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