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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@amd.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://lore.kernel.org/r/bac7b2806561e03f2acc7fdc9db94f102df80e1d.1652954372.git.sandipan.das@amd.com
This commit is contained in:
Sandipan Das 2022-05-19 15:33:32 +05:30 committed by Peter Zijlstra
parent 847f3268bb
commit 16b48c3f5e
2 changed files with 13 additions and 0 deletions
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10
arch/x86/events/amd/uncore.c
View File

@ -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);

3
arch/x86/include/asm/perf_event.h
View File

@ -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;
};