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 } 221