summaryrefslogtreecommitdiff
path: root/arch/x86/kernel/acpi/sleep.c
blob: cc1fea76aab05dfabb69ca59e3bff20f0643914d (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
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
// SPDX-License-Identifier: GPL-2.0
/*
 * sleep.c - x86-specific ACPI sleep support.
 *
 *  Copyright (C) 2001-2003 Patrick Mochel
 *  Copyright (C) 2001-2003 Pavel Machek <pavel@ucw.cz>
 */

#include <linux/acpi.h>
#include <linux/memblock.h>
#include <linux/dmi.h>
#include <linux/cpumask.h>
#include <linux/pgtable.h>
#include <asm/segment.h>
#include <asm/desc.h>
#include <asm/cacheflush.h>
#include <asm/realmode.h>

#include <linux/ftrace.h>
#include "../../realmode/rm/wakeup.h"
#include "sleep.h"

unsigned long acpi_realmode_flags;

#if defined(CONFIG_SMP) && defined(CONFIG_64BIT)
static char temp_stack[4096];
#endif

/**
 * acpi_get_wakeup_address - provide physical address for S3 wakeup
 *
 * Returns the physical address where the kernel should be resumed after the
 * system awakes from S3, e.g. for programming into the firmware waking vector.
 */
unsigned long acpi_get_wakeup_address(void)
{
	return ((unsigned long)(real_mode_header->wakeup_start));
}

/**
 * x86_acpi_enter_sleep_state - enter sleep state
 * @state: Sleep state to enter.
 *
 * Wrapper around acpi_enter_sleep_state() to be called by assmebly.
 */
asmlinkage acpi_status __visible x86_acpi_enter_sleep_state(u8 state)
{
	return acpi_enter_sleep_state(state);
}

/**
 * x86_acpi_suspend_lowlevel - save kernel state
 *
 * Create an identity mapped page table and copy the wakeup routine to
 * low memory.
 */
int x86_acpi_suspend_lowlevel(void)
{
	struct wakeup_header *header =
		(struct wakeup_header *) __va(real_mode_header->wakeup_header);

	if (header->signature != WAKEUP_HEADER_SIGNATURE) {
		printk(KERN_ERR "wakeup header does not match\n");
		return -EINVAL;
	}

	header->video_mode = saved_video_mode;

	header->pmode_behavior = 0;

#ifndef CONFIG_64BIT
	native_store_gdt((struct desc_ptr *)&header->pmode_gdt);

	/*
	 * We have to check that we can write back the value, and not
	 * just read it.  At least on 90 nm Pentium M (Family 6, Model
	 * 13), reading an invalid MSR is not guaranteed to trap, see
	 * Erratum X4 in "Intel Pentium M Processor on 90 nm Process
	 * with 2-MB L2 Cache and Intel® Processor A100 and A110 on 90
	 * nm process with 512-KB L2 Cache Specification Update".
	 */
	if (!rdmsr_safe(MSR_EFER,
			&header->pmode_efer_low,
			&header->pmode_efer_high) &&
	    !wrmsr_safe(MSR_EFER,
			header->pmode_efer_low,
			header->pmode_efer_high))
		header->pmode_behavior |= (1 << WAKEUP_BEHAVIOR_RESTORE_EFER);
#endif /* !CONFIG_64BIT */

	header->pmode_cr0 = read_cr0();
	if (__this_cpu_read(cpu_info.cpuid_level) >= 0) {
		header->pmode_cr4 = __read_cr4();
		header->pmode_behavior |= (1 << WAKEUP_BEHAVIOR_RESTORE_CR4);
	}
	if (!rdmsr_safe(MSR_IA32_MISC_ENABLE,
			&header->pmode_misc_en_low,
			&header->pmode_misc_en_high) &&
	    !wrmsr_safe(MSR_IA32_MISC_ENABLE,
			header->pmode_misc_en_low,
			header->pmode_misc_en_high))
		header->pmode_behavior |=
			(1 << WAKEUP_BEHAVIOR_RESTORE_MISC_ENABLE);
	header->realmode_flags = acpi_realmode_flags;
	header->real_magic = 0x12345678;

#ifndef CONFIG_64BIT
	header->pmode_entry = (u32)&wakeup_pmode_return;
	header->pmode_cr3 = (u32)__pa_symbol(initial_page_table);
	saved_magic = 0x12345678;
#else /* CONFIG_64BIT */
#ifdef CONFIG_SMP
	initial_stack = (unsigned long)temp_stack + sizeof(temp_stack);
	early_gdt_descr.address =
			(unsigned long)get_cpu_gdt_rw(smp_processor_id());
	initial_gs = per_cpu_offset(smp_processor_id());
#endif
	initial_code = (unsigned long)wakeup_long64;
       saved_magic = 0x123456789abcdef0L;
#endif /* CONFIG_64BIT */

	/*
	 * Pause/unpause graph tracing around do_suspend_lowlevel as it has
	 * inconsistent call/return info after it jumps to the wakeup vector.
	 */
	pause_graph_tracing();
	do_suspend_lowlevel();
	unpause_graph_tracing();
	return 0;
}

static int __init acpi_sleep_setup(char *str)
{
	while ((str != NULL) && (*str != '\0')) {
		if (strncmp(str, "s3_bios", 7) == 0)
			acpi_realmode_flags |= 1;
		if (strncmp(str, "s3_mode", 7) == 0)
			acpi_realmode_flags |= 2;
		if (strncmp(str, "s3_beep", 7) == 0)
			acpi_realmode_flags |= 4;
#ifdef CONFIG_HIBERNATION
		if (strncmp(str, "s4_nohwsig", 10) == 0)
			acpi_no_s4_hw_signature();
#endif
		if (strncmp(str, "nonvs", 5) == 0)
			acpi_nvs_nosave();
		if (strncmp(str, "nonvs_s3", 8) == 0)
			acpi_nvs_nosave_s3();
		if (strncmp(str, "old_ordering", 12) == 0)
			acpi_old_suspend_ordering();
		if (strncmp(str, "nobl", 4) == 0)
			acpi_sleep_no_blacklist();
		str = strchr(str, ',');
		if (str != NULL)
			str += strspn(str, ", \t");
	}
	return 1;
}

__setup("acpi_sleep=", acpi_sleep_setup);