xref: /openbmc/linux/arch/x86/kernel/acpi/sleep.c (revision baa7eb025ab14f3cba2e35c0a8648f9c9f01d24f)
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 
16 #ifdef CONFIG_X86_32
17 #include <asm/pgtable.h>
18 #endif
19 
20 #include "realmode/wakeup.h"
21 #include "sleep.h"
22 
23 unsigned long acpi_wakeup_address;
24 unsigned long acpi_realmode_flags;
25 
26 /* address in low memory of the wakeup routine. */
27 static unsigned long acpi_realmode;
28 
29 #if defined(CONFIG_SMP) && defined(CONFIG_64BIT)
30 static char temp_stack[4096];
31 #endif
32 
33 /**
34  * acpi_save_state_mem - save kernel state
35  *
36  * Create an identity mapped page table and copy the wakeup routine to
37  * low memory.
38  *
39  * Note that this is too late to change acpi_wakeup_address.
40  */
41 int acpi_save_state_mem(void)
42 {
43 	struct wakeup_header *header;
44 
45 	if (!acpi_realmode) {
46 		printk(KERN_ERR "Could not allocate memory during boot, "
47 		       "S3 disabled\n");
48 		return -ENOMEM;
49 	}
50 	memcpy((void *)acpi_realmode, &wakeup_code_start, WAKEUP_SIZE);
51 
52 	header = (struct wakeup_header *)(acpi_realmode + HEADER_OFFSET);
53 	if (header->signature != 0x51ee1111) {
54 		printk(KERN_ERR "wakeup header does not match\n");
55 		return -EINVAL;
56 	}
57 
58 	header->video_mode = saved_video_mode;
59 
60 	header->wakeup_jmp_seg = acpi_wakeup_address >> 4;
61 
62 	/*
63 	 * Set up the wakeup GDT.  We set these up as Big Real Mode,
64 	 * that is, with limits set to 4 GB.  At least the Lenovo
65 	 * Thinkpad X61 is known to need this for the video BIOS
66 	 * initialization quirk to work; this is likely to also
67 	 * be the case for other laptops or integrated video devices.
68 	 */
69 
70 	/* GDT[0]: GDT self-pointer */
71 	header->wakeup_gdt[0] =
72 		(u64)(sizeof(header->wakeup_gdt) - 1) +
73 		((u64)(acpi_wakeup_address +
74 			((char *)&header->wakeup_gdt - (char *)acpi_realmode))
75 				<< 16);
76 	/* GDT[1]: big real mode-like code segment */
77 	header->wakeup_gdt[1] =
78 		GDT_ENTRY(0x809b, acpi_wakeup_address, 0xfffff);
79 	/* GDT[2]: big real mode-like data segment */
80 	header->wakeup_gdt[2] =
81 		GDT_ENTRY(0x8093, acpi_wakeup_address, 0xfffff);
82 
83 #ifndef CONFIG_64BIT
84 	store_gdt((struct desc_ptr *)&header->pmode_gdt);
85 
86 	if (rdmsr_safe(MSR_EFER, &header->pmode_efer_low,
87 		       &header->pmode_efer_high))
88 		header->pmode_efer_low = header->pmode_efer_high = 0;
89 #endif /* !CONFIG_64BIT */
90 
91 	header->pmode_cr0 = read_cr0();
92 	header->pmode_cr4 = read_cr4_safe();
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(&initial_page_table);
99 	saved_magic = 0x12345678;
100 #else /* CONFIG_64BIT */
101 	header->trampoline_segment = setup_trampoline() >> 4;
102 #ifdef CONFIG_SMP
103 	stack_start.sp = temp_stack + sizeof(temp_stack);
104 	early_gdt_descr.address =
105 			(unsigned long)get_cpu_gdt_table(smp_processor_id());
106 	initial_gs = per_cpu_offset(smp_processor_id());
107 #endif
108 	initial_code = (unsigned long)wakeup_long64;
109        saved_magic = 0x123456789abcdef0L;
110 #endif /* CONFIG_64BIT */
111 
112 	return 0;
113 }
114 
115 /*
116  * acpi_restore_state - undo effects of acpi_save_state_mem
117  */
118 void acpi_restore_state_mem(void)
119 {
120 }
121 
122 
123 /**
124  * acpi_reserve_wakeup_memory - do _very_ early ACPI initialisation
125  *
126  * We allocate a page from the first 1MB of memory for the wakeup
127  * routine for when we come back from a sleep state. The
128  * runtime allocator allows specification of <16MB pages, but not
129  * <1MB pages.
130  */
131 void __init acpi_reserve_wakeup_memory(void)
132 {
133 	phys_addr_t mem;
134 
135 	if ((&wakeup_code_end - &wakeup_code_start) > WAKEUP_SIZE) {
136 		printk(KERN_ERR
137 		       "ACPI: Wakeup code way too big, S3 disabled.\n");
138 		return;
139 	}
140 
141 	mem = memblock_find_in_range(0, 1<<20, WAKEUP_SIZE, PAGE_SIZE);
142 
143 	if (mem == MEMBLOCK_ERROR) {
144 		printk(KERN_ERR "ACPI: Cannot allocate lowmem, S3 disabled.\n");
145 		return;
146 	}
147 	acpi_realmode = (unsigned long) phys_to_virt(mem);
148 	acpi_wakeup_address = mem;
149 	memblock_x86_reserve_range(mem, mem + WAKEUP_SIZE, "ACPI WAKEUP");
150 }
151 
152 
153 static int __init acpi_sleep_setup(char *str)
154 {
155 	while ((str != NULL) && (*str != '\0')) {
156 		if (strncmp(str, "s3_bios", 7) == 0)
157 			acpi_realmode_flags |= 1;
158 		if (strncmp(str, "s3_mode", 7) == 0)
159 			acpi_realmode_flags |= 2;
160 		if (strncmp(str, "s3_beep", 7) == 0)
161 			acpi_realmode_flags |= 4;
162 #ifdef CONFIG_HIBERNATION
163 		if (strncmp(str, "s4_nohwsig", 10) == 0)
164 			acpi_no_s4_hw_signature();
165 		if (strncmp(str, "s4_nonvs", 8) == 0) {
166 			pr_warning("ACPI: acpi_sleep=s4_nonvs is deprecated, "
167 					"please use acpi_sleep=nonvs instead");
168 			acpi_nvs_nosave();
169 		}
170 #endif
171 		if (strncmp(str, "nonvs", 5) == 0)
172 			acpi_nvs_nosave();
173 		if (strncmp(str, "old_ordering", 12) == 0)
174 			acpi_old_suspend_ordering();
175 		str = strchr(str, ',');
176 		if (str != NULL)
177 			str += strspn(str, ", \t");
178 	}
179 	return 1;
180 }
181 
182 __setup("acpi_sleep=", acpi_sleep_setup);
183