linux-kernel - [tip: perf/core] perf/x86/intel: Support Architectural PerfMon Extension leaf

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Date:   Mon, 09 Jan 2023 17:02:08 -0000
From:   "tip-bot2 for Kan Liang" <tip-bot2@...utronix.de>
To:     linux-tip-commits@...r.kernel.org
Cc:     Kan Liang <kan.liang@...ux.intel.com>,
        Ingo Molnar <mingo@...nel.org>,
        Peter Zijlstra <peterz@...radead.org>, x86@...nel.org,
        linux-kernel@...r.kernel.org
Subject: [tip: perf/core] perf/x86/intel: Support Architectural PerfMon Extension leaf

The following commit has been merged into the perf/core branch of tip:

Commit-ID:     eb467aaac21e133a3d01c48c0a6bf43756b06e78
Gitweb:        https://git.kernel.org/tip/eb467aaac21e133a3d01c48c0a6bf43756b06e78
Author:        Kan Liang <kan.liang@...ux.intel.com>
AuthorDate:    Wed, 04 Jan 2023 12:13:45 -08:00
Committer:     Ingo Molnar <mingo@...nel.org>
CommitterDate: Mon, 09 Jan 2023 12:22:08 +01:00

perf/x86/intel: Support Architectural PerfMon Extension leaf

The new CPUID leaf 0x23 reports the "true view" of PMU resources.

The sub-leaf 1 reports the available general-purpose counters and fixed
counters. Update the number of counters and fixed counters when the
sub-leaf is detected.

Signed-off-by: Kan Liang <kan.liang@...ux.intel.com>
Signed-off-by: Ingo Molnar <mingo@...nel.org>
Acked-by: Peter Zijlstra <peterz@...radead.org>
Link: https://lore.kernel.org/r/20230104201349.1451191-5-kan.liang@linux.intel.com
---
 arch/x86/events/intel/core.c      | 22 ++++++++++++++++++++++
 arch/x86/include/asm/perf_event.h |  8 ++++++++
 2 files changed, 30 insertions(+)

diff --git a/arch/x86/events/intel/core.c b/arch/x86/events/intel/core.c
index a5678ab..29d2d04 100644
--- a/arch/x86/events/intel/core.c
+++ b/arch/x86/events/intel/core.c
@@ -4588,6 +4588,25 @@ static void flip_smm_bit(void *data)
 	}
 }
 
+static void intel_pmu_check_num_counters(int *num_counters,
+					 int *num_counters_fixed,
+					 u64 *intel_ctrl, u64 fixed_mask);
+
+static void update_pmu_cap(struct x86_hybrid_pmu *pmu)
+{
+	unsigned int sub_bitmaps = cpuid_eax(ARCH_PERFMON_EXT_LEAF);
+	unsigned int eax, ebx, ecx, edx;
+
+	if (sub_bitmaps & ARCH_PERFMON_NUM_COUNTER_LEAF_BIT) {
+		cpuid_count(ARCH_PERFMON_EXT_LEAF, ARCH_PERFMON_NUM_COUNTER_LEAF,
+			    &eax, &ebx, &ecx, &edx);
+		pmu->num_counters = fls(eax);
+		pmu->num_counters_fixed = fls(ebx);
+		intel_pmu_check_num_counters(&pmu->num_counters, &pmu->num_counters_fixed,
+					     &pmu->intel_ctrl, ebx);
+	}
+}
+
 static bool init_hybrid_pmu(int cpu)
 {
 	struct cpu_hw_events *cpuc = &per_cpu(cpu_hw_events, cpu);
@@ -4613,6 +4632,9 @@ static bool init_hybrid_pmu(int cpu)
 	if (!cpumask_empty(&pmu->supported_cpus))
 		goto end;
 
+	if (this_cpu_has(X86_FEATURE_ARCH_PERFMON_EXT))
+		update_pmu_cap(pmu);
+
 	if (!check_hw_exists(&pmu->pmu, pmu->num_counters, pmu->num_counters_fixed))
 		return false;
 
diff --git a/arch/x86/include/asm/perf_event.h b/arch/x86/include/asm/perf_event.h
index 5d0f689..6496bdb 100644
--- a/arch/x86/include/asm/perf_event.h
+++ b/arch/x86/include/asm/perf_event.h
@@ -160,6 +160,14 @@ union cpuid10_edx {
 };
 
 /*
+ * Intel "Architectural Performance Monitoring extension" CPUID
+ * detection/enumeration details:
+ */
+#define ARCH_PERFMON_EXT_LEAF			0x00000023
+#define ARCH_PERFMON_NUM_COUNTER_LEAF_BIT	0x1
+#define ARCH_PERFMON_NUM_COUNTER_LEAF		0x1
+
+/*
  * Intel Architectural LBR CPUID detection/enumeration details:
  */
 union cpuid28_eax {