Re: [PATCH] powerpc/pseries: Introduce api_version to migration sysfs interface

2015-03-23 Thread Tyrel Datwyler
On 03/04/2015 06:25 PM, Tyrel Datwyler wrote:
 The /sys/kernel/mobility/migration interface was added all the way back
 in 2.6.37. However, the drmgr userspace tool was never augmented to use
 this interface to perfrom migrations. Instead it has continued using a
 faux rtas call coupled with performing the device tree update processing
 in userspace and communicating it back to the kernel via the ugly
 /proc/ppc64/ofdt interface.
 
 Up until 3.12 the device tree update code in the kernel was badly broken
 and bit rotting. This code was fixed in 3.12 and is now utilized by the
 kernel suspend code as of 3.15. The kernel is now better suited to
 handle the post-mobility fixup of the device tree and drmgr should be
 transitioned to using the sysfs migration interface.
 
 This patch introduces the api_version sysfs file to /sys/kernel/mobility
 as a means for drmgr to query the current implementation level of the
 kernel migration code. This initial versioning indicates it is capable
 of perfroming all current PAPR requirements for migration including the
 post-mobility firmware activation and device tree update.
 
 Signed-off-by: Tyrel Datwyler tyr...@linux.vnet.ibm.com
 Cc: Nathan Fontenot nf...@linux.vnet.ibm.com
 Cc: Cyril Bur cyril...@gmail.com
 ---

Ping. Does this look acceptable for -next?

-Tyrel

  arch/powerpc/platforms/pseries/mobility.c | 17 -
  1 file changed, 16 insertions(+), 1 deletion(-)
 
 diff --git a/arch/powerpc/platforms/pseries/mobility.c 
 b/arch/powerpc/platforms/pseries/mobility.c
 index bdf62c1..ceb18d3 100644
 --- a/arch/powerpc/platforms/pseries/mobility.c
 +++ b/arch/powerpc/platforms/pseries/mobility.c
 @@ -338,7 +338,16 @@ static ssize_t migrate_store(struct class *class, struct 
 class_attribute *attr,
   return count;
  }
 
 +/*
 + * Used by drmgr to determine the kernel behavior of the migration interface.
 + *
 + * Version 1: Performs all PAPR requirements for migration including
 + *   firmware activation and device tree update.
 + */
 +#define MIGRATION_API_VERSION1
 +
  static CLASS_ATTR(migration, S_IWUSR, NULL, migrate_store);
 +static CLASS_ATTR_STRING(api_version, S_IRUGO, 
 __stringify(MIGRATION_API_VERSION));
 
  static int __init mobility_sysfs_init(void)
  {
 @@ -349,7 +358,13 @@ static int __init mobility_sysfs_init(void)
   return -ENOMEM;
 
   rc = sysfs_create_file(mobility_kobj, class_attr_migration.attr);
 + if (rc)
 + pr_err(mobility: unable to create migration sysfs file 
 (%d)\n, rc);
 
 - return rc;
 + rc = sysfs_create_file(mobility_kobj, 
 class_attr_api_version.attr.attr);
 + if (rc)
 + pr_err(mobility: unable to create api_version sysfs file 
 (%d)\n, rc);
 +
 + return 0;
  }
  machine_device_initcall(pseries, mobility_sysfs_init);
 

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[PATCH] powerpc/pseries: Introduce api_version to migration sysfs interface

2015-03-04 Thread Tyrel Datwyler
The /sys/kernel/mobility/migration interface was added all the way back
in 2.6.37. However, the drmgr userspace tool was never augmented to use
this interface to perfrom migrations. Instead it has continued using a
faux rtas call coupled with performing the device tree update processing
in userspace and communicating it back to the kernel via the ugly
/proc/ppc64/ofdt interface.

Up until 3.12 the device tree update code in the kernel was badly broken
and bit rotting. This code was fixed in 3.12 and is now utilized by the
kernel suspend code as of 3.15. The kernel is now better suited to
handle the post-mobility fixup of the device tree and drmgr should be
transitioned to using the sysfs migration interface.

This patch introduces the api_version sysfs file to /sys/kernel/mobility
as a means for drmgr to query the current implementation level of the
kernel migration code. This initial versioning indicates it is capable
of perfroming all current PAPR requirements for migration including the
post-mobility firmware activation and device tree update.

Signed-off-by: Tyrel Datwyler tyr...@linux.vnet.ibm.com
Cc: Nathan Fontenot nf...@linux.vnet.ibm.com
Cc: Cyril Bur cyril...@gmail.com
---
 arch/powerpc/platforms/pseries/mobility.c | 17 -
 1 file changed, 16 insertions(+), 1 deletion(-)

diff --git a/arch/powerpc/platforms/pseries/mobility.c 
b/arch/powerpc/platforms/pseries/mobility.c
index bdf62c1..ceb18d3 100644
--- a/arch/powerpc/platforms/pseries/mobility.c
+++ b/arch/powerpc/platforms/pseries/mobility.c
@@ -338,7 +338,16 @@ static ssize_t migrate_store(struct class *class, struct 
class_attribute *attr,
return count;
 }
 
+/*
+ * Used by drmgr to determine the kernel behavior of the migration interface.
+ *
+ * Version 1: Performs all PAPR requirements for migration including
+ * firmware activation and device tree update.
+ */
+#define MIGRATION_API_VERSION  1
+
 static CLASS_ATTR(migration, S_IWUSR, NULL, migrate_store);
+static CLASS_ATTR_STRING(api_version, S_IRUGO, 
__stringify(MIGRATION_API_VERSION));
 
 static int __init mobility_sysfs_init(void)
 {
@@ -349,7 +358,13 @@ static int __init mobility_sysfs_init(void)
return -ENOMEM;
 
rc = sysfs_create_file(mobility_kobj, class_attr_migration.attr);
+   if (rc)
+   pr_err(mobility: unable to create migration sysfs file 
(%d)\n, rc);
 
-   return rc;
+   rc = sysfs_create_file(mobility_kobj, 
class_attr_api_version.attr.attr);
+   if (rc)
+   pr_err(mobility: unable to create api_version sysfs file 
(%d)\n, rc);
+
+   return 0;
 }
 machine_device_initcall(pseries, mobility_sysfs_init);
-- 
1.7.12.2

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