Re: [PATCH v3] powerpc: Add an inline function to update POWER8 HID0
On 08/05/2015 12:38 PM, Gautham R. Shenoy wrote: > Section 3.7 of Version 1.2 of the Power8 Processor User's Manual > prescribes that updates to HID0 be preceded by a SYNC instruction and > followed by an ISYNC instruction (Page 91). > > Create an inline function name update_power8_hid0() which follows this > recipe and invoke it from the static split core path. > > Signed-off-by: Gautham R. Shenoy Reviewed-by: Shreyas B. Prabhu -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
Re: [PATCH v3] powerpc: Add an inline function to update POWER8 HID0
On 08/05/2015 12:38 PM, Gautham R. Shenoy wrote: Section 3.7 of Version 1.2 of the Power8 Processor User's Manual prescribes that updates to HID0 be preceded by a SYNC instruction and followed by an ISYNC instruction (Page 91). Create an inline function name update_power8_hid0() which follows this recipe and invoke it from the static split core path. Signed-off-by: Gautham R. Shenoy e...@linux.vnet.ibm.com Reviewed-by: Shreyas B. Prabhu shre...@linux.vnet.ibm.com -- To unsubscribe from this list: send the line unsubscribe linux-kernel in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
Re: [PATCH v3] powerpc: Add an inline function to update POWER8 HID0
On Wed, Aug 05, 2015 at 12:38:31PM +0530, Gautham R. Shenoy wrote: > Section 3.7 of Version 1.2 of the Power8 Processor User's Manual > prescribes that updates to HID0 be preceded by a SYNC instruction and > followed by an ISYNC instruction (Page 91). > > Create an inline function name update_power8_hid0() which follows this > recipe and invoke it from the static split core path. > > Signed-off-by: Gautham R. Shenoy Hi Gautham, I've tested this on a Power 8 machine and verified that it is able to change split modes and that when doing so the new code is used. Reviewed-by: Sam Bobroff Tested-by: Sam Bobroff -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
Re: [PATCH v3] powerpc: Add an inline function to update POWER8 HID0
On Wed, Aug 05, 2015 at 12:38:31PM +0530, Gautham R. Shenoy wrote: Section 3.7 of Version 1.2 of the Power8 Processor User's Manual prescribes that updates to HID0 be preceded by a SYNC instruction and followed by an ISYNC instruction (Page 91). Create an inline function name update_power8_hid0() which follows this recipe and invoke it from the static split core path. Signed-off-by: Gautham R. Shenoy e...@linux.vnet.ibm.com Hi Gautham, I've tested this on a Power 8 machine and verified that it is able to change split modes and that when doing so the new code is used. Reviewed-by: Sam Bobroff sam.bobr...@au1.ibm.com Tested-by: Sam Bobroff sam.bobr...@au1.ibm.com -- To unsubscribe from this list: send the line unsubscribe linux-kernel in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
[PATCH v3] powerpc: Add an inline function to update POWER8 HID0
Section 3.7 of Version 1.2 of the Power8 Processor User's Manual prescribes that updates to HID0 be preceded by a SYNC instruction and followed by an ISYNC instruction (Page 91). Create an inline function name update_power8_hid0() which follows this recipe and invoke it from the static split core path. Signed-off-by: Gautham R. Shenoy --- [v1 --> v2: Moved defn of update_hid0 to reg.h from kvm_ppc.h] [v2 --> v3: Renamed to update_power8_hid0 and used asm volatile] arch/powerpc/include/asm/reg.h | 9 + arch/powerpc/platforms/powernv/subcore.c | 4 ++-- 2 files changed, 11 insertions(+), 2 deletions(-) diff --git a/arch/powerpc/include/asm/reg.h b/arch/powerpc/include/asm/reg.h index af56b5c..1245d99 100644 --- a/arch/powerpc/include/asm/reg.h +++ b/arch/powerpc/include/asm/reg.h @@ -1281,6 +1281,15 @@ struct pt_regs; extern void ppc_save_regs(struct pt_regs *regs); +static inline void update_power8_hid0(unsigned long hid0) +{ + /* +* The HID0 update on Power8 should at the very least be +* preceded by a a SYNC instruction followed by an ISYNC +* instruction +*/ + asm volatile("sync; mtspr %0,%1; isync":: "i"(SPRN_HID0), "r"(hid0)); +} #endif /* __ASSEMBLY__ */ #endif /* __KERNEL__ */ #endif /* _ASM_POWERPC_REG_H */ diff --git a/arch/powerpc/platforms/powernv/subcore.c b/arch/powerpc/platforms/powernv/subcore.c index f60f80a..503a73f 100644 --- a/arch/powerpc/platforms/powernv/subcore.c +++ b/arch/powerpc/platforms/powernv/subcore.c @@ -190,7 +190,7 @@ static void unsplit_core(void) hid0 = mfspr(SPRN_HID0); hid0 &= ~HID0_POWER8_DYNLPARDIS; - mtspr(SPRN_HID0, hid0); + update_power8_hid0(hid0); update_hid_in_slw(hid0); while (mfspr(SPRN_HID0) & mask) @@ -227,7 +227,7 @@ static void split_core(int new_mode) /* Write new mode */ hid0 = mfspr(SPRN_HID0); hid0 |= HID0_POWER8_DYNLPARDIS | split_parms[i].value; - mtspr(SPRN_HID0, hid0); + update_power8_hid0(hid0); update_hid_in_slw(hid0); /* Wait for it to happen */ -- 1.9.3 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
[PATCH v3] powerpc: Add an inline function to update POWER8 HID0
Section 3.7 of Version 1.2 of the Power8 Processor User's Manual prescribes that updates to HID0 be preceded by a SYNC instruction and followed by an ISYNC instruction (Page 91). Create an inline function name update_power8_hid0() which follows this recipe and invoke it from the static split core path. Signed-off-by: Gautham R. Shenoy e...@linux.vnet.ibm.com --- [v1 -- v2: Moved defn of update_hid0 to reg.h from kvm_ppc.h] [v2 -- v3: Renamed to update_power8_hid0 and used asm volatile] arch/powerpc/include/asm/reg.h | 9 + arch/powerpc/platforms/powernv/subcore.c | 4 ++-- 2 files changed, 11 insertions(+), 2 deletions(-) diff --git a/arch/powerpc/include/asm/reg.h b/arch/powerpc/include/asm/reg.h index af56b5c..1245d99 100644 --- a/arch/powerpc/include/asm/reg.h +++ b/arch/powerpc/include/asm/reg.h @@ -1281,6 +1281,15 @@ struct pt_regs; extern void ppc_save_regs(struct pt_regs *regs); +static inline void update_power8_hid0(unsigned long hid0) +{ + /* +* The HID0 update on Power8 should at the very least be +* preceded by a a SYNC instruction followed by an ISYNC +* instruction +*/ + asm volatile(sync; mtspr %0,%1; isync:: i(SPRN_HID0), r(hid0)); +} #endif /* __ASSEMBLY__ */ #endif /* __KERNEL__ */ #endif /* _ASM_POWERPC_REG_H */ diff --git a/arch/powerpc/platforms/powernv/subcore.c b/arch/powerpc/platforms/powernv/subcore.c index f60f80a..503a73f 100644 --- a/arch/powerpc/platforms/powernv/subcore.c +++ b/arch/powerpc/platforms/powernv/subcore.c @@ -190,7 +190,7 @@ static void unsplit_core(void) hid0 = mfspr(SPRN_HID0); hid0 = ~HID0_POWER8_DYNLPARDIS; - mtspr(SPRN_HID0, hid0); + update_power8_hid0(hid0); update_hid_in_slw(hid0); while (mfspr(SPRN_HID0) mask) @@ -227,7 +227,7 @@ static void split_core(int new_mode) /* Write new mode */ hid0 = mfspr(SPRN_HID0); hid0 |= HID0_POWER8_DYNLPARDIS | split_parms[i].value; - mtspr(SPRN_HID0, hid0); + update_power8_hid0(hid0); update_hid_in_slw(hid0); /* Wait for it to happen */ -- 1.9.3 -- To unsubscribe from this list: send the line unsubscribe linux-kernel in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/