mirror of
https://mirrors.bfsu.edu.cn/git/linux.git
synced 2024-11-18 17:54:13 +08:00
a7e89326b4
Commitf51246efee("MIPS: Get rid of finish_arch_switch().") moved the __restore_watch() call from finish_arch_switch() (i.e. after resume() returns) to before the resume() call in switch_to(). This results in watchpoints only being restored when a task is descheduled, preventing the watchpoints from being effective most of the time, except due to chance before the watchpoints are lazily removed. Fix the call sequence from switch_to() through to mips_install_watch_registers() to pass the task_struct pointer of the next task, instead of using current. This allows the watchpoints for the next (non-current) task to be restored without reintroducing finish_arch_switch(). Fixes:f51246efee("MIPS: Get rid of finish_arch_switch().") Signed-off-by: James Hogan <james.hogan@imgtec.com> Cc: Paul Burton <paul.burton@imgtec.com> Cc: linux-mips@linux-mips.org Cc: <stable@vger.kernel.org> # 4.3.x- Patchwork: https://patchwork.linux-mips.org/patch/12726/ Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
100 lines
2.2 KiB
C
100 lines
2.2 KiB
C
/*
|
|
* Copyright (C) 2014 Imagination Technologies Ltd.
|
|
*
|
|
* 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.
|
|
*
|
|
* 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);
|