2 * sleep.c - x86-specific ACPI sleep support.
4 * Copyright (C) 2001-2003 Patrick Mochel
5 * Copyright (C) 2001-2003 Pavel Machek <pavel@suse.cz>
8 #include <linux/acpi.h>
9 #include <linux/bootmem.h>
11 #include <asm/tlbflush.h>
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;
18 extern void zap_low_mappings(void);
20 extern unsigned long FASTCALL(acpi_copy_wakeup_routine(unsigned long));
22 static void init_low_mapping(pgd_t *pgd, int pgd_limit)
26 while ((pgd_ofs < pgd_limit) && (pgd_ofs + USER_PTRS_PER_PGD < PTRS_PER_PGD)) {
27 set_pgd(pgd, *(pgd+USER_PTRS_PER_PGD));
34 * acpi_save_state_mem - save kernel state
36 * Create an identity mapped page table and copy the wakeup routine to
39 int acpi_save_state_mem (void)
41 if (!acpi_wakeup_address)
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);
51 * acpi_restore_state - undo effects of acpi_save_state_mem
53 void acpi_restore_state_mem (void)
59 * acpi_reserve_bootmem - do _very_ early ACPI initialisation
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
66 void __init acpi_reserve_bootmem(void)
68 if ((&wakeup_end - &wakeup_start) > PAGE_SIZE) {
69 printk(KERN_ERR "ACPI: Wakeup code way too big, S3 disabled.\n");
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");
78 static int __init acpi_sleep_setup(char *str)
80 while ((str != NULL) && (*str != '\0')) {
81 if (strncmp(str, "s3_bios", 7) == 0)
83 if (strncmp(str, "s3_mode", 7) == 0)
84 acpi_video_flags |= 2;
85 str = strchr(str, ',');
87 str += strspn(str, ", \t");
93 __setup("acpi_sleep=", acpi_sleep_setup);