[PATCH 1/1] x86, perf: add LBR filter support for SLM

[kan . liang]

From: Kan Liang <kan.liang@xxxxxxxxx>

LBR filtering is also supported on the Silvermont and Airmont
microarchitectures. The layout of MSR_LBR_SELECT is same as Nehalem.

Signed-off-by: Kan Liang <kan.liang@xxxxxxxxx>
---
 arch/x86/events/intel/core.c |  2 +-
 arch/x86/events/intel/lbr.c  | 18 ++++++++++++++++++
 arch/x86/events/perf_event.h |  2 ++
 3 files changed, 21 insertions(+), 1 deletion(-)

diff --git a/arch/x86/events/intel/core.c b/arch/x86/events/intel/core.c
index 931c13a..14d27e3 100644
--- a/arch/x86/events/intel/core.c
+++ b/arch/x86/events/intel/core.c
@@ -3581,7 +3581,7 @@ __init int intel_pmu_init(void)
 		memcpy(hw_cache_extra_regs, slm_hw_cache_extra_regs,
 		       sizeof(hw_cache_extra_regs));
 
-		intel_pmu_lbr_init_atom();
+		intel_pmu_lbr_init_slm();
 
 		x86_pmu.event_constraints = intel_slm_event_constraints;
 		x86_pmu.pebs_constraints = intel_slm_pebs_event_constraints;
diff --git a/arch/x86/events/intel/lbr.c b/arch/x86/events/intel/lbr.c
index ad26ca7..317e29e 100644
--- a/arch/x86/events/intel/lbr.c
+++ b/arch/x86/events/intel/lbr.c
@@ -1058,6 +1058,24 @@ void __init intel_pmu_lbr_init_atom(void)
 	pr_cont("8-deep LBR, ");
 }
 
+/* slm */
+void __init intel_pmu_lbr_init_slm(void)
+{
+	x86_pmu.lbr_nr	   = 8;
+	x86_pmu.lbr_tos    = MSR_LBR_TOS;
+	x86_pmu.lbr_from   = MSR_LBR_CORE_FROM;
+	x86_pmu.lbr_to     = MSR_LBR_CORE_TO;
+
+	x86_pmu.lbr_sel_mask = LBR_SEL_MASK;
+	x86_pmu.lbr_sel_map  = nhm_lbr_sel_map;
+
+	/*
+	 * SW branch filter usage:
+	 * - compensate for lack of HW filter
+	 */
+	pr_cont("8-deep LBR, ");
+}
+
 /* Knights Landing */
 void intel_pmu_lbr_init_knl(void)
 {
diff --git a/arch/x86/events/perf_event.h b/arch/x86/events/perf_event.h
index 8b78481..7d62a02 100644
--- a/arch/x86/events/perf_event.h
+++ b/arch/x86/events/perf_event.h
@@ -909,6 +909,8 @@ void intel_pmu_lbr_init_nhm(void);
 
 void intel_pmu_lbr_init_atom(void);
 
+void intel_pmu_lbr_init_slm(void);
+
 void intel_pmu_lbr_init_snb(void);
 
 void intel_pmu_lbr_init_hsw(void);
-- 
2.5.0