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1 /*
2  * sleep.c - x86-specific ACPI sleep support.
3  *
4  *  Copyright (C) 2001-2003 Patrick Mochel
5  *  Copyright (C) 2001-2003 Pavel Machek <pavel@ucw.cz>
6  */
7 
8 #include <linux/acpi.h>
9 #include <linux/bootmem.h>
10 #include <linux/memblock.h>
11 #include <linux/dmi.h>
12 #include <linux/cpumask.h>
13 #include <asm/segment.h>
14 #include <asm/desc.h>
15 #include <asm/pgtable.h>
16 #include <asm/cacheflush.h>
17 #include <asm/realmode.h>
18 
19 #include <linux/ftrace.h>
20 #include "../../realmode/rm/wakeup.h"
21 #include "sleep.h"
22 
23 unsigned long acpi_realmode_flags;
24 
25 #if defined(CONFIG_SMP) && defined(CONFIG_64BIT)
26 static char temp_stack[4096];
27 #endif
28 
29 /**
30  * x86_acpi_enter_sleep_state - enter sleep state
31  * @state: Sleep state to enter.
32  *
33  * Wrapper around acpi_enter_sleep_state() to be called by assmebly.
34  */
x86_acpi_enter_sleep_state(u8 state)35 acpi_status asmlinkage __visible x86_acpi_enter_sleep_state(u8 state)
36 {
37 	return acpi_enter_sleep_state(state);
38 }
39 
40 /**
41  * x86_acpi_suspend_lowlevel - save kernel state
42  *
43  * Create an identity mapped page table and copy the wakeup routine to
44  * low memory.
45  */
x86_acpi_suspend_lowlevel(void)46 int x86_acpi_suspend_lowlevel(void)
47 {
48 	struct wakeup_header *header =
49 		(struct wakeup_header *) __va(real_mode_header->wakeup_header);
50 
51 	if (header->signature != WAKEUP_HEADER_SIGNATURE) {
52 		printk(KERN_ERR "wakeup header does not match\n");
53 		return -EINVAL;
54 	}
55 
56 	header->video_mode = saved_video_mode;
57 
58 	header->pmode_behavior = 0;
59 
60 #ifndef CONFIG_64BIT
61 	native_store_gdt((struct desc_ptr *)&header->pmode_gdt);
62 
63 	/*
64 	 * We have to check that we can write back the value, and not
65 	 * just read it.  At least on 90 nm Pentium M (Family 6, Model
66 	 * 13), reading an invalid MSR is not guaranteed to trap, see
67 	 * Erratum X4 in "Intel Pentium M Processor on 90 nm Process
68 	 * with 2-MB L2 Cache and Intel® Processor A100 and A110 on 90
69 	 * nm process with 512-KB L2 Cache Specification Update".
70 	 */
71 	if (!rdmsr_safe(MSR_EFER,
72 			&header->pmode_efer_low,
73 			&header->pmode_efer_high) &&
74 	    !wrmsr_safe(MSR_EFER,
75 			header->pmode_efer_low,
76 			header->pmode_efer_high))
77 		header->pmode_behavior |= (1 << WAKEUP_BEHAVIOR_RESTORE_EFER);
78 #endif /* !CONFIG_64BIT */
79 
80 	header->pmode_cr0 = read_cr0();
81 	if (__this_cpu_read(cpu_info.cpuid_level) >= 0) {
82 		header->pmode_cr4 = __read_cr4();
83 		header->pmode_behavior |= (1 << WAKEUP_BEHAVIOR_RESTORE_CR4);
84 	}
85 	if (!rdmsr_safe(MSR_IA32_MISC_ENABLE,
86 			&header->pmode_misc_en_low,
87 			&header->pmode_misc_en_high) &&
88 	    !wrmsr_safe(MSR_IA32_MISC_ENABLE,
89 			header->pmode_misc_en_low,
90 			header->pmode_misc_en_high))
91 		header->pmode_behavior |=
92 			(1 << WAKEUP_BEHAVIOR_RESTORE_MISC_ENABLE);
93 	header->realmode_flags = acpi_realmode_flags;
94 	header->real_magic = 0x12345678;
95 
96 #ifndef CONFIG_64BIT
97 	header->pmode_entry = (u32)&wakeup_pmode_return;
98 	header->pmode_cr3 = (u32)__pa_symbol(initial_page_table);
99 	saved_magic = 0x12345678;
100 #else /* CONFIG_64BIT */
101 #ifdef CONFIG_SMP
102 	stack_start = (unsigned long)temp_stack + sizeof(temp_stack);
103 	early_gdt_descr.address =
104 			(unsigned long)get_cpu_gdt_table(smp_processor_id());
105 	initial_gs = per_cpu_offset(smp_processor_id());
106 #endif
107 	initial_code = (unsigned long)wakeup_long64;
108        saved_magic = 0x123456789abcdef0L;
109 #endif /* CONFIG_64BIT */
110 
111 	/*
112 	 * Pause/unpause graph tracing around do_suspend_lowlevel as it has
113 	 * inconsistent call/return info after it jumps to the wakeup vector.
114 	 */
115 	pause_graph_tracing();
116 	do_suspend_lowlevel();
117 	unpause_graph_tracing();
118 	return 0;
119 }
120 
acpi_sleep_setup(char * str)121 static int __init acpi_sleep_setup(char *str)
122 {
123 	while ((str != NULL) && (*str != '\0')) {
124 		if (strncmp(str, "s3_bios", 7) == 0)
125 			acpi_realmode_flags |= 1;
126 		if (strncmp(str, "s3_mode", 7) == 0)
127 			acpi_realmode_flags |= 2;
128 		if (strncmp(str, "s3_beep", 7) == 0)
129 			acpi_realmode_flags |= 4;
130 #ifdef CONFIG_HIBERNATION
131 		if (strncmp(str, "s4_nohwsig", 10) == 0)
132 			acpi_no_s4_hw_signature();
133 #endif
134 		if (strncmp(str, "nonvs", 5) == 0)
135 			acpi_nvs_nosave();
136 		if (strncmp(str, "nonvs_s3", 8) == 0)
137 			acpi_nvs_nosave_s3();
138 		if (strncmp(str, "old_ordering", 12) == 0)
139 			acpi_old_suspend_ordering();
140 		str = strchr(str, ',');
141 		if (str != NULL)
142 			str += strspn(str, ", \t");
143 	}
144 	return 1;
145 }
146 
147 __setup("acpi_sleep=", acpi_sleep_setup);
148