linux/arch/mips/kernel/pm.c
Thomas Gleixner 2874c5fd28 treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 152
Based on 1 normalized pattern(s):

  this program is free software you can redistribute it and or modify
  it under the terms of the gnu general public license as published by
  the free software foundation either version 2 of the license or at
  your option any later version

extracted by the scancode license scanner the SPDX license identifier

  GPL-2.0-or-later

has been chosen to replace the boilerplate/reference in 3029 file(s).

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Allison Randal <allison@lohutok.net>
Cc: linux-spdx@vger.kernel.org
Link: https://lkml.kernel.org/r/20190527070032.746973796@linutronix.de
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-05-30 11:26:32 -07:00

96 lines
2.0 KiB
C

// SPDX-License-Identifier: GPL-2.0-or-later
/*
* Copyright (C) 2014 Imagination Technologies Ltd.
*
* CPU PM notifiers for saving/restoring general CPU state.
*/
#include <linux/cpu_pm.h>
#include <linux/init.h>
#include <asm/dsp.h>
#include <asm/fpu.h>
#include <asm/mmu_context.h>
#include <asm/pm.h>
#include <asm/watch.h>
/* Used by PM helper macros in asm/pm.h */
struct mips_static_suspend_state mips_static_suspend_state;
/**
* mips_cpu_save() - Save general CPU state.
* Ensures that general CPU context is saved, notably FPU and DSP.
*/
static int mips_cpu_save(void)
{
/* Save FPU state */
lose_fpu(1);
/* Save DSP state */
save_dsp(current);
return 0;
}
/**
* mips_cpu_restore() - Restore general CPU state.
* Restores important CPU context.
*/
static void mips_cpu_restore(void)
{
unsigned int cpu = smp_processor_id();
/* Restore ASID */
if (current->mm)
write_c0_entryhi(cpu_asid(cpu, current->mm));
/* Restore DSP state */
restore_dsp(current);
/* Restore UserLocal */
if (cpu_has_userlocal)
write_c0_userlocal(current_thread_info()->tp_value);
/* Restore watch registers */
__restore_watch(current);
}
/**
* mips_pm_notifier() - Notifier for preserving general CPU context.
* @self: Notifier block.
* @cmd: CPU PM event.
* @v: Private data (unused).
*
* This is called when a CPU power management event occurs, and is used to
* ensure that important CPU context is preserved across a CPU power down.
*/
static int mips_pm_notifier(struct notifier_block *self, unsigned long cmd,
void *v)
{
int ret;
switch (cmd) {
case CPU_PM_ENTER:
ret = mips_cpu_save();
if (ret)
return NOTIFY_STOP;
break;
case CPU_PM_ENTER_FAILED:
case CPU_PM_EXIT:
mips_cpu_restore();
break;
}
return NOTIFY_OK;
}
static struct notifier_block mips_pm_notifier_block = {
.notifier_call = mips_pm_notifier,
};
static int __init mips_pm_init(void)
{
return cpu_pm_register_notifier(&mips_pm_notifier_block);
}
arch_initcall(mips_pm_init);