2 * Hibernation support for x86-64
4 * Distribute under GPLv2
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>
11 #include <linux/gfp.h>
12 #include <linux/smp.h>
13 #include <linux/suspend.h>
14 #include <linux/scatterlist.h>
15 #include <linux/kdebug.h>
17 #include <crypto/hash.h>
20 #include <asm/proto.h>
22 #include <asm/pgtable.h>
24 #include <asm/sections.h>
25 #include <asm/suspend.h>
26 #include <asm/tlbflush.h>
28 /* Defined in hibernate_asm_64.S */
29 extern asmlinkage __visible int restore_image(void);
32 * Address to jump to in the last phase of restore in order to get to the image
33 * kernel's text (this value is passed in the image header).
35 unsigned long restore_jump_address __visible;
36 unsigned long jump_address_phys;
39 * Value of the cr3 register from before the hibernation (this value is passed
40 * in the image header).
42 unsigned long restore_cr3 __visible;
44 unsigned long temp_level4_pgt __visible;
46 unsigned long relocated_restore_code __visible;
48 static int set_up_temporary_text_mapping(pgd_t *pgd)
54 * The new mapping only has to cover the page containing the image
55 * kernel's entry point (jump_address_phys), because the switch over to
56 * it is carried out by relocated code running from a page allocated
57 * specifically for this purpose and covered by the identity mapping, so
58 * the temporary kernel text mapping is only needed for the final jump.
59 * Moreover, in that mapping the virtual address of the image kernel's
60 * entry point must be the same as its virtual address in the image
61 * kernel (restore_jump_address), so the image kernel's
62 * restore_registers() code doesn't find itself in a different area of
63 * the virtual address space after switching over to the original page
64 * tables used by the image kernel.
66 pud = (pud_t *)get_safe_page(GFP_ATOMIC);
70 pmd = (pmd_t *)get_safe_page(GFP_ATOMIC);
74 set_pmd(pmd + pmd_index(restore_jump_address),
75 __pmd((jump_address_phys & PMD_MASK) | __PAGE_KERNEL_LARGE_EXEC));
76 set_pud(pud + pud_index(restore_jump_address),
77 __pud(__pa(pmd) | _KERNPG_TABLE));
78 set_pgd(pgd + pgd_index(restore_jump_address),
79 __pgd(__pa(pud) | _KERNPG_TABLE));
84 static void *alloc_pgt_page(void *context)
86 return (void *)get_safe_page(GFP_ATOMIC);
89 static int set_up_temporary_mappings(void)
91 struct x86_mapping_info info = {
92 .alloc_pgt_page = alloc_pgt_page,
93 .pmd_flag = __PAGE_KERNEL_LARGE_EXEC,
94 .offset = __PAGE_OFFSET,
96 unsigned long mstart, mend;
101 pgd = (pgd_t *)get_safe_page(GFP_ATOMIC);
105 /* Prepare a temporary mapping for the kernel text */
106 result = set_up_temporary_text_mapping(pgd);
110 /* Set up the direct mapping from scratch */
111 for (i = 0; i < nr_pfn_mapped; i++) {
112 mstart = pfn_mapped[i].start << PAGE_SHIFT;
113 mend = pfn_mapped[i].end << PAGE_SHIFT;
115 result = kernel_ident_mapping_init(&info, pgd, mstart, mend);
120 temp_level4_pgt = __pa(pgd);
124 static int relocate_restore_code(void)
129 relocated_restore_code = get_safe_page(GFP_ATOMIC);
130 if (!relocated_restore_code)
133 memcpy((void *)relocated_restore_code, &core_restore_code, PAGE_SIZE);
135 /* Make the page containing the relocated code executable */
136 pgd = (pgd_t *)__va(read_cr3()) + pgd_index(relocated_restore_code);
137 pud = pud_offset(pgd, relocated_restore_code);
138 if (pud_large(*pud)) {
139 set_pud(pud, __pud(pud_val(*pud) & ~_PAGE_NX));
141 pmd_t *pmd = pmd_offset(pud, relocated_restore_code);
143 if (pmd_large(*pmd)) {
144 set_pmd(pmd, __pmd(pmd_val(*pmd) & ~_PAGE_NX));
146 pte_t *pte = pte_offset_kernel(pmd, relocated_restore_code);
148 set_pte(pte, __pte(pte_val(*pte) & ~_PAGE_NX));
156 int swsusp_arch_resume(void)
160 /* We have got enough memory and from now on we cannot recover */
161 error = set_up_temporary_mappings();
165 error = relocate_restore_code();
174 * pfn_is_nosave - check if given pfn is in the 'nosave' section
177 int pfn_is_nosave(unsigned long pfn)
179 unsigned long nosave_begin_pfn = __pa_symbol(&__nosave_begin) >> PAGE_SHIFT;
180 unsigned long nosave_end_pfn = PAGE_ALIGN(__pa_symbol(&__nosave_end)) >> PAGE_SHIFT;
181 return (pfn >= nosave_begin_pfn) && (pfn < nosave_end_pfn);
184 #define MD5_DIGEST_SIZE 16
186 struct restore_data_record {
187 unsigned long jump_address;
188 unsigned long jump_address_phys;
191 u8 e820_digest[MD5_DIGEST_SIZE];
194 #define RESTORE_MAGIC 0x23456789ABCDEF01UL
196 #if IS_BUILTIN(CONFIG_CRYPTO_MD5)
198 * get_e820_md5 - calculate md5 according to given e820 map
200 * @map: the e820 map to be calculated
201 * @buf: the md5 result to be stored to
203 static int get_e820_md5(struct e820map *map, void *buf)
205 struct scatterlist sg;
206 struct crypto_ahash *tfm;
210 tfm = crypto_alloc_ahash("md5", 0, CRYPTO_ALG_ASYNC);
215 AHASH_REQUEST_ON_STACK(req, tfm);
216 size = offsetof(struct e820map, map)
217 + sizeof(struct e820entry) * map->nr_map;
218 ahash_request_set_tfm(req, tfm);
219 sg_init_one(&sg, (u8 *)map, size);
220 ahash_request_set_callback(req, 0, NULL, NULL);
221 ahash_request_set_crypt(req, &sg, buf, size);
223 if (crypto_ahash_digest(req))
225 ahash_request_zero(req);
227 crypto_free_ahash(tfm);
232 static void hibernation_e820_save(void *buf)
234 get_e820_md5(e820_saved, buf);
237 static bool hibernation_e820_mismatch(void *buf)
240 u8 result[MD5_DIGEST_SIZE];
242 memset(result, 0, MD5_DIGEST_SIZE);
243 /* If there is no digest in suspend kernel, let it go. */
244 if (!memcmp(result, buf, MD5_DIGEST_SIZE))
247 ret = get_e820_md5(e820_saved, result);
251 return memcmp(result, buf, MD5_DIGEST_SIZE) ? true : false;
254 static void hibernation_e820_save(void *buf)
258 static bool hibernation_e820_mismatch(void *buf)
260 /* If md5 is not builtin for restore kernel, let it go. */
266 * arch_hibernation_header_save - populate the architecture specific part
267 * of a hibernation image header
268 * @addr: address to save the data at
270 int arch_hibernation_header_save(void *addr, unsigned int max_size)
272 struct restore_data_record *rdr = addr;
274 if (max_size < sizeof(struct restore_data_record))
276 rdr->jump_address = (unsigned long)&restore_registers;
277 rdr->jump_address_phys = __pa_symbol(&restore_registers);
278 rdr->cr3 = restore_cr3;
279 rdr->magic = RESTORE_MAGIC;
281 hibernation_e820_save(rdr->e820_digest);
287 * arch_hibernation_header_restore - read the architecture specific data
288 * from the hibernation image header
289 * @addr: address to read the data from
291 int arch_hibernation_header_restore(void *addr)
293 struct restore_data_record *rdr = addr;
295 restore_jump_address = rdr->jump_address;
296 jump_address_phys = rdr->jump_address_phys;
297 restore_cr3 = rdr->cr3;
299 if (rdr->magic != RESTORE_MAGIC) {
300 pr_crit("Unrecognized hibernate image header format!\n");
304 if (hibernation_e820_mismatch(rdr->e820_digest)) {
305 pr_crit("Hibernate inconsistent memory map detected!\n");