[PATCH v1 13/15] perf tp_pmu: Add event APIs

[Ian Rogers]

Add event APIs for the tracepoint PMU allowing things like perf list
to function using it. For perf list add the tracepoint format in the
long description (shown with -v).

Signed-off-by: Ian Rogers <irogers@xxxxxxxxxx>
---
 tools/perf/util/pmu.c    |   7 +++
 tools/perf/util/tp_pmu.c | 114 +++++++++++++++++++++++++++++++++++++++
 tools/perf/util/tp_pmu.h |   7 +++
 3 files changed, 128 insertions(+)

diff --git a/tools/perf/util/pmu.c b/tools/perf/util/pmu.c
index 4164c2278051..d4be0195ea74 100644
--- a/tools/perf/util/pmu.c
+++ b/tools/perf/util/pmu.c
@@ -23,6 +23,7 @@
 #include "hwmon_pmu.h"
 #include "pmus.h"
 #include "tool_pmu.h"
+#include "tp_pmu.h"
 #include <util/pmu-bison.h>
 #include <util/pmu-flex.h>
 #include "parse-events.h"
@@ -1977,6 +1978,8 @@ bool perf_pmu__have_event(struct perf_pmu *pmu, const char *name)
 		return false;
 	if (perf_pmu__is_tool(pmu) && tool_pmu__skip_event(name))
 		return false;
+	if (perf_pmu__is_tracepoint(pmu))
+		return tp_pmu__have_event(pmu, name);
 	if (perf_pmu__is_hwmon(pmu))
 		return hwmon_pmu__have_event(pmu, name);
 	if (perf_pmu__find_alias(pmu, name, /*load=*/ true) != NULL)
@@ -1990,6 +1993,8 @@ size_t perf_pmu__num_events(struct perf_pmu *pmu)
 {
 	size_t nr;
 
+	if (perf_pmu__is_tracepoint(pmu))
+		return tp_pmu__num_events(pmu);
 	if (perf_pmu__is_hwmon(pmu))
 		return hwmon_pmu__num_events(pmu);
 
@@ -2058,6 +2063,8 @@ int perf_pmu__for_each_event(struct perf_pmu *pmu, bool skip_duplicate_pmus,
 	struct hashmap_entry *entry;
 	size_t bkt;
 
+	if (perf_pmu__is_tracepoint(pmu))
+		return tp_pmu__for_each_event(pmu, state, cb);
 	if (perf_pmu__is_hwmon(pmu))
 		return hwmon_pmu__for_each_event(pmu, state, cb);
 
diff --git a/tools/perf/util/tp_pmu.c b/tools/perf/util/tp_pmu.c
index fd83164f8763..9d68a1da17f6 100644
--- a/tools/perf/util/tp_pmu.c
+++ b/tools/perf/util/tp_pmu.c
@@ -1,5 +1,6 @@
 // SPDX-License-Identifier: (LGPL-2.1 OR BSD-2-Clause)
 #include "tp_pmu.h"
+#include "pmus.h"
 #include <api/fs/fs.h>
 #include <api/fs/tracing_path.h>
 #include <api/io_dir.h>
@@ -93,3 +94,116 @@ int tp_pmu__for_each_tp_sys(void *state, tp_sys_callback cb)
 	close(events_dir.dirfd);
 	return ret;
 }
+
+bool perf_pmu__is_tracepoint(const struct perf_pmu *pmu)
+{
+	return pmu->type == PERF_TYPE_TRACEPOINT;
+}
+
+struct for_each_event_args {
+	void *state;
+	pmu_event_callback cb;
+	const struct perf_pmu *pmu;
+};
+
+static int for_each_event_cb(void *state, const char *sys_name, const char *evt_name)
+{
+	struct for_each_event_args *args = state;
+	char name[2 * FILENAME_MAX + 2];
+	/* 16 possible hex digits and 22 other characters and \0. */
+	char encoding[16 + 22];
+	char *format = NULL;
+	size_t format_size;
+	struct pmu_event_info info = {
+		.pmu = args->pmu,
+		.pmu_name = args->pmu->name,
+		.event_type_desc = "Tracepoint event",
+	};
+	char *tp_dir = get_events_file(sys_name);
+	char path[PATH_MAX];
+	int id, err;
+
+	if (!tp_dir)
+		return -1;
+
+	scnprintf(path, sizeof(path), "%s/%s/id", tp_dir, evt_name);
+	err = filename__read_int(path, &id);
+	if (err == 0) {
+		snprintf(encoding, sizeof(encoding), "tracepoint/config=0x%x/", id);
+		info.encoding_desc = encoding;
+	}
+
+	scnprintf(path, sizeof(path), "%s/%s/format", tp_dir, evt_name);
+	put_events_file(tp_dir);
+	err = filename__read_str(path, &format, &format_size);
+	if (err == 0) {
+		info.long_desc = format;
+		for (size_t i = 0 ; i < format_size; i++) {
+			/* Swap tabs to spaces due to some rendering issues. */
+			if (format[i] == '\t')
+				format[i] = ' ';
+		}
+	}
+	snprintf(name, sizeof(name), "%s:%s", sys_name, evt_name);
+	info.name = name;
+	err = args->cb(args->state, &info);
+	free(format);
+	return err;
+}
+
+static int for_each_event_sys_cb(void *state, const char *sys_name)
+{
+	return tp_pmu__for_each_tp_event(sys_name, state, for_each_event_cb);
+}
+
+int tp_pmu__for_each_event(struct perf_pmu *pmu, void *state, pmu_event_callback cb)
+{
+	struct for_each_event_args args = {
+		.state = state,
+		.cb = cb,
+		.pmu = pmu,
+	};
+
+	return tp_pmu__for_each_tp_sys(&args, for_each_event_sys_cb);
+}
+
+static int num_events_cb(void *state, const char *sys_name __maybe_unused,
+			 const char *evt_name __maybe_unused)
+{
+	size_t *count = state;
+
+	(*count)++;
+	return 0;
+}
+
+static int num_events_sys_cb(void *state, const char *sys_name)
+{
+	return tp_pmu__for_each_tp_event(sys_name, state, num_events_cb);
+}
+
+size_t tp_pmu__num_events(struct perf_pmu *pmu __maybe_unused)
+{
+	size_t count = 0;
+
+	tp_pmu__for_each_tp_sys(&count, num_events_sys_cb);
+	return count;
+}
+
+bool tp_pmu__have_event(struct perf_pmu *pmu __maybe_unused, const char *name)
+{
+	char *dup_name, *colon;
+	int id;
+
+	if (strchr(name, ':') == NULL)
+		return false;
+
+	dup_name = strdup(name);
+	if (!dup_name)
+		return false;
+
+	colon = strchr(dup_name, ':');
+	*colon = '\0';
+	id = tp_pmu__id(dup_name, colon + 1);
+	free(dup_name);
+	return id >= 0;
+}
diff --git a/tools/perf/util/tp_pmu.h b/tools/perf/util/tp_pmu.h
index 49537303bd73..30456bd6943d 100644
--- a/tools/perf/util/tp_pmu.h
+++ b/tools/perf/util/tp_pmu.h
@@ -2,6 +2,8 @@
 #ifndef __TP_PMU_H
 #define __TP_PMU_H
 
+#include "pmu.h"
+
 typedef int (*tp_sys_callback)(void *state, const char *sys_name);
 typedef int (*tp_event_callback)(void *state, const char *sys_name, const char *evt_name);
 
@@ -9,4 +11,9 @@ int tp_pmu__id(const char *sys, const char *name);
 int tp_pmu__for_each_tp_event(const char *sys, void *state, tp_event_callback cb);
 int tp_pmu__for_each_tp_sys(void *state, tp_sys_callback cb);
 
+bool perf_pmu__is_tracepoint(const struct perf_pmu *pmu);
+int tp_pmu__for_each_event(struct perf_pmu *pmu, void *state, pmu_event_callback cb);
+size_t tp_pmu__num_events(struct perf_pmu *pmu);
+bool tp_pmu__have_event(struct perf_pmu *pmu, const char *name);
+
 #endif /* __TP_PMU_H */
-- 
2.50.0.rc0.642.g800a2b2222-goog