/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. */
14unsigned long acpi_wakeup_address = 0;
15unsigned long acpi_video_flags;
16extern char wakeup_start, wakeup_end;
17
18extern void zap_low_mappings(void);
19
20extern unsigned long FASTCALL(acpi_copy_wakeup_routine(unsigned long));
21
22static 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 */
39int 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 */
53void 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 */
66void __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
78static 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);