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
  15 #include <asm/init.h>
  16 #include <asm/proto.h>
  17 #include <asm/page.h>
  18 #include <asm/pgtable.h>
  19 #include <asm/mtrr.h>
  20 #include <asm/sections.h>
  21 #include <asm/suspend.h>
  22
  23 /* Defined in hibernate_asm_64.S */
  24 extern asmlinkage __visible 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 __visible;
  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 __visible;
  37
  38 pgd_t *temp_level4_pgt __visible;
  39
  40 void *relocated_restore_code __visible;
  41
  42 static void *alloc_pgt_page(void *context)
  43 {
  44         return (void *)get_safe_page(GFP_ATOMIC);
  45 }
  46
  47 static int set_up_temporary_mappings(void)
  48 {
  49         struct x86_mapping_info info = {
  50                 .alloc_pgt_page = alloc_pgt_page,
  51                 .pmd_flag       = __PAGE_KERNEL_LARGE_EXEC,
  52                 .kernel_mapping = true,
  53         };
  54         unsigned long mstart, mend;
  55         int result;
  56         int i;
  57
  58         temp_level4_pgt = (pgd_t *)get_safe_page(GFP_ATOMIC);
  59         if (!temp_level4_pgt)
  60                 return -ENOMEM;
  61
  62         /* It is safe to reuse the original kernel mapping */
  63         set_pgd(temp_level4_pgt + pgd_index(__START_KERNEL_map),
  64                 init_level4_pgt[pgd_index(__START_KERNEL_map)]);
  65
  66         /* Set up the direct mapping from scratch */
  67         for (i = 0; i < nr_pfn_mapped; i++) {
  68                 mstart = pfn_mapped[i].start << PAGE_SHIFT;
  69                 mend   = pfn_mapped[i].end << PAGE_SHIFT;
  70
  71                 result = kernel_ident_mapping_init(&info, temp_level4_pgt,
  72                                                    mstart, mend);
  73
  74                 if (result)
  75                         return result;
  76         }
  77
  78         return 0;
  79 }
  80
  81 int swsusp_arch_resume(void)
  82 {
  83         int error;
  84
  85         /* We have got enough memory and from now on we cannot recover */
  86         if ((error = set_up_temporary_mappings()))
  87                 return error;
  88
  89         relocated_restore_code = (void *)get_safe_page(GFP_ATOMIC);
  90         if (!relocated_restore_code)
  91                 return -ENOMEM;
  92         memcpy(relocated_restore_code, &core_restore_code,
  93                &restore_registers - &core_restore_code);
  94
  95         restore_image();
  96         return 0;
  97 }
  98
  99 /*
 100  *      pfn_is_nosave - check if given pfn is in the 'nosave' section
 101  */
 102
 103 int pfn_is_nosave(unsigned long pfn)
 104 {
 105         unsigned long nosave_begin_pfn = __pa_symbol(&__nosave_begin) >> PAGE_SHIFT;
 106         unsigned long nosave_end_pfn = PAGE_ALIGN(__pa_symbol(&__nosave_end)) >> PAGE_SHIFT;
 107         return (pfn >= nosave_begin_pfn) && (pfn < nosave_end_pfn);
 108 }
 109
 110 struct restore_data_record {
 111         unsigned long jump_address;
 112         unsigned long cr3;
 113         unsigned long magic;
 114 };
 115
 116 #define RESTORE_MAGIC   0x0123456789ABCDEFUL
 117
 118 /**
 119  *      arch_hibernation_header_save - populate the architecture specific part
 120  *              of a hibernation image header
 121  *      @addr: address to save the data at
 122  */
 123 int arch_hibernation_header_save(void *addr, unsigned int max_size)
 124 {
 125         struct restore_data_record *rdr = addr;
 126
 127         if (max_size < sizeof(struct restore_data_record))
 128                 return -EOVERFLOW;
 129         rdr->jump_address = restore_jump_address;
 130         rdr->cr3 = restore_cr3;
 131         rdr->magic = RESTORE_MAGIC;
 132         return 0;
 133 }
 134
 135 /**
 136  *      arch_hibernation_header_restore - read the architecture specific data
 137  *              from the hibernation image header
 138  *      @addr: address to read the data from
 139  */
 140 int arch_hibernation_header_restore(void *addr)
 141 {
 142         struct restore_data_record *rdr = addr;
 143
 144         restore_jump_address = rdr->jump_address;
 145         restore_cr3 = rdr->cr3;
 146         return (rdr->magic == RESTORE_MAGIC) ? 0 : -EINVAL;
 147 }