arch/x86/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 <linux/dmi.h>
  11 #include <linux/cpumask.h>
  12
  13 #include <asm/smp.h>
  14
  15 /* address in low memory of the wakeup routine. */
  16 unsigned long acpi_wakeup_address = 0;
  17 unsigned long acpi_realmode_flags;
  18 extern char wakeup_start, wakeup_end;
  19
  20 extern unsigned long acpi_copy_wakeup_routine(unsigned long);
  21
  22 /**
  23  * acpi_save_state_mem - save kernel state
  24  *
  25  * Create an identity mapped page table and copy the wakeup routine to
  26  * low memory.
  27  */
  28 int acpi_save_state_mem(void)
  29 {
  30         if (!acpi_wakeup_address) {
  31                 printk(KERN_ERR "Could not allocate memory during boot, S3 disabled\n");
  32                 return -ENOMEM;
  33         }
  34         memcpy((void *)acpi_wakeup_address, &wakeup_start,
  35                &wakeup_end - &wakeup_start);
  36         acpi_copy_wakeup_routine(acpi_wakeup_address);
  37
  38         return 0;
  39 }
  40
  41 /*
  42  * acpi_restore_state - undo effects of acpi_save_state_mem
  43  */
  44 void acpi_restore_state_mem(void)
  45 {
  46 }
  47
  48
  49 /**
  50  * acpi_reserve_bootmem - do _very_ early ACPI initialisation
  51  *
  52  * We allocate a page from the first 1MB of memory for the wakeup
  53  * routine for when we come back from a sleep state. The
  54  * runtime allocator allows specification of <16MB pages, but not
  55  * <1MB pages.
  56  */
  57 void __init acpi_reserve_bootmem(void)
  58 {
  59         if ((&wakeup_end - &wakeup_start) > PAGE_SIZE*2) {
  60                 printk(KERN_ERR
  61                        "ACPI: Wakeup code way too big, S3 disabled.\n");
  62                 return;
  63         }
  64
  65         acpi_wakeup_address = (unsigned long)alloc_bootmem_low(PAGE_SIZE*2);
  66         if (!acpi_wakeup_address)
  67                 printk(KERN_ERR "ACPI: Cannot allocate lowmem, S3 disabled.\n");
  68 }
  69
  70
  71 static int __init acpi_sleep_setup(char *str)
  72 {
  73         while ((str != NULL) && (*str != '\0')) {
  74                 if (strncmp(str, "s3_bios", 7) == 0)
  75                         acpi_realmode_flags |= 1;
  76                 if (strncmp(str, "s3_mode", 7) == 0)
  77                         acpi_realmode_flags |= 2;
  78                 if (strncmp(str, "s3_beep", 7) == 0)
  79                         acpi_realmode_flags |= 4;
  80                 str = strchr(str, ',');
  81                 if (str != NULL)
  82                         str += strspn(str, ", \t");
  83         }
  84         return 1;
  85 }
  86
  87 __setup("acpi_sleep=", acpi_sleep_setup);