xref: /openbmc/linux/arch/x86/kernel/acpi/sleep.c (revision 9ac8d3fb)
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 #include <asm/desc.h>
14 
15 #include "realmode/wakeup.h"
16 #include "sleep.h"
17 
18 unsigned long acpi_wakeup_address;
19 unsigned long acpi_realmode_flags;
20 
21 /* address in low memory of the wakeup routine. */
22 static unsigned long acpi_realmode;
23 
24 #if defined(CONFIG_SMP) && defined(CONFIG_64BIT)
25 static char temp_stack[4096];
26 #endif
27 
28 /**
29  * acpi_save_state_mem - save kernel state
30  *
31  * Create an identity mapped page table and copy the wakeup routine to
32  * low memory.
33  *
34  * Note that this is too late to change acpi_wakeup_address.
35  */
36 int acpi_save_state_mem(void)
37 {
38 	struct wakeup_header *header;
39 
40 	if (!acpi_realmode) {
41 		printk(KERN_ERR "Could not allocate memory during boot, "
42 		       "S3 disabled\n");
43 		return -ENOMEM;
44 	}
45 	memcpy((void *)acpi_realmode, &wakeup_code_start, WAKEUP_SIZE);
46 
47 	header = (struct wakeup_header *)(acpi_realmode + HEADER_OFFSET);
48 	if (header->signature != 0x51ee1111) {
49 		printk(KERN_ERR "wakeup header does not match\n");
50 		return -EINVAL;
51 	}
52 
53 	header->video_mode = saved_video_mode;
54 
55 	header->wakeup_jmp_seg = acpi_wakeup_address >> 4;
56 
57 	/*
58 	 * Set up the wakeup GDT.  We set these up as Big Real Mode,
59 	 * that is, with limits set to 4 GB.  At least the Lenovo
60 	 * Thinkpad X61 is known to need this for the video BIOS
61 	 * initialization quirk to work; this is likely to also
62 	 * be the case for other laptops or integrated video devices.
63 	 */
64 
65 	/* GDT[0]: GDT self-pointer */
66 	header->wakeup_gdt[0] =
67 		(u64)(sizeof(header->wakeup_gdt) - 1) +
68 		((u64)(acpi_wakeup_address +
69 			((char *)&header->wakeup_gdt - (char *)acpi_realmode))
70 				<< 16);
71 	/* GDT[1]: big real mode-like code segment */
72 	header->wakeup_gdt[1] =
73 		GDT_ENTRY(0x809b, acpi_wakeup_address, 0xfffff);
74 	/* GDT[2]: big real mode-like data segment */
75 	header->wakeup_gdt[2] =
76 		GDT_ENTRY(0x8093, acpi_wakeup_address, 0xfffff);
77 
78 #ifndef CONFIG_64BIT
79 	store_gdt((struct desc_ptr *)&header->pmode_gdt);
80 
81 	header->pmode_efer_low = nx_enabled;
82 	if (header->pmode_efer_low & 1) {
83 		/* This is strange, why not save efer, always? */
84 		rdmsr(MSR_EFER, header->pmode_efer_low,
85 			header->pmode_efer_high);
86 	}
87 #endif /* !CONFIG_64BIT */
88 
89 	header->pmode_cr0 = read_cr0();
90 	header->pmode_cr4 = read_cr4_safe();
91 	header->realmode_flags = acpi_realmode_flags;
92 	header->real_magic = 0x12345678;
93 
94 #ifndef CONFIG_64BIT
95 	header->pmode_entry = (u32)&wakeup_pmode_return;
96 	header->pmode_cr3 = (u32)(swsusp_pg_dir - __PAGE_OFFSET);
97 	saved_magic = 0x12345678;
98 #else /* CONFIG_64BIT */
99 	header->trampoline_segment = setup_trampoline() >> 4;
100 #ifdef CONFIG_SMP
101 	stack_start.sp = temp_stack + sizeof(temp_stack);
102 	early_gdt_descr.address =
103 			(unsigned long)get_cpu_gdt_table(smp_processor_id());
104 #endif
105 	initial_code = (unsigned long)wakeup_long64;
106 	saved_magic = 0x123456789abcdef0;
107 #endif /* CONFIG_64BIT */
108 
109 	return 0;
110 }
111 
112 /*
113  * acpi_restore_state - undo effects of acpi_save_state_mem
114  */
115 void acpi_restore_state_mem(void)
116 {
117 }
118 
119 
120 /**
121  * acpi_reserve_bootmem - do _very_ early ACPI initialisation
122  *
123  * We allocate a page from the first 1MB of memory for the wakeup
124  * routine for when we come back from a sleep state. The
125  * runtime allocator allows specification of <16MB pages, but not
126  * <1MB pages.
127  */
128 void __init acpi_reserve_bootmem(void)
129 {
130 	if ((&wakeup_code_end - &wakeup_code_start) > WAKEUP_SIZE) {
131 		printk(KERN_ERR
132 		       "ACPI: Wakeup code way too big, S3 disabled.\n");
133 		return;
134 	}
135 
136 	acpi_realmode = (unsigned long)alloc_bootmem_low(WAKEUP_SIZE);
137 
138 	if (!acpi_realmode) {
139 		printk(KERN_ERR "ACPI: Cannot allocate lowmem, S3 disabled.\n");
140 		return;
141 	}
142 
143 	acpi_wakeup_address = virt_to_phys((void *)acpi_realmode);
144 }
145 
146 
147 static int __init acpi_sleep_setup(char *str)
148 {
149 	while ((str != NULL) && (*str != '\0')) {
150 		if (strncmp(str, "s3_bios", 7) == 0)
151 			acpi_realmode_flags |= 1;
152 		if (strncmp(str, "s3_mode", 7) == 0)
153 			acpi_realmode_flags |= 2;
154 		if (strncmp(str, "s3_beep", 7) == 0)
155 			acpi_realmode_flags |= 4;
156 #ifdef CONFIG_HIBERNATION
157 		if (strncmp(str, "s4_nohwsig", 10) == 0)
158 			acpi_no_s4_hw_signature();
159 #endif
160 		if (strncmp(str, "old_ordering", 12) == 0)
161 			acpi_old_suspend_ordering();
162 		str = strchr(str, ',');
163 		if (str != NULL)
164 			str += strspn(str, ", \t");
165 	}
166 	return 1;
167 }
168 
169 __setup("acpi_sleep=", acpi_sleep_setup);
170