43117a0828
Fix some smp_processor_id-in-preemptible warnings Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
86 lines
1.9 KiB
C
86 lines
1.9 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 <asm/atomic.h>
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#include <asm/tlbflush.h>
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static atomic_t cpu_counter, freeze;
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static void smp_pause(void * data)
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{
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struct saved_context ctxt;
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__save_processor_state(&ctxt);
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printk("Sleeping in:\n");
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dump_stack();
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atomic_inc(&cpu_counter);
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while (atomic_read(&freeze)) {
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/* FIXME: restore takes place at random piece inside this.
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This should probably be written in assembly, and
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preserve general-purpose registers, too
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What about stack? We may need to move to new stack here.
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This should better be ran with interrupts disabled.
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*/
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cpu_relax();
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barrier();
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}
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atomic_dec(&cpu_counter);
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__restore_processor_state(&ctxt);
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}
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static cpumask_t oldmask;
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void disable_nonboot_cpus(void)
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{
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oldmask = current->cpus_allowed;
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set_cpus_allowed(current, cpumask_of_cpu(0));
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printk("Freezing CPUs (at %d)", _smp_processor_id());
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current->state = TASK_INTERRUPTIBLE;
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schedule_timeout(HZ);
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printk("...");
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BUG_ON(_smp_processor_id() != 0);
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/* FIXME: for this to work, all the CPUs must be running
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* "idle" thread (or we deadlock). Is that guaranteed? */
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atomic_set(&cpu_counter, 0);
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atomic_set(&freeze, 1);
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smp_call_function(smp_pause, NULL, 0, 0);
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while (atomic_read(&cpu_counter) < (num_online_cpus() - 1)) {
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cpu_relax();
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barrier();
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}
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printk("ok\n");
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}
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void enable_nonboot_cpus(void)
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{
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printk("Restarting CPUs");
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atomic_set(&freeze, 0);
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while (atomic_read(&cpu_counter)) {
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cpu_relax();
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barrier();
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}
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printk("...");
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set_cpus_allowed(current, oldmask);
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schedule();
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printk("ok\n");
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}
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