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@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 */
  19 extern const void __nosave_begin, __nosave_end;
  20
  21 /* Defined in hibernate_asm_64.S */
  22 extern 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  */
  28 unsigned 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  */
  34 unsigned long restore_cr3;
  35
  36 pgd_t *temp_level4_pgt;
  37
  38 void *relocated_restore_code;
  39
  40 static 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
  71 static 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
 103 int 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
 125 int 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
 132 struct 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  */
 145 int 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  */
 162 int 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 }