1// SPDX-License-Identifier: GPL-2.0
2/*
3 * sleep.c - x86-specific ACPI sleep support.
4 *
5 * Copyright (C) 2001-2003 Patrick Mochel
6 * Copyright (C) 2001-2003 Pavel Machek <pavel@ucw.cz>
7 */
8
9#include <linux/acpi.h>
10#include <linux/memblock.h>
11#include <linux/dmi.h>
12#include <linux/cpumask.h>
13#include <linux/pgtable.h>
14#include <asm/segment.h>
15#include <asm/desc.h>
16#include <asm/cacheflush.h>
17#include <asm/realmode.h>
18#include <asm/hypervisor.h>
19#include <asm/smp.h>
20
21#include <linux/ftrace.h>
22#include "../../realmode/rm/wakeup.h"
23#include "sleep.h"
24
25unsigned long acpi_realmode_flags;
26
27#if defined(CONFIG_SMP) && defined(CONFIG_64BIT)
28static char temp_stack[4096];
29#endif
30
31/**
32 * acpi_get_wakeup_address - provide physical address for S3 wakeup
33 *
34 * Returns the physical address where the kernel should be resumed after the
35 * system awakes from S3, e.g. for programming into the firmware waking vector.
36 */
37unsigned long acpi_get_wakeup_address(void)
38{
39 return ((unsigned long)(real_mode_header->wakeup_start));
40}
41
42/**
43 * x86_acpi_enter_sleep_state - enter sleep state
44 * @state: Sleep state to enter.
45 *
46 * Wrapper around acpi_enter_sleep_state() to be called by assembly.
47 */
48asmlinkage acpi_status __visible x86_acpi_enter_sleep_state(u8 state)
49{
50 return acpi_enter_sleep_state(sleep_state: state);
51}
52
53/**
54 * x86_acpi_suspend_lowlevel - save kernel state
55 *
56 * Create an identity mapped page table and copy the wakeup routine to
57 * low memory.
58 */
59int x86_acpi_suspend_lowlevel(void)
60{
61 struct wakeup_header *header =
62 (struct wakeup_header *) __va(real_mode_header->wakeup_header);
63
64 if (header->signature != WAKEUP_HEADER_SIGNATURE) {
65 printk(KERN_ERR "wakeup header does not match\n");
66 return -EINVAL;
67 }
68
69 header->video_mode = saved_video_mode;
70
71 header->pmode_behavior = 0;
72
73#ifndef CONFIG_64BIT
74 native_store_gdt((struct desc_ptr *)&header->pmode_gdt);
75
76 /*
77 * We have to check that we can write back the value, and not
78 * just read it. At least on 90 nm Pentium M (Family 6, Model
79 * 13), reading an invalid MSR is not guaranteed to trap, see
80 * Erratum X4 in "Intel Pentium M Processor on 90 nm Process
81 * with 2-MB L2 Cache and Intel® Processor A100 and A110 on 90
82 * nm process with 512-KB L2 Cache Specification Update".
83 */
84 if (!rdmsr_safe(MSR_EFER,
85 &header->pmode_efer_low,
86 &header->pmode_efer_high) &&
87 !wrmsr_safe(MSR_EFER,
88 header->pmode_efer_low,
89 header->pmode_efer_high))
90 header->pmode_behavior |= (1 << WAKEUP_BEHAVIOR_RESTORE_EFER);
91#endif /* !CONFIG_64BIT */
92
93 header->pmode_cr0 = read_cr0();
94 if (__this_cpu_read(cpu_info.cpuid_level) >= 0) {
95 header->pmode_cr4 = __read_cr4();
96 header->pmode_behavior |= (1 << WAKEUP_BEHAVIOR_RESTORE_CR4);
97 }
98 if (!rdmsr_safe(MSR_IA32_MISC_ENABLE,
99 &header->pmode_misc_en_low,
100 &header->pmode_misc_en_high) &&
101 !wrmsr_safe(MSR_IA32_MISC_ENABLE,
102 header->pmode_misc_en_low,
103 header->pmode_misc_en_high))
104 header->pmode_behavior |=
105 (1 << WAKEUP_BEHAVIOR_RESTORE_MISC_ENABLE);
106 header->realmode_flags = acpi_realmode_flags;
107 header->real_magic = 0x12345678;
108
109#ifndef CONFIG_64BIT
110 header->pmode_entry = (u32)&wakeup_pmode_return;
111 header->pmode_cr3 = (u32)__pa_symbol(initial_page_table);
112 saved_magic = 0x12345678;
113#else /* CONFIG_64BIT */
114#ifdef CONFIG_SMP
115 /*
116 * As each CPU starts up, it will find its own stack pointer
117 * from its current_task->thread.sp. Typically that will be
118 * the idle thread for a newly-started AP, or even the boot
119 * CPU which will find it set to &init_task in the static
120 * per-cpu data.
121 *
122 * Make the resuming CPU use the temporary stack at startup
123 * by setting current->thread.sp to point to that. The true
124 * %rsp will be restored with the rest of the CPU context,
125 * by do_suspend_lowlevel(). And unwinders don't care about
126 * the abuse of ->thread.sp because it's a dead variable
127 * while the thread is running on the CPU anyway; the true
128 * value is in the actual %rsp register.
129 */
130 current->thread.sp = (unsigned long)temp_stack + sizeof(temp_stack);
131 /*
132 * Ensure the CPU knows which one it is when it comes back, if
133 * it isn't in parallel mode and expected to work that out for
134 * itself.
135 */
136 if (!(smpboot_control & STARTUP_PARALLEL_MASK))
137 smpboot_control = smp_processor_id();
138#endif
139 initial_code = (unsigned long)wakeup_long64;
140 saved_magic = 0x123456789abcdef0L;
141#endif /* CONFIG_64BIT */
142
143 /*
144 * Pause/unpause graph tracing around do_suspend_lowlevel as it has
145 * inconsistent call/return info after it jumps to the wakeup vector.
146 */
147 pause_graph_tracing();
148 do_suspend_lowlevel();
149 unpause_graph_tracing();
150 return 0;
151}
152
153static int __init acpi_sleep_setup(char *str)
154{
155 while ((str != NULL) && (*str != '\0')) {
156 if (strncmp(str, "s3_bios", 7) == 0)
157 acpi_realmode_flags |= 1;
158 if (strncmp(str, "s3_mode", 7) == 0)
159 acpi_realmode_flags |= 2;
160 if (strncmp(str, "s3_beep", 7) == 0)
161 acpi_realmode_flags |= 4;
162#ifdef CONFIG_HIBERNATION
163 if (strncmp(str, "s4_hwsig", 8) == 0)
164 acpi_check_s4_hw_signature = 1;
165 if (strncmp(str, "s4_nohwsig", 10) == 0)
166 acpi_check_s4_hw_signature = 0;
167#endif
168 if (strncmp(str, "nonvs", 5) == 0)
169 acpi_nvs_nosave();
170 if (strncmp(str, "nonvs_s3", 8) == 0)
171 acpi_nvs_nosave_s3();
172 if (strncmp(str, "old_ordering", 12) == 0)
173 acpi_old_suspend_ordering();
174 if (strncmp(str, "nobl", 4) == 0)
175 acpi_sleep_no_blacklist();
176 str = strchr(str, ',');
177 if (str != NULL)
178 str += strspn(str, ", \t");
179 }
180 return 1;
181}
182
183__setup("acpi_sleep=", acpi_sleep_setup);
184
185#if defined(CONFIG_HIBERNATION) && defined(CONFIG_HYPERVISOR_GUEST)
186static int __init init_s4_sigcheck(void)
187{
188 /*
189 * If running on a hypervisor, honour the ACPI specification
190 * by default and trigger a clean reboot when the hardware
191 * signature in FACS is changed after hibernation.
192 */
193 if (acpi_check_s4_hw_signature == -1 &&
194 !hypervisor_is_type(type: X86_HYPER_NATIVE))
195 acpi_check_s4_hw_signature = 1;
196
197 return 0;
198}
199/* This must happen before acpi_init() which is a subsys initcall */
200arch_initcall(init_s4_sigcheck);
201#endif
202

source code of linux/arch/x86/kernel/acpi/sleep.c