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 map_low(pgd_t *pgd_base, unsigned long start, unsigned long end)
  23 {
  24         unsigned long vaddr;
  25         pmd_t *pmd;
  26         pgd_t *pgd;
  27         int i, j;
  28
  29         pgd = pgd_base;
  30
  31         for (i = 0; i < PTRS_PER_PGD; pgd++, i++) {
  32                 vaddr = i*PGDIR_SIZE;
  33                 if (end && (vaddr >= end))
  34                         break;
  35                 pmd = pmd_offset(pgd, 0);
  36                 for (j = 0; j < PTRS_PER_PMD; pmd++, j++) {
  37                         vaddr = i*PGDIR_SIZE + j*PMD_SIZE;
  38                         if (end && (vaddr >= end))
  39                                 break;
  40                         if (vaddr < start)
  41                                 continue;
  42                         set_pmd(pmd, __pmd(_KERNPG_TABLE + _PAGE_PSE +
  43                                                                 vaddr - start));
  44                 }
  45         }
  46 }
  47
  48 /**
  49  * acpi_save_state_mem - save kernel state
  50  *
  51  * Create an identity mapped page table and copy the wakeup routine to
  52  * low memory.
  53  */
  54 int acpi_save_state_mem (void)
  55 {
  56         if (!acpi_wakeup_address)
  57                 return 1;
  58         if (!cpu_has_pse)
  59                 return 1;
  60         map_low(swapper_pg_dir, 0, LOW_MAPPINGS_SIZE);
  61         memcpy((void *) acpi_wakeup_address, &wakeup_start, &wakeup_end - &wakeup_start);
  62         acpi_copy_wakeup_routine(acpi_wakeup_address);
  63
  64         return 0;
  65 }
  66
  67 /**
  68  * acpi_save_state_disk - save kernel state to disk
  69  *
  70  */
  71 int acpi_save_state_disk (void)
  72 {
  73         return 1;
  74 }
  75
  76 /*
  77  * acpi_restore_state
  78  */
  79 void acpi_restore_state_mem (void)
  80 {
  81         zap_low_mappings();
  82 }
  83
  84 /**
  85  * acpi_reserve_bootmem - do _very_ early ACPI initialisation
  86  *
  87  * We allocate a page from the first 1MB of memory for the wakeup
  88  * routine for when we come back from a sleep state. The
  89  * runtime allocator allows specification of <16MB pages, but not
  90  * <1MB pages.
  91  */
  92 void __init acpi_reserve_bootmem(void)
  93 {
  94         if ((&wakeup_end - &wakeup_start) > PAGE_SIZE) {
  95                 printk(KERN_ERR "ACPI: Wakeup code way too big, S3 disabled.\n");
  96                 return;
  97         }
  98 #ifdef CONFIG_X86_PAE
  99         printk(KERN_ERR "ACPI: S3 and PAE do not like each other for now, S3 disabled.\n");
 100         return;
 101 #endif
 102         acpi_wakeup_address = (unsigned long)alloc_bootmem_low(PAGE_SIZE);
 103         if (!acpi_wakeup_address)
 104                 printk(KERN_ERR "ACPI: Cannot allocate lowmem, S3 disabled.\n");
 105 }
 106
 107 static int __init acpi_sleep_setup(char *str)
 108 {
 109         while ((str != NULL) && (*str != '\0')) {
 110                 if (strncmp(str, "s3_bios", 7) == 0)
 111                         acpi_video_flags = 1;
 112                 if (strncmp(str, "s3_mode", 7) == 0)
 113                         acpi_video_flags |= 2;
 114                 str = strchr(str, ',');
 115                 if (str != NULL)
 116                         str += strspn(str, ", \t");
 117         }
 118         return 1;
 119 }
 120
 121
 122 __setup("acpi_sleep=", acpi_sleep_setup);