perf hwmon_pmu: Add hwmon filename parser
authorIan Rogers <irogers@google.com>
Sat, 9 Nov 2024 00:37:54 +0000 (16:37 -0800)
committerNamhyung Kim <namhyung@kernel.org>
Sat, 9 Nov 2024 16:26:53 +0000 (08:26 -0800)
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>
Cc: Ravi Bangoria <ravi.bangoria@amd.com>
Cc: Yoshihiro Furudera <fj5100bi@fujitsu.com>
Cc: Howard Chu <howardchu95@gmail.com>
Cc: Ze Gao <zegao2021@gmail.com>
Cc: Changbin Du <changbin.du@huawei.com>
Cc: Junhao He <hejunhao3@huawei.com>
Cc: Weilin Wang <weilin.wang@intel.com>
Cc: James Clark <james.clark@linaro.org>
Cc: Oliver Upton <oliver.upton@linux.dev>
Cc: Athira Jajeev <atrajeev@linux.vnet.ibm.com>
[namhyung: add #include <linux/string.h> for strlcpy()]
Link: https://lore.kernel.org/r/20241109003759.473460-3-irogers@google.com
Signed-off-by: Namhyung Kim <namhyung@kernel.org>
tools/perf/util/Build
tools/perf/util/hwmon_pmu.c [new file with mode: 0644]
tools/perf/util/hwmon_pmu.h [new file with mode: 0644]

index 1eedead..78b990c 100644 (file)
@@ -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 (file)
index 0000000..301793b
--- /dev/null
@@ -0,0 +1,145 @@
+// 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>
+#include <linux/string.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 (file)
index 0000000..df0ab5f
--- /dev/null
@@ -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 */