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x86/events/intel: Do not deploy TSX force abort workaround when TSX is deprecated

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Earlier workaround added by

  400816f60c ("perf/x86/intel: Implement support for TSX Force Abort")

for perf counter interactions [1] are not required on some client
systems which received a microcode update that deprecates TSX.

Bypass the perf workaround when such microcode is enumerated.

[1] [ bp: Look for document ID 604224, "Performance Monitoring Impact
      of Intel Transactional Synchronization Extension Memory". Since
      there's no way for us to have stable links to documents... ]

 [ bp: Massage comment. ]

Signed-off-by: Pawan Gupta <pawan.kumar.gupta@linux.intel.com>
Signed-off-by: Borislav Petkov <bp@suse.de>
Reviewed-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Andi Kleen <ak@linux.intel.com>
Reviewed-by: Tony Luck <tony.luck@intel.com>
Tested-by: Neelima Krishnan <neelima.krishnan@intel.com>
Link: https://lkml.kernel.org/r/e4d410f786946280ced02dd07c74e0a74f1d10cb.1623704845.git-series.pawan.kumar.gupta@linux.intel.com
This commit is contained in:
Pawan Gupta 2021-06-14 14:13:23 -07:00 committed by Borislav Petkov
parent 1348924ba8
commit ad3c2e1749
1 changed files with 7 additions and 1 deletions
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8
arch/x86/events/intel/core.c
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@ -6015,7 +6015,13 @@ __init int intel_pmu_init(void)
tsx_attr = hsw_tsx_events_attrs;
intel_pmu_pebs_data_source_skl(pmem);
if (boot_cpu_has(X86_FEATURE_TSX_FORCE_ABORT)) {
/*
* Processors with CPUID.RTM_ALWAYS_ABORT have TSX deprecated by default.
* TSX force abort hooks are not required on these systems. Only deploy
* workaround when microcode has not enabled X86_FEATURE_RTM_ALWAYS_ABORT.
*/
if (boot_cpu_has(X86_FEATURE_TSX_FORCE_ABORT) &&
!boot_cpu_has(X86_FEATURE_RTM_ALWAYS_ABORT)) {
x86_pmu.flags |= PMU_FL_TFA;
x86_pmu.get_event_constraints = tfa_get_event_constraints;
x86_pmu.enable_all = intel_tfa_pmu_enable_all;