perf/tool: Add PMU event alias support

Add support to specify alias term within the event description.

The definition of pmu event alias is located at:

  ${sysfs_mount}/bus/event_source/devices/${pmu}/events/

Each file in the 'events' directory defines a event alias. Its contents
are like:

  config=1,config1=2

Using pmu event alias, an event can be now specified like:

  uncore/CLOCKTICKS/ or uncore/event=CLOCKTICKS/

Signed-off-by: Zheng Yan <zheng.z.yan@intel.com>
[ Cleaned it up. ]
Signed-off-by: Jiri Olsa <jolsa@redhat.com>
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: http://lkml.kernel.org/r/1339741902-8449-13-git-send-email-zheng.z.yan@intel.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>

4 files changed, 188 insertions, 1 deletions

diff --git a/tools/perf/util/parse-events.c b/tools/perf/util/parse-events.c
index d002170adb3f..3339424cc421 100644
--- a/tools/perf/util/parse-events.c
+++ b/tools/perf/util/parse-events.c
@@ -701,6 +701,9 @@ int parse_events_add_pmu(struct list_head **list, int *idx,
 
         memset(&attr, 0, sizeof(attr));
 
+        if (perf_pmu__check_alias(pmu, head_config))
+                return -EINVAL;
+
         /*
          * Configure hardcoded terms first, no need to check
          * return value when called with fail == 0 ;)
@@ -1143,6 +1146,13 @@ int parse_events__term_str(struct parse_events__term **term,
                         config, str, 0);
 }
 
+int parse_events__term_clone(struct parse_events__term **new,
+                             struct parse_events__term *term)
+{
+        return new_term(new, term->type_val, term->type_term, term->config,
+                        term->val.str, term->val.num);
+}
+
 void parse_events__free_terms(struct list_head *terms)
 {
         struct parse_events__term *term, *h;
diff --git a/tools/perf/util/parse-events.h b/tools/perf/util/parse-events.h
index 9896edadbe62..a2c71684f6a4 100644
--- a/tools/perf/util/parse-events.h
+++ b/tools/perf/util/parse-events.h
@@ -78,6 +78,8 @@ int parse_events__term_num(struct parse_events__term **_term,
                            int type_term, char *config, long num);
 int parse_events__term_str(struct parse_events__term **_term,
                            int type_term, char *config, char *str);
+int parse_events__term_clone(struct parse_events__term **new,
+                             struct parse_events__term *term);
 void parse_events__free_terms(struct list_head *terms);
 int parse_events_modifier(struct list_head *list, char *str);
 int parse_events_add_tracepoint(struct list_head **list, int *idx,
diff --git a/tools/perf/util/pmu.c b/tools/perf/util/pmu.c
index a119a5371699..74d0948ec368 100644
--- a/tools/perf/util/pmu.c
+++ b/tools/perf/util/pmu.c
@@ -80,6 +80,114 @@ static int pmu_format(char *name, struct list_head *format)
         return 0;
 }
 
+static int perf_pmu__new_alias(struct list_head *list, char *name, FILE *file)
+{
+        struct perf_pmu__alias *alias;
+        char buf[256];
+        int ret;
+
+        ret = fread(buf, 1, sizeof(buf), file);
+        if (ret == 0)
+                return -EINVAL;
+        buf[ret] = 0;
+
+        alias = malloc(sizeof(*alias));
+        if (!alias)
+                return -ENOMEM;
+
+        INIT_LIST_HEAD(&alias->terms);
+        ret = parse_events_terms(&alias->terms, buf);
+        if (ret) {
+                free(alias);
+                return ret;
+        }
+
+        alias->name = strdup(name);
+        list_add_tail(&alias->list, list);
+        return 0;
+}
+
+/*
+ * Process all the sysfs attributes located under the directory
+ * specified in 'dir' parameter.
+ */
+static int pmu_aliases_parse(char *dir, struct list_head *head)
+{
+        struct dirent *evt_ent;
+        DIR *event_dir;
+        int ret = 0;
+
+        event_dir = opendir(dir);
+        if (!event_dir)
+                return -EINVAL;
+
+        while (!ret && (evt_ent = readdir(event_dir))) {
+                char path[PATH_MAX];
+                char *name = evt_ent->d_name;
+                FILE *file;
+
+                if (!strcmp(name, ".") || !strcmp(name, ".."))
+                        continue;
+
+                snprintf(path, PATH_MAX, "%s/%s", dir, name);
+
+                ret = -EINVAL;
+                file = fopen(path, "r");
+                if (!file)
+                        break;
+                ret = perf_pmu__new_alias(head, name, file);
+                fclose(file);
+        }
+
+        closedir(event_dir);
+        return ret;
+}
+
+/*
+ * Reading the pmu event aliases definition, which should be located at:
+ * /sys/bus/event_source/devices/<dev>/events as sysfs group attributes.
+ */
+static int pmu_aliases(char *name, struct list_head *head)
+{
+        struct stat st;
+        char path[PATH_MAX];
+        const char *sysfs;
+
+        sysfs = sysfs_find_mountpoint();
+        if (!sysfs)
+                return -1;
+
+        snprintf(path, PATH_MAX,
+                 "%s/bus/event_source/devices/%s/events", sysfs, name);
+
+        if (stat(path, &st) < 0)
+                return -1;
+
+        if (pmu_aliases_parse(path, head))
+                return -1;
+
+        return 0;
+}
+
+static int pmu_alias_terms(struct perf_pmu__alias *alias,
+                           struct list_head *terms)
+{
+        struct parse_events__term *term, *clone;
+        LIST_HEAD(list);
+        int ret;
+
+        list_for_each_entry(term, &alias->terms, list) {
+                ret = parse_events__term_clone(&clone, term);
+                if (ret) {
+                        parse_events__free_terms(&list);
+                        return ret;
+                }
+                list_add_tail(&clone->list, &list);
+        }
+        list_splice(&list, terms);
+        return 0;
+}
+
 /*
  * Reading/parsing the default pmu type value, which should be
  * located at:
@@ -118,6 +226,7 @@ static struct perf_pmu *pmu_lookup(char *name)
 {
         struct perf_pmu *pmu;
         LIST_HEAD(format);
+        LIST_HEAD(aliases);
         __u32 type;
 
         /*
@@ -135,8 +244,12 @@ static struct perf_pmu *pmu_lookup(char *name)
         if (!pmu)
                 return NULL;
 
+        pmu_aliases(name, &aliases);
+
         INIT_LIST_HEAD(&pmu->format);
+        INIT_LIST_HEAD(&pmu->aliases);
         list_splice(&format, &pmu->format);
+        list_splice(&aliases, &pmu->aliases);
         pmu->name = strdup(name);
         pmu->type = type;
         return pmu;
@@ -279,6 +392,59 @@ int perf_pmu__config(struct perf_pmu *pmu, struct perf_event_attr *attr,
         return pmu_config(&pmu->format, attr, head_terms);
 }
 
+static struct perf_pmu__alias *pmu_find_alias(struct perf_pmu *pmu,
+                                              struct parse_events__term *term)
+{
+        struct perf_pmu__alias *alias;
+        char *name;
+
+        if (parse_events__is_hardcoded_term(term))
+                return NULL;
+
+        if (term->type_val == PARSE_EVENTS__TERM_TYPE_NUM) {
+                if (term->val.num != 1)
+                        return NULL;
+                if (pmu_find_format(&pmu->format, term->config))
+                        return NULL;
+                name = term->config;
+        } else if (term->type_val == PARSE_EVENTS__TERM_TYPE_STR) {
+                if (strcasecmp(term->config, "event"))
+                        return NULL;
+                name = term->val.str;
+        } else {
+                return NULL;
+        }
+
+        list_for_each_entry(alias, &pmu->aliases, list) {
+                if (!strcasecmp(alias->name, name))
+                        return alias;
+        }
+        return NULL;
+}
+
+/*
+ * Find alias in the terms list and replace it with the terms
+ * defined for the alias
+ */
+int perf_pmu__check_alias(struct perf_pmu *pmu, struct list_head *head_terms)
+{
+        struct parse_events__term *term, *h;
+        struct perf_pmu__alias *alias;
+        int ret;
+
+        list_for_each_entry_safe(term, h, head_terms, list) {
+                alias = pmu_find_alias(pmu, term);
+                if (!alias)
+                        continue;
+                ret = pmu_alias_terms(alias, &term->list);
+                if (ret)
+                        return ret;
+                list_del(&term->list);
+                free(term);
+        }
+        return 0;
+}
+
 int perf_pmu__new_format(struct list_head *list, char *name,
                          int config, unsigned long *bits)
 {
diff --git a/tools/perf/util/pmu.h b/tools/perf/util/pmu.h
index 68c0db965e1f..535f2c5258ab 100644
--- a/tools/perf/util/pmu.h
+++ b/tools/perf/util/pmu.h
@@ -19,17 +19,26 @@ struct perf_pmu__format {
         struct list_head list;
 };
 
+struct perf_pmu__alias {
+        char *name;
+        struct list_head terms;
+        struct list_head list;
+};
+
 struct perf_pmu {
         char *name;
         __u32 type;
         struct list_head format;
+        struct list_head aliases;
         struct list_head list;
 };
 
 struct perf_pmu *perf_pmu__find(char *name);
 int perf_pmu__config(struct perf_pmu *pmu, struct perf_event_attr *attr,
                      struct list_head *head_terms);
-
+int perf_pmu__check_alias(struct perf_pmu *pmu, struct list_head *head_terms);
+struct list_head *perf_pmu__alias(struct perf_pmu *pmu,
+                                struct list_head *head_terms);
 int perf_pmu_wrap(void);
 void perf_pmu_error(struct list_head *list, char *name, char const *msg);