linux/arch/sh/kernel/idle.c
Paul Mundt 2e046b9487 sh: Provide cpu_idle_wait() to fix up cpuidle/SMP build.
Crib the x86 cpu_idle_wait() implementation and shove it in with the
idle code, subsequently enabling ARCH_HAS_CPU_IDLE_WAIT.

Signed-off-by: Paul Mundt <lethal@linux-sh.org>
2009-06-23 17:30:17 +09:00

103 lines
2.1 KiB
C

/*
* The idle loop for all SuperH platforms.
*
* Copyright (C) 2002 - 2009 Paul Mundt
*
* This file is subject to the terms and conditions of the GNU General Public
* License. See the file "COPYING" in the main directory of this archive
* for more details.
*/
#include <linux/module.h>
#include <linux/init.h>
#include <linux/mm.h>
#include <linux/pm.h>
#include <linux/tick.h>
#include <linux/preempt.h>
#include <linux/thread_info.h>
#include <linux/irqflags.h>
#include <linux/smp.h>
#include <asm/pgalloc.h>
#include <asm/system.h>
#include <asm/atomic.h>
static int hlt_counter;
void (*pm_idle)(void);
void (*pm_power_off)(void);
EXPORT_SYMBOL(pm_power_off);
static int __init nohlt_setup(char *__unused)
{
hlt_counter = 1;
return 1;
}
__setup("nohlt", nohlt_setup);
static int __init hlt_setup(char *__unused)
{
hlt_counter = 0;
return 1;
}
__setup("hlt", hlt_setup);
void default_idle(void)
{
if (!hlt_counter) {
clear_thread_flag(TIF_POLLING_NRFLAG);
smp_mb__after_clear_bit();
set_bl_bit();
stop_critical_timings();
while (!need_resched())
cpu_sleep();
start_critical_timings();
clear_bl_bit();
set_thread_flag(TIF_POLLING_NRFLAG);
} else
while (!need_resched())
cpu_relax();
}
void cpu_idle(void)
{
set_thread_flag(TIF_POLLING_NRFLAG);
/* endless idle loop with no priority at all */
while (1) {
void (*idle)(void) = pm_idle;
if (!idle)
idle = default_idle;
tick_nohz_stop_sched_tick(1);
while (!need_resched())
idle();
tick_nohz_restart_sched_tick();
preempt_enable_no_resched();
schedule();
preempt_disable();
check_pgt_cache();
}
}
static void do_nothing(void *unused)
{
}
/*
* cpu_idle_wait - Used to ensure that all the CPUs discard old value of
* pm_idle and update to new pm_idle value. Required while changing pm_idle
* handler on SMP systems.
*
* Caller must have changed pm_idle to the new value before the call. Old
* pm_idle value will not be used by any CPU after the return of this function.
*/
void cpu_idle_wait(void)
{
smp_mb();
/* kick all the CPUs so that they exit out of pm_idle */
smp_call_function(do_nothing, NULL, 1);
}
EXPORT_SYMBOL_GPL(cpu_idle_wait);