[PATCH 04/21] perf/x86/intel/lbr: Add pointer for LBR read

kan.liang
2020-06-19T14:07:57Z

The method to read Architectural LBRs is different from previous
model-specific LBR. Perf has to implement a different function.

A function pointer for LBR read is introduced. Perf should initialize
the corresponding function at boot time, and avoid checking lbr_format
at run time.

The current 64-bit LBR read function is set as default.

Signed-off-by: Kan Liang <kan.liang@linux.intel.com>
---
arch/x86/events/intel/core.c | 6 +++++-
arch/x86/events/intel/lbr.c | 9 +++------
arch/x86/events/perf_event.h | 5 +++++
3 files changed, 13 insertions(+), 7 deletions(-)

diff --git a/arch/x86/events/intel/core.c b/arch/x86/events/intel/core.c
index 995acdb..03b17d5 100644
--- a/arch/x86/events/intel/core.c
+++ b/arch/x86/events/intel/core.c
@@ -3955,6 +3955,7 @@ static __initconst const struct x86_pmu core_pmu = {
.lbr_enable = intel_pmu_lbr_enable,
.lbr_disable = intel_pmu_lbr_disable,
.lbr_reset = intel_pmu_lbr_reset_64,
+ .lbr_read = intel_pmu_lbr_read_64,
};

static __initconst const struct x86_pmu intel_pmu = {
@@ -4004,6 +4005,7 @@ static __initconst const struct x86_pmu intel_pmu = {
.lbr_enable = intel_pmu_lbr_enable,
.lbr_disable = intel_pmu_lbr_disable,
.lbr_reset = intel_pmu_lbr_reset_64,
+ .lbr_read = intel_pmu_lbr_read_64,
};

static __init void intel_clovertown_quirk(void)
@@ -4630,8 +4632,10 @@ __init int intel_pmu_init(void)
x86_pmu.intel_cap.capabilities = capabilities;
}

- if (x86_pmu.intel_cap.lbr_format == LBR_FORMAT_32)
+ if (x86_pmu.intel_cap.lbr_format == LBR_FORMAT_32) {
x86_pmu.lbr_reset = intel_pmu_lbr_reset_32;
+ x86_pmu.lbr_read = intel_pmu_lbr_read_32;
+ }

intel_ds_init();

diff --git a/arch/x86/events/intel/lbr.c b/arch/x86/events/intel/lbr.c
index ff320d1..d762c76 100644
--- a/arch/x86/events/intel/lbr.c
+++ b/arch/x86/events/intel/lbr.c
@@ -542,7 +542,7 @@ void intel_pmu_lbr_disable_all(void)
x86_pmu.lbr_disable();
}

-static void intel_pmu_lbr_read_32(struct cpu_hw_events *cpuc)
+void intel_pmu_lbr_read_32(struct cpu_hw_events *cpuc)
{
unsigned long mask = x86_pmu.lbr_nr - 1;
u64 tos = intel_pmu_lbr_tos();
@@ -579,7 +579,7 @@ static void intel_pmu_lbr_read_32(struct cpu_hw_events *cpuc)
* is the same as the linear address, allowing us to merge the LIP and EIP
* LBR formats.
*/
-static void intel_pmu_lbr_read_64(struct cpu_hw_events *cpuc)
+void intel_pmu_lbr_read_64(struct cpu_hw_events *cpuc)
{
bool need_info = false, call_stack = false;
unsigned long mask = x86_pmu.lbr_nr - 1;
@@ -683,10 +683,7 @@ void intel_pmu_lbr_read(void)
if (!cpuc->lbr_users || cpuc->lbr_users == cpuc->lbr_pebs_users)
return;

- if (x86_pmu.intel_cap.lbr_format == LBR_FORMAT_32)
- intel_pmu_lbr_read_32(cpuc);
- else
- intel_pmu_lbr_read_64(cpuc);
+ x86_pmu.lbr_read(cpuc);

intel_pmu_lbr_filter(cpuc);
}
diff --git a/arch/x86/events/perf_event.h b/arch/x86/events/perf_event.h
index abf95ef..e2e086c0 100644
--- a/arch/x86/events/perf_event.h
+++ b/arch/x86/events/perf_event.h
@@ -693,6 +693,7 @@ struct x86_pmu {
void (*lbr_enable)(bool pmi);
void (*lbr_disable)(void);
void (*lbr_reset)(void);
+ void (*lbr_read)(struct cpu_hw_events *cpuc);

/*
* Intel PT/LBR/BTS are exclusive
@@ -1086,6 +1087,10 @@ void intel_pmu_lbr_disable(void);

void intel_pmu_lbr_read(void);

+void intel_pmu_lbr_read_32(struct cpu_hw_events *cpuc);
+
+void intel_pmu_lbr_read_64(struct cpu_hw_events *cpuc);
+
void intel_pmu_lbr_init_core(void);

void intel_pmu_lbr_init_nhm(void);
--
2.7.4