Linux-2.6.12-rc2
Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
This commit is contained in:
85
kernel/power/smp.c
Normal file
85
kernel/power/smp.c
Normal file
@@ -0,0 +1,85 @@
|
||||
/*
|
||||
* 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 <asm/atomic.h>
|
||||
#include <asm/tlbflush.h>
|
||||
|
||||
static atomic_t cpu_counter, freeze;
|
||||
|
||||
|
||||
static void smp_pause(void * data)
|
||||
{
|
||||
struct saved_context ctxt;
|
||||
__save_processor_state(&ctxt);
|
||||
printk("Sleeping in:\n");
|
||||
dump_stack();
|
||||
atomic_inc(&cpu_counter);
|
||||
while (atomic_read(&freeze)) {
|
||||
/* FIXME: restore takes place at random piece inside this.
|
||||
This should probably be written in assembly, and
|
||||
preserve general-purpose registers, too
|
||||
|
||||
What about stack? We may need to move to new stack here.
|
||||
|
||||
This should better be ran with interrupts disabled.
|
||||
*/
|
||||
cpu_relax();
|
||||
barrier();
|
||||
}
|
||||
atomic_dec(&cpu_counter);
|
||||
__restore_processor_state(&ctxt);
|
||||
}
|
||||
|
||||
static cpumask_t oldmask;
|
||||
|
||||
void disable_nonboot_cpus(void)
|
||||
{
|
||||
printk("Freezing CPUs (at %d)", smp_processor_id());
|
||||
oldmask = current->cpus_allowed;
|
||||
set_cpus_allowed(current, cpumask_of_cpu(0));
|
||||
current->state = TASK_INTERRUPTIBLE;
|
||||
schedule_timeout(HZ);
|
||||
printk("...");
|
||||
BUG_ON(smp_processor_id() != 0);
|
||||
|
||||
/* FIXME: for this to work, all the CPUs must be running
|
||||
* "idle" thread (or we deadlock). Is that guaranteed? */
|
||||
|
||||
atomic_set(&cpu_counter, 0);
|
||||
atomic_set(&freeze, 1);
|
||||
smp_call_function(smp_pause, NULL, 0, 0);
|
||||
while (atomic_read(&cpu_counter) < (num_online_cpus() - 1)) {
|
||||
cpu_relax();
|
||||
barrier();
|
||||
}
|
||||
printk("ok\n");
|
||||
}
|
||||
|
||||
void enable_nonboot_cpus(void)
|
||||
{
|
||||
printk("Restarting CPUs");
|
||||
atomic_set(&freeze, 0);
|
||||
while (atomic_read(&cpu_counter)) {
|
||||
cpu_relax();
|
||||
barrier();
|
||||
}
|
||||
printk("...");
|
||||
set_cpus_allowed(current, oldmask);
|
||||
schedule();
|
||||
printk("ok\n");
|
||||
|
||||
}
|
||||
|
||||
|
Reference in New Issue
Block a user