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/msr.h>
20#include <asm/smp.h>
21
22#include <linux/ftrace.h>
23#include "../../realmode/rm/wakeup.h"
24#include "sleep.h"
25
26unsigned long acpi_realmode_flags;
27
28#if defined(CONFIG_SMP) && defined(CONFIG_64BIT)
29static char temp_stack[4096];
30#endif
31
32/**
33 * acpi_get_wakeup_address - provide physical address for S3 wakeup
34 *
35 * Returns the physical address where the kernel should be resumed after the
36 * system awakes from S3, e.g. for programming into the firmware waking vector.
37 */
38unsigned long acpi_get_wakeup_address(void)
39{
40 return ((unsigned long)(real_mode_header->wakeup_start));
41}
42
43/**
44 * x86_acpi_enter_sleep_state - enter sleep state
45 * @state: Sleep state to enter.
46 *
47 * Wrapper around acpi_enter_sleep_state() to be called by assembly.
48 */
49asmlinkage acpi_status __visible x86_acpi_enter_sleep_state(u8 state)
50{
51 return acpi_enter_sleep_state(sleep_state: state);
52}
53
54/**
55 * x86_acpi_suspend_lowlevel - save kernel state
56 *
57 * Create an identity mapped page table and copy the wakeup routine to
58 * low memory.
59 */
60int x86_acpi_suspend_lowlevel(void)
61{
62 struct wakeup_header *header =
63 (struct wakeup_header *) __va(real_mode_header->wakeup_header);
64
65 if (header->signature != WAKEUP_HEADER_SIGNATURE) {
66 printk(KERN_ERR "wakeup header does not match\n");
67 return -EINVAL;
68 }
69
70 header->video_mode = saved_video_mode;
71
72 header->pmode_behavior = 0;
73
74#ifndef CONFIG_64BIT
75 native_store_gdt((struct desc_ptr *)&header->pmode_gdt);
76
77 /*
78 * We have to check that we can write back the value, and not
79 * just read it. At least on 90 nm Pentium M (Family 6, Model
80 * 13), reading an invalid MSR is not guaranteed to trap, see
81 * Erratum X4 in "Intel Pentium M Processor on 90 nm Process
82 * with 2-MB L2 Cache and Intel® Processor A100 and A110 on 90
83 * nm process with 512-KB L2 Cache Specification Update".
84 */
85 if (!rdmsr_safe(MSR_EFER,
86 &header->pmode_efer_low,
87 &header->pmode_efer_high) &&
88 !wrmsr_safe(MSR_EFER,
89 header->pmode_efer_low,
90 header->pmode_efer_high))
91 header->pmode_behavior |= (1 << WAKEUP_BEHAVIOR_RESTORE_EFER);
92#endif /* !CONFIG_64BIT */
93
94 header->pmode_cr0 = read_cr0();
95 if (__this_cpu_read(cpu_info.cpuid_level) >= 0) {
96 header->pmode_cr4 = __read_cr4();
97 header->pmode_behavior |= (1 << WAKEUP_BEHAVIOR_RESTORE_CR4);
98 }
99 if (!rdmsr_safe(MSR_IA32_MISC_ENABLE,
100 &header->pmode_misc_en_low,
101 &header->pmode_misc_en_high) &&
102 !wrmsr_safe(MSR_IA32_MISC_ENABLE,
103 low: header->pmode_misc_en_low,
104 high: header->pmode_misc_en_high))
105 header->pmode_behavior |=
106 (1 << WAKEUP_BEHAVIOR_RESTORE_MISC_ENABLE);
107 header->realmode_flags = acpi_realmode_flags;
108 header->real_magic = 0x12345678;
109
110#ifndef CONFIG_64BIT
111 header->pmode_entry = (u32)&wakeup_pmode_return;
112 header->pmode_cr3 = (u32)__pa_symbol(initial_page_table);
113 saved_magic = 0x12345678;
114#else /* CONFIG_64BIT */
115#ifdef CONFIG_SMP
116 /*
117 * As each CPU starts up, it will find its own stack pointer
118 * from its current_task->thread.sp. Typically that will be
119 * the idle thread for a newly-started AP, or even the boot
120 * CPU which will find it set to &init_task in the static
121 * per-cpu data.
122 *
123 * Make the resuming CPU use the temporary stack at startup
124 * by setting current->thread.sp to point to that. The true
125 * %rsp will be restored with the rest of the CPU context,
126 * by do_suspend_lowlevel(). And unwinders don't care about
127 * the abuse of ->thread.sp because it's a dead variable
128 * while the thread is running on the CPU anyway; the true
129 * value is in the actual %rsp register.
130 */
131 current->thread.sp = (unsigned long)temp_stack + sizeof(temp_stack);
132 /*
133 * Ensure the CPU knows which one it is when it comes back, if
134 * it isn't in parallel mode and expected to work that out for
135 * itself.
136 */
137 if (!(smpboot_control & STARTUP_PARALLEL_MASK))
138 smpboot_control = smp_processor_id();
139#endif
140 initial_code = (unsigned long)wakeup_long64;
141 saved_magic = 0x123456789abcdef0L;
142#endif /* CONFIG_64BIT */
143
144 /*
145 * Pause/unpause graph tracing around do_suspend_lowlevel as it has
146 * inconsistent call/return info after it jumps to the wakeup vector.
147 */
148 pause_graph_tracing();
149 do_suspend_lowlevel();
150 unpause_graph_tracing();
151 return 0;
152}
153
154static int __init acpi_sleep_setup(char *str)
155{
156 while ((str != NULL) && (*str != '\0')) {
157 if (strncmp(str, "s3_bios", 7) == 0)
158 acpi_realmode_flags |= 1;
159 if (strncmp(str, "s3_mode", 7) == 0)
160 acpi_realmode_flags |= 2;
161 if (strncmp(str, "s3_beep", 7) == 0)
162 acpi_realmode_flags |= 4;
163#ifdef CONFIG_HIBERNATION
164 if (strncmp(str, "s4_hwsig", 8) == 0)
165 acpi_check_s4_hw_signature = 1;
166 if (strncmp(str, "s4_nohwsig", 10) == 0)
167 acpi_check_s4_hw_signature = 0;
168#endif
169 if (strncmp(str, "nonvs", 5) == 0)
170 acpi_nvs_nosave();
171 if (strncmp(str, "nonvs_s3", 8) == 0)
172 acpi_nvs_nosave_s3();
173 if (strncmp(str, "old_ordering", 12) == 0)
174 acpi_old_suspend_ordering();
175 if (strncmp(str, "nobl", 4) == 0)
176 acpi_sleep_no_blacklist();
177 str = strchr(str, ',');
178 if (str != NULL)
179 str += strspn(str, ", \t");
180 }
181 return 1;
182}
183
184__setup("acpi_sleep=", acpi_sleep_setup);
185
186#if defined(CONFIG_HIBERNATION) && defined(CONFIG_HYPERVISOR_GUEST)
187static int __init init_s4_sigcheck(void)
188{
189 /*
190 * If running on a hypervisor, honour the ACPI specification
191 * by default and trigger a clean reboot when the hardware
192 * signature in FACS is changed after hibernation.
193 */
194 if (acpi_check_s4_hw_signature == -1 &&
195 !hypervisor_is_type(type: X86_HYPER_NATIVE))
196 acpi_check_s4_hw_signature = 1;
197
198 return 0;
199}
200/* This must happen before acpi_init() which is a subsys initcall */
201arch_initcall(init_s4_sigcheck);
202#endif
203