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 #include <asm/suspend.h>
  18
  19 /* References to section boundaries */
  20 extern const void __nosave_begin, __nosave_end;
  21
  22 /* Defined in hibernate_asm_64.S */
  23 extern 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  */
  29 unsigned 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  */
  35 unsigned long restore_cr3;
  36
  37 pgd_t *temp_level4_pgt;
  38
  39 void *relocated_restore_code;
  40
  41 static 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
  72 static 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
 104 int 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
 126 int 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
 133 struct 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  */
 146 int 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  */
 163 int 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 }