The following commit has been merged into the perf/core branch of tip: Commit-ID: 16b48c3f5ed85b8017526b1acacf5115461b489a Gitweb: https://git.kernel.org/tip/16b48c3f5ed85b8017526b1acacf5115461b489a Author: Sandipan Das <sandipan.das@xxxxxxx> AuthorDate: Thu, 19 May 2022 15:33:32 +05:30 Committer: Peter Zijlstra <peterz@xxxxxxxxxxxxx> CommitterDate: Mon, 13 Jun 2022 10:15:13 +02:00 perf/x86/amd/uncore: Detect available DF counters If AMD Performance Monitoring Version 2 (PerfMonV2) is supported, use CPUID leaf 0x80000022 EBX to detect the number of Data Fabric (DF) PMCs. This offers more flexibility if the counts change in later processor families. Signed-off-by: Sandipan Das <sandipan.das@xxxxxxx> Signed-off-by: Peter Zijlstra (Intel) <peterz@xxxxxxxxxxxxx> Link: https://lore.kernel.org/r/bac7b2806561e03f2acc7fdc9db94f102df80e1d.1652954372.git.sandipan.das@xxxxxxx --- arch/x86/events/amd/uncore.c | 10 ++++++++++ arch/x86/include/asm/perf_event.h | 3 +++ 2 files changed, 13 insertions(+) diff --git a/arch/x86/events/amd/uncore.c b/arch/x86/events/amd/uncore.c index c3e218d..233dd40 100644 --- a/arch/x86/events/amd/uncore.c +++ b/arch/x86/events/amd/uncore.c @@ -30,6 +30,7 @@ #undef pr_fmt #define pr_fmt(fmt) "amd_uncore: " fmt +static int pmu_version; static int num_counters_llc; static int num_counters_nb; static bool l3_mask; @@ -629,6 +630,7 @@ static int __init amd_uncore_init(void) { struct attribute **df_attr = amd_uncore_df_format_attr; struct attribute **l3_attr = amd_uncore_l3_format_attr; + union cpuid_0x80000022_ebx ebx; int ret = -ENODEV; if (boot_cpu_data.x86_vendor != X86_VENDOR_AMD && @@ -638,6 +640,9 @@ static int __init amd_uncore_init(void) if (!boot_cpu_has(X86_FEATURE_TOPOEXT)) return -ENODEV; + if (boot_cpu_has(X86_FEATURE_PERFMON_V2)) + pmu_version = 2; + num_counters_nb = NUM_COUNTERS_NB; num_counters_llc = NUM_COUNTERS_L2; if (boot_cpu_data.x86 >= 0x17) { @@ -666,6 +671,11 @@ static int __init amd_uncore_init(void) if (ret) goto fail_nb; + if (pmu_version >= 2) { + ebx.full = cpuid_ebx(EXT_PERFMON_DEBUG_FEATURES); + num_counters_nb = ebx.split.num_df_pmc; + } + pr_info("%d %s %s counters detected\n", num_counters_nb, boot_cpu_data.x86_vendor == X86_VENDOR_HYGON ? "HYGON" : "", amd_nb_pmu.name); diff --git a/arch/x86/include/asm/perf_event.h b/arch/x86/include/asm/perf_event.h index 409725e..af157aa 100644 --- a/arch/x86/include/asm/perf_event.h +++ b/arch/x86/include/asm/perf_event.h @@ -194,6 +194,9 @@ union cpuid_0x80000022_ebx { struct { /* Number of Core Performance Counters */ unsigned int num_core_pmc:4; + unsigned int reserved:6; + /* Number of Data Fabric Counters */ + unsigned int num_df_pmc:6; } split; unsigned int full; };
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