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 #include <asm/tlbflush.h>
  23
  24 /* Defined in hibernate_asm_64.S */
  25 extern asmlinkage __visible int restore_image(void);
  26
  27 /*
  28  * Address to jump to in the last phase of restore in order to get to the image
  29  * kernel's text (this value is passed in the image header).
  30  */
  31 unsigned long restore_jump_address __visible;
  32 unsigned long jump_address_phys;
  33
  34 /*
  35  * Value of the cr3 register from before the hibernation (this value is passed
  36  * in the image header).
  37  */
  38 unsigned long restore_cr3 __visible;
  39
  40 pgd_t *temp_level4_pgt __visible;
  41
  42 unsigned long relocated_restore_code __visible;
  43
  44 static int set_up_temporary_text_mapping(void)
  45 {
  46         pmd_t *pmd;
  47         pud_t *pud;
  48
  49         /*
  50          * The new mapping only has to cover the page containing the image
  51          * kernel's entry point (jump_address_phys), because the switch over to
  52          * it is carried out by relocated code running from a page allocated
  53          * specifically for this purpose and covered by the identity mapping, so
  54          * the temporary kernel text mapping is only needed for the final jump.
  55          * Moreover, in that mapping the virtual address of the image kernel's
  56          * entry point must be the same as its virtual address in the image
  57          * kernel (restore_jump_address), so the image kernel's
  58          * restore_registers() code doesn't find itself in a different area of
  59          * the virtual address space after switching over to the original page
  60          * tables used by the image kernel.
  61          */
  62         pud = (pud_t *)get_safe_page(GFP_ATOMIC);
  63         if (!pud)
  64                 return -ENOMEM;
  65
  66         pmd = (pmd_t *)get_safe_page(GFP_ATOMIC);
  67         if (!pmd)
  68                 return -ENOMEM;
  69
  70         set_pmd(pmd + pmd_index(restore_jump_address),
  71                 __pmd((jump_address_phys & PMD_MASK) | __PAGE_KERNEL_LARGE_EXEC));
  72         set_pud(pud + pud_index(restore_jump_address),
  73                 __pud(__pa(pmd) | _KERNPG_TABLE));
  74         set_pgd(temp_level4_pgt + pgd_index(restore_jump_address),
  75                 __pgd(__pa(pud) | _KERNPG_TABLE));
  76
  77         return 0;
  78 }
  79
  80 static void *alloc_pgt_page(void *context)
  81 {
  82         return (void *)get_safe_page(GFP_ATOMIC);
  83 }
  84
  85 static int set_up_temporary_mappings(void)
  86 {
  87         struct x86_mapping_info info = {
  88                 .alloc_pgt_page = alloc_pgt_page,
  89                 .pmd_flag       = __PAGE_KERNEL_LARGE_EXEC,
  90                 .kernel_mapping = true,
  91         };
  92         unsigned long mstart, mend;
  93         int result;
  94         int i;
  95
  96         temp_level4_pgt = (pgd_t *)get_safe_page(GFP_ATOMIC);
  97         if (!temp_level4_pgt)
  98                 return -ENOMEM;
  99
 100         /* Prepare a temporary mapping for the kernel text */
 101         result = set_up_temporary_text_mapping();
 102         if (result)
 103                 return result;
 104
 105         /* Set up the direct mapping from scratch */
 106         for (i = 0; i < nr_pfn_mapped; i++) {
 107                 mstart = pfn_mapped[i].start << PAGE_SHIFT;
 108                 mend   = pfn_mapped[i].end << PAGE_SHIFT;
 109
 110                 result = kernel_ident_mapping_init(&info, temp_level4_pgt,
 111                                                    mstart, mend);
 112
 113                 if (result)
 114                         return result;
 115         }
 116
 117         return 0;
 118 }
 119
 120 static int relocate_restore_code(void)
 121 {
 122         pgd_t *pgd;
 123         pud_t *pud;
 124
 125         relocated_restore_code = get_safe_page(GFP_ATOMIC);
 126         if (!relocated_restore_code)
 127                 return -ENOMEM;
 128
 129         memcpy((void *)relocated_restore_code, &core_restore_code, PAGE_SIZE);
 130
 131         /* Make the page containing the relocated code executable */
 132         pgd = (pgd_t *)__va(read_cr3()) + pgd_index(relocated_restore_code);
 133         pud = pud_offset(pgd, relocated_restore_code);
 134         if (pud_large(*pud)) {
 135                 set_pud(pud, __pud(pud_val(*pud) & ~_PAGE_NX));
 136         } else {
 137                 pmd_t *pmd = pmd_offset(pud, relocated_restore_code);
 138
 139                 if (pmd_large(*pmd)) {
 140                         set_pmd(pmd, __pmd(pmd_val(*pmd) & ~_PAGE_NX));
 141                 } else {
 142                         pte_t *pte = pte_offset_kernel(pmd, relocated_restore_code);
 143
 144                         set_pte(pte, __pte(pte_val(*pte) & ~_PAGE_NX));
 145                 }
 146         }
 147         __flush_tlb_all();
 148
 149         return 0;
 150 }
 151
 152 int swsusp_arch_resume(void)
 153 {
 154         int error;
 155
 156         /* We have got enough memory and from now on we cannot recover */
 157         error = set_up_temporary_mappings();
 158         if (error)
 159                 return error;
 160
 161         error = relocate_restore_code();
 162         if (error)
 163                 return error;
 164
 165         restore_image();
 166         return 0;
 167 }
 168
 169 /*
 170  *      pfn_is_nosave - check if given pfn is in the 'nosave' section
 171  */
 172
 173 int pfn_is_nosave(unsigned long pfn)
 174 {
 175         unsigned long nosave_begin_pfn = __pa_symbol(&__nosave_begin) >> PAGE_SHIFT;
 176         unsigned long nosave_end_pfn = PAGE_ALIGN(__pa_symbol(&__nosave_end)) >> PAGE_SHIFT;
 177         return (pfn >= nosave_begin_pfn) && (pfn < nosave_end_pfn);
 178 }
 179
 180 struct restore_data_record {
 181         unsigned long jump_address;
 182         unsigned long jump_address_phys;
 183         unsigned long cr3;
 184         unsigned long magic;
 185 };
 186
 187 #define RESTORE_MAGIC   0x123456789ABCDEF0UL
 188
 189 /**
 190  *      arch_hibernation_header_save - populate the architecture specific part
 191  *              of a hibernation image header
 192  *      @addr: address to save the data at
 193  */
 194 int arch_hibernation_header_save(void *addr, unsigned int max_size)
 195 {
 196         struct restore_data_record *rdr = addr;
 197
 198         if (max_size < sizeof(struct restore_data_record))
 199                 return -EOVERFLOW;
 200         rdr->jump_address = (unsigned long)&restore_registers;
 201         rdr->jump_address_phys = __pa_symbol(&restore_registers);
 202         rdr->cr3 = restore_cr3;
 203         rdr->magic = RESTORE_MAGIC;
 204         return 0;
 205 }
 206
 207 /**
 208  *      arch_hibernation_header_restore - read the architecture specific data
 209  *              from the hibernation image header
 210  *      @addr: address to read the data from
 211  */
 212 int arch_hibernation_header_restore(void *addr)
 213 {
 214         struct restore_data_record *rdr = addr;
 215
 216         restore_jump_address = rdr->jump_address;
 217         jump_address_phys = rdr->jump_address_phys;
 218         restore_cr3 = rdr->cr3;
 219         return (rdr->magic == RESTORE_MAGIC) ? 0 : -EINVAL;
 220 }