diff options
| author | Gautham R. Shenoy <ego@linux.vnet.ibm.com> | 2015-08-05 12:38:31 +0530 |
|---|---|---|
| committer | Michael Ellerman <mpe@ellerman.id.au> | 2015-08-14 15:58:28 +1000 |
| commit | e63dbd16ab7be41f5b66a70f1082242d76dd21d7 (patch) | |
| tree | 55996fb7acda110d3a4dd4fedb0673ed259f1607 | |
| parent | 9afac933433ca71e0f78958a1286a8d3b9de5582 (diff) | |
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 <ego@linux.vnet.ibm.com>
Reviewed-by: Sam Bobroff <sam.bobroff@au1.ibm.com>
Tested-by: Sam Bobroff <sam.bobroff@au1.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
| -rw-r--r-- | arch/powerpc/include/asm/reg.h | 9 | ||||
| -rw-r--r-- | 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 bb2758819bc9..aa1cc5f015ee 100644 --- a/arch/powerpc/include/asm/reg.h +++ b/arch/powerpc/include/asm/reg.h @@ -1280,6 +1280,15 @@ 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 f60f80ada903..503a73f59359 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 */ |