LXR linux/arch/x86/power/hibernate

   1/*
   2 * Hibernation support for x86-64
   3 *
   4 * Distribute under GPLv2
   5 *
   6 * Copyright (c) 2007 Rafael J. Wysocki <rjw@sisk.pl>
   7 * Copyright (c) 2002 Pavel Machek <pavel@suse.cz>
   8 * Copyright (c) 2001 Patrick Mochel <mochel@osdl.org>
   9 */
  10
  11#include <linux/smp.h>
  12#include <linux/suspend.h>
  13#include <asm/proto.h>
  14#include <asm/page.h>
  15#include <asm/pgtable.h>
  16#include <asm/mtrr.h>
  17#include <asm/suspend.h>
  18
  19/* References to section boundaries */
  20extern const void __nosave_begin, __nosave_end;
  21
  22/* Defined in hibernate_asm_64.S */
  23extern int restore_image(void);
  24
  25/*
  26 * Address to jump to in the last phase of restore in order to get to the image
  27 * kernel's text (this value is passed in the image header).
  28 */
  29unsigned long restore_jump_address;
  30
  31/*
  32 * Value of the cr3 register from before the hibernation (this value is passed
  33 * in the image header).
  34 */
  35unsigned long restore_cr3;
  36
  37pgd_t *temp_level4_pgt;
  38
  39void *relocated_restore_code;
  40
  41static int res_phys_pud_init(pud_t *pud, unsigned long address, unsigned long end)
  42{
  43        long i, j;
  44
  45        i = pud_index(address);
  46        pud = pud + i;
  47        for (; i < PTRS_PER_PUD; pud++, i++) {
  48                unsigned long paddr;
  49                pmd_t *pmd;
  50
  51                paddr = address + i*PUD_SIZE;
  52                if (paddr >= end)
  53                        break;
  54
  55                pmd = (pmd_t *)get_safe_page(GFP_ATOMIC);
  56                if (!pmd)
  57                        return -ENOMEM;
  58                set_pud(pud, __pud(__pa(pmd) | _KERNPG_TABLE));
  59                for (j = 0; j < PTRS_PER_PMD; pmd++, j++, paddr += PMD_SIZE) {
  60                        unsigned long pe;
  61
  62                        if (paddr >= end)
  63                                break;
  64                        pe = __PAGE_KERNEL_LARGE_EXEC | paddr;
  65                        pe &= __supported_pte_mask;
  66                        set_pmd(pmd, __pmd(pe));
  67                }
  68        }
  69        return 0;
  70}
  71
  72static int set_up_temporary_mappings(void)
  73{
  74        unsigned long start, end, next;
  75        int error;
  76
  77        temp_level4_pgt = (pgd_t *)get_safe_page(GFP_ATOMIC);
  78        if (!temp_level4_pgt)
  79                return -ENOMEM;
  80
  81        /* It is safe to reuse the original kernel mapping */
  82        set_pgd(temp_level4_pgt + pgd_index(__START_KERNEL_map),
  83                init_level4_pgt[pgd_index(__START_KERNEL_map)]);
  84
  85        /* Set up the direct mapping from scratch */
  86        start = (unsigned long)pfn_to_kaddr(0);
  87        end = (unsigned long)pfn_to_kaddr(max_pfn);
  88
  89        for (; start < end; start = next) {
  90                pud_t *pud = (pud_t *)get_safe_page(GFP_ATOMIC);
  91                if (!pud)
  92                        return -ENOMEM;
  93                next = start + PGDIR_SIZE;
  94                if (next > end)
  95                        next = end;
  96                if ((error = res_phys_pud_init(pud, __pa(start), __pa(next))))
  97                        return error;
  98                set_pgd(temp_level4_pgt + pgd_index(start),
  99                        mk_kernel_pgd(__pa(pud)));
 100        }
 101        return 0;
 102}
 103
 104int swsusp_arch_resume(void)
 105{
 106        int error;
 107
 108        /* We have got enough memory and from now on we cannot recover */
 109        if ((error = set_up_temporary_mappings()))
 110                return error;
 111
 112        relocated_restore_code = (void *)get_safe_page(GFP_ATOMIC);
 113        if (!relocated_restore_code)
 114                return -ENOMEM;
 115        memcpy(relocated_restore_code, &core_restore_code,
 116               &restore_registers - &core_restore_code);
 117
 118        restore_image();
 119        return 0;
 120}
 121
 122/*
 123 *      pfn_is_nosave - check if given pfn is in the 'nosave' section
 124 */
 125
 126int pfn_is_nosave(unsigned long pfn)
 127{
 128        unsigned long nosave_begin_pfn = __pa_symbol(&__nosave_begin) >> PAGE_SHIFT;
 129        unsigned long nosave_end_pfn = PAGE_ALIGN(__pa_symbol(&__nosave_end)) >> PAGE_SHIFT;
 130        return (pfn >= nosave_begin_pfn) && (pfn < nosave_end_pfn);
 131}
 132
 133struct restore_data_record {
 134        unsigned long jump_address;
 135        unsigned long cr3;
 136        unsigned long magic;
 137};
 138
 139#define RESTORE_MAGIC   0x0123456789ABCDEFUL
 140
 141/**
 142 *      arch_hibernation_header_save - populate the architecture specific part
 143 *              of a hibernation image header
 144 *      @addr: address to save the data at
 145 */
 146int arch_hibernation_header_save(void *addr, unsigned int max_size)
 147{
 148        struct restore_data_record *rdr = addr;
 149
 150        if (max_size < sizeof(struct restore_data_record))
 151                return -EOVERFLOW;
 152        rdr->jump_address = restore_jump_address;
 153        rdr->cr3 = restore_cr3;
 154        rdr->magic = RESTORE_MAGIC;
 155        return 0;
 156}
 157
 158/**
 159 *      arch_hibernation_header_restore - read the architecture specific data
 160 *              from the hibernation image header
 161 *      @addr: address to read the data from
 162 */
 163int arch_hibernation_header_restore(void *addr)
 164{
 165        struct restore_data_record *rdr = addr;
 166
 167        restore_jump_address = rdr->jump_address;
 168        restore_cr3 = rdr->cr3;
 169        return (rdr->magic == RESTORE_MAGIC) ? 0 : -EINVAL;
 170}
 171