-/* 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 "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;
-}
-
projects / firefly-linux-kernel-4.4.55.git / commitdiff