xref: /openbmc/linux/arch/x86/kernel/acpi/sleep.c (revision f15cbe6f1a4b4d9df59142fc8e4abb973302cf44)
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@suse.cz>
6  */
7 
8 #include <linux/acpi.h>
9 #include <linux/bootmem.h>
10 #include <linux/dmi.h>
11 #include <linux/cpumask.h>
12 #include <asm/segment.h>
13 
14 #include "realmode/wakeup.h"
15 #include "sleep.h"
16 
17 unsigned long acpi_wakeup_address;
18 unsigned long acpi_realmode_flags;
19 
20 /* address in low memory of the wakeup routine. */
21 static unsigned long acpi_realmode;
22 
23 #ifdef CONFIG_64BIT
24 static char temp_stack[10240];
25 #endif
26 
27 /**
28  * acpi_save_state_mem - save kernel state
29  *
30  * Create an identity mapped page table and copy the wakeup routine to
31  * low memory.
32  *
33  * Note that this is too late to change acpi_wakeup_address.
34  */
35 int acpi_save_state_mem(void)
36 {
37 	struct wakeup_header *header;
38 
39 	if (!acpi_realmode) {
40 		printk(KERN_ERR "Could not allocate memory during boot, "
41 		       "S3 disabled\n");
42 		return -ENOMEM;
43 	}
44 	memcpy((void *)acpi_realmode, &wakeup_code_start, WAKEUP_SIZE);
45 
46 	header = (struct wakeup_header *)(acpi_realmode + HEADER_OFFSET);
47 	if (header->signature != 0x51ee1111) {
48 		printk(KERN_ERR "wakeup header does not match\n");
49 		return -EINVAL;
50 	}
51 
52 	header->video_mode = saved_video_mode;
53 
54 	header->wakeup_jmp_seg = acpi_wakeup_address >> 4;
55 
56 	/*
57 	 * Set up the wakeup GDT.  We set these up as Big Real Mode,
58 	 * that is, with limits set to 4 GB.  At least the Lenovo
59 	 * Thinkpad X61 is known to need this for the video BIOS
60 	 * initialization quirk to work; this is likely to also
61 	 * be the case for other laptops or integrated video devices.
62 	 */
63 
64 	/* GDT[0]: GDT self-pointer */
65 	header->wakeup_gdt[0] =
66 		(u64)(sizeof(header->wakeup_gdt) - 1) +
67 		((u64)(acpi_wakeup_address +
68 			((char *)&header->wakeup_gdt - (char *)acpi_realmode))
69 				<< 16);
70 	/* GDT[1]: big real mode-like code segment */
71 	header->wakeup_gdt[1] =
72 		GDT_ENTRY(0x809b, acpi_wakeup_address, 0xfffff);
73 	/* GDT[2]: big real mode-like data segment */
74 	header->wakeup_gdt[2] =
75 		GDT_ENTRY(0x8093, acpi_wakeup_address, 0xfffff);
76 
77 #ifndef CONFIG_64BIT
78 	store_gdt((struct desc_ptr *)&header->pmode_gdt);
79 
80 	header->pmode_efer_low = nx_enabled;
81 	if (header->pmode_efer_low & 1) {
82 		/* This is strange, why not save efer, always? */
83 		rdmsr(MSR_EFER, header->pmode_efer_low,
84 			header->pmode_efer_high);
85 	}
86 #endif /* !CONFIG_64BIT */
87 
88 	header->pmode_cr0 = read_cr0();
89 	header->pmode_cr4 = read_cr4();
90 	header->realmode_flags = acpi_realmode_flags;
91 	header->real_magic = 0x12345678;
92 
93 #ifndef CONFIG_64BIT
94 	header->pmode_entry = (u32)&wakeup_pmode_return;
95 	header->pmode_cr3 = (u32)(swsusp_pg_dir - __PAGE_OFFSET);
96 	saved_magic = 0x12345678;
97 #else /* CONFIG_64BIT */
98 	header->trampoline_segment = setup_trampoline() >> 4;
99 #ifdef CONFIG_SMP
100 	stack_start.sp = temp_stack + 4096;
101 #endif
102 	initial_code = (unsigned long)wakeup_long64;
103 	saved_magic = 0x123456789abcdef0;
104 #endif /* CONFIG_64BIT */
105 
106 	return 0;
107 }
108 
109 /*
110  * acpi_restore_state - undo effects of acpi_save_state_mem
111  */
112 void acpi_restore_state_mem(void)
113 {
114 }
115 
116 
117 /**
118  * acpi_reserve_bootmem - do _very_ early ACPI initialisation
119  *
120  * We allocate a page from the first 1MB of memory for the wakeup
121  * routine for when we come back from a sleep state. The
122  * runtime allocator allows specification of <16MB pages, but not
123  * <1MB pages.
124  */
125 void __init acpi_reserve_bootmem(void)
126 {
127 	if ((&wakeup_code_end - &wakeup_code_start) > WAKEUP_SIZE) {
128 		printk(KERN_ERR
129 		       "ACPI: Wakeup code way too big, S3 disabled.\n");
130 		return;
131 	}
132 
133 	acpi_realmode = (unsigned long)alloc_bootmem_low(WAKEUP_SIZE);
134 
135 	if (!acpi_realmode) {
136 		printk(KERN_ERR "ACPI: Cannot allocate lowmem, S3 disabled.\n");
137 		return;
138 	}
139 
140 	acpi_wakeup_address = virt_to_phys((void *)acpi_realmode);
141 }
142 
143 
144 static int __init acpi_sleep_setup(char *str)
145 {
146 	while ((str != NULL) && (*str != '\0')) {
147 		if (strncmp(str, "s3_bios", 7) == 0)
148 			acpi_realmode_flags |= 1;
149 		if (strncmp(str, "s3_mode", 7) == 0)
150 			acpi_realmode_flags |= 2;
151 		if (strncmp(str, "s3_beep", 7) == 0)
152 			acpi_realmode_flags |= 4;
153 #ifdef CONFIG_HIBERNATION
154 		if (strncmp(str, "s4_nohwsig", 10) == 0)
155 			acpi_no_s4_hw_signature();
156 #endif
157 		if (strncmp(str, "old_ordering", 12) == 0)
158 			acpi_old_suspend_ordering();
159 		str = strchr(str, ',');
160 		if (str != NULL)
161 			str += strspn(str, ", \t");
162 	}
163 	return 1;
164 }
165 
166 __setup("acpi_sleep=", acpi_sleep_setup);
167