xref: /openbmc/linux/arch/x86/kernel/acpi/sleep.c (revision 94cdda6b)
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 "../../realmode/rm/wakeup.h"
20 #include "sleep.h"
21 
22 unsigned long acpi_realmode_flags;
23 
24 #if defined(CONFIG_SMP) && defined(CONFIG_64BIT)
25 static char temp_stack[4096];
26 #endif
27 
28 /**
29  * x86_acpi_enter_sleep_state - enter sleep state
30  * @state: Sleep state to enter.
31  *
32  * Wrapper around acpi_enter_sleep_state() to be called by assmebly.
33  */
34 acpi_status asmlinkage __visible x86_acpi_enter_sleep_state(u8 state)
35 {
36 	return acpi_enter_sleep_state(state);
37 }
38 
39 /**
40  * x86_acpi_suspend_lowlevel - save kernel state
41  *
42  * Create an identity mapped page table and copy the wakeup routine to
43  * low memory.
44  */
45 int x86_acpi_suspend_lowlevel(void)
46 {
47 	struct wakeup_header *header =
48 		(struct wakeup_header *) __va(real_mode_header->wakeup_header);
49 
50 	if (header->signature != WAKEUP_HEADER_SIGNATURE) {
51 		printk(KERN_ERR "wakeup header does not match\n");
52 		return -EINVAL;
53 	}
54 
55 	header->video_mode = saved_video_mode;
56 
57 	header->pmode_behavior = 0;
58 
59 #ifndef CONFIG_64BIT
60 	native_store_gdt((struct desc_ptr *)&header->pmode_gdt);
61 
62 	/*
63 	 * We have to check that we can write back the value, and not
64 	 * just read it.  At least on 90 nm Pentium M (Family 6, Model
65 	 * 13), reading an invalid MSR is not guaranteed to trap, see
66 	 * Erratum X4 in "Intel Pentium M Processor on 90 nm Process
67 	 * with 2-MB L2 Cache and Intel® Processor A100 and A110 on 90
68 	 * nm process with 512-KB L2 Cache Specification Update".
69 	 */
70 	if (!rdmsr_safe(MSR_EFER,
71 			&header->pmode_efer_low,
72 			&header->pmode_efer_high) &&
73 	    !wrmsr_safe(MSR_EFER,
74 			header->pmode_efer_low,
75 			header->pmode_efer_high))
76 		header->pmode_behavior |= (1 << WAKEUP_BEHAVIOR_RESTORE_EFER);
77 #endif /* !CONFIG_64BIT */
78 
79 	header->pmode_cr0 = read_cr0();
80 	if (__this_cpu_read(cpu_info.cpuid_level) >= 0) {
81 		header->pmode_cr4 = __read_cr4();
82 		header->pmode_behavior |= (1 << WAKEUP_BEHAVIOR_RESTORE_CR4);
83 	}
84 	if (!rdmsr_safe(MSR_IA32_MISC_ENABLE,
85 			&header->pmode_misc_en_low,
86 			&header->pmode_misc_en_high) &&
87 	    !wrmsr_safe(MSR_IA32_MISC_ENABLE,
88 			header->pmode_misc_en_low,
89 			header->pmode_misc_en_high))
90 		header->pmode_behavior |=
91 			(1 << WAKEUP_BEHAVIOR_RESTORE_MISC_ENABLE);
92 	header->realmode_flags = acpi_realmode_flags;
93 	header->real_magic = 0x12345678;
94 
95 #ifndef CONFIG_64BIT
96 	header->pmode_entry = (u32)&wakeup_pmode_return;
97 	header->pmode_cr3 = (u32)__pa_symbol(initial_page_table);
98 	saved_magic = 0x12345678;
99 #else /* CONFIG_64BIT */
100 #ifdef CONFIG_SMP
101 	stack_start = (unsigned long)temp_stack + sizeof(temp_stack);
102 	early_gdt_descr.address =
103 			(unsigned long)get_cpu_gdt_table(smp_processor_id());
104 	initial_gs = per_cpu_offset(smp_processor_id());
105 #endif
106 	initial_code = (unsigned long)wakeup_long64;
107        saved_magic = 0x123456789abcdef0L;
108 #endif /* CONFIG_64BIT */
109 
110 	do_suspend_lowlevel();
111 	return 0;
112 }
113 
114 static int __init acpi_sleep_setup(char *str)
115 {
116 	while ((str != NULL) && (*str != '\0')) {
117 		if (strncmp(str, "s3_bios", 7) == 0)
118 			acpi_realmode_flags |= 1;
119 		if (strncmp(str, "s3_mode", 7) == 0)
120 			acpi_realmode_flags |= 2;
121 		if (strncmp(str, "s3_beep", 7) == 0)
122 			acpi_realmode_flags |= 4;
123 #ifdef CONFIG_HIBERNATION
124 		if (strncmp(str, "s4_nohwsig", 10) == 0)
125 			acpi_no_s4_hw_signature();
126 #endif
127 		if (strncmp(str, "nonvs", 5) == 0)
128 			acpi_nvs_nosave();
129 		if (strncmp(str, "nonvs_s3", 8) == 0)
130 			acpi_nvs_nosave_s3();
131 		if (strncmp(str, "old_ordering", 12) == 0)
132 			acpi_old_suspend_ordering();
133 		str = strchr(str, ',');
134 		if (str != NULL)
135 			str += strspn(str, ", \t");
136 	}
137 	return 1;
138 }
139 
140 __setup("acpi_sleep=", acpi_sleep_setup);
141