Linux-2.6.12-rc2
[linux-2.6.git] / arch / i386 / 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 <asm/smp.h>
11 #include <asm/tlbflush.h>
12
13 /* address in low memory of the wakeup routine. */
14 unsigned long acpi_wakeup_address = 0;
15 unsigned long acpi_video_flags;
16 extern char wakeup_start, wakeup_end;
17
18 extern void zap_low_mappings(void);
19
20 extern unsigned long FASTCALL(acpi_copy_wakeup_routine(unsigned long));
21
22 static void init_low_mapping(pgd_t *pgd, int pgd_limit)
23 {
24         int pgd_ofs = 0;
25
26         while ((pgd_ofs < pgd_limit) && (pgd_ofs + USER_PTRS_PER_PGD < PTRS_PER_PGD)) {
27                 set_pgd(pgd, *(pgd+USER_PTRS_PER_PGD));
28                 pgd_ofs++, pgd++;
29         }
30         flush_tlb_all();
31 }
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 int acpi_save_state_mem (void)
40 {
41         if (!acpi_wakeup_address)
42                 return 1;
43         init_low_mapping(swapper_pg_dir, USER_PTRS_PER_PGD);
44         memcpy((void *) acpi_wakeup_address, &wakeup_start, &wakeup_end - &wakeup_start);
45         acpi_copy_wakeup_routine(acpi_wakeup_address);
46
47         return 0;
48 }
49
50 /*
51  * acpi_restore_state - undo effects of acpi_save_state_mem
52  */
53 void acpi_restore_state_mem (void)
54 {
55         zap_low_mappings();
56 }
57
58 /**
59  * acpi_reserve_bootmem - do _very_ early ACPI initialisation
60  *
61  * We allocate a page from the first 1MB of memory for the wakeup
62  * routine for when we come back from a sleep state. The
63  * runtime allocator allows specification of <16MB pages, but not
64  * <1MB pages.
65  */
66 void __init acpi_reserve_bootmem(void)
67 {
68         if ((&wakeup_end - &wakeup_start) > PAGE_SIZE) {
69                 printk(KERN_ERR "ACPI: Wakeup code way too big, S3 disabled.\n");
70                 return;
71         }
72
73         acpi_wakeup_address = (unsigned long)alloc_bootmem_low(PAGE_SIZE);
74         if (!acpi_wakeup_address)
75                 printk(KERN_ERR "ACPI: Cannot allocate lowmem, S3 disabled.\n");
76 }
77
78 static int __init acpi_sleep_setup(char *str)
79 {
80         while ((str != NULL) && (*str != '\0')) {
81                 if (strncmp(str, "s3_bios", 7) == 0)
82                         acpi_video_flags = 1;
83                 if (strncmp(str, "s3_mode", 7) == 0)
84                         acpi_video_flags |= 2;
85                 str = strchr(str, ',');
86                 if (str != NULL)
87                         str += strspn(str, ", \t");
88         }
89         return 1;
90 }
91
92
93 __setup("acpi_sleep=", acpi_sleep_setup);