Commit f8ad6018 authored by James Clark's avatar James Clark Committed by Arnaldo Carvalho de Melo
Browse files

perf pmu: 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: default avatarLeo Yan <leo.yan@linaro.org>
Signed-off-by: default avatarJames Clark <james.clark@arm.com>
Acked-by: default avatarSuzuki Poulouse <suzuki.poulose@arm.com>
Tested-by: default avatarTanmay Jagdale <tanmay@marvell.com>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Bharat Bhushan <bbhushan2@marvell.com>
Cc: George Cherian <gcherian@marvell.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: John Garry <john.g.garry@oracle.com>
Cc: Linu Cherian <lcherian@marvell.com>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Mathieu Poirier <mathieu.poirier@linaro.org>
Cc: Mike Leach <mike.leach@linaro.org>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Sunil Kovvuri Goutham <sgoutham@marvell.com>
Cc: Will Deacon <will@kernel.org>
Cc: coresight@lists.linaro.org
Cc: linux-arm-kernel@lists.infradead.org
Link: https://lore.kernel.org/r/20230120143702.4035046-2-james.clark@arm.com


Signed-off-by: default avatarArnaldo Carvalho de Melo <acme@redhat.com>
parent 4cbd5334

tools/perf/arch/arm/util/auxtrace.c

+2 −3
Original line number Diff line number Diff line
@@ -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;

	}

tools/perf/arch/arm64/util/pmu.c

+2 −2
Original line number Diff line number Diff line
@@ -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.

tools/perf/arch/x86/util/pmu.c

+2 −10
Original line number Diff line number Diff line
@@ -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;

tools/perf/util/pmu.c

+41 −69
Original line number Diff line number Diff line
@@ -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);

}

tools/perf/util/pmu.h

+4 −1
Original line number Diff line number Diff line
@@ -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 */