From: Scott Moser <smoser@redhat.com>
Date: Tue, 11 Dec 2007 16:35:25 -0500
Subject: [ppc64] power6 SPURR support
Message-id: Pine.LNX.4.64.0712111634120.19799@squad5-lp1.lab.boston.redhat.com
O-Subject: [PATCH RHEL5u2] bz253114 POWER6 SPURR support
Bugzilla: 253114

Bug 253114 [1]
---------------

Description:
-----------
POWER6 manages power and thermal issues by varying the processor clock
frequency and/or throttling instruction dispatch. In order to measure the
consumption of effective CPU resources more accurately under these
conditions, POWER6 added a Scaled Processor Utilization of Resources
Register (SPURR). This feature adds code to read the SPURR at appropriate
times in order to be able to report scaled CPU time usage to programs that
need it.

This adds just the basic SPURR read support via /sysfs.  It is non-invasive,
unlike the previous patch.  This basic support has been requested by the
EnergyScale(EMPATH) team and numerous customers.

Kernel Version:
--------------
Patch built against 2.6.18-58

Upstream Status:
---------------
This is a simple basic-function-only backport of SPURR support
that already exists upstream in git commit
f050982a9b7c4edc414f0d5543c3cb24504223c6.

Test Status:
----
To ensure cross platform build, a brew scratch build has been done against
2.6.18-58 at [2].

Mike Wolf of IBM has tested the above kernel on a POWER6 system and verified
sane functionality.  Please see the bug for more information.

Please review patch below for RHEL5u2
--
[1]:https://bugzilla.redhat.com/show_bug.cgi?id=253114
[2]:http://brewweb.devel.redhat.com/brew/taskinfo?taskID=1070129
--
 arch/powerpc/kernel/prom.c     |    1 +
 arch/powerpc/kernel/sysfs.c    |    6 ++++++
 include/asm-powerpc/cputable.h |    3 ++-
 include/asm-powerpc/reg.h      |    1 +
 4 files changed, 10 insertions(+), 1 deletion(-)

Acked-by: David Howells <dhowells@redhat.com>

diff --git a/arch/powerpc/kernel/prom.c b/arch/powerpc/kernel/prom.c
index 4bb5798..2e01f2f 100644
--- a/arch/powerpc/kernel/prom.c
+++ b/arch/powerpc/kernel/prom.c
@@ -599,6 +599,7 @@ static struct feature_property {
 #ifdef CONFIG_PPC64
 	{"ibm,dfp", 1, 0, PPC_FEATURE_HAS_DFP},
 	{"ibm,purr", 1, CPU_FTR_PURR, 0},
+	{"ibm,spurr", 1, CPU_FTR_SPURR, 0},
 #endif /* CONFIG_PPC64 */
 };
 
diff --git a/arch/powerpc/kernel/sysfs.c b/arch/powerpc/kernel/sysfs.c
index b1ca7e2..0edb176 100644
--- a/arch/powerpc/kernel/sysfs.c
+++ b/arch/powerpc/kernel/sysfs.c
@@ -181,6 +181,7 @@ SYSFS_PMCSETUP(pmc6, SPRN_PMC6);
 SYSFS_PMCSETUP(pmc7, SPRN_PMC7);
 SYSFS_PMCSETUP(pmc8, SPRN_PMC8);
 SYSFS_PMCSETUP(purr, SPRN_PURR);
+SYSFS_PMCSETUP(spurr, SPRN_SPURR);
 
 static SYSDEV_ATTR(mmcr0, 0600, show_mmcr0, store_mmcr0);
 static SYSDEV_ATTR(mmcr1, 0600, show_mmcr1, store_mmcr1);
@@ -194,6 +195,7 @@ static SYSDEV_ATTR(pmc6, 0600, show_pmc6, store_pmc6);
 static SYSDEV_ATTR(pmc7, 0600, show_pmc7, store_pmc7);
 static SYSDEV_ATTR(pmc8, 0600, show_pmc8, store_pmc8);
 static SYSDEV_ATTR(purr, 0600, show_purr, NULL);
+static SYSDEV_ATTR(spurr, 0600, show_spurr, NULL);
 
 static void register_cpu_online(unsigned int cpu)
 {
@@ -232,6 +234,8 @@ static void register_cpu_online(unsigned int cpu)
 
 	if (cpu_has_feature(CPU_FTR_SMT))
 		sysdev_create_file(s, &attr_purr);
+	if (cpu_has_feature(CPU_FTR_SPURR))
+		sysdev_create_file(s, &attr_spurr);
 }
 
 #ifdef CONFIG_HOTPLUG_CPU
@@ -274,6 +278,8 @@ static void unregister_cpu_online(unsigned int cpu)
 
 	if (cpu_has_feature(CPU_FTR_SMT))
 		sysdev_remove_file(s, &attr_purr);
+	if (cpu_has_feature(CPU_FTR_SPURR))
+		sysdev_remove_file(s, &attr_spurr);
 }
 #endif /* CONFIG_HOTPLUG_CPU */
 
diff --git a/include/asm-powerpc/cputable.h b/include/asm-powerpc/cputable.h
index c00e20d..c3c68c1 100644
--- a/include/asm-powerpc/cputable.h
+++ b/include/asm-powerpc/cputable.h
@@ -146,6 +146,7 @@ extern void do_feature_fixups(unsigned long value, void *fixup_start,
 #define CPU_FTR_PAUSE_ZERO		LONG_ASM_CONST(0x0000200000000000)
 #define CPU_FTR_PURR			LONG_ASM_CONST(0x0000400000000000)
 #define CPU_FTR_CELL_TB_BUG		LONG_ASM_CONST(0x0000800000000000)
+#define CPU_FTR_SPURR			LONG_ASM_CONST(0x0001000000000000)
 
 #ifndef __ASSEMBLY__
 
@@ -329,7 +330,7 @@ extern void do_feature_fixups(unsigned long value, void *fixup_start,
 	    CPU_FTR_HPTE_TABLE | CPU_FTR_PPCAS_ARCH_V2 | \
 	    CPU_FTR_MMCRA | CPU_FTR_SMT | \
 	    CPU_FTR_COHERENT_ICACHE | CPU_FTR_LOCKLESS_TLBIE | \
-	    CPU_FTR_PURR | CPU_FTR_REAL_LE)
+	    CPU_FTR_PURR | CPU_FTR_REAL_LE | CPU_FTR_SPURR)
 #define CPU_FTRS_CELL	(CPU_FTR_SPLIT_ID_CACHE | CPU_FTR_USE_TB | \
 	    CPU_FTR_HPTE_TABLE | CPU_FTR_PPCAS_ARCH_V2 | \
 	    CPU_FTR_ALTIVEC_COMP | CPU_FTR_MMCRA | CPU_FTR_SMT | \
diff --git a/include/asm-powerpc/reg.h b/include/asm-powerpc/reg.h
index 7e9f364..a22bcca 100644
--- a/include/asm-powerpc/reg.h
+++ b/include/asm-powerpc/reg.h
@@ -163,6 +163,7 @@
 #define SPRN_TBRU	0x10D	/* Time Base Read Upper Register (user, R/O) */
 #define SPRN_TBWL	0x11C	/* Time Base Lower Register (super, R/W) */
 #define SPRN_TBWU	0x11D	/* Time Base Upper Register (super, R/W) */
+#define SPRN_SPURR	0x134	/* Scaled PURR */
 #define SPRN_HIOR	0x137	/* 970 Hypervisor interrupt offset */
 #define SPRN_DBAT0L	0x219	/* Data BAT 0 Lower Register */
 #define SPRN_DBAT0U	0x218	/* Data BAT 0 Upper Register */