[PATCH v5 0/5] Hwmon PMUs

[PATCH v5 0/5] Hwmon PMUs

[Ian Rogers]

Following the convention of the tool PMU, create a hwmon PMU that
exposes hwmon data for reading. For example, the following shows
reading the CPU temperature and 2 fan speeds alongside the uncore
frequency:
```
$ perf stat -e temp_cpu,fan1,hwmon_thinkpad/fan2/,tool/num_cpus_online/ -M UNCORE_FREQ -I 1000
     1.001153138              52.00 'C   temp_cpu
     1.001153138              2,588 rpm  fan1
     1.001153138              2,482 rpm  hwmon_thinkpad/fan2/
     1.001153138                  8      tool/num_cpus_online/
     1.001153138      1,077,101,397      UNC_CLOCK.SOCKET                 #     1.08 UNCORE_FREQ
     1.001153138      1,012,773,595      duration_time
...
```

Additional data on the hwmon events is in perf list:
```
$ perf list
...
hwmon:
...
  temp_core_0 OR temp2
       [Temperature in unit coretemp named Core 0. crit=100'C,max=100'C crit_alarm=0'C. Unit:
        hwmon_coretemp]
...
```

v5: Fix asan issue in parse_hwmon_filename caught by a TMA metric.
v4: Drop merged patches 1 to 10. Separate adding the hwmon_pmu from
    the update to perf_pmu to use it. Try to make source of literal
    strings clearer via named #defines. Fix a number of GCC warnings.
v3: Rebase, add Namhyung's acked-by to patches 1 to 10.
v2: Address Namhyung's review feedback. Rebase dropping 4 patches
    applied by Arnaldo, fix build breakage reported by Arnaldo.

Ian Rogers (5):
  tools api io: Ensure line_len_out is always initialized
  perf hwmon_pmu: Add a tool PMU exposing events from hwmon in sysfs
  perf pmu: Add calls enabling the hwmon_pmu
  perf test: Add hwmon "PMU" test
  perf docs: Document tool and hwmon events

 tools/lib/api/io.h                     |   1 +
 tools/perf/Documentation/perf-list.txt |  15 +
 tools/perf/tests/Build                 |   1 +
 tools/perf/tests/builtin-test.c        |   1 +
 tools/perf/tests/hwmon_pmu.c           | 243 ++++++++
 tools/perf/tests/tests.h               |   1 +
 tools/perf/util/Build                  |   1 +
 tools/perf/util/evsel.c                |   9 +
 tools/perf/util/hwmon_pmu.c            | 820 +++++++++++++++++++++++++
 tools/perf/util/hwmon_pmu.h            | 154 +++++
 tools/perf/util/pmu.c                  |  20 +
 tools/perf/util/pmu.h                  |   2 +
 tools/perf/util/pmus.c                 |   9 +
 tools/perf/util/pmus.h                 |   3 +
 14 files changed, 1280 insertions(+)
 create mode 100644 tools/perf/tests/hwmon_pmu.c
 create mode 100644 tools/perf/util/hwmon_pmu.c
 create mode 100644 tools/perf/util/hwmon_pmu.h

-- 
2.47.0.105.g07ac214952-goog

[PATCH v5 1/5] tools api io: Ensure line_len_out is always initialized

[Ian Rogers]

Ensure initialization to avoid compiler warnings about potential use
of uninitialized variables.

Signed-off-by: Ian Rogers <irogers@google.com>
---
 tools/lib/api/io.h | 1 +
 1 file changed, 1 insertion(+)

diff --git a/tools/lib/api/io.h b/tools/lib/api/io.h
index d3eb04d1bc89..1731996b2c32 100644
--- a/tools/lib/api/io.h
+++ b/tools/lib/api/io.h
@@ -189,6 +189,7 @@ static inline ssize_t io__getdelim(struct io *io, char **line_out, size_t *line_
 err_out:
 	free(line);
 	*line_out = NULL;
+	*line_len_out = 0;
 	return -ENOMEM;
 }
 
-- 
2.47.0.105.g07ac214952-goog

[PATCH v5 2/5] perf hwmon_pmu: Add a tool PMU exposing events from hwmon in sysfs

[Ian Rogers]

Add a tool PMU for hwmon events but don't enable.

The hwmon sysfs ABI is defined in
Documentation/hwmon/sysfs-interface.rst. Create a PMU that reads the
hwmon input and can be used in `perf stat` and metrics much as an
uncore PMU can.

For example, when enabled by a later patch, the following shows
reading the CPU temperature and 2 fan speeds alongside the uncore
frequency:
```
$ perf stat -e temp_cpu,fan1,hwmon_thinkpad/fan2/,tool/num_cpus_online/ -M UNCORE_FREQ -I 1000
     1.001153138              52.00 'C   temp_cpu
     1.001153138              2,588 rpm  fan1
     1.001153138              2,482 rpm  hwmon_thinkpad/fan2/
     1.001153138                  8      tool/num_cpus_online/
     1.001153138      1,077,101,397      UNC_CLOCK.SOCKET                 #     1.08 UNCORE_FREQ
     1.001153138      1,012,773,595      duration_time
...
```

The PMUs are named from /sys/class/hwmon/hwmon<num>/name and have an
alias of hwmon<num>.

Hwmon data is presented in multiple <type><number>_<item> files. The
<type><number> is used to identify the event as is the <type> followed
by the contents of the <type>_label file if it exists. The
<type><number>_input file gives the data read by perf.

When enabled by a later patch, in `perf list` the other hwmon <item>
files are used to give a richer description, for example:
```
hwmon:
  temp1
       [Temperature in unit acpitz named temp1. Unit: hwmon_acpitz]
  in0
       [Voltage in unit bat0 named in0. Unit: hwmon_bat0]
  temp_core_0 OR temp2
       [Temperature in unit coretemp named Core 0. crit=100'C,max=100'C crit_alarm=0'C. Unit:
        hwmon_coretemp]
  temp_core_1 OR temp3
       [Temperature in unit coretemp named Core 1. crit=100'C,max=100'C crit_alarm=0'C. Unit:
        hwmon_coretemp]
...
  temp_package_id_0 OR temp1
       [Temperature in unit coretemp named Package id 0. crit=100'C,max=100'C crit_alarm=0'C.
        Unit: hwmon_coretemp]
  temp1
       [Temperature in unit iwlwifi_1 named temp1. Unit: hwmon_iwlwifi_1]
  temp_composite OR temp1
       [Temperature in unit nvme named Composite. alarm=0'C,crit=86.85'C,max=75.85'C,
        min=-273.15'C. Unit: hwmon_nvme]
  temp_sensor_1 OR temp2
       [Temperature in unit nvme named Sensor 1. max=65261.8'C,min=-273.15'C. Unit: hwmon_nvme]
  temp_sensor_2 OR temp3
       [Temperature in unit nvme named Sensor 2. max=65261.8'C,min=-273.15'C. Unit: hwmon_nvme]
  fan1
       [Fan in unit thinkpad named fan1. Unit: hwmon_thinkpad]
  fan2
       [Fan in unit thinkpad named fan2. Unit: hwmon_thinkpad]
...
  temp_cpu OR temp1
       [Temperature in unit thinkpad named CPU. Unit: hwmon_thinkpad]
  temp_gpu OR temp2
       [Temperature in unit thinkpad named GPU. Unit: hwmon_thinkpad]
  curr1
       [Current in unit ucsi_source_psy_usbc000_0 named curr1. max=1.5A. Unit:
        hwmon_ucsi_source_psy_usbc000_0]
  in0
       [Voltage in unit ucsi_source_psy_usbc000_0 named in0. max=5V,min=5V. Unit:
        hwmon_ucsi_source_psy_usbc000_0]
```

As there may be multiple hwmon devices a range of PMU types are
reserved for their use and to identify the PMU as belonging to the
hwmon types.

Signed-off-by: Ian Rogers <irogers@google.com>
---
 tools/perf/util/Build       |   1 +
 tools/perf/util/hwmon_pmu.c | 820 ++++++++++++++++++++++++++++++++++++
 tools/perf/util/hwmon_pmu.h | 154 +++++++
 tools/perf/util/pmu.h       |   2 +
 4 files changed, 977 insertions(+)
 create mode 100644 tools/perf/util/hwmon_pmu.c
 create mode 100644 tools/perf/util/hwmon_pmu.h

diff --git a/tools/perf/util/Build b/tools/perf/util/Build
index fa508e113dd0..9eb8b1c3df94 100644
--- a/tools/perf/util/Build
+++ b/tools/perf/util/Build
@@ -83,6 +83,7 @@ perf-util-y += pmu.o
 perf-util-y += pmus.o
 perf-util-y += pmu-flex.o
 perf-util-y += pmu-bison.o
+perf-util-y += hwmon_pmu.o
 perf-util-y += tool_pmu.o
 perf-util-y += svghelper.o
 perf-util-$(CONFIG_LIBTRACEEVENT) += trace-event-info.o
diff --git a/tools/perf/util/hwmon_pmu.c b/tools/perf/util/hwmon_pmu.c
new file mode 100644
index 000000000000..2ef08940a12c
--- /dev/null
+++ b/tools/perf/util/hwmon_pmu.c
@@ -0,0 +1,820 @@
+// SPDX-License-Identifier: (LGPL-2.1 OR BSD-2-Clause)
+#include "counts.h"
+#include "debug.h"
+#include "evsel.h"
+#include "hashmap.h"
+#include "hwmon_pmu.h"
+#include "pmu.h"
+#include <internal/xyarray.h>
+#include <internal/threadmap.h>
+#include <perf/threadmap.h>
+#include <sys/types.h>
+#include <ctype.h>
+#include <dirent.h>
+#include <fcntl.h>
+#include <api/fs/fs.h>
+#include <api/io.h>
+#include <linux/zalloc.h>
+
+const char * const hwmon_type_strs[HWMON_TYPE_MAX] = {
+	NULL,
+	"cpu",
+	"curr",
+	"energy",
+	"fan",
+	"humidity",
+	"in",
+	"intrusion",
+	"power",
+	"pwm",
+	"temp",
+};
+#define LONGEST_HWMON_TYPE_STR "intrusion"
+
+static const char *const hwmon_units[HWMON_TYPE_MAX] = {
+	NULL,
+	"V",   /* cpu */
+	"A",   /* curr */
+	"J",   /* energy */
+	"rpm", /* fan */
+	"%",   /* humidity */
+	"V",   /* in */
+	"",    /* intrusion */
+	"W",   /* power */
+	"Hz",  /* pwm */
+	"'C",  /* temp */
+};
+
+const char * const hwmon_item_strs[HWMON_ITEM__MAX] = {
+	NULL,
+	"accuracy",
+	"alarm",
+	"auto_channels_temp",
+	"average",
+	"average_highest",
+	"average_interval",
+	"average_interval_max",
+	"average_interval_min",
+	"average_lowest",
+	"average_max",
+	"average_min",
+	"beep",
+	"cap",
+	"cap_hyst",
+	"cap_max",
+	"cap_min",
+	"crit",
+	"crit_hyst",
+	"div",
+	"emergency",
+	"emergency_hist",
+	"enable",
+	"fault",
+	"freq",
+	"highest",
+	"input",
+	"label",
+	"lcrit",
+	"lcrit_hyst",
+	"lowest",
+	"max",
+	"max_hyst",
+	"min",
+	"min_hyst",
+	"mod",
+	"offset",
+	"pulses",
+	"rated_max",
+	"rated_min",
+	"reset_history",
+	"target",
+	"type",
+	"vid",
+};
+#define LONGEST_HWMON_ITEM_STR "average_interval_max"
+
+struct hwmon_pmu {
+	struct perf_pmu pmu;
+	struct hashmap events;
+	int hwmon_dir_fd;
+};
+
+/**
+ * union hwmon_pmu_event_key: Key for hwmon_pmu->events as such each key
+ * represents an event.
+ *
+ * Related hwmon files start <type><number> that this key represents.
+ */
+union hwmon_pmu_event_key {
+	long type_and_num;
+	struct {
+		int num :16;
+		enum hwmon_type type :8;
+	};
+};
+
+/**
+ * struct hwmon_pmu_event_value: Value in hwmon_pmu->events.
+ *
+ * Hwmon files are of the form <type><number>_<item> and may have a suffix
+ * _alarm.
+ */
+struct hwmon_pmu_event_value {
+	/** @items: which item files are present. */
+	DECLARE_BITMAP(items, HWMON_ITEM__MAX);
+	/** @alarm_items: which item files are present. */
+	DECLARE_BITMAP(alarm_items, HWMON_ITEM__MAX);
+	/** @label: contents of <type><number>_label if present. */
+	char *label;
+	/** @name: name computed from label of the form <type>_<label>. */
+	char *name;
+};
+
+bool perf_pmu__is_hwmon(const struct perf_pmu *pmu)
+{
+	return pmu && pmu->type >= PERF_PMU_TYPE_HWMON_START &&
+		pmu->type <= PERF_PMU_TYPE_HWMON_END;
+}
+
+bool evsel__is_hwmon(const struct evsel *evsel)
+{
+	return perf_pmu__is_hwmon(evsel->pmu);
+}
+
+static size_t hwmon_pmu__event_hashmap_hash(long key, void *ctx __maybe_unused)
+{
+	return ((union hwmon_pmu_event_key)key).type_and_num;
+}
+
+static bool hwmon_pmu__event_hashmap_equal(long key1, long key2, void *ctx __maybe_unused)
+{
+	return ((union hwmon_pmu_event_key)key1).type_and_num ==
+	       ((union hwmon_pmu_event_key)key2).type_and_num;
+}
+
+static int hwmon_strcmp(const void *a, const void *b)
+{
+	const char *sa = a;
+	const char * const *sb = b;
+
+	return strcmp(sa, *sb);
+}
+
+bool parse_hwmon_filename(const char *filename,
+			  enum hwmon_type *type,
+			  int *number,
+			  enum hwmon_item *item,
+			  bool *alarm)
+{
+	char fn_type[24];
+	const char **elem;
+	const char *fn_item = NULL;
+	size_t fn_item_len;
+
+	assert(strlen(LONGEST_HWMON_TYPE_STR) < sizeof(fn_type));
+	strlcpy(fn_type, filename, sizeof(fn_type));
+	for (size_t i = 0; fn_type[i] != '\0'; i++) {
+		if (fn_type[i] >= '0' && fn_type[i] <= '9') {
+			fn_type[i] = '\0';
+			*number = strtoul(&filename[i], (char **)&fn_item, 10);
+			if (*fn_item == '_')
+				fn_item++;
+			break;
+		}
+		if (fn_type[i] == '_') {
+			fn_type[i] = '\0';
+			*number = -1;
+			fn_item = &filename[i + 1];
+			break;
+		}
+	}
+	if (fn_item == NULL || fn_type[0] == '\0' || (item != NULL && fn_item[0] == '\0')) {
+		pr_debug("hwmon_pmu: not a hwmon file '%s'\n", filename);
+		return false;
+	}
+	elem = bsearch(&fn_type, hwmon_type_strs + 1, ARRAY_SIZE(hwmon_type_strs) - 1,
+		       sizeof(hwmon_type_strs[0]), hwmon_strcmp);
+	if (!elem) {
+		pr_debug("hwmon_pmu: not a hwmon type '%s' in file name '%s'\n",
+			 fn_type, filename);
+		return false;
+	}
+
+	*type = elem - &hwmon_type_strs[0];
+	if (!item)
+		return true;
+
+	*alarm = false;
+	fn_item_len = strlen(fn_item);
+	if (fn_item_len > 6 && !strcmp(&fn_item[fn_item_len - 6], "_alarm")) {
+		assert(strlen(LONGEST_HWMON_ITEM_STR) < sizeof(fn_type));
+		strlcpy(fn_type, fn_item, fn_item_len - 6);
+		fn_item = fn_type;
+		*alarm = true;
+	}
+	elem = bsearch(fn_item, hwmon_item_strs + 1, ARRAY_SIZE(hwmon_item_strs) - 1,
+		       sizeof(hwmon_item_strs[0]), hwmon_strcmp);
+	if (!elem) {
+		pr_debug("hwmon_pmu: not a hwmon item '%s' in file name '%s'\n",
+			 fn_item, filename);
+		return false;
+	}
+	*item = elem - &hwmon_item_strs[0];
+	return true;
+}
+
+static void fix_name(char *p)
+{
+	char *s = strchr(p, '\n');
+
+	if (s)
+		*s = '\0';
+
+	while (*p != '\0') {
+		if (strchr(" :,/\n\t", *p))
+			*p = '_';
+		else
+			*p = tolower(*p);
+		p++;
+	}
+}
+
+static int hwmon_pmu__read_events(struct hwmon_pmu *pmu)
+{
+	DIR *dir;
+	struct dirent *ent;
+	int dup_fd, err = 0;
+	struct hashmap_entry *cur, *tmp;
+	size_t bkt;
+
+	if (pmu->pmu.sysfs_aliases_loaded)
+		return 0;
+
+	/* Use a dup-ed fd as closedir will close it. */
+	dup_fd = dup(pmu->hwmon_dir_fd);
+	if (dup_fd == -1)
+		return -ENOMEM;
+
+	dir = fdopendir(dup_fd);
+	if (!dir) {
+		close(dup_fd);
+		return -ENOMEM;
+	}
+
+	while ((ent = readdir(dir)) != NULL) {
+		enum hwmon_type type;
+		int number;
+		enum hwmon_item item;
+		bool alarm;
+		union hwmon_pmu_event_key key = {};
+		struct hwmon_pmu_event_value *value;
+
+		if (ent->d_type != DT_REG)
+			continue;
+
+		if (!parse_hwmon_filename(ent->d_name, &type, &number, &item, &alarm)) {
+			pr_debug("Not a hwmon file '%s'\n", ent->d_name);
+			continue;
+		}
+		key.num = number;
+		key.type = type;
+		if (!hashmap__find(&pmu->events, key.type_and_num, &value)) {
+			value = zalloc(sizeof(*value));
+			if (!value) {
+				err = -ENOMEM;
+				goto err_out;
+			}
+			err = hashmap__add(&pmu->events, key.type_and_num, value);
+			if (err) {
+				free(value);
+				err = -ENOMEM;
+				goto err_out;
+			}
+		}
+		__set_bit(item, alarm ? value->alarm_items : value->items);
+		if (item == HWMON_ITEM_LABEL) {
+			char buf[128];
+			int fd = openat(pmu->hwmon_dir_fd, ent->d_name, O_RDONLY);
+			ssize_t read_len;
+
+			if (fd < 0)
+				continue;
+
+			read_len = read(fd, buf, sizeof(buf));
+
+			while (read_len > 0 && buf[read_len - 1] == '\n')
+				read_len--;
+
+			if (read_len > 0)
+				buf[read_len] = '\0';
+
+			if (buf[0] == '\0') {
+				pr_debug("hwmon_pmu: empty label file %s %s\n",
+					 pmu->pmu.name, ent->d_name);
+				close(fd);
+				continue;
+			}
+			value->label = strdup(buf);
+			if (!value->label) {
+				pr_debug("hwmon_pmu: memory allocation failure\n");
+				close(fd);
+				continue;
+			}
+			snprintf(buf, sizeof(buf), "%s_%s", hwmon_type_strs[type], value->label);
+			fix_name(buf);
+			value->name = strdup(buf);
+			if (!value->name)
+				pr_debug("hwmon_pmu: memory allocation failure\n");
+			close(fd);
+		}
+	}
+	hashmap__for_each_entry_safe((&pmu->events), cur, tmp, bkt) {
+		union hwmon_pmu_event_key key = {
+			.type_and_num = cur->key,
+		};
+		struct hwmon_pmu_event_value *value = cur->pvalue;
+
+		if (!test_bit(HWMON_ITEM_INPUT, value->items)) {
+			pr_debug("hwmon_pmu: removing event '%s%d' that has no input file\n",
+				hwmon_type_strs[key.type], key.num);
+			hashmap__delete(&pmu->events, key.type_and_num, &key, &value);
+			zfree(&value->label);
+			zfree(&value->name);
+			free(value);
+		}
+	}
+	pmu->pmu.sysfs_aliases_loaded = true;
+
+err_out:
+	closedir(dir);
+	return err;
+}
+
+struct perf_pmu *hwmon_pmu__new(struct list_head *pmus, int hwmon_dir, const char *sysfs_name, const char *name)
+{
+	char buf[32];
+	struct hwmon_pmu *hwm;
+
+	hwm = zalloc(sizeof(*hwm));
+	if (!hwm)
+		return NULL;
+
+
+	hwm->hwmon_dir_fd = hwmon_dir;
+	hwm->pmu.type = PERF_PMU_TYPE_HWMON_START + strtoul(sysfs_name + 5, NULL, 10);
+	if (hwm->pmu.type > PERF_PMU_TYPE_HWMON_END) {
+		pr_err("Unable to encode hwmon type from %s in valid PMU type\n", sysfs_name);
+		goto err_out;
+	}
+	snprintf(buf, sizeof(buf), "hwmon_%s", name);
+	fix_name(buf + 6);
+	hwm->pmu.name = strdup(buf);
+	if (!hwm->pmu.name)
+		goto err_out;
+	hwm->pmu.alias_name = strdup(sysfs_name);
+	if (!hwm->pmu.alias_name)
+		goto err_out;
+	hwm->pmu.cpus = perf_cpu_map__new("0");
+	if (!hwm->pmu.cpus)
+		goto err_out;
+	INIT_LIST_HEAD(&hwm->pmu.format);
+	INIT_LIST_HEAD(&hwm->pmu.aliases);
+	INIT_LIST_HEAD(&hwm->pmu.caps);
+	hashmap__init(&hwm->events, hwmon_pmu__event_hashmap_hash,
+		      hwmon_pmu__event_hashmap_equal, /*ctx=*/NULL);
+
+	list_add_tail(&hwm->pmu.list, pmus);
+	return &hwm->pmu;
+err_out:
+	free((char *)hwm->pmu.name);
+	free(hwm->pmu.alias_name);
+	free(hwm);
+	close(hwmon_dir);
+	return NULL;
+}
+
+void hwmon_pmu__exit(struct perf_pmu *pmu)
+{
+	struct hwmon_pmu *hwm = container_of(pmu, struct hwmon_pmu, pmu);
+	struct hashmap_entry *cur, *tmp;
+	size_t bkt;
+
+	hashmap__for_each_entry_safe((&hwm->events), cur, tmp, bkt) {
+		struct hwmon_pmu_event_value *value = cur->pvalue;
+
+		zfree(&value->label);
+		zfree(&value->name);
+		free(value);
+	}
+	hashmap__clear(&hwm->events);
+	close(hwm->hwmon_dir_fd);
+}
+
+static size_t hwmon_pmu__describe_items(struct hwmon_pmu *hwm, char *out_buf, size_t out_buf_len,
+					union hwmon_pmu_event_key key,
+					const unsigned long *items, bool is_alarm)
+{
+	size_t bit;
+	char buf[64];
+	size_t len = 0;
+
+	for_each_set_bit(bit, items, HWMON_ITEM__MAX) {
+		int fd;
+
+		if (bit == HWMON_ITEM_LABEL || bit == HWMON_ITEM_INPUT)
+			continue;
+
+		snprintf(buf, sizeof(buf), "%s%d_%s%s",
+			hwmon_type_strs[key.type],
+			key.num,
+			hwmon_item_strs[bit],
+			is_alarm ? "_alarm" : "");
+		fd = openat(hwm->hwmon_dir_fd, buf, O_RDONLY);
+		if (fd > 0) {
+			ssize_t read_len = read(fd, buf, sizeof(buf));
+
+			while (read_len > 0 && buf[read_len - 1] == '\n')
+				read_len--;
+
+			if (read_len > 0) {
+				long long val;
+
+				buf[read_len] = '\0';
+				val = strtoll(buf, /*endptr=*/NULL, 10);
+				len += snprintf(out_buf + len, out_buf_len - len, "%s%s%s=%g%s",
+						len == 0 ? " " : ", ",
+						hwmon_item_strs[bit],
+						is_alarm ? "_alarm" : "",
+						(double)val / 1000.0,
+						hwmon_units[key.type]);
+			}
+			close(fd);
+		}
+	}
+	return len;
+}
+
+int hwmon_pmu__for_each_event(struct perf_pmu *pmu, void *state, pmu_event_callback cb)
+{
+	struct hwmon_pmu *hwm = container_of(pmu, struct hwmon_pmu, pmu);
+	struct hashmap_entry *cur;
+	size_t bkt;
+
+	if (hwmon_pmu__read_events(hwm))
+		return false;
+
+	hashmap__for_each_entry((&hwm->events), cur, bkt) {
+		static const char *const hwmon_scale_units[HWMON_TYPE_MAX] = {
+			NULL,
+			"0.001V", /* cpu */
+			"0.001A", /* curr */
+			"0.001J", /* energy */
+			"1rpm",   /* fan */
+			"0.001%", /* humidity */
+			"0.001V", /* in */
+			NULL,     /* intrusion */
+			"0.001W", /* power */
+			"1Hz",    /* pwm */
+			"0.001'C", /* temp */
+		};
+		static const char *const hwmon_desc[HWMON_TYPE_MAX] = {
+			NULL,
+			"CPU core reference voltage",   /* cpu */
+			"Current",                      /* curr */
+			"Cumulative energy use",        /* energy */
+			"Fan",                          /* fan */
+			"Humidity",                     /* humidity */
+			"Voltage",                      /* in */
+			"Chassis intrusion detection",  /* intrusion */
+			"Power use",                    /* power */
+			"Pulse width modulation fan control", /* pwm */
+			"Temperature",                  /* temp */
+		};
+		char alias_buf[64];
+		char desc_buf[256];
+		char encoding_buf[128];
+		union hwmon_pmu_event_key key = {
+			.type_and_num = cur->key,
+		};
+		struct hwmon_pmu_event_value *value = cur->pvalue;
+		struct pmu_event_info info = {
+			.pmu = pmu,
+			.name = value->name,
+			.alias = alias_buf,
+			.scale_unit = hwmon_scale_units[key.type],
+			.desc = desc_buf,
+			.long_desc = NULL,
+			.encoding_desc = encoding_buf,
+			.topic = "hwmon",
+			.pmu_name = pmu->name,
+			.event_type_desc = "Hwmon event",
+		};
+		int ret;
+		size_t len;
+
+		len = snprintf(alias_buf, sizeof(alias_buf), "%s%d",
+			       hwmon_type_strs[key.type], key.num);
+		if (!info.name) {
+			info.name = info.alias;
+			info.alias = NULL;
+		}
+
+		len = snprintf(desc_buf, sizeof(desc_buf), "%s in unit %s named %s.",
+			hwmon_desc[key.type],
+			pmu->name + 6,
+			value->label ?: info.name);
+
+		len += hwmon_pmu__describe_items(hwm, desc_buf + len, sizeof(desc_buf) - len,
+						key, value->items, /*is_alarm=*/false);
+
+		len += hwmon_pmu__describe_items(hwm, desc_buf + len, sizeof(desc_buf) - len,
+						key, value->alarm_items, /*is_alarm=*/true);
+
+		snprintf(encoding_buf, sizeof(encoding_buf), "%s/config=0x%lx/",
+			 pmu->name, cur->key);
+
+		ret = cb(state, &info);
+		if (ret)
+			return ret;
+	}
+	return 0;
+}
+
+size_t hwmon_pmu__num_events(struct perf_pmu *pmu)
+{
+	struct hwmon_pmu *hwm = container_of(pmu, struct hwmon_pmu, pmu);
+
+	hwmon_pmu__read_events(hwm);
+	return hashmap__size(&hwm->events);
+}
+
+bool hwmon_pmu__have_event(struct perf_pmu *pmu, const char *name)
+{
+	struct hwmon_pmu *hwm = container_of(pmu, struct hwmon_pmu, pmu);
+	enum hwmon_type type;
+	int number;
+	union hwmon_pmu_event_key key = {};
+	struct hashmap_entry *cur;
+	size_t bkt;
+
+	if (!parse_hwmon_filename(name, &type, &number, /*item=*/NULL, /*is_alarm=*/NULL))
+		return false;
+
+	if (hwmon_pmu__read_events(hwm))
+		return false;
+
+	key.type = type;
+	key.num = number;
+	if (hashmap_find(&hwm->events, key.type_and_num, /*value=*/NULL))
+		return true;
+	if (key.num != -1)
+		return false;
+	/* Item is of form <type>_ which means we should match <type>_<label>. */
+	hashmap__for_each_entry((&hwm->events), cur, bkt) {
+		struct hwmon_pmu_event_value *value = cur->pvalue;
+
+		key.type_and_num = cur->key;
+		if (key.type == type && value->name && !strcasecmp(name, value->name))
+			return true;
+	}
+	return false;
+}
+
+static int hwmon_pmu__config_term(const struct hwmon_pmu *hwm,
+				  struct perf_event_attr *attr,
+				  struct parse_events_term *term,
+				  struct parse_events_error *err)
+{
+	if (term->type_term == PARSE_EVENTS__TERM_TYPE_USER) {
+		enum hwmon_type type;
+		int number;
+
+		if (parse_hwmon_filename(term->config, &type, &number,
+					 /*item=*/NULL, /*is_alarm=*/NULL)) {
+			if (number == -1) {
+				/*
+				 * Item is of form <type>_ which means we should
+				 * match <type>_<label>.
+				 */
+				struct hashmap_entry *cur;
+				size_t bkt;
+
+				attr->config = 0;
+				hashmap__for_each_entry((&hwm->events), cur, bkt) {
+					union hwmon_pmu_event_key key = {
+						.type_and_num = cur->key,
+					};
+					struct hwmon_pmu_event_value *value = cur->pvalue;
+
+					if (key.type == type && value->name &&
+					    !strcasecmp(term->config, value->name)) {
+						attr->config = key.type_and_num;
+						break;
+					}
+				}
+				if (attr->config == 0)
+					return -EINVAL;
+			} else {
+				union hwmon_pmu_event_key key = {
+					.type = type,
+					.num = number,
+				};
+
+				attr->config = key.type_and_num;
+			}
+			return 0;
+		}
+	}
+	if (err) {
+		char *err_str;
+
+		parse_events_error__handle(err, term->err_val,
+					asprintf(&err_str,
+						"unexpected hwmon event term (%s) %s",
+						parse_events__term_type_str(term->type_term),
+						term->config) < 0
+					? strdup("unexpected hwmon event term")
+					: err_str,
+					NULL);
+	}
+	return -EINVAL;
+}
+
+int hwmon_pmu__config_terms(const struct perf_pmu *pmu,
+			    struct perf_event_attr *attr,
+			    struct parse_events_terms *terms,
+			    struct parse_events_error *err)
+{
+	const struct hwmon_pmu *hwm = container_of(pmu, struct hwmon_pmu, pmu);
+	struct parse_events_term *term;
+
+	assert(pmu->sysfs_aliases_loaded);
+	list_for_each_entry(term, &terms->terms, list) {
+		if (hwmon_pmu__config_term(hwm, attr, term, err))
+			return -EINVAL;
+	}
+
+	return 0;
+
+}
+
+int hwmon_pmu__check_alias(struct parse_events_terms *terms, struct perf_pmu_info *info,
+			   struct parse_events_error *err)
+{
+	struct parse_events_term *term =
+		list_first_entry(&terms->terms, struct parse_events_term, list);
+
+	if (term->type_term == PARSE_EVENTS__TERM_TYPE_USER) {
+		enum hwmon_type type;
+		int number;
+
+		if (parse_hwmon_filename(term->config, &type, &number,
+					 /*item=*/NULL, /*is_alarm=*/NULL)) {
+			info->unit = hwmon_units[type];
+			if (type == HWMON_TYPE_FAN || type == HWMON_TYPE_PWM ||
+			    type == HWMON_TYPE_INTRUSION)
+				info->scale = 1;
+			else
+				info->scale = 0.001;
+		}
+		return 0;
+	}
+	if (err) {
+		char *err_str;
+
+		parse_events_error__handle(err, term->err_val,
+					asprintf(&err_str,
+						"unexpected hwmon event term (%s) %s",
+						parse_events__term_type_str(term->type_term),
+						term->config) < 0
+					? strdup("unexpected hwmon event term")
+					: err_str,
+					NULL);
+	}
+	return -EINVAL;
+}
+
+int perf_pmus__read_hwmon_pmus(struct list_head *pmus)
+{
+	char *line = NULL;
+	DIR *class_hwmon_dir;
+	struct dirent *class_hwmon_ent;
+	char buf[PATH_MAX];
+	const char *sysfs = sysfs__mountpoint();
+
+	if (!sysfs)
+		return 0;
+
+	scnprintf(buf, sizeof(buf), "%s/class/hwmon/", sysfs);
+	class_hwmon_dir = opendir(buf);
+	if (!class_hwmon_dir)
+		return 0;
+
+	while ((class_hwmon_ent = readdir(class_hwmon_dir)) != NULL) {
+		size_t line_len;
+		int hwmon_dir, name_fd;
+		struct io io;
+
+		if (class_hwmon_ent->d_type != DT_LNK)
+			continue;
+
+		scnprintf(buf, sizeof(buf), "%s/class/hwmon/%s", sysfs, class_hwmon_ent->d_name);
+		hwmon_dir = open(buf, O_DIRECTORY);
+		if (hwmon_dir == -1) {
+			pr_debug("hwmon_pmu: not a directory: '%s/class/hwmon/%s'\n",
+				 sysfs, class_hwmon_ent->d_name);
+			continue;
+		}
+		name_fd = openat(hwmon_dir, "name", O_RDONLY);
+		if (name_fd == -1) {
+			pr_debug("hwmon_pmu: failure to open '%s/class/hwmon/%s/name'\n",
+				  sysfs, class_hwmon_ent->d_name);
+			close(hwmon_dir);
+			continue;
+		}
+		io__init(&io, name_fd, buf, sizeof(buf));
+		io__getline(&io, &line, &line_len);
+		if (line_len > 0 && line[line_len - 1] == '\n')
+			line[line_len - 1] = '\0';
+		hwmon_pmu__new(pmus, hwmon_dir, class_hwmon_ent->d_name, line);
+		close(name_fd);
+	}
+	free(line);
+	closedir(class_hwmon_dir);
+	return 0;
+}
+
+#define FD(e, x, y) (*(int *)xyarray__entry(e->core.fd, x, y))
+
+int evsel__hwmon_pmu_open(struct evsel *evsel,
+			  struct perf_thread_map *threads,
+			  int start_cpu_map_idx, int end_cpu_map_idx)
+{
+	struct hwmon_pmu *hwm = container_of(evsel->pmu, struct hwmon_pmu, pmu);
+	union hwmon_pmu_event_key key = {
+		.type_and_num = evsel->core.attr.config,
+	};
+	int idx = 0, thread = 0, nthreads, err = 0;
+
+	nthreads = perf_thread_map__nr(threads);
+	for (idx = start_cpu_map_idx; idx < end_cpu_map_idx; idx++) {
+		for (thread = 0; thread < nthreads; thread++) {
+			char buf[64];
+			int fd;
+
+			snprintf(buf, sizeof(buf), "%s%d_input",
+				 hwmon_type_strs[key.type], key.num);
+
+			fd = openat(hwm->hwmon_dir_fd, buf, O_RDONLY);
+			FD(evsel, idx, thread) = fd;
+			if (fd < 0) {
+				err = -errno;
+				goto out_close;
+			}
+		}
+	}
+	return 0;
+out_close:
+	if (err)
+		threads->err_thread = thread;
+
+	do {
+		while (--thread >= 0) {
+			if (FD(evsel, idx, thread) >= 0)
+				close(FD(evsel, idx, thread));
+			FD(evsel, idx, thread) = -1;
+		}
+		thread = nthreads;
+	} while (--idx >= 0);
+	return err;
+}
+
+int evsel__hwmon_pmu_read(struct evsel *evsel, int cpu_map_idx, int thread)
+{
+	char buf[32];
+	int fd;
+	ssize_t len;
+	struct perf_counts_values *count, *old_count = NULL;
+
+	if (evsel->prev_raw_counts)
+		old_count = perf_counts(evsel->prev_raw_counts, cpu_map_idx, thread);
+
+	count = perf_counts(evsel->counts, cpu_map_idx, thread);
+	fd = FD(evsel, cpu_map_idx, thread);
+	len = pread(fd, buf, sizeof(buf), 0);
+	if (len <= 0) {
+		count->lost++;
+		return -EINVAL;
+	}
+	buf[len] = '\0';
+	if (old_count) {
+		count->val = old_count->val + strtoll(buf, NULL, 10);
+		count->run = old_count->run + 1;
+		count->ena = old_count->ena + 1;
+	} else {
+		count->val = strtoll(buf, NULL, 10);
+		count->run++;
+		count->ena++;
+	}
+	return 0;
+}
diff --git a/tools/perf/util/hwmon_pmu.h b/tools/perf/util/hwmon_pmu.h
new file mode 100644
index 000000000000..8061301fcd8e
--- /dev/null
+++ b/tools/perf/util/hwmon_pmu.h
@@ -0,0 +1,154 @@
+/* SPDX-License-Identifier: (LGPL-2.1 OR BSD-2-Clause) */
+#ifndef __HWMON_PMU_H
+#define __HWMON_PMU_H
+
+#include "pmu.h"
+
+struct list_head;
+
+/**
+ * enum hwmon_type:
+ *
+ * As described in Documentation/hwmon/sysfs-interface.rst hwmon events are
+ * defined over multiple files of the form <type><num>_<item>. This enum
+ * captures potential <type> values.
+ *
+ * This enum is exposed for testing.
+ */
+enum hwmon_type {
+	HWMON_TYPE_NONE,
+
+	HWMON_TYPE_CPU,
+	HWMON_TYPE_CURR,
+	HWMON_TYPE_ENERGY,
+	HWMON_TYPE_FAN,
+	HWMON_TYPE_HUMIDITY,
+	HWMON_TYPE_IN,
+	HWMON_TYPE_INTRUSION,
+	HWMON_TYPE_POWER,
+	HWMON_TYPE_PWM,
+	HWMON_TYPE_TEMP,
+
+	HWMON_TYPE_MAX
+};
+
+/**
+ * enum hwmon_item:
+ *
+ * Similar to enum hwmon_type but describes the item part of a a sysfs filename.
+ *
+ * This enum is exposed for testing.
+ */
+enum hwmon_item {
+	HWMON_ITEM_NONE,
+
+	HWMON_ITEM_ACCURACY,
+	HWMON_ITEM_ALARM,
+	HWMON_ITEM_AUTO_CHANNELS_TEMP,
+	HWMON_ITEM_AVERAGE,
+	HWMON_ITEM_AVERAGE_HIGHEST,
+	HWMON_ITEM_AVERAGE_INTERVAL,
+	HWMON_ITEM_AVERAGE_INTERVAL_MAX,
+	HWMON_ITEM_AVERAGE_INTERVAL_MIN,
+	HWMON_ITEM_AVERAGE_LOWEST,
+	HWMON_ITEM_AVERAGE_MAX,
+	HWMON_ITEM_AVERAGE_MIN,
+	HWMON_ITEM_BEEP,
+	HWMON_ITEM_CAP,
+	HWMON_ITEM_CAP_HYST,
+	HWMON_ITEM_CAP_MAX,
+	HWMON_ITEM_CAP_MIN,
+	HWMON_ITEM_CRIT,
+	HWMON_ITEM_CRIT_HYST,
+	HWMON_ITEM_DIV,
+	HWMON_ITEM_EMERGENCY,
+	HWMON_ITEM_EMERGENCY_HIST,
+	HWMON_ITEM_ENABLE,
+	HWMON_ITEM_FAULT,
+	HWMON_ITEM_FREQ,
+	HWMON_ITEM_HIGHEST,
+	HWMON_ITEM_INPUT,
+	HWMON_ITEM_LABEL,
+	HWMON_ITEM_LCRIT,
+	HWMON_ITEM_LCRIT_HYST,
+	HWMON_ITEM_LOWEST,
+	HWMON_ITEM_MAX,
+	HWMON_ITEM_MAX_HYST,
+	HWMON_ITEM_MIN,
+	HWMON_ITEM_MIN_HYST,
+	HWMON_ITEM_MOD,
+	HWMON_ITEM_OFFSET,
+	HWMON_ITEM_PULSES,
+	HWMON_ITEM_RATED_MAX,
+	HWMON_ITEM_RATED_MIN,
+	HWMON_ITEM_RESET_HISTORY,
+	HWMON_ITEM_TARGET,
+	HWMON_ITEM_TYPE,
+	HWMON_ITEM_VID,
+
+	HWMON_ITEM__MAX,
+};
+
+/** Strings that correspond to enum hwmon_type. */
+extern const char * const hwmon_type_strs[HWMON_TYPE_MAX];
+/** Strings that correspond to enum hwmon_item. */
+extern const char * const hwmon_item_strs[HWMON_ITEM__MAX];
+
+bool perf_pmu__is_hwmon(const struct perf_pmu *pmu);
+bool evsel__is_hwmon(const struct evsel *evsel);
+
+/**
+ * parse_hwmon_filename() - Parse filename into constituent parts.
+ *
+ * @filename: To be parsed, of the form <type><number>_<item>.
+ * @type: The type defined from the parsed file name.
+ * @number: The number of the type, for example there may be more than 1 fan.
+ * @item: A hwmon <type><number> may have multiple associated items.
+ * @alarm: Is the filename for an alarm value?
+ *
+ * An example of a hwmon filename is "temp1_input". The type is temp for a
+ * temperature value. The number is 1. The item within the file is an input
+ * value - the temperature itself. This file doesn't contain an alarm value.
+ *
+ * Exposed for testing.
+ */
+bool parse_hwmon_filename(const char *filename,
+			  enum hwmon_type *type,
+			  int *number,
+			  enum hwmon_item *item,
+			  bool *alarm);
+
+/**
+ * hwmon_pmu__new() - Allocate and construct a hwmon PMU.
+ *
+ * @pmus: The list of PMUs to be added to.
+ * @hwmon_dir: An O_DIRECTORY file descriptor for a hwmon directory.
+ * @sysfs_name: Name of the hwmon sysfs directory like hwmon0.
+ * @name: The contents of the "name" file in the hwmon directory.
+ *
+ * Exposed for testing. Regular construction should happen via
+ * perf_pmus__read_hwmon_pmus.
+ */
+struct perf_pmu *hwmon_pmu__new(struct list_head *pmus, int hwmon_dir,
+				const char *sysfs_name, const char *name);
+void hwmon_pmu__exit(struct perf_pmu *pmu);
+
+int hwmon_pmu__for_each_event(struct perf_pmu *pmu, void *state, pmu_event_callback cb);
+size_t hwmon_pmu__num_events(struct perf_pmu *pmu);
+bool hwmon_pmu__have_event(struct perf_pmu *pmu, const char *name);
+int hwmon_pmu__config_terms(const struct perf_pmu *pmu,
+			    struct perf_event_attr *attr,
+			    struct parse_events_terms *terms,
+			    struct parse_events_error *err);
+int hwmon_pmu__check_alias(struct parse_events_terms *terms, struct perf_pmu_info *info,
+			   struct parse_events_error *err);
+
+int perf_pmus__read_hwmon_pmus(struct list_head *pmus);
+
+
+int evsel__hwmon_pmu_open(struct evsel *evsel,
+			 struct perf_thread_map *threads,
+			 int start_cpu_map_idx, int end_cpu_map_idx);
+int evsel__hwmon_pmu_read(struct evsel *evsel, int cpu_map_idx, int thread);
+
+#endif /* __HWMON_PMU_H */
diff --git a/tools/perf/util/pmu.h b/tools/perf/util/pmu.h
index e400db9e9eb1..10f23f48479b 100644
--- a/tools/perf/util/pmu.h
+++ b/tools/perf/util/pmu.h
@@ -37,6 +37,8 @@ struct perf_pmu_caps {
 };
 
 enum {
+	PERF_PMU_TYPE_HWMON_START = 0xFFFF0000,
+	PERF_PMU_TYPE_HWMON_END   = 0xFFFFFFFD,
 	PERF_PMU_TYPE_TOOL = 0xFFFFFFFE,
 	PERF_PMU_TYPE_FAKE = 0xFFFFFFFF,
 };
-- 
2.47.0.105.g07ac214952-goog

[PATCH v5 3/5] perf pmu: Add calls enabling the hwmon_pmu

[Ian Rogers]

Add the base PMU calls necessary for hwmon_pmu(s) to be
created/deleted and events found, listed, opened and read.

Signed-off-by: Ian Rogers <irogers@google.com>
---
 tools/perf/util/evsel.c |  9 +++++++++
 tools/perf/util/pmu.c   | 20 ++++++++++++++++++++
 tools/perf/util/pmus.c  |  2 ++
 3 files changed, 31 insertions(+)

diff --git a/tools/perf/util/evsel.c b/tools/perf/util/evsel.c
index ed0d4d20e357..f5e528a5d177 100644
--- a/tools/perf/util/evsel.c
+++ b/tools/perf/util/evsel.c
@@ -50,6 +50,7 @@
 #include "off_cpu.h"
 #include "pmu.h"
 #include "pmus.h"
+#include "hwmon_pmu.h"
 #include "tool_pmu.h"
 #include "rlimit.h"
 #include "../perf-sys.h"
@@ -1680,6 +1681,9 @@ int evsel__read_counter(struct evsel *evsel, int cpu_map_idx, int thread)
 	if (evsel__is_tool(evsel))
 		return evsel__tool_pmu_read(evsel, cpu_map_idx, thread);
 
+	if (evsel__is_hwmon(evsel))
+		return evsel__hwmon_pmu_read(evsel, cpu_map_idx, thread);
+
 	if (evsel__is_retire_lat(evsel))
 		return evsel__read_retire_lat(evsel, cpu_map_idx, thread);
 
@@ -2124,6 +2128,11 @@ static int evsel__open_cpu(struct evsel *evsel, struct perf_cpu_map *cpus,
 					    start_cpu_map_idx,
 					    end_cpu_map_idx);
 	}
+	if (evsel__is_hwmon(evsel)) {
+		return evsel__hwmon_pmu_open(evsel, threads,
+					     start_cpu_map_idx,
+					     end_cpu_map_idx);
+	}
 
 	for (idx = start_cpu_map_idx; idx < end_cpu_map_idx; idx++) {
 
diff --git a/tools/perf/util/pmu.c b/tools/perf/util/pmu.c
index 0789758598c0..a02df2c80f42 100644
--- a/tools/perf/util/pmu.c
+++ b/tools/perf/util/pmu.c
@@ -18,6 +18,7 @@
 #include "debug.h"
 #include "evsel.h"
 #include "pmu.h"
+#include "hwmon_pmu.h"
 #include "pmus.h"
 #include "tool_pmu.h"
 #include <util/pmu-bison.h>
@@ -1529,6 +1530,9 @@ int perf_pmu__config_terms(const struct perf_pmu *pmu,
 {
 	struct parse_events_term *term;
 
+	if (perf_pmu__is_hwmon(pmu))
+		return hwmon_pmu__config_terms(pmu, attr, terms, err);
+
 	list_for_each_entry(term, &terms->terms, list) {
 		if (pmu_config_term(pmu, attr, term, terms, zero, apply_hardcoded, err))
 			return -EINVAL;
@@ -1661,6 +1665,11 @@ int perf_pmu__check_alias(struct perf_pmu *pmu, struct parse_events_terms *head_
 	info->scale    = 0.0;
 	info->snapshot = false;
 
+	if (perf_pmu__is_hwmon(pmu)) {
+		ret = hwmon_pmu__check_alias(head_terms, info, err);
+		goto out;
+	}
+
 	/* Fake PMU doesn't rewrite terms. */
 	if (perf_pmu__is_fake(pmu))
 		goto out;
@@ -1834,6 +1843,8 @@ 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_hwmon(pmu))
+		return hwmon_pmu__have_event(pmu, name);
 	if (perf_pmu__find_alias(pmu, name, /*load=*/ true) != NULL)
 		return true;
 	if (pmu->cpu_aliases_added || !pmu->events_table)
@@ -1845,6 +1856,9 @@ size_t perf_pmu__num_events(struct perf_pmu *pmu)
 {
 	size_t nr;
 
+	if (perf_pmu__is_hwmon(pmu))
+		return hwmon_pmu__num_events(pmu);
+
 	pmu_aliases_parse(pmu);
 	nr = pmu->sysfs_aliases + pmu->sys_json_aliases;
 
@@ -1908,6 +1922,9 @@ int perf_pmu__for_each_event(struct perf_pmu *pmu, bool skip_duplicate_pmus,
 	int ret = 0;
 	struct strbuf sb;
 
+	if (perf_pmu__is_hwmon(pmu))
+		return hwmon_pmu__for_each_event(pmu, state, cb);
+
 	strbuf_init(&sb, /*hint=*/ 0);
 	pmu_aliases_parse(pmu);
 	pmu_add_cpu_aliases(pmu);
@@ -2303,6 +2320,9 @@ int perf_pmu__pathname_fd(int dirfd, const char *pmu_name, const char *filename,
 
 void perf_pmu__delete(struct perf_pmu *pmu)
 {
+	if (perf_pmu__is_hwmon(pmu))
+		hwmon_pmu__exit(pmu);
+
 	perf_pmu__del_formats(&pmu->format);
 	perf_pmu__del_aliases(pmu);
 	perf_pmu__del_caps(pmu);
diff --git a/tools/perf/util/pmus.c b/tools/perf/util/pmus.c
index 107de86c2637..5c3e88adb9e6 100644
--- a/tools/perf/util/pmus.c
+++ b/tools/perf/util/pmus.c
@@ -15,6 +15,7 @@
 #include "evsel.h"
 #include "pmus.h"
 #include "pmu.h"
+#include "hwmon_pmu.h"
 #include "tool_pmu.h"
 #include "print-events.h"
 #include "strbuf.h"
@@ -234,6 +235,7 @@ static void pmu_read_sysfs(bool core_only)
 	if (!core_only) {
 		tool_pmu = perf_pmus__tool_pmu();
 		list_add_tail(&tool_pmu->list, &other_pmus);
+		perf_pmus__read_hwmon_pmus(&other_pmus);
 	}
 	list_sort(NULL, &other_pmus, pmus_cmp);
 	if (!list_empty(&core_pmus)) {
-- 
2.47.0.105.g07ac214952-goog

[PATCH v5 4/5] perf test: Add hwmon "PMU" test

[Ian Rogers]

Based on a mix of the sysfs PMU test (for creating the reference
files) and the tool PMU test, test that parsing given hwmon events
with there aliases creates the expected config values.

Signed-off-by: Ian Rogers <irogers@google.com>
---
 tools/perf/tests/Build          |   1 +
 tools/perf/tests/builtin-test.c |   1 +
 tools/perf/tests/hwmon_pmu.c    | 243 ++++++++++++++++++++++++++++++++
 tools/perf/tests/tests.h        |   1 +
 tools/perf/util/pmus.c          |   7 +
 tools/perf/util/pmus.h          |   3 +
 6 files changed, 256 insertions(+)
 create mode 100644 tools/perf/tests/hwmon_pmu.c

diff --git a/tools/perf/tests/Build b/tools/perf/tests/Build
index a771e4928247..078d2580d46c 100644
--- a/tools/perf/tests/Build
+++ b/tools/perf/tests/Build
@@ -67,6 +67,7 @@ perf-test-y += sigtrap.o
 perf-test-y += event_groups.o
 perf-test-y += symbols.o
 perf-test-y += util.o
+perf-test-y += hwmon_pmu.o
 perf-test-y += tool_pmu.o
 
 ifeq ($(SRCARCH),$(filter $(SRCARCH),x86 arm arm64 powerpc))
diff --git a/tools/perf/tests/builtin-test.c b/tools/perf/tests/builtin-test.c
index 3b30f258c395..81c0f12b8820 100644
--- a/tools/perf/tests/builtin-test.c
+++ b/tools/perf/tests/builtin-test.c
@@ -73,6 +73,7 @@ static struct test_suite *generic_tests[] = {
 	&suite__PERF_RECORD,
 	&suite__pmu,
 	&suite__pmu_events,
+	&suite__hwmon_pmu,
 	&suite__tool_pmu,
 	&suite__dso_data,
 	&suite__perf_evsel__roundtrip_name_test,
diff --git a/tools/perf/tests/hwmon_pmu.c b/tools/perf/tests/hwmon_pmu.c
new file mode 100644
index 000000000000..e32b7804661b
--- /dev/null
+++ b/tools/perf/tests/hwmon_pmu.c
@@ -0,0 +1,243 @@
+// SPDX-License-Identifier: (LGPL-2.1 OR BSD-2-Clause)
+#include "debug.h"
+#include "evlist.h"
+#include "parse-events.h"
+#include "tests.h"
+#include "hwmon_pmu.h"
+#include <fcntl.h>
+#include <sys/stat.h>
+
+static const struct test_event {
+	const char *name;
+	const char *alias;
+	long config;
+} test_events[] = {
+	{
+		"temp_test_hwmon_event1",
+		"temp1",
+		0xA0001,
+	},
+	{
+		"temp_test_hwmon_event2",
+		"temp2",
+		0xA0002,
+	},
+};
+
+/* Cleanup test PMU directory. */
+static int test_pmu_put(const char *dir, struct perf_pmu *hwm)
+{
+	char buf[PATH_MAX + 20];
+	int ret;
+
+	if (scnprintf(buf, sizeof(buf), "rm -fr %s", dir) < 0) {
+		pr_err("Failure to set up buffer for \"%s\"\n", dir);
+		return -EINVAL;
+	}
+	ret = system(buf);
+	if (ret)
+		pr_err("Failure to \"%s\"\n", buf);
+
+	perf_pmu__delete(hwm);
+	return ret;
+}
+
+/*
+ * Prepare test PMU directory data, normally exported by kernel at
+ * /sys/class/hwmon/hwmon<number>/. Give as input a buffer to hold the file
+ * path, the result is PMU loaded using that directory.
+ */
+static struct perf_pmu *test_pmu_get(char *dir, size_t sz)
+{
+	const char *test_hwmon_name_nl = "A test hwmon PMU\n";
+	const char *test_hwmon_name = "A test hwmon PMU";
+	/* Simulated hwmon items. */
+	const struct test_item {
+		const char *name;
+		const char *value;
+	} test_items[] = {
+		{ "temp1_label", "test hwmon event1\n", },
+		{ "temp1_input", "40000\n", },
+		{ "temp2_label", "test hwmon event2\n", },
+		{ "temp2_input", "50000\n", },
+	};
+	int dirfd, file;
+	struct perf_pmu *hwm = NULL;
+	ssize_t len;
+
+	/* Create equivalent of sysfs mount point. */
+	scnprintf(dir, sz, "/tmp/perf-hwmon-pmu-test-XXXXXX");
+	if (!mkdtemp(dir)) {
+		pr_err("mkdtemp failed\n");
+		dir[0] = '\0';
+		return NULL;
+	}
+	dirfd = open(dir, O_DIRECTORY);
+	if (dirfd < 0) {
+		pr_err("Failed to open test directory \"%s\"\n", dir);
+		goto err_out;
+	}
+
+	/* Create the test hwmon directory and give it a name. */
+	if (mkdirat(dirfd, "hwmon1234", 0755) < 0) {
+		pr_err("Failed to mkdir hwmon directory\n");
+		goto err_out;
+	}
+	file = openat(dirfd, "hwmon1234/name", O_WRONLY | O_CREAT, 0600);
+	if (!file) {
+		pr_err("Failed to open for writing file \"name\"\n");
+		goto err_out;
+	}
+	len = strlen(test_hwmon_name_nl);
+	if (write(file, test_hwmon_name_nl, len) < len) {
+		close(file);
+		pr_err("Failed to write to 'name' file\n");
+		goto err_out;
+	}
+	close(file);
+
+	/* Create test hwmon files. */
+	for (size_t i = 0; i < ARRAY_SIZE(test_items); i++) {
+		const struct test_item *item = &test_items[i];
+
+		file = openat(dirfd, item->name, O_WRONLY | O_CREAT, 0600);
+		if (!file) {
+			pr_err("Failed to open for writing file \"%s\"\n", item->name);
+			goto err_out;
+		}
+
+		if (write(file, item->value, strlen(item->value)) < 0) {
+			pr_err("Failed to write to file \"%s\"\n", item->name);
+			close(file);
+			goto err_out;
+		}
+		close(file);
+	}
+
+	/* Make the PMU reading the files created above. */
+	hwm = perf_pmus__add_test_hwmon_pmu(dirfd, "hwmon1234", test_hwmon_name);
+	if (!hwm)
+		pr_err("Test hwmon creation failed\n");
+
+err_out:
+	if (!hwm) {
+		test_pmu_put(dir, hwm);
+		if (dirfd >= 0)
+			close(dirfd);
+	}
+	return hwm;
+}
+
+static int do_test(size_t i, bool with_pmu, bool with_alias)
+{
+	const char *test_event = with_alias ? test_events[i].alias : test_events[i].name;
+	struct evlist *evlist = evlist__new();
+	struct evsel *evsel;
+	struct parse_events_error err;
+	int ret;
+	char str[128];
+	bool found = false;
+
+	if (!evlist) {
+		pr_err("evlist allocation failed\n");
+		return TEST_FAIL;
+	}
+
+	if (with_pmu)
+		snprintf(str, sizeof(str), "/%s/", test_event);
+	else
+		strlcpy(str, test_event, sizeof(str));
+
+	pr_debug("Testing '%s'\n", str);
+	parse_events_error__init(&err);
+	ret = parse_events(evlist, str, &err);
+	if (ret) {
+		evlist__delete(evlist);
+
+		pr_debug("FAILED %s:%d failed to parse event '%s', err %d\n",
+			 __FILE__, __LINE__, str, ret);
+		parse_events_error__print(&err, str);
+		ret = TEST_FAIL;
+		goto out;
+	}
+
+	ret = TEST_OK;
+	if (with_pmu ? (evlist->core.nr_entries != 1) : (evlist->core.nr_entries < 1)) {
+		pr_debug("FAILED %s:%d Unexpected number of events for '%s' of %d\n",
+			 __FILE__, __LINE__, str, evlist->core.nr_entries);
+		ret = TEST_FAIL;
+		goto out;
+	}
+
+	evlist__for_each_entry(evlist, evsel) {
+		if (!perf_pmu__is_hwmon(evsel->pmu))
+			continue;
+
+		if (evsel->core.attr.config != (u64)test_events[i].config) {
+			pr_debug("FAILED %s:%d Unexpected config for '%s', %lld != %ld\n",
+				__FILE__, __LINE__, str,
+				evsel->core.attr.config,
+				test_events[i].config);
+			ret = TEST_FAIL;
+			goto out;
+		}
+		found = true;
+	}
+
+	if (!found) {
+		pr_debug("FAILED %s:%d Didn't find hwmon event '%s' in parsed evsels\n",
+			 __FILE__, __LINE__, str);
+		ret = TEST_FAIL;
+	}
+
+out:
+	evlist__delete(evlist);
+	return ret;
+}
+
+static int test__hwmon_pmu(bool with_pmu)
+{
+	char dir[PATH_MAX];
+	struct perf_pmu *pmu = test_pmu_get(dir, sizeof(dir));
+	int ret = TEST_OK;
+
+	if (!pmu)
+		return TEST_FAIL;
+
+	for (size_t i = 0; i < ARRAY_SIZE(test_events); i++) {
+		ret = do_test(i, with_pmu, /*with_alias=*/false);
+
+		if (ret != TEST_OK)
+			break;
+
+		ret = do_test(i, with_pmu, /*with_alias=*/true);
+
+		if (ret != TEST_OK)
+			break;
+	}
+	test_pmu_put(dir, pmu);
+	return ret;
+}
+
+static int test__hwmon_pmu_without_pmu(struct test_suite *test __maybe_unused,
+				      int subtest __maybe_unused)
+{
+	return test__hwmon_pmu(/*with_pmu=*/false);
+}
+
+static int test__hwmon_pmu_with_pmu(struct test_suite *test __maybe_unused,
+				   int subtest __maybe_unused)
+{
+	return test__hwmon_pmu(/*with_pmu=*/false);
+}
+
+static struct test_case tests__hwmon_pmu[] = {
+	TEST_CASE("Parsing without PMU name", hwmon_pmu_without_pmu),
+	TEST_CASE("Parsing with PMU name", hwmon_pmu_with_pmu),
+	{	.name = NULL, }
+};
+
+struct test_suite suite__hwmon_pmu = {
+	.desc = "Hwmon PMU",
+	.test_cases = tests__hwmon_pmu,
+};
diff --git a/tools/perf/tests/tests.h b/tools/perf/tests/tests.h
index 1ed76d4156b6..260daa77eb06 100644
--- a/tools/perf/tests/tests.h
+++ b/tools/perf/tests/tests.h
@@ -83,6 +83,7 @@ DECLARE_SUITE(perf_evsel__tp_sched_test);
 DECLARE_SUITE(syscall_openat_tp_fields);
 DECLARE_SUITE(pmu);
 DECLARE_SUITE(pmu_events);
+DECLARE_SUITE(hwmon_pmu);
 DECLARE_SUITE(tool_pmu);
 DECLARE_SUITE(attr);
 DECLARE_SUITE(dso_data);
diff --git a/tools/perf/util/pmus.c b/tools/perf/util/pmus.c
index 5c3e88adb9e6..451c6e00ad70 100644
--- a/tools/perf/util/pmus.c
+++ b/tools/perf/util/pmus.c
@@ -733,6 +733,13 @@ struct perf_pmu *perf_pmus__add_test_pmu(int test_sysfs_dirfd, const char *name)
 	return perf_pmu__lookup(&other_pmus, test_sysfs_dirfd, name, /*eager_load=*/true);
 }
 
+struct perf_pmu *perf_pmus__add_test_hwmon_pmu(int hwmon_dir,
+					       const char *sysfs_name,
+					       const char *name)
+{
+	return hwmon_pmu__new(&other_pmus, hwmon_dir, sysfs_name, name);
+}
+
 struct perf_pmu *perf_pmus__fake_pmu(void)
 {
 	static struct perf_pmu fake = {
diff --git a/tools/perf/util/pmus.h b/tools/perf/util/pmus.h
index e1742b56eec7..a0cb0eb2ff97 100644
--- a/tools/perf/util/pmus.h
+++ b/tools/perf/util/pmus.h
@@ -30,6 +30,9 @@ bool perf_pmus__supports_extended_type(void);
 char *perf_pmus__default_pmu_name(void);
 
 struct perf_pmu *perf_pmus__add_test_pmu(int test_sysfs_dirfd, const char *name);
+struct perf_pmu *perf_pmus__add_test_hwmon_pmu(int hwmon_dir,
+					       const char *sysfs_name,
+					       const char *name);
 struct perf_pmu *perf_pmus__fake_pmu(void);
 
 #endif /* __PMUS_H */
-- 
2.47.0.105.g07ac214952-goog

[PATCH v5 5/5] perf docs: Document tool and hwmon events

[Ian Rogers]

Add a few paragraphs on tool and hwmon events.

Signed-off-by: Ian Rogers <irogers@google.com>
---
 tools/perf/Documentation/perf-list.txt | 15 +++++++++++++++
 1 file changed, 15 insertions(+)

diff --git a/tools/perf/Documentation/perf-list.txt b/tools/perf/Documentation/perf-list.txt
index 14621f39b375..d0c65fad419a 100644
--- a/tools/perf/Documentation/perf-list.txt
+++ b/tools/perf/Documentation/perf-list.txt
@@ -243,6 +243,21 @@ For accessing trace point events perf needs to have read access to
 /sys/kernel/tracing, even when perf_event_paranoid is in a relaxed
 setting.
 
+TOOL/HWMON EVENTS
+-----------------
+
+Some events don't have an associated PMU instead reading values
+available to software without perf_event_open. As these events don't
+support sampling they can only really be read by tools like perf stat.
+
+Tool events provide times and certain system parameters. Examples
+include duration_time, user_time, system_time and num_cpus_online.
+
+Hwmon events provide easy access to hwmon sysfs data typically in
+/sys/class/hwmon. This information includes temperatures, fan speeds
+and energy usage.
+
+
 TRACING
 -------
 
-- 
2.47.0.105.g07ac214952-goog

Re: [PATCH v5 2/5] perf hwmon_pmu: Add a tool PMU exposing events from hwmon in sysfs

[kernel test robot]

Hi Ian,

kernel test robot noticed the following build errors:

[auto build test ERROR on perf-tools-next/perf-tools-next]
[also build test ERROR on next-20241018]
[cannot apply to tip/perf/core perf-tools/perf-tools linus/master acme/perf/core v6.12-rc3]
[If your patch is applied to the wrong git tree, kindly drop us a note.
And when submitting patch, we suggest to use '--base' as documented in
https://git-scm.com/docs/git-format-patch#_base_tree_information]

url:    https://github.com/intel-lab-lkp/linux/commits/Ian-Rogers/tools-api-io-Ensure-line_len_out-is-always-initialized/20241017-143759
base:   https://git.kernel.org/pub/scm/linux/kernel/git/perf/perf-tools-next.git perf-tools-next
patch link:    https://lore.kernel.org/r/20241017063555.366065-3-irogers%40google.com
patch subject: [PATCH v5 2/5] perf hwmon_pmu: Add a tool PMU exposing events from hwmon in sysfs
compiler: gcc-12 (Debian 12.2.0-14) 12.2.0
reproduce (this is a W=1 build): (https://download.01.org/0day-ci/archive/20241021/202410210800.pNLlo3bN-lkp@intel.com/reproduce)

If you fix the issue in a separate patch/commit (i.e. not just a new version of
the same patch/commit), kindly add following tags
| Reported-by: kernel test robot <lkp@intel.com>
| Closes: https://lore.kernel.org/oe-kbuild-all/202410210800.pNLlo3bN-lkp@intel.com/

All errors (new ones prefixed by >>):

   Makefile.config:665: No libunwind found. Please install libunwind-dev[el] >= 1.1 and/or set LIBUNWIND_DIR
     PERF_VERSION = 6.12.rc3.gd8463b89755f
   util/hwmon_pmu.c: In function 'parse_hwmon_filename':
>> util/hwmon_pmu.c:175:9: error: implicit declaration of function 'strlcpy'; did you mean 'strncpy'? [-Werror=implicit-function-declaration]
     175 |         strlcpy(fn_type, filename, sizeof(fn_type));
         |         ^~~~~~~
         |         strncpy
   cc1: all warnings being treated as errors
   make[7]: *** [tools/build/Makefile.build:106: tools/perf/util/hwmon_pmu.o] Error 1
   make[7]: *** Waiting for unfinished jobs....
   make[6]: *** [tools/build/Makefile.build:158: util] Error 2
   make[5]: *** [Makefile.perf:789: tools/perf/perf-util-in.o] Error 2
   make[5]: *** Waiting for unfinished jobs....
   make[4]: *** [Makefile.perf:292: sub-make] Error 2
   make[3]: *** [Makefile:76: all] Error 2

-- 
0-DAY CI Kernel Test Service
https://github.com/intel/lkp-tests/wiki

Re: [PATCH v5 4/5] perf test: Add hwmon "PMU" test

[kernel test robot]

Hi Ian,

kernel test robot noticed the following build errors:

[auto build test ERROR on perf-tools-next/perf-tools-next]
[also build test ERROR on next-20241021]
[cannot apply to tip/perf/core perf-tools/perf-tools linus/master acme/perf/core v6.12-rc4]
[If your patch is applied to the wrong git tree, kindly drop us a note.
And when submitting patch, we suggest to use '--base' as documented in
https://git-scm.com/docs/git-format-patch#_base_tree_information]

url:    https://github.com/intel-lab-lkp/linux/commits/Ian-Rogers/tools-api-io-Ensure-line_len_out-is-always-initialized/20241017-143759
base:   https://git.kernel.org/pub/scm/linux/kernel/git/perf/perf-tools-next.git perf-tools-next
patch link:    https://lore.kernel.org/r/20241017063555.366065-5-irogers%40google.com
patch subject: [PATCH v5 4/5] perf test: Add hwmon "PMU" test
compiler: gcc-12 (Debian 12.2.0-14) 12.2.0
reproduce (this is a W=1 build): (https://download.01.org/0day-ci/archive/20241021/202410212129.7qRTRilb-lkp@intel.com/reproduce)

If you fix the issue in a separate patch/commit (i.e. not just a new version of
the same patch/commit), kindly add following tags
| Reported-by: kernel test robot <lkp@intel.com>
| Closes: https://lore.kernel.org/oe-kbuild-all/202410212129.7qRTRilb-lkp@intel.com/

All errors (new ones prefixed by >>):

   Makefile.config:665: No libunwind found. Please install libunwind-dev[el] >= 1.1 and/or set LIBUNWIND_DIR
     PERF_VERSION = 6.12.rc3.g552cc7c00b6d
   tests/hwmon_pmu.c: In function 'do_test':
>> tests/hwmon_pmu.c:149:17: error: implicit declaration of function 'strlcpy'; did you mean 'strncpy'? [-Werror=implicit-function-declaration]
     149 |                 strlcpy(str, test_event, sizeof(str));
         |                 ^~~~~~~
         |                 strncpy
   cc1: all warnings being treated as errors
   make[7]: *** [tools/build/Makefile.build:105: tools/perf/tests/hwmon_pmu.o] Error 1
   make[7]: *** Waiting for unfinished jobs....
   make[6]: *** [tools/build/Makefile.build:158: tests] Error 2
   make[5]: *** [Makefile.perf:777: tools/perf/perf-test-in.o] Error 2
   make[5]: *** Waiting for unfinished jobs....
   util/hwmon_pmu.c: In function 'parse_hwmon_filename':
   util/hwmon_pmu.c:175:9: error: implicit declaration of function 'strlcpy'; did you mean 'strncpy'? [-Werror=implicit-function-declaration]
     175 |         strlcpy(fn_type, filename, sizeof(fn_type));
         |         ^~~~~~~
         |         strncpy
   cc1: all warnings being treated as errors
   make[7]: *** [tools/build/Makefile.build:106: tools/perf/util/hwmon_pmu.o] Error 1
   make[7]: *** Waiting for unfinished jobs....
   make[6]: *** [tools/build/Makefile.build:158: util] Error 2
   make[5]: *** [Makefile.perf:789: tools/perf/perf-util-in.o] Error 2
   make[4]: *** [Makefile.perf:292: sub-make] Error 2
   make[3]: *** [Makefile:76: all] Error 2

-- 
0-DAY CI Kernel Test Service
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Re: [PATCH v5 2/5] perf hwmon_pmu: Add a tool PMU exposing events from hwmon in sysfs

[kernel test robot]

Hi Ian,

kernel test robot noticed the following build errors:

[auto build test ERROR on perf-tools-next/perf-tools-next]
[also build test ERROR on next-20241022]
[cannot apply to tip/perf/core perf-tools/perf-tools linus/master acme/perf/core v6.12-rc4]
[If your patch is applied to the wrong git tree, kindly drop us a note.
And when submitting patch, we suggest to use '--base' as documented in
https://git-scm.com/docs/git-format-patch#_base_tree_information]

url:    https://github.com/intel-lab-lkp/linux/commits/Ian-Rogers/tools-api-io-Ensure-line_len_out-is-always-initialized/20241017-143759
base:   https://git.kernel.org/pub/scm/linux/kernel/git/perf/perf-tools-next.git perf-tools-next
patch link:    https://lore.kernel.org/r/20241017063555.366065-3-irogers%40google.com
patch subject: [PATCH v5 2/5] perf hwmon_pmu: Add a tool PMU exposing events from hwmon in sysfs
compiler: clang version 18.1.8 (https://github.com/llvm/llvm-project 3b5b5c1ec4a3095ab096dd780e84d7ab81f3d7ff)
reproduce (this is a W=1 build): (https://download.01.org/0day-ci/archive/20241022/202410221809.rM67Lxz0-lkp@intel.com/reproduce)

If you fix the issue in a separate patch/commit (i.e. not just a new version of
the same patch/commit), kindly add following tags
| Reported-by: kernel test robot <lkp@intel.com>
| Closes: https://lore.kernel.org/oe-kbuild-all/202410221809.rM67Lxz0-lkp@intel.com/

All errors (new ones prefixed by >>):

   Makefile.config:665: No libunwind found. Please install libunwind-dev[el] >= 1.1 and/or set LIBUNWIND_DIR
     PERF_VERSION = 6.12.rc3.gd8463b89755f
>> util/hwmon_pmu.c:175:2: error: call to undeclared library function 'strlcpy' with type 'unsigned long (char *, const char *, unsigned long)'; ISO C99 and later do not support implicit function declarations [-Wimplicit-function-declaration]
     175 |         strlcpy(fn_type, filename, sizeof(fn_type));
         |         ^
   util/hwmon_pmu.c:175:2: note: include the header <string.h> or explicitly provide a declaration for 'strlcpy'
   1 error generated.
   make[7]: *** [tools/build/Makefile.build:106: tools/perf/util/hwmon_pmu.o] Error 1
   make[7]: *** Waiting for unfinished jobs....
   make[6]: *** [tools/build/Makefile.build:158: util] Error 2
   make[5]: *** [Makefile.perf:789: tools/perf/perf-util-in.o] Error 2
   make[5]: *** Waiting for unfinished jobs....
   make[4]: *** [Makefile.perf:292: sub-make] Error 2
   make[3]: *** [Makefile:76: all] Error 2

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