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@ucw.cz>
   8 * Copyright (c) 2001 Patrick Mochel <mochel@osdl.org>
   9 */
  10
  11#include <linux/gfp.h>
  12#include <linux/smp.h>
  13#include <linux/suspend.h>
  14#include <asm/proto.h>
  15#include <asm/page.h>
  16#include <asm/pgtable.h>
  17#include <asm/mtrr.h>
  18#include <asm/suspend.h>
  19
  20/* References to section boundaries */
  21extern const void __nosave_begin, __nosave_end;
  22
  23/* Defined in hibernate_asm_64.S */
  24extern int restore_image(void);
  25
  26/*
  27 * Address to jump to in the last phase of restore in order to get to the image
  28 * kernel's text (this value is passed in the image header).
  29 */
  30unsigned long restore_jump_address;
  31
  32/*
  33 * Value of the cr3 register from before the hibernation (this value is passed
  34 * in the image header).
  35 */
  36unsigned long restore_cr3;
  37
  38pgd_t *temp_level4_pgt;
  39
  40void *relocated_restore_code;
  41
  42static int res_phys_pud_init(pud_t *pud, unsigned long address, unsigned long end)
  43{
  44        long i, j;
  45
  46        i = pud_index(address);
  47        pud = pud + i;
  48        for (; i < PTRS_PER_PUD; pud++, i++) {
  49                unsigned long paddr;
  50                pmd_t *pmd;
  51
  52                paddr = address + i*PUD_SIZE;
  53                if (paddr >= end)
  54                        break;
  55
  56                pmd = (pmd_t *)get_safe_page(GFP_ATOMIC);
  57                if (!pmd)
  58                        return -ENOMEM;
  59                set_pud(pud, __pud(__pa(pmd) | _KERNPG_TABLE));
  60                for (j = 0; j < PTRS_PER_PMD; pmd++, j++, paddr += PMD_SIZE) {
  61                        unsigned long pe;
  62
  63                        if (paddr >= end)
  64                                break;
  65                        pe = __PAGE_KERNEL_LARGE_EXEC | paddr;
  66                        pe &= __supported_pte_mask;
  67                        set_pmd(pmd, __pmd(pe));
  68                }
  69        }
  70        return 0;
  71}
  72
  73static int set_up_temporary_mappings(void)
  74{
  75        unsigned long start, end, next;
  76        int error;
  77
  78        temp_level4_pgt = (pgd_t *)get_safe_page(GFP_ATOMIC);
  79        if (!temp_level4_pgt)
  80                return -ENOMEM;
  81
  82        /* It is safe to reuse the original kernel mapping */
  83        set_pgd(temp_level4_pgt + pgd_index(__START_KERNEL_map),
  84                init_level4_pgt[pgd_index(__START_KERNEL_map)]);
  85
  86        /* Set up the direct mapping from scratch */
  87        start = (unsigned long)pfn_to_kaddr(0);
  88        end = (unsigned long)pfn_to_kaddr(max_pfn);
  89
  90        for (; start < end; start = next) {
  91                pud_t *pud = (pud_t *)get_safe_page(GFP_ATOMIC);
  92                if (!pud)
  93                        return -ENOMEM;
  94                next = start + PGDIR_SIZE;
  95                if (next > end)
  96                        next = end;
  97                if ((error = res_phys_pud_init(pud, __pa(start), __pa(next))))
  98                        return error;
  99                set_pgd(temp_level4_pgt + pgd_index(start),
 100                        mk_kernel_pgd(__pa(pud)));
 101        }
 102        return 0;
 103}
 104
 105int swsusp_arch_resume(void)
 106{
 107        int error;
 108
 109        /* We have got enough memory and from now on we cannot recover */
 110        if ((error = set_up_temporary_mappings()))
 111                return error;
 112
 113        relocated_restore_code = (void *)get_safe_page(GFP_ATOMIC);
 114        if (!relocated_restore_code)
 115                return -ENOMEM;
 116        memcpy(relocated_restore_code, &core_restore_code,
 117               &restore_registers - &core_restore_code);
 118
 119        restore_image();
 120        return 0;
 121}
 122
 123/*
 124 *      pfn_is_nosave - check if given pfn is in the 'nosave' section
 125 */
 126
 127int pfn_is_nosave(unsigned long pfn)
 128{
 129        unsigned long nosave_begin_pfn = __pa_symbol(&__nosave_begin) >> PAGE_SHIFT;
 130        unsigned long nosave_end_pfn = PAGE_ALIGN(__pa_symbol(&__nosave_end)) >> PAGE_SHIFT;
 131        return (pfn >= nosave_begin_pfn) && (pfn < nosave_end_pfn);
 132}
 133
 134struct restore_data_record {
 135        unsigned long jump_address;
 136        unsigned long cr3;
 137        unsigned long magic;
 138};
 139
 140#define RESTORE_MAGIC   0x0123456789ABCDEFUL
 141
 142/**
 143 *      arch_hibernation_header_save - populate the architecture specific part
 144 *              of a hibernation image header
 145 *      @addr: address to save the data at
 146 */
 147int arch_hibernation_header_save(void *addr, unsigned int max_size)
 148{
 149        struct restore_data_record *rdr = addr;
 150
 151        if (max_size < sizeof(struct restore_data_record))
 152                return -EOVERFLOW;
 153        rdr->jump_address = restore_jump_address;
 154        rdr->cr3 = restore_cr3;
 155        rdr->magic = RESTORE_MAGIC;
 156        return 0;
 157}
 158
 159/**
 160 *      arch_hibernation_header_restore - read the architecture specific data
 161 *              from the hibernation image header
 162 *      @addr: address to read the data from
 163 */
 164int arch_hibernation_header_restore(void *addr)
 165{
 166        struct restore_data_record *rdr = addr;
 167
 168        restore_jump_address = rdr->jump_address;
 169        restore_cr3 = rdr->cr3;
 170        return (rdr->magic == RESTORE_MAGIC) ? 0 : -EINVAL;
 171}
 172