| Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame^] | 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); |