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/*
* 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.
*
* Copyright (C) 2001, 06 by Ralf Baechle (ralf@linux-mips.org)
* Copyright (C) 2001 MIPS Technologies, Inc.
*/
#include <linux/kernel.h>
#include <linux/export.h>
#include <linux/pm.h>
#include <linux/types.h>
#include <linux/reboot.h>
#include <linux/delay.h>
#include <asm/compiler.h>
#include <asm/idle.h>
#include <asm/mipsregs.h>
#include <asm/reboot.h>
/*
* Urgs ... Too many MIPS machines to handle this in a generic way.
* So handle all using function pointers to machine specific
* functions.
*/
void (*_machine_restart)(char *command);
void (*_machine_halt)(void);
void (*pm_power_off)(void);
EXPORT_SYMBOL(pm_power_off);
static void machine_hang(void)
{
/*
* We're hanging the system so we don't want to be interrupted anymore.
* Any interrupt handlers that ran would at best be useless & at worst
* go awry because the system isn't in a functional state.
*/
local_irq_disable();
/*
* Mask all interrupts, giving us a better chance of remaining in the
* low power wait state.
*/
clear_c0_status(ST0_IM);
while (true) {
if (cpu_has_mips_r) {
/*
* We know that the wait instruction is supported so
* make use of it directly, leaving interrupts
* disabled.
*/
asm volatile(
".set push\n\t"
".set " MIPS_ISA_ARCH_LEVEL "\n\t"
"wait\n\t"
".set pop");
} else if (cpu_wait) {
/*
* Try the cpu_wait() callback. This isn't ideal since
* it'll re-enable interrupts, but that ought to be
* harmless given that they're all masked.
*/
cpu_wait();
local_irq_disable();
} else {
/*
* We're going to burn some power running round the
* loop, but we don't really have a choice. This isn't
* a path we should expect to run for long during
* typical use anyway.
*/
}
/*
* In most modern MIPS CPUs interrupts will cause the wait
* instruction to graduate even when disabled, and in some
* cases even when masked. In order to prevent a timer
* interrupt from continuously taking us out of the low power
* wait state, we clear any pending timer interrupt here.
*/
if (cpu_has_counter)
write_c0_compare(0);
}
}
void machine_restart(char *command)
{
if (_machine_restart)
_machine_restart(command);
#ifdef CONFIG_SMP
preempt_disable();
smp_send_stop();
#endif
do_kernel_restart(command);
mdelay(1000);
pr_emerg("Reboot failed -- System halted\n");
machine_hang();
}
void machine_halt(void)
{
if (_machine_halt)
_machine_halt();
#ifdef CONFIG_SMP
preempt_disable();
smp_send_stop();
#endif
machine_hang();
}
void machine_power_off(void)
{
do_kernel_power_off();
#ifdef CONFIG_SMP
preempt_disable();
smp_send_stop();
#endif
machine_hang();
}
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