diff options
| author | Nicholas Piggin <npiggin@gmail.com> | 2017-04-19 23:05:45 +1000 |
|---|---|---|
| committer | Michael Ellerman <mpe@ellerman.id.au> | 2017-04-23 20:31:39 +1000 |
| commit | 544686cae8e4f5bbcd153998dcaf4a3d5b94e6be (patch) | |
| tree | 51eaa1f72ea0c6967e930ffcd3fe1d2562940bbe /arch/powerpc/include/asm/exception-64s.h | |
| parent | bf0153c143a694e7bb3b28d92eafd8b3ef6db870 (diff) | |
powerpc/64s: Stop using bit in HSPRG0 to test winkle
The POWER8 idle code has a neat trick of programming the power on engine
to restore a low bit into HSPRG0, so idle wakeup code can test and see
if it has been programmed this way and therefore lost all state. Restore
time can be reduced if winkle has not been reached.
However this messes with our r13 PACA pointer, and requires HSPRG0 to be
written to. It also optimizes the slowest and most uncommon case at the
expense of another SPR write in the common nap state wakeup.
Remove this complexity and assume winkle sleeps always require a state
restore. This speedup could be made entirely contained within the winkle
idle code by counting per-core winkles and setting a thread bitmap when
all have gone to winkle.
Reviewed-by: Gautham R. Shenoy <ego@linux.vnet.ibm.com>
Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Diffstat (limited to 'arch/powerpc/include/asm/exception-64s.h')
| -rw-r--r-- | arch/powerpc/include/asm/exception-64s.h | 13 |
1 files changed, 2 insertions, 11 deletions
diff --git a/arch/powerpc/include/asm/exception-64s.h b/arch/powerpc/include/asm/exception-64s.h index 437550175b4d..89259817f5ef 100644 --- a/arch/powerpc/include/asm/exception-64s.h +++ b/arch/powerpc/include/asm/exception-64s.h @@ -167,17 +167,14 @@ BEGIN_FTR_SECTION_NESTED(943) \ std ra,offset(r13); \ END_FTR_SECTION_NESTED(ftr,ftr,943) -#define EXCEPTION_PROLOG_0_PACA(area) \ +#define EXCEPTION_PROLOG_0(area) \ + GET_PACA(r13); \ std r9,area+EX_R9(r13); /* save r9 */ \ OPT_GET_SPR(r9, SPRN_PPR, CPU_FTR_HAS_PPR); \ HMT_MEDIUM; \ std r10,area+EX_R10(r13); /* save r10 - r12 */ \ OPT_GET_SPR(r10, SPRN_CFAR, CPU_FTR_CFAR) -#define EXCEPTION_PROLOG_0(area) \ - GET_PACA(r13); \ - EXCEPTION_PROLOG_0_PACA(area) - #define __EXCEPTION_PROLOG_1(area, extra, vec) \ OPT_SAVE_REG_TO_PACA(area+EX_PPR, r9, CPU_FTR_HAS_PPR); \ OPT_SAVE_REG_TO_PACA(area+EX_CFAR, r10, CPU_FTR_CFAR); \ @@ -208,12 +205,6 @@ END_FTR_SECTION_NESTED(ftr,ftr,943) EXCEPTION_PROLOG_1(area, extra, vec); \ EXCEPTION_PROLOG_PSERIES_1(label, h); -/* Have the PACA in r13 already */ -#define EXCEPTION_PROLOG_PSERIES_PACA(area, label, h, extra, vec) \ - EXCEPTION_PROLOG_0_PACA(area); \ - EXCEPTION_PROLOG_1(area, extra, vec); \ - EXCEPTION_PROLOG_PSERIES_1(label, h); - #define __KVMTEST(h, n) \ lbz r10,HSTATE_IN_GUEST(r13); \ cmpwi r10,0; \ |