x86 ACPI: normalize segment descriptor register on resume
[linux-3.10.git] / arch / x86 / kernel / acpi / sleep.c
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
13 #include "realmode/wakeup.h"
14 #include "sleep.h"
15
16 unsigned long acpi_wakeup_address;
17 unsigned long acpi_realmode_flags;
18
19 /* address in low memory of the wakeup routine. */
20 static unsigned long acpi_realmode;
21
22 #ifdef CONFIG_64BIT
23 static char temp_stack[10240];
24 #endif
25
26 /**
27  * acpi_save_state_mem - save kernel state
28  *
29  * Create an identity mapped page table and copy the wakeup routine to
30  * low memory.
31  *
32  * Note that this is too late to change acpi_wakeup_address.
33  */
34 int acpi_save_state_mem(void)
35 {
36         struct wakeup_header *header;
37
38         if (!acpi_realmode) {
39                 printk(KERN_ERR "Could not allocate memory during boot, "
40                        "S3 disabled\n");
41                 return -ENOMEM;
42         }
43         memcpy((void *)acpi_realmode, &wakeup_code_start, WAKEUP_SIZE);
44
45         header = (struct wakeup_header *)(acpi_realmode + HEADER_OFFSET);
46         if (header->signature != 0x51ee1111) {
47                 printk(KERN_ERR "wakeup header does not match\n");
48                 return -EINVAL;
49         }
50
51         header->video_mode = saved_video_mode;
52
53         header->wakeup_jmp_seg = acpi_wakeup_address >> 4;
54         /* GDT[0]: GDT self-pointer */
55         header->wakeup_gdt[0] =
56                 (u64)(sizeof(header->wakeup_gdt) - 1) +
57                 ((u64)(acpi_wakeup_address +
58                         ((char *)&header->wakeup_gdt - (char *)acpi_realmode))
59                                 << 16);
60         /* GDT[1]: real-mode-like code segment */
61         header->wakeup_gdt[1] = (0x009bULL << 40) +
62                 ((u64)acpi_wakeup_address << 16) + 0xffff;
63         /* GDT[2]: real-mode-like data segment */
64         header->wakeup_gdt[2] = (0x0093ULL << 40) +
65                 ((u64)acpi_wakeup_address << 16) + 0xffff;
66
67 #ifndef CONFIG_64BIT
68         store_gdt((struct desc_ptr *)&header->pmode_gdt);
69
70         header->pmode_efer_low = nx_enabled;
71         if (header->pmode_efer_low & 1) {
72                 /* This is strange, why not save efer, always? */
73                 rdmsr(MSR_EFER, header->pmode_efer_low,
74                         header->pmode_efer_high);
75         }
76 #endif /* !CONFIG_64BIT */
77
78         header->pmode_cr0 = read_cr0();
79         header->pmode_cr4 = read_cr4();
80         header->realmode_flags = acpi_realmode_flags;
81         header->real_magic = 0x12345678;
82
83 #ifndef CONFIG_64BIT
84         header->pmode_entry = (u32)&wakeup_pmode_return;
85         header->pmode_cr3 = (u32)(swsusp_pg_dir - __PAGE_OFFSET);
86         saved_magic = 0x12345678;
87 #else /* CONFIG_64BIT */
88         header->trampoline_segment = setup_trampoline() >> 4;
89         init_rsp = (unsigned long)temp_stack + 4096;
90         initial_code = (unsigned long)wakeup_long64;
91         saved_magic = 0x123456789abcdef0;
92 #endif /* CONFIG_64BIT */
93
94         return 0;
95 }
96
97 /*
98  * acpi_restore_state - undo effects of acpi_save_state_mem
99  */
100 void acpi_restore_state_mem(void)
101 {
102 }
103
104
105 /**
106  * acpi_reserve_bootmem - do _very_ early ACPI initialisation
107  *
108  * We allocate a page from the first 1MB of memory for the wakeup
109  * routine for when we come back from a sleep state. The
110  * runtime allocator allows specification of <16MB pages, but not
111  * <1MB pages.
112  */
113 void __init acpi_reserve_bootmem(void)
114 {
115         if ((&wakeup_code_end - &wakeup_code_start) > WAKEUP_SIZE) {
116                 printk(KERN_ERR
117                        "ACPI: Wakeup code way too big, S3 disabled.\n");
118                 return;
119         }
120
121         acpi_realmode = (unsigned long)alloc_bootmem_low(WAKEUP_SIZE);
122
123         if (!acpi_realmode) {
124                 printk(KERN_ERR "ACPI: Cannot allocate lowmem, S3 disabled.\n");
125                 return;
126         }
127
128         acpi_wakeup_address = virt_to_phys((void *)acpi_realmode);
129 }
130
131
132 static int __init acpi_sleep_setup(char *str)
133 {
134         while ((str != NULL) && (*str != '\0')) {
135                 if (strncmp(str, "s3_bios", 7) == 0)
136                         acpi_realmode_flags |= 1;
137                 if (strncmp(str, "s3_mode", 7) == 0)
138                         acpi_realmode_flags |= 2;
139                 if (strncmp(str, "s3_beep", 7) == 0)
140                         acpi_realmode_flags |= 4;
141                 str = strchr(str, ',');
142                 if (str != NULL)
143                         str += strspn(str, ", \t");
144         }
145         return 1;
146 }
147
148 __setup("acpi_sleep=", acpi_sleep_setup);