[RFC/PATCH 2/2] perf check: Add 'pmu' subcommand

[Namhyung Kim <namhyung@kernel.org>]

The 'perf check pmu' command will show information about PMUs in the
system like below:

  $ perf check pmu | head
  cpu_atom: type = 10
    core PMU: cpus = 16-27
    caps: branches = 32
    caps: max_precise = 3
    caps: pmu_name = alderlake_hybrid
  cpu_core: type = 4
    core PMU: cpus = 0-15
    caps: branches = 32
    caps: max_precise = 3
    caps: pmu_name = alderlake_hybrid

The -q option will make it print the name and type of PMUs only.  It
also takes arguments to show matching PMUs only.

  $ perf check pmu -q uncore
  uncore_arb_0: type = 27
  uncore_arb_1: type = 28
  uncore_cbox_0: type = 15
  uncore_cbox_1: type = 16
  uncore_cbox_2: type = 17
  uncore_cbox_3: type = 18
  uncore_cbox_4: type = 19
  uncore_cbox_5: type = 20
  uncore_cbox_6: type = 21
  uncore_cbox_7: type = 22
  uncore_cbox_8: type = 23
  uncore_cbox_9: type = 24
  uncore_cbox_10: type = 25
  uncore_cbox_11: type = 26
  uncore_clock: type = 29
  uncore_imc_free_running_0: type = 32
  uncore_imc_free_running_1: type = 33
  uncore_imc_0: type = 30
  uncore_imc_1: type = 31

Signed-off-by: Namhyung Kim <namhyung@kernel.org>
---
 tools/perf/Documentation/perf-check.txt | 12 +++++
 tools/perf/builtin-check.c              | 60 ++++++++++++++++++++++++-
 2 files changed, 71 insertions(+), 1 deletion(-)

diff --git a/tools/perf/Documentation/perf-check.txt b/tools/perf/Documentation/perf-check.txt
index 34dccc29d90d2fdf..2fa007698c0f0814 100644
--- a/tools/perf/Documentation/perf-check.txt
+++ b/tools/perf/Documentation/perf-check.txt
@@ -11,6 +11,7 @@ SYNOPSIS
 'perf check' [<options>]
 'perf check' {feature <feature_list>} [<options>]
 'perf check' {system <setting_list>} [<options>]
+'perf check' {pmu <name_list>} [<options>]
 
 DESCRIPTION
 -----------
@@ -26,6 +27,9 @@ is built-in, otherwise returns with exit status 1.
 If the subcommand 'system' is used, then system settins are printed on
 the standard output with explanation.
 
+If the subcommand 'pmu' is used, then available PMU information is printed
+on the standard output with explanation.
+
 SUBCOMMANDS
 -----------
 
@@ -88,6 +92,14 @@ SUBCOMMANDS
 		nmi_watchdog
 		kptr_restrict
 
+pmu::
+
+	Print PMU information available in the system.
+
+	Example Usage:
+		perf check pmu
+		perf check pmu <name>
+
 
 OPTIONS
 -------
diff --git a/tools/perf/builtin-check.c b/tools/perf/builtin-check.c
index 1c7c6bb5da5ccbf2..f3d034a94b1227c7 100644
--- a/tools/perf/builtin-check.c
+++ b/tools/perf/builtin-check.c
@@ -3,6 +3,8 @@
 #include "color.h"
 #include "util/debug.h"
 #include "util/header.h"
+#include "util/pmu.h"
+#include "util/pmus.h"
 #include <api/fs/fs.h>
 #include <tools/config.h>
 #include <stdbool.h>
@@ -10,13 +12,14 @@
 #include <string.h>
 #include <subcmd/parse-options.h>
 
-static const char * const check_subcommands[] = { "feature", "system", NULL };
+static const char * const check_subcommands[] = { "feature", "system", "pmu", NULL };
 static struct option check_options[] = {
 	OPT_BOOLEAN('q', "quiet", &quiet, "do not show any warnings or messages"),
 	OPT_END()
 };
 static struct option check_feature_options[] = { OPT_PARENT(check_options) };
 static struct option check_system_options[] = { OPT_PARENT(check_options) };
+static struct option check_pmu_options[] = { OPT_PARENT(check_options) };
 
 static const char *check_usage[] = { NULL, NULL };
 static const char *check_feature_usage[] = {
@@ -27,6 +30,10 @@ static const char *check_system_usage[] = {
 	"perf check system",
 	NULL
 };
+static const char *check_pmu_usage[] = {
+	"perf check pmu",
+	NULL
+};
 
 #define FEATURE_STATUS(name_, macro_) {    \
 	.name = name_,                     \
@@ -278,6 +285,55 @@ static int subcommand_system(int argc, const char **argv)
 	return 0;
 }
 
+/**
+ * Usage: 'perf check pmu <names>'
+ *
+ * Show PMU information.
+ */
+static int subcommand_pmu(int argc, const char **argv)
+{
+	struct perf_pmu *pmu = NULL;
+	struct perf_pmu_caps *caps;
+
+	argc = parse_options(argc, argv, check_pmu_options, check_pmu_usage, 0);
+
+	while ((pmu = perf_pmus__scan(pmu)) != NULL) {
+		if (argc) {
+			bool found = false;
+
+			/* only show entries match to command line arguments */
+			for (int k = 0; k < argc; k++) {
+				if (strstr(pmu->name, argv[k])) {
+					found = true;
+					break;
+				}
+			}
+			if (!found)
+				continue;
+		}
+
+		printf("%s: type = %u\n", pmu->name, pmu->type);
+		if (quiet)
+			continue;
+
+		if (pmu->is_core || pmu->is_uncore) {
+			printf("  %score PMU", pmu->is_uncore ? "un" : "");
+			if (!perf_cpu_map__is_empty(pmu->cpus)) {
+				printf(": %s = ", pmu->is_core ? "cpus" : "cpumask");
+				cpu_map__fprintf(pmu->cpus, stdout);
+			} else {
+				printf("\n");
+			}
+		}
+
+		perf_pmu__caps_parse(pmu);
+		list_for_each_entry(caps, &pmu->caps, list) {
+			printf("  caps: %s = %s\n", caps->name, caps->value);
+		}
+	}
+	return 0;
+}
+
 int cmd_check(int argc, const char **argv)
 {
 	argc = parse_options_subcommand(argc, argv, check_options,
@@ -290,6 +346,8 @@ int cmd_check(int argc, const char **argv)
 		return subcommand_feature(argc, argv);
 	if (strcmp(argv[0], "system") == 0)
 		return subcommand_system(argc, argv);
+	if (strcmp(argv[0], "pmu") == 0)
+		return subcommand_pmu(argc, argv);
 
 	/* If no subcommand matched above, print usage help */
 	pr_err("Unknown subcommand: %s\n", argv[0]);
-- 
2.51.0