diff options
| -rw-r--r-- | Documentation/ABI/testing/sysfs-power | 42 | ||||
| -rw-r--r-- | drivers/base/power/wakeup.c | 1 | ||||
| -rw-r--r-- | kernel/power/Kconfig | 8 | ||||
| -rw-r--r-- | kernel/power/Makefile | 1 | ||||
| -rw-r--r-- | kernel/power/main.c | 41 | ||||
| -rw-r--r-- | kernel/power/power.h | 9 | ||||
| -rw-r--r-- | kernel/power/wakelock.c | 215 |
7 files changed, 317 insertions, 0 deletions
diff --git a/Documentation/ABI/testing/sysfs-power b/Documentation/ABI/testing/sysfs-power index 237c735db6c9..31725ffeeb3a 100644 --- a/Documentation/ABI/testing/sysfs-power +++ b/Documentation/ABI/testing/sysfs-power @@ -189,3 +189,45 @@ Description: Reading from this file causes the last string successfully written to it to be returned. + +What: /sys/power/wake_lock +Date: February 2012 +Contact: Rafael J. Wysocki <rjw@sisk.pl> +Description: + The /sys/power/wake_lock file allows user space to create + wakeup source objects and activate them on demand (if one of + those wakeup sources is active, reads from the + /sys/power/wakeup_count file block or return false). When a + string without white space is written to /sys/power/wake_lock, + it will be assumed to represent a wakeup source name. If there + is a wakeup source object with that name, it will be activated + (unless active already). Otherwise, a new wakeup source object + will be registered, assigned the given name and activated. + If a string written to /sys/power/wake_lock contains white + space, the part of the string preceding the white space will be + regarded as a wakeup source name and handled as descrived above. + The other part of the string will be regarded as a timeout (in + nanoseconds) such that the wakeup source will be automatically + deactivated after it has expired. The timeout, if present, is + set regardless of the current state of the wakeup source object + in question. + + Reads from this file return a string consisting of the names of + wakeup sources created with the help of it that are active at + the moment, separated with spaces. + + +What: /sys/power/wake_unlock +Date: February 2012 +Contact: Rafael J. Wysocki <rjw@sisk.pl> +Description: + The /sys/power/wake_unlock file allows user space to deactivate + wakeup sources created with the help of /sys/power/wake_lock. + When a string is written to /sys/power/wake_unlock, it will be + assumed to represent the name of a wakeup source to deactivate. + If a wakeup source object of that name exists and is active at + the moment, it will be deactivated. + + Reads from this file return a string consisting of the names of + wakeup sources created with the help of /sys/power/wake_lock + that are inactive at the moment, separated with spaces. diff --git a/drivers/base/power/wakeup.c b/drivers/base/power/wakeup.c index 2595b8d8fe1f..cbb463b3a750 100644 --- a/drivers/base/power/wakeup.c +++ b/drivers/base/power/wakeup.c @@ -133,6 +133,7 @@ void wakeup_source_add(struct wakeup_source *ws) spin_lock_init(&ws->lock); setup_timer(&ws->timer, pm_wakeup_timer_fn, (unsigned long)ws); ws->active = false; + ws->last_time = ktime_get(); spin_lock_irq(&events_lock); list_add_rcu(&ws->entry, &wakeup_sources); diff --git a/kernel/power/Kconfig b/kernel/power/Kconfig index 67947083f842..1d534076d33a 100644 --- a/kernel/power/Kconfig +++ b/kernel/power/Kconfig @@ -111,6 +111,14 @@ config PM_AUTOSLEEP Allow the kernel to trigger a system transition into a global sleep state automatically whenever there are no active wakeup sources. +config PM_WAKELOCKS + bool "User space wakeup sources interface" + depends on PM_SLEEP + default n + ---help--- + Allow user space to create, activate and deactivate wakeup source + objects with the help of a sysfs-based interface. + config PM_RUNTIME bool "Run-time PM core functionality" depends on !IA64_HP_SIM diff --git a/kernel/power/Makefile b/kernel/power/Makefile index 010b2f7e148c..29472bff11ef 100644 --- a/kernel/power/Makefile +++ b/kernel/power/Makefile @@ -10,5 +10,6 @@ obj-$(CONFIG_PM_TEST_SUSPEND) += suspend_test.o obj-$(CONFIG_HIBERNATION) += hibernate.o snapshot.o swap.o user.o \ block_io.o obj-$(CONFIG_PM_AUTOSLEEP) += autosleep.o +obj-$(CONFIG_PM_WAKELOCKS) += wakelock.o obj-$(CONFIG_MAGIC_SYSRQ) += poweroff.o diff --git a/kernel/power/main.c b/kernel/power/main.c index ba6a5645952d..54ec071de337 100644 --- a/kernel/power/main.c +++ b/kernel/power/main.c @@ -431,6 +431,43 @@ static ssize_t autosleep_store(struct kobject *kobj, power_attr(autosleep); #endif /* CONFIG_PM_AUTOSLEEP */ + +#ifdef CONFIG_PM_WAKELOCKS +static ssize_t wake_lock_show(struct kobject *kobj, + struct kobj_attribute *attr, + char *buf) +{ + return pm_show_wakelocks(buf, true); +} + +static ssize_t wake_lock_store(struct kobject *kobj, + struct kobj_attribute *attr, + const char *buf, size_t n) +{ + int error = pm_wake_lock(buf); + return error ? error : n; +} + +power_attr(wake_lock); + +static ssize_t wake_unlock_show(struct kobject *kobj, + struct kobj_attribute *attr, + char *buf) +{ + return pm_show_wakelocks(buf, false); +} + +static ssize_t wake_unlock_store(struct kobject *kobj, + struct kobj_attribute *attr, + const char *buf, size_t n) +{ + int error = pm_wake_unlock(buf); + return error ? error : n; +} + +power_attr(wake_unlock); + +#endif /* CONFIG_PM_WAKELOCKS */ #endif /* CONFIG_PM_SLEEP */ #ifdef CONFIG_PM_TRACE @@ -487,6 +524,10 @@ static struct attribute * g[] = { #ifdef CONFIG_PM_AUTOSLEEP &autosleep_attr.attr, #endif +#ifdef CONFIG_PM_WAKELOCKS + &wake_lock_attr.attr, + &wake_unlock_attr.attr, +#endif #ifdef CONFIG_PM_DEBUG &pm_test_attr.attr, #endif diff --git a/kernel/power/power.h b/kernel/power/power.h index 4cf80fa115d9..b0bd4beaebfe 100644 --- a/kernel/power/power.h +++ b/kernel/power/power.h @@ -282,3 +282,12 @@ static inline void pm_autosleep_unlock(void) {} static inline suspend_state_t pm_autosleep_state(void) { return PM_SUSPEND_ON; } #endif /* !CONFIG_PM_AUTOSLEEP */ + +#ifdef CONFIG_PM_WAKELOCKS + +/* kernel/power/wakelock.c */ +extern ssize_t pm_show_wakelocks(char *buf, bool show_active); +extern int pm_wake_lock(const char *buf); +extern int pm_wake_unlock(const char *buf); + +#endif /* !CONFIG_PM_WAKELOCKS */ diff --git a/kernel/power/wakelock.c b/kernel/power/wakelock.c new file mode 100644 index 000000000000..579700665e8c --- /dev/null +++ b/kernel/power/wakelock.c @@ -0,0 +1,215 @@ +/* + * kernel/power/wakelock.c + * + * User space wakeup sources support. + * + * Copyright (C) 2012 Rafael J. Wysocki <rjw@sisk.pl> + * + * This code is based on the analogous interface allowing user space to + * manipulate wakelocks on Android. + */ + +#include <linux/ctype.h> +#include <linux/device.h> +#include <linux/err.h> +#include <linux/hrtimer.h> +#include <linux/list.h> +#include <linux/rbtree.h> +#include <linux/slab.h> + +#define WL_NUMBER_LIMIT 100 +#define WL_GC_COUNT_MAX 100 +#define WL_GC_TIME_SEC 300 + +static DEFINE_MUTEX(wakelocks_lock); + +struct wakelock { + char *name; + struct rb_node node; + struct wakeup_source ws; + struct list_head lru; +}; + +static struct rb_root wakelocks_tree = RB_ROOT; +static LIST_HEAD(wakelocks_lru_list); +static unsigned int number_of_wakelocks; +static unsigned int wakelocks_gc_count; + +ssize_t pm_show_wakelocks(char *buf, bool show_active) +{ + struct rb_node *node; + struct wakelock *wl; + char *str = buf; + char *end = buf + PAGE_SIZE; + + mutex_lock(&wakelocks_lock); + + for (node = rb_first(&wakelocks_tree); node; node = rb_next(node)) { + wl = rb_entry(node, struct wakelock, node); + if (wl->ws.active == show_active) + str += scnprintf(str, end - str, "%s ", wl->name); + } + if (str > buf) + str--; + + str += scnprintf(str, end - str, "\n"); + + mutex_unlock(&wakelocks_lock); + return (str - buf); +} + +static struct wakelock *wakelock_lookup_add(const char *name, size_t len, + bool add_if_not_found) +{ + struct rb_node **node = &wakelocks_tree.rb_node; + struct rb_node *parent = *node; + struct wakelock *wl; + + while (*node) { + int diff; + + parent = *node; + wl = rb_entry(*node, struct wakelock, node); + diff = strncmp(name, wl->name, len); + if (diff == 0) { + if (wl->name[len]) + diff = -1; + else + return wl; + } + if (diff < 0) + node = &(*node)->rb_left; + else + node = &(*node)->rb_right; + } + if (!add_if_not_found) + return ERR_PTR(-EINVAL); + + if (number_of_wakelocks > WL_NUMBER_LIMIT) + return ERR_PTR(-ENOSPC); + + /* Not found, we have to add a new one. */ + wl = kzalloc(sizeof(*wl), GFP_KERNEL); + if (!wl) + return ERR_PTR(-ENOMEM); + + wl->name = kstrndup(name, len, GFP_KERNEL); + if (!wl->name) { + kfree(wl); + return ERR_PTR(-ENOMEM); + } + wl->ws.name = wl->name; + wakeup_source_add(&wl->ws); + rb_link_node(&wl->node, parent, node); + rb_insert_color(&wl->node, &wakelocks_tree); + list_add(&wl->lru, &wakelocks_lru_list); + number_of_wakelocks++; + return wl; +} + +int pm_wake_lock(const char *buf) +{ + const char *str = buf; + struct wakelock *wl; + u64 timeout_ns = 0; + size_t len; + int ret = 0; + + while (*str && !isspace(*str)) + str++; + + len = str - buf; + if (!len) + return -EINVAL; + + if (*str && *str != '\n') { + /* Find out if there's a valid timeout string appended. */ + ret = kstrtou64(skip_spaces(str), 10, &timeout_ns); + if (ret) + return -EINVAL; + } + + mutex_lock(&wakelocks_lock); + + wl = wakelock_lookup_add(buf, len, true); + if (IS_ERR(wl)) { + ret = PTR_ERR(wl); + goto out; + } + if (timeout_ns) { + u64 timeout_ms = timeout_ns + NSEC_PER_MSEC - 1; + + do_div(timeout_ms, NSEC_PER_MSEC); + __pm_wakeup_event(&wl->ws, timeout_ms); + } else { + __pm_stay_awake(&wl->ws); + } + + list_move(&wl->lru, &wakelocks_lru_list); + + out: + mutex_unlock(&wakelocks_lock); + return ret; +} + +static void wakelocks_gc(void) +{ + struct wakelock *wl, *aux; + ktime_t now = ktime_get(); + + list_for_each_entry_safe_reverse(wl, aux, &wakelocks_lru_list, lru) { + u64 idle_time_ns; + bool active; + + spin_lock_irq(&wl->ws.lock); + idle_time_ns = ktime_to_ns(ktime_sub(now, wl->ws.last_time)); + active = wl->ws.active; + spin_unlock_irq(&wl->ws.lock); + + if (idle_time_ns < ((u64)WL_GC_TIME_SEC * NSEC_PER_SEC)) + break; + + if (!active) { + wakeup_source_remove(&wl->ws); + rb_erase(&wl->node, &wakelocks_tree); + list_del(&wl->lru); + kfree(wl->name); + kfree(wl); + number_of_wakelocks--; + } + } + wakelocks_gc_count = 0; +} + +int pm_wake_unlock(const char *buf) +{ + struct wakelock *wl; + size_t len; + int ret = 0; + + len = strlen(buf); + if (!len) + return -EINVAL; + + if (buf[len-1] == '\n') + len--; + + if (!len) + return -EINVAL; + + mutex_lock(&wakelocks_lock); + + wl = wakelock_lookup_add(buf, len, false); + if (IS_ERR(wl)) { + ret = PTR_ERR(wl); + goto out; + } + __pm_relax(&wl->ws); + list_move(&wl->lru, &wakelocks_lru_list); + if (++wakelocks_gc_count > WL_GC_COUNT_MAX) + wakelocks_gc(); + + out: + mutex_unlock(&wakelocks_lock); + return ret; +} |