1#include <linux/kernel.h>
 2#include <linux/module.h>
 3#include <linux/init.h>
 4#include <linux/blkdev.h>
 5#include <linux/list.h>
 6#include <linux/llist.h>
 7#include <linux/smp.h>
 8#include <linux/cpu.h>
 9
10#include <linux/blk-mq.h>
11#include "blk-mq.h"
12
13static LIST_HEAD(blk_mq_cpu_notify_list);
14static DEFINE_RAW_SPINLOCK(blk_mq_cpu_notify_lock);
15
16static int blk_mq_main_cpu_notify(struct notifier_block *self,
17				  unsigned long action, void *hcpu)
18{
19	unsigned int cpu = (unsigned long) hcpu;
20	struct blk_mq_cpu_notifier *notify;
21
22	raw_spin_lock(&blk_mq_cpu_notify_lock);
23
24	list_for_each_entry(notify, &blk_mq_cpu_notify_list, list)
25		notify->notify(notify->data, action, cpu);
26
27	raw_spin_unlock(&blk_mq_cpu_notify_lock);
28	return NOTIFY_OK;
29}
30
31void blk_mq_register_cpu_notifier(struct blk_mq_cpu_notifier *notifier)
32{
33	BUG_ON(!notifier->notify);
34
35	raw_spin_lock(&blk_mq_cpu_notify_lock);
36	list_add_tail(&notifier->list, &blk_mq_cpu_notify_list);
37	raw_spin_unlock(&blk_mq_cpu_notify_lock);
38}
39
40void blk_mq_unregister_cpu_notifier(struct blk_mq_cpu_notifier *notifier)
41{
42	raw_spin_lock(&blk_mq_cpu_notify_lock);
43	list_del(&notifier->list);
44	raw_spin_unlock(&blk_mq_cpu_notify_lock);
45}
46
47void blk_mq_init_cpu_notifier(struct blk_mq_cpu_notifier *notifier,
48			      void (*fn)(void *, unsigned long, unsigned int),
49			      void *data)
50{
51	notifier->notify = fn;
52	notifier->data = data;
53}
54
55void __init blk_mq_cpu_init(void)
56{
57	hotcpu_notifier(blk_mq_main_cpu_notify, 0);
58}