index (i.e., the entry in the
 * host second-level/sub- table) in an extended address.
 */
#define GASKET_EXTENDED_LVL1_SHIFT 12

/*
 * Utilities for accessing flags bitfields.
 */
#define MASK(field)            (((1u << field##_WIDTH) - 1) << field##_SHIFT)
#define GET(field, flags)      (((flags) & MASK(field)) >> field##_SHIFT)
#define SET(field, flags, val) (((flags) & ~MASK(field)) | ((val) << field##_SHIFT))

#define FLAGS_STATUS_SHIFT 0
#define FLAGS_STATUS_WIDTH 1

#define FLAGS_DMA_DIRECTION_SHIFT 1
#define FLAGS_DMA_DIRECTION_WIDTH 2

/* Type declarations */
/* Valid states for a struct gasket_page_table_entry. */
enum pte_status {
	PTE_FREE,
	PTE_INUSE,
};

/*
 * Mapping metadata for a single page.
 *
 * In this file, host-side page table entries are referred to as that (or PTEs).
 * Where device vs. host entries are differentiated, device-side or -visible
 * entries are called "slots". A slot may be either an entry in the device's
 * address translation table registers or an entry in a second-level page
 * table ("subtable").
 *
 * The full data in this structure is visible on the host [of course]. Only
 * the address contained in dma_addr is communicated to the device; that points
 * to the actual page mapped and described by this structure.
 */
struct gasket_page_table_entry {
	/*
	 * Internal structure matches gasket_page_table_ioctl_flags.flags.
	 * NOTE: All fields should have a default value of 0. This ensures that
	 * the kernel will be backwards compatible with old drivers.
	 */
	u32 flags;

/*
	 * Index for alignment into host vaddrs.
	 * When a user specifies a host address for a mapping, that address may
	 * not be page-aligned. Offset is the index into the containing page of
	 * the host address (i.e., host_vaddr & (PAGE_SIZE - 1)).
	 * This is necessary for translating between user-specified addresses
	 * and page-aligned addresses.
	 */
	int offset;

/* Address of the page in DMA space. */
	dma_addr_t dma_addr;

/* Linux page descriptor for the page described by this structure. */
	struct page *page;

/*
	 * If this is an extended and first-level entry, sublevel points
	 * to the second-level entries underneath this entry.
	 */
	struct gasket_page_table_entry *sublevel;
};

/*
 * Maintains virtual to physical address mapping for a coherent page that is
 * allocated by this module for a given device.
 * Note that coherent pages mappings virt mapping cannot be tracked by the
 * Linux kernel, and coherent pages don't have a struct page associated,
 * hence Linux kernel cannot perform a get_user_page_xx() on a phys address
 * that was allocated coherent.
 * This structure trivially implements this mechanism.
 */
struct gasket_coherent_page_entry {
	/* Phys address, dma'able by the owner device */
	dma_addr_t paddr;

/* Kernel virtual address */
	u64 user_virt;

/* User virtual address that was mapped by the mmap kernel subsystem */
	dma_addr_t kernel_virt;

/*
	 * Whether this page has been mapped into a user land process virtual
	 * space
	 */
	u32 in_use;
};

/* Storage for dmabuf mapping information. */
struct gasket_dmabuf_mapping {
	struct dma_buf *dmabuf;
	struct dma_buf_attachment *attachment;
	struct sg_table *sgt;
	enum dma_data_direction direction;
	struct list_head list;
};

/*
 * [Host-side] page table descriptor.
 *
 * This structure tracks the metadata necessary to manage both simple and
 * extended page tables.
 */
struct gasket_page_table {
	/* The config used to create this page table. */
	struct gasket_page_table_config config;

/* The number of simple (single-level) entries in the page table. */
	uint num_simple_entries;

/* The number of extended (two-level) entries in the page table. */
	uint num_extended_entries;

/* Array of [host-side] page table entries. */
	struct gasket_page_table_entry *entries;

/* Number of actively mapped kernel pages in this table. */
	uint num_active_pages;

/* Device register: base of/first slot in the page table. */
	u64 __iomem *base_slot;

/* Device register: holds the offset indicating the start of the
	 * extended address region of the device's address translation table.
	 */
	u64 __iomem *extended_offset_reg;

/* Device structure for the underlying device. Only used for logging. */
	struct device *device;

/* PCI system descriptor for the underlying device. */
	struct pci_dev *pci_dev;

/* Location of the extended address bit for this Gasket device. */
	u64 extended_flag;

/* Mutex to protect page table internals. */
	struct mutex mutex;

/* Number of coherent pages accessible thru by this page table */
	int num_coherent_pages;

/*
	 * List of coherent memory (physical) allocated for a device.
	 *
	 * This structure also remembers the user virtual mapping, this is
	 * hacky, but we need to do this because the kernel doesn't keep track
	 * of the user coherent pages (pfn pages), and virt to coherent page
	 * mapping.
	 * TODO: use find_vma() APIs to convert host address to vm_area, to
	 * dma_addr_t instead of storing user virtu address in
	 * gasket_coherent_page_entry
	 *
	 * Note that the user virtual mapping is created by the driver, in
	 * gasket_mmap function, so user_virt belongs in the driver anyhow.
	 */
	struct gasket_coherent_page_entry *coherent_pages;

/* List of dmabufs currently attached and mapped. */
	struct list_head dmabufs;
};

/* See gasket_page_table.h for description. */
int gasket_page_table_init(struct gasket_page_table **ppg_tbl,
			   const struct gasket_bar_data *bar_data,
			   const struct gasket_page_table_config *page_table_config,
			   struct device *device, struct pci_dev *pci_dev)
{
	ulong bytes;
	struct gasket_page_table *pg_tbl;
	ulong total_entries = page_table_config->total_entries;

/*
	 * TODO: Verify config->total_entries against value read from the
	 * hardware register that contains the page table size.
	 */
	if (total_entries == ULONG_MAX) {
		dev_dbg(device, "Error reading page table size. "
			"Initializing page table with size 0\n");
		total_entries = 0;
	}

dev_dbg(device,
		"Attempting to initialize page table of size 0x%lx\n",
		total_entries);

dev_dbg(device,
		"Table has base reg 0x%x, extended offset reg 0x%x\n",
		page_table_config->base_reg,
		page_table_config->extended_reg);

*ppg_tbl = kzalloc(sizeof(**ppg_tbl), GFP_KERNEL);
	if (!*ppg_tbl) {
		dev_dbg(device, "No memory for page table\n");
		return -ENOMEM;
	}

pg_tbl = *ppg_tbl;
	bytes = total_entries * sizeof(struct gasket_page_table_entry);
	if (bytes != 0) {
		pg_tbl->entries = vzalloc(bytes);
		if (!pg_tbl->entries) {
			dev_dbg(device,
				"No memory for address translation metadata\n");
			kfree(pg_tbl);
			*ppg_tbl = NULL;
			return -ENOMEM;
		}
	}

mutex_init(&pg_tbl->mutex);
	memcpy(&pg_tbl->config, page_table_config, sizeof(*page_table_config));
	if (pg_tbl->config.mode == GASKET_PAGE_TABLE_MODE_NORMAL ||
	    pg_tbl->config.mode == GASKET_PAGE_TABLE_MODE_SIMPLE) {
		pg_tbl->num_simple_entries = total_entries;
		pg_tbl->num_extended_entries = 0;
		pg_tbl->extended_flag = 1ull << page_table_config->extended_bit;
	} else {
		pg_tbl->num_simple_entries = 0;
		pg_tbl->num_extended_entries = total_entries;
		pg_tbl->extended_flag = 0;
	}
	pg_tbl->num_active_pages = 0;
	pg_tbl->base_slot =
		(u64 __iomem *)&bar_data->virt_base[page_table_config->base_reg];
	pg_tbl->extended_offset_reg =
		(u64 __iomem *)&bar_data->virt_base[page_table_config->extended_reg];
	pg_tbl->device = get_device(device);
	pg_tbl->pci_dev = pci_dev;
	INIT_LIST_HEAD(&pg_tbl->dmabufs);

dev_dbg(device, "Page table initialized successfully\n");

return 0;
}

/*
 * Check if a range of PTEs is free.
 * The page table mutex must be held by the caller.
 */
static bool gasket_is_pte_range_free(struct gasket_page_table_entry *ptes,
				     uint num_entries)
{
	int i;

for (i = 0; i < num_entries; i++) {
		if (GET(FLAGS_STATUS, ptes[i].flags) != PTE_FREE)
			return false;
	}

return true;
}

/*
 * Free a second level page [sub]table.
 * The page table mutex must be held before this call.
 */
static void gasket_free_extended_subtable(struct gasket_page_table *pg_tbl,
					  struct gasket_page_table_entry *pte,
					  u64 __iomem *slot)
{
	/* Release the page table from the driver */
	pte->flags = SET(FLAGS_STATUS, pte->flags, PTE_FREE);

/* Release the page table from the device */
	writeq(0, slot);

if (pte->dma_addr)
		dma_unmap_page(pg_tbl->device, pte->dma_addr, PAGE_SIZE,
			       DMA_TO_DEVICE);

vfree(pte->sublevel);

if (pte->page)
		free_page((ulong)page_address(pte->page));

memset(pte, 0, sizeof(struct gasket_page_table_entry));
}

/*
 * Actually perform collection.
 * The page table mutex must be held by the caller.
 */
static void
gasket_page_table_garbage_collect_nolock(struct gasket_page_table *pg_tbl)
{
	struct gasket_page_table_entry *pte;
	u64 __iomem *slot;

/* XXX FIX ME XXX -- more efficient to keep a usage count */
	/* rather than scanning the second level page tables */

for (pte = pg_tbl->entries + pg_tbl->num_simple_entries,
	     slot = pg_tbl->base_slot + pg_tbl->num_simple_entries;
	     pte < pg_tbl->entries + pg_tbl->config.total_entries;
	     pte++, slot++) {
		if (GET(FLAGS_STATUS, pte->flags) == PTE_INUSE) {
			if (gasket_is_pte_range_free(pte->sublevel,
						     GASKET_PAGES_PER_SUBTABLE))
				gasket_free_extended_subtable(pg_tbl, pte,
							      slot);
		}
	}
}

/* See gasket_page_table.h for description. */
void gasket_page_table_garbage_collect(struct gasket_page_table *pg_tbl)
{
	mutex_lock(&pg_tbl->mutex);
	gasket_page_table_garbage_collect_nolock(pg_tbl);
	mutex_unlock(&pg_tbl->mutex);
}

/* See gasket_page_table.h for description. */
void gasket_page_table_cleanup(struct gasket_page_table *pg_tbl)
{
	/* Deallocate free second-level tables. */
	gasket_page_table_garbage_collect(pg_tbl);

/* TODO: Check that all PTEs have been freed? */

vfree(pg_tbl->entries);
	pg_tbl->entries = NULL;

put_device(pg_tbl->device);
	kfree(pg_tbl);
}

/* See gasket_page_table.h for description. */
int gasket_page_table_partition(struct gasket_page_table *pg_tbl,
				uint num_simple_entries)
{
	int i, start;

mutex_lock(&pg_tbl->mutex);
	if (num_simple_entries > pg_tbl->config.total_entries) {
		mutex_unlock(&pg_tbl->mutex);
		return -EINVAL;
	}

gasket_page_table_garbage_collect_nolock(pg_tbl);

start = min(pg_tbl->num_simple_entries, num_simple_entries);

for (i = start; i < pg_tbl->config.total_entries; i++) {
		if (GET(FLAGS_STATUS, pg_tbl->entries[i].flags) != PTE_FREE) {
			dev_err(pg_tbl->device, "entry %d is not free\n", i);
			mutex_unlock(&pg_tbl->mutex);
			return -EBUSY;
		}
	}

pg_tbl->num_simple_entries = num_simple_entries;
	pg_tbl->num_extended_entries =
		pg_tbl->config.total_entries - num_simple_entries;
	writeq(num_simple_entries, pg_tbl->extended_offset_reg);

mutex_unlock(&pg_tbl->mutex);
	return 0;
}
EXPORT_SYMBOL(gasket_page_table_partition);

/*
 * Return whether a host buffer was mapped as coherent memory.
 *
 * A Gasket page_table currently support one contiguous dma range, mapped to one
 * contiguous virtual memory range. Check if the host_addr is within that range.
 */
static int is_coherent(struct gasket_page_table *pg_tbl, ulong host_addr)
{
	u64 min, max;

/* whether the host address is within user virt range */
	if (!pg_tbl->coherent_pages)
		return 0;

min = (u64)pg_tbl->coherent_pages[0].user_virt;
	max = min + PAGE_SIZE * pg_tbl->num_coherent_pages;

return min <= host_addr && host_addr < max;
}

/* Safely return a page to the OS. */
static bool gasket_release_page(struct page *page)
{
	if (!page)
		return false;

if (!PageReserved(page))
		SetPageDirty(page);
	put_page(page);

return true;
}

/*
 * Get and map last level page table buffers.
 *
 * slots is the location(s) to write device-mapped page address. If this is a
 * simple mapping, these will be address translation registers. If this is
 * an extended mapping, these will be within a second-level page table
 * allocated by the host and so must have their __iomem attribute casted away.
 */
static int gasket_perform_mapping(struct gasket_page_table *pg_tbl,
				  struct gasket_page_table_entry *ptes,
				  u64 __iomem *slots,
				  struct sg_page_iter *sg_iter,
				  ulong host_addr,
				  uint num_pages, u32 flags,
				  int is_simple_mapping)
{
	int ret;
	ulong offset;
	struct page *page;
	dma_addr_t dma_addr;
	ulong page_addr;
	int i;
	enum dma_data_direction direction;

/* Must have a virtual host address or a sg iterator, but not both. */
	if (!((uintptr_t)host_addr ^ (uintptr_t)sg_iter)) {
		dev_err(pg_tbl->device, "need sg_iter or host_addr\n");
		return -EINVAL;
	}

direction = GET(FLAGS_DMA_DIRECTION, flags);
	if (direction == DMA_NONE) {
		dev_err(pg_tbl->device, "invalid DMA direction flags=0x%lx\n",
			(unsigned long)flags);
		return -EINVAL;
	}

for (i = 0; i < num_pages; i++) {
		page_addr = host_addr + i * PAGE_SIZE;
		offset = page_addr & (PAGE_SIZE - 1);
		dev_dbg(pg_tbl->device, "%s i %d\n", __func__, i);
		if (sg_iter) {
			if (!__sg_page_iter_next(sg_iter))
				return -EINVAL;

/* Page already mapped for DMA. */
#if LINUX_VERSION_CODE < KERNEL_VERSION(5, 1, 0)
			ptes[i].dma_addr = sg_page_iter_dma_address(sg_iter);
#else
			ptes[i].dma_addr = sg_page_iter_dma_address(
				container_of(sg_iter, struct sg_dma_page_iter, base));
#endif
			ptes[i].page = NULL;
			offset = 0;
		} else if (is_coherent(pg_tbl, host_addr)) {
			u64 off =
				(u64)host_addr -
				(u64)pg_tbl->coherent_pages[0].user_virt;
			ptes[i].page = NULL;
			ptes[i].offset = offset;
			ptes[i].dma_addr = pg_tbl->coherent_pages[0].paddr +
					   off + i * PAGE_SIZE;
		} else {
			ret = get_user_pages_fast(page_addr - offset, 1,
						  direction != DMA_TO_DEVICE,
						  &page);

if (ret <= 0) {
				dev_err(pg_tbl->device,
					"get user pages failed for addr=0x%lx, "
					"offset=0x%lx [ret=%d]\n",
					page_addr, offset, ret);
				return ret ? ret : -ENOMEM;
			}
			++pg_tbl->num_active_pages;

ptes[i].page = page;
			ptes[i].offset = offset;

/* Map the page into DMA space. */
			ptes[i].dma_addr = dma_map_page(pg_tbl->device, page, 0, PAGE_SIZE,
							GET(FLAGS_DMA_DIRECTION, flags));
			dev_dbg(pg_tbl->device,
				"%s i %d pte %p pfn %p -> mapped %llx\n",
				__func__, i, &ptes[i],
				(void *)page_to_pfn(page),
				(unsigned long long)ptes[i].dma_addr);

if (dma_mapping_error(pg_tbl->device,
					      ptes[i].dma_addr)) {
				dev_dbg(pg_tbl->device,
					"%s i %d -> fail to map page %llx "
					"[pfn %p phys %p]\n",
					__func__, i,
					(unsigned long long)ptes[i].dma_addr,
					(void *)page_to_pfn(page),
					(void *)page_to_phys(page));

/* clean up */
				if (gasket_release_page(ptes[i].page))
					--pg_tbl->num_active_pages;

memset(&ptes[i], 0, sizeof(struct gasket_page_table_entry));
				return -EINVAL;
			}
		}

/* Make the DMA-space address available to the device. */
		dma_addr = (ptes[i].dma_addr + offset) | GASKET_VALID_SLOT_FLAG;

if (is_simple_mapping)
			writeq(dma_addr, &slots[i]);
		else
			((u64 __force *)slots)[i] = dma_addr;

/* Set PTE flags equal to flags param with STATUS=PTE_INUSE. */
		ptes[i].flags = SET(FLAGS_STATUS, flags, PTE_INUSE);
	}
	return 0;
}

/*
 * Return the index of the page for the address in the simple table.
 * Does not perform validity checking.
 */
static int gasket_simple_page_idx(struct gasket_page_table *pg_tbl,
				  u64 dev_addr)
{
	return (dev_addr >> GASKET_SIMPLE_PAGE_SHIFT) &
		(pg_tbl->config.total_entries - 1);
}

/*
 * Return the level 0 page index for the given address.
 * Does not perform validity checking.
 */
static ulong gasket_extended_lvl0_page_idx(struct gasket_page_table *pg_tbl,
					   u64 dev_addr)
{
	return (dev_addr >> GASKET_EXTENDED_LVL0_SHIFT) &
	       (pg_tbl->config.total_entries - 1);
}

/*
 * Return the level 1 page index for the given address.
 * Does not perform validity checking.
 */
static ulong gasket_extended_lvl1_page_idx(struct gasket_page_table *pg_tbl,
					   u64 dev_addr)
{
	return (dev_addr >> GASKET_EXTENDED_LVL1_SHIFT) &
	       (GASKET_PAGES_PER_SUBTABLE - 1);
}

/*
 * Allocate page table entries in a simple table.
 * The page table mutex must be held by the caller.
 */
static int gasket_alloc_simple_entries(struct gasket_page_table *pg_tbl,
				       u64 dev_addr, uint num_pages)
{
	if (!gasket_is_pte_range_free(pg_tbl->entries +
				      gasket_simple_page_idx(pg_tbl, dev_addr),
				      num_pages))
		return -EBUSY;

return 0;
}

/*
 * Unmap and release mapped pages.
 * The page table mutex must be held by the caller.
 */
static void gasket_perform_unmapping(struct gasket_page_table *pg_tbl,
				     struct gasket_page_table_entry *ptes,
				     u64 __iomem *slots, uint num_pages,
				     int is_simple_mapping)
{
	int i;
	/*
	 * For each page table entry and corresponding entry in the device's
	 * address translation table:
	 */
	for (i = 0; i < num_pages; i++) {
		/* release the address from the device, */
		if (is_simple_mapping)
			writeq(0, &slots[i]);
		else
			((u64 __force *)slots)[i] = 0;

/* release the address from the driver, */
		if (GET(FLAGS_STATUS, ptes[i].flags) == PTE_INUSE) {
			if (ptes[i].page && ptes[i].dma_addr) {
				dma_unmap_page(pg_tbl->device, ptes[i].dma_addr, PAGE_SIZE,
					       GET(FLAGS_DMA_DIRECTION, ptes[i].flags));
			}
			if (gasket_release_page(ptes[i].page))
				--pg_tbl->num_active_pages;
		}

/* and clear the PTE. */
		memset(&ptes[i], 0, sizeof(struct gasket_page_table_entry));
	}
}

/*
 * Unmap and release pages mapped to simple addresses.
 * The page table mutex must be held by the caller.
 */
static void gasket_unmap_simple_pages(struct gasket_page_table *pg_tbl,
				      u64 dev_addr, uint num_pages)
{
	uint slot = gasket_simple_page_idx(pg_tbl, dev_addr);

gasket_perform_unmapping(pg_tbl, pg_tbl->entries + slot,
				 pg_tbl->base_slot + slot, num_pages, 1);
}

/*
 * Unmap and release buffers to extended addresses.
 * The page table mutex must be held by the caller.
 */
static void gasket_unmap_extended_pages(struct gasket_page_table *pg_tbl,
					u64 dev_addr, uint num_pages)
{
	uint slot_idx, remain, len;
	struct gasket_page_table_entry *pte;
	u64 __iomem *slot_base;

remain = num_pages;
	slot_idx = gasket_extended_lvl1_page_idx(pg_tbl, dev_addr);
	pte = pg_tbl->entries + pg_tbl->num_simple_entries +
	      gasket_extended_lvl0_page_idx(pg_tbl, dev_addr);

while (remain > 0) {
		/* TODO: Add check to ensure pte remains valid? */
		len = min(remain, GASKET_PAGES_PER_SUBTABLE - slot_idx);

if (GET(FLAGS_STATUS, pte->flags) == PTE_INUSE) {
			slot_base = (u64 __iomem *)(page_address(pte->page) +
						    pte->offset);
			gasket_perform_unmapping(pg_tbl,
						 pte->sublevel + slot_idx,
						 slot_base + slot_idx, len, 0);
			/*
			 * Extended page tables are in DRAM so they need to be
			 * synced each time they are updated.
			 */
			dma_sync_single_for_device(pg_tbl->device,
						   pte->dma_addr + slot_idx * sizeof(u64),
						   len * sizeof(u64), DMA_TO_DEVICE);
		}

remain -= len;
		slot_idx = 0;
		pte++;
	}
}

/* Evaluates to nonzero if the specified virtual address is simple. */
static inline bool gasket_addr_is_simple(struct gasket_page_table *pg_tbl,
					 u64 addr)
{
	return !((addr) & (pg_tbl)->extended_flag);
}

/*
 * Convert (simple, page, offset) into a device address.
 * Examples:
 * Simple page 0, offset 32:
 *  Input (1, 0, 32), Output 0x20
 * Simple page 1000, offset 511:
 *  Input (1, 1000, 511), Output 0x3E81FF
 * Extended page 0, offset 32:
 *  Input (0, 0, 32), Output 0x8000000020
 * Extended page 1000, offset 511:
 *  Input (0, 1000, 511), Output 0x8003E81FF
 */
static u64 gasket_components_to_dev_address(struct gasket_page_table *pg_tbl,
					      int is_simple, uint page_index,
					      uint offset)
{
	u64 dev_addr = (page_index << GASKET_SIMPLE_PAGE_SHIFT) | offset;

return is_simple ? dev_addr : (pg_tbl->extended_flag | dev_addr);
}

/*
 * Validity checking for simple addresses.
 *
 * Verify that address translation commutes (from address to/from page + offset)
 * and that the requested page range starts and ends within the set of
 * currently-partitioned simple pages.
 */
static bool gasket_is_simple_dev_addr_bad(struct gasket_page_table *pg_tbl,
					  u64 dev_addr, uint num_pages)
{
	ulong page_offset = dev_addr & (PAGE_SIZE - 1);
	ulong page_index =
		(dev_addr / PAGE_SIZE) & (pg_tbl->config.total_entries - 1);

if (gasket_components_to_dev_address(pg_tbl, 1, page_index,
					     page_offset) != dev_addr) {
		dev_err(pg_tbl->device, "address is invalid, 0x%llX\n",
			dev_addr);
		return true;
	}

if (page_index >= pg_tbl->num_simple_entries) {
		dev_err(pg_tbl->device,
			"starting slot at %lu is too large, max is < %u\n",
			page_index, pg_tbl->num_simple_entries);
		return true;
	}

if (page_index + num_pages > pg_tbl->num_simple_entries) {
		dev_err(pg_tbl->device,
			"ending slot at %lu is too large, max is <= %u\n",
			page_index + num_pages, pg_tbl->num_simple_entries);
		return true;
	}

return false;
}

/*
 * Validity checking for extended addresses.
 *
 * Verify that address translation commutes (from address to/from page +
 * offset) and that the requested page range starts and ends within the set of
 * currently-partitioned extended pages.
 */
static bool gasket_is_extended_dev_addr_bad(struct gasket_page_table *pg_tbl,
					    u64 dev_addr, uint num_pages)
{
	/* Starting byte index of dev_addr into the first mapped page */
	ulong page_offset = dev_addr & (PAGE_SIZE - 1);
	ulong page_global_idx, page_lvl0_idx;
	ulong num_lvl0_pages;
	u64 addr;

/* check if the device address is out of bound */
	addr = dev_addr & ~((pg_tbl)->extended_flag);
	if (addr >> (GASKET_EXTENDED_LVL0_WIDTH + GASKET_EXTENDED_LVL0_SHIFT)) {
		dev_err(pg_tbl->device,
			"device address out of bounds: 0x%llx\n", dev_addr);
		return true;
	}

/* Find the starting sub-page index in the space of all sub-pages. */
	page_global_idx = (dev_addr / PAGE_SIZE) &
		(pg_tbl->config.total_entries * GASKET_PAGES_PER_SUBTABLE - 1);

/* Find the starting level 0 index. */
	page_lvl0_idx = gasket_extended_lvl0_page_idx(pg_tbl, dev_addr);

/* Get the count of affected level 0 pages. */
	num_lvl0_pages = (num_pages + GASKET_PAGES_PER_SUBTABLE - 1) /
		GASKET_PAGES_PER_SUBTABLE;

if (gasket_components_to_dev_address(pg_tbl, 0, page_global_idx,
					     page_offset) != dev_addr) {
		dev_err(pg_tbl->device, "address is invalid: 0x%llx\n",
			dev_addr);
		return true;
	}

if (page_lvl0_idx >= pg_tbl->num_extended_entries) {
		dev_err(pg_tbl->device,
			"starting level 0 slot at %lu is too large, max is < "
			"%u\n", page_lvl0_idx, pg_tbl->num_extended_entries);
		return true;
	}

if (page_lvl0_idx + num_lvl0_pages > pg_tbl->num_extended_entries) {
		dev_err(pg_tbl->device,
			"ending level 0 slot at %lu is too large, max is <= %u\n",
			page_lvl0_idx + num_lvl0_pages,
			pg_tbl->num_extended_entries);
		return true;
	}

return false;
}

/*
 * Non-locking entry to unmapping routines.
 * The page table mutex must be held by the caller.
 */
static void gasket_page_table_unmap_nolock(struct gasket_page_table *pg_tbl,
					   u64 dev_addr, uint num_pages)
{
	if (!num_pages)
		return;

if (gasket_addr_is_simple(pg_tbl, dev_addr))
		gasket_unmap_simple_pages(pg_tbl, dev_addr, num_pages);
	else
		gasket_unmap_extended_pages(pg_tbl, dev_addr, num_pages);
}

/*
 * Allocate and map pages to simple addresses.
 * If there is an error, no pages are mapped.
 */
static int gasket_map_simple_pages(struct gasket_page_table *pg_tbl,
				   struct sg_page_iter *sg_iter,
				   ulong host_addr, u64 dev_addr,
				   uint num_pages, u32 flags)
{
	int ret;
	uint slot_idx = gasket_simple_page_idx(pg_tbl, dev_addr);

ret = gasket_alloc_simple_entries(pg_tbl, dev_addr, num_pages);
	if (ret) {
		dev_err(pg_tbl->device,
			"page table slots %u (@ 0x%llx) to %u are not available\n",
			slot_idx, (long long unsigned int)dev_addr,
			slot_idx + num_pages - 1);
		return ret;
	}

ret = gasket_perform_mapping(pg_tbl, pg_tbl->entries + slot_idx,
				     pg_tbl->base_slot + slot_idx, sg_iter,
				     host_addr, num_pages, flags, 1);

if (ret) {
		gasket_page_table_unmap_nolock(pg_tbl, dev_addr, num_pages);
		dev_err(pg_tbl->device, "gasket_perform_mapping %d\n", ret);
	}
	return ret;
}

/*
 * Allocate a second level page table.
 * The page table mutex must be held by the caller.
 */
static int gasket_alloc_extended_subtable(struct gasket_page_table *pg_tbl,
					  struct gasket_page_table_entry *pte,
					  u64 __iomem *slot)
{
	ulong page_addr, subtable_bytes;
	dma_addr_t dma_addr;

/* XXX FIX ME XXX this is inefficient for non-4K page sizes */

/* GFP_DMA flag must be passed to architectures for which
	 * part of the memory range is not considered DMA'able.
	 * This seems to be the case for Juno board with 4.5.0 Linaro kernel
	 */
	page_addr = get_zeroed_page(GFP_KERNEL | GFP_DMA);
	if (!page_addr)
		return -ENOMEM;
	pte->page = virt_to_page((void *)page_addr);
	pte->offset = 0;

subtable_bytes = sizeof(struct gasket_page_table_entry) *
		GASKET_PAGES_PER_SUBTABLE;
	pte->sublevel = vzalloc(subtable_bytes);
	if (!pte->sublevel) {
		free_page(page_addr);
		memset(pte, 0, sizeof(struct gasket_page_table_entry));
		return -ENOMEM;
	}

/* Map the page into DMA space. */
	pte->dma_addr = dma_map_page(pg_tbl->device, pte->page, 0, PAGE_SIZE,
				     DMA_TO_DEVICE);
	if (dma_mapping_error(pg_tbl->device, pte->dma_addr)) {
		dev_dbg(pg_tbl->device,
			"%s -> fail to map page %llx "
			"[pfn %p phys %p]\n",
			__func__,
			(unsigned long long)pte->dma_addr,
			(void *)page_to_pfn(pte->page),
			(void *)page_to_phys(pte->page));

/* clean up */
		free_page(page_addr);
		vfree(pte->sublevel);
		memset(pte, 0, sizeof(struct gasket_page_table_entry));

return -ENOMEM;
	}

/* make the addresses available to the device */
	dma_addr = (pte->dma_addr + pte->offset) | GASKET_VALID_SLOT_FLAG;
	writeq(dma_addr, slot);

pte->flags = SET(FLAGS_STATUS, pte->flags, PTE_INUSE);

return 0;
}

/*
 * Allocate slots in an extended page table.  Check to see if a range of page
 * table slots are available. If necessary, memory is allocated for second level
 * page tables.
 *
 * Note that memory for second level page tables is allocated as needed, but
 * that memory is only freed on the final close	of the device file, when the
 * page tables are repartitioned, or the the device is removed.  If there is an
 * error or if the full range of slots is not available, any memory
 * allocated for second level page tables remains allocated until final close,
 * repartition, or device removal.
 *
 * The page table mutex must be held by the caller.
 */
static int gasket_alloc_extended_entries(struct gasket_page_table *pg_tbl,
					 u64 dev_addr, uint num_entries)
{
	int ret = 0;
	uint remain, subtable_slot_idx, len;
	struct gasket_page_table_entry *pte;
	u64 __iomem *slot;

remain = num_entries;
	subtable_slot_idx = gasket_extended_lvl1_page_idx(pg_tbl, dev_addr);
	pte = pg_tbl->entries + pg_tbl->num_simple_entries +
	      gasket_extended_lvl0_page_idx(pg_tbl, dev_addr);
	slot = pg_tbl->base_slot + pg_tbl->num_simple_entries +
	       gasket_extended_lvl0_page_idx(pg_tbl, dev_addr);

while (remain > 0) {
		len = min(remain,
			  GASKET_PAGES_PER_SUBTABLE - subtable_slot_idx);

if (GET(FLAGS_STATUS, pte->flags) == PTE_FREE) {
			ret = gasket_alloc_extended_subtable(pg_tbl, pte, slot);
			if (ret) {
				dev_err(pg_tbl->device,
					"no memory for extended addr subtable\n");
				return ret;
			}
		} else {
			if (!gasket_is_pte_range_free(pte->sublevel +
						      subtable_slot_idx, len))
				return -EBUSY;
		}

remain -= len;
		subtable_slot_idx = 0;
		pte++;
		slot++;
	}

return 0;
}

/*
 * gasket_map_extended_pages - Get and map buffers to extended addresses.
 * If there is an error, no pages are mapped.
 */
static int gasket_map_extended_pages(struct gasket_page_table *pg_tbl,
				     struct sg_page_iter *sg_iter,
				     ulong host_addr, u64 dev_addr,
				     uint num_pages, u32 flags)
{
	int ret;
	u64 dev_addr_end;
	uint slot_idx, remain, len;
	struct gasket_page_table_entry *pte;
	u64 __iomem *slot_base;

ret = gasket_alloc_extended_entries(pg_tbl, dev_addr, num_pages);
	if (ret) {
		dev_addr_end = dev_addr + (num_pages / PAGE_SIZE) - 1;
		dev_err(pg_tbl->device,
			"page table slots (%lu,%lu) (@ 0x%llx) to (%lu,%lu) "
			"are not available\n",
			gasket_extended_lvl0_page_idx(pg_tbl, dev_addr),
			gasket_extended_lvl1_page_idx(pg_tbl, dev_addr),
			(long long unsigned int)dev_addr,
			gasket_extended_lvl0_page_idx(pg_tbl, dev_addr_end),
			gasket_extended_lvl1_page_idx(pg_tbl, dev_addr_end));
		return ret;
	}

remain = num_pages;
	slot_idx = gasket_extended_lvl1_page_idx(pg_tbl, dev_addr);
	pte = pg_tbl->entries + pg_tbl->num_simple_entries +
	      gasket_extended_lvl0_page_idx(pg_tbl, dev_addr);

while (remain > 0) {
		len = min(remain, GASKET_PAGES_PER_SUBTABLE - slot_idx);

slot_base =
			(u64 __iomem *)(page_address(pte->page) + pte->offset);
		ret = gasket_perform_mapping(pg_tbl, pte->sublevel + slot_idx,
					     slot_base + slot_idx, sg_iter,
					     host_addr, len, flags, 0);
		if (ret) {
			gasket_page_table_unmap_nolock(pg_tbl, dev_addr,
						       num_pages);
			return ret;
		}

/*
		 * Extended page tables are in DRAM so they need to be synced
		 * each time they are updated.
		 */
		dma_sync_single_for_device(pg_tbl->device,
					   pte->dma_addr + slot_idx * sizeof(u64),
					   len * sizeof(u64), DMA_TO_DEVICE);

remain -= len;
		slot_idx = 0;
		pte++;
		if (host_addr)
			host_addr += len * PAGE_SIZE;
	}

return 0;
}

/*
 * See gasket_page_table.h for general description.
 *
 * gasket_page_table_map calls either gasket_map_simple_pages() or
 * gasket_map_extended_pages() to actually perform the mapping.
 *
 * The page table mutex is held for the entire operation.
 */
int gasket_page_table_map(struct gasket_page_table *pg_tbl, ulong host_addr,
			  u64 dev_addr, uint num_pages, u32 flags)
{
	int ret;

if (!num_pages)
		return 0;

mutex_lock(&pg_tbl->mutex);

if (gasket_addr_is_simple(pg_tbl, dev_addr)) {
		ret = gasket_map_simple_pages(pg_tbl, NULL, host_addr, dev_addr,
					      num_pages, flags);
	} else {
		ret = gasket_map_extended_pages(pg_tbl, NULL, host_addr, dev_addr,
						num_pages, flags);
	}

mutex_unlock(&pg_tbl->mutex);

dev_dbg(pg_tbl->device,
		"%s done: ha %llx daddr %llx num %d, flags %x ret %d\n",
		__func__, (unsigned long long)host_addr,
		(unsigned long long)dev_addr, num_pages, flags, ret);
	return ret;
}
EXPORT_SYMBOL(gasket_page_table_map);

/*
 * See gasket_page_table.h for general description.
 *
 * gasket_page_table_unmap takes the page table lock and calls either
 * gasket_unmap_simple_pages() or gasket_unmap_extended_pages() to
 * actually unmap the pages from device space.
 *
 * The page table mutex is held for the entire operation.
 */
void gasket_page_table_unmap(struct gasket_page_table *pg_tbl, u64 dev_addr,
			     uint num_pages)
{
	if (!num_pages)
		return;

mutex_lock(&pg_tbl->mutex);
	gasket_page_table_unmap_nolock(pg_tbl, dev_addr, num_pages);
	mutex_unlock(&pg_tbl->mutex);
}
EXPORT_SYMBOL(gasket_page_table_unmap);

int gasket_page_table_map_dmabuf(struct gasket_page_table *pg_tbl, int fd,
				 u64 dev_addr, uint num_pages, u32 flags)
{
	int ret, locked = 0;
	struct dma_buf *dmabuf = NULL;
	struct dma_buf_attachment *attachment = NULL;
	struct sg_table *sgt = NULL;
	struct sg_page_iter sg_iter;
	struct gasket_dmabuf_mapping *mapping = NULL;
	enum dma_data_direction direction = GET(FLAGS_DMA_DIRECTION, flags);

if (direction == DMA_NONE) {
		dev_err(pg_tbl->device,
			"invalid DMA direction flags=0x%x\n", flags);
		return -EINVAL;
	}

if (!num_pages)
		return 0;

dmabuf = dma_buf_get(fd);
	if (IS_ERR(dmabuf))
		return PTR_ERR(dmabuf);

if (PAGE_ALIGN(dmabuf->size) / PAGE_SIZE < num_pages)
		return -EINVAL;

mapping = kzalloc(sizeof(*mapping), GFP_KERNEL);
	if (!mapping) {
		ret = -ENOMEM;
		goto out;
	}

attachment = dma_buf_attach(dmabuf, pg_tbl->device);
	if (IS_ERR(attachment)) {
		ret = PTR_ERR(attachment);
		goto out;
	}

sgt = dma_buf_map_attachment(attachment, direction);
	if (IS_ERR(sgt)) {
		ret = PTR_ERR(sgt);
		goto out;
	}

mutex_lock(&pg_tbl->mutex);
	locked = 1;

__sg_page_iter_start(&sg_iter, sgt->sgl, sgt->nents, 0);
	if (gasket_addr_is_simple(pg_tbl, dev_addr)) {
		ret = gasket_map_simple_pages(pg_tbl, &sg_iter, 0, dev_addr,
					      num_pages, flags);
	} else {
		ret = gasket_map_extended_pages(pg_tbl, &sg_iter, 0, dev_addr,
						num_pages, flags);
	}

if (!ret) {
		INIT_LIST_HEAD(&mapping->list);
		get_dma_buf(dmabuf);
		mapping->dmabuf = dmabuf;
		mapping->attachment = attachment;
		mapping->sgt = sgt;
		mapping->direction = direction;
		list_add(&mapping->list, &pg_tbl->dmabufs);
		sgt = NULL;
		attachment = NULL;
		mapping = NULL;
	}

out:
	if (locked)
		mutex_unlock(&pg_tbl->mutex);

if (!IS_ERR_OR_NULL(sgt))
		dma_buf_unmap_attachment(attachment, sgt, direction);

if (!IS_ERR_OR_NULL(attachment))
		dma_buf_detach(dmabuf, attachment);

kfree(mapping);
	dma_buf_put(dmabuf);

return ret;
}
EXPORT_SYMBOL(gasket_page_table_map_dmabuf);

/* Detach dmabuf from our device if attached, NULL to detach all. */
static void gasket_page_table_detach_dmabuf_nolock(struct gasket_page_table *pg_tbl,
						   struct dma_buf *dmabuf)
{
	struct gasket_dmabuf_mapping *mapping, *tmp;

list_for_each_entry_safe(mapping, tmp, &pg_tbl->dmabufs, list) {
		if (!dmabuf || mapping->dmabuf == dmabuf) {
			dma_buf_unmap_attachment(mapping->attachment,
						 mapping->sgt,
						 mapping->direction);
			dma_buf_detach(mapping->dmabuf, mapping->attachment);
			dma_buf_put(mapping->dmabuf);
			list_del(&mapping->list);
			kfree(mapping);
		}
	}
}

int gasket_page_table_unmap_dmabuf(struct gasket_page_table *pg_tbl, int fd,
				   u64 dev_addr, uint num_pages)
{
	struct dma_buf *dmabuf;

dmabuf = dma_buf_get(fd);
	if (IS_ERR(dmabuf))
		return PTR_ERR(dmabuf);

if (PAGE_ALIGN(dmabuf->size) / PAGE_SIZE < num_pages) {
		dma_buf_put(dmabuf);
		return -EINVAL;
	}

mutex_lock(&pg_tbl->mutex);

gasket_page_table_unmap_nolock(pg_tbl, dev_addr, num_pages);
	gasket_page_table_detach_dmabuf_nolock(pg_tbl, dmabuf);

mutex_unlock(&pg_tbl->mutex);

dma_buf_put(dmabuf);

return 0;
}
EXPORT_SYMBOL(gasket_page_table_unmap_dmabuf);

static void gasket_page_table_unmap_all_nolock(struct gasket_page_table *pg_tbl)
{
	gasket_page_table_detach_dmabuf_nolock(pg_tbl, NULL);

gasket_unmap_simple_pages(pg_tbl,
				  gasket_components_to_dev_address(pg_tbl, 1, 0,
								   0),
				  pg_tbl->num_simple_entries);
	gasket_unmap_extended_pages(pg_tbl,
				    gasket_components_to_dev_address(pg_tbl, 0,
								     0, 0),
				    pg_tbl->num_extended_entries *
				    GASKET_PAGES_PER_SUBTABLE);
}

/* See gasket_page_table.h for description. */
void gasket_page_table_unmap_all(struct gasket_page_table *pg_tbl)
{
	mutex_lock(&pg_tbl->mutex);
	gasket_page_table_unmap_all_nolock(pg_tbl);
	mutex_unlock(&pg_tbl->mutex);
}
EXPORT_SYMBOL(gasket_page_table_unmap_all);

/* See gasket_page_table.h for description. */
void gasket_page_table_reset(struct gasket_page_table *pg_tbl)
{
	mutex_lock(&pg_tbl->mutex);
	gasket_page_table_unmap_all_nolock(pg_tbl);
	writeq(pg_tbl->config.total_entries, pg_tbl->extended_offset_reg);
	mutex_unlock(&pg_tbl->mutex);
}

/* See gasket_page_table.h for description. */
int gasket_page_table_lookup_page(
	struct gasket_page_table *pg_tbl, u64 dev_addr, struct page **ppage,
	ulong *poffset)
{
	uint page_num;
	struct gasket_page_table_entry *pte;

mutex_lock(&pg_tbl->mutex);
	if (gasket_addr_is_simple(pg_tbl, dev_addr)) {
		page_num = gasket_simple_page_idx(pg_tbl, dev_addr);
		if (page_num >= pg_tbl->num_simple_entries)
			goto fail;

pte = pg_tbl->entries + page_num;
		if (GET(FLAGS_STATUS, pte->flags) != PTE_INUSE)
			goto fail;
	} else {
		/* Find the level 0 entry, */
		page_num = gasket_extended_lvl0_page_idx(pg_tbl, dev_addr);
		if (page_num >= pg_tbl->num_extended_entries)
			goto fail;

pte = pg_tbl->entries + pg_tbl->num_simple_entries + page_num;
		if (GET(FLAGS_STATUS, pte->flags) != PTE_INUSE)
			goto fail;

/* and its contained level 1 entry. */
		page_num = gasket_extended_lvl1_page_idx(pg_tbl, dev_addr);
		pte = pte->sublevel + page_num;
		if (GET(FLAGS_STATUS, pte->flags) != PTE_INUSE)
			goto fail;
	}

*ppage = pte->page;
	*poffset = pte->offset;
	mutex_unlock(&pg_tbl->mutex);
	return 0;

fail:
	*ppage = NULL;
	*poffset = 0;
	mutex_unlock(&pg_tbl->mutex);
	return -EINVAL;
}

/* See gasket_page_table.h for description. */
bool gasket_page_table_are_addrs_bad(
	struct gasket_page_table *pg_tbl, ulong host_addr, u64 dev_addr,
	ulong bytes)
{
	if (host_addr & (PAGE_SIZE - 1)) {
		dev_err(pg_tbl->device,
			"host mapping address 0x%lx must be page aligned\n",
			host_addr);
		return true;
	}

return gasket_page_table_is_dev_addr_bad(pg_tbl, dev_addr, bytes);
}
EXPORT_SYMBOL(gasket_page_table_are_addrs_bad);

/* See gasket_page_table.h for description. */
bool gasket_page_table_is_dev_addr_bad(
	struct gasket_page_table *pg_tbl, u64 dev_addr, ulong bytes)
{
	uint num_pages = bytes / PAGE_SIZE;

if (bytes & (PAGE_SIZE - 1)) {
		dev_err(pg_tbl->device,
			"mapping size 0x%lX must be page aligned\n", bytes);
		return true;
	}

if (num_pages == 0) {
		dev_err(pg_tbl->device,
			"requested mapping is less than one page: %lu / %lu\n",
			bytes, PAGE_SIZE);
		return true;
	}

if (gasket_addr_is_simple(pg_tbl, dev_addr))
		return gasket_is_simple_dev_addr_bad(pg_tbl, dev_addr,
						     num_pages);
	return gasket_is_extended_dev_addr_bad(pg_tbl, dev_addr, num_pages);
}
EXPORT_SYMBOL(gasket_page_table_is_dev_addr_bad);

/* See gasket_page_table.h for description. */
uint gasket_page_table_max_size(struct gasket_page_table *page_table)
{
	if (!page_table)
		return 0;
	return page_table->config.total_entries;
}
EXPORT_SYMBOL(gasket_page_table_max_size);

/* See gasket_page_table.h for description. */
uint gasket_page_table_num_entries(struct gasket_page_table *pg_tbl)
{
	if (!pg_tbl)
		return 0;
	return pg_tbl->num_simple_entries + pg_tbl->num_extended_entries;
}
EXPORT_SYMBOL(gasket_page_table_num_entries);

/* See gasket_page_table.h for description. */
uint gasket_page_table_num_simple_entries(struct gasket_page_table *pg_tbl)
{
	if (!pg_tbl)
		return 0;
	return pg_tbl->num_simple_entries;
}
EXPORT_SYMBOL(gasket_page_table_num_simple_entries);

/* See gasket_page_table.h for description. */
uint gasket_page_table_num_active_pages(struct gasket_page_table *pg_tbl)
{
	if (!pg_tbl)
		return 0;
	return pg_tbl->num_active_pages;
}
EXPORT_SYMBOL(gasket_page_table_num_active_pages);

/* See gasket_page_table.h */
int gasket_page_table_system_status(struct gasket_page_table *page_table)
{
	if (!page_table)
		return GASKET_STATUS_LAMED;

if (gasket_page_table_num_entries(page_table) == 0) {
		dev_dbg(page_table->device, "Page table size is 0\n");
		return GASKET_STATUS_LAMED;
	}

return GASKET_STATUS_ALIVE;
}

/* Record the host_addr to coherent dma memory mapping. */
int gasket_set_user_virt(
	struct gasket_dev *gasket_dev, u64 size, dma_addr_t dma_address,
	ulong vma)
{
	int j;
	struct gasket_page_table *pg_tbl;

unsigned int num_pages = size / PAGE_SIZE;

/*
	 * TODO: for future chipset, better handling of the case where multiple
	 * page tables are supported on a given device
	 */
	pg_tbl = gasket_dev->page_table[0];
	if (!pg_tbl) {
		dev_dbg(gasket_dev->dev, "%s: invalid page table index\n",
			__func__);
		return 0;
	}
	for (j = 0; j < num_pages; j++) {
		pg_tbl->coherent_pages[j].user_virt =
			(u64)vma + j * PAGE_SIZE;
	}
	return 0;
}

/* Allocate a block of coherent memory. */
int gasket_alloc_coherent_memory(struct gasket_dev *gasket_dev, u64 size,
				 dma_addr_t *dma_address, u64 index)
{
	dma_addr_t handle;
	void *mem;
	int j;
	unsigned int num_pages = (size + PAGE_SIZE - 1) / PAGE_SIZE;
	const struct gasket_driver_desc *driver_desc =
		gasket_get_driver_desc(gasket_dev);

if (!gasket_dev->page_table[index])
		return -EFAULT;

if (num_pages == 0)
		return -EINVAL;

mem = dma_alloc_coherent(gasket_get_device(gasket_dev),
				 num_pages * PAGE_SIZE, &handle, GFP_KERNEL);
	if (!mem)
		goto nomem;

gasket_dev->page_table[index]->num_coherent_pages = num_pages;

/* allocate the physical memory block */
	gasket_dev->page_table[index]->coherent_pages =
		kcalloc(num_pages, sizeof(struct gasket_coherent_page_entry),
			GFP_KERNEL);
	if (!gasket_dev->page_table[index]->coherent_pages)
		goto nomem;

gasket_dev->coherent_buffer.length_bytes =
		PAGE_SIZE * (num_pages);
	gasket_dev->coherent_buffer.phys_base = handle;
	gasket_dev->coherent_buffer.virt_base = mem;

*dma_address = driver_desc->coherent_buffer_description.base;
	for (j = 0; j < num_pages; j++) {
		gasket_dev->page_table[index]->coherent_pages[j].paddr =
			handle + j * PAGE_SIZE;
		gasket_dev->page_table[index]->coherent_pages[j].kernel_virt =
			(ulong)mem + j * PAGE_SIZE;
	}

return 0;

nomem:
	if (mem) {
		dma_free_coherent(gasket_get_device(gasket_dev),
				  num_pages * PAGE_SIZE, mem, handle);
		gasket_dev->coherent_buffer.length_bytes = 0;
		gasket_dev->coherent_buffer.virt_base = NULL;
		gasket_dev->coherent_buffer.phys_base = 0;
	}

kfree(gasket_dev->page_table[index]->coherent_pages);
	gasket_dev->page_table[index]->coherent_pages = NULL;
	gasket_dev->page_table[index]->num_coherent_pages = 0;
	return -ENOMEM;
}

/* Free a block of coherent memory. */
int gasket_free_coherent_memory(struct gasket_dev *gasket_dev, u64 size,
				dma_addr_t dma_address, u64 index)
{
	const struct gasket_driver_desc *driver_desc;

if (!gasket_dev->page_table[index])
		return -EFAULT;

driver_desc = gasket_get_driver_desc(gasket_dev);

if (driver_desc->coherent_buffer_description.base != dma_address)
		return -EADDRNOTAVAIL;

gasket_free_coherent_memory_all(gasket_dev, index);

return 0;
}

/* Release all coherent memory. */
void gasket_free_coherent_memory_all(
	struct gasket_dev *gasket_dev, u64 index)
{
	if (!gasket_dev->page_table[index])
		return;

if (gasket_dev->coherent_buffer.length_bytes) {
		dma_free_coherent(gasket_get_device(gasket_dev),
				  gasket_dev->coherent_buffer.length_bytes,
				  gasket_dev->coherent_buffer.virt_base,
				  gasket_dev->coherent_buffer.phys_base);
		gasket_dev->coherent_buffer.length_bytes = 0;
		gasket_dev->coherent_buffer.virt_base = NULL;
		gasket_dev->coherent_buffer.phys_base = 0;
	}

kfree(gasket_dev->page_table[index]->coherent_pages);
	gasket_dev->page_table[index]->coherent_pages = NULL;
	gasket_dev->page_table[index]->num_coherent_pages = 0;
}
0707010000001B000081A40000000000000000000000016217DF4F0000293C000000000000000000000000000000000000002D00000000gasket-driver-1.0.18/src/gasket_page_table.h/* SPDX-License-Identifier: GPL-2.0 */
/*
 * Gasket Page Table functionality. This file describes the address
 * translation/paging functionality supported by the Gasket driver framework.
 * As much as possible, internal details are hidden to simplify use -
 * all calls are thread-safe (protected by an internal mutex) except where
 * indicated otherwise.
 *
 * Copyright (C) 2018 Google, Inc.
 */

#ifndef __GASKET_PAGE_TABLE_H__
#define __GASKET_PAGE_TABLE_H__

#include <linux/pci.h>
#include <linux/types.h>

#include "gasket_constants.h"
#include "gasket_core.h"

/*
 * Structure used for managing address translation on a device. All details are
 * internal to the implementation.
 */
struct gasket_page_table;

/*
 * Allocate and init address translation data.
 * @ppage_table: Pointer to Gasket page table pointer. Set by this call.
 * @att_base_reg: [Mapped] pointer to the first entry in the device's address
 *                translation table.
 * @extended_offset_reg: [Mapped] pointer to the device's register containing
 *                       the starting index of the extended translation table.
 * @extended_bit_location: The index of the bit indicating whether an address
 *                         is extended.
 * @total_entries: The total number of entries in the device's address
 *                 translation table.
 * @device: Device structure for the underlying device. Only used for logging.
 * @pci_dev: PCI system descriptor for the underlying device.
 * whether the driver will supply its own.
 *
 * Description: Allocates and initializes data to track address translation -
 * simple and extended page table metadata. Initially, the page table is
 * partitioned such that all addresses are "simple" (single-level lookup).
 * gasket_partition_page_table can be called to change this paritioning.
 *
 * Returns 0 on success, a negative error code otherwise.
 */
int gasket_page_table_init(struct gasket_page_table **ppg_tbl,
			   const struct gasket_bar_data *bar_data,
			   const struct gasket_page_table_config *page_table_config,
			   struct device *device, struct pci_dev *pci_dev);

/*
 * Deallocate and cleanup page table data.
 * @page_table: Gasket page table pointer.
 *
 * Description: The inverse of gasket_init; frees page_table and its contained
 *              elements.
 *
 *	        Because this call destroys the page table, it cannot be
 *	        thread-safe (mutex-protected)!
 */
void gasket_page_table_cleanup(struct gasket_page_table *page_table);

/*
 * Sets the size of the simple page table.
 * @page_table: Gasket page table pointer.
 * @num_simple_entries: Desired size of the simple page table (in entries).
 *
 * Description: gasket_partition_page_table checks to see if the simple page
 *              size can be changed (i.e., if there are no active extended
 *              mappings in the new simple size range), and, if so,
 *              sets the new simple and extended page table sizes.
 *
 *              Returns 0 if successful, or non-zero if the page table entries
 *              are not free.
 */
int gasket_page_table_partition(struct gasket_page_table *page_table,
				uint num_simple_entries);

/*
 * Get and map [host] user space pages into device memory.
 * @page_table: Gasket page table pointer.
 * @host_addr: Starting host virtual memory address of the pages.
 * @dev_addr: Starting device address of the pages.
 * @num_pages: Number of [4kB] pages to map.
 * @flags: Specifies attributes to apply to the pages.
 *         Internal structure matches gasket_page_table_ioctl_flags.flags.
 *
 * Description: Maps the "num_pages" pages of host memory pointed to by
 *              host_addr to the address "dev_addr" in device memory.
 *
 *              The caller is responsible for checking the addresses ranges.
 *
 *              Returns 0 if successful or a non-zero error number otherwise.
 *              If there is an error, no pages are mapped.
 */
int gasket_page_table_map(struct gasket_page_table *page_table, ulong host_addr,
			  u64 dev_addr, uint num_pages, u32 flags);

/*
 * Map dma-buf pages into device memory.
 * @page_table: Gasket page table pointer.
 * @fd: Dma-buf file descriptor.
 * @dev_addr: Starting device address of the pages.
 * @num_pages: Number of [4kB] pages to map.
 * @flags: Specifies attributes to apply to the pages.
 *         Internal structure matches gasket_page_table_ioctl_flags.flags.
 *
 * Description: Maps "num_pages" pages of dma-buf pointed to by
 *              fd to the address "dev_addr" in device memory.
 *
 *              The caller is responsible for checking the dev_addr range.
 *
 *              Returns 0 if successful or a non-zero error number otherwise.
 *              If there is an error, no pages are mapped.
 */
int gasket_page_table_map_dmabuf(struct gasket_page_table *page_table, int fd,
				 u64 dev_addr, uint num_pages, u32 flags);

/*
 * Unmap dma-buf pages from device memory.
 * @page_table: Gasket page table pointer.
 * @fd: Dma-buf file descriptor.
 * @dev_addr: Starting device address of the pages.
 * @num_pages: Number of [4kB] pages to map.
 *
 * Description: The inverse of gasket_page_table_map_dmabuf.
 */
int gasket_page_table_unmap_dmabuf(struct gasket_page_table *page_table, int fd,
				   u64 dev_addr, uint num_pages);

/*
 * Un-map host pages from device memory.
 * @page_table: Gasket page table pointer.
 * @dev_addr: Starting device address of the pages to unmap.
 * @num_pages: The number of [4kB] pages to unmap.
 *
 * Description: The inverse of gasket_map_pages. Unmaps pages from the device.
 */
void gasket_page_table_unmap(struct gasket_page_table *page_table,
			     u64 dev_addr, uint num_pages);

/*
 * Unmap ALL host pages from device memory.
 * @page_table: Gasket page table pointer.
 */
void gasket_page_table_unmap_all(struct gasket_page_table *page_table);

/*
 * Unmap all host pages from device memory and reset the table to fully simple
 * addressing.
 * @page_table: Gasket page table pointer.
 */
void gasket_page_table_reset(struct gasket_page_table *page_table);

/*
 * Reclaims unused page table memory.
 * @page_table: Gasket page table pointer.
 *
 * Description: Examines the page table and frees any currently-unused
 *              allocations. Called internally on gasket_cleanup().
 */
void gasket_page_table_garbage_collect(struct gasket_page_table *page_table);

/*
 * Retrieve the backing page for a device address.
 * @page_table: Gasket page table pointer.
 * @dev_addr: Gasket device address.
 * @ppage: Pointer to a page pointer for the returned page.
 * @poffset: Pointer to an unsigned long for the returned offset.
 *
 * Description: Interprets the address and looks up the corresponding page
 *              in the page table and the offset in that page.  (We need an
 *              offset because the host page may be larger than the Gasket chip
 *              page it contains.)
 *
 *              Returns 0 if successful, -1 for an error.  The page pointer
 *              and offset are returned through the pointers, if successful.
 */
int gasket_page_table_lookup_page(struct gasket_page_table *page_table,
				  u64 dev_addr, struct page **page,
				  ulong *poffset);

/*
 * Checks validity for input addrs and size.
 * @page_table: Gasket page table pointer.
 * @host_addr: Host address to check.
 * @dev_addr: Gasket device address.
 * @bytes: Size of the range to check (in bytes).
 *
 * Description: This call performs a number of checks to verify that the ranges
 * specified by both addresses and the size are valid for mapping pages into
 * device memory.
 *
 * Returns true if the mapping is bad, false otherwise.
 */
bool gasket_page_table_are_addrs_bad(struct gasket_page_table *page_table,
				     ulong host_addr, u64 dev_addr,
				     ulong bytes);

/*
 * Checks validity for input dev addr and size.
 * @page_table: Gasket page table pointer.
 * @dev_addr: Gasket device address.
 * @bytes: Size of the range to check (in bytes).
 *
 * Description: This call performs a number of checks to verify that the range
 * specified by the device address and the size is valid for mapping pages into
 * device memory.
 *
 * Returns true if the address is bad, false otherwise.
 */
bool gasket_page_table_is_dev_addr_bad(struct gasket_page_table *page_table,
				       u64 dev_addr, ulong bytes);

/*
 * Gets maximum size for the given page table.
 * @page_table: Gasket page table pointer.
 */
uint gasket_page_table_max_size(struct gasket_page_table *page_table);

/*
 * Gets the total number of entries in the arg.
 * @page_table: Gasket page table pointer.
 */
uint gasket_page_table_num_entries(struct gasket_page_table *page_table);

/*
 * Gets the number of simple entries.
 * @page_table: Gasket page table pointer.
 */
uint gasket_page_table_num_simple_entries(struct gasket_page_table *page_table);

/*
 * Gets the number of actively pinned pages.
 * @page_table: Gasket page table pointer.
 */
uint gasket_page_table_num_active_pages(struct gasket_page_table *page_table);

/*
 * Get status of page table managed by @page_table.
 * @page_table: Gasket page table pointer.
 */
int gasket_page_table_system_status(struct gasket_page_table *page_table);

/*
 * Allocate a block of coherent memory.
 * @gasket_dev: Gasket Device.
 * @size: Size of the memory block.
 * @dma_address: Dma address allocated by the kernel.
 * @index: Index of the gasket_page_table within this Gasket device
 *
 * Description: Allocate a contiguous coherent memory block, DMA'ble
 * by this device.
 */
int gasket_alloc_coherent_memory(struct gasket_dev *gasket_dev, uint64_t size,
				 dma_addr_t *dma_address, uint64_t index);
/* Release a block of contiguous coherent memory, in use by a device. */
int gasket_free_coherent_memory(struct gasket_dev *gasket_dev, uint64_t size,
				dma_addr_t dma_address, uint64_t index);

/* Release all coherent memory. */
void gasket_free_coherent_memory_all(struct gasket_dev *gasket_dev,
				     uint64_t index);

/*
 * Records the host_addr to coherent dma memory mapping.
 * @gasket_dev: Gasket Device.
 * @size: Size of the virtual address range to map.
 * @dma_address: Dma address within the coherent memory range.
 * @vma: Virtual address we wish to map to coherent memory.
 *
 * Description: For each page in the virtual address range, record the
 * coherent page mapping.
 *
 * Does not perform validity checking.
 */
int gasket_set_user_virt(struct gasket_dev *gasket_dev, uint64_t size,
			 dma_addr_t dma_address, ulong vma);

#endif  /* __GASKET_PAGE_TABLE_H__ */
0707010000001C000081A40000000000000000000000016217DF4F0000282D000000000000000000000000000000000000002800000000gasket-driver-1.0.18/src/gasket_sysfs.c// SPDX-License-Identifier: GPL-2.0
/* Copyright (C) 2018 Google, Inc. */
#include "gasket_sysfs.h"

#include "gasket_core.h"

#include <linux/device.h>
#include <linux/printk.h>

/*
 * Pair of kernel device and user-specified pointer. Used in lookups in sysfs
 * "show" functions to return user data.
 */

struct gasket_sysfs_mapping {
	/*
	 * The device bound to this mapping. If this is NULL, then this mapping
	 * is free.
	 */
	struct device *device;

/* The Gasket descriptor for this device. */
	struct gasket_dev *gasket_dev;

/* This device's set of sysfs attributes/nodes. */
	struct gasket_sysfs_attribute *attributes;

/* The number of live elements in "attributes". */
	int attribute_count;

/* Protects structure from simultaneous access. */
	struct mutex mutex;

/* Tracks active users of this mapping. */
	struct kref refcount;
};

/*
 * Data needed to manage users of this sysfs utility.
 * Currently has a fixed size; if space is a concern, this can be dynamically
 * allocated.
 */
/*
 * 'Global' (file-scoped) list of mappings between devices and gasket_data
 * pointers. This removes the requirement to have a gasket_sysfs_data
 * handle in all files.
 */
static struct gasket_sysfs_mapping dev_mappings[GASKET_SYSFS_NUM_MAPPINGS];

/* Callback when a mapping's refcount goes to zero. */
static void release_entry(struct kref *ref)
{
	/* All work is done after the return from kref_put. */
}

/* Look up mapping information for the given device. */
static struct gasket_sysfs_mapping *get_mapping(struct device *device)
{
	int i;

for (i = 0; i < GASKET_SYSFS_NUM_MAPPINGS; i++) {
		mutex_lock(&dev_mappings[i].mutex);
		if (dev_mappings[i].device == device) {
			kref_get(&dev_mappings[i].refcount);
			mutex_unlock(&dev_mappings[i].mutex);
			return &dev_mappings[i];
		}
		mutex_unlock(&dev_mappings[i].mutex);
	}

dev_dbg(device, "%s: Mapping to device %s not found\n",
		__func__, device->kobj.name);
	return NULL;
}

/* Put a reference to a mapping. */
static void put_mapping(struct gasket_sysfs_mapping *mapping)
{
	int i;
	int num_files_to_remove = 0;
	struct device_attribute *files_to_remove;
	struct device *device;

if (!mapping) {
		pr_debug("%s: Mapping should not be NULL\n", __func__);
		return;
	}

mutex_lock(&mapping->mutex);
	if (kref_put(&mapping->refcount, release_entry)) {
		dev_dbg(mapping->device, "Removing Gasket sysfs mapping\n");
		/*
		 * We can't remove the sysfs nodes in the kref callback, since
		 * device_remove_file() blocks until the node is free.
		 * Readers/writers of sysfs nodes, though, will be blocked on
		 * the mapping mutex, resulting in deadlock. To fix this, the
		 * sysfs nodes are removed outside the lock.
		 */
		device = mapping->device;
		num_files_to_remove = mapping->attribute_count;
		files_to_remove = kcalloc(num_files_to_remove,
					  sizeof(*files_to_remove),
					  GFP_KERNEL);
		if (files_to_remove)
			for (i = 0; i < num_files_to_remove; i++)
				files_to_remove[i] =
				    mapping->attributes[i].attr;
		else
			num_files_to_remove = 0;

kfree(mapping->attributes);
		mapping->attributes = NULL;
		mapping->attribute_count = 0;
		put_device(mapping->device);
		mapping->device = NULL;
		mapping->gasket_dev = NULL;
	}
	mutex_unlock(&mapping->mutex);

if (num_files_to_remove != 0) {
		for (i = 0; i < num_files_to_remove; ++i)
			device_remove_file(device, &files_to_remove[i]);
		kfree(files_to_remove);
	}
}

/*
 * Put a reference to a mapping N times.
 *
 * In higher-level resource acquire/release function pairs, the release function
 * will need to release a mapping 2x - once for the refcount taken in the
 * release function itself, and once for the count taken in the acquire call.
 */
static void put_mapping_n(struct gasket_sysfs_mapping *mapping, int times)
{
	int i;

for (i = 0; i < times; i++)
		put_mapping(mapping);
}

void gasket_sysfs_init(void)
{
	int i;

for (i = 0; i < GASKET_SYSFS_NUM_MAPPINGS; i++) {
		dev_mappings[i].device = NULL;
		mutex_init(&dev_mappings[i].mutex);
	}
}

int gasket_sysfs_create_mapping(struct device *device,
				struct gasket_dev *gasket_dev)
{
	struct gasket_sysfs_mapping *mapping;
	int map_idx = -1;

/*
	 * We need a function-level mutex to protect against the same device
	 * being added [multiple times] simultaneously.
	 */
	static DEFINE_MUTEX(function_mutex);

mutex_lock(&function_mutex);
	dev_dbg(device, "Creating sysfs entries for device\n");

/* Check that the device we're adding hasn't already been added. */
	mapping = get_mapping(device);
	if (mapping) {
		dev_err(device,
			"Attempting to re-initialize sysfs mapping for device\n");
		put_mapping(mapping);
		mutex_unlock(&function_mutex);
		return -EBUSY;
	}

/* Find the first empty entry in the array. */
	for (map_idx = 0; map_idx < GASKET_SYSFS_NUM_MAPPINGS; ++map_idx) {
		mutex_lock(&dev_mappings[map_idx].mutex);
		if (!dev_mappings[map_idx].device)
			/* Break with the mutex held! */
			break;
		mutex_unlock(&dev_mappings[map_idx].mutex);
	}

if (map_idx == GASKET_SYSFS_NUM_MAPPINGS) {
		dev_err(device, "All mappings have been exhausted\n");
		mutex_unlock(&function_mutex);
		return -ENOMEM;
	}

dev_dbg(device, "Creating sysfs mapping for device %s\n",
		device->kobj.name);

mapping = &dev_mappings[map_idx];
	mapping->attributes = kcalloc(GASKET_SYSFS_MAX_NODES,
				      sizeof(*mapping->attributes),
				      GFP_KERNEL);
	if (!mapping->attributes) {
		dev_dbg(device, "Unable to allocate sysfs attribute array\n");
		mutex_unlock(&mapping->mutex);
		mutex_unlock(&function_mutex);
		return -ENOMEM;
	}

kref_init(&mapping->refcount);
	mapping->device = get_device(device);
	mapping->gasket_dev = gasket_dev;
	mapping->attribute_count = 0;
	mutex_unlock(&mapping->mutex);
	mutex_unlock(&function_mutex);

/* Don't decrement the refcount here! One open count keeps it alive! */
	return 0;
}

int gasket_sysfs_create_entries(struct device *device,
				const struct gasket_sysfs_attribute *attrs)
{
	int i;
	int ret;
	struct gasket_sysfs_mapping *mapping = get_mapping(device);

if (!mapping) {
		dev_dbg(device,
			"Creating entries for device without first "
			"initializing mapping\n");
		return -EINVAL;
	}

mutex_lock(&mapping->mutex);
	for (i = 0; strcmp(attrs[i].attr.attr.name, GASKET_ARRAY_END_MARKER);
		i++) {
		if (mapping->attribute_count == GASKET_SYSFS_MAX_NODES) {
			dev_err(device,
				"Maximum number of sysfs nodes reached for "
				"device\n");
			mutex_unlock(&mapping->mutex);
			put_mapping(mapping);
			return -ENOMEM;
		}

ret = device_create_file(device, &attrs[i].attr);
		if (ret) {
			dev_dbg(device, "Unable to create device entries\n");
			mutex_unlock(&mapping->mutex);
			put_mapping(mapping);
			return ret;
		}

mapping->attributes[mapping->attribute_count] = attrs[i];
		++mapping->attribute_count;
	}

mutex_unlock(&mapping->mutex);
	put_mapping(mapping);
	return 0;
}
EXPORT_SYMBOL(gasket_sysfs_create_entries);

void gasket_sysfs_remove_mapping(struct device *device)
{
	struct gasket_sysfs_mapping *mapping = get_mapping(device);

if (!mapping) {
		dev_err(device,
			"Attempted to remove non-existent sysfs mapping to "
			"device\n");
		return;
	}

put_mapping_n(mapping, 2);
}

struct gasket_dev *gasket_sysfs_get_device_data(struct device *device)
{
	struct gasket_sysfs_mapping *mapping = get_mapping(device);

if (!mapping) {
		dev_err(device, "device not registered\n");
		return NULL;
	}

return mapping->gasket_dev;
}
EXPORT_SYMBOL(gasket_sysfs_get_device_data);

void gasket_sysfs_put_device_data(struct device *device, struct gasket_dev *dev)
{
	struct gasket_sysfs_mapping *mapping = get_mapping(device);

if (!mapping)
		return;

/* See comment of put_mapping_n() for why the '2' is necessary. */
	put_mapping_n(mapping, 2);
}
EXPORT_SYMBOL(gasket_sysfs_put_device_data);

struct gasket_sysfs_attribute *
gasket_sysfs_get_attr(struct device *device, struct device_attribute *attr)
{
	int i;
	int num_attrs;
	struct gasket_sysfs_mapping *mapping = get_mapping(device);
	struct gasket_sysfs_attribute *attrs = NULL;

if (!mapping)
		return NULL;

attrs = mapping->attributes;
	num_attrs = mapping->attribute_count;
	for (i = 0; i < num_attrs; ++i) {
		if (!strcmp(attrs[i].attr.attr.name, attr->attr.name))
			return &attrs[i];
	}

dev_err(device, "Unable to find match for device_attribute %s\n",
		attr->attr.name);
	return NULL;
}
EXPORT_SYMBOL(gasket_sysfs_get_attr);

void gasket_sysfs_put_attr(struct device *device,
			   struct gasket_sysfs_attribute *attr)
{
	int i;
	int num_attrs;
	struct gasket_sysfs_mapping *mapping = get_mapping(device);
	struct gasket_sysfs_attribute *attrs = NULL;

if (!mapping)
		return;

attrs = mapping->attributes;
	num_attrs = mapping->attribute_count;
	for (i = 0; i < num_attrs; ++i) {
		if (&attrs[i] == attr) {
			put_mapping_n(mapping, 2);
			return;
		}
	}

dev_err(device, "Unable to put unknown attribute: %s\n",
		attr->attr.attr.name);
}
EXPORT_SYMBOL(gasket_sysfs_put_attr);

ssize_t gasket_sysfs_register_store(struct device *device,
				    struct device_attribute *attr,
				    const char *buf, size_t count)
{
	ulong parsed_value = 0;
	struct gasket_sysfs_mapping *mapping;
	struct gasket_dev *gasket_dev;
	struct gasket_sysfs_attribute *gasket_attr;

if (count < 3 || buf[0] != '0' || buf[1] != 'x') {
		dev_err(device,
			"sysfs register write format: \"0x<hex value>\"\n");
		return -EINVAL;
	}

if (kstrtoul(buf, 16, &parsed_value) != 0) {
		dev_err(device,
			"Unable to parse input as 64-bit hex value: %s\n", buf);
		return -EINVAL;
	}

mapping = get_mapping(device);
	if (!mapping) {
		dev_err(device, "Device driver may have been removed\n");
		return 0;
	}

gasket_dev = mapping->gasket_dev;
	if (!gasket_dev) {
		dev_err(device, "Device driver may have been removed\n");
		return 0;
	}

gasket_attr = gasket_sysfs_get_attr(device, attr);
	if (!gasket_attr) {
		put_mapping(mapping);
		return count;
	}

gasket_dev_write_64(gasket_dev, parsed_value,
			    gasket_attr->data.bar_address.bar,
			    gasket_attr->data.bar_address.offset);

if (gasket_attr->write_callback)
		gasket_attr->write_callback(gasket_dev, gasket_attr,
					    parsed_value);

gasket_sysfs_put_attr(device, gasket_attr);
	put_mapping(mapping);
	return count;
}
EXPORT_SYMBOL(gasket_sysfs_register_store);
0707010000001D000081A40000000000000000000000016217DF4F00001A2B000000000000000000000000000000000000002800000000gasket-driver-1.0.18/src/gasket_sysfs.h/* SPDX-License-Identifier: GPL-2.0 */
/*
 * Set of common sysfs utilities.
 *
 * Copyright (C) 2018 Google, Inc.
 */

/* The functions described here are a set of utilities to allow each file in the
 * Gasket driver framework to manage their own set of sysfs entries, instead of
 * centralizing all that work in one file.
 *
 * The goal of these utilities is to allow for sysfs entries to be easily
 * created without causing a proliferation of sysfs "show" functions. This
 * requires O(N) string lookups during show function execution, but as reading
 * sysfs entries is rarely performance-critical, this is likely acceptible.
 */
#ifndef __GASKET_SYSFS_H__
#define __GASKET_SYSFS_H__

#include "gasket_constants.h"
#include "gasket_core.h"
#include <linux/device.h>
#include <linux/stringify.h>
#include <linux/sysfs.h>

/* The maximum number of mappings/devices a driver needs to support. */
#define GASKET_SYSFS_NUM_MAPPINGS (GASKET_FRAMEWORK_DESC_MAX * GASKET_DEV_MAX)

/* The maximum number of sysfs nodes in a directory.
 */
#define GASKET_SYSFS_MAX_NODES 196

/* End markers for sysfs struct arrays. */
#define GASKET_ARRAY_END_TOKEN GASKET_RESERVED_ARRAY_END
#define GASKET_ARRAY_END_MARKER __stringify(GASKET_ARRAY_END_TOKEN)

/*
 * Terminator struct for a gasket_sysfs_attr array. Must be at the end of
 * all gasket_sysfs_attribute arrays.
 */
#define GASKET_END_OF_ATTR_ARRAY                                               \
	{                                                                      \
		.attr = __ATTR(GASKET_ARRAY_END_TOKEN, S_IRUGO, NULL, NULL),   \
		.data.attr_type = 0,                                           \
	}

/*
 * Pairing of sysfs attribute and user data.
 * Used in lookups in sysfs "show" functions to return attribute metadata.
 */
struct gasket_sysfs_attribute {
	/* The underlying sysfs device attribute associated with this data. */
	struct device_attribute attr;

/* User-specified data to associate with the attribute. */
	union {
		struct bar_address_ {
			ulong bar;
			ulong offset;
		} bar_address;
		uint attr_type;
	} data;

/*
	 * Function pointer to a callback to be invoked when this attribute is
	 * written (if so configured). The arguments are to the Gasket device
	 * pointer, the enclosing gasket_attr structure, and the value written.
	 * The callback should perform any logging necessary, as errors cannot
	 * be returned from the callback.
	 */
	void (*write_callback)(struct gasket_dev *dev,
			       struct gasket_sysfs_attribute *attr,
			       ulong value);
};

#define GASKET_SYSFS_RO(_name, _show_function, _attr_type)                     \
	{                                                                      \
		.attr = __ATTR(_name, S_IRUGO, _show_function, NULL),          \
		.data.attr_type = _attr_type                                   \
	}

#define GASKET_SYSFS_RW(_name, _show_function, _store_function, _attr_type)    \
	{                                                                      \
		.attr = __ATTR(_name, S_IWUSR | S_IWGRP | S_IRUGO,             \
				_show_function, _store_function),              \
		.data.attr_type = _attr_type                                   \
	}

/* Initializes the Gasket sysfs subsystem.
 *
 * Description: Performs one-time initialization. Must be called before usage
 * at [Gasket] module load time.
 */
void gasket_sysfs_init(void);

/*
 * Create an entry in mapping_data between a device and a Gasket device.
 * @device: Device struct to map to.
 * @gasket_dev: The dev struct associated with the driver controlling @device.
 *
 * Description: This function maps a gasket_dev* to a device*. This mapping can
 * be used in sysfs_show functions to get a handle to the gasket_dev struct
 * controlling the device node.
 *
 * If this function is not called before gasket_sysfs_create_entries, a warning
 * will be logged.
 */
int gasket_sysfs_create_mapping(struct device *device,
				struct gasket_dev *gasket_dev);

/*
 * Creates bulk entries in sysfs.
 * @device: Kernel device structure.
 * @attrs: List of attributes/sysfs entries to create.
 *
 * Description: Creates each sysfs entry described in "attrs". Can be called
 * multiple times for a given @device. If the gasket_dev specified in
 * gasket_sysfs_create_mapping had a legacy device, the entries will be created
 * for it, as well.
 */
int gasket_sysfs_create_entries(struct device *device,
				const struct gasket_sysfs_attribute *attrs);

/*
 * Removes a device mapping from the global table.
 * @device: Device to unmap.
 *
 * Description: Removes the device->Gasket device mapping from the internal
 * table.
 */
void gasket_sysfs_remove_mapping(struct device *device);

/*
 * User data lookup based on kernel device structure.
 * @device: Kernel device structure.
 *
 * Description: Returns the user data associated with "device" in a prior call
 * to gasket_sysfs_create_entries. Returns NULL if no mapping can be found.
 * Upon success, this call take a reference to internal sysfs data that must be
 * released with gasket_sysfs_put_device_data. While this reference is held, the
 * underlying device sysfs information/structure will remain valid/will not be
 * deleted.
 */
struct gasket_dev *gasket_sysfs_get_device_data(struct device *device);

/*
 * Releases a references to internal data.
 * @device: Kernel device structure.
 * @dev: Gasket device descriptor (returned by gasket_sysfs_get_device_data).
 */
void gasket_sysfs_put_device_data(struct device *device,
				  struct gasket_dev *gasket_dev);

/*
 * Gasket-specific attribute lookup.
 * @device: Kernel device structure.
 * @attr: Device attribute to look up.
 *
 * Returns the Gasket sysfs attribute associated with the kernel device
 * attribute and device structure itself. Upon success, this call will take a
 * reference to internal sysfs data that must be released with a call to
 * gasket_sysfs_put_attr. While this reference is held, the underlying device
 * sysfs information/structure will remain valid/will not be deleted.
 */
struct gasket_sysfs_attribute *
gasket_sysfs_get_attr(struct device *device, struct device_attribute *attr);

/*
 * Releases a references to internal data.
 * @device: Kernel device structure.
 * @attr: Gasket sysfs attribute descriptor (returned by
 *        gasket_sysfs_get_attr).
 */
void gasket_sysfs_put_attr(struct device *device,
			   struct gasket_sysfs_attribute *attr);

/*
 * Write to a register sysfs node.
 * @buf: NULL-terminated data being written.
 * @count: number of bytes in the "buf" argument.
 */
ssize_t gasket_sysfs_register_store(struct device *device,
				    struct device_attribute *attr,
				    const char *buf, size_t count);

#endif /* __GASKET_SYSFS_H__ */
07070100000000000000000000000000000000000000010000000000000000000000000000000000000000000000000000000B00000000TRAILER!!!502 blocks

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