diff options
| -rw-r--r-- | drivers/thermal/Kconfig | 7 | ||||
| -rw-r--r-- | drivers/thermal/Makefile | 2 | ||||
| -rw-r--r-- | drivers/thermal/thermal_core.c | 6 | ||||
| -rw-r--r-- | drivers/thermal/thermal_core.h | 1 | ||||
| -rw-r--r-- | drivers/thermal/thermal_debugfs.c | 446 | ||||
| -rw-r--r-- | drivers/thermal/thermal_debugfs.h | 14 | ||||
| -rw-r--r-- | drivers/thermal/thermal_helpers.c | 20 | ||||
| -rw-r--r-- | include/linux/thermal.h | 7 |
8 files changed, 497 insertions, 6 deletions
diff --git a/drivers/thermal/Kconfig b/drivers/thermal/Kconfig index c81a00fbca7d..3ff7add3fb7c 100644 --- a/drivers/thermal/Kconfig +++ b/drivers/thermal/Kconfig @@ -33,6 +33,13 @@ config THERMAL_STATISTICS If in doubt, say N. +config THERMAL_DEBUGFS + bool "Thermal subsystem debug support" + depends on DEBUG_FS + help + Say Y to allow the thermal subsystem to collect diagnostic + information that can be accessed via debugfs. + config THERMAL_EMERGENCY_POWEROFF_DELAY_MS int "Emergency poweroff delay in milli-seconds" default 0 diff --git a/drivers/thermal/Makefile b/drivers/thermal/Makefile index c934cab309ae..0f65ae86a9c6 100644 --- a/drivers/thermal/Makefile +++ b/drivers/thermal/Makefile @@ -10,6 +10,8 @@ thermal_sys-y += thermal_trip.o thermal_helpers.o # netlink interface to manage the thermal framework thermal_sys-$(CONFIG_THERMAL_NETLINK) += thermal_netlink.o +thermal_sys-$(CONFIG_THERMAL_DEBUGFS) += thermal_debugfs.o + # interface to/from other layers providing sensors thermal_sys-$(CONFIG_THERMAL_HWMON) += thermal_hwmon.o thermal_sys-$(CONFIG_THERMAL_OF) += thermal_of.o diff --git a/drivers/thermal/thermal_core.c b/drivers/thermal/thermal_core.c index c0b012e075f3..5d9cc422d7ba 100644 --- a/drivers/thermal/thermal_core.c +++ b/drivers/thermal/thermal_core.c @@ -960,6 +960,8 @@ __thermal_cooling_device_register(struct device_node *np, mutex_unlock(&thermal_list_lock); + thermal_debug_cdev_add(cdev); + return cdev; out_cooling_dev: @@ -1166,6 +1168,8 @@ void thermal_cooling_device_unregister(struct thermal_cooling_device *cdev) if (!cdev) return; + thermal_debug_cdev_remove(cdev); + mutex_lock(&thermal_list_lock); if (!thermal_cooling_device_present(cdev)) { @@ -1629,6 +1633,8 @@ static int __init thermal_init(void) { int result; + thermal_debug_init(); + result = thermal_netlink_init(); if (result) goto error; diff --git a/drivers/thermal/thermal_core.h b/drivers/thermal/thermal_core.h index 4e023d54fd27..e9c099ecdd0f 100644 --- a/drivers/thermal/thermal_core.h +++ b/drivers/thermal/thermal_core.h @@ -13,6 +13,7 @@ #include <linux/thermal.h> #include "thermal_netlink.h" +#include "thermal_debugfs.h" /* Default Thermal Governor */ #if defined(CONFIG_THERMAL_DEFAULT_GOV_STEP_WISE) diff --git a/drivers/thermal/thermal_debugfs.c b/drivers/thermal/thermal_debugfs.c new file mode 100644 index 000000000000..b18bdde47847 --- /dev/null +++ b/drivers/thermal/thermal_debugfs.c @@ -0,0 +1,446 @@ + +// SPDX-License-Identifier: GPL-2.0 +/* + * Copyright 2023 Linaro Limited + * + * Author: Daniel Lezcano <daniel.lezcano@linaro.org> + * + * Thermal subsystem debug support + */ +#include <linux/debugfs.h> +#include <linux/ktime.h> +#include <linux/list.h> +#include <linux/minmax.h> +#include <linux/mutex.h> +#include <linux/thermal.h> + +static struct dentry *d_root; +static struct dentry *d_cdev; + +/* + * Length of the string containing the thermal zone id or the cooling + * device id, including the ending nul character. We can reasonably + * assume there won't be more than 256 thermal zones as the maximum + * observed today is around 32. + */ +#define IDSLENGTH 4 + +/* + * The cooling device transition list is stored in a hash table where + * the size is CDEVSTATS_HASH_SIZE. The majority of cooling devices + * have dozen of states but some can have much more, so a hash table + * is more adequate in this case, because the cost of browsing the entire + * list when storing the transitions may not be negligible. + */ +#define CDEVSTATS_HASH_SIZE 16 + +/** + * struct cdev_debugfs - per cooling device statistics structure + * A cooling device can have a high number of states. Showing the + * transitions on a matrix based representation can be overkill given + * most of the transitions won't happen and we end up with a matrix + * filled with zero. Instead, we show the transitions which actually + * happened. + * + * Every transition updates the current_state and the timestamp. The + * transitions and the durations are stored in lists. + * + * @total: the number of transitions for this cooling device + * @current_state: the current cooling device state + * @timestamp: the state change timestamp + * @transitions: an array of lists containing the state transitions + * @durations: an array of lists containing the residencies of each state + */ +struct cdev_debugfs { + u32 total; + int current_state; + ktime_t timestamp; + struct list_head transitions[CDEVSTATS_HASH_SIZE]; + struct list_head durations[CDEVSTATS_HASH_SIZE]; +}; + +/** + * struct cdev_value - Common structure for cooling device entry + * + * The following common structure allows to store the information + * related to the transitions and to the state residencies. They are + * identified with a id which is associated to a value. It is used as + * nodes for the "transitions" and "durations" above. + * + * @node: node to insert the structure in a list + * @id: identifier of the value which can be a state or a transition + * @residency: a ktime_t representing a state residency duration + * @count: a number of occurrences + */ +struct cdev_record { + struct list_head node; + int id; + union { + ktime_t residency; + u64 count; + }; +}; + +/** + * struct thermal_debugfs - High level structure for a thermal object in debugfs + * + * The thermal_debugfs structure is the common structure used by the + * cooling device to compute the statistics. + * + * @d_top: top directory of the thermal object directory + * @lock: per object lock to protect the internals + * + * @cdev: a cooling device debug structure + */ +struct thermal_debugfs { + struct dentry *d_top; + struct mutex lock; + union { + struct cdev_debugfs cdev_dbg; + }; +}; + +void thermal_debug_init(void) +{ + d_root = debugfs_create_dir("thermal", NULL); + if (!d_root) + return; + + d_cdev = debugfs_create_dir("cooling_devices", d_root); +} + +static struct thermal_debugfs *thermal_debugfs_add_id(struct dentry *d, int id) +{ + struct thermal_debugfs *thermal_dbg; + char ids[IDSLENGTH]; + + thermal_dbg = kzalloc(sizeof(*thermal_dbg), GFP_KERNEL); + if (!thermal_dbg) + return NULL; + + mutex_init(&thermal_dbg->lock); + + snprintf(ids, IDSLENGTH, "%d", id); + + thermal_dbg->d_top = debugfs_create_dir(ids, d); + if (!thermal_dbg->d_top) { + kfree(thermal_dbg); + return NULL; + } + + return thermal_dbg; +} + +static void thermal_debugfs_remove_id(struct thermal_debugfs *thermal_dbg) +{ + if (!thermal_dbg) + return; + + debugfs_remove(thermal_dbg->d_top); + + kfree(thermal_dbg); +} + +static struct cdev_record * +thermal_debugfs_cdev_record_alloc(struct thermal_debugfs *thermal_dbg, + struct list_head *lists, int id) +{ + struct cdev_record *cdev_record; + + cdev_record = kzalloc(sizeof(*cdev_record), GFP_KERNEL); + if (!cdev_record) + return NULL; + + cdev_record->id = id; + INIT_LIST_HEAD(&cdev_record->node); + list_add_tail(&cdev_record->node, + &lists[cdev_record->id % CDEVSTATS_HASH_SIZE]); + + return cdev_record; +} + +static struct cdev_record * +thermal_debugfs_cdev_record_find(struct thermal_debugfs *thermal_dbg, + struct list_head *lists, int id) +{ + struct cdev_record *entry; + + list_for_each_entry(entry, &lists[id % CDEVSTATS_HASH_SIZE], node) + if (entry->id == id) + return entry; + + return NULL; +} + +static struct cdev_record * +thermal_debugfs_cdev_record_get(struct thermal_debugfs *thermal_dbg, + struct list_head *lists, int id) +{ + struct cdev_record *cdev_record; + + cdev_record = thermal_debugfs_cdev_record_find(thermal_dbg, lists, id); + if (cdev_record) + return cdev_record; + + return thermal_debugfs_cdev_record_alloc(thermal_dbg, lists, id); +} + +static void thermal_debugfs_cdev_clear(struct cdev_debugfs *cdev_dbg) +{ + int i; + struct cdev_record *entry, *tmp; + + for (i = 0; i < CDEVSTATS_HASH_SIZE; i++) { + + list_for_each_entry_safe(entry, tmp, + &cdev_dbg->transitions[i], node) { + list_del(&entry->node); + kfree(entry); + } + + list_for_each_entry_safe(entry, tmp, + &cdev_dbg->durations[i], node) { + list_del(&entry->node); + kfree(entry); + } + } + + cdev_dbg->total = 0; +} + +static void *cdev_seq_start(struct seq_file *s, loff_t *pos) +{ + struct thermal_debugfs *thermal_dbg = s->private; + + mutex_lock(&thermal_dbg->lock); + + return (*pos < CDEVSTATS_HASH_SIZE) ? pos : NULL; +} + +static void *cdev_seq_next(struct seq_file *s, void *v, loff_t *pos) +{ + (*pos)++; + + return (*pos < CDEVSTATS_HASH_SIZE) ? pos : NULL; +} + +static void cdev_seq_stop(struct seq_file *s, void *v) +{ + struct thermal_debugfs *thermal_dbg = s->private; + + mutex_unlock(&thermal_dbg->lock); +} + +static int cdev_tt_seq_show(struct seq_file *s, void *v) +{ + struct thermal_debugfs *thermal_dbg = s->private; + struct cdev_debugfs *cdev_dbg = &thermal_dbg->cdev_dbg; + struct list_head *transitions = cdev_dbg->transitions; + struct cdev_record *entry; + int i = *(loff_t *)v; + + if (!i) + seq_puts(s, "Transition\tOccurences\n"); + + list_for_each_entry(entry, &transitions[i], node) { + /* + * Assuming maximum cdev states is 1024, the longer + * string for a transition would be "1024->1024\0" + */ + char buffer[11]; + + snprintf(buffer, ARRAY_SIZE(buffer), "%d->%d", + entry->id >> 16, entry->id & 0xFFFF); + + seq_printf(s, "%-10s\t%-10llu\n", buffer, entry->count); + } + + return 0; +} + +static const struct seq_operations tt_sops = { + .start = cdev_seq_start, + .next = cdev_seq_next, + .stop = cdev_seq_stop, + .show = cdev_tt_seq_show, +}; + +DEFINE_SEQ_ATTRIBUTE(tt); + +static int cdev_dt_seq_show(struct seq_file *s, void *v) +{ + struct thermal_debugfs *thermal_dbg = s->private; + struct cdev_debugfs *cdev_dbg = &thermal_dbg->cdev_dbg; + struct list_head *durations = cdev_dbg->durations; + struct cdev_record *entry; + int i = *(loff_t *)v; + + if (!i) + seq_puts(s, "State\tResidency\n"); + + list_for_each_entry(entry, &durations[i], node) { + s64 duration = ktime_to_ms(entry->residency); + + if (entry->id == cdev_dbg->current_state) + duration += ktime_ms_delta(ktime_get(), + cdev_dbg->timestamp); + + seq_printf(s, "%-5d\t%-10llu\n", entry->id, duration); + } + + return 0; +} + +static const struct seq_operations dt_sops = { + .start = cdev_seq_start, + .next = cdev_seq_next, + .stop = cdev_seq_stop, + .show = cdev_dt_seq_show, +}; + +DEFINE_SEQ_ATTRIBUTE(dt); + +static int cdev_clear_set(void *data, u64 val) +{ + struct thermal_debugfs *thermal_dbg = data; + + if (!val) + return -EINVAL; + + mutex_lock(&thermal_dbg->lock); + + thermal_debugfs_cdev_clear(&thermal_dbg->cdev_dbg); + + mutex_unlock(&thermal_dbg->lock); + + return 0; +} + +DEFINE_DEBUGFS_ATTRIBUTE(cdev_clear_fops, NULL, cdev_clear_set, "%llu\n"); + +/** + * thermal_debug_cdev_state_update - Update a cooling device state change + * + * Computes a transition and the duration of the previous state residency. + * + * @cdev : a pointer to a cooling device + * @new_state: an integer corresponding to the new cooling device state + */ +void thermal_debug_cdev_state_update(const struct thermal_cooling_device *cdev, + int new_state) +{ + struct thermal_debugfs *thermal_dbg = cdev->debugfs; + struct cdev_debugfs *cdev_dbg; + struct cdev_record *cdev_record; + int transition, old_state; + + if (!thermal_dbg || (thermal_dbg->cdev_dbg.current_state == new_state)) + return; + + mutex_lock(&thermal_dbg->lock); + + cdev_dbg = &thermal_dbg->cdev_dbg; + + old_state = cdev_dbg->current_state; + + /* + * Get the old state information in the durations list. If + * this one does not exist, a new allocated one will be + * returned. Recompute the total duration in the old state and + * get a new timestamp for the new state. + */ + cdev_record = thermal_debugfs_cdev_record_get(thermal_dbg, + cdev_dbg->durations, + old_state); + if (cdev_record) { + ktime_t now = ktime_get(); + ktime_t delta = ktime_sub(now, cdev_dbg->timestamp); + cdev_record->residency = ktime_add(cdev_record->residency, delta); + cdev_dbg->timestamp = now; + } + + cdev_dbg->current_state = new_state; + transition = (old_state << 16) | new_state; + + /* + * Get the transition in the transitions list. If this one + * does not exist, a new allocated one will be returned. + * Increment the occurrence of this transition which is stored + * in the value field. + */ + cdev_record = thermal_debugfs_cdev_record_get(thermal_dbg, + cdev_dbg->transitions, + transition); + if (cdev_record) + cdev_record->count++; + + cdev_dbg->total++; + + mutex_unlock(&thermal_dbg->lock); +} + +/** + * thermal_debug_cdev_add - Add a cooling device debugfs entry + * + * Allocates a cooling device object for debug, initializes the + * statistics and create the entries in sysfs. + * @cdev: a pointer to a cooling device + */ +void thermal_debug_cdev_add(struct thermal_cooling_device *cdev) +{ + struct thermal_debugfs *thermal_dbg; + struct cdev_debugfs *cdev_dbg; + int i; + + thermal_dbg = thermal_debugfs_add_id(d_cdev, cdev->id); + if (!thermal_dbg) + return; + + cdev_dbg = &thermal_dbg->cdev_dbg; + + for (i = 0; i < CDEVSTATS_HASH_SIZE; i++) { + INIT_LIST_HEAD(&cdev_dbg->transitions[i]); + INIT_LIST_HEAD(&cdev_dbg->durations[i]); + } + + cdev_dbg->current_state = 0; + cdev_dbg->timestamp = ktime_get(); + + debugfs_create_file("trans_table", 0400, thermal_dbg->d_top, + thermal_dbg, &tt_fops); + + debugfs_create_file("time_in_state_ms", 0400, thermal_dbg->d_top, + thermal_dbg, &dt_fops); + + debugfs_create_file("clear", 0200, thermal_dbg->d_top, + thermal_dbg, &cdev_clear_fops); + + debugfs_create_u32("total_trans", 0400, thermal_dbg->d_top, + &cdev_dbg->total); + + cdev->debugfs = thermal_dbg; +} + +/** + * thermal_debug_cdev_remove - Remove a cooling device debugfs entry + * + * Frees the statistics memory data and remove the debugfs entry + * + * @cdev: a pointer to a cooling device + */ +void thermal_debug_cdev_remove(struct thermal_cooling_device *cdev) +{ + struct thermal_debugfs *thermal_dbg = cdev->debugfs; + + if (!thermal_dbg) + return; + + mutex_lock(&thermal_dbg->lock); + + thermal_debugfs_cdev_clear(&thermal_dbg->cdev_dbg); + cdev->debugfs = NULL; + + mutex_unlock(&thermal_dbg->lock); + + thermal_debugfs_remove_id(thermal_dbg); +} diff --git a/drivers/thermal/thermal_debugfs.h b/drivers/thermal/thermal_debugfs.h new file mode 100644 index 000000000000..341499388448 --- /dev/null +++ b/drivers/thermal/thermal_debugfs.h @@ -0,0 +1,14 @@ +/* SPDX-License-Identifier: GPL-2.0 */ + +#ifdef CONFIG_THERMAL_DEBUGFS +void thermal_debug_init(void); +void thermal_debug_cdev_add(struct thermal_cooling_device *cdev); +void thermal_debug_cdev_remove(struct thermal_cooling_device *cdev); +void thermal_debug_cdev_state_update(const struct thermal_cooling_device *cdev, int state); +#else +static inline void thermal_debug_init(void) {} +static inline void thermal_debug_cdev_add(struct thermal_cooling_device *cdev) {} +static inline void thermal_debug_cdev_remove(struct thermal_cooling_device *cdev) {} +static inline void thermal_debug_cdev_state_update(const struct thermal_cooling_device *cdev, + int state) {} +#endif /* CONFIG_THERMAL_DEBUGFS */ diff --git a/drivers/thermal/thermal_helpers.c b/drivers/thermal/thermal_helpers.c index c3982e0f0075..8f85581693e7 100644 --- a/drivers/thermal/thermal_helpers.c +++ b/drivers/thermal/thermal_helpers.c @@ -146,14 +146,22 @@ unlock: } EXPORT_SYMBOL_GPL(thermal_zone_get_temp); -static void thermal_cdev_set_cur_state(struct thermal_cooling_device *cdev, - int target) +static int thermal_cdev_set_cur_state(struct thermal_cooling_device *cdev, int state) { - if (cdev->ops->set_cur_state(cdev, target)) - return; + int ret; + + /* + * No check is needed for the ops->set_cur_state as the + * registering function checked the ops are correctly set + */ + ret = cdev->ops->set_cur_state(cdev, state); + if (!ret) { + thermal_notify_cdev_state_update(cdev->id, state); + thermal_cooling_device_stats_update(cdev, state); + thermal_debug_cdev_state_update(cdev, state); + } - thermal_notify_cdev_state_update(cdev->id, target); - thermal_cooling_device_stats_update(cdev, target); + return ret; } void __thermal_cdev_update(struct thermal_cooling_device *cdev) diff --git a/include/linux/thermal.h b/include/linux/thermal.h index 9d0427da32af..7defea8fa223 100644 --- a/include/linux/thermal.h +++ b/include/linux/thermal.h @@ -32,6 +32,7 @@ struct thermal_zone_device; struct thermal_cooling_device; struct thermal_instance; +struct thermal_debugfs; struct thermal_attr; enum thermal_trend { @@ -113,6 +114,9 @@ struct thermal_cooling_device { struct mutex lock; /* protect thermal_instances list */ struct list_head thermal_instances; struct list_head node; +#ifdef CONFIG_THERMAL_DEBUGFS + struct thermal_debugfs *debugfs; +#endif }; /** @@ -189,6 +193,9 @@ struct thermal_zone_device { struct list_head node; struct delayed_work poll_queue; enum thermal_notify_event notify_event; +#ifdef CONFIG_THERMAL_DEBUGFS + struct thermal_debugfs *debugfs; +#endif bool suspended; }; |