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288 lines
5.9 KiB
288 lines
5.9 KiB
// SPDX-License-Identifier: GPL-2.0 |
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/* |
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* kernel/power/wakelock.c |
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* |
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* User space wakeup sources support. |
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* |
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* Copyright (C) 2012 Rafael J. Wysocki <[email protected]> |
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* |
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* This code is based on the analogous interface allowing user space to |
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* manipulate wakelocks on Android. |
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*/ |
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#include <linux/capability.h> |
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#include <linux/ctype.h> |
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#include <linux/device.h> |
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#include <linux/err.h> |
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#include <linux/hrtimer.h> |
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#include <linux/list.h> |
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#include <linux/rbtree.h> |
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#include <linux/slab.h> |
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#include <linux/workqueue.h> |
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#include "power.h" |
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static DEFINE_MUTEX(wakelocks_lock); |
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struct wakelock { |
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char *name; |
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struct rb_node node; |
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struct wakeup_source *ws; |
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#ifdef CONFIG_PM_WAKELOCKS_GC |
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struct list_head lru; |
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#endif |
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}; |
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static struct rb_root wakelocks_tree = RB_ROOT; |
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ssize_t pm_show_wakelocks(char *buf, bool show_active) |
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{ |
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struct rb_node *node; |
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struct wakelock *wl; |
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char *str = buf; |
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char *end = buf + PAGE_SIZE; |
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mutex_lock(&wakelocks_lock); |
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for (node = rb_first(&wakelocks_tree); node; node = rb_next(node)) { |
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wl = rb_entry(node, struct wakelock, node); |
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if (wl->ws->active == show_active) |
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str += scnprintf(str, end - str, "%s ", wl->name); |
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} |
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if (str > buf) |
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str--; |
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str += scnprintf(str, end - str, "\n"); |
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mutex_unlock(&wakelocks_lock); |
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return (str - buf); |
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} |
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#if CONFIG_PM_WAKELOCKS_LIMIT > 0 |
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static unsigned int number_of_wakelocks; |
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static inline bool wakelocks_limit_exceeded(void) |
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{ |
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return number_of_wakelocks > CONFIG_PM_WAKELOCKS_LIMIT; |
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} |
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static inline void increment_wakelocks_number(void) |
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{ |
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number_of_wakelocks++; |
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} |
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static inline void decrement_wakelocks_number(void) |
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{ |
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number_of_wakelocks--; |
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} |
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#else /* CONFIG_PM_WAKELOCKS_LIMIT = 0 */ |
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static inline bool wakelocks_limit_exceeded(void) { return false; } |
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static inline void increment_wakelocks_number(void) {} |
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static inline void decrement_wakelocks_number(void) {} |
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#endif /* CONFIG_PM_WAKELOCKS_LIMIT */ |
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#ifdef CONFIG_PM_WAKELOCKS_GC |
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#define WL_GC_COUNT_MAX 100 |
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#define WL_GC_TIME_SEC 300 |
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static void __wakelocks_gc(struct work_struct *work); |
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static LIST_HEAD(wakelocks_lru_list); |
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static DECLARE_WORK(wakelock_work, __wakelocks_gc); |
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static unsigned int wakelocks_gc_count; |
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static inline void wakelocks_lru_add(struct wakelock *wl) |
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{ |
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list_add(&wl->lru, &wakelocks_lru_list); |
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} |
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static inline void wakelocks_lru_most_recent(struct wakelock *wl) |
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{ |
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list_move(&wl->lru, &wakelocks_lru_list); |
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} |
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static void __wakelocks_gc(struct work_struct *work) |
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{ |
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struct wakelock *wl, *aux; |
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ktime_t now; |
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mutex_lock(&wakelocks_lock); |
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now = ktime_get(); |
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list_for_each_entry_safe_reverse(wl, aux, &wakelocks_lru_list, lru) { |
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u64 idle_time_ns; |
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bool active; |
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spin_lock_irq(&wl->ws->lock); |
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idle_time_ns = ktime_to_ns(ktime_sub(now, wl->ws->last_time)); |
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active = wl->ws->active; |
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spin_unlock_irq(&wl->ws->lock); |
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if (idle_time_ns < ((u64)WL_GC_TIME_SEC * NSEC_PER_SEC)) |
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break; |
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if (!active) { |
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wakeup_source_unregister(wl->ws); |
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rb_erase(&wl->node, &wakelocks_tree); |
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list_del(&wl->lru); |
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kfree(wl->name); |
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kfree(wl); |
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decrement_wakelocks_number(); |
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} |
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} |
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wakelocks_gc_count = 0; |
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mutex_unlock(&wakelocks_lock); |
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} |
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static void wakelocks_gc(void) |
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{ |
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if (++wakelocks_gc_count <= WL_GC_COUNT_MAX) |
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return; |
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schedule_work(&wakelock_work); |
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} |
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#else /* !CONFIG_PM_WAKELOCKS_GC */ |
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static inline void wakelocks_lru_add(struct wakelock *wl) {} |
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static inline void wakelocks_lru_most_recent(struct wakelock *wl) {} |
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static inline void wakelocks_gc(void) {} |
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#endif /* !CONFIG_PM_WAKELOCKS_GC */ |
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static struct wakelock *wakelock_lookup_add(const char *name, size_t len, |
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bool add_if_not_found) |
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{ |
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struct rb_node **node = &wakelocks_tree.rb_node; |
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struct rb_node *parent = *node; |
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struct wakelock *wl; |
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while (*node) { |
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int diff; |
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parent = *node; |
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wl = rb_entry(*node, struct wakelock, node); |
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diff = strncmp(name, wl->name, len); |
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if (diff == 0) { |
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if (wl->name[len]) |
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diff = -1; |
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else |
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return wl; |
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} |
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if (diff < 0) |
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node = &(*node)->rb_left; |
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else |
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node = &(*node)->rb_right; |
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} |
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if (!add_if_not_found) |
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return ERR_PTR(-EINVAL); |
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if (wakelocks_limit_exceeded()) |
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return ERR_PTR(-ENOSPC); |
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/* Not found, we have to add a new one. */ |
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wl = kzalloc(sizeof(*wl), GFP_KERNEL); |
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if (!wl) |
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return ERR_PTR(-ENOMEM); |
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wl->name = kstrndup(name, len, GFP_KERNEL); |
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if (!wl->name) { |
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kfree(wl); |
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return ERR_PTR(-ENOMEM); |
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} |
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wl->ws = wakeup_source_register(NULL, wl->name); |
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if (!wl->ws) { |
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kfree(wl->name); |
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kfree(wl); |
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return ERR_PTR(-ENOMEM); |
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} |
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wl->ws->last_time = ktime_get(); |
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rb_link_node(&wl->node, parent, node); |
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rb_insert_color(&wl->node, &wakelocks_tree); |
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wakelocks_lru_add(wl); |
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increment_wakelocks_number(); |
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return wl; |
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} |
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int pm_wake_lock(const char *buf) |
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{ |
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const char *str = buf; |
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struct wakelock *wl; |
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u64 timeout_ns = 0; |
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size_t len; |
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int ret = 0; |
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if (!capable(CAP_BLOCK_SUSPEND)) |
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return -EPERM; |
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while (*str && !isspace(*str)) |
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str++; |
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len = str - buf; |
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if (!len) |
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return -EINVAL; |
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if (*str && *str != '\n') { |
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/* Find out if there's a valid timeout string appended. */ |
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ret = kstrtou64(skip_spaces(str), 10, &timeout_ns); |
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if (ret) |
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return -EINVAL; |
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} |
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mutex_lock(&wakelocks_lock); |
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wl = wakelock_lookup_add(buf, len, true); |
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if (IS_ERR(wl)) { |
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ret = PTR_ERR(wl); |
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goto out; |
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} |
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if (timeout_ns) { |
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u64 timeout_ms = timeout_ns + NSEC_PER_MSEC - 1; |
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do_div(timeout_ms, NSEC_PER_MSEC); |
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__pm_wakeup_event(wl->ws, timeout_ms); |
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} else { |
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__pm_stay_awake(wl->ws); |
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} |
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wakelocks_lru_most_recent(wl); |
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out: |
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mutex_unlock(&wakelocks_lock); |
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return ret; |
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} |
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int pm_wake_unlock(const char *buf) |
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{ |
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struct wakelock *wl; |
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size_t len; |
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int ret = 0; |
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if (!capable(CAP_BLOCK_SUSPEND)) |
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return -EPERM; |
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len = strlen(buf); |
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if (!len) |
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return -EINVAL; |
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if (buf[len-1] == '\n') |
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len--; |
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if (!len) |
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return -EINVAL; |
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mutex_lock(&wakelocks_lock); |
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wl = wakelock_lookup_add(buf, len, false); |
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if (IS_ERR(wl)) { |
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ret = PTR_ERR(wl); |
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goto out; |
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} |
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__pm_relax(wl->ws); |
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wakelocks_lru_most_recent(wl); |
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wakelocks_gc(); |
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out: |
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mutex_unlock(&wakelocks_lock); |
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return ret; |
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}
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