1 /* 2 * linux/kernel/power/snapshot.c 3 * 4 * This file provides system snapshot/restore functionality for swsusp. 5 * 6 * Copyright (C) 1998-2005 Pavel Machek <pavel@ucw.cz> 7 * Copyright (C) 2006 Rafael J. Wysocki <rjw@sisk.pl> 8 * 9 * This file is released under the GPLv2. 10 * 11 */ 12 13 #include <linux/version.h> 14 #include <linux/module.h> 15 #include <linux/mm.h> 16 #include <linux/suspend.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/init.h> 24 #include <linux/bootmem.h> 25 #include <linux/syscalls.h> 26 #include <linux/console.h> 27 #include <linux/highmem.h> 28 #include <linux/list.h> 29 #include <linux/slab.h> 30 #include <linux/compiler.h> 31 32 #include <asm/uaccess.h> 33 #include <asm/mmu_context.h> 34 #include <asm/pgtable.h> 35 #include <asm/tlbflush.h> 36 #include <asm/io.h> 37 38 #include "power.h" 39 40 static int swsusp_page_is_free(struct page *); 41 static void swsusp_set_page_forbidden(struct page *); 42 static void swsusp_unset_page_forbidden(struct page *); 43 44 /* 45 * Number of bytes to reserve for memory allocations made by device drivers 46 * from their ->freeze() and ->freeze_noirq() callbacks so that they don't 47 * cause image creation to fail (tunable via /sys/power/reserved_size). 48 */ 49 unsigned long reserved_size; 50 51 void __init hibernate_reserved_size_init(void) 52 { 53 reserved_size = SPARE_PAGES * PAGE_SIZE; 54 } 55 56 /* 57 * Preferred image size in bytes (tunable via /sys/power/image_size). 58 * When it is set to N, swsusp will do its best to ensure the image 59 * size will not exceed N bytes, but if that is impossible, it will 60 * try to create the smallest image possible. 61 */ 62 unsigned long image_size; 63 64 void __init hibernate_image_size_init(void) 65 { 66 image_size = ((totalram_pages * 2) / 5) * PAGE_SIZE; 67 } 68 69 /* List of PBEs needed for restoring the pages that were allocated before 70 * the suspend and included in the suspend image, but have also been 71 * allocated by the "resume" kernel, so their contents cannot be written 72 * directly to their "original" page frames. 73 */ 74 struct pbe *restore_pblist; 75 76 /* Pointer to an auxiliary buffer (1 page) */ 77 static void *buffer; 78 79 /** 80 * @safe_needed - on resume, for storing the PBE list and the image, 81 * we can only use memory pages that do not conflict with the pages 82 * used before suspend. The unsafe pages have PageNosaveFree set 83 * and we count them using unsafe_pages. 84 * 85 * Each allocated image page is marked as PageNosave and PageNosaveFree 86 * so that swsusp_free() can release it. 87 */ 88 89 #define PG_ANY 0 90 #define PG_SAFE 1 91 #define PG_UNSAFE_CLEAR 1 92 #define PG_UNSAFE_KEEP 0 93 94 static unsigned int allocated_unsafe_pages; 95 96 static void *get_image_page(gfp_t gfp_mask, int safe_needed) 97 { 98 void *res; 99 100 res = (void *)get_zeroed_page(gfp_mask); 101 if (safe_needed) 102 while (res && swsusp_page_is_free(virt_to_page(res))) { 103 /* The page is unsafe, mark it for swsusp_free() */ 104 swsusp_set_page_forbidden(virt_to_page(res)); 105 allocated_unsafe_pages++; 106 res = (void *)get_zeroed_page(gfp_mask); 107 } 108 if (res) { 109 swsusp_set_page_forbidden(virt_to_page(res)); 110 swsusp_set_page_free(virt_to_page(res)); 111 } 112 return res; 113 } 114 115 unsigned long get_safe_page(gfp_t gfp_mask) 116 { 117 return (unsigned long)get_image_page(gfp_mask, PG_SAFE); 118 } 119 120 static struct page *alloc_image_page(gfp_t gfp_mask) 121 { 122 struct page *page; 123 124 page = alloc_page(gfp_mask); 125 if (page) { 126 swsusp_set_page_forbidden(page); 127 swsusp_set_page_free(page); 128 } 129 return page; 130 } 131 132 /** 133 * free_image_page - free page represented by @addr, allocated with 134 * get_image_page (page flags set by it must be cleared) 135 */ 136 137 static inline void free_image_page(void *addr, int clear_nosave_free) 138 { 139 struct page *page; 140 141 BUG_ON(!virt_addr_valid(addr)); 142 143 page = virt_to_page(addr); 144 145 swsusp_unset_page_forbidden(page); 146 if (clear_nosave_free) 147 swsusp_unset_page_free(page); 148 149 __free_page(page); 150 } 151 152 /* struct linked_page is used to build chains of pages */ 153 154 #define LINKED_PAGE_DATA_SIZE (PAGE_SIZE - sizeof(void *)) 155 156 struct linked_page { 157 struct linked_page *next; 158 char data[LINKED_PAGE_DATA_SIZE]; 159 } __packed; 160 161 static inline void 162 free_list_of_pages(struct linked_page *list, int clear_page_nosave) 163 { 164 while (list) { 165 struct linked_page *lp = list->next; 166 167 free_image_page(list, clear_page_nosave); 168 list = lp; 169 } 170 } 171 172 /** 173 * struct chain_allocator is used for allocating small objects out of 174 * a linked list of pages called 'the chain'. 175 * 176 * The chain grows each time when there is no room for a new object in 177 * the current page. The allocated objects cannot be freed individually. 178 * It is only possible to free them all at once, by freeing the entire 179 * chain. 180 * 181 * NOTE: The chain allocator may be inefficient if the allocated objects 182 * are not much smaller than PAGE_SIZE. 183 */ 184 185 struct chain_allocator { 186 struct linked_page *chain; /* the chain */ 187 unsigned int used_space; /* total size of objects allocated out 188 * of the current page 189 */ 190 gfp_t gfp_mask; /* mask for allocating pages */ 191 int safe_needed; /* if set, only "safe" pages are allocated */ 192 }; 193 194 static void 195 chain_init(struct chain_allocator *ca, gfp_t gfp_mask, int safe_needed) 196 { 197 ca->chain = NULL; 198 ca->used_space = LINKED_PAGE_DATA_SIZE; 199 ca->gfp_mask = gfp_mask; 200 ca->safe_needed = safe_needed; 201 } 202 203 static void *chain_alloc(struct chain_allocator *ca, unsigned int size) 204 { 205 void *ret; 206 207 if (LINKED_PAGE_DATA_SIZE - ca->used_space < size) { 208 struct linked_page *lp; 209 210 lp = get_image_page(ca->gfp_mask, ca->safe_needed); 211 if (!lp) 212 return NULL; 213 214 lp->next = ca->chain; 215 ca->chain = lp; 216 ca->used_space = 0; 217 } 218 ret = ca->chain->data + ca->used_space; 219 ca->used_space += size; 220 return ret; 221 } 222 223 /** 224 * Data types related to memory bitmaps. 225 * 226 * Memory bitmap is a structure consiting of many linked lists of 227 * objects. The main list's elements are of type struct zone_bitmap 228 * and each of them corresonds to one zone. For each zone bitmap 229 * object there is a list of objects of type struct bm_block that 230 * represent each blocks of bitmap in which information is stored. 231 * 232 * struct memory_bitmap contains a pointer to the main list of zone 233 * bitmap objects, a struct bm_position used for browsing the bitmap, 234 * and a pointer to the list of pages used for allocating all of the 235 * zone bitmap objects and bitmap block objects. 236 * 237 * NOTE: It has to be possible to lay out the bitmap in memory 238 * using only allocations of order 0. Additionally, the bitmap is 239 * designed to work with arbitrary number of zones (this is over the 240 * top for now, but let's avoid making unnecessary assumptions ;-). 241 * 242 * struct zone_bitmap contains a pointer to a list of bitmap block 243 * objects and a pointer to the bitmap block object that has been 244 * most recently used for setting bits. Additionally, it contains the 245 * pfns that correspond to the start and end of the represented zone. 246 * 247 * struct bm_block contains a pointer to the memory page in which 248 * information is stored (in the form of a block of bitmap) 249 * It also contains the pfns that correspond to the start and end of 250 * the represented memory area. 251 * 252 * The memory bitmap is organized as a radix tree to guarantee fast random 253 * access to the bits. There is one radix tree for each zone (as returned 254 * from create_mem_extents). 255 * 256 * One radix tree is represented by one struct mem_zone_bm_rtree. There are 257 * two linked lists for the nodes of the tree, one for the inner nodes and 258 * one for the leave nodes. The linked leave nodes are used for fast linear 259 * access of the memory bitmap. 260 * 261 * The struct rtree_node represents one node of the radix tree. 262 */ 263 264 #define BM_END_OF_MAP (~0UL) 265 266 #define BM_BITS_PER_BLOCK (PAGE_SIZE * BITS_PER_BYTE) 267 #define BM_BLOCK_SHIFT (PAGE_SHIFT + 3) 268 #define BM_BLOCK_MASK ((1UL << BM_BLOCK_SHIFT) - 1) 269 270 /* 271 * struct rtree_node is a wrapper struct to link the nodes 272 * of the rtree together for easy linear iteration over 273 * bits and easy freeing 274 */ 275 struct rtree_node { 276 struct list_head list; 277 unsigned long *data; 278 }; 279 280 /* 281 * struct mem_zone_bm_rtree represents a bitmap used for one 282 * populated memory zone. 283 */ 284 struct mem_zone_bm_rtree { 285 struct list_head list; /* Link Zones together */ 286 struct list_head nodes; /* Radix Tree inner nodes */ 287 struct list_head leaves; /* Radix Tree leaves */ 288 unsigned long start_pfn; /* Zone start page frame */ 289 unsigned long end_pfn; /* Zone end page frame + 1 */ 290 struct rtree_node *rtree; /* Radix Tree Root */ 291 int levels; /* Number of Radix Tree Levels */ 292 unsigned int blocks; /* Number of Bitmap Blocks */ 293 }; 294 295 /* strcut bm_position is used for browsing memory bitmaps */ 296 297 struct bm_position { 298 struct mem_zone_bm_rtree *zone; 299 struct rtree_node *node; 300 unsigned long node_pfn; 301 int node_bit; 302 }; 303 304 struct memory_bitmap { 305 struct list_head zones; 306 struct linked_page *p_list; /* list of pages used to store zone 307 * bitmap objects and bitmap block 308 * objects 309 */ 310 struct bm_position cur; /* most recently used bit position */ 311 }; 312 313 /* Functions that operate on memory bitmaps */ 314 315 #define BM_ENTRIES_PER_LEVEL (PAGE_SIZE / sizeof(unsigned long)) 316 #if BITS_PER_LONG == 32 317 #define BM_RTREE_LEVEL_SHIFT (PAGE_SHIFT - 2) 318 #else 319 #define BM_RTREE_LEVEL_SHIFT (PAGE_SHIFT - 3) 320 #endif 321 #define BM_RTREE_LEVEL_MASK ((1UL << BM_RTREE_LEVEL_SHIFT) - 1) 322 323 /* 324 * alloc_rtree_node - Allocate a new node and add it to the radix tree. 325 * 326 * This function is used to allocate inner nodes as well as the 327 * leave nodes of the radix tree. It also adds the node to the 328 * corresponding linked list passed in by the *list parameter. 329 */ 330 static struct rtree_node *alloc_rtree_node(gfp_t gfp_mask, int safe_needed, 331 struct chain_allocator *ca, 332 struct list_head *list) 333 { 334 struct rtree_node *node; 335 336 node = chain_alloc(ca, sizeof(struct rtree_node)); 337 if (!node) 338 return NULL; 339 340 node->data = get_image_page(gfp_mask, safe_needed); 341 if (!node->data) 342 return NULL; 343 344 list_add_tail(&node->list, list); 345 346 return node; 347 } 348 349 /* 350 * add_rtree_block - Add a new leave node to the radix tree 351 * 352 * The leave nodes need to be allocated in order to keep the leaves 353 * linked list in order. This is guaranteed by the zone->blocks 354 * counter. 355 */ 356 static int add_rtree_block(struct mem_zone_bm_rtree *zone, gfp_t gfp_mask, 357 int safe_needed, struct chain_allocator *ca) 358 { 359 struct rtree_node *node, *block, **dst; 360 unsigned int levels_needed, block_nr; 361 int i; 362 363 block_nr = zone->blocks; 364 levels_needed = 0; 365 366 /* How many levels do we need for this block nr? */ 367 while (block_nr) { 368 levels_needed += 1; 369 block_nr >>= BM_RTREE_LEVEL_SHIFT; 370 } 371 372 /* Make sure the rtree has enough levels */ 373 for (i = zone->levels; i < levels_needed; i++) { 374 node = alloc_rtree_node(gfp_mask, safe_needed, ca, 375 &zone->nodes); 376 if (!node) 377 return -ENOMEM; 378 379 node->data[0] = (unsigned long)zone->rtree; 380 zone->rtree = node; 381 zone->levels += 1; 382 } 383 384 /* Allocate new block */ 385 block = alloc_rtree_node(gfp_mask, safe_needed, ca, &zone->leaves); 386 if (!block) 387 return -ENOMEM; 388 389 /* Now walk the rtree to insert the block */ 390 node = zone->rtree; 391 dst = &zone->rtree; 392 block_nr = zone->blocks; 393 for (i = zone->levels; i > 0; i--) { 394 int index; 395 396 if (!node) { 397 node = alloc_rtree_node(gfp_mask, safe_needed, ca, 398 &zone->nodes); 399 if (!node) 400 return -ENOMEM; 401 *dst = node; 402 } 403 404 index = block_nr >> ((i - 1) * BM_RTREE_LEVEL_SHIFT); 405 index &= BM_RTREE_LEVEL_MASK; 406 dst = (struct rtree_node **)&((*dst)->data[index]); 407 node = *dst; 408 } 409 410 zone->blocks += 1; 411 *dst = block; 412 413 return 0; 414 } 415 416 static void free_zone_bm_rtree(struct mem_zone_bm_rtree *zone, 417 int clear_nosave_free); 418 419 /* 420 * create_zone_bm_rtree - create a radix tree for one zone 421 * 422 * Allocated the mem_zone_bm_rtree structure and initializes it. 423 * This function also allocated and builds the radix tree for the 424 * zone. 425 */ 426 static struct mem_zone_bm_rtree * 427 create_zone_bm_rtree(gfp_t gfp_mask, int safe_needed, 428 struct chain_allocator *ca, 429 unsigned long start, unsigned long end) 430 { 431 struct mem_zone_bm_rtree *zone; 432 unsigned int i, nr_blocks; 433 unsigned long pages; 434 435 pages = end - start; 436 zone = chain_alloc(ca, sizeof(struct mem_zone_bm_rtree)); 437 if (!zone) 438 return NULL; 439 440 INIT_LIST_HEAD(&zone->nodes); 441 INIT_LIST_HEAD(&zone->leaves); 442 zone->start_pfn = start; 443 zone->end_pfn = end; 444 nr_blocks = DIV_ROUND_UP(pages, BM_BITS_PER_BLOCK); 445 446 for (i = 0; i < nr_blocks; i++) { 447 if (add_rtree_block(zone, gfp_mask, safe_needed, ca)) { 448 free_zone_bm_rtree(zone, PG_UNSAFE_CLEAR); 449 return NULL; 450 } 451 } 452 453 return zone; 454 } 455 456 /* 457 * free_zone_bm_rtree - Free the memory of the radix tree 458 * 459 * Free all node pages of the radix tree. The mem_zone_bm_rtree 460 * structure itself is not freed here nor are the rtree_node 461 * structs. 462 */ 463 static void free_zone_bm_rtree(struct mem_zone_bm_rtree *zone, 464 int clear_nosave_free) 465 { 466 struct rtree_node *node; 467 468 list_for_each_entry(node, &zone->nodes, list) 469 free_image_page(node->data, clear_nosave_free); 470 471 list_for_each_entry(node, &zone->leaves, list) 472 free_image_page(node->data, clear_nosave_free); 473 } 474 475 static void memory_bm_position_reset(struct memory_bitmap *bm) 476 { 477 bm->cur.zone = list_entry(bm->zones.next, struct mem_zone_bm_rtree, 478 list); 479 bm->cur.node = list_entry(bm->cur.zone->leaves.next, 480 struct rtree_node, list); 481 bm->cur.node_pfn = 0; 482 bm->cur.node_bit = 0; 483 } 484 485 static void memory_bm_free(struct memory_bitmap *bm, int clear_nosave_free); 486 487 struct mem_extent { 488 struct list_head hook; 489 unsigned long start; 490 unsigned long end; 491 }; 492 493 /** 494 * free_mem_extents - free a list of memory extents 495 * @list - list of extents to empty 496 */ 497 static void free_mem_extents(struct list_head *list) 498 { 499 struct mem_extent *ext, *aux; 500 501 list_for_each_entry_safe(ext, aux, list, hook) { 502 list_del(&ext->hook); 503 kfree(ext); 504 } 505 } 506 507 /** 508 * create_mem_extents - create a list of memory extents representing 509 * contiguous ranges of PFNs 510 * @list - list to put the extents into 511 * @gfp_mask - mask to use for memory allocations 512 */ 513 static int create_mem_extents(struct list_head *list, gfp_t gfp_mask) 514 { 515 struct zone *zone; 516 517 INIT_LIST_HEAD(list); 518 519 for_each_populated_zone(zone) { 520 unsigned long zone_start, zone_end; 521 struct mem_extent *ext, *cur, *aux; 522 523 zone_start = zone->zone_start_pfn; 524 zone_end = zone_end_pfn(zone); 525 526 list_for_each_entry(ext, list, hook) 527 if (zone_start <= ext->end) 528 break; 529 530 if (&ext->hook == list || zone_end < ext->start) { 531 /* New extent is necessary */ 532 struct mem_extent *new_ext; 533 534 new_ext = kzalloc(sizeof(struct mem_extent), gfp_mask); 535 if (!new_ext) { 536 free_mem_extents(list); 537 return -ENOMEM; 538 } 539 new_ext->start = zone_start; 540 new_ext->end = zone_end; 541 list_add_tail(&new_ext->hook, &ext->hook); 542 continue; 543 } 544 545 /* Merge this zone's range of PFNs with the existing one */ 546 if (zone_start < ext->start) 547 ext->start = zone_start; 548 if (zone_end > ext->end) 549 ext->end = zone_end; 550 551 /* More merging may be possible */ 552 cur = ext; 553 list_for_each_entry_safe_continue(cur, aux, list, hook) { 554 if (zone_end < cur->start) 555 break; 556 if (zone_end < cur->end) 557 ext->end = cur->end; 558 list_del(&cur->hook); 559 kfree(cur); 560 } 561 } 562 563 return 0; 564 } 565 566 /** 567 * memory_bm_create - allocate memory for a memory bitmap 568 */ 569 static int 570 memory_bm_create(struct memory_bitmap *bm, gfp_t gfp_mask, int safe_needed) 571 { 572 struct chain_allocator ca; 573 struct list_head mem_extents; 574 struct mem_extent *ext; 575 int error; 576 577 chain_init(&ca, gfp_mask, safe_needed); 578 INIT_LIST_HEAD(&bm->zones); 579 580 error = create_mem_extents(&mem_extents, gfp_mask); 581 if (error) 582 return error; 583 584 list_for_each_entry(ext, &mem_extents, hook) { 585 struct mem_zone_bm_rtree *zone; 586 587 zone = create_zone_bm_rtree(gfp_mask, safe_needed, &ca, 588 ext->start, ext->end); 589 if (!zone) { 590 error = -ENOMEM; 591 goto Error; 592 } 593 list_add_tail(&zone->list, &bm->zones); 594 } 595 596 bm->p_list = ca.chain; 597 memory_bm_position_reset(bm); 598 Exit: 599 free_mem_extents(&mem_extents); 600 return error; 601 602 Error: 603 bm->p_list = ca.chain; 604 memory_bm_free(bm, PG_UNSAFE_CLEAR); 605 goto Exit; 606 } 607 608 /** 609 * memory_bm_free - free memory occupied by the memory bitmap @bm 610 */ 611 static void memory_bm_free(struct memory_bitmap *bm, int clear_nosave_free) 612 { 613 struct mem_zone_bm_rtree *zone; 614 615 list_for_each_entry(zone, &bm->zones, list) 616 free_zone_bm_rtree(zone, clear_nosave_free); 617 618 free_list_of_pages(bm->p_list, clear_nosave_free); 619 620 INIT_LIST_HEAD(&bm->zones); 621 } 622 623 /** 624 * memory_bm_find_bit - Find the bit for pfn in the memory 625 * bitmap 626 * 627 * Find the bit in the bitmap @bm that corresponds to given pfn. 628 * The cur.zone, cur.block and cur.node_pfn member of @bm are 629 * updated. 630 * It walks the radix tree to find the page which contains the bit for 631 * pfn and returns the bit position in **addr and *bit_nr. 632 */ 633 static int memory_bm_find_bit(struct memory_bitmap *bm, unsigned long pfn, 634 void **addr, unsigned int *bit_nr) 635 { 636 struct mem_zone_bm_rtree *curr, *zone; 637 struct rtree_node *node; 638 int i, block_nr; 639 640 zone = bm->cur.zone; 641 642 if (pfn >= zone->start_pfn && pfn < zone->end_pfn) 643 goto zone_found; 644 645 zone = NULL; 646 647 /* Find the right zone */ 648 list_for_each_entry(curr, &bm->zones, list) { 649 if (pfn >= curr->start_pfn && pfn < curr->end_pfn) { 650 zone = curr; 651 break; 652 } 653 } 654 655 if (!zone) 656 return -EFAULT; 657 658 zone_found: 659 /* 660 * We have a zone. Now walk the radix tree to find the leave 661 * node for our pfn. 662 */ 663 664 node = bm->cur.node; 665 if (((pfn - zone->start_pfn) & ~BM_BLOCK_MASK) == bm->cur.node_pfn) 666 goto node_found; 667 668 node = zone->rtree; 669 block_nr = (pfn - zone->start_pfn) >> BM_BLOCK_SHIFT; 670 671 for (i = zone->levels; i > 0; i--) { 672 int index; 673 674 index = block_nr >> ((i - 1) * BM_RTREE_LEVEL_SHIFT); 675 index &= BM_RTREE_LEVEL_MASK; 676 BUG_ON(node->data[index] == 0); 677 node = (struct rtree_node *)node->data[index]; 678 } 679 680 node_found: 681 /* Update last position */ 682 bm->cur.zone = zone; 683 bm->cur.node = node; 684 bm->cur.node_pfn = (pfn - zone->start_pfn) & ~BM_BLOCK_MASK; 685 686 /* Set return values */ 687 *addr = node->data; 688 *bit_nr = (pfn - zone->start_pfn) & BM_BLOCK_MASK; 689 690 return 0; 691 } 692 693 static void memory_bm_set_bit(struct memory_bitmap *bm, unsigned long pfn) 694 { 695 void *addr; 696 unsigned int bit; 697 int error; 698 699 error = memory_bm_find_bit(bm, pfn, &addr, &bit); 700 BUG_ON(error); 701 set_bit(bit, addr); 702 } 703 704 static int mem_bm_set_bit_check(struct memory_bitmap *bm, unsigned long pfn) 705 { 706 void *addr; 707 unsigned int bit; 708 int error; 709 710 error = memory_bm_find_bit(bm, pfn, &addr, &bit); 711 if (!error) 712 set_bit(bit, addr); 713 714 return error; 715 } 716 717 static void memory_bm_clear_bit(struct memory_bitmap *bm, unsigned long pfn) 718 { 719 void *addr; 720 unsigned int bit; 721 int error; 722 723 error = memory_bm_find_bit(bm, pfn, &addr, &bit); 724 BUG_ON(error); 725 clear_bit(bit, addr); 726 } 727 728 static void memory_bm_clear_current(struct memory_bitmap *bm) 729 { 730 int bit; 731 732 bit = max(bm->cur.node_bit - 1, 0); 733 clear_bit(bit, bm->cur.node->data); 734 } 735 736 static int memory_bm_test_bit(struct memory_bitmap *bm, unsigned long pfn) 737 { 738 void *addr; 739 unsigned int bit; 740 int error; 741 742 error = memory_bm_find_bit(bm, pfn, &addr, &bit); 743 BUG_ON(error); 744 return test_bit(bit, addr); 745 } 746 747 static bool memory_bm_pfn_present(struct memory_bitmap *bm, unsigned long pfn) 748 { 749 void *addr; 750 unsigned int bit; 751 752 return !memory_bm_find_bit(bm, pfn, &addr, &bit); 753 } 754 755 /* 756 * rtree_next_node - Jumps to the next leave node 757 * 758 * Sets the position to the beginning of the next node in the 759 * memory bitmap. This is either the next node in the current 760 * zone's radix tree or the first node in the radix tree of the 761 * next zone. 762 * 763 * Returns true if there is a next node, false otherwise. 764 */ 765 static bool rtree_next_node(struct memory_bitmap *bm) 766 { 767 bm->cur.node = list_entry(bm->cur.node->list.next, 768 struct rtree_node, list); 769 if (&bm->cur.node->list != &bm->cur.zone->leaves) { 770 bm->cur.node_pfn += BM_BITS_PER_BLOCK; 771 bm->cur.node_bit = 0; 772 touch_softlockup_watchdog(); 773 return true; 774 } 775 776 /* No more nodes, goto next zone */ 777 bm->cur.zone = list_entry(bm->cur.zone->list.next, 778 struct mem_zone_bm_rtree, list); 779 if (&bm->cur.zone->list != &bm->zones) { 780 bm->cur.node = list_entry(bm->cur.zone->leaves.next, 781 struct rtree_node, list); 782 bm->cur.node_pfn = 0; 783 bm->cur.node_bit = 0; 784 return true; 785 } 786 787 /* No more zones */ 788 return false; 789 } 790 791 /** 792 * memory_bm_rtree_next_pfn - Find the next set bit in the bitmap @bm 793 * 794 * Starting from the last returned position this function searches 795 * for the next set bit in the memory bitmap and returns its 796 * number. If no more bit is set BM_END_OF_MAP is returned. 797 * 798 * It is required to run memory_bm_position_reset() before the 799 * first call to this function. 800 */ 801 static unsigned long memory_bm_next_pfn(struct memory_bitmap *bm) 802 { 803 unsigned long bits, pfn, pages; 804 int bit; 805 806 do { 807 pages = bm->cur.zone->end_pfn - bm->cur.zone->start_pfn; 808 bits = min(pages - bm->cur.node_pfn, BM_BITS_PER_BLOCK); 809 bit = find_next_bit(bm->cur.node->data, bits, 810 bm->cur.node_bit); 811 if (bit < bits) { 812 pfn = bm->cur.zone->start_pfn + bm->cur.node_pfn + bit; 813 bm->cur.node_bit = bit + 1; 814 return pfn; 815 } 816 } while (rtree_next_node(bm)); 817 818 return BM_END_OF_MAP; 819 } 820 821 /** 822 * This structure represents a range of page frames the contents of which 823 * should not be saved during the suspend. 824 */ 825 826 struct nosave_region { 827 struct list_head list; 828 unsigned long start_pfn; 829 unsigned long end_pfn; 830 }; 831 832 static LIST_HEAD(nosave_regions); 833 834 /** 835 * register_nosave_region - register a range of page frames the contents 836 * of which should not be saved during the suspend (to be used in the early 837 * initialization code) 838 */ 839 840 void __init 841 __register_nosave_region(unsigned long start_pfn, unsigned long end_pfn, 842 int use_kmalloc) 843 { 844 struct nosave_region *region; 845 846 if (start_pfn >= end_pfn) 847 return; 848 849 if (!list_empty(&nosave_regions)) { 850 /* Try to extend the previous region (they should be sorted) */ 851 region = list_entry(nosave_regions.prev, 852 struct nosave_region, list); 853 if (region->end_pfn == start_pfn) { 854 region->end_pfn = end_pfn; 855 goto Report; 856 } 857 } 858 if (use_kmalloc) { 859 /* during init, this shouldn't fail */ 860 region = kmalloc(sizeof(struct nosave_region), GFP_KERNEL); 861 BUG_ON(!region); 862 } else 863 /* This allocation cannot fail */ 864 region = memblock_virt_alloc(sizeof(struct nosave_region), 0); 865 region->start_pfn = start_pfn; 866 region->end_pfn = end_pfn; 867 list_add_tail(®ion->list, &nosave_regions); 868 Report: 869 printk(KERN_INFO "PM: Registered nosave memory: [mem %#010llx-%#010llx]\n", 870 (unsigned long long) start_pfn << PAGE_SHIFT, 871 ((unsigned long long) end_pfn << PAGE_SHIFT) - 1); 872 } 873 874 /* 875 * Set bits in this map correspond to the page frames the contents of which 876 * should not be saved during the suspend. 877 */ 878 static struct memory_bitmap *forbidden_pages_map; 879 880 /* Set bits in this map correspond to free page frames. */ 881 static struct memory_bitmap *free_pages_map; 882 883 /* 884 * Each page frame allocated for creating the image is marked by setting the 885 * corresponding bits in forbidden_pages_map and free_pages_map simultaneously 886 */ 887 888 void swsusp_set_page_free(struct page *page) 889 { 890 if (free_pages_map) 891 memory_bm_set_bit(free_pages_map, page_to_pfn(page)); 892 } 893 894 static int swsusp_page_is_free(struct page *page) 895 { 896 return free_pages_map ? 897 memory_bm_test_bit(free_pages_map, page_to_pfn(page)) : 0; 898 } 899 900 void swsusp_unset_page_free(struct page *page) 901 { 902 if (free_pages_map) 903 memory_bm_clear_bit(free_pages_map, page_to_pfn(page)); 904 } 905 906 static void swsusp_set_page_forbidden(struct page *page) 907 { 908 if (forbidden_pages_map) 909 memory_bm_set_bit(forbidden_pages_map, page_to_pfn(page)); 910 } 911 912 int swsusp_page_is_forbidden(struct page *page) 913 { 914 return forbidden_pages_map ? 915 memory_bm_test_bit(forbidden_pages_map, page_to_pfn(page)) : 0; 916 } 917 918 static void swsusp_unset_page_forbidden(struct page *page) 919 { 920 if (forbidden_pages_map) 921 memory_bm_clear_bit(forbidden_pages_map, page_to_pfn(page)); 922 } 923 924 /** 925 * mark_nosave_pages - set bits corresponding to the page frames the 926 * contents of which should not be saved in a given bitmap. 927 */ 928 929 static void mark_nosave_pages(struct memory_bitmap *bm) 930 { 931 struct nosave_region *region; 932 933 if (list_empty(&nosave_regions)) 934 return; 935 936 list_for_each_entry(region, &nosave_regions, list) { 937 unsigned long pfn; 938 939 pr_debug("PM: Marking nosave pages: [mem %#010llx-%#010llx]\n", 940 (unsigned long long) region->start_pfn << PAGE_SHIFT, 941 ((unsigned long long) region->end_pfn << PAGE_SHIFT) 942 - 1); 943 944 for (pfn = region->start_pfn; pfn < region->end_pfn; pfn++) 945 if (pfn_valid(pfn)) { 946 /* 947 * It is safe to ignore the result of 948 * mem_bm_set_bit_check() here, since we won't 949 * touch the PFNs for which the error is 950 * returned anyway. 951 */ 952 mem_bm_set_bit_check(bm, pfn); 953 } 954 } 955 } 956 957 static bool is_nosave_page(unsigned long pfn) 958 { 959 struct nosave_region *region; 960 961 list_for_each_entry(region, &nosave_regions, list) { 962 if (pfn >= region->start_pfn && pfn < region->end_pfn) { 963 pr_err("PM: %#010llx in e820 nosave region: " 964 "[mem %#010llx-%#010llx]\n", 965 (unsigned long long) pfn << PAGE_SHIFT, 966 (unsigned long long) region->start_pfn << PAGE_SHIFT, 967 ((unsigned long long) region->end_pfn << PAGE_SHIFT) 968 - 1); 969 return true; 970 } 971 } 972 973 return false; 974 } 975 976 /** 977 * create_basic_memory_bitmaps - create bitmaps needed for marking page 978 * frames that should not be saved and free page frames. The pointers 979 * forbidden_pages_map and free_pages_map are only modified if everything 980 * goes well, because we don't want the bits to be used before both bitmaps 981 * are set up. 982 */ 983 984 int create_basic_memory_bitmaps(void) 985 { 986 struct memory_bitmap *bm1, *bm2; 987 int error = 0; 988 989 if (forbidden_pages_map && free_pages_map) 990 return 0; 991 else 992 BUG_ON(forbidden_pages_map || free_pages_map); 993 994 bm1 = kzalloc(sizeof(struct memory_bitmap), GFP_KERNEL); 995 if (!bm1) 996 return -ENOMEM; 997 998 error = memory_bm_create(bm1, GFP_KERNEL, PG_ANY); 999 if (error) 1000 goto Free_first_object; 1001 1002 bm2 = kzalloc(sizeof(struct memory_bitmap), GFP_KERNEL); 1003 if (!bm2) 1004 goto Free_first_bitmap; 1005 1006 error = memory_bm_create(bm2, GFP_KERNEL, PG_ANY); 1007 if (error) 1008 goto Free_second_object; 1009 1010 forbidden_pages_map = bm1; 1011 free_pages_map = bm2; 1012 mark_nosave_pages(forbidden_pages_map); 1013 1014 pr_debug("PM: Basic memory bitmaps created\n"); 1015 1016 return 0; 1017 1018 Free_second_object: 1019 kfree(bm2); 1020 Free_first_bitmap: 1021 memory_bm_free(bm1, PG_UNSAFE_CLEAR); 1022 Free_first_object: 1023 kfree(bm1); 1024 return -ENOMEM; 1025 } 1026 1027 /** 1028 * free_basic_memory_bitmaps - free memory bitmaps allocated by 1029 * create_basic_memory_bitmaps(). The auxiliary pointers are necessary 1030 * so that the bitmaps themselves are not referred to while they are being 1031 * freed. 1032 */ 1033 1034 void free_basic_memory_bitmaps(void) 1035 { 1036 struct memory_bitmap *bm1, *bm2; 1037 1038 if (WARN_ON(!(forbidden_pages_map && free_pages_map))) 1039 return; 1040 1041 bm1 = forbidden_pages_map; 1042 bm2 = free_pages_map; 1043 forbidden_pages_map = NULL; 1044 free_pages_map = NULL; 1045 memory_bm_free(bm1, PG_UNSAFE_CLEAR); 1046 kfree(bm1); 1047 memory_bm_free(bm2, PG_UNSAFE_CLEAR); 1048 kfree(bm2); 1049 1050 pr_debug("PM: Basic memory bitmaps freed\n"); 1051 } 1052 1053 /** 1054 * snapshot_additional_pages - estimate the number of additional pages 1055 * be needed for setting up the suspend image data structures for given 1056 * zone (usually the returned value is greater than the exact number) 1057 */ 1058 1059 unsigned int snapshot_additional_pages(struct zone *zone) 1060 { 1061 unsigned int rtree, nodes; 1062 1063 rtree = nodes = DIV_ROUND_UP(zone->spanned_pages, BM_BITS_PER_BLOCK); 1064 rtree += DIV_ROUND_UP(rtree * sizeof(struct rtree_node), 1065 LINKED_PAGE_DATA_SIZE); 1066 while (nodes > 1) { 1067 nodes = DIV_ROUND_UP(nodes, BM_ENTRIES_PER_LEVEL); 1068 rtree += nodes; 1069 } 1070 1071 return 2 * rtree; 1072 } 1073 1074 #ifdef CONFIG_HIGHMEM 1075 /** 1076 * count_free_highmem_pages - compute the total number of free highmem 1077 * pages, system-wide. 1078 */ 1079 1080 static unsigned int count_free_highmem_pages(void) 1081 { 1082 struct zone *zone; 1083 unsigned int cnt = 0; 1084 1085 for_each_populated_zone(zone) 1086 if (is_highmem(zone)) 1087 cnt += zone_page_state(zone, NR_FREE_PAGES); 1088 1089 return cnt; 1090 } 1091 1092 /** 1093 * saveable_highmem_page - Determine whether a highmem page should be 1094 * included in the suspend image. 1095 * 1096 * We should save the page if it isn't Nosave or NosaveFree, or Reserved, 1097 * and it isn't a part of a free chunk of pages. 1098 */ 1099 static struct page *saveable_highmem_page(struct zone *zone, unsigned long pfn) 1100 { 1101 struct page *page; 1102 1103 if (!pfn_valid(pfn)) 1104 return NULL; 1105 1106 page = pfn_to_page(pfn); 1107 if (page_zone(page) != zone) 1108 return NULL; 1109 1110 BUG_ON(!PageHighMem(page)); 1111 1112 if (swsusp_page_is_forbidden(page) || swsusp_page_is_free(page) || 1113 PageReserved(page)) 1114 return NULL; 1115 1116 if (page_is_guard(page)) 1117 return NULL; 1118 1119 return page; 1120 } 1121 1122 /** 1123 * count_highmem_pages - compute the total number of saveable highmem 1124 * pages. 1125 */ 1126 1127 static unsigned int count_highmem_pages(void) 1128 { 1129 struct zone *zone; 1130 unsigned int n = 0; 1131 1132 for_each_populated_zone(zone) { 1133 unsigned long pfn, max_zone_pfn; 1134 1135 if (!is_highmem(zone)) 1136 continue; 1137 1138 mark_free_pages(zone); 1139 max_zone_pfn = zone_end_pfn(zone); 1140 for (pfn = zone->zone_start_pfn; pfn < max_zone_pfn; pfn++) 1141 if (saveable_highmem_page(zone, pfn)) 1142 n++; 1143 } 1144 return n; 1145 } 1146 #else 1147 static inline void *saveable_highmem_page(struct zone *z, unsigned long p) 1148 { 1149 return NULL; 1150 } 1151 #endif /* CONFIG_HIGHMEM */ 1152 1153 /** 1154 * saveable_page - Determine whether a non-highmem page should be included 1155 * in the suspend image. 1156 * 1157 * We should save the page if it isn't Nosave, and is not in the range 1158 * of pages statically defined as 'unsaveable', and it isn't a part of 1159 * a free chunk of pages. 1160 */ 1161 static struct page *saveable_page(struct zone *zone, unsigned long pfn) 1162 { 1163 struct page *page; 1164 1165 if (!pfn_valid(pfn)) 1166 return NULL; 1167 1168 page = pfn_to_page(pfn); 1169 if (page_zone(page) != zone) 1170 return NULL; 1171 1172 BUG_ON(PageHighMem(page)); 1173 1174 if (swsusp_page_is_forbidden(page) || swsusp_page_is_free(page)) 1175 return NULL; 1176 1177 if (PageReserved(page) 1178 && (!kernel_page_present(page) || pfn_is_nosave(pfn))) 1179 return NULL; 1180 1181 if (page_is_guard(page)) 1182 return NULL; 1183 1184 return page; 1185 } 1186 1187 /** 1188 * count_data_pages - compute the total number of saveable non-highmem 1189 * pages. 1190 */ 1191 1192 static unsigned int count_data_pages(void) 1193 { 1194 struct zone *zone; 1195 unsigned long pfn, max_zone_pfn; 1196 unsigned int n = 0; 1197 1198 for_each_populated_zone(zone) { 1199 if (is_highmem(zone)) 1200 continue; 1201 1202 mark_free_pages(zone); 1203 max_zone_pfn = zone_end_pfn(zone); 1204 for (pfn = zone->zone_start_pfn; pfn < max_zone_pfn; pfn++) 1205 if (saveable_page(zone, pfn)) 1206 n++; 1207 } 1208 return n; 1209 } 1210 1211 /* This is needed, because copy_page and memcpy are not usable for copying 1212 * task structs. 1213 */ 1214 static inline void do_copy_page(long *dst, long *src) 1215 { 1216 int n; 1217 1218 for (n = PAGE_SIZE / sizeof(long); n; n--) 1219 *dst++ = *src++; 1220 } 1221 1222 1223 /** 1224 * safe_copy_page - check if the page we are going to copy is marked as 1225 * present in the kernel page tables (this always is the case if 1226 * CONFIG_DEBUG_PAGEALLOC is not set and in that case 1227 * kernel_page_present() always returns 'true'). 1228 */ 1229 static void safe_copy_page(void *dst, struct page *s_page) 1230 { 1231 if (kernel_page_present(s_page)) { 1232 do_copy_page(dst, page_address(s_page)); 1233 } else { 1234 kernel_map_pages(s_page, 1, 1); 1235 do_copy_page(dst, page_address(s_page)); 1236 kernel_map_pages(s_page, 1, 0); 1237 } 1238 } 1239 1240 1241 #ifdef CONFIG_HIGHMEM 1242 static inline struct page * 1243 page_is_saveable(struct zone *zone, unsigned long pfn) 1244 { 1245 return is_highmem(zone) ? 1246 saveable_highmem_page(zone, pfn) : saveable_page(zone, pfn); 1247 } 1248 1249 static void copy_data_page(unsigned long dst_pfn, unsigned long src_pfn) 1250 { 1251 struct page *s_page, *d_page; 1252 void *src, *dst; 1253 1254 s_page = pfn_to_page(src_pfn); 1255 d_page = pfn_to_page(dst_pfn); 1256 if (PageHighMem(s_page)) { 1257 src = kmap_atomic(s_page); 1258 dst = kmap_atomic(d_page); 1259 do_copy_page(dst, src); 1260 kunmap_atomic(dst); 1261 kunmap_atomic(src); 1262 } else { 1263 if (PageHighMem(d_page)) { 1264 /* Page pointed to by src may contain some kernel 1265 * data modified by kmap_atomic() 1266 */ 1267 safe_copy_page(buffer, s_page); 1268 dst = kmap_atomic(d_page); 1269 copy_page(dst, buffer); 1270 kunmap_atomic(dst); 1271 } else { 1272 safe_copy_page(page_address(d_page), s_page); 1273 } 1274 } 1275 } 1276 #else 1277 #define page_is_saveable(zone, pfn) saveable_page(zone, pfn) 1278 1279 static inline void copy_data_page(unsigned long dst_pfn, unsigned long src_pfn) 1280 { 1281 safe_copy_page(page_address(pfn_to_page(dst_pfn)), 1282 pfn_to_page(src_pfn)); 1283 } 1284 #endif /* CONFIG_HIGHMEM */ 1285 1286 static void 1287 copy_data_pages(struct memory_bitmap *copy_bm, struct memory_bitmap *orig_bm) 1288 { 1289 struct zone *zone; 1290 unsigned long pfn; 1291 1292 for_each_populated_zone(zone) { 1293 unsigned long max_zone_pfn; 1294 1295 mark_free_pages(zone); 1296 max_zone_pfn = zone_end_pfn(zone); 1297 for (pfn = zone->zone_start_pfn; pfn < max_zone_pfn; pfn++) 1298 if (page_is_saveable(zone, pfn)) 1299 memory_bm_set_bit(orig_bm, pfn); 1300 } 1301 memory_bm_position_reset(orig_bm); 1302 memory_bm_position_reset(copy_bm); 1303 for(;;) { 1304 pfn = memory_bm_next_pfn(orig_bm); 1305 if (unlikely(pfn == BM_END_OF_MAP)) 1306 break; 1307 copy_data_page(memory_bm_next_pfn(copy_bm), pfn); 1308 } 1309 } 1310 1311 /* Total number of image pages */ 1312 static unsigned int nr_copy_pages; 1313 /* Number of pages needed for saving the original pfns of the image pages */ 1314 static unsigned int nr_meta_pages; 1315 /* 1316 * Numbers of normal and highmem page frames allocated for hibernation image 1317 * before suspending devices. 1318 */ 1319 unsigned int alloc_normal, alloc_highmem; 1320 /* 1321 * Memory bitmap used for marking saveable pages (during hibernation) or 1322 * hibernation image pages (during restore) 1323 */ 1324 static struct memory_bitmap orig_bm; 1325 /* 1326 * Memory bitmap used during hibernation for marking allocated page frames that 1327 * will contain copies of saveable pages. During restore it is initially used 1328 * for marking hibernation image pages, but then the set bits from it are 1329 * duplicated in @orig_bm and it is released. On highmem systems it is next 1330 * used for marking "safe" highmem pages, but it has to be reinitialized for 1331 * this purpose. 1332 */ 1333 static struct memory_bitmap copy_bm; 1334 1335 /** 1336 * swsusp_free - free pages allocated for the suspend. 1337 * 1338 * Suspend pages are alocated before the atomic copy is made, so we 1339 * need to release them after the resume. 1340 */ 1341 1342 void swsusp_free(void) 1343 { 1344 unsigned long fb_pfn, fr_pfn; 1345 1346 if (!forbidden_pages_map || !free_pages_map) 1347 goto out; 1348 1349 memory_bm_position_reset(forbidden_pages_map); 1350 memory_bm_position_reset(free_pages_map); 1351 1352 loop: 1353 fr_pfn = memory_bm_next_pfn(free_pages_map); 1354 fb_pfn = memory_bm_next_pfn(forbidden_pages_map); 1355 1356 /* 1357 * Find the next bit set in both bitmaps. This is guaranteed to 1358 * terminate when fb_pfn == fr_pfn == BM_END_OF_MAP. 1359 */ 1360 do { 1361 if (fb_pfn < fr_pfn) 1362 fb_pfn = memory_bm_next_pfn(forbidden_pages_map); 1363 if (fr_pfn < fb_pfn) 1364 fr_pfn = memory_bm_next_pfn(free_pages_map); 1365 } while (fb_pfn != fr_pfn); 1366 1367 if (fr_pfn != BM_END_OF_MAP && pfn_valid(fr_pfn)) { 1368 struct page *page = pfn_to_page(fr_pfn); 1369 1370 memory_bm_clear_current(forbidden_pages_map); 1371 memory_bm_clear_current(free_pages_map); 1372 __free_page(page); 1373 goto loop; 1374 } 1375 1376 out: 1377 nr_copy_pages = 0; 1378 nr_meta_pages = 0; 1379 restore_pblist = NULL; 1380 buffer = NULL; 1381 alloc_normal = 0; 1382 alloc_highmem = 0; 1383 } 1384 1385 /* Helper functions used for the shrinking of memory. */ 1386 1387 #define GFP_IMAGE (GFP_KERNEL | __GFP_NOWARN) 1388 1389 /** 1390 * preallocate_image_pages - Allocate a number of pages for hibernation image 1391 * @nr_pages: Number of page frames to allocate. 1392 * @mask: GFP flags to use for the allocation. 1393 * 1394 * Return value: Number of page frames actually allocated 1395 */ 1396 static unsigned long preallocate_image_pages(unsigned long nr_pages, gfp_t mask) 1397 { 1398 unsigned long nr_alloc = 0; 1399 1400 while (nr_pages > 0) { 1401 struct page *page; 1402 1403 page = alloc_image_page(mask); 1404 if (!page) 1405 break; 1406 memory_bm_set_bit(©_bm, page_to_pfn(page)); 1407 if (PageHighMem(page)) 1408 alloc_highmem++; 1409 else 1410 alloc_normal++; 1411 nr_pages--; 1412 nr_alloc++; 1413 } 1414 1415 return nr_alloc; 1416 } 1417 1418 static unsigned long preallocate_image_memory(unsigned long nr_pages, 1419 unsigned long avail_normal) 1420 { 1421 unsigned long alloc; 1422 1423 if (avail_normal <= alloc_normal) 1424 return 0; 1425 1426 alloc = avail_normal - alloc_normal; 1427 if (nr_pages < alloc) 1428 alloc = nr_pages; 1429 1430 return preallocate_image_pages(alloc, GFP_IMAGE); 1431 } 1432 1433 #ifdef CONFIG_HIGHMEM 1434 static unsigned long preallocate_image_highmem(unsigned long nr_pages) 1435 { 1436 return preallocate_image_pages(nr_pages, GFP_IMAGE | __GFP_HIGHMEM); 1437 } 1438 1439 /** 1440 * __fraction - Compute (an approximation of) x * (multiplier / base) 1441 */ 1442 static unsigned long __fraction(u64 x, u64 multiplier, u64 base) 1443 { 1444 x *= multiplier; 1445 do_div(x, base); 1446 return (unsigned long)x; 1447 } 1448 1449 static unsigned long preallocate_highmem_fraction(unsigned long nr_pages, 1450 unsigned long highmem, 1451 unsigned long total) 1452 { 1453 unsigned long alloc = __fraction(nr_pages, highmem, total); 1454 1455 return preallocate_image_pages(alloc, GFP_IMAGE | __GFP_HIGHMEM); 1456 } 1457 #else /* CONFIG_HIGHMEM */ 1458 static inline unsigned long preallocate_image_highmem(unsigned long nr_pages) 1459 { 1460 return 0; 1461 } 1462 1463 static inline unsigned long preallocate_highmem_fraction(unsigned long nr_pages, 1464 unsigned long highmem, 1465 unsigned long total) 1466 { 1467 return 0; 1468 } 1469 #endif /* CONFIG_HIGHMEM */ 1470 1471 /** 1472 * free_unnecessary_pages - Release preallocated pages not needed for the image 1473 */ 1474 static void free_unnecessary_pages(void) 1475 { 1476 unsigned long save, to_free_normal, to_free_highmem; 1477 1478 save = count_data_pages(); 1479 if (alloc_normal >= save) { 1480 to_free_normal = alloc_normal - save; 1481 save = 0; 1482 } else { 1483 to_free_normal = 0; 1484 save -= alloc_normal; 1485 } 1486 save += count_highmem_pages(); 1487 if (alloc_highmem >= save) { 1488 to_free_highmem = alloc_highmem - save; 1489 } else { 1490 to_free_highmem = 0; 1491 save -= alloc_highmem; 1492 if (to_free_normal > save) 1493 to_free_normal -= save; 1494 else 1495 to_free_normal = 0; 1496 } 1497 1498 memory_bm_position_reset(©_bm); 1499 1500 while (to_free_normal > 0 || to_free_highmem > 0) { 1501 unsigned long pfn = memory_bm_next_pfn(©_bm); 1502 struct page *page = pfn_to_page(pfn); 1503 1504 if (PageHighMem(page)) { 1505 if (!to_free_highmem) 1506 continue; 1507 to_free_highmem--; 1508 alloc_highmem--; 1509 } else { 1510 if (!to_free_normal) 1511 continue; 1512 to_free_normal--; 1513 alloc_normal--; 1514 } 1515 memory_bm_clear_bit(©_bm, pfn); 1516 swsusp_unset_page_forbidden(page); 1517 swsusp_unset_page_free(page); 1518 __free_page(page); 1519 } 1520 } 1521 1522 /** 1523 * minimum_image_size - Estimate the minimum acceptable size of an image 1524 * @saveable: Number of saveable pages in the system. 1525 * 1526 * We want to avoid attempting to free too much memory too hard, so estimate the 1527 * minimum acceptable size of a hibernation image to use as the lower limit for 1528 * preallocating memory. 1529 * 1530 * We assume that the minimum image size should be proportional to 1531 * 1532 * [number of saveable pages] - [number of pages that can be freed in theory] 1533 * 1534 * where the second term is the sum of (1) reclaimable slab pages, (2) active 1535 * and (3) inactive anonymous pages, (4) active and (5) inactive file pages, 1536 * minus mapped file pages. 1537 */ 1538 static unsigned long minimum_image_size(unsigned long saveable) 1539 { 1540 unsigned long size; 1541 1542 size = global_page_state(NR_SLAB_RECLAIMABLE) 1543 + global_page_state(NR_ACTIVE_ANON) 1544 + global_page_state(NR_INACTIVE_ANON) 1545 + global_page_state(NR_ACTIVE_FILE) 1546 + global_page_state(NR_INACTIVE_FILE) 1547 - global_page_state(NR_FILE_MAPPED); 1548 1549 return saveable <= size ? 0 : saveable - size; 1550 } 1551 1552 /** 1553 * hibernate_preallocate_memory - Preallocate memory for hibernation image 1554 * 1555 * To create a hibernation image it is necessary to make a copy of every page 1556 * frame in use. We also need a number of page frames to be free during 1557 * hibernation for allocations made while saving the image and for device 1558 * drivers, in case they need to allocate memory from their hibernation 1559 * callbacks (these two numbers are given by PAGES_FOR_IO (which is a rough 1560 * estimate) and reserverd_size divided by PAGE_SIZE (which is tunable through 1561 * /sys/power/reserved_size, respectively). To make this happen, we compute the 1562 * total number of available page frames and allocate at least 1563 * 1564 * ([page frames total] + PAGES_FOR_IO + [metadata pages]) / 2 1565 * + 2 * DIV_ROUND_UP(reserved_size, PAGE_SIZE) 1566 * 1567 * of them, which corresponds to the maximum size of a hibernation image. 1568 * 1569 * If image_size is set below the number following from the above formula, 1570 * the preallocation of memory is continued until the total number of saveable 1571 * pages in the system is below the requested image size or the minimum 1572 * acceptable image size returned by minimum_image_size(), whichever is greater. 1573 */ 1574 int hibernate_preallocate_memory(void) 1575 { 1576 struct zone *zone; 1577 unsigned long saveable, size, max_size, count, highmem, pages = 0; 1578 unsigned long alloc, save_highmem, pages_highmem, avail_normal; 1579 struct timeval start, stop; 1580 int error; 1581 1582 printk(KERN_INFO "PM: Preallocating image memory... "); 1583 do_gettimeofday(&start); 1584 1585 error = memory_bm_create(&orig_bm, GFP_IMAGE, PG_ANY); 1586 if (error) 1587 goto err_out; 1588 1589 error = memory_bm_create(©_bm, GFP_IMAGE, PG_ANY); 1590 if (error) 1591 goto err_out; 1592 1593 alloc_normal = 0; 1594 alloc_highmem = 0; 1595 1596 /* Count the number of saveable data pages. */ 1597 save_highmem = count_highmem_pages(); 1598 saveable = count_data_pages(); 1599 1600 /* 1601 * Compute the total number of page frames we can use (count) and the 1602 * number of pages needed for image metadata (size). 1603 */ 1604 count = saveable; 1605 saveable += save_highmem; 1606 highmem = save_highmem; 1607 size = 0; 1608 for_each_populated_zone(zone) { 1609 size += snapshot_additional_pages(zone); 1610 if (is_highmem(zone)) 1611 highmem += zone_page_state(zone, NR_FREE_PAGES); 1612 else 1613 count += zone_page_state(zone, NR_FREE_PAGES); 1614 } 1615 avail_normal = count; 1616 count += highmem; 1617 count -= totalreserve_pages; 1618 1619 /* Add number of pages required for page keys (s390 only). */ 1620 size += page_key_additional_pages(saveable); 1621 1622 /* Compute the maximum number of saveable pages to leave in memory. */ 1623 max_size = (count - (size + PAGES_FOR_IO)) / 2 1624 - 2 * DIV_ROUND_UP(reserved_size, PAGE_SIZE); 1625 /* Compute the desired number of image pages specified by image_size. */ 1626 size = DIV_ROUND_UP(image_size, PAGE_SIZE); 1627 if (size > max_size) 1628 size = max_size; 1629 /* 1630 * If the desired number of image pages is at least as large as the 1631 * current number of saveable pages in memory, allocate page frames for 1632 * the image and we're done. 1633 */ 1634 if (size >= saveable) { 1635 pages = preallocate_image_highmem(save_highmem); 1636 pages += preallocate_image_memory(saveable - pages, avail_normal); 1637 goto out; 1638 } 1639 1640 /* Estimate the minimum size of the image. */ 1641 pages = minimum_image_size(saveable); 1642 /* 1643 * To avoid excessive pressure on the normal zone, leave room in it to 1644 * accommodate an image of the minimum size (unless it's already too 1645 * small, in which case don't preallocate pages from it at all). 1646 */ 1647 if (avail_normal > pages) 1648 avail_normal -= pages; 1649 else 1650 avail_normal = 0; 1651 if (size < pages) 1652 size = min_t(unsigned long, pages, max_size); 1653 1654 /* 1655 * Let the memory management subsystem know that we're going to need a 1656 * large number of page frames to allocate and make it free some memory. 1657 * NOTE: If this is not done, performance will be hurt badly in some 1658 * test cases. 1659 */ 1660 shrink_all_memory(saveable - size); 1661 1662 /* 1663 * The number of saveable pages in memory was too high, so apply some 1664 * pressure to decrease it. First, make room for the largest possible 1665 * image and fail if that doesn't work. Next, try to decrease the size 1666 * of the image as much as indicated by 'size' using allocations from 1667 * highmem and non-highmem zones separately. 1668 */ 1669 pages_highmem = preallocate_image_highmem(highmem / 2); 1670 alloc = count - max_size; 1671 if (alloc > pages_highmem) 1672 alloc -= pages_highmem; 1673 else 1674 alloc = 0; 1675 pages = preallocate_image_memory(alloc, avail_normal); 1676 if (pages < alloc) { 1677 /* We have exhausted non-highmem pages, try highmem. */ 1678 alloc -= pages; 1679 pages += pages_highmem; 1680 pages_highmem = preallocate_image_highmem(alloc); 1681 if (pages_highmem < alloc) 1682 goto err_out; 1683 pages += pages_highmem; 1684 /* 1685 * size is the desired number of saveable pages to leave in 1686 * memory, so try to preallocate (all memory - size) pages. 1687 */ 1688 alloc = (count - pages) - size; 1689 pages += preallocate_image_highmem(alloc); 1690 } else { 1691 /* 1692 * There are approximately max_size saveable pages at this point 1693 * and we want to reduce this number down to size. 1694 */ 1695 alloc = max_size - size; 1696 size = preallocate_highmem_fraction(alloc, highmem, count); 1697 pages_highmem += size; 1698 alloc -= size; 1699 size = preallocate_image_memory(alloc, avail_normal); 1700 pages_highmem += preallocate_image_highmem(alloc - size); 1701 pages += pages_highmem + size; 1702 } 1703 1704 /* 1705 * We only need as many page frames for the image as there are saveable 1706 * pages in memory, but we have allocated more. Release the excessive 1707 * ones now. 1708 */ 1709 free_unnecessary_pages(); 1710 1711 out: 1712 do_gettimeofday(&stop); 1713 printk(KERN_CONT "done (allocated %lu pages)\n", pages); 1714 swsusp_show_speed(&start, &stop, pages, "Allocated"); 1715 1716 return 0; 1717 1718 err_out: 1719 printk(KERN_CONT "\n"); 1720 swsusp_free(); 1721 return -ENOMEM; 1722 } 1723 1724 #ifdef CONFIG_HIGHMEM 1725 /** 1726 * count_pages_for_highmem - compute the number of non-highmem pages 1727 * that will be necessary for creating copies of highmem pages. 1728 */ 1729 1730 static unsigned int count_pages_for_highmem(unsigned int nr_highmem) 1731 { 1732 unsigned int free_highmem = count_free_highmem_pages() + alloc_highmem; 1733 1734 if (free_highmem >= nr_highmem) 1735 nr_highmem = 0; 1736 else 1737 nr_highmem -= free_highmem; 1738 1739 return nr_highmem; 1740 } 1741 #else 1742 static unsigned int 1743 count_pages_for_highmem(unsigned int nr_highmem) { return 0; } 1744 #endif /* CONFIG_HIGHMEM */ 1745 1746 /** 1747 * enough_free_mem - Make sure we have enough free memory for the 1748 * snapshot image. 1749 */ 1750 1751 static int enough_free_mem(unsigned int nr_pages, unsigned int nr_highmem) 1752 { 1753 struct zone *zone; 1754 unsigned int free = alloc_normal; 1755 1756 for_each_populated_zone(zone) 1757 if (!is_highmem(zone)) 1758 free += zone_page_state(zone, NR_FREE_PAGES); 1759 1760 nr_pages += count_pages_for_highmem(nr_highmem); 1761 pr_debug("PM: Normal pages needed: %u + %u, available pages: %u\n", 1762 nr_pages, PAGES_FOR_IO, free); 1763 1764 return free > nr_pages + PAGES_FOR_IO; 1765 } 1766 1767 #ifdef CONFIG_HIGHMEM 1768 /** 1769 * get_highmem_buffer - if there are some highmem pages in the suspend 1770 * image, we may need the buffer to copy them and/or load their data. 1771 */ 1772 1773 static inline int get_highmem_buffer(int safe_needed) 1774 { 1775 buffer = get_image_page(GFP_ATOMIC | __GFP_COLD, safe_needed); 1776 return buffer ? 0 : -ENOMEM; 1777 } 1778 1779 /** 1780 * alloc_highmem_image_pages - allocate some highmem pages for the image. 1781 * Try to allocate as many pages as needed, but if the number of free 1782 * highmem pages is lesser than that, allocate them all. 1783 */ 1784 1785 static inline unsigned int 1786 alloc_highmem_pages(struct memory_bitmap *bm, unsigned int nr_highmem) 1787 { 1788 unsigned int to_alloc = count_free_highmem_pages(); 1789 1790 if (to_alloc > nr_highmem) 1791 to_alloc = nr_highmem; 1792 1793 nr_highmem -= to_alloc; 1794 while (to_alloc-- > 0) { 1795 struct page *page; 1796 1797 page = alloc_image_page(__GFP_HIGHMEM); 1798 memory_bm_set_bit(bm, page_to_pfn(page)); 1799 } 1800 return nr_highmem; 1801 } 1802 #else 1803 static inline int get_highmem_buffer(int safe_needed) { return 0; } 1804 1805 static inline unsigned int 1806 alloc_highmem_pages(struct memory_bitmap *bm, unsigned int n) { return 0; } 1807 #endif /* CONFIG_HIGHMEM */ 1808 1809 /** 1810 * swsusp_alloc - allocate memory for the suspend image 1811 * 1812 * We first try to allocate as many highmem pages as there are 1813 * saveable highmem pages in the system. If that fails, we allocate 1814 * non-highmem pages for the copies of the remaining highmem ones. 1815 * 1816 * In this approach it is likely that the copies of highmem pages will 1817 * also be located in the high memory, because of the way in which 1818 * copy_data_pages() works. 1819 */ 1820 1821 static int 1822 swsusp_alloc(struct memory_bitmap *orig_bm, struct memory_bitmap *copy_bm, 1823 unsigned int nr_pages, unsigned int nr_highmem) 1824 { 1825 if (nr_highmem > 0) { 1826 if (get_highmem_buffer(PG_ANY)) 1827 goto err_out; 1828 if (nr_highmem > alloc_highmem) { 1829 nr_highmem -= alloc_highmem; 1830 nr_pages += alloc_highmem_pages(copy_bm, nr_highmem); 1831 } 1832 } 1833 if (nr_pages > alloc_normal) { 1834 nr_pages -= alloc_normal; 1835 while (nr_pages-- > 0) { 1836 struct page *page; 1837 1838 page = alloc_image_page(GFP_ATOMIC | __GFP_COLD); 1839 if (!page) 1840 goto err_out; 1841 memory_bm_set_bit(copy_bm, page_to_pfn(page)); 1842 } 1843 } 1844 1845 return 0; 1846 1847 err_out: 1848 swsusp_free(); 1849 return -ENOMEM; 1850 } 1851 1852 asmlinkage __visible int swsusp_save(void) 1853 { 1854 unsigned int nr_pages, nr_highmem; 1855 1856 printk(KERN_INFO "PM: Creating hibernation image:\n"); 1857 1858 drain_local_pages(NULL); 1859 nr_pages = count_data_pages(); 1860 nr_highmem = count_highmem_pages(); 1861 printk(KERN_INFO "PM: Need to copy %u pages\n", nr_pages + nr_highmem); 1862 1863 if (!enough_free_mem(nr_pages, nr_highmem)) { 1864 printk(KERN_ERR "PM: Not enough free memory\n"); 1865 return -ENOMEM; 1866 } 1867 1868 if (swsusp_alloc(&orig_bm, ©_bm, nr_pages, nr_highmem)) { 1869 printk(KERN_ERR "PM: Memory allocation failed\n"); 1870 return -ENOMEM; 1871 } 1872 1873 /* During allocating of suspend pagedir, new cold pages may appear. 1874 * Kill them. 1875 */ 1876 drain_local_pages(NULL); 1877 copy_data_pages(©_bm, &orig_bm); 1878 1879 /* 1880 * End of critical section. From now on, we can write to memory, 1881 * but we should not touch disk. This specially means we must _not_ 1882 * touch swap space! Except we must write out our image of course. 1883 */ 1884 1885 nr_pages += nr_highmem; 1886 nr_copy_pages = nr_pages; 1887 nr_meta_pages = DIV_ROUND_UP(nr_pages * sizeof(long), PAGE_SIZE); 1888 1889 printk(KERN_INFO "PM: Hibernation image created (%d pages copied)\n", 1890 nr_pages); 1891 1892 return 0; 1893 } 1894 1895 #ifndef CONFIG_ARCH_HIBERNATION_HEADER 1896 static int init_header_complete(struct swsusp_info *info) 1897 { 1898 memcpy(&info->uts, init_utsname(), sizeof(struct new_utsname)); 1899 info->version_code = LINUX_VERSION_CODE; 1900 return 0; 1901 } 1902 1903 static char *check_image_kernel(struct swsusp_info *info) 1904 { 1905 if (info->version_code != LINUX_VERSION_CODE) 1906 return "kernel version"; 1907 if (strcmp(info->uts.sysname,init_utsname()->sysname)) 1908 return "system type"; 1909 if (strcmp(info->uts.release,init_utsname()->release)) 1910 return "kernel release"; 1911 if (strcmp(info->uts.version,init_utsname()->version)) 1912 return "version"; 1913 if (strcmp(info->uts.machine,init_utsname()->machine)) 1914 return "machine"; 1915 return NULL; 1916 } 1917 #endif /* CONFIG_ARCH_HIBERNATION_HEADER */ 1918 1919 unsigned long snapshot_get_image_size(void) 1920 { 1921 return nr_copy_pages + nr_meta_pages + 1; 1922 } 1923 1924 static int init_header(struct swsusp_info *info) 1925 { 1926 memset(info, 0, sizeof(struct swsusp_info)); 1927 info->num_physpages = get_num_physpages(); 1928 info->image_pages = nr_copy_pages; 1929 info->pages = snapshot_get_image_size(); 1930 info->size = info->pages; 1931 info->size <<= PAGE_SHIFT; 1932 return init_header_complete(info); 1933 } 1934 1935 /** 1936 * pack_pfns - pfns corresponding to the set bits found in the bitmap @bm 1937 * are stored in the array @buf[] (1 page at a time) 1938 */ 1939 1940 static inline void 1941 pack_pfns(unsigned long *buf, struct memory_bitmap *bm) 1942 { 1943 int j; 1944 1945 for (j = 0; j < PAGE_SIZE / sizeof(long); j++) { 1946 buf[j] = memory_bm_next_pfn(bm); 1947 if (unlikely(buf[j] == BM_END_OF_MAP)) 1948 break; 1949 /* Save page key for data page (s390 only). */ 1950 page_key_read(buf + j); 1951 } 1952 } 1953 1954 /** 1955 * snapshot_read_next - used for reading the system memory snapshot. 1956 * 1957 * On the first call to it @handle should point to a zeroed 1958 * snapshot_handle structure. The structure gets updated and a pointer 1959 * to it should be passed to this function every next time. 1960 * 1961 * On success the function returns a positive number. Then, the caller 1962 * is allowed to read up to the returned number of bytes from the memory 1963 * location computed by the data_of() macro. 1964 * 1965 * The function returns 0 to indicate the end of data stream condition, 1966 * and a negative number is returned on error. In such cases the 1967 * structure pointed to by @handle is not updated and should not be used 1968 * any more. 1969 */ 1970 1971 int snapshot_read_next(struct snapshot_handle *handle) 1972 { 1973 if (handle->cur > nr_meta_pages + nr_copy_pages) 1974 return 0; 1975 1976 if (!buffer) { 1977 /* This makes the buffer be freed by swsusp_free() */ 1978 buffer = get_image_page(GFP_ATOMIC, PG_ANY); 1979 if (!buffer) 1980 return -ENOMEM; 1981 } 1982 if (!handle->cur) { 1983 int error; 1984 1985 error = init_header((struct swsusp_info *)buffer); 1986 if (error) 1987 return error; 1988 handle->buffer = buffer; 1989 memory_bm_position_reset(&orig_bm); 1990 memory_bm_position_reset(©_bm); 1991 } else if (handle->cur <= nr_meta_pages) { 1992 clear_page(buffer); 1993 pack_pfns(buffer, &orig_bm); 1994 } else { 1995 struct page *page; 1996 1997 page = pfn_to_page(memory_bm_next_pfn(©_bm)); 1998 if (PageHighMem(page)) { 1999 /* Highmem pages are copied to the buffer, 2000 * because we can't return with a kmapped 2001 * highmem page (we may not be called again). 2002 */ 2003 void *kaddr; 2004 2005 kaddr = kmap_atomic(page); 2006 copy_page(buffer, kaddr); 2007 kunmap_atomic(kaddr); 2008 handle->buffer = buffer; 2009 } else { 2010 handle->buffer = page_address(page); 2011 } 2012 } 2013 handle->cur++; 2014 return PAGE_SIZE; 2015 } 2016 2017 /** 2018 * mark_unsafe_pages - mark the pages that cannot be used for storing 2019 * the image during resume, because they conflict with the pages that 2020 * had been used before suspend 2021 */ 2022 2023 static int mark_unsafe_pages(struct memory_bitmap *bm) 2024 { 2025 struct zone *zone; 2026 unsigned long pfn, max_zone_pfn; 2027 2028 /* Clear page flags */ 2029 for_each_populated_zone(zone) { 2030 max_zone_pfn = zone_end_pfn(zone); 2031 for (pfn = zone->zone_start_pfn; pfn < max_zone_pfn; pfn++) 2032 if (pfn_valid(pfn)) 2033 swsusp_unset_page_free(pfn_to_page(pfn)); 2034 } 2035 2036 /* Mark pages that correspond to the "original" pfns as "unsafe" */ 2037 memory_bm_position_reset(bm); 2038 do { 2039 pfn = memory_bm_next_pfn(bm); 2040 if (likely(pfn != BM_END_OF_MAP)) { 2041 if (likely(pfn_valid(pfn)) && !is_nosave_page(pfn)) 2042 swsusp_set_page_free(pfn_to_page(pfn)); 2043 else 2044 return -EFAULT; 2045 } 2046 } while (pfn != BM_END_OF_MAP); 2047 2048 allocated_unsafe_pages = 0; 2049 2050 return 0; 2051 } 2052 2053 static void 2054 duplicate_memory_bitmap(struct memory_bitmap *dst, struct memory_bitmap *src) 2055 { 2056 unsigned long pfn; 2057 2058 memory_bm_position_reset(src); 2059 pfn = memory_bm_next_pfn(src); 2060 while (pfn != BM_END_OF_MAP) { 2061 memory_bm_set_bit(dst, pfn); 2062 pfn = memory_bm_next_pfn(src); 2063 } 2064 } 2065 2066 static int check_header(struct swsusp_info *info) 2067 { 2068 char *reason; 2069 2070 reason = check_image_kernel(info); 2071 if (!reason && info->num_physpages != get_num_physpages()) 2072 reason = "memory size"; 2073 if (reason) { 2074 printk(KERN_ERR "PM: Image mismatch: %s\n", reason); 2075 return -EPERM; 2076 } 2077 return 0; 2078 } 2079 2080 /** 2081 * load header - check the image header and copy data from it 2082 */ 2083 2084 static int 2085 load_header(struct swsusp_info *info) 2086 { 2087 int error; 2088 2089 restore_pblist = NULL; 2090 error = check_header(info); 2091 if (!error) { 2092 nr_copy_pages = info->image_pages; 2093 nr_meta_pages = info->pages - info->image_pages - 1; 2094 } 2095 return error; 2096 } 2097 2098 /** 2099 * unpack_orig_pfns - for each element of @buf[] (1 page at a time) set 2100 * the corresponding bit in the memory bitmap @bm 2101 */ 2102 static int unpack_orig_pfns(unsigned long *buf, struct memory_bitmap *bm) 2103 { 2104 int j; 2105 2106 for (j = 0; j < PAGE_SIZE / sizeof(long); j++) { 2107 if (unlikely(buf[j] == BM_END_OF_MAP)) 2108 break; 2109 2110 /* Extract and buffer page key for data page (s390 only). */ 2111 page_key_memorize(buf + j); 2112 2113 if (memory_bm_pfn_present(bm, buf[j])) 2114 memory_bm_set_bit(bm, buf[j]); 2115 else 2116 return -EFAULT; 2117 } 2118 2119 return 0; 2120 } 2121 2122 /* List of "safe" pages that may be used to store data loaded from the suspend 2123 * image 2124 */ 2125 static struct linked_page *safe_pages_list; 2126 2127 #ifdef CONFIG_HIGHMEM 2128 /* struct highmem_pbe is used for creating the list of highmem pages that 2129 * should be restored atomically during the resume from disk, because the page 2130 * frames they have occupied before the suspend are in use. 2131 */ 2132 struct highmem_pbe { 2133 struct page *copy_page; /* data is here now */ 2134 struct page *orig_page; /* data was here before the suspend */ 2135 struct highmem_pbe *next; 2136 }; 2137 2138 /* List of highmem PBEs needed for restoring the highmem pages that were 2139 * allocated before the suspend and included in the suspend image, but have 2140 * also been allocated by the "resume" kernel, so their contents cannot be 2141 * written directly to their "original" page frames. 2142 */ 2143 static struct highmem_pbe *highmem_pblist; 2144 2145 /** 2146 * count_highmem_image_pages - compute the number of highmem pages in the 2147 * suspend image. The bits in the memory bitmap @bm that correspond to the 2148 * image pages are assumed to be set. 2149 */ 2150 2151 static unsigned int count_highmem_image_pages(struct memory_bitmap *bm) 2152 { 2153 unsigned long pfn; 2154 unsigned int cnt = 0; 2155 2156 memory_bm_position_reset(bm); 2157 pfn = memory_bm_next_pfn(bm); 2158 while (pfn != BM_END_OF_MAP) { 2159 if (PageHighMem(pfn_to_page(pfn))) 2160 cnt++; 2161 2162 pfn = memory_bm_next_pfn(bm); 2163 } 2164 return cnt; 2165 } 2166 2167 /** 2168 * prepare_highmem_image - try to allocate as many highmem pages as 2169 * there are highmem image pages (@nr_highmem_p points to the variable 2170 * containing the number of highmem image pages). The pages that are 2171 * "safe" (ie. will not be overwritten when the suspend image is 2172 * restored) have the corresponding bits set in @bm (it must be 2173 * unitialized). 2174 * 2175 * NOTE: This function should not be called if there are no highmem 2176 * image pages. 2177 */ 2178 2179 static unsigned int safe_highmem_pages; 2180 2181 static struct memory_bitmap *safe_highmem_bm; 2182 2183 static int 2184 prepare_highmem_image(struct memory_bitmap *bm, unsigned int *nr_highmem_p) 2185 { 2186 unsigned int to_alloc; 2187 2188 if (memory_bm_create(bm, GFP_ATOMIC, PG_SAFE)) 2189 return -ENOMEM; 2190 2191 if (get_highmem_buffer(PG_SAFE)) 2192 return -ENOMEM; 2193 2194 to_alloc = count_free_highmem_pages(); 2195 if (to_alloc > *nr_highmem_p) 2196 to_alloc = *nr_highmem_p; 2197 else 2198 *nr_highmem_p = to_alloc; 2199 2200 safe_highmem_pages = 0; 2201 while (to_alloc-- > 0) { 2202 struct page *page; 2203 2204 page = alloc_page(__GFP_HIGHMEM); 2205 if (!swsusp_page_is_free(page)) { 2206 /* The page is "safe", set its bit the bitmap */ 2207 memory_bm_set_bit(bm, page_to_pfn(page)); 2208 safe_highmem_pages++; 2209 } 2210 /* Mark the page as allocated */ 2211 swsusp_set_page_forbidden(page); 2212 swsusp_set_page_free(page); 2213 } 2214 memory_bm_position_reset(bm); 2215 safe_highmem_bm = bm; 2216 return 0; 2217 } 2218 2219 /** 2220 * get_highmem_page_buffer - for given highmem image page find the buffer 2221 * that suspend_write_next() should set for its caller to write to. 2222 * 2223 * If the page is to be saved to its "original" page frame or a copy of 2224 * the page is to be made in the highmem, @buffer is returned. Otherwise, 2225 * the copy of the page is to be made in normal memory, so the address of 2226 * the copy is returned. 2227 * 2228 * If @buffer is returned, the caller of suspend_write_next() will write 2229 * the page's contents to @buffer, so they will have to be copied to the 2230 * right location on the next call to suspend_write_next() and it is done 2231 * with the help of copy_last_highmem_page(). For this purpose, if 2232 * @buffer is returned, @last_highmem page is set to the page to which 2233 * the data will have to be copied from @buffer. 2234 */ 2235 2236 static struct page *last_highmem_page; 2237 2238 static void * 2239 get_highmem_page_buffer(struct page *page, struct chain_allocator *ca) 2240 { 2241 struct highmem_pbe *pbe; 2242 void *kaddr; 2243 2244 if (swsusp_page_is_forbidden(page) && swsusp_page_is_free(page)) { 2245 /* We have allocated the "original" page frame and we can 2246 * use it directly to store the loaded page. 2247 */ 2248 last_highmem_page = page; 2249 return buffer; 2250 } 2251 /* The "original" page frame has not been allocated and we have to 2252 * use a "safe" page frame to store the loaded page. 2253 */ 2254 pbe = chain_alloc(ca, sizeof(struct highmem_pbe)); 2255 if (!pbe) { 2256 swsusp_free(); 2257 return ERR_PTR(-ENOMEM); 2258 } 2259 pbe->orig_page = page; 2260 if (safe_highmem_pages > 0) { 2261 struct page *tmp; 2262 2263 /* Copy of the page will be stored in high memory */ 2264 kaddr = buffer; 2265 tmp = pfn_to_page(memory_bm_next_pfn(safe_highmem_bm)); 2266 safe_highmem_pages--; 2267 last_highmem_page = tmp; 2268 pbe->copy_page = tmp; 2269 } else { 2270 /* Copy of the page will be stored in normal memory */ 2271 kaddr = safe_pages_list; 2272 safe_pages_list = safe_pages_list->next; 2273 pbe->copy_page = virt_to_page(kaddr); 2274 } 2275 pbe->next = highmem_pblist; 2276 highmem_pblist = pbe; 2277 return kaddr; 2278 } 2279 2280 /** 2281 * copy_last_highmem_page - copy the contents of a highmem image from 2282 * @buffer, where the caller of snapshot_write_next() has place them, 2283 * to the right location represented by @last_highmem_page . 2284 */ 2285 2286 static void copy_last_highmem_page(void) 2287 { 2288 if (last_highmem_page) { 2289 void *dst; 2290 2291 dst = kmap_atomic(last_highmem_page); 2292 copy_page(dst, buffer); 2293 kunmap_atomic(dst); 2294 last_highmem_page = NULL; 2295 } 2296 } 2297 2298 static inline int last_highmem_page_copied(void) 2299 { 2300 return !last_highmem_page; 2301 } 2302 2303 static inline void free_highmem_data(void) 2304 { 2305 if (safe_highmem_bm) 2306 memory_bm_free(safe_highmem_bm, PG_UNSAFE_CLEAR); 2307 2308 if (buffer) 2309 free_image_page(buffer, PG_UNSAFE_CLEAR); 2310 } 2311 #else 2312 static inline int get_safe_write_buffer(void) { return 0; } 2313 2314 static unsigned int 2315 count_highmem_image_pages(struct memory_bitmap *bm) { return 0; } 2316 2317 static inline int 2318 prepare_highmem_image(struct memory_bitmap *bm, unsigned int *nr_highmem_p) 2319 { 2320 return 0; 2321 } 2322 2323 static inline void * 2324 get_highmem_page_buffer(struct page *page, struct chain_allocator *ca) 2325 { 2326 return ERR_PTR(-EINVAL); 2327 } 2328 2329 static inline void copy_last_highmem_page(void) {} 2330 static inline int last_highmem_page_copied(void) { return 1; } 2331 static inline void free_highmem_data(void) {} 2332 #endif /* CONFIG_HIGHMEM */ 2333 2334 /** 2335 * prepare_image - use the memory bitmap @bm to mark the pages that will 2336 * be overwritten in the process of restoring the system memory state 2337 * from the suspend image ("unsafe" pages) and allocate memory for the 2338 * image. 2339 * 2340 * The idea is to allocate a new memory bitmap first and then allocate 2341 * as many pages as needed for the image data, but not to assign these 2342 * pages to specific tasks initially. Instead, we just mark them as 2343 * allocated and create a lists of "safe" pages that will be used 2344 * later. On systems with high memory a list of "safe" highmem pages is 2345 * also created. 2346 */ 2347 2348 #define PBES_PER_LINKED_PAGE (LINKED_PAGE_DATA_SIZE / sizeof(struct pbe)) 2349 2350 static int 2351 prepare_image(struct memory_bitmap *new_bm, struct memory_bitmap *bm) 2352 { 2353 unsigned int nr_pages, nr_highmem; 2354 struct linked_page *sp_list, *lp; 2355 int error; 2356 2357 /* If there is no highmem, the buffer will not be necessary */ 2358 free_image_page(buffer, PG_UNSAFE_CLEAR); 2359 buffer = NULL; 2360 2361 nr_highmem = count_highmem_image_pages(bm); 2362 error = mark_unsafe_pages(bm); 2363 if (error) 2364 goto Free; 2365 2366 error = memory_bm_create(new_bm, GFP_ATOMIC, PG_SAFE); 2367 if (error) 2368 goto Free; 2369 2370 duplicate_memory_bitmap(new_bm, bm); 2371 memory_bm_free(bm, PG_UNSAFE_KEEP); 2372 if (nr_highmem > 0) { 2373 error = prepare_highmem_image(bm, &nr_highmem); 2374 if (error) 2375 goto Free; 2376 } 2377 /* Reserve some safe pages for potential later use. 2378 * 2379 * NOTE: This way we make sure there will be enough safe pages for the 2380 * chain_alloc() in get_buffer(). It is a bit wasteful, but 2381 * nr_copy_pages cannot be greater than 50% of the memory anyway. 2382 */ 2383 sp_list = NULL; 2384 /* nr_copy_pages cannot be lesser than allocated_unsafe_pages */ 2385 nr_pages = nr_copy_pages - nr_highmem - allocated_unsafe_pages; 2386 nr_pages = DIV_ROUND_UP(nr_pages, PBES_PER_LINKED_PAGE); 2387 while (nr_pages > 0) { 2388 lp = get_image_page(GFP_ATOMIC, PG_SAFE); 2389 if (!lp) { 2390 error = -ENOMEM; 2391 goto Free; 2392 } 2393 lp->next = sp_list; 2394 sp_list = lp; 2395 nr_pages--; 2396 } 2397 /* Preallocate memory for the image */ 2398 safe_pages_list = NULL; 2399 nr_pages = nr_copy_pages - nr_highmem - allocated_unsafe_pages; 2400 while (nr_pages > 0) { 2401 lp = (struct linked_page *)get_zeroed_page(GFP_ATOMIC); 2402 if (!lp) { 2403 error = -ENOMEM; 2404 goto Free; 2405 } 2406 if (!swsusp_page_is_free(virt_to_page(lp))) { 2407 /* The page is "safe", add it to the list */ 2408 lp->next = safe_pages_list; 2409 safe_pages_list = lp; 2410 } 2411 /* Mark the page as allocated */ 2412 swsusp_set_page_forbidden(virt_to_page(lp)); 2413 swsusp_set_page_free(virt_to_page(lp)); 2414 nr_pages--; 2415 } 2416 /* Free the reserved safe pages so that chain_alloc() can use them */ 2417 while (sp_list) { 2418 lp = sp_list->next; 2419 free_image_page(sp_list, PG_UNSAFE_CLEAR); 2420 sp_list = lp; 2421 } 2422 return 0; 2423 2424 Free: 2425 swsusp_free(); 2426 return error; 2427 } 2428 2429 /** 2430 * get_buffer - compute the address that snapshot_write_next() should 2431 * set for its caller to write to. 2432 */ 2433 2434 static void *get_buffer(struct memory_bitmap *bm, struct chain_allocator *ca) 2435 { 2436 struct pbe *pbe; 2437 struct page *page; 2438 unsigned long pfn = memory_bm_next_pfn(bm); 2439 2440 if (pfn == BM_END_OF_MAP) 2441 return ERR_PTR(-EFAULT); 2442 2443 page = pfn_to_page(pfn); 2444 if (PageHighMem(page)) 2445 return get_highmem_page_buffer(page, ca); 2446 2447 if (swsusp_page_is_forbidden(page) && swsusp_page_is_free(page)) 2448 /* We have allocated the "original" page frame and we can 2449 * use it directly to store the loaded page. 2450 */ 2451 return page_address(page); 2452 2453 /* The "original" page frame has not been allocated and we have to 2454 * use a "safe" page frame to store the loaded page. 2455 */ 2456 pbe = chain_alloc(ca, sizeof(struct pbe)); 2457 if (!pbe) { 2458 swsusp_free(); 2459 return ERR_PTR(-ENOMEM); 2460 } 2461 pbe->orig_address = page_address(page); 2462 pbe->address = safe_pages_list; 2463 safe_pages_list = safe_pages_list->next; 2464 pbe->next = restore_pblist; 2465 restore_pblist = pbe; 2466 return pbe->address; 2467 } 2468 2469 /** 2470 * snapshot_write_next - used for writing the system memory snapshot. 2471 * 2472 * On the first call to it @handle should point to a zeroed 2473 * snapshot_handle structure. The structure gets updated and a pointer 2474 * to it should be passed to this function every next time. 2475 * 2476 * On success the function returns a positive number. Then, the caller 2477 * is allowed to write up to the returned number of bytes to the memory 2478 * location computed by the data_of() macro. 2479 * 2480 * The function returns 0 to indicate the "end of file" condition, 2481 * and a negative number is returned on error. In such cases the 2482 * structure pointed to by @handle is not updated and should not be used 2483 * any more. 2484 */ 2485 2486 int snapshot_write_next(struct snapshot_handle *handle) 2487 { 2488 static struct chain_allocator ca; 2489 int error = 0; 2490 2491 /* Check if we have already loaded the entire image */ 2492 if (handle->cur > 1 && handle->cur > nr_meta_pages + nr_copy_pages) 2493 return 0; 2494 2495 handle->sync_read = 1; 2496 2497 if (!handle->cur) { 2498 if (!buffer) 2499 /* This makes the buffer be freed by swsusp_free() */ 2500 buffer = get_image_page(GFP_ATOMIC, PG_ANY); 2501 2502 if (!buffer) 2503 return -ENOMEM; 2504 2505 handle->buffer = buffer; 2506 } else if (handle->cur == 1) { 2507 error = load_header(buffer); 2508 if (error) 2509 return error; 2510 2511 error = memory_bm_create(©_bm, GFP_ATOMIC, PG_ANY); 2512 if (error) 2513 return error; 2514 2515 /* Allocate buffer for page keys. */ 2516 error = page_key_alloc(nr_copy_pages); 2517 if (error) 2518 return error; 2519 2520 } else if (handle->cur <= nr_meta_pages + 1) { 2521 error = unpack_orig_pfns(buffer, ©_bm); 2522 if (error) 2523 return error; 2524 2525 if (handle->cur == nr_meta_pages + 1) { 2526 error = prepare_image(&orig_bm, ©_bm); 2527 if (error) 2528 return error; 2529 2530 chain_init(&ca, GFP_ATOMIC, PG_SAFE); 2531 memory_bm_position_reset(&orig_bm); 2532 restore_pblist = NULL; 2533 handle->buffer = get_buffer(&orig_bm, &ca); 2534 handle->sync_read = 0; 2535 if (IS_ERR(handle->buffer)) 2536 return PTR_ERR(handle->buffer); 2537 } 2538 } else { 2539 copy_last_highmem_page(); 2540 /* Restore page key for data page (s390 only). */ 2541 page_key_write(handle->buffer); 2542 handle->buffer = get_buffer(&orig_bm, &ca); 2543 if (IS_ERR(handle->buffer)) 2544 return PTR_ERR(handle->buffer); 2545 if (handle->buffer != buffer) 2546 handle->sync_read = 0; 2547 } 2548 handle->cur++; 2549 return PAGE_SIZE; 2550 } 2551 2552 /** 2553 * snapshot_write_finalize - must be called after the last call to 2554 * snapshot_write_next() in case the last page in the image happens 2555 * to be a highmem page and its contents should be stored in the 2556 * highmem. Additionally, it releases the memory that will not be 2557 * used any more. 2558 */ 2559 2560 void snapshot_write_finalize(struct snapshot_handle *handle) 2561 { 2562 copy_last_highmem_page(); 2563 /* Restore page key for data page (s390 only). */ 2564 page_key_write(handle->buffer); 2565 page_key_free(); 2566 /* Free only if we have loaded the image entirely */ 2567 if (handle->cur > 1 && handle->cur > nr_meta_pages + nr_copy_pages) { 2568 memory_bm_free(&orig_bm, PG_UNSAFE_CLEAR); 2569 free_highmem_data(); 2570 } 2571 } 2572 2573 int snapshot_image_loaded(struct snapshot_handle *handle) 2574 { 2575 return !(!nr_copy_pages || !last_highmem_page_copied() || 2576 handle->cur <= nr_meta_pages + nr_copy_pages); 2577 } 2578 2579 #ifdef CONFIG_HIGHMEM 2580 /* Assumes that @buf is ready and points to a "safe" page */ 2581 static inline void 2582 swap_two_pages_data(struct page *p1, struct page *p2, void *buf) 2583 { 2584 void *kaddr1, *kaddr2; 2585 2586 kaddr1 = kmap_atomic(p1); 2587 kaddr2 = kmap_atomic(p2); 2588 copy_page(buf, kaddr1); 2589 copy_page(kaddr1, kaddr2); 2590 copy_page(kaddr2, buf); 2591 kunmap_atomic(kaddr2); 2592 kunmap_atomic(kaddr1); 2593 } 2594 2595 /** 2596 * restore_highmem - for each highmem page that was allocated before 2597 * the suspend and included in the suspend image, and also has been 2598 * allocated by the "resume" kernel swap its current (ie. "before 2599 * resume") contents with the previous (ie. "before suspend") one. 2600 * 2601 * If the resume eventually fails, we can call this function once 2602 * again and restore the "before resume" highmem state. 2603 */ 2604 2605 int restore_highmem(void) 2606 { 2607 struct highmem_pbe *pbe = highmem_pblist; 2608 void *buf; 2609 2610 if (!pbe) 2611 return 0; 2612 2613 buf = get_image_page(GFP_ATOMIC, PG_SAFE); 2614 if (!buf) 2615 return -ENOMEM; 2616 2617 while (pbe) { 2618 swap_two_pages_data(pbe->copy_page, pbe->orig_page, buf); 2619 pbe = pbe->next; 2620 } 2621 free_image_page(buf, PG_UNSAFE_CLEAR); 2622 return 0; 2623 } 2624 #endif /* CONFIG_HIGHMEM */ 2625