File powerpc-utils.drmgr-use_sysfs_migration_store_t... of Package powerpc-utils.557

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File powerpc-utils.drmgr-use_sysfs_migration_store_to_initiate_migratio.patch of Package powerpc-utils.557

From 63f2c6881aa46a87487ea8572df3cf46a6604dc1 Mon Sep 17 00:00:00 2001
From: Tyrel Datwyler <tyreld@linux.vnet.ibm.com>
Date: Tue, 31 Mar 2015 18:23:59 -0400
Subject: [PATCH] drmgr: Use sysfs migration store to initiate migration when
 possible

The sysfs attribute /sys/kernel/mobility/migration has been present for
sometime, but never actually used by drmgr. It can be used to initiate a
migration operation in place of the existing faux ibm,supsend-me rtas call.
Further, newer kernels are capable of doing the device tree update.

We can test the /sys/kernel/mobility/api_version attribute to determine the
course of action drmgr should take. Newer kernels will return 1 indicating
the kernel is cabable of performing the migration and postmobility fixups.
If the attribute is unreadable or returns 0 drmgr should resort to initiating
the migration via rtas, and communicate the post mobility device tree update
through the /proc/ppc64/ofdt interface to the kernel.

Signed-off-by: Tyrel Datwyler <tyreld@linux.vnet.ibm.com>
---
 src/drmgr/drmig_chrp_pmig.c | 56 ++++++++++++++++++++++++++++++++++++++++-----
 1 file changed, 50 insertions(+), 6 deletions(-)

diff --git a/src/drmgr/drmig_chrp_pmig.c b/src/drmgr/drmig_chrp_pmig.c
index a7c1ec5..8e8f9d0 100644
--- a/src/drmgr/drmig_chrp_pmig.c
+++ b/src/drmgr/drmig_chrp_pmig.c
@@ -28,6 +28,13 @@ struct pmap_struct {
 };
 
 #define SYSFS_HIBERNATION_FILE	"/sys/devices/system/power/hibernate"
+#define SYSFS_MIGRATION_FILE	"/sys/kernel/mobility/migration"
+#define SYSFS_MIGRATION_API_FILE "/sys/kernel/mobility/api_version"
+
+/* drmgr must call ibm,suspend-me and is responsible for postmobility fixups */
+#define MIGRATION_API_V0	0
+/* drmgr must write to sysfs migration store and allow kernel to do postmobility fixups */
+#define MIGRATION_API_V1	1
 
 static struct pmap_struct *plist;
 static int action = 0;
@@ -559,11 +566,48 @@ valid_pmig_options(struct options *opts)
 
 int do_migration(uint64_t stream_val)
 {
-	int rc;
+	int rc, fd;
+	int api_level = 0;
+	char buf[64];
+
+	/* If the kernel can also do the device tree update we should let the kernel do all the work.
+	   Check if sysfs migration api_version is readable and use api level to determine how to
+	   perform migration and post-mobility updates. */
+	rc = get_int_attribute(SYSFS_MIGRATION_API_FILE, NULL, &api_level, sizeof(&api_level));
+	if (rc)
+		say(DEBUG,"get_int_attribute returned %d for path %s\n", rc, SYSFS_MIGRATION_API_FILE);
+
+	if (api_level == MIGRATION_API_V0) {
+		say(DEBUG, "about to issue ibm,suspend-me(%llx)\n", stream_val);
+		rc = rtas_suspend_me(stream_val);
+		say(DEBUG, "ibm,suspend-me() returned %d\n", rc);
+	} else if (api_level == MIGRATION_API_V1) {
+		sprintf(buf, "0x%llx\n", stream_val);
+
+		fd = open(SYSFS_MIGRATION_FILE, O_WRONLY);
+		if (fd == -1) {
+			say(ERROR, "Could not open \"%s\" to initiate migration, "
+			    "%m\n", SYSFS_MIGRATION_FILE);
+			return -1;
+		}
+
+		say(DEBUG, "Initiating migration via %s with %s\n",
+		    SYSFS_MIGRATION_FILE, buf);
+
+		rc = write(fd, buf, strlen(buf));
+		if (rc < 0) {
+			say(DEBUG, "Write to migration file failed with rc: %d\n", rc);
+			rc = errno;
+		} else if (rc > 0)
+			rc = 0;
+
+		close(fd);
+		say(DEBUG, "Kernel migration returned %d\n", rc);
+	} else {
+		say(ERROR, "Unknown kernel migration api version %d\n", api_level);
+		rc = -1;
+	}
 
-	say(DEBUG, "about to issue ibm,suspend-me(%llx)\n", stream_val);
-	rc = rtas_suspend_me(stream_val);
-	say(DEBUG, "ibm,suspend-me() returned %d\n", rc);
 	return rc;
 }
 
@@ -604,9 +648,9 @@ void post_mobility_update(int action)
 	char *path;
 
 	if (action == HIBERNATE)
-		path = "/sys/devices/system/power/hibernate";
+		path = SYSFS_HIBERNATION_FILE;
 	else
-		path = "/sys/kernel/mobility/migrate";
+		path = SYSFS_MIGRATION_API_FILE;
 
 	/* kernel will return 0 or sysfs attribute will be unreadable if drmgr
 	   needs to perform a device tree update */
-- 
1.8.5.2

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File powerpc-utils.drmgr-use_sysfs_migration_store_to_initiate_migratio.patch of Package powerpc-utils.557

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