[PATCH v8 0/7] Hwmon PMUs

[PATCH v8 0/7] 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]
...
```

v8: Fix formatting issues and reduce scope of 2 strings reported by
    Namhyung.
v7: Try to address feedback from Namhyung wrt size/comprehensibility
    of the hwmon PMU patch. To better explain the config encoding put
    the parser into a patch ahead of the PMU patch and add a unit
    test. This shows how a hwmon filename can be moved back-and-forth
    with a config value as a single patch (two with the test). The
    hwmon PMU patch is then putting the wrapping around that for the
    pmus', parse_event's and evsel reading's benefit.
    
    The alternate approach of not caring about the mapping, name to
    config value, and using the evsel->name wasn't followed. In the
    tool PMU it was made so we can go back-and-forth between event
    names and a type+config, this removed the tool enum value from the
    evsel as now tool events were more 1st class and evsel should
    really just be a wrapper on a perf_event_attr. Using the
    evsel->name wasn't doing that and so the approach of mapping
    filenames and configs, as better highlighted in this series was
    pursued.

    It is expected future PMUs won't be able to cleanly map fixed
    strings to config values, in those cases tables would be
    necessary. Making a hwmon PMU do this and then removing it to
    follow the parsing/mapping done in patch 2 here, would have been a
    lot of additional work which then would be removed.

v6: Add string.h #include for issue reported by kernel test robot.
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 (7):
  tools api io: Ensure line_len_out is always initialized
  perf hwmon_pmu: Add hwmon filename parser
  perf test: Add hwmon filename parser test
  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           | 340 ++++++++++
 tools/perf/tests/tests.h               |   1 +
 tools/perf/util/Build                  |   1 +
 tools/perf/util/evsel.c                |   9 +
 tools/perf/util/hwmon_pmu.c            | 826 +++++++++++++++++++++++++
 tools/perf/util/hwmon_pmu.h            | 156 +++++
 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, 1385 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

-- 
2.47.0.277.g8800431eea-goog

[PATCH v8 1/7] 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;
 }
 
-- 
2.47.0.277.g8800431eea-goog

[PATCH v8 2/7] perf hwmon_pmu: Add hwmon filename parser

[Ian Rogers]

hwmon filenames have a specific encoding that will be used to give a
config value. The encoding is described in:
Documentation/hwmon/sysfs-interface.rst
Add a function to parse the filename into consituent enums/ints that
will then be amenable to config encoding.

Note, things are done this way to allow mapping names to config and
back without the use of hash/dynamic lookup tables.

Signed-off-by: Ian Rogers <irogers@google.com>
---
 tools/perf/util/Build       |   1 +
 tools/perf/util/hwmon_pmu.c | 144 ++++++++++++++++++++++++++++++++++++
 tools/perf/util/hwmon_pmu.h | 111 +++++++++++++++++++++++++++
 3 files changed, 256 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 1eedead5f2f2..78b990c04f71 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..8791e55097dc
--- /dev/null
+++ b/tools/perf/util/hwmon_pmu.c
@@ -0,0 +1,144 @@
+// SPDX-License-Identifier: (LGPL-2.1 OR BSD-2-Clause)
+#include "debug.h"
+#include "hwmon_pmu.h"
+#include <assert.h>
+#include <stddef.h>
+#include <stdlib.h>
+#include <string.h>
+#include <linux/kernel.h>
+
+/** Strings that correspond to enum hwmon_type. */
+static 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"
+
+/** Strings that correspond to enum hwmon_item. */
+static 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"
+
+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 - 5);
+		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;
+}
diff --git a/tools/perf/util/hwmon_pmu.h b/tools/perf/util/hwmon_pmu.h
new file mode 100644
index 000000000000..df0ab5ff7534
--- /dev/null
+++ b/tools/perf/util/hwmon_pmu.h
@@ -0,0 +1,111 @@
+/* SPDX-License-Identifier: (LGPL-2.1 OR BSD-2-Clause) */
+#ifndef __HWMON_PMU_H
+#define __HWMON_PMU_H
+
+#include <stdbool.h>
+
+/**
+ * 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,
+};
+
+/**
+ * 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);
+
+#endif /* __HWMON_PMU_H */
-- 
2.47.0.277.g8800431eea-goog

[PATCH v8 3/7] perf test: Add hwmon filename parser test

[Ian Rogers]

Filename parsing maps a hwmon filename to constituent parts enum/int
parts for the hwmon config value. Add a test case for the parsing.

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    | 110 ++++++++++++++++++++++++++++++++
 tools/perf/tests/tests.h        |   1 +
 4 files changed, 113 insertions(+)
 create mode 100644 tools/perf/tests/hwmon_pmu.c

diff --git a/tools/perf/tests/Build b/tools/perf/tests/Build
index 01ed9335db4d..ec4e1f034742 100644
--- a/tools/perf/tests/Build
+++ b/tools/perf/tests/Build
@@ -66,6 +66,7 @@ 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 d2cabaa8ad92..8dcf74d3c0a3 100644
--- a/tools/perf/tests/builtin-test.c
+++ b/tools/perf/tests/builtin-test.c
@@ -71,6 +71,7 @@ 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..f5b58486d8d3
--- /dev/null
+++ b/tools/perf/tests/hwmon_pmu.c
@@ -0,0 +1,110 @@
+// SPDX-License-Identifier: (LGPL-2.1 OR BSD-2-Clause)
+#include "debug.h"
+#include "hwmon_pmu.h"
+#include "tests.h"
+#include <linux/compiler.h>
+#include <linux/kernel.h>
+
+static int test__parse_hwmon_filename(struct test_suite *test __maybe_unused,
+				      int subtest __maybe_unused)
+{
+	const struct hwmon_parse_test {
+		const char *filename;
+		enum hwmon_type type;
+		int number;
+		enum hwmon_item item;
+		bool alarm;
+		bool parse_ok;
+	} tests[] = {
+		{
+			.filename = "cpu0_accuracy",
+			.type = HWMON_TYPE_CPU,
+			.number = 0,
+			.item = HWMON_ITEM_ACCURACY,
+			.alarm = false,
+			.parse_ok = true,
+		},
+		{
+			.filename = "temp1_input",
+			.type = HWMON_TYPE_TEMP,
+			.number = 1,
+			.item = HWMON_ITEM_INPUT,
+			.alarm = false,
+			.parse_ok = true,
+		},
+		{
+			.filename = "fan2_vid",
+			.type = HWMON_TYPE_FAN,
+			.number = 2,
+			.item = HWMON_ITEM_VID,
+			.alarm = false,
+			.parse_ok = true,
+		},
+		{
+			.filename = "power3_crit_alarm",
+			.type = HWMON_TYPE_POWER,
+			.number = 3,
+			.item = HWMON_ITEM_CRIT,
+			.alarm = true,
+			.parse_ok = true,
+		},
+		{
+			.filename = "intrusion4_average_interval_min_alarm",
+			.type = HWMON_TYPE_INTRUSION,
+			.number = 4,
+			.item = HWMON_ITEM_AVERAGE_INTERVAL_MIN,
+			.alarm = true,
+			.parse_ok = true,
+		},
+		{
+			.filename = "badtype5_baditem",
+			.type = HWMON_TYPE_NONE,
+			.number = 5,
+			.item = HWMON_ITEM_NONE,
+			.alarm = false,
+			.parse_ok = false,
+		},
+		{
+			.filename = "humidity6_baditem",
+			.type = HWMON_TYPE_NONE,
+			.number = 6,
+			.item = HWMON_ITEM_NONE,
+			.alarm = false,
+			.parse_ok = false,
+		},
+	};
+
+	for (size_t i = 0; i < ARRAY_SIZE(tests); i++) {
+		enum hwmon_type type;
+		int number;
+		enum hwmon_item item;
+		bool alarm;
+
+		TEST_ASSERT_EQUAL("parse_hwmon_filename",
+				parse_hwmon_filename(
+					tests[i].filename,
+					&type,
+					&number,
+					&item,
+					&alarm),
+				tests[i].parse_ok
+			);
+		if (tests[i].parse_ok) {
+			TEST_ASSERT_EQUAL("parse_hwmon_filename type", type, tests[i].type);
+			TEST_ASSERT_EQUAL("parse_hwmon_filename number", number, tests[i].number);
+			TEST_ASSERT_EQUAL("parse_hwmon_filename item", item, tests[i].item);
+			TEST_ASSERT_EQUAL("parse_hwmon_filename alarm", alarm, tests[i].alarm);
+		}
+	}
+	return TEST_OK;
+}
+
+static struct test_case tests__hwmon_pmu[] = {
+	TEST_CASE("Basic parsing test", parse_hwmon_filename),
+	{	.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 af284dd47e5c..cb58b43aa063 100644
--- a/tools/perf/tests/tests.h
+++ b/tools/perf/tests/tests.h
@@ -92,6 +92,7 @@ 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);
-- 
2.47.0.277.g8800431eea-goog

[PATCH v8 4/7] 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/hwmon_pmu.c | 682 ++++++++++++++++++++++++++++++++++++
 tools/perf/util/hwmon_pmu.h |  45 +++
 tools/perf/util/pmu.h       |   2 +
 3 files changed, 729 insertions(+)

diff --git a/tools/perf/util/hwmon_pmu.c b/tools/perf/util/hwmon_pmu.c
index 8791e55097dc..89acc19347c8 100644
--- a/tools/perf/util/hwmon_pmu.c
+++ b/tools/perf/util/hwmon_pmu.c
@@ -1,11 +1,25 @@
 // 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 <assert.h>
+#include <ctype.h>
+#include <dirent.h>
+#include <fcntl.h>
 #include <stddef.h>
 #include <stdlib.h>
 #include <string.h>
+#include <api/fs/fs.h>
+#include <api/io.h>
 #include <linux/kernel.h>
+#include <linux/zalloc.h>
 
 /** Strings that correspond to enum hwmon_type. */
 static const char * const hwmon_type_strs[HWMON_TYPE_MAX] = {
@@ -72,6 +86,79 @@ static const char * const hwmon_item_strs[HWMON_ITEM__MAX] = {
 };
 #define LONGEST_HWMON_ITEM_STR "average_interval_max"
 
+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 */
+};
+
+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;
@@ -142,3 +229,598 @@ bool parse_hwmon_filename(const char *filename,
 	*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
index df0ab5ff7534..ebfdfe3b295a 100644
--- a/tools/perf/util/hwmon_pmu.h
+++ b/tools/perf/util/hwmon_pmu.h
@@ -2,8 +2,12 @@
 #ifndef __HWMON_PMU_H
 #define __HWMON_PMU_H
 
+#include "pmu.h"
 #include <stdbool.h>
 
+struct list_head;
+struct perf_thread_map;
+
 /**
  * enum hwmon_type:
  *
@@ -87,6 +91,14 @@ enum hwmon_item {
 	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.
  *
@@ -108,4 +120,37 @@ bool parse_hwmon_filename(const char *filename,
 			  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 b86b3c3685a2..d511bf7cc9d0 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,
 };
-- 
2.47.0.277.g8800431eea-goog

[PATCH v8 5/7] 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 f780e30aa259..fc1bf86c5063 100644
--- a/tools/perf/util/evsel.c
+++ b/tools/perf/util/evsel.c
@@ -56,6 +56,7 @@
 #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"
@@ -1799,6 +1800,9 @@ 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);
 
@@ -2465,6 +2469,11 @@ 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)) {
-- 
2.47.0.277.g8800431eea-goog

[PATCH v8 6/7] 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/hwmon_pmu.c | 230 +++++++++++++++++++++++++++++++++++
 tools/perf/util/pmus.c       |   7 ++
 tools/perf/util/pmus.h       |   3 +
 3 files changed, 240 insertions(+)

diff --git a/tools/perf/tests/hwmon_pmu.c b/tools/perf/tests/hwmon_pmu.c
index f5b58486d8d3..3a95cc63fc48 100644
--- a/tools/perf/tests/hwmon_pmu.c
+++ b/tools/perf/tests/hwmon_pmu.c
@@ -1,10 +1,238 @@
 // SPDX-License-Identifier: (LGPL-2.1 OR BSD-2-Clause)
 #include "debug.h"
+#include "evlist.h"
 #include "hwmon_pmu.h"
+#include "parse-events.h"
 #include "tests.h"
+#include <fcntl.h>
+#include <sys/stat.h>
 #include <linux/compiler.h>
 #include <linux/kernel.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 int test__parse_hwmon_filename(struct test_suite *test __maybe_unused,
 				      int subtest __maybe_unused)
 {
@@ -101,6 +329,8 @@ static int test__parse_hwmon_filename(struct test_suite *test __maybe_unused,
 
 static struct test_case tests__hwmon_pmu[] = {
 	TEST_CASE("Basic parsing test", parse_hwmon_filename),
+	TEST_CASE("Parsing without PMU name", hwmon_pmu_without_pmu),
+	TEST_CASE("Parsing with PMU name", hwmon_pmu_with_pmu),
 	{	.name = NULL, }
 };
 
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 */
-- 
2.47.0.277.g8800431eea-goog

[PATCH v8 7/7] 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
 -------
 
-- 
2.47.0.277.g8800431eea-goog