linux/kernel/power/smp.c

65 lines
1.3 KiB
C

/*
* drivers/power/smp.c - Functions for stopping other CPUs.
*
* Copyright 2004 Pavel Machek <pavel@suse.cz>
* Copyright (C) 2002-2003 Nigel Cunningham <ncunningham@clear.net.nz>
*
* This file is released under the GPLv2.
*/
#undef DEBUG
#include <linux/smp_lock.h>
#include <linux/interrupt.h>
#include <linux/suspend.h>
#include <linux/module.h>
#include <linux/cpu.h>
#include <asm/atomic.h>
#include <asm/tlbflush.h>
/* This is protected by pm_sem semaphore */
static cpumask_t frozen_cpus;
void disable_nonboot_cpus(void)
{
int cpu, error;
error = 0;
cpus_clear(frozen_cpus);
printk("Freezing cpus ...\n");
for_each_online_cpu(cpu) {
if (cpu == 0)
continue;
error = cpu_down(cpu);
if (!error) {
cpu_set(cpu, frozen_cpus);
printk("CPU%d is down\n", cpu);
continue;
}
printk("Error taking cpu %d down: %d\n", cpu, error);
}
BUG_ON(raw_smp_processor_id() != 0);
if (error)
panic("cpus not sleeping");
}
void enable_nonboot_cpus(void)
{
int cpu, error;
printk("Thawing cpus ...\n");
for_each_cpu_mask(cpu, frozen_cpus) {
error = smp_prepare_cpu(cpu);
if (!error)
error = cpu_up(cpu);
if (!error) {
printk("CPU%d is up\n", cpu);
continue;
}
printk("Error taking cpu %d up: %d\n", cpu, error);
panic("Not enough cpus");
}
cpus_clear(frozen_cpus);
}