blob: 486ed2bf25148804cb760509e081af59fbb5c861 (
plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
|
// 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);
|
