From: Madhavan Srinivasan Date: Mon, 25 Jan 2016 08:33:46 +0000 (+0530) Subject: powerpc/perf: Remove PPMU_HAS_SSLOT flag for Power8 X-Git-Url: http://drtracing.org/?a=commitdiff_plain;h=370f06c88528b3988fe24a372c10e1303bb94cf6;p=deliverable%2Flinux.git powerpc/perf: Remove PPMU_HAS_SSLOT flag for Power8 Commit 7a7868326d77 ("powerpc/perf: Add an explict flag indicating presence of SLOT field") introduced the PPMU_HAS_SSLOT flag to remove the assumption that MMCRA[SLOT] was present when PPMU_ALT_SIPR was not set. That commit's changelog also mentions that Power8 does not support MMCRA[SLOT]. However when the Power8 PMU support was merged, it errnoeously included the PPMU_HAS_SSLOT flag. So remove PPMU_HAS_SSLOT from the Power8 flags. mpe: On systems where MMCRA[SLOT] exists, the field occupies bits 37:39 (IBM numbering). On Power8 bit 37 is reserved, and 38:39 overlap with the high bits of the Threshold Event Counter Mantissa. I am not aware of any published events which use the threshold counting mechanism, which would cause the mantissa bits to be set. So in practice this bug is unlikely to trigger. Fixes: e05b9b9e5c10 ("powerpc/perf: Power8 PMU support") Signed-off-by: Madhavan Srinivasan Signed-off-by: Michael Ellerman --- diff --git a/arch/powerpc/perf/power8-pmu.c b/arch/powerpc/perf/power8-pmu.c index 7d5e295255b7..9958ba8bf0d2 100644 --- a/arch/powerpc/perf/power8-pmu.c +++ b/arch/powerpc/perf/power8-pmu.c @@ -816,7 +816,7 @@ static struct power_pmu power8_pmu = { .get_constraint = power8_get_constraint, .get_alternatives = power8_get_alternatives, .disable_pmc = power8_disable_pmc, - .flags = PPMU_HAS_SSLOT | PPMU_HAS_SIER | PPMU_ARCH_207S, + .flags = PPMU_HAS_SIER | PPMU_ARCH_207S, .n_generic = ARRAY_SIZE(power8_generic_events), .generic_events = power8_generic_events, .cache_events = &power8_cache_events,