| 1 | /* |
| 2 | * linux/kernel/power/snapshot.c |
| 3 | * |
| 4 | * This file provide system snapshot/restore functionality. |
| 5 | * |
| 6 | * Copyright (C) 1998-2005 Pavel Machek <pavel@suse.cz> |
| 7 | * |
| 8 | * This file is released under the GPLv2, and is based on swsusp.c. |
| 9 | * |
| 10 | */ |
| 11 | |
| 12 | |
| 13 | #include <linux/module.h> |
| 14 | #include <linux/mm.h> |
| 15 | #include <linux/suspend.h> |
| 16 | #include <linux/smp_lock.h> |
| 17 | #include <linux/delay.h> |
| 18 | #include <linux/bitops.h> |
| 19 | #include <linux/spinlock.h> |
| 20 | #include <linux/kernel.h> |
| 21 | #include <linux/pm.h> |
| 22 | #include <linux/device.h> |
| 23 | #include <linux/bootmem.h> |
| 24 | #include <linux/syscalls.h> |
| 25 | #include <linux/console.h> |
| 26 | #include <linux/highmem.h> |
| 27 | |
| 28 | #include <asm/uaccess.h> |
| 29 | #include <asm/mmu_context.h> |
| 30 | #include <asm/pgtable.h> |
| 31 | #include <asm/tlbflush.h> |
| 32 | #include <asm/io.h> |
| 33 | |
| 34 | #include "power.h" |
| 35 | |
| 36 | struct pbe *pagedir_nosave; |
| 37 | unsigned int nr_copy_pages; |
| 38 | |
| 39 | #ifdef CONFIG_HIGHMEM |
| 40 | unsigned int count_highmem_pages(void) |
| 41 | { |
| 42 | struct zone *zone; |
| 43 | unsigned long zone_pfn; |
| 44 | unsigned int n = 0; |
| 45 | |
| 46 | for_each_zone (zone) |
| 47 | if (is_highmem(zone)) { |
| 48 | mark_free_pages(zone); |
| 49 | for (zone_pfn = 0; zone_pfn < zone->spanned_pages; zone_pfn++) { |
| 50 | struct page *page; |
| 51 | unsigned long pfn = zone_pfn + zone->zone_start_pfn; |
| 52 | if (!pfn_valid(pfn)) |
| 53 | continue; |
| 54 | page = pfn_to_page(pfn); |
| 55 | if (PageReserved(page)) |
| 56 | continue; |
| 57 | if (PageNosaveFree(page)) |
| 58 | continue; |
| 59 | n++; |
| 60 | } |
| 61 | } |
| 62 | return n; |
| 63 | } |
| 64 | |
| 65 | struct highmem_page { |
| 66 | char *data; |
| 67 | struct page *page; |
| 68 | struct highmem_page *next; |
| 69 | }; |
| 70 | |
| 71 | static struct highmem_page *highmem_copy; |
| 72 | |
| 73 | static int save_highmem_zone(struct zone *zone) |
| 74 | { |
| 75 | unsigned long zone_pfn; |
| 76 | mark_free_pages(zone); |
| 77 | for (zone_pfn = 0; zone_pfn < zone->spanned_pages; ++zone_pfn) { |
| 78 | struct page *page; |
| 79 | struct highmem_page *save; |
| 80 | void *kaddr; |
| 81 | unsigned long pfn = zone_pfn + zone->zone_start_pfn; |
| 82 | |
| 83 | if (!(pfn%1000)) |
| 84 | printk("."); |
| 85 | if (!pfn_valid(pfn)) |
| 86 | continue; |
| 87 | page = pfn_to_page(pfn); |
| 88 | /* |
| 89 | * This condition results from rvmalloc() sans vmalloc_32() |
| 90 | * and architectural memory reservations. This should be |
| 91 | * corrected eventually when the cases giving rise to this |
| 92 | * are better understood. |
| 93 | */ |
| 94 | if (PageReserved(page)) { |
| 95 | printk("highmem reserved page?!\n"); |
| 96 | continue; |
| 97 | } |
| 98 | BUG_ON(PageNosave(page)); |
| 99 | if (PageNosaveFree(page)) |
| 100 | continue; |
| 101 | save = kmalloc(sizeof(struct highmem_page), GFP_ATOMIC); |
| 102 | if (!save) |
| 103 | return -ENOMEM; |
| 104 | save->next = highmem_copy; |
| 105 | save->page = page; |
| 106 | save->data = (void *) get_zeroed_page(GFP_ATOMIC); |
| 107 | if (!save->data) { |
| 108 | kfree(save); |
| 109 | return -ENOMEM; |
| 110 | } |
| 111 | kaddr = kmap_atomic(page, KM_USER0); |
| 112 | memcpy(save->data, kaddr, PAGE_SIZE); |
| 113 | kunmap_atomic(kaddr, KM_USER0); |
| 114 | highmem_copy = save; |
| 115 | } |
| 116 | return 0; |
| 117 | } |
| 118 | |
| 119 | int save_highmem(void) |
| 120 | { |
| 121 | struct zone *zone; |
| 122 | int res = 0; |
| 123 | |
| 124 | pr_debug("swsusp: Saving Highmem\n"); |
| 125 | for_each_zone (zone) { |
| 126 | if (is_highmem(zone)) |
| 127 | res = save_highmem_zone(zone); |
| 128 | if (res) |
| 129 | return res; |
| 130 | } |
| 131 | return 0; |
| 132 | } |
| 133 | |
| 134 | int restore_highmem(void) |
| 135 | { |
| 136 | printk("swsusp: Restoring Highmem\n"); |
| 137 | while (highmem_copy) { |
| 138 | struct highmem_page *save = highmem_copy; |
| 139 | void *kaddr; |
| 140 | highmem_copy = save->next; |
| 141 | |
| 142 | kaddr = kmap_atomic(save->page, KM_USER0); |
| 143 | memcpy(kaddr, save->data, PAGE_SIZE); |
| 144 | kunmap_atomic(kaddr, KM_USER0); |
| 145 | free_page((long) save->data); |
| 146 | kfree(save); |
| 147 | } |
| 148 | return 0; |
| 149 | } |
| 150 | #endif |
| 151 | |
| 152 | static int pfn_is_nosave(unsigned long pfn) |
| 153 | { |
| 154 | unsigned long nosave_begin_pfn = __pa(&__nosave_begin) >> PAGE_SHIFT; |
| 155 | unsigned long nosave_end_pfn = PAGE_ALIGN(__pa(&__nosave_end)) >> PAGE_SHIFT; |
| 156 | return (pfn >= nosave_begin_pfn) && (pfn < nosave_end_pfn); |
| 157 | } |
| 158 | |
| 159 | /** |
| 160 | * saveable - Determine whether a page should be cloned or not. |
| 161 | * @pfn: The page |
| 162 | * |
| 163 | * We save a page if it's Reserved, and not in the range of pages |
| 164 | * statically defined as 'unsaveable', or if it isn't reserved, and |
| 165 | * isn't part of a free chunk of pages. |
| 166 | */ |
| 167 | |
| 168 | static int saveable(struct zone *zone, unsigned long *zone_pfn) |
| 169 | { |
| 170 | unsigned long pfn = *zone_pfn + zone->zone_start_pfn; |
| 171 | struct page *page; |
| 172 | |
| 173 | if (!pfn_valid(pfn)) |
| 174 | return 0; |
| 175 | |
| 176 | page = pfn_to_page(pfn); |
| 177 | BUG_ON(PageReserved(page) && PageNosave(page)); |
| 178 | if (PageNosave(page)) |
| 179 | return 0; |
| 180 | if (PageReserved(page) && pfn_is_nosave(pfn)) |
| 181 | return 0; |
| 182 | if (PageNosaveFree(page)) |
| 183 | return 0; |
| 184 | |
| 185 | return 1; |
| 186 | } |
| 187 | |
| 188 | unsigned int count_data_pages(void) |
| 189 | { |
| 190 | struct zone *zone; |
| 191 | unsigned long zone_pfn; |
| 192 | unsigned int n = 0; |
| 193 | |
| 194 | for_each_zone (zone) { |
| 195 | if (is_highmem(zone)) |
| 196 | continue; |
| 197 | mark_free_pages(zone); |
| 198 | for (zone_pfn = 0; zone_pfn < zone->spanned_pages; ++zone_pfn) |
| 199 | n += saveable(zone, &zone_pfn); |
| 200 | } |
| 201 | return n; |
| 202 | } |
| 203 | |
| 204 | static void copy_data_pages(struct pbe *pblist) |
| 205 | { |
| 206 | struct zone *zone; |
| 207 | unsigned long zone_pfn; |
| 208 | struct pbe *pbe, *p; |
| 209 | |
| 210 | pbe = pblist; |
| 211 | for_each_zone (zone) { |
| 212 | if (is_highmem(zone)) |
| 213 | continue; |
| 214 | mark_free_pages(zone); |
| 215 | /* This is necessary for swsusp_free() */ |
| 216 | for_each_pb_page (p, pblist) |
| 217 | SetPageNosaveFree(virt_to_page(p)); |
| 218 | for_each_pbe (p, pblist) |
| 219 | SetPageNosaveFree(virt_to_page(p->address)); |
| 220 | for (zone_pfn = 0; zone_pfn < zone->spanned_pages; ++zone_pfn) { |
| 221 | if (saveable(zone, &zone_pfn)) { |
| 222 | struct page *page; |
| 223 | page = pfn_to_page(zone_pfn + zone->zone_start_pfn); |
| 224 | BUG_ON(!pbe); |
| 225 | pbe->orig_address = (unsigned long)page_address(page); |
| 226 | /* copy_page is not usable for copying task structs. */ |
| 227 | memcpy((void *)pbe->address, (void *)pbe->orig_address, PAGE_SIZE); |
| 228 | pbe = pbe->next; |
| 229 | } |
| 230 | } |
| 231 | } |
| 232 | BUG_ON(pbe); |
| 233 | } |
| 234 | |
| 235 | |
| 236 | /** |
| 237 | * free_pagedir - free pages allocated with alloc_pagedir() |
| 238 | */ |
| 239 | |
| 240 | void free_pagedir(struct pbe *pblist) |
| 241 | { |
| 242 | struct pbe *pbe; |
| 243 | |
| 244 | while (pblist) { |
| 245 | pbe = (pblist + PB_PAGE_SKIP)->next; |
| 246 | ClearPageNosave(virt_to_page(pblist)); |
| 247 | ClearPageNosaveFree(virt_to_page(pblist)); |
| 248 | free_page((unsigned long)pblist); |
| 249 | pblist = pbe; |
| 250 | } |
| 251 | } |
| 252 | |
| 253 | /** |
| 254 | * fill_pb_page - Create a list of PBEs on a given memory page |
| 255 | */ |
| 256 | |
| 257 | static inline void fill_pb_page(struct pbe *pbpage) |
| 258 | { |
| 259 | struct pbe *p; |
| 260 | |
| 261 | p = pbpage; |
| 262 | pbpage += PB_PAGE_SKIP; |
| 263 | do |
| 264 | p->next = p + 1; |
| 265 | while (++p < pbpage); |
| 266 | } |
| 267 | |
| 268 | /** |
| 269 | * create_pbe_list - Create a list of PBEs on top of a given chain |
| 270 | * of memory pages allocated with alloc_pagedir() |
| 271 | */ |
| 272 | |
| 273 | static inline void create_pbe_list(struct pbe *pblist, unsigned int nr_pages) |
| 274 | { |
| 275 | struct pbe *pbpage, *p; |
| 276 | unsigned int num = PBES_PER_PAGE; |
| 277 | |
| 278 | for_each_pb_page (pbpage, pblist) { |
| 279 | if (num >= nr_pages) |
| 280 | break; |
| 281 | |
| 282 | fill_pb_page(pbpage); |
| 283 | num += PBES_PER_PAGE; |
| 284 | } |
| 285 | if (pbpage) { |
| 286 | for (num -= PBES_PER_PAGE - 1, p = pbpage; num < nr_pages; p++, num++) |
| 287 | p->next = p + 1; |
| 288 | p->next = NULL; |
| 289 | } |
| 290 | } |
| 291 | |
| 292 | /** |
| 293 | * On resume it is necessary to trace and eventually free the unsafe |
| 294 | * pages that have been allocated, because they are needed for I/O |
| 295 | * (on x86-64 we likely will "eat" these pages once again while |
| 296 | * creating the temporary page translation tables) |
| 297 | */ |
| 298 | |
| 299 | struct eaten_page { |
| 300 | struct eaten_page *next; |
| 301 | char padding[PAGE_SIZE - sizeof(void *)]; |
| 302 | }; |
| 303 | |
| 304 | static struct eaten_page *eaten_pages = NULL; |
| 305 | |
| 306 | void release_eaten_pages(void) |
| 307 | { |
| 308 | struct eaten_page *p, *q; |
| 309 | |
| 310 | p = eaten_pages; |
| 311 | while (p) { |
| 312 | q = p->next; |
| 313 | /* We don't want swsusp_free() to free this page again */ |
| 314 | ClearPageNosave(virt_to_page(p)); |
| 315 | free_page((unsigned long)p); |
| 316 | p = q; |
| 317 | } |
| 318 | eaten_pages = NULL; |
| 319 | } |
| 320 | |
| 321 | /** |
| 322 | * @safe_needed - on resume, for storing the PBE list and the image, |
| 323 | * we can only use memory pages that do not conflict with the pages |
| 324 | * which had been used before suspend. |
| 325 | * |
| 326 | * The unsafe pages are marked with the PG_nosave_free flag |
| 327 | * |
| 328 | * Allocated but unusable (ie eaten) memory pages should be marked |
| 329 | * so that swsusp_free() can release them |
| 330 | */ |
| 331 | |
| 332 | static inline void *alloc_image_page(gfp_t gfp_mask, int safe_needed) |
| 333 | { |
| 334 | void *res; |
| 335 | |
| 336 | if (safe_needed) |
| 337 | do { |
| 338 | res = (void *)get_zeroed_page(gfp_mask); |
| 339 | if (res && PageNosaveFree(virt_to_page(res))) { |
| 340 | /* This is for swsusp_free() */ |
| 341 | SetPageNosave(virt_to_page(res)); |
| 342 | ((struct eaten_page *)res)->next = eaten_pages; |
| 343 | eaten_pages = res; |
| 344 | } |
| 345 | } while (res && PageNosaveFree(virt_to_page(res))); |
| 346 | else |
| 347 | res = (void *)get_zeroed_page(gfp_mask); |
| 348 | if (res) { |
| 349 | SetPageNosave(virt_to_page(res)); |
| 350 | SetPageNosaveFree(virt_to_page(res)); |
| 351 | } |
| 352 | return res; |
| 353 | } |
| 354 | |
| 355 | unsigned long get_safe_page(gfp_t gfp_mask) |
| 356 | { |
| 357 | return (unsigned long)alloc_image_page(gfp_mask, 1); |
| 358 | } |
| 359 | |
| 360 | /** |
| 361 | * alloc_pagedir - Allocate the page directory. |
| 362 | * |
| 363 | * First, determine exactly how many pages we need and |
| 364 | * allocate them. |
| 365 | * |
| 366 | * We arrange the pages in a chain: each page is an array of PBES_PER_PAGE |
| 367 | * struct pbe elements (pbes) and the last element in the page points |
| 368 | * to the next page. |
| 369 | * |
| 370 | * On each page we set up a list of struct_pbe elements. |
| 371 | */ |
| 372 | |
| 373 | struct pbe *alloc_pagedir(unsigned int nr_pages, gfp_t gfp_mask, int safe_needed) |
| 374 | { |
| 375 | unsigned int num; |
| 376 | struct pbe *pblist, *pbe; |
| 377 | |
| 378 | if (!nr_pages) |
| 379 | return NULL; |
| 380 | |
| 381 | pr_debug("alloc_pagedir(): nr_pages = %d\n", nr_pages); |
| 382 | pblist = alloc_image_page(gfp_mask, safe_needed); |
| 383 | /* FIXME: rewrite this ugly loop */ |
| 384 | for (pbe = pblist, num = PBES_PER_PAGE; pbe && num < nr_pages; |
| 385 | pbe = pbe->next, num += PBES_PER_PAGE) { |
| 386 | pbe += PB_PAGE_SKIP; |
| 387 | pbe->next = alloc_image_page(gfp_mask, safe_needed); |
| 388 | } |
| 389 | if (!pbe) { /* get_zeroed_page() failed */ |
| 390 | free_pagedir(pblist); |
| 391 | pblist = NULL; |
| 392 | } else |
| 393 | create_pbe_list(pblist, nr_pages); |
| 394 | return pblist; |
| 395 | } |
| 396 | |
| 397 | /** |
| 398 | * Free pages we allocated for suspend. Suspend pages are alocated |
| 399 | * before atomic copy, so we need to free them after resume. |
| 400 | */ |
| 401 | |
| 402 | void swsusp_free(void) |
| 403 | { |
| 404 | struct zone *zone; |
| 405 | unsigned long zone_pfn; |
| 406 | |
| 407 | for_each_zone(zone) { |
| 408 | for (zone_pfn = 0; zone_pfn < zone->spanned_pages; ++zone_pfn) |
| 409 | if (pfn_valid(zone_pfn + zone->zone_start_pfn)) { |
| 410 | struct page *page; |
| 411 | page = pfn_to_page(zone_pfn + zone->zone_start_pfn); |
| 412 | if (PageNosave(page) && PageNosaveFree(page)) { |
| 413 | ClearPageNosave(page); |
| 414 | ClearPageNosaveFree(page); |
| 415 | free_page((long) page_address(page)); |
| 416 | } |
| 417 | } |
| 418 | } |
| 419 | } |
| 420 | |
| 421 | |
| 422 | /** |
| 423 | * enough_free_mem - Make sure we enough free memory to snapshot. |
| 424 | * |
| 425 | * Returns TRUE or FALSE after checking the number of available |
| 426 | * free pages. |
| 427 | */ |
| 428 | |
| 429 | static int enough_free_mem(unsigned int nr_pages) |
| 430 | { |
| 431 | struct zone *zone; |
| 432 | unsigned int n = 0; |
| 433 | |
| 434 | for_each_zone (zone) |
| 435 | if (!is_highmem(zone)) |
| 436 | n += zone->free_pages; |
| 437 | pr_debug("swsusp: available memory: %u pages\n", n); |
| 438 | return n > (nr_pages + PAGES_FOR_IO + |
| 439 | (nr_pages + PBES_PER_PAGE - 1) / PBES_PER_PAGE); |
| 440 | } |
| 441 | |
| 442 | int alloc_data_pages(struct pbe *pblist, gfp_t gfp_mask, int safe_needed) |
| 443 | { |
| 444 | struct pbe *p; |
| 445 | |
| 446 | for_each_pbe (p, pblist) { |
| 447 | p->address = (unsigned long)alloc_image_page(gfp_mask, safe_needed); |
| 448 | if (!p->address) |
| 449 | return -ENOMEM; |
| 450 | } |
| 451 | return 0; |
| 452 | } |
| 453 | |
| 454 | static struct pbe *swsusp_alloc(unsigned int nr_pages) |
| 455 | { |
| 456 | struct pbe *pblist; |
| 457 | |
| 458 | if (!(pblist = alloc_pagedir(nr_pages, GFP_ATOMIC | __GFP_COLD, 0))) { |
| 459 | printk(KERN_ERR "suspend: Allocating pagedir failed.\n"); |
| 460 | return NULL; |
| 461 | } |
| 462 | |
| 463 | if (alloc_data_pages(pblist, GFP_ATOMIC | __GFP_COLD, 0)) { |
| 464 | printk(KERN_ERR "suspend: Allocating image pages failed.\n"); |
| 465 | swsusp_free(); |
| 466 | return NULL; |
| 467 | } |
| 468 | |
| 469 | return pblist; |
| 470 | } |
| 471 | |
| 472 | asmlinkage int swsusp_save(void) |
| 473 | { |
| 474 | unsigned int nr_pages; |
| 475 | |
| 476 | pr_debug("swsusp: critical section: \n"); |
| 477 | |
| 478 | drain_local_pages(); |
| 479 | nr_pages = count_data_pages(); |
| 480 | printk("swsusp: Need to copy %u pages\n", nr_pages); |
| 481 | |
| 482 | pr_debug("swsusp: pages needed: %u + %lu + %u, free: %u\n", |
| 483 | nr_pages, |
| 484 | (nr_pages + PBES_PER_PAGE - 1) / PBES_PER_PAGE, |
| 485 | PAGES_FOR_IO, nr_free_pages()); |
| 486 | |
| 487 | if (!enough_free_mem(nr_pages)) { |
| 488 | printk(KERN_ERR "swsusp: Not enough free memory\n"); |
| 489 | return -ENOMEM; |
| 490 | } |
| 491 | |
| 492 | pagedir_nosave = swsusp_alloc(nr_pages); |
| 493 | if (!pagedir_nosave) |
| 494 | return -ENOMEM; |
| 495 | |
| 496 | /* During allocating of suspend pagedir, new cold pages may appear. |
| 497 | * Kill them. |
| 498 | */ |
| 499 | drain_local_pages(); |
| 500 | copy_data_pages(pagedir_nosave); |
| 501 | |
| 502 | /* |
| 503 | * End of critical section. From now on, we can write to memory, |
| 504 | * but we should not touch disk. This specially means we must _not_ |
| 505 | * touch swap space! Except we must write out our image of course. |
| 506 | */ |
| 507 | |
| 508 | nr_copy_pages = nr_pages; |
| 509 | |
| 510 | printk("swsusp: critical section/: done (%d pages copied)\n", nr_pages); |
| 511 | return 0; |
| 512 | } |