[PATCH] powerpc: Export PIR data through sysfs

[Ananth N Mavinakayanahalli]

The Processor Identification Register (PIR) on powerpc provides
information to decode the processor identification tag. Decoding
this information platform specfic.

Export PIR data via sysfs.

(Powerpc manuals state this register is 'optional'. I am not sure
though if there are any Linux supported powerpc platforms that
don't have it. Code in the kernel referencing PIR isn't under
a platform ifdef).

Signed-off-by: Ananth N Mavinakayanahalli <ananth at in.ibm.com>
---
 arch/powerpc/kernel/sysfs.c |    6 ++++++
 1 file changed, 6 insertions(+)

Index: linux-3.1/arch/powerpc/kernel/sysfs.c
===================================================================
--- linux-3.1.orig/arch/powerpc/kernel/sysfs.c
+++ linux-3.1/arch/powerpc/kernel/sysfs.c
@@ -177,11 +177,13 @@ SYSFS_PMCSETUP(mmcra, SPRN_MMCRA);
 SYSFS_PMCSETUP(purr, SPRN_PURR);
 SYSFS_PMCSETUP(spurr, SPRN_SPURR);
 SYSFS_PMCSETUP(dscr, SPRN_DSCR);
+SYSFS_PMCSETUP(pir, SPRN_PIR);
 
 static SYSDEV_ATTR(mmcra, 0600, show_mmcra, store_mmcra);
 static SYSDEV_ATTR(spurr, 0600, show_spurr, NULL);
 static SYSDEV_ATTR(dscr, 0600, show_dscr, store_dscr);
 static SYSDEV_ATTR(purr, 0600, show_purr, store_purr);
+static SYSDEV_ATTR(pir, 0400, show_pir, NULL);
 
 unsigned long dscr_default = 0;
 EXPORT_SYMBOL(dscr_default);
@@ -394,6 +396,8 @@ static void __cpuinit register_cpu_onlin
 		sysdev_create_file(s, &attr_dscr);
 #endif /* CONFIG_PPC64 */
 
+	sysdev_create_file(s, &attr_pir);
+
 	cacheinfo_cpu_online(cpu);
 }
 
@@ -464,6 +468,8 @@ static void unregister_cpu_online(unsign
 		sysdev_remove_file(s, &attr_dscr);
 #endif /* CONFIG_PPC64 */
 
+	sysdev_remove_file(s, &attr_pir);
+
 	cacheinfo_cpu_offline(cpu);
 }