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perf/x86/amd/ibs: Handle erratum torvalds#420 only on the affected CP…
…U family (10h) [ Upstream commit e431e79 ] This saves us writing the IBS control MSR twice when disabling the event. I searched revision guides for all families since 10h, and did not find occurrence of erratum torvalds#420, nor anything remotely similar: so we isolate the secondary MSR write to family 10h only. Also unconditionally update the count mask for IBS Op implementations that have read & writeable current count (CurCnt) fields in addition to the MaxCnt field. These bits were reserved on prior implementations, and therefore shouldn't have negative impact. Signed-off-by: Kim Phillips <kim.phillips@amd.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com> Cc: Arnaldo Carvalho de Melo <acme@kernel.org> Cc: Arnaldo Carvalho de Melo <acme@redhat.com> Cc: Borislav Petkov <bp@alien8.de> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Jiri Olsa <jolsa@redhat.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Mark Rutland <mark.rutland@arm.com> Cc: Namhyung Kim <namhyung@kernel.org> Cc: Stephane Eranian <eranian@google.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Vince Weaver <vincent.weaver@maine.edu> Fixes: c9574fe ("perf/x86-ibs: Implement workaround for IBS erratum torvalds#420") Link: https://lkml.kernel.org/r/20191023150955.30292-2-kim.phillips@amd.com Signed-off-by: Ingo Molnar <mingo@kernel.org> Signed-off-by: Sasha Levin <sashal@kernel.org>
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