[PATCH] swsusp: add read-speed instrumentation
[linux-2.6] / kernel / power / smp.c
1 /*
2  * drivers/power/smp.c - Functions for stopping other CPUs.
3  *
4  * Copyright 2004 Pavel Machek <pavel@suse.cz>
5  * Copyright (C) 2002-2003 Nigel Cunningham <ncunningham@clear.net.nz>
6  *
7  * This file is released under the GPLv2.
8  */
9
10 #undef DEBUG
11
12 #include <linux/smp_lock.h>
13 #include <linux/interrupt.h>
14 #include <linux/suspend.h>
15 #include <linux/module.h>
16 #include <linux/cpu.h>
17 #include <asm/atomic.h>
18 #include <asm/tlbflush.h>
19
20 /* This is protected by pm_sem semaphore */
21 static cpumask_t frozen_cpus;
22
23 void disable_nonboot_cpus(void)
24 {
25         int cpu, error;
26
27         error = 0;
28         cpus_clear(frozen_cpus);
29         printk("Freezing cpus ...\n");
30         for_each_online_cpu(cpu) {
31                 if (cpu == 0)
32                         continue;
33                 error = cpu_down(cpu);
34                 if (!error) {
35                         cpu_set(cpu, frozen_cpus);
36                         printk("CPU%d is down\n", cpu);
37                         continue;
38                 }
39                 printk("Error taking cpu %d down: %d\n", cpu, error);
40         }
41         BUG_ON(raw_smp_processor_id() != 0);
42         if (error)
43                 panic("cpus not sleeping");
44 }
45
46 void enable_nonboot_cpus(void)
47 {
48         int cpu, error;
49
50         printk("Thawing cpus ...\n");
51         for_each_cpu_mask(cpu, frozen_cpus) {
52                 error = cpu_up(cpu);
53                 if (!error) {
54                         printk("CPU%d is up\n", cpu);
55                         continue;
56                 }
57                 printk("Error taking cpu %d up: %d\n", cpu, error);
58                 panic("Not enough cpus");
59         }
60         cpus_clear(frozen_cpus);
61 }
62