[GitHub/mt8127/android_kernel_alcatel_ttab.git] / kernel / power / wakelock.c

/*
 * 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/capability.h>
#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>

static DEFINE_MUTEX(wakelocks_lock);

struct wakelock {
	char			*name;
	struct rb_node		node;
	struct wakeup_source	ws;
#ifdef CONFIG_PM_WAKELOCKS_GC
	struct list_head	lru;
#endif
};

static struct rb_root wakelocks_tree = RB_ROOT;

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);
}

#if CONFIG_PM_WAKELOCKS_LIMIT > 0
static unsigned int number_of_wakelocks;

static inline bool wakelocks_limit_exceeded(void)
{
	return number_of_wakelocks > CONFIG_PM_WAKELOCKS_LIMIT;
}

static inline void increment_wakelocks_number(void)
{
	number_of_wakelocks++;
}

static inline void decrement_wakelocks_number(void)
{
	number_of_wakelocks--;
}
#else /* CONFIG_PM_WAKELOCKS_LIMIT = 0 */
static inline bool wakelocks_limit_exceeded(void) { return false; }
static inline void increment_wakelocks_number(void) {}
static inline void decrement_wakelocks_number(void) {}
#endif /* CONFIG_PM_WAKELOCKS_LIMIT */

#ifdef CONFIG_PM_WAKELOCKS_GC
#define WL_GC_COUNT_MAX	100
#define WL_GC_TIME_SEC	300

static LIST_HEAD(wakelocks_lru_list);
static unsigned int wakelocks_gc_count;

static inline void wakelocks_lru_add(struct wakelock *wl)
{
	list_add(&wl->lru, &wakelocks_lru_list);
}

static inline void wakelocks_lru_most_recent(struct wakelock *wl)
{
	list_move(&wl->lru, &wakelocks_lru_list);
}

static void wakelocks_gc(void)
{
	struct wakelock *wl, *aux;
	ktime_t now;

	if (++wakelocks_gc_count <= WL_GC_COUNT_MAX)
		return;

	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);
			decrement_wakelocks_number();
		}
	}
	wakelocks_gc_count = 0;
}
#else /* !CONFIG_PM_WAKELOCKS_GC */
static inline void wakelocks_lru_add(struct wakelock *wl) {}
static inline void wakelocks_lru_most_recent(struct wakelock *wl) {}
static inline void wakelocks_gc(void) {}
#endif /* !CONFIG_PM_WAKELOCKS_GC */

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 (wakelocks_limit_exceeded())
		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);
	wakelocks_lru_add(wl);
	increment_wakelocks_number();
	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;

	if (!capable(CAP_BLOCK_SUSPEND))
		return -EPERM;

	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);
	}

	wakelocks_lru_most_recent(wl);

 out:
	mutex_unlock(&wakelocks_lock);
	return ret;
}

int pm_wake_unlock(const char *buf)
{
	struct wakelock *wl;
	size_t len;
	int ret = 0;

	if (!capable(CAP_BLOCK_SUSPEND))
		return -EPERM;

	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);

	wakelocks_lru_most_recent(wl);
	wakelocks_gc();

 out:
	mutex_unlock(&wakelocks_lock);
	return ret;
}
Commit	Line	Data
b86ff982 RW	1	/*
	2	* kernel/power/wakelock.c
	3	*
	4	* User space wakeup sources support.
	5	*
	6	* Copyright (C) 2012 Rafael J. Wysocki <rjw@sisk.pl>
	7	*
	8	* This code is based on the analogous interface allowing user space to
	9	* manipulate wakelocks on Android.
	10	*/
	11
11388c87	12	#include <linux/capability.h>
b86ff982 RW	13	#include <linux/ctype.h>
	14	#include <linux/device.h>
	15	#include <linux/err.h>
	16	#include <linux/hrtimer.h>
	17	#include <linux/list.h>
	18	#include <linux/rbtree.h>
	19	#include <linux/slab.h>
	20
b86ff982 RW	21	static DEFINE_MUTEX(wakelocks_lock);
	22
	23	struct wakelock {
	24	char *name;
	25	struct rb_node node;
	26	struct wakeup_source ws;
4e585d25	27	#ifdef CONFIG_PM_WAKELOCKS_GC
b86ff982	28	struct list_head lru;
4e585d25	29	#endif
b86ff982 RW	30	};
	31
	32	static struct rb_root wakelocks_tree = RB_ROOT;
b86ff982 RW	33
	34	ssize_t pm_show_wakelocks(char *buf, bool show_active)
	35	{
	36	struct rb_node *node;
	37	struct wakelock *wl;
	38	char *str = buf;
	39	char *end = buf + PAGE_SIZE;
	40
	41	mutex_lock(&wakelocks_lock);
	42
	43	for (node = rb_first(&wakelocks_tree); node; node = rb_next(node)) {
	44	wl = rb_entry(node, struct wakelock, node);
	45	if (wl->ws.active == show_active)
	46	str += scnprintf(str, end - str, "%s ", wl->name);
	47	}
	48	if (str > buf)
	49	str--;
	50
	51	str += scnprintf(str, end - str, "\n");
	52
	53	mutex_unlock(&wakelocks_lock);
	54	return (str - buf);
	55	}
	56
c73893e2 RW	57	#if CONFIG_PM_WAKELOCKS_LIMIT > 0
	58	static unsigned int number_of_wakelocks;
	59
	60	static inline bool wakelocks_limit_exceeded(void)
	61	{
	62	return number_of_wakelocks > CONFIG_PM_WAKELOCKS_LIMIT;
	63	}
	64
	65	static inline void increment_wakelocks_number(void)
	66	{
	67	number_of_wakelocks++;
	68	}
	69
	70	static inline void decrement_wakelocks_number(void)
	71	{
	72	number_of_wakelocks--;
	73	}
	74	#else /* CONFIG_PM_WAKELOCKS_LIMIT = 0 */
	75	static inline bool wakelocks_limit_exceeded(void) { return false; }
	76	static inline void increment_wakelocks_number(void) {}
	77	static inline void decrement_wakelocks_number(void) {}
	78	#endif /* CONFIG_PM_WAKELOCKS_LIMIT */
	79
4e585d25 RW	80	#ifdef CONFIG_PM_WAKELOCKS_GC
	81	#define WL_GC_COUNT_MAX 100
	82	#define WL_GC_TIME_SEC 300
	83
	84	static LIST_HEAD(wakelocks_lru_list);
	85	static unsigned int wakelocks_gc_count;
	86
	87	static inline void wakelocks_lru_add(struct wakelock *wl)
	88	{
	89	list_add(&wl->lru, &wakelocks_lru_list);
	90	}
	91
	92	static inline void wakelocks_lru_most_recent(struct wakelock *wl)
	93	{
	94	list_move(&wl->lru, &wakelocks_lru_list);
	95	}
	96
	97	static void wakelocks_gc(void)
	98	{
	99	struct wakelock wl, aux;
	100	ktime_t now;
	101
	102	if (++wakelocks_gc_count <= WL_GC_COUNT_MAX)
	103	return;
	104
	105	now = ktime_get();
	106	list_for_each_entry_safe_reverse(wl, aux, &wakelocks_lru_list, lru) {
	107	u64 idle_time_ns;
	108	bool active;
	109
	110	spin_lock_irq(&wl->ws.lock);
	111	idle_time_ns = ktime_to_ns(ktime_sub(now, wl->ws.last_time));
	112	active = wl->ws.active;
	113	spin_unlock_irq(&wl->ws.lock);
	114
	115	if (idle_time_ns < ((u64)WL_GC_TIME_SEC * NSEC_PER_SEC))
	116	break;
	117
	118	if (!active) {
	119	wakeup_source_remove(&wl->ws);
	120	rb_erase(&wl->node, &wakelocks_tree);
	121	list_del(&wl->lru);
	122	kfree(wl->name);
	123	kfree(wl);
	124	decrement_wakelocks_number();
	125	}
	126	}
	127	wakelocks_gc_count = 0;
	128	}
	129	#else /* !CONFIG_PM_WAKELOCKS_GC */
	130	static inline void wakelocks_lru_add(struct wakelock *wl) {}
	131	static inline void wakelocks_lru_most_recent(struct wakelock *wl) {}
	132	static inline void wakelocks_gc(void) {}
	133	#endif /* !CONFIG_PM_WAKELOCKS_GC */
	134
b86ff982 RW	135	static struct wakelock wakelock_lookup_add(const char name, size_t len,
	136	bool add_if_not_found)
	137	{
	138	struct rb_node **node = &wakelocks_tree.rb_node;
	139	struct rb_node parent = node;
	140	struct wakelock *wl;
	141
	142	while (*node) {
	143	int diff;
	144
	145	parent = *node;
	146	wl = rb_entry(*node, struct wakelock, node);
	147	diff = strncmp(name, wl->name, len);
	148	if (diff == 0) {
	149	if (wl->name[len])
	150	diff = -1;
	151	else
	152	return wl;
	153	}
	154	if (diff < 0)
	155	node = &(*node)->rb_left;
	156	else
	157	node = &(*node)->rb_right;
	158	}
	159	if (!add_if_not_found)
	160	return ERR_PTR(-EINVAL);
	161
c73893e2	162	if (wakelocks_limit_exceeded())
b86ff982 RW	163	return ERR_PTR(-ENOSPC);
	164
	165	/* Not found, we have to add a new one. */
	166	wl = kzalloc(sizeof(*wl), GFP_KERNEL);
	167	if (!wl)
	168	return ERR_PTR(-ENOMEM);
	169
	170	wl->name = kstrndup(name, len, GFP_KERNEL);
	171	if (!wl->name) {
	172	kfree(wl);
	173	return ERR_PTR(-ENOMEM);
	174	}
	175	wl->ws.name = wl->name;
	176	wakeup_source_add(&wl->ws);
	177	rb_link_node(&wl->node, parent, node);
	178	rb_insert_color(&wl->node, &wakelocks_tree);
4e585d25	179	wakelocks_lru_add(wl);
c73893e2	180	increment_wakelocks_number();
b86ff982 RW	181	return wl;
	182	}
	183
	184	int pm_wake_lock(const char *buf)
	185	{
	186	const char *str = buf;
	187	struct wakelock *wl;
	188	u64 timeout_ns = 0;
	189	size_t len;
	190	int ret = 0;
	191
11388c87 RW	192	if (!capable(CAP_BLOCK_SUSPEND))
	193	return -EPERM;
	194
b86ff982 RW	195	while (str && !isspace(str))
	196	str++;
	197
	198	len = str - buf;
	199	if (!len)
	200	return -EINVAL;
	201
	202	if (str && str != '\n') {
	203	/* Find out if there's a valid timeout string appended. */
	204	ret = kstrtou64(skip_spaces(str), 10, &timeout_ns);
	205	if (ret)
	206	return -EINVAL;
	207	}
	208
	209	mutex_lock(&wakelocks_lock);
	210
	211	wl = wakelock_lookup_add(buf, len, true);
	212	if (IS_ERR(wl)) {
	213	ret = PTR_ERR(wl);
	214	goto out;
	215	}
	216	if (timeout_ns) {
	217	u64 timeout_ms = timeout_ns + NSEC_PER_MSEC - 1;
	218
	219	do_div(timeout_ms, NSEC_PER_MSEC);
	220	__pm_wakeup_event(&wl->ws, timeout_ms);
	221	} else {
	222	__pm_stay_awake(&wl->ws);
	223	}
	224
4e585d25	225	wakelocks_lru_most_recent(wl);
b86ff982 RW	226
	227	out:
	228	mutex_unlock(&wakelocks_lock);
	229	return ret;
	230	}
	231
b86ff982 RW	232	int pm_wake_unlock(const char *buf)
	233	{
	234	struct wakelock *wl;
	235	size_t len;
	236	int ret = 0;
	237
11388c87 RW	238	if (!capable(CAP_BLOCK_SUSPEND))
	239	return -EPERM;
	240
b86ff982 RW	241	len = strlen(buf);
	242	if (!len)
	243	return -EINVAL;
	244
	245	if (buf[len-1] == '\n')
	246	len--;
	247
	248	if (!len)
	249	return -EINVAL;
	250
	251	mutex_lock(&wakelocks_lock);
	252
	253	wl = wakelock_lookup_add(buf, len, false);
	254	if (IS_ERR(wl)) {
	255	ret = PTR_ERR(wl);
	256	goto out;
	257	}
	258	__pm_relax(&wl->ws);
4e585d25 RW	259
	260	wakelocks_lru_most_recent(wl);
	261	wakelocks_gc();
b86ff982 RW	262
	263	out:
	264	mutex_unlock(&wakelocks_lock);
	265	return ret;
	266	}