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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