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Message-Id: <20230120143702.4035046-2-james.clark@arm.com>
Date: Fri, 20 Jan 2023 14:36:54 +0000
From: James Clark <james.clark@....com>
To: linux-perf-users@...r.kernel.org, tanmay@...vell.com,
leo.yan@...aro.org, mike.leach@...aro.org
Cc: sgoutham@...vell.com, gcherian@...vell.com, lcherian@...vell.com,
bbhushan2@...vell.com, James Clark <james.clark@....com>,
Mathieu Poirier <mathieu.poirier@...aro.org>,
Suzuki K Poulose <suzuki.poulose@....com>,
John Garry <john.g.garry@...cle.com>,
Will Deacon <will@...nel.org>,
Peter Zijlstra <peterz@...radead.org>,
Ingo Molnar <mingo@...hat.com>,
Arnaldo Carvalho de Melo <acme@...nel.org>,
Mark Rutland <mark.rutland@....com>,
Alexander Shishkin <alexander.shishkin@...ux.intel.com>,
Jiri Olsa <jolsa@...nel.org>,
Namhyung Kim <namhyung@...nel.org>, coresight@...ts.linaro.org,
linux-arm-kernel@...ts.infradead.org, linux-kernel@...r.kernel.org
Subject: [PATCH v5 1/8] perf: Remove duplication around EVENT_SOURCE_DEVICE_PATH
The pattern for accessing EVENT_SOURCE_DEVICE_PATH is duplicated in a
few places, so add two utility functions to cover it. Also just use
perf_pmu__scan_file() instead of pmu_type() which already does the same
thing.
No functional changes.
Reviewed-by: Leo Yan <leo.yan@...aro.org>
Signed-off-by: James Clark <james.clark@....com>
---
tools/perf/arch/arm/util/auxtrace.c | 5 +-
tools/perf/arch/arm64/util/pmu.c | 4 +-
tools/perf/arch/x86/util/pmu.c | 12 +--
tools/perf/util/pmu.c | 110 +++++++++++-----------------
tools/perf/util/pmu.h | 5 +-
5 files changed, 51 insertions(+), 85 deletions(-)
diff --git a/tools/perf/arch/arm/util/auxtrace.c b/tools/perf/arch/arm/util/auxtrace.c
index deeb163999ce..adec6c9ee11d 100644
--- a/tools/perf/arch/arm/util/auxtrace.c
+++ b/tools/perf/arch/arm/util/auxtrace.c
@@ -55,17 +55,16 @@ static struct perf_pmu **find_all_arm_spe_pmus(int *nr_spes, int *err)
static struct perf_pmu **find_all_hisi_ptt_pmus(int *nr_ptts, int *err)
{
- const char *sysfs = sysfs__mountpoint();
struct perf_pmu **hisi_ptt_pmus = NULL;
struct dirent *dent;
char path[PATH_MAX];
DIR *dir = NULL;
int idx = 0;
- snprintf(path, PATH_MAX, "%s" EVENT_SOURCE_DEVICE_PATH, sysfs);
+ perf_pmu__event_source_devices_scnprintf(path, sizeof(path));
dir = opendir(path);
if (!dir) {
- pr_err("can't read directory '%s'\n", EVENT_SOURCE_DEVICE_PATH);
+ pr_err("can't read directory '%s'\n", path);
*err = -EINVAL;
return NULL;
}
diff --git a/tools/perf/arch/arm64/util/pmu.c b/tools/perf/arch/arm64/util/pmu.c
index 9e674cac5a73..801bf52e2ea6 100644
--- a/tools/perf/arch/arm64/util/pmu.c
+++ b/tools/perf/arch/arm64/util/pmu.c
@@ -44,8 +44,8 @@ double perf_pmu__cpu_slots_per_cycle(void)
struct perf_pmu *pmu = pmu__find_core_pmu();
if (pmu) {
- scnprintf(path, PATH_MAX,
- EVENT_SOURCE_DEVICE_PATH "%s/caps/slots", pmu->name);
+ perf_pmu__pathname_scnprintf(path, sizeof(path),
+ pmu->name, "caps/slots");
/*
* The value of slots is not greater than 32 bits, but sysfs__read_int
* can't read value with 0x prefix, so use sysfs__read_ull instead.
diff --git a/tools/perf/arch/x86/util/pmu.c b/tools/perf/arch/x86/util/pmu.c
index 74d69db1ea99..358340b34243 100644
--- a/tools/perf/arch/x86/util/pmu.c
+++ b/tools/perf/arch/x86/util/pmu.c
@@ -15,8 +15,6 @@
#include "../../../util/pmu.h"
#include "../../../util/fncache.h"
-#define TEMPLATE_ALIAS "%s/bus/event_source/devices/%s/alias"
-
struct pmu_alias {
char *name;
char *alias;
@@ -72,18 +70,14 @@ static int setup_pmu_alias_list(void)
char path[PATH_MAX];
DIR *dir;
struct dirent *dent;
- const char *sysfs = sysfs__mountpoint();
struct pmu_alias *pmu_alias;
char buf[MAX_PMU_NAME_LEN];
FILE *file;
int ret = -ENOMEM;
- if (!sysfs)
+ if (!perf_pmu__event_source_devices_scnprintf(path, sizeof(path)))
return -1;
- snprintf(path, PATH_MAX,
- "%s" EVENT_SOURCE_DEVICE_PATH, sysfs);
-
dir = opendir(path);
if (!dir)
return -errno;
@@ -93,9 +87,7 @@ static int setup_pmu_alias_list(void)
!strcmp(dent->d_name, ".."))
continue;
- snprintf(path, PATH_MAX,
- TEMPLATE_ALIAS, sysfs, dent->d_name);
-
+ perf_pmu__pathname_scnprintf(path, sizeof(path), dent->d_name, "alias");
if (!file_available(path))
continue;
diff --git a/tools/perf/util/pmu.c b/tools/perf/util/pmu.c
index cbb4fbf124bd..1edbb714ff32 100644
--- a/tools/perf/util/pmu.c
+++ b/tools/perf/util/pmu.c
@@ -108,14 +108,10 @@ int perf_pmu__format_parse(char *dir, struct list_head *head)
static int pmu_format(const char *name, struct list_head *format)
{
char path[PATH_MAX];
- const char *sysfs = sysfs__mountpoint();
- if (!sysfs)
+ if (!perf_pmu__pathname_scnprintf(path, sizeof(path), name, "format"))
return -1;
- snprintf(path, PATH_MAX,
- "%s" EVENT_SOURCE_DEVICE_PATH "%s/format", sysfs, name);
-
if (!file_available(path))
return 0;
@@ -514,14 +510,10 @@ static int pmu_aliases_parse(char *dir, struct list_head *head)
static int pmu_aliases(const char *name, struct list_head *head)
{
char path[PATH_MAX];
- const char *sysfs = sysfs__mountpoint();
- if (!sysfs)
+ if (!perf_pmu__pathname_scnprintf(path, sizeof(path), name, "events"))
return -1;
- snprintf(path, PATH_MAX,
- "%s/bus/event_source/devices/%s/events", sysfs, name);
-
if (!file_available(path))
return 0;
@@ -555,52 +547,16 @@ static int pmu_alias_terms(struct perf_pmu_alias *alias,
return 0;
}
-/*
- * Reading/parsing the default pmu type value, which should be
- * located at:
- * /sys/bus/event_source/devices/<dev>/type as sysfs attribute.
- */
-static int pmu_type(const char *name, __u32 *type)
-{
- char path[PATH_MAX];
- FILE *file;
- int ret = 0;
- const char *sysfs = sysfs__mountpoint();
-
- if (!sysfs)
- return -1;
-
- snprintf(path, PATH_MAX,
- "%s" EVENT_SOURCE_DEVICE_PATH "%s/type", sysfs, name);
-
- if (access(path, R_OK) < 0)
- return -1;
-
- file = fopen(path, "r");
- if (!file)
- return -EINVAL;
-
- if (1 != fscanf(file, "%u", type))
- ret = -1;
-
- fclose(file);
- return ret;
-}
-
/* Add all pmus in sysfs to pmu list: */
static void pmu_read_sysfs(void)
{
char path[PATH_MAX];
DIR *dir;
struct dirent *dent;
- const char *sysfs = sysfs__mountpoint();
- if (!sysfs)
+ if (!perf_pmu__event_source_devices_scnprintf(path, sizeof(path)))
return;
- snprintf(path, PATH_MAX,
- "%s" EVENT_SOURCE_DEVICE_PATH, sysfs);
-
dir = opendir(path);
if (!dir)
return;
@@ -697,14 +653,9 @@ static char *pmu_id(const char *name)
static int is_arm_pmu_core(const char *name)
{
char path[PATH_MAX];
- const char *sysfs = sysfs__mountpoint();
- if (!sysfs)
+ if (!perf_pmu__pathname_scnprintf(path, sizeof(path), name, "cpus"))
return 0;
-
- /* Look for cpu sysfs (specific to arm) */
- scnprintf(path, PATH_MAX, "%s/bus/event_source/devices/%s/cpus",
- sysfs, name);
return file_available(path);
}
@@ -970,11 +921,8 @@ static struct perf_pmu *pmu_lookup(const char *lookup_name)
return NULL;
/*
- * Check the type first to avoid unnecessary work.
+ * Check the aliases first to avoid unnecessary work.
*/
- if (pmu_type(name, &type))
- return NULL;
-
if (pmu_aliases(name, &aliases))
return NULL;
@@ -984,9 +932,14 @@ static struct perf_pmu *pmu_lookup(const char *lookup_name)
pmu->cpus = pmu_cpumask(name);
pmu->name = strdup(name);
+
if (!pmu->name)
goto err;
+ /* Read type, and ensure that type value is successfully assigned (return 1) */
+ if (perf_pmu__scan_file(pmu, "type", "%u", &type) != 1)
+ goto err;
+
alias_name = pmu_find_alias_name(name);
if (alias_name) {
pmu->alias_name = strdup(alias_name);
@@ -1787,16 +1740,11 @@ bool pmu_have_event(const char *pname, const char *name)
static FILE *perf_pmu__open_file(struct perf_pmu *pmu, const char *name)
{
char path[PATH_MAX];
- const char *sysfs;
- sysfs = sysfs__mountpoint();
- if (!sysfs)
+ if (!perf_pmu__pathname_scnprintf(path, sizeof(path), pmu->name, name) ||
+ !file_available(path))
return NULL;
- snprintf(path, PATH_MAX,
- "%s" EVENT_SOURCE_DEVICE_PATH "%s/%s", sysfs, pmu->name, name);
- if (!file_available(path))
- return NULL;
return fopen(path, "r");
}
@@ -1850,7 +1798,6 @@ int perf_pmu__caps_parse(struct perf_pmu *pmu)
{
struct stat st;
char caps_path[PATH_MAX];
- const char *sysfs = sysfs__mountpoint();
DIR *caps_dir;
struct dirent *evt_ent;
@@ -1859,12 +1806,9 @@ int perf_pmu__caps_parse(struct perf_pmu *pmu)
pmu->nr_caps = 0;
- if (!sysfs)
+ if (!perf_pmu__pathname_scnprintf(caps_path, sizeof(caps_path), pmu->name, "caps"))
return -1;
- snprintf(caps_path, PATH_MAX,
- "%s" EVENT_SOURCE_DEVICE_PATH "%s/caps", sysfs, pmu->name);
-
if (stat(caps_path, &st) < 0) {
pmu->caps_initialized = true;
return 0; /* no error if caps does not exist */
@@ -1999,3 +1943,31 @@ double __weak perf_pmu__cpu_slots_per_cycle(void)
{
return NAN;
}
+
+int perf_pmu__event_source_devices_scnprintf(char *pathname, size_t size)
+{
+ const char *sysfs = sysfs__mountpoint();
+
+ if (!sysfs)
+ return 0;
+ return scnprintf(pathname, size, "%s/bus/event_source/devices/", sysfs);
+}
+
+/*
+ * Fill 'buf' with the path to a file or folder in 'pmu_name' in
+ * sysfs. For example if pmu_name = "cs_etm" and 'filename' = "format"
+ * then pathname will be filled with
+ * "/sys/bus/event_source/devices/cs_etm/format"
+ *
+ * Return 0 if the sysfs mountpoint couldn't be found or if no
+ * characters were written.
+ */
+int perf_pmu__pathname_scnprintf(char *buf, size_t size,
+ const char *pmu_name, const char *filename)
+{
+ char base_path[PATH_MAX];
+
+ if (!perf_pmu__event_source_devices_scnprintf(base_path, sizeof(base_path)))
+ return 0;
+ return scnprintf(buf, size, "%s%s/%s", base_path, pmu_name, filename);
+}
diff --git a/tools/perf/util/pmu.h b/tools/perf/util/pmu.h
index fd414ba1d776..96d030c8b3b3 100644
--- a/tools/perf/util/pmu.h
+++ b/tools/perf/util/pmu.h
@@ -22,7 +22,6 @@ enum {
};
#define PERF_PMU_FORMAT_BITS 64
-#define EVENT_SOURCE_DEVICE_PATH "/bus/event_source/devices/"
#define CPUS_TEMPLATE_CPU "%s/bus/event_source/devices/%s/cpus"
#define MAX_PMU_NAME_LEN 128
@@ -260,4 +259,8 @@ int perf_pmu__cpus_match(struct perf_pmu *pmu, struct perf_cpu_map *cpus,
char *pmu_find_real_name(const char *name);
char *pmu_find_alias_name(const char *name);
double perf_pmu__cpu_slots_per_cycle(void);
+int perf_pmu__event_source_devices_scnprintf(char *pathname, size_t size);
+int perf_pmu__pathname_scnprintf(char *buf, size_t size,
+ const char *pmu_name, const char *filename);
+
#endif /* __PMU_H */
--
2.25.1
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