From: Madhavan Srinivasan maddy@linux.vnet.ibm.com
commit 370f06c88528b3988fe24a372c10e1303bb94cf6 upstream.
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 maddy@linux.vnet.ibm.com Signed-off-by: Michael Ellerman mpe@ellerman.id.au Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org
--- arch/powerpc/perf/power8-pmu.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)
--- 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,