diff options
Diffstat (limited to 'kernel/power/userwakelock.c')
| -rw-r--r-- | kernel/power/userwakelock.c | 219 |
1 files changed, 219 insertions, 0 deletions
diff --git a/kernel/power/userwakelock.c b/kernel/power/userwakelock.c new file mode 100644 index 000000000000..a28a8db41468 --- /dev/null +++ b/kernel/power/userwakelock.c @@ -0,0 +1,219 @@ +/* kernel/power/userwakelock.c + * + * Copyright (C) 2005-2008 Google, Inc. + * + * This software is licensed under the terms of the GNU General Public + * License version 2, as published by the Free Software Foundation, and + * may be copied, distributed, and modified under those terms. + * + * This program is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + * GNU General Public License for more details. + * + */ + +#include <linux/ctype.h> +#include <linux/module.h> +#include <linux/wakelock.h> +#include <linux/slab.h> + +#include "power.h" + +enum { + DEBUG_FAILURE = BIT(0), + DEBUG_ERROR = BIT(1), + DEBUG_NEW = BIT(2), + DEBUG_ACCESS = BIT(3), + DEBUG_LOOKUP = BIT(4), +}; +static int debug_mask = DEBUG_FAILURE; +module_param_named(debug_mask, debug_mask, int, S_IRUGO | S_IWUSR | S_IWGRP); + +static DEFINE_MUTEX(tree_lock); + +struct user_wake_lock { + struct rb_node node; + struct wake_lock wake_lock; + char name[0]; +}; +struct rb_root user_wake_locks; + +static struct user_wake_lock *lookup_wake_lock_name( + const char *buf, int allocate, long *timeoutptr) +{ + struct rb_node **p = &user_wake_locks.rb_node; + struct rb_node *parent = NULL; + struct user_wake_lock *l; + int diff; + u64 timeout; + int name_len; + const char *arg; + + /* Find length of lock name and start of optional timeout string */ + arg = buf; + while (*arg && !isspace(*arg)) + arg++; + name_len = arg - buf; + if (!name_len) + goto bad_arg; + while (isspace(*arg)) + arg++; + + /* Process timeout string */ + if (timeoutptr && *arg) { + timeout = simple_strtoull(arg, (char **)&arg, 0); + while (isspace(*arg)) + arg++; + if (*arg) + goto bad_arg; + /* convert timeout from nanoseconds to jiffies > 0 */ + timeout += (NSEC_PER_SEC / HZ) - 1; + do_div(timeout, (NSEC_PER_SEC / HZ)); + if (timeout <= 0) + timeout = 1; + *timeoutptr = timeout; + } else if (*arg) + goto bad_arg; + else if (timeoutptr) + *timeoutptr = 0; + + /* Lookup wake lock in rbtree */ + while (*p) { + parent = *p; + l = rb_entry(parent, struct user_wake_lock, node); + diff = strncmp(buf, l->name, name_len); + if (!diff && l->name[name_len]) + diff = -1; + if (debug_mask & DEBUG_ERROR) + pr_info("lookup_wake_lock_name: compare %.*s %s %d\n", + name_len, buf, l->name, diff); + + if (diff < 0) + p = &(*p)->rb_left; + else if (diff > 0) + p = &(*p)->rb_right; + else + return l; + } + + /* Allocate and add new wakelock to rbtree */ + if (!allocate) { + if (debug_mask & DEBUG_ERROR) + pr_info("lookup_wake_lock_name: %.*s not found\n", + name_len, buf); + return ERR_PTR(-EINVAL); + } + l = kzalloc(sizeof(*l) + name_len + 1, GFP_KERNEL); + if (l == NULL) { + if (debug_mask & DEBUG_FAILURE) + pr_err("lookup_wake_lock_name: failed to allocate " + "memory for %.*s\n", name_len, buf); + return ERR_PTR(-ENOMEM); + } + memcpy(l->name, buf, name_len); + if (debug_mask & DEBUG_NEW) + pr_info("lookup_wake_lock_name: new wake lock %s\n", l->name); + wake_lock_init(&l->wake_lock, WAKE_LOCK_SUSPEND, l->name); + rb_link_node(&l->node, parent, p); + rb_insert_color(&l->node, &user_wake_locks); + return l; + +bad_arg: + if (debug_mask & DEBUG_ERROR) + pr_info("lookup_wake_lock_name: wake lock, %.*s, bad arg, %s\n", + name_len, buf, arg); + return ERR_PTR(-EINVAL); +} + +ssize_t wake_lock_show( + struct kobject *kobj, struct kobj_attribute *attr, char *buf) +{ + char *s = buf; + char *end = buf + PAGE_SIZE; + struct rb_node *n; + struct user_wake_lock *l; + + mutex_lock(&tree_lock); + + for (n = rb_first(&user_wake_locks); n != NULL; n = rb_next(n)) { + l = rb_entry(n, struct user_wake_lock, node); + if (wake_lock_active(&l->wake_lock)) + s += scnprintf(s, end - s, "%s ", l->name); + } + s += scnprintf(s, end - s, "\n"); + + mutex_unlock(&tree_lock); + return (s - buf); +} + +ssize_t wake_lock_store( + struct kobject *kobj, struct kobj_attribute *attr, + const char *buf, size_t n) +{ + long timeout; + struct user_wake_lock *l; + + mutex_lock(&tree_lock); + l = lookup_wake_lock_name(buf, 1, &timeout); + if (IS_ERR(l)) { + n = PTR_ERR(l); + goto bad_name; + } + + if (debug_mask & DEBUG_ACCESS) + pr_info("wake_lock_store: %s, timeout %ld\n", l->name, timeout); + + if (timeout) + wake_lock_timeout(&l->wake_lock, timeout); + else + wake_lock(&l->wake_lock); +bad_name: + mutex_unlock(&tree_lock); + return n; +} + + +ssize_t wake_unlock_show( + struct kobject *kobj, struct kobj_attribute *attr, char *buf) +{ + char *s = buf; + char *end = buf + PAGE_SIZE; + struct rb_node *n; + struct user_wake_lock *l; + + mutex_lock(&tree_lock); + + for (n = rb_first(&user_wake_locks); n != NULL; n = rb_next(n)) { + l = rb_entry(n, struct user_wake_lock, node); + if (!wake_lock_active(&l->wake_lock)) + s += scnprintf(s, end - s, "%s ", l->name); + } + s += scnprintf(s, end - s, "\n"); + + mutex_unlock(&tree_lock); + return (s - buf); +} + +ssize_t wake_unlock_store( + struct kobject *kobj, struct kobj_attribute *attr, + const char *buf, size_t n) +{ + struct user_wake_lock *l; + + mutex_lock(&tree_lock); + l = lookup_wake_lock_name(buf, 0, NULL); + if (IS_ERR(l)) { + n = PTR_ERR(l); + goto not_found; + } + + if (debug_mask & DEBUG_ACCESS) + pr_info("wake_unlock_store: %s\n", l->name); + + wake_unlock(&l->wake_lock); +not_found: + mutex_unlock(&tree_lock); + return n; +} + |