perf tools: Add optional support for libpfm4

This patch links perf with the libpfm4 library if it is available and
LIBPFM4 is passed to the build. The libpfm4 library contains hardware
event tables for all processors supported by perf_events. It is a helper
library that helps convert from a symbolic event name to the event
encoding required by the underlying kernel interface. This library is
open-source and available from: http://perfmon2.sf.net.

With this patch, it is possible to specify full hardware events by name.
Hardware filters are also supported. Events must be specified via the
--pfm-events and not -e option. Both options are active at the same time
and it is possible to mix and match:

  $ perf stat --pfm-events inst_retired:any_p:c=1:i -e cycles ....

One needs to explicitely ask for its inclusion by using the LIBPFM4 make
command line option, ie its opt-in rather than opt-out of feature
detection and build support.

Signed-off-by: Stephane Eranian <eranian@google.com>
Reviewed-by: Ian Rogers <irogers@google.com>
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Alexei Starovoitov <ast@kernel.org>
Cc: Alexey Budankov <alexey.budankov@linux.intel.com>
Cc: Andi Kleen <ak@linux.intel.com>
Cc: Andrii Nakryiko <andriin@fb.com>
Cc: Daniel Borkmann <daniel@iogearbox.net>
Cc: Florian Fainelli <f.fainelli@gmail.com>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Igor Lubashev <ilubashe@akamai.com>
Cc: Jin Yao <yao.jin@linux.intel.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Jiwei Sun <jiwei.sun@windriver.com>
Cc: John Garry <john.garry@huawei.com>
Cc: Kan Liang <kan.liang@linux.intel.com>
Cc: Leo Yan <leo.yan@linaro.org>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Martin KaFai Lau <kafai@fb.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Yonghong Song <yhs@fb.com>
Cc: bpf@vger.kernel.org
Cc: netdev@vger.kernel.org
Cc: yuzhoujian <yuzhoujian@didichuxing.com>
Link: http://lore.kernel.org/lkml/20200505182943.218248-2-irogers@google.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

7 files changed, 349 insertions, 8 deletions

diff --git a/tools/perf/util/Build b/tools/perf/util/Build
index 880fcdd1ab11..329f12345da0 100644
--- a/tools/perf/util/Build
+++ b/tools/perf/util/Build
@@ -183,6 +183,8 @@ perf-$(CONFIG_LIBBPF) += bpf-event.o
 
 perf-$(CONFIG_CXX) += c++/
 
+perf-$(CONFIG_LIBPFM4) += pfm.o
+
 CFLAGS_config.o   += -DETC_PERFCONFIG="BUILD_STR($(ETC_PERFCONFIG_SQ))"
 CFLAGS_llvm-utils.o += -DPERF_INCLUDE_DIR="BUILD_STR($(perf_include_dir_SQ))"
 
diff --git a/tools/perf/util/evsel.c b/tools/perf/util/evsel.c
index 95b525149949..96e5171dce41 100644
--- a/tools/perf/util/evsel.c
+++ b/tools/perf/util/evsel.c
@@ -2417,7 +2417,7 @@ bool evsel__fallback(struct evsel *evsel, int err, char *msg, size_t msgsize)
 
 		/* Is there already the separator in the name. */
 		if (strchr(name, '/') ||
-		    strchr(name, ':'))
+		    (strchr(name, ':') && !evsel->is_libpfm_event))
 			sep = "";
 
 		if (asprintf(&new_name, "%s%su", name, sep) < 0)
diff --git a/tools/perf/util/evsel.h b/tools/perf/util/evsel.h
index 3a1a814a0319..0f963c2a88a5 100644
--- a/tools/perf/util/evsel.h
+++ b/tools/perf/util/evsel.h
@@ -76,6 +76,7 @@ struct evsel {
 	bool			ignore_missing_thread;
 	bool			forced_leader;
 	bool			use_uncore_alias;
+	bool			is_libpfm_event;
 	/* parse modifier helper */
 	int			exclude_GH;
 	int			sample_read;
diff --git a/tools/perf/util/parse-events.c b/tools/perf/util/parse-events.c
index 27b8e49d690e..3decbb203846 100644
--- a/tools/perf/util/parse-events.c
+++ b/tools/perf/util/parse-events.c
@@ -36,6 +36,7 @@
 #include "metricgroup.h"
 #include "util/evsel_config.h"
 #include "util/event.h"
+#include "util/pfm.h"
 
 #define MAX_NAME_LEN 100
 
@@ -345,6 +346,7 @@ static char *get_config_name(struct list_head *head_terms)
 static struct evsel *
 __add_event(struct list_head *list, int *idx,
 	    struct perf_event_attr *attr,
+	    bool init_attr,
 	    char *name, struct perf_pmu *pmu,
 	    struct list_head *config_terms, bool auto_merge_stats,
 	    const char *cpu_list)
@@ -353,7 +355,8 @@ __add_event(struct list_head *list, int *idx,
 	struct perf_cpu_map *cpus = pmu ? pmu->cpus :
 			       cpu_list ? perf_cpu_map__new(cpu_list) : NULL;
 
-	event_attr_init(attr);
+	if (init_attr)
+		event_attr_init(attr);
 
 	evsel = evsel__new_idx(attr, *idx);
 	if (!evsel)
@@ -371,15 +374,25 @@ __add_event(struct list_head *list, int *idx,
 	if (config_terms)
 		list_splice(config_terms, &evsel->config_terms);
 
-	list_add_tail(&evsel->core.node, list);
+	if (list)
+		list_add_tail(&evsel->core.node, list);
+
 	return evsel;
 }
 
+struct evsel *parse_events__add_event(int idx, struct perf_event_attr *attr,
+					char *name, struct perf_pmu *pmu)
+{
+	return __add_event(NULL, &idx, attr, false, name, pmu, NULL, false,
+			   NULL);
+}
+
 static int add_event(struct list_head *list, int *idx,
 		     struct perf_event_attr *attr, char *name,
 		     struct list_head *config_terms)
 {
-	return __add_event(list, idx, attr, name, NULL, config_terms, false, NULL) ? 0 : -ENOMEM;
+	return __add_event(list, idx, attr, true, name, NULL, config_terms,
+			   false, NULL) ? 0 : -ENOMEM;
 }
 
 static int add_event_tool(struct list_head *list, int *idx,
@@ -391,7 +404,8 @@ static int add_event_tool(struct list_head *list, int *idx,
 		.config = PERF_COUNT_SW_DUMMY,
 	};
 
-	evsel = __add_event(list, idx, &attr, NULL, NULL, NULL, false, "0");
+	evsel = __add_event(list, idx, &attr, true, NULL, NULL, NULL, false,
+			    "0");
 	if (!evsel)
 		return -ENOMEM;
 	evsel->tool_event = tool_event;
@@ -1458,8 +1472,8 @@ int parse_events_add_pmu(struct parse_events_state *parse_state,
 
 	if (!head_config) {
 		attr.type = pmu->type;
-		evsel = __add_event(list, &parse_state->idx, &attr, NULL, pmu, NULL,
-				    auto_merge_stats, NULL);
+		evsel = __add_event(list, &parse_state->idx, &attr, true, NULL,
+				    pmu, NULL, auto_merge_stats, NULL);
 		if (evsel) {
 			evsel->pmu_name = name ? strdup(name) : NULL;
 			evsel->use_uncore_alias = use_uncore_alias;
@@ -1514,7 +1528,7 @@ int parse_events_add_pmu(struct parse_events_state *parse_state,
 		return -EINVAL;
 	}
 
-	evsel = __add_event(list, &parse_state->idx, &attr,
+	evsel = __add_event(list, &parse_state->idx, &attr, true,
 			    get_config_name(head_config), pmu,
 			    &config_terms, auto_merge_stats, NULL);
 	if (evsel) {
@@ -2846,6 +2860,8 @@ void print_events(const char *event_glob, bool name_only, bool quiet_flag,
 	print_sdt_events(NULL, NULL, name_only);
 
 	metricgroup__print(true, true, NULL, name_only, details_flag);
+
+	print_libpfm_events(name_only, long_desc);
 }
 
 int parse_events__is_hardcoded_term(struct parse_events_term *term)
diff --git a/tools/perf/util/parse-events.h b/tools/perf/util/parse-events.h
index d60510e0609f..1fe23a2f9b36 100644
--- a/tools/perf/util/parse-events.h
+++ b/tools/perf/util/parse-events.h
@@ -17,6 +17,7 @@ struct evlist;
 struct parse_events_error;
 
 struct option;
+struct perf_pmu;
 
 struct tracepoint_path {
 	char *system;
@@ -188,6 +189,9 @@ int parse_events_add_pmu(struct parse_events_state *parse_state,
 			 bool auto_merge_stats,
 			 bool use_alias);
 
+struct evsel *parse_events__add_event(int idx, struct perf_event_attr *attr,
+					char *name, struct perf_pmu *pmu);
+
 int parse_events_multi_pmu_add(struct parse_events_state *parse_state,
 			       char *str,
 			       struct list_head **listp);
diff --git a/tools/perf/util/pfm.c b/tools/perf/util/pfm.c
new file mode 100644
index 000000000000..d735acb6c29c
--- /dev/null
+++ b/tools/perf/util/pfm.c
@@ -0,0 +1,281 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Support for libpfm4 event encoding.
+ *
+ * Copyright 2020 Google LLC.
+ */
+#include "util/cpumap.h"
+#include "util/debug.h"
+#include "util/event.h"
+#include "util/evlist.h"
+#include "util/evsel.h"
+#include "util/parse-events.h"
+#include "util/pmu.h"
+#include "util/pfm.h"
+
+#include <string.h>
+#include <linux/kernel.h>
+#include <perfmon/pfmlib_perf_event.h>
+
+static void libpfm_initialize(void)
+{
+	int ret;
+
+	ret = pfm_initialize();
+	if (ret != PFM_SUCCESS) {
+		ui__warning("libpfm failed to initialize: %s\n",
+			pfm_strerror(ret));
+	}
+}
+
+int parse_libpfm_events_option(const struct option *opt, const char *str,
+			int unset __maybe_unused)
+{
+	struct evlist *evlist = *(struct evlist **)opt->value;
+	struct perf_event_attr attr;
+	struct perf_pmu *pmu;
+	struct evsel *evsel, *grp_leader = NULL;
+	char *p, *q, *p_orig;
+	const char *sep;
+	int grp_evt = -1;
+	int ret;
+
+	libpfm_initialize();
+
+	p_orig = p = strdup(str);
+	if (!p)
+		return -1;
+	/*
+	 * force loading of the PMU list
+	 */
+	perf_pmu__scan(NULL);
+
+	for (q = p; strsep(&p, ",{}"); q = p) {
+		sep = p ? str + (p - p_orig - 1) : "";
+		if (*sep == '{') {
+			if (grp_evt > -1) {
+				ui__error(
+					"nested event groups not supported\n");
+				goto error;
+			}
+			grp_evt++;
+		}
+
+		/* no event */
+		if (*q == '\0')
+			continue;
+
+		memset(&attr, 0, sizeof(attr));
+		event_attr_init(&attr);
+
+		ret = pfm_get_perf_event_encoding(q, PFM_PLM0|PFM_PLM3,
+						&attr, NULL, NULL);
+
+		if (ret != PFM_SUCCESS) {
+			ui__error("failed to parse event %s : %s\n", str,
+				  pfm_strerror(ret));
+			goto error;
+		}
+
+		pmu = perf_pmu__find_by_type((unsigned int)attr.type);
+		evsel = parse_events__add_event(evlist->core.nr_entries,
+						&attr, q, pmu);
+		if (evsel == NULL)
+			goto error;
+
+		evsel->is_libpfm_event = true;
+
+		evlist__add(evlist, evsel);
+
+		if (grp_evt == 0)
+			grp_leader = evsel;
+
+		if (grp_evt > -1) {
+			evsel->leader = grp_leader;
+			grp_leader->core.nr_members++;
+			grp_evt++;
+		}
+
+		if (*sep == '}') {
+			if (grp_evt < 0) {
+				ui__error(
+				   "cannot close a non-existing event group\n");
+				goto error;
+			}
+			evlist->nr_groups++;
+			grp_leader = NULL;
+			grp_evt = -1;
+		}
+	}
+	return 0;
+error:
+	free(p_orig);
+	return -1;
+}
+
+static const char *srcs[PFM_ATTR_CTRL_MAX] = {
+	[PFM_ATTR_CTRL_UNKNOWN] = "???",
+	[PFM_ATTR_CTRL_PMU] = "PMU",
+	[PFM_ATTR_CTRL_PERF_EVENT] = "perf_event",
+};
+
+static void
+print_attr_flags(pfm_event_attr_info_t *info)
+{
+	int n = 0;
+
+	if (info->is_dfl) {
+		printf("[default] ");
+		n++;
+	}
+
+	if (info->is_precise) {
+		printf("[precise] ");
+		n++;
+	}
+
+	if (!n)
+		printf("- ");
+}
+
+static void
+print_libpfm_events_detailed(pfm_event_info_t *info, bool long_desc)
+{
+	pfm_event_attr_info_t ainfo;
+	const char *src;
+	int j, ret;
+
+	ainfo.size = sizeof(ainfo);
+
+	printf("  %s\n", info->name);
+	printf("    [%s]\n", info->desc);
+	if (long_desc) {
+		if (info->equiv)
+			printf("      Equiv: %s\n", info->equiv);
+
+		printf("      Code  : 0x%"PRIx64"\n", info->code);
+	}
+	pfm_for_each_event_attr(j, info) {
+		ret = pfm_get_event_attr_info(info->idx, j,
+					      PFM_OS_PERF_EVENT_EXT, &ainfo);
+		if (ret != PFM_SUCCESS)
+			continue;
+
+		if (ainfo.type == PFM_ATTR_UMASK) {
+			printf("      %s:%s\n", info->name, ainfo.name);
+			printf("        [%s]\n", ainfo.desc);
+		}
+
+		if (!long_desc)
+			continue;
+
+		if (ainfo.ctrl >= PFM_ATTR_CTRL_MAX)
+			ainfo.ctrl = PFM_ATTR_CTRL_UNKNOWN;
+
+		src = srcs[ainfo.ctrl];
+		switch (ainfo.type) {
+		case PFM_ATTR_UMASK:
+			printf("        Umask : 0x%02"PRIx64" : %s: ",
+				ainfo.code, src);
+			print_attr_flags(&ainfo);
+			putchar('\n');
+			break;
+		case PFM_ATTR_MOD_BOOL:
+			printf("      Modif : %s: [%s] : %s (boolean)\n", src,
+				ainfo.name, ainfo.desc);
+			break;
+		case PFM_ATTR_MOD_INTEGER:
+			printf("      Modif : %s: [%s] : %s (integer)\n", src,
+				ainfo.name, ainfo.desc);
+			break;
+		case PFM_ATTR_NONE:
+		case PFM_ATTR_RAW_UMASK:
+		case PFM_ATTR_MAX:
+		default:
+			printf("      Attr  : %s: [%s] : %s\n", src,
+				ainfo.name, ainfo.desc);
+		}
+	}
+}
+
+/*
+ * list all pmu::event:umask, pmu::event
+ * printed events may not be all valid combinations of umask for an event
+ */
+static void
+print_libpfm_events_raw(pfm_pmu_info_t *pinfo, pfm_event_info_t *info)
+{
+	pfm_event_attr_info_t ainfo;
+	int j, ret;
+	bool has_umask = false;
+
+	ainfo.size = sizeof(ainfo);
+
+	pfm_for_each_event_attr(j, info) {
+		ret = pfm_get_event_attr_info(info->idx, j,
+					      PFM_OS_PERF_EVENT_EXT, &ainfo);
+		if (ret != PFM_SUCCESS)
+			continue;
+
+		if (ainfo.type != PFM_ATTR_UMASK)
+			continue;
+
+		printf("%s::%s:%s\n", pinfo->name, info->name, ainfo.name);
+		has_umask = true;
+	}
+	if (!has_umask)
+		printf("%s::%s\n", pinfo->name, info->name);
+}
+
+void print_libpfm_events(bool name_only, bool long_desc)
+{
+	pfm_event_info_t info;
+	pfm_pmu_info_t pinfo;
+	int i, p, ret;
+
+	libpfm_initialize();
+
+	/* initialize to zero to indicate ABI version */
+	info.size  = sizeof(info);
+	pinfo.size = sizeof(pinfo);
+
+	if (!name_only)
+		puts("\nList of pre-defined events (to be used in --pfm-events):\n");
+
+	pfm_for_all_pmus(p) {
+		bool printed_pmu = false;
+
+		ret = pfm_get_pmu_info(p, &pinfo);
+		if (ret != PFM_SUCCESS)
+			continue;
+
+		/* only print events that are supported by host HW */
+		if (!pinfo.is_present)
+			continue;
+
+		/* handled by perf directly */
+		if (pinfo.pmu == PFM_PMU_PERF_EVENT)
+			continue;
+
+		for (i = pinfo.first_event; i != -1;
+		     i = pfm_get_event_next(i)) {
+
+			ret = pfm_get_event_info(i, PFM_OS_PERF_EVENT_EXT,
+						&info);
+			if (ret != PFM_SUCCESS)
+				continue;
+
+			if (!name_only && !printed_pmu) {
+				printf("%s:\n", pinfo.name);
+				printed_pmu = true;
+			}
+
+			if (!name_only)
+				print_libpfm_events_detailed(&info, long_desc);
+			else
+				print_libpfm_events_raw(&pinfo, &info);
+		}
+		if (!name_only && printed_pmu)
+			putchar('\n');
+	}
+}
diff --git a/tools/perf/util/pfm.h b/tools/perf/util/pfm.h
new file mode 100644
index 000000000000..7d70dda87012
--- /dev/null
+++ b/tools/perf/util/pfm.h
@@ -0,0 +1,37 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+/*
+ * Support for libpfm4 event encoding.
+ *
+ * Copyright 2020 Google LLC.
+ */
+#ifndef __PERF_PFM_H
+#define __PERF_PFM_H
+
+#include <subcmd/parse-options.h>
+
+#ifdef HAVE_LIBPFM
+int parse_libpfm_events_option(const struct option *opt, const char *str,
+			int unset);
+
+void print_libpfm_events(bool name_only, bool long_desc);
+
+#else
+#include <linux/compiler.h>
+
+static inline int parse_libpfm_events_option(
+	const struct option *opt __maybe_unused,
+	const char *str __maybe_unused,
+	int unset __maybe_unused)
+{
+	return 0;
+}
+
+static inline void print_libpfm_events(bool name_only __maybe_unused,
+				       bool long_desc __maybe_unused)
+{
+}
+
+#endif
+
+
+#endif /* __PERF_PFM_H */