xref: /openbmc/linux/arch/x86/kernel/acpi/sleep.c (revision 9a32dd32)
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  */
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  */
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  */
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 	/*
115 	 * As each CPU starts up, it will find its own stack pointer
116 	 * from its current_task->thread.sp. Typically that will be
117 	 * the idle thread for a newly-started AP, or even the boot
118 	 * CPU which will find it set to &init_task in the static
119 	 * per-cpu data.
120 	 *
121 	 * Make the resuming CPU use the temporary stack at startup
122 	 * by setting current->thread.sp to point to that. The true
123 	 * %rsp will be restored with the rest of the CPU context,
124 	 * by do_suspend_lowlevel(). And unwinders don't care about
125 	 * the abuse of ->thread.sp because it's a dead variable
126 	 * while the thread is running on the CPU anyway; the true
127 	 * value is in the actual %rsp register.
128 	 */
129 	current->thread.sp = (unsigned long)temp_stack + sizeof(temp_stack);
130 	smpboot_control = smp_processor_id();
131 #endif
132 	initial_code = (unsigned long)wakeup_long64;
133 	saved_magic = 0x123456789abcdef0L;
134 #endif /* CONFIG_64BIT */
135 
136 	/*
137 	 * Pause/unpause graph tracing around do_suspend_lowlevel as it has
138 	 * inconsistent call/return info after it jumps to the wakeup vector.
139 	 */
140 	pause_graph_tracing();
141 	do_suspend_lowlevel();
142 	unpause_graph_tracing();
143 	return 0;
144 }
145 
146 static int __init acpi_sleep_setup(char *str)
147 {
148 	while ((str != NULL) && (*str != '\0')) {
149 		if (strncmp(str, "s3_bios", 7) == 0)
150 			acpi_realmode_flags |= 1;
151 		if (strncmp(str, "s3_mode", 7) == 0)
152 			acpi_realmode_flags |= 2;
153 		if (strncmp(str, "s3_beep", 7) == 0)
154 			acpi_realmode_flags |= 4;
155 #ifdef CONFIG_HIBERNATION
156 		if (strncmp(str, "s4_hwsig", 8) == 0)
157 			acpi_check_s4_hw_signature = 1;
158 		if (strncmp(str, "s4_nohwsig", 10) == 0)
159 			acpi_check_s4_hw_signature = 0;
160 #endif
161 		if (strncmp(str, "nonvs", 5) == 0)
162 			acpi_nvs_nosave();
163 		if (strncmp(str, "nonvs_s3", 8) == 0)
164 			acpi_nvs_nosave_s3();
165 		if (strncmp(str, "old_ordering", 12) == 0)
166 			acpi_old_suspend_ordering();
167 		if (strncmp(str, "nobl", 4) == 0)
168 			acpi_sleep_no_blacklist();
169 		str = strchr(str, ',');
170 		if (str != NULL)
171 			str += strspn(str, ", \t");
172 	}
173 	return 1;
174 }
175 
176 __setup("acpi_sleep=", acpi_sleep_setup);
177 
178 #if defined(CONFIG_HIBERNATION) && defined(CONFIG_HYPERVISOR_GUEST)
179 static int __init init_s4_sigcheck(void)
180 {
181 	/*
182 	 * If running on a hypervisor, honour the ACPI specification
183 	 * by default and trigger a clean reboot when the hardware
184 	 * signature in FACS is changed after hibernation.
185 	 */
186 	if (acpi_check_s4_hw_signature == -1 &&
187 	    !hypervisor_is_type(X86_HYPER_NATIVE))
188 		acpi_check_s4_hw_signature = 1;
189 
190 	return 0;
191 }
192 /* This must happen before acpi_init() which is a subsys initcall */
193 arch_initcall(init_s4_sigcheck);
194 #endif
195