arch/x86/power/hibernate_64.c

   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 */
  21 extern const void __nosave_begin, __nosave_end;
  22
  23 /* Defined in hibernate_asm_64.S */
  24 extern 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  */
  30 unsigned 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  */
  36 unsigned long restore_cr3;
  37
  38 pgd_t *temp_level4_pgt;
  39
  40 void *relocated_restore_code;
  41
  42 static 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
  73 static 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
 105 int 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
 127 int 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
 134 struct 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  */
 147 int 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  */
 164 int 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 }