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
  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 }
  31
  32 /**
  33  * acpi_save_state_mem - save kernel state
  34  *
  35  * Create an identity mapped page table and copy the wakeup routine to
  36  * low memory.
  37  */
  38 int acpi_save_state_mem (void)
  39 {
  40         if (!acpi_wakeup_address)
  41                 return 1;
  42         init_low_mapping(swapper_pg_dir, USER_PTRS_PER_PGD);
  43         memcpy((void *) acpi_wakeup_address, &wakeup_start, &wakeup_end - &wakeup_start);
  44         acpi_copy_wakeup_routine(acpi_wakeup_address);
  45
  46         return 0;
  47 }
  48
  49 /**
  50  * acpi_save_state_disk - save kernel state to disk
  51  *
  52  */
  53 int acpi_save_state_disk (void)
  54 {
  55         return 1;
  56 }
  57
  58 /*
  59  * acpi_restore_state
  60  */
  61 void acpi_restore_state_mem (void)
  62 {
  63         zap_low_mappings();
  64 }
  65
  66 /**
  67  * acpi_reserve_bootmem - do _very_ early ACPI initialisation
  68  *
  69  * We allocate a page from the first 1MB of memory for the wakeup
  70  * routine for when we come back from a sleep state. The
  71  * runtime allocator allows specification of <16MB pages, but not
  72  * <1MB pages.
  73  */
  74 void __init acpi_reserve_bootmem(void)
  75 {
  76         if ((&wakeup_end - &wakeup_start) > PAGE_SIZE) {
  77                 printk(KERN_ERR "ACPI: Wakeup code way too big, S3 disabled.\n");
  78                 return;
  79         }
  80
  81         acpi_wakeup_address = (unsigned long)alloc_bootmem_low(PAGE_SIZE);
  82         if (!acpi_wakeup_address)
  83                 printk(KERN_ERR "ACPI: Cannot allocate lowmem, S3 disabled.\n");
  84 }
  85
  86 static int __init acpi_sleep_setup(char *str)
  87 {
  88         while ((str != NULL) && (*str != '\0')) {
  89                 if (strncmp(str, "s3_bios", 7) == 0)
  90                         acpi_video_flags = 1;
  91                 if (strncmp(str, "s3_mode", 7) == 0)
  92                         acpi_video_flags |= 2;
  93                 str = strchr(str, ',');
  94                 if (str != NULL)
  95                         str += strspn(str, ", \t");
  96         }
  97         return 1;
  98 }
  99
 100
 101 __setup("acpi_sleep=", acpi_sleep_setup);