5a72e04df5
Using CPU hotplug to support suspend/resume SMP. Both S3 and S4 use disable/enable_nonboot_cpus API. The S4 part is based on Pavel's original S4 SMP patch. Signed-off-by: Li Shaohua<shaohua.li@intel.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
65 lines
1.3 KiB
C
65 lines
1.3 KiB
C
/*
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* drivers/power/smp.c - Functions for stopping other CPUs.
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*
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* Copyright 2004 Pavel Machek <pavel@suse.cz>
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* Copyright (C) 2002-2003 Nigel Cunningham <ncunningham@clear.net.nz>
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*
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* This file is released under the GPLv2.
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*/
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#undef DEBUG
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#include <linux/smp_lock.h>
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#include <linux/interrupt.h>
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#include <linux/suspend.h>
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#include <linux/module.h>
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#include <linux/cpu.h>
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#include <asm/atomic.h>
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#include <asm/tlbflush.h>
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/* This is protected by pm_sem semaphore */
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static cpumask_t frozen_cpus;
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void disable_nonboot_cpus(void)
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{
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int cpu, error;
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error = 0;
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cpus_clear(frozen_cpus);
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printk("Freezing cpus ...\n");
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for_each_online_cpu(cpu) {
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if (cpu == 0)
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continue;
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error = cpu_down(cpu);
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if (!error) {
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cpu_set(cpu, frozen_cpus);
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printk("CPU%d is down\n", cpu);
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continue;
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}
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printk("Error taking cpu %d down: %d\n", cpu, error);
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}
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BUG_ON(smp_processor_id() != 0);
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if (error)
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panic("cpus not sleeping");
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}
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void enable_nonboot_cpus(void)
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{
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int cpu, error;
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printk("Thawing cpus ...\n");
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for_each_cpu_mask(cpu, frozen_cpus) {
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error = smp_prepare_cpu(cpu);
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if (!error)
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error = cpu_up(cpu);
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if (!error) {
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printk("CPU%d is up\n", cpu);
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continue;
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}
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printk("Error taking cpu %d up: %d\n", cpu, error);
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panic("Not enough cpus");
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}
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cpus_clear(frozen_cpus);
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}
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