linux/arch/x86/power/hibernate_64.c
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   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
  18/* References to section boundaries */
  19extern const void __nosave_begin, __nosave_end;
  20
  21/* Defined in hibernate_asm_64.S */
  22extern int restore_image(void);
  23
  24/*
  25 * Address to jump to in the last phase of restore in order to get to the image
  26 * kernel's text (this value is passed in the image header).
  27 */
  28unsigned long restore_jump_address;
  29
  30/*
  31 * Value of the cr3 register from before the hibernation (this value is passed
  32 * in the image header).
  33 */
  34unsigned long restore_cr3;
  35
  36pgd_t *temp_level4_pgt;
  37
  38void *relocated_restore_code;
  39
  40static int res_phys_pud_init(pud_t *pud, unsigned long address, unsigned long end)
  41{
  42        long i, j;
  43
  44        i = pud_index(address);
  45        pud = pud + i;
  46        for (; i < PTRS_PER_PUD; pud++, i++) {
  47                unsigned long paddr;
  48                pmd_t *pmd;
  49
  50                paddr = address + i*PUD_SIZE;
  51                if (paddr >= end)
  52                        break;
  53
  54                pmd = (pmd_t *)get_safe_page(GFP_ATOMIC);
  55                if (!pmd)
  56                        return -ENOMEM;
  57                set_pud(pud, __pud(__pa(pmd) | _KERNPG_TABLE));
  58                for (j = 0; j < PTRS_PER_PMD; pmd++, j++, paddr += PMD_SIZE) {
  59                        unsigned long pe;
  60
  61                        if (paddr >= end)
  62                                break;
  63                        pe = __PAGE_KERNEL_LARGE_EXEC | paddr;
  64                        pe &= __supported_pte_mask;
  65                        set_pmd(pmd, __pmd(pe));
  66                }
  67        }
  68        return 0;
  69}
  70
  71static int set_up_temporary_mappings(void)
  72{
  73        unsigned long start, end, next;
  74        int error;
  75
  76        temp_level4_pgt = (pgd_t *)get_safe_page(GFP_ATOMIC);
  77        if (!temp_level4_pgt)
  78                return -ENOMEM;
  79
  80        /* It is safe to reuse the original kernel mapping */
  81        set_pgd(temp_level4_pgt + pgd_index(__START_KERNEL_map),
  82                init_level4_pgt[pgd_index(__START_KERNEL_map)]);
  83
  84        /* Set up the direct mapping from scratch */
  85        start = (unsigned long)pfn_to_kaddr(0);
  86        end = (unsigned long)pfn_to_kaddr(max_pfn);
  87
  88        for (; start < end; start = next) {
  89                pud_t *pud = (pud_t *)get_safe_page(GFP_ATOMIC);
  90                if (!pud)
  91                        return -ENOMEM;
  92                next = start + PGDIR_SIZE;
  93                if (next > end)
  94                        next = end;
  95                if ((error = res_phys_pud_init(pud, __pa(start), __pa(next))))
  96                        return error;
  97                set_pgd(temp_level4_pgt + pgd_index(start),
  98                        mk_kernel_pgd(__pa(pud)));
  99        }
 100        return 0;
 101}
 102
 103int swsusp_arch_resume(void)
 104{
 105        int error;
 106
 107        /* We have got enough memory and from now on we cannot recover */
 108        if ((error = set_up_temporary_mappings()))
 109                return error;
 110
 111        relocated_restore_code = (void *)get_safe_page(GFP_ATOMIC);
 112        if (!relocated_restore_code)
 113                return -ENOMEM;
 114        memcpy(relocated_restore_code, &core_restore_code,
 115               &restore_registers - &core_restore_code);
 116
 117        restore_image();
 118        return 0;
 119}
 120
 121/*
 122 *      pfn_is_nosave - check if given pfn is in the 'nosave' section
 123 */
 124
 125int pfn_is_nosave(unsigned long pfn)
 126{
 127        unsigned long nosave_begin_pfn = __pa_symbol(&__nosave_begin) >> PAGE_SHIFT;
 128        unsigned long nosave_end_pfn = PAGE_ALIGN(__pa_symbol(&__nosave_end)) >> PAGE_SHIFT;
 129        return (pfn >= nosave_begin_pfn) && (pfn < nosave_end_pfn);
 130}
 131
 132struct restore_data_record {
 133        unsigned long jump_address;
 134        unsigned long cr3;
 135        unsigned long magic;
 136};
 137
 138#define RESTORE_MAGIC   0x0123456789ABCDEFUL
 139
 140/**
 141 *      arch_hibernation_header_save - populate the architecture specific part
 142 *              of a hibernation image header
 143 *      @addr: address to save the data at
 144 */
 145int arch_hibernation_header_save(void *addr, unsigned int max_size)
 146{
 147        struct restore_data_record *rdr = addr;
 148
 149        if (max_size < sizeof(struct restore_data_record))
 150                return -EOVERFLOW;
 151        rdr->jump_address = restore_jump_address;
 152        rdr->cr3 = restore_cr3;
 153        rdr->magic = RESTORE_MAGIC;
 154        return 0;
 155}
 156
 157/**
 158 *      arch_hibernation_header_restore - read the architecture specific data
 159 *              from the hibernation image header
 160 *      @addr: address to read the data from
 161 */
 162int arch_hibernation_header_restore(void *addr)
 163{
 164        struct restore_data_record *rdr = addr;
 165
 166        restore_jump_address = rdr->jump_address;
 167        restore_cr3 = rdr->cr3;
 168        return (rdr->magic == RESTORE_MAGIC) ? 0 : -EINVAL;
 169}
 170