[PATCH 1/1] perf/x86/intel: Add perf core PMU support for Intel Knights Landing

* [PATCH 1/1] perf/x86/intel: Add perf core PMU support for Intel Knights Landing
@ 2015-12-07 22:28 Harish Chegondi
  2015-12-08  8:37 ` Peter Zijlstra
  2016-01-06 18:53 ` [tip:perf/core] " tip-bot for Harish Chegondi
  0 siblings, 2 replies; 6+ messages in thread
From: Harish Chegondi @ 2015-12-07 22:28 UTC (permalink / raw)
  To: linux-kernel, mingo, a.p.zijlstra
  Cc: Harish Chegondi, Harish Chegondi, Andi Kleen, Kan Liang,
	Lukasz Anaczkowski

Knights Landing core is based on Silvermont core with several differences.
Like Silvermont, Knights Landing has 8 pairs of LBR MSRs. However, the
LBR MSRs addresses match those of the Xeon cores' first 8 pairs of LBR MSRs
Unlike Silvermont, Knights Landing supports hyperthreading. Knights Landing
offcore response events config register mask is different from that of the
Silvermont.

This patch was developed based on a patch from Andi Kleen.

For more details, please refer to the public document:
https://software.intel.com/sites/default/files/managed/15/8d/IntelXeonPhi%E2%84%A2x200ProcessorPerformanceMonitoringReferenceManual_Volume1_Registers_v0%206.pdf

Signed-off-by: Harish Chegondi <harish.chegondi@intel.com>
Cc: Andi Kleen <andi.kleen@intel.com>
Cc: Kan Liang <kan.liang@intel.com>
Cc: Lukasz Anaczkowski <lukasz.anaczkowski@intel.com>
---
 arch/x86/kernel/cpu/perf_event.h           |  2 +
 arch/x86/kernel/cpu/perf_event_intel.c     | 62 ++++++++++++++++++++++++++++++
 arch/x86/kernel/cpu/perf_event_intel_lbr.c | 14 +++++++
 3 files changed, 78 insertions(+)

diff --git a/arch/x86/kernel/cpu/perf_event.h b/arch/x86/kernel/cpu/perf_event.h
index 799e6bd..dbaf026 100644
--- a/arch/x86/kernel/cpu/perf_event.h
+++ b/arch/x86/kernel/cpu/perf_event.h
@@ -901,6 +901,8 @@ void intel_pmu_lbr_init_hsw(void);
 
 void intel_pmu_lbr_init_skl(void);
 
+void intel_pmu_lbr_init_knl(void);
+
 int intel_pmu_setup_lbr_filter(struct perf_event *event);
 
 void intel_pt_interrupt(void);
diff --git a/arch/x86/kernel/cpu/perf_event_intel.c b/arch/x86/kernel/cpu/perf_event_intel.c
index 33b4b67..cf0a136 100644
--- a/arch/x86/kernel/cpu/perf_event_intel.c
+++ b/arch/x86/kernel/cpu/perf_event_intel.c
@@ -185,6 +185,14 @@ struct event_constraint intel_skl_event_constraints[] = {
 	EVENT_CONSTRAINT_END
 };
 
+static struct extra_reg intel_knl_extra_regs[] __read_mostly = {
+	INTEL_UEVENT_EXTRA_REG(0x01b7,
+			       MSR_OFFCORE_RSP_0, 0x7f9ffbffffull, RSP_0),
+	INTEL_UEVENT_EXTRA_REG(0x02b7,
+			       MSR_OFFCORE_RSP_1, 0x3f9ffbffffull, RSP_1),
+	EVENT_EXTRA_END
+};
+
 static struct extra_reg intel_snb_extra_regs[] __read_mostly = {
 	/* must define OFFCORE_RSP_X first, see intel_fixup_er() */
 	INTEL_UEVENT_EXTRA_REG(0x01b7, MSR_OFFCORE_RSP_0, 0x3f807f8fffull, RSP_0),
@@ -1457,6 +1465,42 @@ static __initconst const u64 slm_hw_cache_event_ids
  },
 };
 
+#define KNL_OT_L2_HITE		BIT_ULL(19) /* Other Tile L2 Hit */
+#define KNL_OT_L2_HITF		BIT_ULL(20) /* Other Tile L2 Hit */
+#define KNL_MCDRAM_LOCAL	BIT_ULL(21)
+#define KNL_MCDRAM_FAR		BIT_ULL(22)
+#define KNL_DDR_LOCAL		BIT_ULL(23)
+#define KNL_DDR_FAR		BIT_ULL(24)
+#define KNL_DRAM_ANY		(KNL_MCDRAM_LOCAL | KNL_MCDRAM_FAR | \
+				    KNL_DDR_LOCAL | KNL_DDR_FAR)
+#define KNL_L2_READ		SLM_DMND_READ
+#define KNL_L2_WRITE		SLM_DMND_WRITE
+#define KNL_L2_PREFETCH		SLM_DMND_PREFETCH
+#define KNL_L2_ACCESS		SLM_LLC_ACCESS
+#define KNL_L2_MISS		(KNL_OT_L2_HITE | KNL_OT_L2_HITF | \
+				   KNL_DRAM_ANY | SNB_SNP_ANY | \
+						  SNB_NON_DRAM)
+
+static __initconst const u64 knl_hw_cache_extra_regs
+				[PERF_COUNT_HW_CACHE_MAX]
+				[PERF_COUNT_HW_CACHE_OP_MAX]
+				[PERF_COUNT_HW_CACHE_RESULT_MAX] = {
+	[C(LL)] = {
+		[C(OP_READ)] = {
+			[C(RESULT_ACCESS)] = KNL_L2_READ | KNL_L2_ACCESS,
+			[C(RESULT_MISS)]   = 0,
+		},
+		[C(OP_WRITE)] = {
+			[C(RESULT_ACCESS)] = KNL_L2_WRITE | KNL_L2_ACCESS,
+			[C(RESULT_MISS)]   = KNL_L2_WRITE | KNL_L2_MISS,
+		},
+		[C(OP_PREFETCH)] = {
+			[C(RESULT_ACCESS)] = KNL_L2_PREFETCH | KNL_L2_ACCESS,
+			[C(RESULT_MISS)]   = KNL_L2_PREFETCH | KNL_L2_MISS,
+		},
+	},
+};
+
 /*
  * Use from PMIs where the LBRs are already disabled.
  */
@@ -3511,6 +3555,24 @@ __init int intel_pmu_init(void)
 		pr_cont("Broadwell events, ");
 		break;
 
+	case 87: /* Knights Landing Xeon Phi */
+		memcpy(hw_cache_event_ids,
+		       slm_hw_cache_event_ids, sizeof(hw_cache_event_ids));
+		memcpy(hw_cache_extra_regs,
+		       knl_hw_cache_extra_regs, sizeof(hw_cache_extra_regs));
+		intel_pmu_lbr_init_knl();
+
+		x86_pmu.event_constraints = intel_slm_event_constraints;
+		x86_pmu.pebs_constraints = intel_slm_pebs_event_constraints;
+		x86_pmu.extra_regs = intel_knl_extra_regs;
+
+		/* all extra regs are per-cpu when HT is on */
+		x86_pmu.flags |= PMU_FL_HAS_RSP_1;
+		x86_pmu.flags |= PMU_FL_NO_HT_SHARING;
+
+		pr_cont("Knights Landing events, ");
+		break;
+
 	case 78: /* 14nm Skylake Mobile */
 	case 94: /* 14nm Skylake Desktop */
 		x86_pmu.late_ack = true;
diff --git a/arch/x86/kernel/cpu/perf_event_intel_lbr.c b/arch/x86/kernel/cpu/perf_event_intel_lbr.c
index e2fad0c..50bf2de 100644
--- a/arch/x86/kernel/cpu/perf_event_intel_lbr.c
+++ b/arch/x86/kernel/cpu/perf_event_intel_lbr.c
@@ -1043,3 +1043,17 @@ void __init intel_pmu_lbr_init_atom(void)
 	 */
 	pr_cont("8-deep LBR, ");
 }
+
+/* Knights Landing */
+void intel_pmu_lbr_init_knl(void)
+{
+	x86_pmu.lbr_nr	   = 8;
+	x86_pmu.lbr_tos    = MSR_LBR_TOS;
+	x86_pmu.lbr_from   = MSR_LBR_NHM_FROM;
+	x86_pmu.lbr_to     = MSR_LBR_NHM_TO;
+
+	x86_pmu.lbr_sel_mask = LBR_SEL_MASK;
+	x86_pmu.lbr_sel_map  = snb_lbr_sel_map;
+
+	pr_cont("8-deep LBR, ");
+}
-- 
2.1.2.330.g565301e


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