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| author | Sandipan Das <sandipan.das@amd.com> | 2022-08-11 17:59:53 +0530 |
|---|---|---|
| committer | Peter Zijlstra <peterz@infradead.org> | 2022-08-27 00:05:43 +0200 |
| commit | 703fb765f48897214e3eb110f35dddec80682f60 (patch) | |
| tree | f23cd920b092433d819d3fa160d540cfd0129f18 /arch/x86/events/perf_event.h | |
| parent | 257449c6a50298bd21dcabd644f66a0296b78532 (diff) | |
| download | linux-703fb765f48897214e3eb110f35dddec80682f60.tar.bz2 | |
perf/x86/amd/lbr: Detect LbrExtV2 support
AMD Last Branch Record Extension Version 2 (LbrExtV2) is driven by Core PMC
overflows. It records recently taken branches up to the moment when the PMC
overflow occurs.
Detect the feature during PMU initialization and set the branch stack depth
using CPUID leaf 0x80000022 EBX.
Signed-off-by: Sandipan Das <sandipan.das@amd.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://lore.kernel.org/r/fc6e45378ada258f1bab79b0de6e05c393a8f1dd.1660211399.git.sandipan.das@amd.com
Diffstat (limited to 'arch/x86/events/perf_event.h')
| -rw-r--r-- | arch/x86/events/perf_event.h | 2 |
1 files changed, 2 insertions, 0 deletions
diff --git a/arch/x86/events/perf_event.h b/arch/x86/events/perf_event.h index 5deb34e42bbd..82e8a6d87ade 100644 --- a/arch/x86/events/perf_event.h +++ b/arch/x86/events/perf_event.h @@ -1232,6 +1232,8 @@ static inline bool fixed_counter_disabled(int i, struct pmu *pmu) int amd_pmu_init(void); +int amd_pmu_lbr_init(void); + #ifdef CONFIG_PERF_EVENTS_AMD_BRS #define AMD_FAM19H_BRS_EVENT 0xc4 /* RETIRED_TAKEN_BRANCH_INSTRUCTIONS */ |