arch/x86_64/kernel/acpi/sleep.c

   1 /*
   2  *  acpi.c - Architecture-Specific Low-Level ACPI Support
   3  *
   4  *  Copyright (C) 2001, 2002 Paul Diefenbaugh <paul.s.diefenbaugh@intel.com>
   5  *  Copyright (C) 2001 Jun Nakajima <jun.nakajima@intel.com>
   6  *  Copyright (C) 2001 Patrick Mochel <mochel@osdl.org>
   7  *  Copyright (C) 2002 Andi Kleen, SuSE Labs (x86-64 port)
   8  *  Copyright (C) 2003 Pavel Machek, SuSE Labs
   9  *
  10  * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
  11  *
  12  *  This program is free software; you can redistribute it and/or modify
  13  *  it under the terms of the GNU General Public License as published by
  14  *  the Free Software Foundation; either version 2 of the License, or
  15  *  (at your option) any later version.
  16  *
  17  *  This program is distributed in the hope that it will be useful,
  18  *  but WITHOUT ANY WARRANTY; without even the implied warranty of
  19  *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  20  *  GNU General Public License for more details.
  21  *
  22  *  You should have received a copy of the GNU General Public License
  23  *  along with this program; if not, write to the Free Software
  24  *  Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
  25  *
  26  * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
  27  */
  28
  29 #include <linux/config.h>
  30 #include <linux/kernel.h>
  31 #include <linux/init.h>
  32 #include <linux/types.h>
  33 #include <linux/stddef.h>
  34 #include <linux/slab.h>
  35 #include <linux/pci.h>
  36 #include <linux/bootmem.h>
  37 #include <linux/acpi.h>
  38 #include <asm/mpspec.h>
  39 #include <asm/io.h>
  40 #include <asm/apic.h>
  41 #include <asm/apicdef.h>
  42 #include <asm/page.h>
  43 #include <asm/pgtable.h>
  44 #include <asm/pgalloc.h>
  45 #include <asm/io_apic.h>
  46 #include <asm/proto.h>
  47 #include <asm/tlbflush.h>
  48
  49 /* --------------------------------------------------------------------------
  50                               Low-Level Sleep Support
  51    -------------------------------------------------------------------------- */
  52
  53 #ifdef CONFIG_ACPI_SLEEP
  54
  55 /* address in low memory of the wakeup routine. */
  56 unsigned long acpi_wakeup_address = 0;
  57 unsigned long acpi_video_flags;
  58 extern char wakeup_start, wakeup_end;
  59
  60 extern unsigned long FASTCALL(acpi_copy_wakeup_routine(unsigned long));
  61
  62 static pgd_t low_ptr;
  63
  64 static void init_low_mapping(void)
  65 {
  66         pgd_t *slot0 = pgd_offset(current->mm, 0UL);
  67         low_ptr = *slot0;
  68         set_pgd(slot0, *pgd_offset(current->mm, PAGE_OFFSET));
  69         flush_tlb_all();
  70 }
  71
  72 /**
  73  * acpi_save_state_mem - save kernel state
  74  *
  75  * Create an identity mapped page table and copy the wakeup routine to
  76  * low memory.
  77  */
  78 int acpi_save_state_mem(void)
  79 {
  80         init_low_mapping();
  81
  82         memcpy((void *)acpi_wakeup_address, &wakeup_start,
  83                &wakeup_end - &wakeup_start);
  84         acpi_copy_wakeup_routine(acpi_wakeup_address);
  85
  86         return 0;
  87 }
  88
  89 /*
  90  * acpi_restore_state
  91  */
  92 void acpi_restore_state_mem(void)
  93 {
  94         set_pgd(pgd_offset(current->mm, 0UL), low_ptr);
  95         flush_tlb_all();
  96 }
  97
  98 /**
  99  * acpi_reserve_bootmem - do _very_ early ACPI initialisation
 100  *
 101  * We allocate a page in low memory for the wakeup
 102  * routine for when we come back from a sleep state. The
 103  * runtime allocator allows specification of <16M pages, but not
 104  * <1M pages.
 105  */
 106 void __init acpi_reserve_bootmem(void)
 107 {
 108         acpi_wakeup_address = (unsigned long)alloc_bootmem_low(PAGE_SIZE);
 109         if ((&wakeup_end - &wakeup_start) > PAGE_SIZE)
 110                 printk(KERN_CRIT
 111                        "ACPI: Wakeup code way too big, will crash on attempt to suspend\n");
 112 }
 113
 114 static int __init acpi_sleep_setup(char *str)
 115 {
 116         while ((str != NULL) && (*str != '\0')) {
 117                 if (strncmp(str, "s3_bios", 7) == 0)
 118                         acpi_video_flags = 1;
 119                 if (strncmp(str, "s3_mode", 7) == 0)
 120                         acpi_video_flags |= 2;
 121                 str = strchr(str, ',');
 122                 if (str != NULL)
 123                         str += strspn(str, ", \t");
 124         }
 125         return 1;
 126 }
 127
 128 __setup("acpi_sleep=", acpi_sleep_setup);
 129
 130 #endif                          /*CONFIG_ACPI_SLEEP */
 131
 132 void acpi_pci_link_exit(void)
 133 {
 134 }