Commit 16b48c3f authored by Sandipan Das's avatar Sandipan Das Committed by Peter Zijlstra
Browse files

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: default avatarSandipan Das <sandipan.das@amd.com>
Signed-off-by: default avatarPeter Zijlstra (Intel) <peterz@infradead.org>
Link: https://lore.kernel.org/r/bac7b2806561e03f2acc7fdc9db94f102df80e1d.1652954372.git.sandipan.das@amd.com
parent 847f3268

arch/x86/events/amd/uncore.c

+10 −0
Original line number Diff line number Diff line
@@ -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);

arch/x86/include/asm/perf_event.h

+3 −0
Original line number Diff line number Diff line
@@ -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;

};