block/blk-mq-cpu.c

   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
  13 static LIST_HEAD(blk_mq_cpu_notify_list);
  14 static DEFINE_RAW_SPINLOCK(blk_mq_cpu_notify_lock);
  15
  16 static 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
  31 void 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
  40 void 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
  47 void 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
  55 void __init blk_mq_cpu_init(void)
  56 {
  57         hotcpu_notifier(blk_mq_main_cpu_notify, 0);
  58 }