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| author | Like Xu <like.xu@linux.intel.com> | 2020-06-13 16:09:48 +0800 |
|---|---|---|
| committer | Peter Zijlstra <peterz@infradead.org> | 2020-07-02 15:51:46 +0200 |
| commit | b2d6504761a50b9493eb4b20f6e188b673f20c32 (patch) | |
| tree | 32db6c3766c09fcb0a371e5a6a71737fc92dc155 /arch/x86/events | |
| parent | 027440b5d426a51f33b515bbd236cc479d1e051f (diff) | |
| download | linux-b2d6504761a50b9493eb4b20f6e188b673f20c32.tar.gz linux-b2d6504761a50b9493eb4b20f6e188b673f20c32.tar.bz2 linux-b2d6504761a50b9493eb4b20f6e188b673f20c32.zip | |
perf/x86/lbr: Add interface to get LBR information
The LBR records msrs are model specific. The perf subsystem has already
obtained the base addresses of LBR records based on the cpu model.
Therefore, an interface is added to allow callers outside the perf
subsystem to obtain these LBR information. It's useful for hypervisors
to emulate the LBR feature for guests with less code.
Signed-off-by: Like Xu <like.xu@linux.intel.com>
Signed-off-by: Wei Wang <wei.w.wang@intel.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://lkml.kernel.org/r/20200613080958.132489-4-like.xu@linux.intel.com
Diffstat (limited to 'arch/x86/events')
| -rw-r--r-- | arch/x86/events/intel/lbr.c | 20 |
1 files changed, 20 insertions, 0 deletions
diff --git a/arch/x86/events/intel/lbr.c b/arch/x86/events/intel/lbr.c index 65113b16804a..2ed3f2a51bdf 100644 --- a/arch/x86/events/intel/lbr.c +++ b/arch/x86/events/intel/lbr.c @@ -1343,3 +1343,23 @@ void intel_pmu_lbr_init_knl(void) if (x86_pmu.intel_cap.lbr_format == LBR_FORMAT_LIP) x86_pmu.intel_cap.lbr_format = LBR_FORMAT_EIP_FLAGS; } + +/** + * x86_perf_get_lbr - get the LBR records information + * + * @lbr: the caller's memory to store the LBR records information + * + * Returns: 0 indicates the LBR info has been successfully obtained + */ +int x86_perf_get_lbr(struct x86_pmu_lbr *lbr) +{ + int lbr_fmt = x86_pmu.intel_cap.lbr_format; + + lbr->nr = x86_pmu.lbr_nr; + lbr->from = x86_pmu.lbr_from; + lbr->to = x86_pmu.lbr_to; + lbr->info = (lbr_fmt == LBR_FORMAT_INFO) ? MSR_LBR_INFO_0 : 0; + + return 0; +} +EXPORT_SYMBOL_GPL(x86_perf_get_lbr); |