Add DSCR SPR to sysfs

Add DSCR SPR to sysfs

[Anton Blanchard]

POWER6 adds a new SPR, the data stream control register (DSCR). It can
be used to adjust how agressive the prefetch mechanisms are.

Its possible we may want to context switch this, but for now just export
it to userspace via sysfs so we can adjust it.

Signed-off-by: Anton Blanchard <anton@samba.org>
---

diff --git a/arch/powerpc/kernel/sysfs.c b/arch/powerpc/kernel/sysfs.c
index d45a168..505e0f4 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(dscr, SPRN_DSCR);
 
 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(dscr, 0600, show_dscr, store_dscr);
 
 static void register_cpu_online(unsigned int cpu)
 {
@@ -232,6 +234,9 @@ static void register_cpu_online(unsigned int cpu)
 
 	if (cpu_has_feature(CPU_FTR_PURR))
 		sysdev_create_file(s, &attr_purr);
+
+	if (cpu_has_feature(CPU_FTR_DSCR))
+		sysdev_create_file(s, &attr_dscr);
 }
 
 #ifdef CONFIG_HOTPLUG_CPU
@@ -274,6 +279,9 @@ static void unregister_cpu_online(unsigned int cpu)
 
 	if (cpu_has_feature(CPU_FTR_PURR))
 		sysdev_remove_file(s, &attr_purr);
+
+	if (cpu_has_feature(CPU_FTR_DSCR))
+		sysdev_remove_file(s, &attr_dscr);
 }
 #endif /* CONFIG_HOTPLUG_CPU */
 
diff --git a/include/asm-powerpc/cputable.h b/include/asm-powerpc/cputable.h
index a9a4014..9548fee 100644
--- a/include/asm-powerpc/cputable.h
+++ b/include/asm-powerpc/cputable.h
@@ -148,6 +148,7 @@ 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_DSCR			LONG_ASM_CONST(0x0001000000000000)
 
 #ifndef __ASSEMBLY__
 
@@ -332,7 +333,8 @@ extern void do_feature_fixups(unsigned long value, void *fixup_start,
 	    CPU_FTR_HPTE_TABLE | CPU_FTR_PPCAS_ARCH_V2 | CPU_FTR_CTRL | \
 	    CPU_FTR_MMCRA | CPU_FTR_SMT | \
 	    CPU_FTR_COHERENT_ICACHE | CPU_FTR_LOCKLESS_TLBIE | \
-	    CPU_FTR_PURR | CPU_FTR_CI_LARGE_PAGE | CPU_FTR_REAL_LE)
+	    CPU_FTR_PURR | CPU_FTR_CI_LARGE_PAGE | CPU_FTR_REAL_LE | \
+	    CPU_FTR_DSCR)
 #define CPU_FTRS_CELL	(CPU_FTR_SPLIT_ID_CACHE | CPU_FTR_USE_TB | \
 	    CPU_FTR_HPTE_TABLE | CPU_FTR_PPCAS_ARCH_V2 | CPU_FTR_CTRL | \
 	    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 6faae7b..cacdecc 100644
--- a/include/asm-powerpc/reg.h
+++ b/include/asm-powerpc/reg.h
@@ -143,6 +143,7 @@
 
 /* Special Purpose Registers (SPRNs)*/
 #define SPRN_CTR	0x009	/* Count Register */
+#define SPRN_DSCR	0x11
 #define SPRN_CTRLF	0x088
 #define SPRN_CTRLT	0x098
 #define   CTRL_CT	0xc0000000	/* current thread */

Re: Add DSCR SPR to sysfs

[Paul Mackerras]

Anton Blanchard writes:

> POWER6 adds a new SPR, the data stream control register (DSCR). It can
> be used to adjust how agressive the prefetch mechanisms are.
> 
> Its possible we may want to context switch this, but for now just export
> it to userspace via sysfs so we can adjust it.

I think you need to adjust both CPU_FTRS_POWER6 and CPU_FTRS_POWER6X
in include/asm-powerpc/cputable.h, don't you?  Your patch doesn't
apply cleanly on Linus' current tree.  Please send a rebased patch.

Thanks,
Paul.

Re: Add DSCR SPR to sysfs

[Anton Blanchard]

 
> I think you need to adjust both CPU_FTRS_POWER6 and CPU_FTRS_POWER6X
> in include/asm-powerpc/cputable.h, don't you?

Oops, totally forgot about that madness :) New patch on the way.

Anton

Re: Add DSCR SPR to sysfs

[Anton Blanchard]

POWER6 adds a new SPR, the data stream control register (DSCR). It can
be used to adjust how agressive the prefetch mechanisms are.

Its possible we may want to context switch this, but for now just export
it to userspace via sysfs so we can adjust it.

Signed-off-by: Anton Blanchard <anton@samba.org>
---

diff --git a/arch/powerpc/kernel/sysfs.c b/arch/powerpc/kernel/sysfs.c
index 63ed265..22daba5 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(dscr, SPRN_DSCR);
 
 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(dscr, 0600, show_dscr, store_dscr);
 
 static void register_cpu_online(unsigned int cpu)
 {
@@ -231,6 +233,9 @@ static void register_cpu_online(unsigned int cpu)
 
 	if (cpu_has_feature(CPU_FTR_PURR))
 		sysdev_create_file(s, &attr_purr);
+
+	if (cpu_has_feature(CPU_FTR_DSCR))
+		sysdev_create_file(s, &attr_dscr);
 }
 
 #ifdef CONFIG_HOTPLUG_CPU
@@ -272,6 +277,9 @@ static void unregister_cpu_online(unsigned int cpu)
 
 	if (cpu_has_feature(CPU_FTR_PURR))
 		sysdev_remove_file(s, &attr_purr);
+
+	if (cpu_has_feature(CPU_FTR_DSCR))
+		sysdev_remove_file(s, &attr_dscr);
 }
 #endif /* CONFIG_HOTPLUG_CPU */
 
diff --git a/include/asm-powerpc/cputable.h b/include/asm-powerpc/cputable.h
index 6fe5c9d..782adbf 100644
--- a/include/asm-powerpc/cputable.h
+++ b/include/asm-powerpc/cputable.h
@@ -152,6 +152,7 @@ extern void do_feature_fixups(unsigned long value, void *fixup_start,
 #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)
+#define CPU_FTR_DSCR			LONG_ASM_CONST(0x0002000000000000)
 
 #ifndef __ASSEMBLY__
 
@@ -330,13 +331,14 @@ extern void do_feature_fixups(unsigned long value, void *fixup_start,
 	    CPU_FTR_HPTE_TABLE | CPU_FTR_PPCAS_ARCH_V2 | CPU_FTR_CTRL | \
 	    CPU_FTR_MMCRA | CPU_FTR_SMT | \
 	    CPU_FTR_COHERENT_ICACHE | CPU_FTR_LOCKLESS_TLBIE | \
-	    CPU_FTR_PURR | CPU_FTR_SPURR | CPU_FTR_REAL_LE)
+	    CPU_FTR_PURR | CPU_FTR_SPURR | CPU_FTR_REAL_LE | \
+	    CPU_FTR_DSCR)
 #define CPU_FTRS_POWER6X (CPU_FTR_SPLIT_ID_CACHE | CPU_FTR_USE_TB | \
 	    CPU_FTR_HPTE_TABLE | CPU_FTR_PPCAS_ARCH_V2 | CPU_FTR_CTRL | \
 	    CPU_FTR_MMCRA | CPU_FTR_SMT | \
 	    CPU_FTR_COHERENT_ICACHE | CPU_FTR_LOCKLESS_TLBIE | \
 	    CPU_FTR_PURR | CPU_FTR_CI_LARGE_PAGE | \
-	    CPU_FTR_SPURR | CPU_FTR_REAL_LE)
+	    CPU_FTR_SPURR | CPU_FTR_REAL_LE | CPU_FTR_DSCR)
 #define CPU_FTRS_CELL	(CPU_FTR_SPLIT_ID_CACHE | CPU_FTR_USE_TB | \
 	    CPU_FTR_HPTE_TABLE | CPU_FTR_PPCAS_ARCH_V2 | CPU_FTR_CTRL | \
 	    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 6faae7b..cacdecc 100644
--- a/include/asm-powerpc/reg.h
+++ b/include/asm-powerpc/reg.h
@@ -143,6 +143,7 @@
 
 /* Special Purpose Registers (SPRNs)*/
 #define SPRN_CTR	0x009	/* Count Register */
+#define SPRN_DSCR	0x11
 #define SPRN_CTRLF	0x088
 #define SPRN_CTRLT	0x098
 #define   CTRL_CT	0xc0000000	/* current thread */

Add SPURR SPR to sysfs

[Anton Blanchard]

Now we have a SPURR cpu feature bit, we can export it to userspace in
sysfs.

Signed-off-by: Anton Blanchard <anton@samba.org>
---

Index: linux-2.6/arch/powerpc/kernel/sysfs.c
===================================================================
--- linux-2.6.orig/arch/powerpc/kernel/sysfs.c	2006-12-08 00:07:35.000000000 -0600
+++ linux-2.6/arch/powerpc/kernel/sysfs.c	2006-12-08 00:08:50.000000000 -0600
@@ -181,6 +181,7 @@
 SYSFS_PMCSETUP(pmc7, SPRN_PMC7);
 SYSFS_PMCSETUP(pmc8, SPRN_PMC8);
 SYSFS_PMCSETUP(purr, SPRN_PURR);
+SYSFS_PMCSETUP(spurr, SPRN_SPURR);
 SYSFS_PMCSETUP(dscr, SPRN_DSCR);
 
 static SYSDEV_ATTR(mmcr0, 0600, show_mmcr0, store_mmcr0);
@@ -195,6 +196,7 @@
 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 SYSDEV_ATTR(dscr, 0600, show_dscr, store_dscr);
 
 static void register_cpu_online(unsigned int cpu)
@@ -234,6 +236,9 @@
 	if (cpu_has_feature(CPU_FTR_PURR))
 		sysdev_create_file(s, &attr_purr);
 
+	if (cpu_has_feature(CPU_FTR_SPURR))
+		sysdev_create_file(s, &attr_spurr);
+
 	if (cpu_has_feature(CPU_FTR_DSCR))
 		sysdev_create_file(s, &attr_dscr);
 }
@@ -278,6 +283,9 @@
 	if (cpu_has_feature(CPU_FTR_PURR))
 		sysdev_remove_file(s, &attr_purr);
 
+	if (cpu_has_feature(CPU_FTR_SPURR))
+		sysdev_remove_file(s, &attr_spurr);
+
 	if (cpu_has_feature(CPU_FTR_DSCR))
 		sysdev_remove_file(s, &attr_dscr);
 }
Index: linux-2.6/include/asm-powerpc/reg.h
===================================================================
--- linux-2.6.orig/include/asm-powerpc/reg.h	2006-12-08 00:34:29.000000000 -0600
+++ linux-2.6/include/asm-powerpc/reg.h	2006-12-08 00:35:35.000000000 -0600
@@ -164,6 +164,7 @@
 #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 */