1// SPDX-License-Identifier: GPL-2.0-only
2/*
3 * linux/kernel/power/snapshot.c
4 *
5 * This file provides system snapshot/restore functionality for swsusp.
6 *
7 * Copyright (C) 1998-2005 Pavel Machek <pavel@ucw.cz>
8 * Copyright (C) 2006 Rafael J. Wysocki <rjw@sisk.pl>
9 */
10
11#define pr_fmt(fmt) "PM: hibernation: " fmt
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/memblock.h>
25#include <linux/nmi.h>
26#include <linux/syscalls.h>
27#include <linux/console.h>
28#include <linux/highmem.h>
29#include <linux/list.h>
30#include <linux/slab.h>
31#include <linux/compiler.h>
32#include <linux/ktime.h>
33#include <linux/set_memory.h>
34
35#include <linux/uaccess.h>
36#include <asm/mmu_context.h>
37#include <asm/tlbflush.h>
38#include <asm/io.h>
39
40#include "power.h"
41
42#if defined(CONFIG_STRICT_KERNEL_RWX) && defined(CONFIG_ARCH_HAS_SET_MEMORY)
43static bool hibernate_restore_protection;
44static bool hibernate_restore_protection_active;
45
46void enable_restore_image_protection(void)
47{
48 hibernate_restore_protection = true;
49}
50
51static inline void hibernate_restore_protection_begin(void)
52{
53 hibernate_restore_protection_active = hibernate_restore_protection;
54}
55
56static inline void hibernate_restore_protection_end(void)
57{
58 hibernate_restore_protection_active = false;
59}
60
61static inline int __must_check hibernate_restore_protect_page(void *page_address)
62{
63 if (hibernate_restore_protection_active)
64 return set_memory_ro(addr: (unsigned long)page_address, numpages: 1);
65 return 0;
66}
67
68static inline int hibernate_restore_unprotect_page(void *page_address)
69{
70 if (hibernate_restore_protection_active)
71 return set_memory_rw(addr: (unsigned long)page_address, numpages: 1);
72 return 0;
73}
74#else
75static inline void hibernate_restore_protection_begin(void) {}
76static inline void hibernate_restore_protection_end(void) {}
77static inline int __must_check hibernate_restore_protect_page(void *page_address) {return 0; }
78static inline int hibernate_restore_unprotect_page(void *page_address) {return 0; }
79#endif /* CONFIG_STRICT_KERNEL_RWX && CONFIG_ARCH_HAS_SET_MEMORY */
80
81
82/*
83 * The calls to set_direct_map_*() should not fail because remapping a page
84 * here means that we only update protection bits in an existing PTE.
85 * It is still worth to have a warning here if something changes and this
86 * will no longer be the case.
87 */
88static inline void hibernate_map_page(struct page *page)
89{
90 if (IS_ENABLED(CONFIG_ARCH_HAS_SET_DIRECT_MAP)) {
91 int ret = set_direct_map_default_noflush(page);
92
93 if (ret)
94 pr_warn_once("Failed to remap page\n");
95 } else {
96 debug_pagealloc_map_pages(page, numpages: 1);
97 }
98}
99
100static inline void hibernate_unmap_page(struct page *page)
101{
102 if (IS_ENABLED(CONFIG_ARCH_HAS_SET_DIRECT_MAP)) {
103 unsigned long addr = (unsigned long)page_address(page);
104 int ret = set_direct_map_invalid_noflush(page);
105
106 if (ret)
107 pr_warn_once("Failed to remap page\n");
108
109 flush_tlb_kernel_range(start: addr, end: addr + PAGE_SIZE);
110 } else {
111 debug_pagealloc_unmap_pages(page, numpages: 1);
112 }
113}
114
115static int swsusp_page_is_free(struct page *);
116static void swsusp_set_page_forbidden(struct page *);
117static void swsusp_unset_page_forbidden(struct page *);
118
119/*
120 * Number of bytes to reserve for memory allocations made by device drivers
121 * from their ->freeze() and ->freeze_noirq() callbacks so that they don't
122 * cause image creation to fail (tunable via /sys/power/reserved_size).
123 */
124unsigned long reserved_size;
125
126void __init hibernate_reserved_size_init(void)
127{
128 reserved_size = SPARE_PAGES * PAGE_SIZE;
129}
130
131/*
132 * Preferred image size in bytes (tunable via /sys/power/image_size).
133 * When it is set to N, swsusp will do its best to ensure the image
134 * size will not exceed N bytes, but if that is impossible, it will
135 * try to create the smallest image possible.
136 */
137unsigned long image_size;
138
139void __init hibernate_image_size_init(void)
140{
141 image_size = ((totalram_pages() * 2) / 5) * PAGE_SIZE;
142}
143
144/*
145 * List of PBEs needed for restoring the pages that were allocated before
146 * the suspend and included in the suspend image, but have also been
147 * allocated by the "resume" kernel, so their contents cannot be written
148 * directly to their "original" page frames.
149 */
150struct pbe *restore_pblist;
151
152/* struct linked_page is used to build chains of pages */
153
154#define LINKED_PAGE_DATA_SIZE (PAGE_SIZE - sizeof(void *))
155
156struct linked_page {
157 struct linked_page *next;
158 char data[LINKED_PAGE_DATA_SIZE];
159} __packed;
160
161/*
162 * List of "safe" pages (ie. pages that were not used by the image kernel
163 * before hibernation) that may be used as temporary storage for image kernel
164 * memory contents.
165 */
166static struct linked_page *safe_pages_list;
167
168/* Pointer to an auxiliary buffer (1 page) */
169static void *buffer;
170
171#define PG_ANY 0
172#define PG_SAFE 1
173#define PG_UNSAFE_CLEAR 1
174#define PG_UNSAFE_KEEP 0
175
176static unsigned int allocated_unsafe_pages;
177
178/**
179 * get_image_page - Allocate a page for a hibernation image.
180 * @gfp_mask: GFP mask for the allocation.
181 * @safe_needed: Get pages that were not used before hibernation (restore only)
182 *
183 * During image restoration, for storing the PBE list and the image data, we can
184 * only use memory pages that do not conflict with the pages used before
185 * hibernation. The "unsafe" pages have PageNosaveFree set and we count them
186 * using allocated_unsafe_pages.
187 *
188 * Each allocated image page is marked as PageNosave and PageNosaveFree so that
189 * swsusp_free() can release it.
190 */
191static void *get_image_page(gfp_t gfp_mask, int safe_needed)
192{
193 void *res;
194
195 res = (void *)get_zeroed_page(gfp_mask);
196 if (safe_needed)
197 while (res && swsusp_page_is_free(virt_to_page(res))) {
198 /* The page is unsafe, mark it for swsusp_free() */
199 swsusp_set_page_forbidden(virt_to_page(res));
200 allocated_unsafe_pages++;
201 res = (void *)get_zeroed_page(gfp_mask);
202 }
203 if (res) {
204 swsusp_set_page_forbidden(virt_to_page(res));
205 swsusp_set_page_free(virt_to_page(res));
206 }
207 return res;
208}
209
210static void *__get_safe_page(gfp_t gfp_mask)
211{
212 if (safe_pages_list) {
213 void *ret = safe_pages_list;
214
215 safe_pages_list = safe_pages_list->next;
216 memset(s: ret, c: 0, PAGE_SIZE);
217 return ret;
218 }
219 return get_image_page(gfp_mask, PG_SAFE);
220}
221
222unsigned long get_safe_page(gfp_t gfp_mask)
223{
224 return (unsigned long)__get_safe_page(gfp_mask);
225}
226
227static struct page *alloc_image_page(gfp_t gfp_mask)
228{
229 struct page *page;
230
231 page = alloc_page(gfp_mask);
232 if (page) {
233 swsusp_set_page_forbidden(page);
234 swsusp_set_page_free(page);
235 }
236 return page;
237}
238
239static void recycle_safe_page(void *page_address)
240{
241 struct linked_page *lp = page_address;
242
243 lp->next = safe_pages_list;
244 safe_pages_list = lp;
245}
246
247/**
248 * free_image_page - Free a page allocated for hibernation image.
249 * @addr: Address of the page to free.
250 * @clear_nosave_free: If set, clear the PageNosaveFree bit for the page.
251 *
252 * The page to free should have been allocated by get_image_page() (page flags
253 * set by it are affected).
254 */
255static inline void free_image_page(void *addr, int clear_nosave_free)
256{
257 struct page *page;
258
259 BUG_ON(!virt_addr_valid(addr));
260
261 page = virt_to_page(addr);
262
263 swsusp_unset_page_forbidden(page);
264 if (clear_nosave_free)
265 swsusp_unset_page_free(page);
266
267 __free_page(page);
268}
269
270static inline void free_list_of_pages(struct linked_page *list,
271 int clear_page_nosave)
272{
273 while (list) {
274 struct linked_page *lp = list->next;
275
276 free_image_page(addr: list, clear_nosave_free: clear_page_nosave);
277 list = lp;
278 }
279}
280
281/*
282 * struct chain_allocator is used for allocating small objects out of
283 * a linked list of pages called 'the chain'.
284 *
285 * The chain grows each time when there is no room for a new object in
286 * the current page. The allocated objects cannot be freed individually.
287 * It is only possible to free them all at once, by freeing the entire
288 * chain.
289 *
290 * NOTE: The chain allocator may be inefficient if the allocated objects
291 * are not much smaller than PAGE_SIZE.
292 */
293struct chain_allocator {
294 struct linked_page *chain; /* the chain */
295 unsigned int used_space; /* total size of objects allocated out
296 of the current page */
297 gfp_t gfp_mask; /* mask for allocating pages */
298 int safe_needed; /* if set, only "safe" pages are allocated */
299};
300
301static void chain_init(struct chain_allocator *ca, gfp_t gfp_mask,
302 int safe_needed)
303{
304 ca->chain = NULL;
305 ca->used_space = LINKED_PAGE_DATA_SIZE;
306 ca->gfp_mask = gfp_mask;
307 ca->safe_needed = safe_needed;
308}
309
310static void *chain_alloc(struct chain_allocator *ca, unsigned int size)
311{
312 void *ret;
313
314 if (LINKED_PAGE_DATA_SIZE - ca->used_space < size) {
315 struct linked_page *lp;
316
317 lp = ca->safe_needed ? __get_safe_page(gfp_mask: ca->gfp_mask) :
318 get_image_page(gfp_mask: ca->gfp_mask, PG_ANY);
319 if (!lp)
320 return NULL;
321
322 lp->next = ca->chain;
323 ca->chain = lp;
324 ca->used_space = 0;
325 }
326 ret = ca->chain->data + ca->used_space;
327 ca->used_space += size;
328 return ret;
329}
330
331/*
332 * Data types related to memory bitmaps.
333 *
334 * Memory bitmap is a structure consisting of many linked lists of
335 * objects. The main list's elements are of type struct zone_bitmap
336 * and each of them corresponds to one zone. For each zone bitmap
337 * object there is a list of objects of type struct bm_block that
338 * represent each blocks of bitmap in which information is stored.
339 *
340 * struct memory_bitmap contains a pointer to the main list of zone
341 * bitmap objects, a struct bm_position used for browsing the bitmap,
342 * and a pointer to the list of pages used for allocating all of the
343 * zone bitmap objects and bitmap block objects.
344 *
345 * NOTE: It has to be possible to lay out the bitmap in memory
346 * using only allocations of order 0. Additionally, the bitmap is
347 * designed to work with arbitrary number of zones (this is over the
348 * top for now, but let's avoid making unnecessary assumptions ;-).
349 *
350 * struct zone_bitmap contains a pointer to a list of bitmap block
351 * objects and a pointer to the bitmap block object that has been
352 * most recently used for setting bits. Additionally, it contains the
353 * PFNs that correspond to the start and end of the represented zone.
354 *
355 * struct bm_block contains a pointer to the memory page in which
356 * information is stored (in the form of a block of bitmap)
357 * It also contains the pfns that correspond to the start and end of
358 * the represented memory area.
359 *
360 * The memory bitmap is organized as a radix tree to guarantee fast random
361 * access to the bits. There is one radix tree for each zone (as returned
362 * from create_mem_extents).
363 *
364 * One radix tree is represented by one struct mem_zone_bm_rtree. There are
365 * two linked lists for the nodes of the tree, one for the inner nodes and
366 * one for the leaf nodes. The linked leaf nodes are used for fast linear
367 * access of the memory bitmap.
368 *
369 * The struct rtree_node represents one node of the radix tree.
370 */
371
372#define BM_END_OF_MAP (~0UL)
373
374#define BM_BITS_PER_BLOCK (PAGE_SIZE * BITS_PER_BYTE)
375#define BM_BLOCK_SHIFT (PAGE_SHIFT + 3)
376#define BM_BLOCK_MASK ((1UL << BM_BLOCK_SHIFT) - 1)
377
378/*
379 * struct rtree_node is a wrapper struct to link the nodes
380 * of the rtree together for easy linear iteration over
381 * bits and easy freeing
382 */
383struct rtree_node {
384 struct list_head list;
385 unsigned long *data;
386};
387
388/*
389 * struct mem_zone_bm_rtree represents a bitmap used for one
390 * populated memory zone.
391 */
392struct mem_zone_bm_rtree {
393 struct list_head list; /* Link Zones together */
394 struct list_head nodes; /* Radix Tree inner nodes */
395 struct list_head leaves; /* Radix Tree leaves */
396 unsigned long start_pfn; /* Zone start page frame */
397 unsigned long end_pfn; /* Zone end page frame + 1 */
398 struct rtree_node *rtree; /* Radix Tree Root */
399 int levels; /* Number of Radix Tree Levels */
400 unsigned int blocks; /* Number of Bitmap Blocks */
401};
402
403/* struct bm_position is used for browsing memory bitmaps */
404
405struct bm_position {
406 struct mem_zone_bm_rtree *zone;
407 struct rtree_node *node;
408 unsigned long node_pfn;
409 unsigned long cur_pfn;
410 int node_bit;
411};
412
413struct memory_bitmap {
414 struct list_head zones;
415 struct linked_page *p_list; /* list of pages used to store zone
416 bitmap objects and bitmap block
417 objects */
418 struct bm_position cur; /* most recently used bit position */
419};
420
421/* Functions that operate on memory bitmaps */
422
423#define BM_ENTRIES_PER_LEVEL (PAGE_SIZE / sizeof(unsigned long))
424#if BITS_PER_LONG == 32
425#define BM_RTREE_LEVEL_SHIFT (PAGE_SHIFT - 2)
426#else
427#define BM_RTREE_LEVEL_SHIFT (PAGE_SHIFT - 3)
428#endif
429#define BM_RTREE_LEVEL_MASK ((1UL << BM_RTREE_LEVEL_SHIFT) - 1)
430
431/**
432 * alloc_rtree_node - Allocate a new node and add it to the radix tree.
433 * @gfp_mask: GFP mask for the allocation.
434 * @safe_needed: Get pages not used before hibernation (restore only)
435 * @ca: Pointer to a linked list of pages ("a chain") to allocate from
436 * @list: Radix Tree node to add.
437 *
438 * This function is used to allocate inner nodes as well as the
439 * leave nodes of the radix tree. It also adds the node to the
440 * corresponding linked list passed in by the *list parameter.
441 */
442static struct rtree_node *alloc_rtree_node(gfp_t gfp_mask, int safe_needed,
443 struct chain_allocator *ca,
444 struct list_head *list)
445{
446 struct rtree_node *node;
447
448 node = chain_alloc(ca, size: sizeof(struct rtree_node));
449 if (!node)
450 return NULL;
451
452 node->data = get_image_page(gfp_mask, safe_needed);
453 if (!node->data)
454 return NULL;
455
456 list_add_tail(new: &node->list, head: list);
457
458 return node;
459}
460
461/**
462 * add_rtree_block - Add a new leave node to the radix tree.
463 *
464 * The leave nodes need to be allocated in order to keep the leaves
465 * linked list in order. This is guaranteed by the zone->blocks
466 * counter.
467 */
468static int add_rtree_block(struct mem_zone_bm_rtree *zone, gfp_t gfp_mask,
469 int safe_needed, struct chain_allocator *ca)
470{
471 struct rtree_node *node, *block, **dst;
472 unsigned int levels_needed, block_nr;
473 int i;
474
475 block_nr = zone->blocks;
476 levels_needed = 0;
477
478 /* How many levels do we need for this block nr? */
479 while (block_nr) {
480 levels_needed += 1;
481 block_nr >>= BM_RTREE_LEVEL_SHIFT;
482 }
483
484 /* Make sure the rtree has enough levels */
485 for (i = zone->levels; i < levels_needed; i++) {
486 node = alloc_rtree_node(gfp_mask, safe_needed, ca,
487 list: &zone->nodes);
488 if (!node)
489 return -ENOMEM;
490
491 node->data[0] = (unsigned long)zone->rtree;
492 zone->rtree = node;
493 zone->levels += 1;
494 }
495
496 /* Allocate new block */
497 block = alloc_rtree_node(gfp_mask, safe_needed, ca, list: &zone->leaves);
498 if (!block)
499 return -ENOMEM;
500
501 /* Now walk the rtree to insert the block */
502 node = zone->rtree;
503 dst = &zone->rtree;
504 block_nr = zone->blocks;
505 for (i = zone->levels; i > 0; i--) {
506 int index;
507
508 if (!node) {
509 node = alloc_rtree_node(gfp_mask, safe_needed, ca,
510 list: &zone->nodes);
511 if (!node)
512 return -ENOMEM;
513 *dst = node;
514 }
515
516 index = block_nr >> ((i - 1) * BM_RTREE_LEVEL_SHIFT);
517 index &= BM_RTREE_LEVEL_MASK;
518 dst = (struct rtree_node **)&((*dst)->data[index]);
519 node = *dst;
520 }
521
522 zone->blocks += 1;
523 *dst = block;
524
525 return 0;
526}
527
528static void free_zone_bm_rtree(struct mem_zone_bm_rtree *zone,
529 int clear_nosave_free);
530
531/**
532 * create_zone_bm_rtree - Create a radix tree for one zone.
533 *
534 * Allocated the mem_zone_bm_rtree structure and initializes it.
535 * This function also allocated and builds the radix tree for the
536 * zone.
537 */
538static struct mem_zone_bm_rtree *create_zone_bm_rtree(gfp_t gfp_mask,
539 int safe_needed,
540 struct chain_allocator *ca,
541 unsigned long start,
542 unsigned long end)
543{
544 struct mem_zone_bm_rtree *zone;
545 unsigned int i, nr_blocks;
546 unsigned long pages;
547
548 pages = end - start;
549 zone = chain_alloc(ca, size: sizeof(struct mem_zone_bm_rtree));
550 if (!zone)
551 return NULL;
552
553 INIT_LIST_HEAD(list: &zone->nodes);
554 INIT_LIST_HEAD(list: &zone->leaves);
555 zone->start_pfn = start;
556 zone->end_pfn = end;
557 nr_blocks = DIV_ROUND_UP(pages, BM_BITS_PER_BLOCK);
558
559 for (i = 0; i < nr_blocks; i++) {
560 if (add_rtree_block(zone, gfp_mask, safe_needed, ca)) {
561 free_zone_bm_rtree(zone, PG_UNSAFE_CLEAR);
562 return NULL;
563 }
564 }
565
566 return zone;
567}
568
569/**
570 * free_zone_bm_rtree - Free the memory of the radix tree.
571 *
572 * Free all node pages of the radix tree. The mem_zone_bm_rtree
573 * structure itself is not freed here nor are the rtree_node
574 * structs.
575 */
576static void free_zone_bm_rtree(struct mem_zone_bm_rtree *zone,
577 int clear_nosave_free)
578{
579 struct rtree_node *node;
580
581 list_for_each_entry(node, &zone->nodes, list)
582 free_image_page(addr: node->data, clear_nosave_free);
583
584 list_for_each_entry(node, &zone->leaves, list)
585 free_image_page(addr: node->data, clear_nosave_free);
586}
587
588static void memory_bm_position_reset(struct memory_bitmap *bm)
589{
590 bm->cur.zone = list_entry(bm->zones.next, struct mem_zone_bm_rtree,
591 list);
592 bm->cur.node = list_entry(bm->cur.zone->leaves.next,
593 struct rtree_node, list);
594 bm->cur.node_pfn = 0;
595 bm->cur.cur_pfn = BM_END_OF_MAP;
596 bm->cur.node_bit = 0;
597}
598
599static void memory_bm_free(struct memory_bitmap *bm, int clear_nosave_free);
600
601struct mem_extent {
602 struct list_head hook;
603 unsigned long start;
604 unsigned long end;
605};
606
607/**
608 * free_mem_extents - Free a list of memory extents.
609 * @list: List of extents to free.
610 */
611static void free_mem_extents(struct list_head *list)
612{
613 struct mem_extent *ext, *aux;
614
615 list_for_each_entry_safe(ext, aux, list, hook) {
616 list_del(entry: &ext->hook);
617 kfree(objp: ext);
618 }
619}
620
621/**
622 * create_mem_extents - Create a list of memory extents.
623 * @list: List to put the extents into.
624 * @gfp_mask: Mask to use for memory allocations.
625 *
626 * The extents represent contiguous ranges of PFNs.
627 */
628static int create_mem_extents(struct list_head *list, gfp_t gfp_mask)
629{
630 struct zone *zone;
631
632 INIT_LIST_HEAD(list);
633
634 for_each_populated_zone(zone) {
635 unsigned long zone_start, zone_end;
636 struct mem_extent *ext, *cur, *aux;
637
638 zone_start = zone->zone_start_pfn;
639 zone_end = zone_end_pfn(zone);
640
641 list_for_each_entry(ext, list, hook)
642 if (zone_start <= ext->end)
643 break;
644
645 if (&ext->hook == list || zone_end < ext->start) {
646 /* New extent is necessary */
647 struct mem_extent *new_ext;
648
649 new_ext = kzalloc(sizeof(struct mem_extent), gfp_mask);
650 if (!new_ext) {
651 free_mem_extents(list);
652 return -ENOMEM;
653 }
654 new_ext->start = zone_start;
655 new_ext->end = zone_end;
656 list_add_tail(new: &new_ext->hook, head: &ext->hook);
657 continue;
658 }
659
660 /* Merge this zone's range of PFNs with the existing one */
661 if (zone_start < ext->start)
662 ext->start = zone_start;
663 if (zone_end > ext->end)
664 ext->end = zone_end;
665
666 /* More merging may be possible */
667 cur = ext;
668 list_for_each_entry_safe_continue(cur, aux, list, hook) {
669 if (zone_end < cur->start)
670 break;
671 if (zone_end < cur->end)
672 ext->end = cur->end;
673 list_del(entry: &cur->hook);
674 kfree(objp: cur);
675 }
676 }
677
678 return 0;
679}
680
681/**
682 * memory_bm_create - Allocate memory for a memory bitmap.
683 */
684static int memory_bm_create(struct memory_bitmap *bm, gfp_t gfp_mask,
685 int safe_needed)
686{
687 struct chain_allocator ca;
688 struct list_head mem_extents;
689 struct mem_extent *ext;
690 int error;
691
692 chain_init(ca: &ca, gfp_mask, safe_needed);
693 INIT_LIST_HEAD(list: &bm->zones);
694
695 error = create_mem_extents(list: &mem_extents, gfp_mask);
696 if (error)
697 return error;
698
699 list_for_each_entry(ext, &mem_extents, hook) {
700 struct mem_zone_bm_rtree *zone;
701
702 zone = create_zone_bm_rtree(gfp_mask, safe_needed, ca: &ca,
703 start: ext->start, end: ext->end);
704 if (!zone) {
705 error = -ENOMEM;
706 goto Error;
707 }
708 list_add_tail(new: &zone->list, head: &bm->zones);
709 }
710
711 bm->p_list = ca.chain;
712 memory_bm_position_reset(bm);
713 Exit:
714 free_mem_extents(list: &mem_extents);
715 return error;
716
717 Error:
718 bm->p_list = ca.chain;
719 memory_bm_free(bm, PG_UNSAFE_CLEAR);
720 goto Exit;
721}
722
723/**
724 * memory_bm_free - Free memory occupied by the memory bitmap.
725 * @bm: Memory bitmap.
726 */
727static void memory_bm_free(struct memory_bitmap *bm, int clear_nosave_free)
728{
729 struct mem_zone_bm_rtree *zone;
730
731 list_for_each_entry(zone, &bm->zones, list)
732 free_zone_bm_rtree(zone, clear_nosave_free);
733
734 free_list_of_pages(list: bm->p_list, clear_page_nosave: clear_nosave_free);
735
736 INIT_LIST_HEAD(list: &bm->zones);
737}
738
739/**
740 * memory_bm_find_bit - Find the bit for a given PFN in a memory bitmap.
741 *
742 * Find the bit in memory bitmap @bm that corresponds to the given PFN.
743 * The cur.zone, cur.block and cur.node_pfn members of @bm are updated.
744 *
745 * Walk the radix tree to find the page containing the bit that represents @pfn
746 * and return the position of the bit in @addr and @bit_nr.
747 */
748static int memory_bm_find_bit(struct memory_bitmap *bm, unsigned long pfn,
749 void **addr, unsigned int *bit_nr)
750{
751 struct mem_zone_bm_rtree *curr, *zone;
752 struct rtree_node *node;
753 int i, block_nr;
754
755 zone = bm->cur.zone;
756
757 if (pfn >= zone->start_pfn && pfn < zone->end_pfn)
758 goto zone_found;
759
760 zone = NULL;
761
762 /* Find the right zone */
763 list_for_each_entry(curr, &bm->zones, list) {
764 if (pfn >= curr->start_pfn && pfn < curr->end_pfn) {
765 zone = curr;
766 break;
767 }
768 }
769
770 if (!zone)
771 return -EFAULT;
772
773zone_found:
774 /*
775 * We have found the zone. Now walk the radix tree to find the leaf node
776 * for our PFN.
777 */
778
779 /*
780 * If the zone we wish to scan is the current zone and the
781 * pfn falls into the current node then we do not need to walk
782 * the tree.
783 */
784 node = bm->cur.node;
785 if (zone == bm->cur.zone &&
786 ((pfn - zone->start_pfn) & ~BM_BLOCK_MASK) == bm->cur.node_pfn)
787 goto node_found;
788
789 node = zone->rtree;
790 block_nr = (pfn - zone->start_pfn) >> BM_BLOCK_SHIFT;
791
792 for (i = zone->levels; i > 0; i--) {
793 int index;
794
795 index = block_nr >> ((i - 1) * BM_RTREE_LEVEL_SHIFT);
796 index &= BM_RTREE_LEVEL_MASK;
797 BUG_ON(node->data[index] == 0);
798 node = (struct rtree_node *)node->data[index];
799 }
800
801node_found:
802 /* Update last position */
803 bm->cur.zone = zone;
804 bm->cur.node = node;
805 bm->cur.node_pfn = (pfn - zone->start_pfn) & ~BM_BLOCK_MASK;
806 bm->cur.cur_pfn = pfn;
807
808 /* Set return values */
809 *addr = node->data;
810 *bit_nr = (pfn - zone->start_pfn) & BM_BLOCK_MASK;
811
812 return 0;
813}
814
815static void memory_bm_set_bit(struct memory_bitmap *bm, unsigned long pfn)
816{
817 void *addr;
818 unsigned int bit;
819 int error;
820
821 error = memory_bm_find_bit(bm, pfn, addr: &addr, bit_nr: &bit);
822 BUG_ON(error);
823 set_bit(nr: bit, addr);
824}
825
826static int mem_bm_set_bit_check(struct memory_bitmap *bm, unsigned long pfn)
827{
828 void *addr;
829 unsigned int bit;
830 int error;
831
832 error = memory_bm_find_bit(bm, pfn, addr: &addr, bit_nr: &bit);
833 if (!error)
834 set_bit(nr: bit, addr);
835
836 return error;
837}
838
839static void memory_bm_clear_bit(struct memory_bitmap *bm, unsigned long pfn)
840{
841 void *addr;
842 unsigned int bit;
843 int error;
844
845 error = memory_bm_find_bit(bm, pfn, addr: &addr, bit_nr: &bit);
846 BUG_ON(error);
847 clear_bit(nr: bit, addr);
848}
849
850static void memory_bm_clear_current(struct memory_bitmap *bm)
851{
852 int bit;
853
854 bit = max(bm->cur.node_bit - 1, 0);
855 clear_bit(nr: bit, addr: bm->cur.node->data);
856}
857
858static unsigned long memory_bm_get_current(struct memory_bitmap *bm)
859{
860 return bm->cur.cur_pfn;
861}
862
863static int memory_bm_test_bit(struct memory_bitmap *bm, unsigned long pfn)
864{
865 void *addr;
866 unsigned int bit;
867 int error;
868
869 error = memory_bm_find_bit(bm, pfn, addr: &addr, bit_nr: &bit);
870 BUG_ON(error);
871 return test_bit(bit, addr);
872}
873
874static bool memory_bm_pfn_present(struct memory_bitmap *bm, unsigned long pfn)
875{
876 void *addr;
877 unsigned int bit;
878
879 return !memory_bm_find_bit(bm, pfn, addr: &addr, bit_nr: &bit);
880}
881
882/*
883 * rtree_next_node - Jump to the next leaf node.
884 *
885 * Set the position to the beginning of the next node in the
886 * memory bitmap. This is either the next node in the current
887 * zone's radix tree or the first node in the radix tree of the
888 * next zone.
889 *
890 * Return true if there is a next node, false otherwise.
891 */
892static bool rtree_next_node(struct memory_bitmap *bm)
893{
894 if (!list_is_last(list: &bm->cur.node->list, head: &bm->cur.zone->leaves)) {
895 bm->cur.node = list_entry(bm->cur.node->list.next,
896 struct rtree_node, list);
897 bm->cur.node_pfn += BM_BITS_PER_BLOCK;
898 bm->cur.node_bit = 0;
899 touch_softlockup_watchdog();
900 return true;
901 }
902
903 /* No more nodes, goto next zone */
904 if (!list_is_last(list: &bm->cur.zone->list, head: &bm->zones)) {
905 bm->cur.zone = list_entry(bm->cur.zone->list.next,
906 struct mem_zone_bm_rtree, list);
907 bm->cur.node = list_entry(bm->cur.zone->leaves.next,
908 struct rtree_node, list);
909 bm->cur.node_pfn = 0;
910 bm->cur.node_bit = 0;
911 return true;
912 }
913
914 /* No more zones */
915 return false;
916}
917
918/**
919 * memory_bm_next_pfn - Find the next set bit in a memory bitmap.
920 * @bm: Memory bitmap.
921 *
922 * Starting from the last returned position this function searches for the next
923 * set bit in @bm and returns the PFN represented by it. If no more bits are
924 * set, BM_END_OF_MAP is returned.
925 *
926 * It is required to run memory_bm_position_reset() before the first call to
927 * this function for the given memory bitmap.
928 */
929static unsigned long memory_bm_next_pfn(struct memory_bitmap *bm)
930{
931 unsigned long bits, pfn, pages;
932 int bit;
933
934 do {
935 pages = bm->cur.zone->end_pfn - bm->cur.zone->start_pfn;
936 bits = min(pages - bm->cur.node_pfn, BM_BITS_PER_BLOCK);
937 bit = find_next_bit(addr: bm->cur.node->data, size: bits,
938 offset: bm->cur.node_bit);
939 if (bit < bits) {
940 pfn = bm->cur.zone->start_pfn + bm->cur.node_pfn + bit;
941 bm->cur.node_bit = bit + 1;
942 bm->cur.cur_pfn = pfn;
943 return pfn;
944 }
945 } while (rtree_next_node(bm));
946
947 bm->cur.cur_pfn = BM_END_OF_MAP;
948 return BM_END_OF_MAP;
949}
950
951/*
952 * This structure represents a range of page frames the contents of which
953 * should not be saved during hibernation.
954 */
955struct nosave_region {
956 struct list_head list;
957 unsigned long start_pfn;
958 unsigned long end_pfn;
959};
960
961static LIST_HEAD(nosave_regions);
962
963static void recycle_zone_bm_rtree(struct mem_zone_bm_rtree *zone)
964{
965 struct rtree_node *node;
966
967 list_for_each_entry(node, &zone->nodes, list)
968 recycle_safe_page(page_address: node->data);
969
970 list_for_each_entry(node, &zone->leaves, list)
971 recycle_safe_page(page_address: node->data);
972}
973
974static void memory_bm_recycle(struct memory_bitmap *bm)
975{
976 struct mem_zone_bm_rtree *zone;
977 struct linked_page *p_list;
978
979 list_for_each_entry(zone, &bm->zones, list)
980 recycle_zone_bm_rtree(zone);
981
982 p_list = bm->p_list;
983 while (p_list) {
984 struct linked_page *lp = p_list;
985
986 p_list = lp->next;
987 recycle_safe_page(page_address: lp);
988 }
989}
990
991/**
992 * register_nosave_region - Register a region of unsaveable memory.
993 *
994 * Register a range of page frames the contents of which should not be saved
995 * during hibernation (to be used in the early initialization code).
996 */
997void __init register_nosave_region(unsigned long start_pfn, unsigned long end_pfn)
998{
999 struct nosave_region *region;
1000
1001 if (start_pfn >= end_pfn)
1002 return;
1003
1004 if (!list_empty(head: &nosave_regions)) {
1005 /* Try to extend the previous region (they should be sorted) */
1006 region = list_entry(nosave_regions.prev,
1007 struct nosave_region, list);
1008 if (region->end_pfn == start_pfn) {
1009 region->end_pfn = end_pfn;
1010 goto Report;
1011 }
1012 }
1013 /* This allocation cannot fail */
1014 region = memblock_alloc_or_panic(sizeof(struct nosave_region),
1015 SMP_CACHE_BYTES);
1016 region->start_pfn = start_pfn;
1017 region->end_pfn = end_pfn;
1018 list_add_tail(new: &region->list, head: &nosave_regions);
1019 Report:
1020 pr_info("Registered nosave memory: [mem %#010llx-%#010llx]\n",
1021 (unsigned long long) start_pfn << PAGE_SHIFT,
1022 ((unsigned long long) end_pfn << PAGE_SHIFT) - 1);
1023}
1024
1025/*
1026 * Set bits in this map correspond to the page frames the contents of which
1027 * should not be saved during the suspend.
1028 */
1029static struct memory_bitmap *forbidden_pages_map;
1030
1031/* Set bits in this map correspond to free page frames. */
1032static struct memory_bitmap *free_pages_map;
1033
1034/*
1035 * Each page frame allocated for creating the image is marked by setting the
1036 * corresponding bits in forbidden_pages_map and free_pages_map simultaneously
1037 */
1038
1039void swsusp_set_page_free(struct page *page)
1040{
1041 if (free_pages_map)
1042 memory_bm_set_bit(bm: free_pages_map, page_to_pfn(page));
1043}
1044
1045static int swsusp_page_is_free(struct page *page)
1046{
1047 return free_pages_map ?
1048 memory_bm_test_bit(bm: free_pages_map, page_to_pfn(page)) : 0;
1049}
1050
1051void swsusp_unset_page_free(struct page *page)
1052{
1053 if (free_pages_map)
1054 memory_bm_clear_bit(bm: free_pages_map, page_to_pfn(page));
1055}
1056
1057static void swsusp_set_page_forbidden(struct page *page)
1058{
1059 if (forbidden_pages_map)
1060 memory_bm_set_bit(bm: forbidden_pages_map, page_to_pfn(page));
1061}
1062
1063int swsusp_page_is_forbidden(struct page *page)
1064{
1065 return forbidden_pages_map ?
1066 memory_bm_test_bit(bm: forbidden_pages_map, page_to_pfn(page)) : 0;
1067}
1068
1069static void swsusp_unset_page_forbidden(struct page *page)
1070{
1071 if (forbidden_pages_map)
1072 memory_bm_clear_bit(bm: forbidden_pages_map, page_to_pfn(page));
1073}
1074
1075/**
1076 * mark_nosave_pages - Mark pages that should not be saved.
1077 * @bm: Memory bitmap.
1078 *
1079 * Set the bits in @bm that correspond to the page frames the contents of which
1080 * should not be saved.
1081 */
1082static void mark_nosave_pages(struct memory_bitmap *bm)
1083{
1084 struct nosave_region *region;
1085
1086 if (list_empty(head: &nosave_regions))
1087 return;
1088
1089 list_for_each_entry(region, &nosave_regions, list) {
1090 unsigned long pfn;
1091
1092 pr_debug("Marking nosave pages: [mem %#010llx-%#010llx]\n",
1093 (unsigned long long) region->start_pfn << PAGE_SHIFT,
1094 ((unsigned long long) region->end_pfn << PAGE_SHIFT)
1095 - 1);
1096
1097 for_each_valid_pfn(pfn, region->start_pfn, region->end_pfn) {
1098 /*
1099 * It is safe to ignore the result of
1100 * mem_bm_set_bit_check() here, since we won't
1101 * touch the PFNs for which the error is
1102 * returned anyway.
1103 */
1104 mem_bm_set_bit_check(bm, pfn);
1105 }
1106 }
1107}
1108
1109/**
1110 * create_basic_memory_bitmaps - Create bitmaps to hold basic page information.
1111 *
1112 * Create bitmaps needed for marking page frames that should not be saved and
1113 * free page frames. The forbidden_pages_map and free_pages_map pointers are
1114 * only modified if everything goes well, because we don't want the bits to be
1115 * touched before both bitmaps are set up.
1116 */
1117int create_basic_memory_bitmaps(void)
1118{
1119 struct memory_bitmap *bm1, *bm2;
1120 int error;
1121
1122 if (forbidden_pages_map && free_pages_map)
1123 return 0;
1124 else
1125 BUG_ON(forbidden_pages_map || free_pages_map);
1126
1127 bm1 = kzalloc(sizeof(struct memory_bitmap), GFP_KERNEL);
1128 if (!bm1)
1129 return -ENOMEM;
1130
1131 error = memory_bm_create(bm: bm1, GFP_KERNEL, PG_ANY);
1132 if (error)
1133 goto Free_first_object;
1134
1135 bm2 = kzalloc(sizeof(struct memory_bitmap), GFP_KERNEL);
1136 if (!bm2)
1137 goto Free_first_bitmap;
1138
1139 error = memory_bm_create(bm: bm2, GFP_KERNEL, PG_ANY);
1140 if (error)
1141 goto Free_second_object;
1142
1143 forbidden_pages_map = bm1;
1144 free_pages_map = bm2;
1145 mark_nosave_pages(bm: forbidden_pages_map);
1146
1147 pr_debug("Basic memory bitmaps created\n");
1148
1149 return 0;
1150
1151 Free_second_object:
1152 kfree(objp: bm2);
1153 Free_first_bitmap:
1154 memory_bm_free(bm: bm1, PG_UNSAFE_CLEAR);
1155 Free_first_object:
1156 kfree(objp: bm1);
1157 return -ENOMEM;
1158}
1159
1160/**
1161 * free_basic_memory_bitmaps - Free memory bitmaps holding basic information.
1162 *
1163 * Free memory bitmaps allocated by create_basic_memory_bitmaps(). The
1164 * auxiliary pointers are necessary so that the bitmaps themselves are not
1165 * referred to while they are being freed.
1166 */
1167void free_basic_memory_bitmaps(void)
1168{
1169 struct memory_bitmap *bm1, *bm2;
1170
1171 if (WARN_ON(!(forbidden_pages_map && free_pages_map)))
1172 return;
1173
1174 bm1 = forbidden_pages_map;
1175 bm2 = free_pages_map;
1176 forbidden_pages_map = NULL;
1177 free_pages_map = NULL;
1178 memory_bm_free(bm: bm1, PG_UNSAFE_CLEAR);
1179 kfree(objp: bm1);
1180 memory_bm_free(bm: bm2, PG_UNSAFE_CLEAR);
1181 kfree(objp: bm2);
1182
1183 pr_debug("Basic memory bitmaps freed\n");
1184}
1185
1186static void clear_or_poison_free_page(struct page *page)
1187{
1188 if (page_poisoning_enabled_static())
1189 __kernel_poison_pages(page, nunmpages: 1);
1190 else if (want_init_on_free())
1191 clear_highpage(page);
1192}
1193
1194void clear_or_poison_free_pages(void)
1195{
1196 struct memory_bitmap *bm = free_pages_map;
1197 unsigned long pfn;
1198
1199 if (WARN_ON(!(free_pages_map)))
1200 return;
1201
1202 if (page_poisoning_enabled() || want_init_on_free()) {
1203 memory_bm_position_reset(bm);
1204 pfn = memory_bm_next_pfn(bm);
1205 while (pfn != BM_END_OF_MAP) {
1206 if (pfn_valid(pfn))
1207 clear_or_poison_free_page(pfn_to_page(pfn));
1208
1209 pfn = memory_bm_next_pfn(bm);
1210 }
1211 memory_bm_position_reset(bm);
1212 pr_info("free pages cleared after restore\n");
1213 }
1214}
1215
1216/**
1217 * snapshot_additional_pages - Estimate the number of extra pages needed.
1218 * @zone: Memory zone to carry out the computation for.
1219 *
1220 * Estimate the number of additional pages needed for setting up a hibernation
1221 * image data structures for @zone (usually, the returned value is greater than
1222 * the exact number).
1223 */
1224unsigned int snapshot_additional_pages(struct zone *zone)
1225{
1226 unsigned int rtree, nodes;
1227
1228 rtree = nodes = DIV_ROUND_UP(zone->spanned_pages, BM_BITS_PER_BLOCK);
1229 rtree += DIV_ROUND_UP(rtree * sizeof(struct rtree_node),
1230 LINKED_PAGE_DATA_SIZE);
1231 while (nodes > 1) {
1232 nodes = DIV_ROUND_UP(nodes, BM_ENTRIES_PER_LEVEL);
1233 rtree += nodes;
1234 }
1235
1236 return 2 * rtree;
1237}
1238
1239/*
1240 * Touch the watchdog for every WD_PAGE_COUNT pages.
1241 */
1242#define WD_PAGE_COUNT (128*1024)
1243
1244static void mark_free_pages(struct zone *zone)
1245{
1246 unsigned long pfn, max_zone_pfn, page_count = WD_PAGE_COUNT;
1247 unsigned long flags;
1248 unsigned int order, t;
1249 struct page *page;
1250
1251 if (zone_is_empty(zone))
1252 return;
1253
1254 spin_lock_irqsave(&zone->lock, flags);
1255
1256 max_zone_pfn = zone_end_pfn(zone);
1257 for_each_valid_pfn(pfn, zone->zone_start_pfn, max_zone_pfn) {
1258 page = pfn_to_page(pfn);
1259
1260 if (!--page_count) {
1261 touch_nmi_watchdog();
1262 page_count = WD_PAGE_COUNT;
1263 }
1264
1265 if (page_zone(page) != zone)
1266 continue;
1267
1268 if (!swsusp_page_is_forbidden(page))
1269 swsusp_unset_page_free(page);
1270 }
1271
1272 for_each_migratetype_order(order, t) {
1273 list_for_each_entry(page,
1274 &zone->free_area[order].free_list[t], buddy_list) {
1275 unsigned long i;
1276
1277 pfn = page_to_pfn(page);
1278 for (i = 0; i < (1UL << order); i++) {
1279 if (!--page_count) {
1280 touch_nmi_watchdog();
1281 page_count = WD_PAGE_COUNT;
1282 }
1283 swsusp_set_page_free(pfn_to_page(pfn + i));
1284 }
1285 }
1286 }
1287 spin_unlock_irqrestore(lock: &zone->lock, flags);
1288}
1289
1290#ifdef CONFIG_HIGHMEM
1291/**
1292 * count_free_highmem_pages - Compute the total number of free highmem pages.
1293 *
1294 * The returned number is system-wide.
1295 */
1296static unsigned int count_free_highmem_pages(void)
1297{
1298 struct zone *zone;
1299 unsigned int cnt = 0;
1300
1301 for_each_populated_zone(zone)
1302 if (is_highmem(zone))
1303 cnt += zone_page_state(zone, NR_FREE_PAGES);
1304
1305 return cnt;
1306}
1307
1308/**
1309 * saveable_highmem_page - Check if a highmem page is saveable.
1310 *
1311 * Determine whether a highmem page should be included in a hibernation image.
1312 *
1313 * We should save the page if it isn't Nosave or NosaveFree, or Reserved,
1314 * and it isn't part of a free chunk of pages.
1315 */
1316static struct page *saveable_highmem_page(struct zone *zone, unsigned long pfn)
1317{
1318 struct page *page;
1319
1320 if (!pfn_valid(pfn))
1321 return NULL;
1322
1323 page = pfn_to_online_page(pfn);
1324 if (!page || page_zone(page) != zone)
1325 return NULL;
1326
1327 BUG_ON(!PageHighMem(page));
1328
1329 if (swsusp_page_is_forbidden(page) || swsusp_page_is_free(page))
1330 return NULL;
1331
1332 if (PageReserved(page) || PageOffline(page))
1333 return NULL;
1334
1335 if (page_is_guard(page))
1336 return NULL;
1337
1338 return page;
1339}
1340
1341/**
1342 * count_highmem_pages - Compute the total number of saveable highmem pages.
1343 */
1344static unsigned int count_highmem_pages(void)
1345{
1346 struct zone *zone;
1347 unsigned int n = 0;
1348
1349 for_each_populated_zone(zone) {
1350 unsigned long pfn, max_zone_pfn;
1351
1352 if (!is_highmem(zone))
1353 continue;
1354
1355 mark_free_pages(zone);
1356 max_zone_pfn = zone_end_pfn(zone);
1357 for (pfn = zone->zone_start_pfn; pfn < max_zone_pfn; pfn++)
1358 if (saveable_highmem_page(zone, pfn))
1359 n++;
1360 }
1361 return n;
1362}
1363#endif /* CONFIG_HIGHMEM */
1364
1365/**
1366 * saveable_page - Check if the given page is saveable.
1367 *
1368 * Determine whether a non-highmem page should be included in a hibernation
1369 * image.
1370 *
1371 * We should save the page if it isn't Nosave, and is not in the range
1372 * of pages statically defined as 'unsaveable', and it isn't part of
1373 * a free chunk of pages.
1374 */
1375static struct page *saveable_page(struct zone *zone, unsigned long pfn)
1376{
1377 struct page *page;
1378
1379 if (!pfn_valid(pfn))
1380 return NULL;
1381
1382 page = pfn_to_online_page(pfn);
1383 if (!page || page_zone(page) != zone)
1384 return NULL;
1385
1386 BUG_ON(PageHighMem(page));
1387
1388 if (swsusp_page_is_forbidden(page) || swsusp_page_is_free(page))
1389 return NULL;
1390
1391 if (PageOffline(page))
1392 return NULL;
1393
1394 if (PageReserved(page)
1395 && (!kernel_page_present(page) || pfn_is_nosave(pfn)))
1396 return NULL;
1397
1398 if (page_is_guard(page))
1399 return NULL;
1400
1401 return page;
1402}
1403
1404/**
1405 * count_data_pages - Compute the total number of saveable non-highmem pages.
1406 */
1407static unsigned int count_data_pages(void)
1408{
1409 struct zone *zone;
1410 unsigned long pfn, max_zone_pfn;
1411 unsigned int n = 0;
1412
1413 for_each_populated_zone(zone) {
1414 if (is_highmem(zone))
1415 continue;
1416
1417 mark_free_pages(zone);
1418 max_zone_pfn = zone_end_pfn(zone);
1419 for (pfn = zone->zone_start_pfn; pfn < max_zone_pfn; pfn++)
1420 if (saveable_page(zone, pfn))
1421 n++;
1422 }
1423 return n;
1424}
1425
1426/*
1427 * This is needed, because copy_page and memcpy are not usable for copying
1428 * task structs. Returns true if the page was filled with only zeros,
1429 * otherwise false.
1430 */
1431static inline bool do_copy_page(long *dst, long *src)
1432{
1433 long z = 0;
1434 int n;
1435
1436 for (n = PAGE_SIZE / sizeof(long); n; n--) {
1437 z |= *src;
1438 *dst++ = *src++;
1439 }
1440 return !z;
1441}
1442
1443/**
1444 * safe_copy_page - Copy a page in a safe way.
1445 *
1446 * Check if the page we are going to copy is marked as present in the kernel
1447 * page tables. This always is the case if CONFIG_DEBUG_PAGEALLOC or
1448 * CONFIG_ARCH_HAS_SET_DIRECT_MAP is not set. In that case kernel_page_present()
1449 * always returns 'true'. Returns true if the page was entirely composed of
1450 * zeros, otherwise it will return false.
1451 */
1452static bool safe_copy_page(void *dst, struct page *s_page)
1453{
1454 bool zeros_only;
1455
1456 if (kernel_page_present(page: s_page)) {
1457 zeros_only = do_copy_page(dst, page_address(s_page));
1458 } else {
1459 hibernate_map_page(page: s_page);
1460 zeros_only = do_copy_page(dst, page_address(s_page));
1461 hibernate_unmap_page(page: s_page);
1462 }
1463 return zeros_only;
1464}
1465
1466#ifdef CONFIG_HIGHMEM
1467static inline struct page *page_is_saveable(struct zone *zone, unsigned long pfn)
1468{
1469 return is_highmem(zone) ?
1470 saveable_highmem_page(zone, pfn) : saveable_page(zone, pfn);
1471}
1472
1473static bool copy_data_page(unsigned long dst_pfn, unsigned long src_pfn)
1474{
1475 struct page *s_page, *d_page;
1476 void *src, *dst;
1477 bool zeros_only;
1478
1479 s_page = pfn_to_page(src_pfn);
1480 d_page = pfn_to_page(dst_pfn);
1481 if (PageHighMem(s_page)) {
1482 src = kmap_local_page(s_page);
1483 dst = kmap_local_page(d_page);
1484 zeros_only = do_copy_page(dst, src);
1485 kunmap_local(dst);
1486 kunmap_local(src);
1487 } else {
1488 if (PageHighMem(d_page)) {
1489 /*
1490 * The page pointed to by src may contain some kernel
1491 * data modified by kmap_atomic()
1492 */
1493 zeros_only = safe_copy_page(buffer, s_page);
1494 dst = kmap_local_page(d_page);
1495 copy_page(dst, buffer);
1496 kunmap_local(dst);
1497 } else {
1498 zeros_only = safe_copy_page(page_address(d_page), s_page);
1499 }
1500 }
1501 return zeros_only;
1502}
1503#else
1504#define page_is_saveable(zone, pfn) saveable_page(zone, pfn)
1505
1506static inline int copy_data_page(unsigned long dst_pfn, unsigned long src_pfn)
1507{
1508 return safe_copy_page(page_address(pfn_to_page(dst_pfn)),
1509 pfn_to_page(src_pfn));
1510}
1511#endif /* CONFIG_HIGHMEM */
1512
1513/*
1514 * Copy data pages will copy all pages into pages pulled from the copy_bm.
1515 * If a page was entirely filled with zeros it will be marked in the zero_bm.
1516 *
1517 * Returns the number of pages copied.
1518 */
1519static unsigned long copy_data_pages(struct memory_bitmap *copy_bm,
1520 struct memory_bitmap *orig_bm,
1521 struct memory_bitmap *zero_bm)
1522{
1523 unsigned long copied_pages = 0;
1524 struct zone *zone;
1525 unsigned long pfn, copy_pfn;
1526
1527 for_each_populated_zone(zone) {
1528 unsigned long max_zone_pfn;
1529
1530 mark_free_pages(zone);
1531 max_zone_pfn = zone_end_pfn(zone);
1532 for (pfn = zone->zone_start_pfn; pfn < max_zone_pfn; pfn++)
1533 if (page_is_saveable(zone, pfn))
1534 memory_bm_set_bit(bm: orig_bm, pfn);
1535 }
1536 memory_bm_position_reset(bm: orig_bm);
1537 memory_bm_position_reset(bm: copy_bm);
1538 copy_pfn = memory_bm_next_pfn(bm: copy_bm);
1539 for (;;) {
1540 pfn = memory_bm_next_pfn(bm: orig_bm);
1541 if (unlikely(pfn == BM_END_OF_MAP))
1542 break;
1543 if (copy_data_page(dst_pfn: copy_pfn, src_pfn: pfn)) {
1544 memory_bm_set_bit(bm: zero_bm, pfn);
1545 /* Use this copy_pfn for a page that is not full of zeros */
1546 continue;
1547 }
1548 copied_pages++;
1549 copy_pfn = memory_bm_next_pfn(bm: copy_bm);
1550 }
1551 return copied_pages;
1552}
1553
1554/* Total number of image pages */
1555static unsigned int nr_copy_pages;
1556/* Number of pages needed for saving the original pfns of the image pages */
1557static unsigned int nr_meta_pages;
1558/* Number of zero pages */
1559static unsigned int nr_zero_pages;
1560
1561/*
1562 * Numbers of normal and highmem page frames allocated for hibernation image
1563 * before suspending devices.
1564 */
1565static unsigned int alloc_normal, alloc_highmem;
1566/*
1567 * Memory bitmap used for marking saveable pages (during hibernation) or
1568 * hibernation image pages (during restore)
1569 */
1570static struct memory_bitmap orig_bm;
1571/*
1572 * Memory bitmap used during hibernation for marking allocated page frames that
1573 * will contain copies of saveable pages. During restore it is initially used
1574 * for marking hibernation image pages, but then the set bits from it are
1575 * duplicated in @orig_bm and it is released. On highmem systems it is next
1576 * used for marking "safe" highmem pages, but it has to be reinitialized for
1577 * this purpose.
1578 */
1579static struct memory_bitmap copy_bm;
1580
1581/* Memory bitmap which tracks which saveable pages were zero filled. */
1582static struct memory_bitmap zero_bm;
1583
1584/**
1585 * swsusp_free - Free pages allocated for hibernation image.
1586 *
1587 * Image pages are allocated before snapshot creation, so they need to be
1588 * released after resume.
1589 */
1590void swsusp_free(void)
1591{
1592 unsigned long fb_pfn, fr_pfn;
1593
1594 if (!forbidden_pages_map || !free_pages_map)
1595 goto out;
1596
1597 memory_bm_position_reset(bm: forbidden_pages_map);
1598 memory_bm_position_reset(bm: free_pages_map);
1599
1600loop:
1601 fr_pfn = memory_bm_next_pfn(bm: free_pages_map);
1602 fb_pfn = memory_bm_next_pfn(bm: forbidden_pages_map);
1603
1604 /*
1605 * Find the next bit set in both bitmaps. This is guaranteed to
1606 * terminate when fb_pfn == fr_pfn == BM_END_OF_MAP.
1607 */
1608 do {
1609 if (fb_pfn < fr_pfn)
1610 fb_pfn = memory_bm_next_pfn(bm: forbidden_pages_map);
1611 if (fr_pfn < fb_pfn)
1612 fr_pfn = memory_bm_next_pfn(bm: free_pages_map);
1613 } while (fb_pfn != fr_pfn);
1614
1615 if (fr_pfn != BM_END_OF_MAP && pfn_valid(pfn: fr_pfn)) {
1616 struct page *page = pfn_to_page(fr_pfn);
1617
1618 memory_bm_clear_current(bm: forbidden_pages_map);
1619 memory_bm_clear_current(bm: free_pages_map);
1620 hibernate_restore_unprotect_page(page_address(page));
1621 __free_page(page);
1622 goto loop;
1623 }
1624
1625out:
1626 nr_copy_pages = 0;
1627 nr_meta_pages = 0;
1628 nr_zero_pages = 0;
1629 restore_pblist = NULL;
1630 buffer = NULL;
1631 alloc_normal = 0;
1632 alloc_highmem = 0;
1633 hibernate_restore_protection_end();
1634}
1635
1636/* Helper functions used for the shrinking of memory. */
1637
1638#define GFP_IMAGE (GFP_KERNEL | __GFP_NOWARN)
1639
1640/**
1641 * preallocate_image_pages - Allocate a number of pages for hibernation image.
1642 * @nr_pages: Number of page frames to allocate.
1643 * @mask: GFP flags to use for the allocation.
1644 *
1645 * Return value: Number of page frames actually allocated
1646 */
1647static unsigned long preallocate_image_pages(unsigned long nr_pages, gfp_t mask)
1648{
1649 unsigned long nr_alloc = 0;
1650
1651 while (nr_pages > 0) {
1652 struct page *page;
1653
1654 page = alloc_image_page(gfp_mask: mask);
1655 if (!page)
1656 break;
1657 memory_bm_set_bit(bm: &copy_bm, page_to_pfn(page));
1658 if (PageHighMem(page))
1659 alloc_highmem++;
1660 else
1661 alloc_normal++;
1662 nr_pages--;
1663 nr_alloc++;
1664 }
1665
1666 return nr_alloc;
1667}
1668
1669static unsigned long preallocate_image_memory(unsigned long nr_pages,
1670 unsigned long avail_normal)
1671{
1672 unsigned long alloc;
1673
1674 if (avail_normal <= alloc_normal)
1675 return 0;
1676
1677 alloc = avail_normal - alloc_normal;
1678 if (nr_pages < alloc)
1679 alloc = nr_pages;
1680
1681 return preallocate_image_pages(nr_pages: alloc, GFP_IMAGE);
1682}
1683
1684#ifdef CONFIG_HIGHMEM
1685static unsigned long preallocate_image_highmem(unsigned long nr_pages)
1686{
1687 return preallocate_image_pages(nr_pages, GFP_IMAGE | __GFP_HIGHMEM);
1688}
1689
1690/**
1691 * __fraction - Compute (an approximation of) x * (multiplier / base).
1692 */
1693static unsigned long __fraction(u64 x, u64 multiplier, u64 base)
1694{
1695 return div64_u64(x * multiplier, base);
1696}
1697
1698static unsigned long preallocate_highmem_fraction(unsigned long nr_pages,
1699 unsigned long highmem,
1700 unsigned long total)
1701{
1702 unsigned long alloc = __fraction(nr_pages, highmem, total);
1703
1704 return preallocate_image_pages(alloc, GFP_IMAGE | __GFP_HIGHMEM);
1705}
1706#else /* CONFIG_HIGHMEM */
1707static inline unsigned long preallocate_image_highmem(unsigned long nr_pages)
1708{
1709 return 0;
1710}
1711
1712static inline unsigned long preallocate_highmem_fraction(unsigned long nr_pages,
1713 unsigned long highmem,
1714 unsigned long total)
1715{
1716 return 0;
1717}
1718#endif /* CONFIG_HIGHMEM */
1719
1720/**
1721 * free_unnecessary_pages - Release preallocated pages not needed for the image.
1722 */
1723static unsigned long free_unnecessary_pages(void)
1724{
1725 unsigned long save, to_free_normal, to_free_highmem, free;
1726
1727 save = count_data_pages();
1728 if (alloc_normal >= save) {
1729 to_free_normal = alloc_normal - save;
1730 save = 0;
1731 } else {
1732 to_free_normal = 0;
1733 save -= alloc_normal;
1734 }
1735 save += count_highmem_pages();
1736 if (alloc_highmem >= save) {
1737 to_free_highmem = alloc_highmem - save;
1738 } else {
1739 to_free_highmem = 0;
1740 save -= alloc_highmem;
1741 if (to_free_normal > save)
1742 to_free_normal -= save;
1743 else
1744 to_free_normal = 0;
1745 }
1746 free = to_free_normal + to_free_highmem;
1747
1748 memory_bm_position_reset(bm: &copy_bm);
1749
1750 while (to_free_normal > 0 || to_free_highmem > 0) {
1751 unsigned long pfn = memory_bm_next_pfn(bm: &copy_bm);
1752 struct page *page = pfn_to_page(pfn);
1753
1754 if (PageHighMem(page)) {
1755 if (!to_free_highmem)
1756 continue;
1757 to_free_highmem--;
1758 alloc_highmem--;
1759 } else {
1760 if (!to_free_normal)
1761 continue;
1762 to_free_normal--;
1763 alloc_normal--;
1764 }
1765 memory_bm_clear_bit(bm: &copy_bm, pfn);
1766 swsusp_unset_page_forbidden(page);
1767 swsusp_unset_page_free(page);
1768 __free_page(page);
1769 }
1770
1771 return free;
1772}
1773
1774/**
1775 * minimum_image_size - Estimate the minimum acceptable size of an image.
1776 * @saveable: Number of saveable pages in the system.
1777 *
1778 * We want to avoid attempting to free too much memory too hard, so estimate the
1779 * minimum acceptable size of a hibernation image to use as the lower limit for
1780 * preallocating memory.
1781 *
1782 * We assume that the minimum image size should be proportional to
1783 *
1784 * [number of saveable pages] - [number of pages that can be freed in theory]
1785 *
1786 * where the second term is the sum of (1) reclaimable slab pages, (2) active
1787 * and (3) inactive anonymous pages, (4) active and (5) inactive file pages.
1788 */
1789static unsigned long minimum_image_size(unsigned long saveable)
1790{
1791 unsigned long size;
1792
1793 size = global_node_page_state_pages(item: NR_SLAB_RECLAIMABLE_B)
1794 + global_node_page_state(item: NR_ACTIVE_ANON)
1795 + global_node_page_state(item: NR_INACTIVE_ANON)
1796 + global_node_page_state(item: NR_ACTIVE_FILE)
1797 + global_node_page_state(item: NR_INACTIVE_FILE);
1798
1799 return saveable <= size ? 0 : saveable - size;
1800}
1801
1802/**
1803 * hibernate_preallocate_memory - Preallocate memory for hibernation image.
1804 *
1805 * To create a hibernation image it is necessary to make a copy of every page
1806 * frame in use. We also need a number of page frames to be free during
1807 * hibernation for allocations made while saving the image and for device
1808 * drivers, in case they need to allocate memory from their hibernation
1809 * callbacks (these two numbers are given by PAGES_FOR_IO (which is a rough
1810 * estimate) and reserved_size divided by PAGE_SIZE (which is tunable through
1811 * /sys/power/reserved_size, respectively). To make this happen, we compute the
1812 * total number of available page frames and allocate at least
1813 *
1814 * ([page frames total] - PAGES_FOR_IO - [metadata pages]) / 2
1815 * - 2 * DIV_ROUND_UP(reserved_size, PAGE_SIZE)
1816 *
1817 * of them, which corresponds to the maximum size of a hibernation image.
1818 *
1819 * If image_size is set below the number following from the above formula,
1820 * the preallocation of memory is continued until the total number of saveable
1821 * pages in the system is below the requested image size or the minimum
1822 * acceptable image size returned by minimum_image_size(), whichever is greater.
1823 */
1824int hibernate_preallocate_memory(void)
1825{
1826 struct zone *zone;
1827 unsigned long saveable, size, max_size, count, highmem, pages = 0;
1828 unsigned long alloc, save_highmem, pages_highmem, avail_normal;
1829 ktime_t start, stop;
1830 int error;
1831
1832 pr_info("Preallocating image memory\n");
1833 start = ktime_get();
1834
1835 error = memory_bm_create(bm: &orig_bm, GFP_IMAGE, PG_ANY);
1836 if (error) {
1837 pr_err("Cannot allocate original bitmap\n");
1838 goto err_out;
1839 }
1840
1841 error = memory_bm_create(bm: &copy_bm, GFP_IMAGE, PG_ANY);
1842 if (error) {
1843 pr_err("Cannot allocate copy bitmap\n");
1844 goto err_out;
1845 }
1846
1847 error = memory_bm_create(bm: &zero_bm, GFP_IMAGE, PG_ANY);
1848 if (error) {
1849 pr_err("Cannot allocate zero bitmap\n");
1850 goto err_out;
1851 }
1852
1853 alloc_normal = 0;
1854 alloc_highmem = 0;
1855 nr_zero_pages = 0;
1856
1857 /* Count the number of saveable data pages. */
1858 save_highmem = count_highmem_pages();
1859 saveable = count_data_pages();
1860
1861 /*
1862 * Compute the total number of page frames we can use (count) and the
1863 * number of pages needed for image metadata (size).
1864 */
1865 count = saveable;
1866 saveable += save_highmem;
1867 highmem = save_highmem;
1868 size = 0;
1869 for_each_populated_zone(zone) {
1870 size += snapshot_additional_pages(zone);
1871 if (is_highmem(zone))
1872 highmem += zone_page_state(zone, item: NR_FREE_PAGES);
1873 else
1874 count += zone_page_state(zone, item: NR_FREE_PAGES);
1875 }
1876 avail_normal = count;
1877 count += highmem;
1878 count -= totalreserve_pages;
1879
1880 /* Compute the maximum number of saveable pages to leave in memory. */
1881 max_size = (count - (size + PAGES_FOR_IO)) / 2
1882 - 2 * DIV_ROUND_UP(reserved_size, PAGE_SIZE);
1883 /* Compute the desired number of image pages specified by image_size. */
1884 size = DIV_ROUND_UP(image_size, PAGE_SIZE);
1885 if (size > max_size)
1886 size = max_size;
1887 /*
1888 * If the desired number of image pages is at least as large as the
1889 * current number of saveable pages in memory, allocate page frames for
1890 * the image and we're done.
1891 */
1892 if (size >= saveable) {
1893 pages = preallocate_image_highmem(nr_pages: save_highmem);
1894 pages += preallocate_image_memory(nr_pages: saveable - pages, avail_normal);
1895 goto out;
1896 }
1897
1898 /* Estimate the minimum size of the image. */
1899 pages = minimum_image_size(saveable);
1900 /*
1901 * To avoid excessive pressure on the normal zone, leave room in it to
1902 * accommodate an image of the minimum size (unless it's already too
1903 * small, in which case don't preallocate pages from it at all).
1904 */
1905 if (avail_normal > pages)
1906 avail_normal -= pages;
1907 else
1908 avail_normal = 0;
1909 if (size < pages)
1910 size = min_t(unsigned long, pages, max_size);
1911
1912 /*
1913 * Let the memory management subsystem know that we're going to need a
1914 * large number of page frames to allocate and make it free some memory.
1915 * NOTE: If this is not done, performance will be hurt badly in some
1916 * test cases.
1917 */
1918 shrink_all_memory(nr_pages: saveable - size);
1919
1920 /*
1921 * The number of saveable pages in memory was too high, so apply some
1922 * pressure to decrease it. First, make room for the largest possible
1923 * image and fail if that doesn't work. Next, try to decrease the size
1924 * of the image as much as indicated by 'size' using allocations from
1925 * highmem and non-highmem zones separately.
1926 */
1927 pages_highmem = preallocate_image_highmem(nr_pages: highmem / 2);
1928 alloc = count - max_size;
1929 if (alloc > pages_highmem)
1930 alloc -= pages_highmem;
1931 else
1932 alloc = 0;
1933 pages = preallocate_image_memory(nr_pages: alloc, avail_normal);
1934 if (pages < alloc) {
1935 /* We have exhausted non-highmem pages, try highmem. */
1936 alloc -= pages;
1937 pages += pages_highmem;
1938 pages_highmem = preallocate_image_highmem(nr_pages: alloc);
1939 if (pages_highmem < alloc) {
1940 pr_err("Image allocation is %lu pages short\n",
1941 alloc - pages_highmem);
1942 goto err_out;
1943 }
1944 pages += pages_highmem;
1945 /*
1946 * size is the desired number of saveable pages to leave in
1947 * memory, so try to preallocate (all memory - size) pages.
1948 */
1949 alloc = (count - pages) - size;
1950 pages += preallocate_image_highmem(nr_pages: alloc);
1951 } else {
1952 /*
1953 * There are approximately max_size saveable pages at this point
1954 * and we want to reduce this number down to size.
1955 */
1956 alloc = max_size - size;
1957 size = preallocate_highmem_fraction(nr_pages: alloc, highmem, total: count);
1958 pages_highmem += size;
1959 alloc -= size;
1960 size = preallocate_image_memory(nr_pages: alloc, avail_normal);
1961 pages_highmem += preallocate_image_highmem(nr_pages: alloc - size);
1962 pages += pages_highmem + size;
1963 }
1964
1965 /*
1966 * We only need as many page frames for the image as there are saveable
1967 * pages in memory, but we have allocated more. Release the excessive
1968 * ones now.
1969 */
1970 pages -= free_unnecessary_pages();
1971
1972 out:
1973 stop = ktime_get();
1974 pr_info("Allocated %lu pages for snapshot\n", pages);
1975 swsusp_show_speed(start, stop, pages, "Allocated");
1976
1977 return 0;
1978
1979 err_out:
1980 swsusp_free();
1981 return -ENOMEM;
1982}
1983
1984#ifdef CONFIG_HIGHMEM
1985/**
1986 * count_pages_for_highmem - Count non-highmem pages needed for copying highmem.
1987 *
1988 * Compute the number of non-highmem pages that will be necessary for creating
1989 * copies of highmem pages.
1990 */
1991static unsigned int count_pages_for_highmem(unsigned int nr_highmem)
1992{
1993 unsigned int free_highmem = count_free_highmem_pages() + alloc_highmem;
1994
1995 if (free_highmem >= nr_highmem)
1996 nr_highmem = 0;
1997 else
1998 nr_highmem -= free_highmem;
1999
2000 return nr_highmem;
2001}
2002#else
2003static unsigned int count_pages_for_highmem(unsigned int nr_highmem) { return 0; }
2004#endif /* CONFIG_HIGHMEM */
2005
2006/**
2007 * enough_free_mem - Check if there is enough free memory for the image.
2008 */
2009static int enough_free_mem(unsigned int nr_pages, unsigned int nr_highmem)
2010{
2011 struct zone *zone;
2012 unsigned int free = alloc_normal;
2013
2014 for_each_populated_zone(zone)
2015 if (!is_highmem(zone))
2016 free += zone_page_state(zone, item: NR_FREE_PAGES);
2017
2018 nr_pages += count_pages_for_highmem(nr_highmem);
2019 pr_debug("Normal pages needed: %u + %u, available pages: %u\n",
2020 nr_pages, PAGES_FOR_IO, free);
2021
2022 return free > nr_pages + PAGES_FOR_IO;
2023}
2024
2025#ifdef CONFIG_HIGHMEM
2026/**
2027 * get_highmem_buffer - Allocate a buffer for highmem pages.
2028 *
2029 * If there are some highmem pages in the hibernation image, we may need a
2030 * buffer to copy them and/or load their data.
2031 */
2032static inline int get_highmem_buffer(int safe_needed)
2033{
2034 buffer = get_image_page(GFP_ATOMIC, safe_needed);
2035 return buffer ? 0 : -ENOMEM;
2036}
2037
2038/**
2039 * alloc_highmem_pages - Allocate some highmem pages for the image.
2040 *
2041 * Try to allocate as many pages as needed, but if the number of free highmem
2042 * pages is less than that, allocate them all.
2043 */
2044static inline unsigned int alloc_highmem_pages(struct memory_bitmap *bm,
2045 unsigned int nr_highmem)
2046{
2047 unsigned int to_alloc = count_free_highmem_pages();
2048
2049 if (to_alloc > nr_highmem)
2050 to_alloc = nr_highmem;
2051
2052 nr_highmem -= to_alloc;
2053 while (to_alloc-- > 0) {
2054 struct page *page;
2055
2056 page = alloc_image_page(__GFP_HIGHMEM|__GFP_KSWAPD_RECLAIM);
2057 memory_bm_set_bit(bm, page_to_pfn(page));
2058 }
2059 return nr_highmem;
2060}
2061#else
2062static inline int get_highmem_buffer(int safe_needed) { return 0; }
2063
2064static inline unsigned int alloc_highmem_pages(struct memory_bitmap *bm,
2065 unsigned int n) { return 0; }
2066#endif /* CONFIG_HIGHMEM */
2067
2068/**
2069 * swsusp_alloc - Allocate memory for hibernation image.
2070 *
2071 * We first try to allocate as many highmem pages as there are
2072 * saveable highmem pages in the system. If that fails, we allocate
2073 * non-highmem pages for the copies of the remaining highmem ones.
2074 *
2075 * In this approach it is likely that the copies of highmem pages will
2076 * also be located in the high memory, because of the way in which
2077 * copy_data_pages() works.
2078 */
2079static int swsusp_alloc(struct memory_bitmap *copy_bm,
2080 unsigned int nr_pages, unsigned int nr_highmem)
2081{
2082 if (nr_highmem > 0) {
2083 if (get_highmem_buffer(PG_ANY))
2084 goto err_out;
2085 if (nr_highmem > alloc_highmem) {
2086 nr_highmem -= alloc_highmem;
2087 nr_pages += alloc_highmem_pages(bm: copy_bm, n: nr_highmem);
2088 }
2089 }
2090 if (nr_pages > alloc_normal) {
2091 nr_pages -= alloc_normal;
2092 while (nr_pages-- > 0) {
2093 struct page *page;
2094
2095 page = alloc_image_page(GFP_ATOMIC);
2096 if (!page)
2097 goto err_out;
2098 memory_bm_set_bit(bm: copy_bm, page_to_pfn(page));
2099 }
2100 }
2101
2102 return 0;
2103
2104 err_out:
2105 swsusp_free();
2106 return -ENOMEM;
2107}
2108
2109asmlinkage __visible int swsusp_save(void)
2110{
2111 unsigned int nr_pages, nr_highmem;
2112
2113 pr_info("Creating image:\n");
2114
2115 drain_local_pages(NULL);
2116 nr_pages = count_data_pages();
2117 nr_highmem = count_highmem_pages();
2118 pr_info("Need to copy %u pages\n", nr_pages + nr_highmem);
2119
2120 if (!enough_free_mem(nr_pages, nr_highmem)) {
2121 pr_err("Not enough free memory\n");
2122 return -ENOMEM;
2123 }
2124
2125 if (swsusp_alloc(copy_bm: &copy_bm, nr_pages, nr_highmem)) {
2126 pr_err("Memory allocation failed\n");
2127 return -ENOMEM;
2128 }
2129
2130 /*
2131 * During allocating of suspend pagedir, new cold pages may appear.
2132 * Kill them.
2133 */
2134 drain_local_pages(NULL);
2135 nr_copy_pages = copy_data_pages(copy_bm: &copy_bm, orig_bm: &orig_bm, zero_bm: &zero_bm);
2136
2137 /*
2138 * End of critical section. From now on, we can write to memory,
2139 * but we should not touch disk. This specially means we must _not_
2140 * touch swap space! Except we must write out our image of course.
2141 */
2142 nr_pages += nr_highmem;
2143 /* We don't actually copy the zero pages */
2144 nr_zero_pages = nr_pages - nr_copy_pages;
2145 nr_meta_pages = DIV_ROUND_UP(nr_pages * sizeof(long), PAGE_SIZE);
2146
2147 pr_info("Image created (%d pages copied, %d zero pages)\n", nr_copy_pages, nr_zero_pages);
2148
2149 return 0;
2150}
2151
2152#ifndef CONFIG_ARCH_HIBERNATION_HEADER
2153static int init_header_complete(struct swsusp_info *info)
2154{
2155 memcpy(&info->uts, init_utsname(), sizeof(struct new_utsname));
2156 info->version_code = LINUX_VERSION_CODE;
2157 return 0;
2158}
2159
2160static const char *check_image_kernel(struct swsusp_info *info)
2161{
2162 if (info->version_code != LINUX_VERSION_CODE)
2163 return "kernel version";
2164 if (strcmp(info->uts.sysname, init_utsname()->sysname))
2165 return "system type";
2166 if (strcmp(info->uts.release, init_utsname()->release))
2167 return "kernel release";
2168 if (strcmp(info->uts.version, init_utsname()->version))
2169 return "version";
2170 if (strcmp(info->uts.machine, init_utsname()->machine))
2171 return "machine";
2172 return NULL;
2173}
2174#endif /* CONFIG_ARCH_HIBERNATION_HEADER */
2175
2176unsigned long snapshot_get_image_size(void)
2177{
2178 return nr_copy_pages + nr_meta_pages + 1;
2179}
2180
2181static int init_header(struct swsusp_info *info)
2182{
2183 memset(s: info, c: 0, n: sizeof(struct swsusp_info));
2184 info->num_physpages = get_num_physpages();
2185 info->image_pages = nr_copy_pages;
2186 info->pages = snapshot_get_image_size();
2187 info->size = info->pages;
2188 info->size <<= PAGE_SHIFT;
2189 return init_header_complete(info);
2190}
2191
2192#define ENCODED_PFN_ZERO_FLAG ((unsigned long)1 << (BITS_PER_LONG - 1))
2193#define ENCODED_PFN_MASK (~ENCODED_PFN_ZERO_FLAG)
2194
2195/**
2196 * pack_pfns - Prepare PFNs for saving.
2197 * @bm: Memory bitmap.
2198 * @buf: Memory buffer to store the PFNs in.
2199 * @zero_bm: Memory bitmap containing PFNs of zero pages.
2200 *
2201 * PFNs corresponding to set bits in @bm are stored in the area of memory
2202 * pointed to by @buf (1 page at a time). Pages which were filled with only
2203 * zeros will have the highest bit set in the packed format to distinguish
2204 * them from PFNs which will be contained in the image file.
2205 */
2206static inline void pack_pfns(unsigned long *buf, struct memory_bitmap *bm,
2207 struct memory_bitmap *zero_bm)
2208{
2209 int j;
2210
2211 for (j = 0; j < PAGE_SIZE / sizeof(long); j++) {
2212 buf[j] = memory_bm_next_pfn(bm);
2213 if (unlikely(buf[j] == BM_END_OF_MAP))
2214 break;
2215 if (memory_bm_test_bit(bm: zero_bm, pfn: buf[j]))
2216 buf[j] |= ENCODED_PFN_ZERO_FLAG;
2217 }
2218}
2219
2220/**
2221 * snapshot_read_next - Get the address to read the next image page from.
2222 * @handle: Snapshot handle to be used for the reading.
2223 *
2224 * On the first call, @handle should point to a zeroed snapshot_handle
2225 * structure. The structure gets populated then and a pointer to it should be
2226 * passed to this function every next time.
2227 *
2228 * On success, the function returns a positive number. Then, the caller
2229 * is allowed to read up to the returned number of bytes from the memory
2230 * location computed by the data_of() macro.
2231 *
2232 * The function returns 0 to indicate the end of the data stream condition,
2233 * and negative numbers are returned on errors. If that happens, the structure
2234 * pointed to by @handle is not updated and should not be used any more.
2235 */
2236int snapshot_read_next(struct snapshot_handle *handle)
2237{
2238 if (handle->cur > nr_meta_pages + nr_copy_pages)
2239 return 0;
2240
2241 if (!buffer) {
2242 /* This makes the buffer be freed by swsusp_free() */
2243 buffer = get_image_page(GFP_ATOMIC, PG_ANY);
2244 if (!buffer)
2245 return -ENOMEM;
2246 }
2247 if (!handle->cur) {
2248 int error;
2249
2250 error = init_header(info: (struct swsusp_info *)buffer);
2251 if (error)
2252 return error;
2253 handle->buffer = buffer;
2254 memory_bm_position_reset(bm: &orig_bm);
2255 memory_bm_position_reset(bm: &copy_bm);
2256 } else if (handle->cur <= nr_meta_pages) {
2257 clear_page(page: buffer);
2258 pack_pfns(buf: buffer, bm: &orig_bm, zero_bm: &zero_bm);
2259 } else {
2260 struct page *page;
2261
2262 page = pfn_to_page(memory_bm_next_pfn(&copy_bm));
2263 if (PageHighMem(page)) {
2264 /*
2265 * Highmem pages are copied to the buffer,
2266 * because we can't return with a kmapped
2267 * highmem page (we may not be called again).
2268 */
2269 void *kaddr;
2270
2271 kaddr = kmap_local_page(page);
2272 copy_page(to: buffer, from: kaddr);
2273 kunmap_local(kaddr);
2274 handle->buffer = buffer;
2275 } else {
2276 handle->buffer = page_address(page);
2277 }
2278 }
2279 handle->cur++;
2280 return PAGE_SIZE;
2281}
2282
2283static void duplicate_memory_bitmap(struct memory_bitmap *dst,
2284 struct memory_bitmap *src)
2285{
2286 unsigned long pfn;
2287
2288 memory_bm_position_reset(bm: src);
2289 pfn = memory_bm_next_pfn(bm: src);
2290 while (pfn != BM_END_OF_MAP) {
2291 memory_bm_set_bit(bm: dst, pfn);
2292 pfn = memory_bm_next_pfn(bm: src);
2293 }
2294}
2295
2296/**
2297 * mark_unsafe_pages - Mark pages that were used before hibernation.
2298 *
2299 * Mark the pages that cannot be used for storing the image during restoration,
2300 * because they conflict with the pages that had been used before hibernation.
2301 */
2302static void mark_unsafe_pages(struct memory_bitmap *bm)
2303{
2304 unsigned long pfn;
2305
2306 /* Clear the "free"/"unsafe" bit for all PFNs */
2307 memory_bm_position_reset(bm: free_pages_map);
2308 pfn = memory_bm_next_pfn(bm: free_pages_map);
2309 while (pfn != BM_END_OF_MAP) {
2310 memory_bm_clear_current(bm: free_pages_map);
2311 pfn = memory_bm_next_pfn(bm: free_pages_map);
2312 }
2313
2314 /* Mark pages that correspond to the "original" PFNs as "unsafe" */
2315 duplicate_memory_bitmap(dst: free_pages_map, src: bm);
2316
2317 allocated_unsafe_pages = 0;
2318}
2319
2320static int check_header(struct swsusp_info *info)
2321{
2322 const char *reason;
2323
2324 reason = check_image_kernel(info);
2325 if (!reason && info->num_physpages != get_num_physpages())
2326 reason = "memory size";
2327 if (reason) {
2328 pr_err("Image mismatch: %s\n", reason);
2329 return -EPERM;
2330 }
2331 return 0;
2332}
2333
2334/**
2335 * load_header - Check the image header and copy the data from it.
2336 */
2337static int load_header(struct swsusp_info *info)
2338{
2339 int error;
2340
2341 restore_pblist = NULL;
2342 error = check_header(info);
2343 if (!error) {
2344 nr_copy_pages = info->image_pages;
2345 nr_meta_pages = info->pages - info->image_pages - 1;
2346 }
2347 return error;
2348}
2349
2350/**
2351 * unpack_orig_pfns - Set bits corresponding to given PFNs in a memory bitmap.
2352 * @bm: Memory bitmap.
2353 * @buf: Area of memory containing the PFNs.
2354 * @zero_bm: Memory bitmap with the zero PFNs marked.
2355 *
2356 * For each element of the array pointed to by @buf (1 page at a time), set the
2357 * corresponding bit in @bm. If the page was originally populated with only
2358 * zeros then a corresponding bit will also be set in @zero_bm.
2359 */
2360static int unpack_orig_pfns(unsigned long *buf, struct memory_bitmap *bm,
2361 struct memory_bitmap *zero_bm)
2362{
2363 unsigned long decoded_pfn;
2364 bool zero;
2365 int j;
2366
2367 for (j = 0; j < PAGE_SIZE / sizeof(long); j++) {
2368 if (unlikely(buf[j] == BM_END_OF_MAP))
2369 break;
2370
2371 zero = !!(buf[j] & ENCODED_PFN_ZERO_FLAG);
2372 decoded_pfn = buf[j] & ENCODED_PFN_MASK;
2373 if (pfn_valid(pfn: decoded_pfn) && memory_bm_pfn_present(bm, pfn: decoded_pfn)) {
2374 memory_bm_set_bit(bm, pfn: decoded_pfn);
2375 if (zero) {
2376 memory_bm_set_bit(bm: zero_bm, pfn: decoded_pfn);
2377 nr_zero_pages++;
2378 }
2379 } else {
2380 if (!pfn_valid(pfn: decoded_pfn))
2381 pr_err(FW_BUG "Memory map mismatch at 0x%llx after hibernation\n",
2382 (unsigned long long)PFN_PHYS(decoded_pfn));
2383 return -EFAULT;
2384 }
2385 }
2386
2387 return 0;
2388}
2389
2390#ifdef CONFIG_HIGHMEM
2391/*
2392 * struct highmem_pbe is used for creating the list of highmem pages that
2393 * should be restored atomically during the resume from disk, because the page
2394 * frames they have occupied before the suspend are in use.
2395 */
2396struct highmem_pbe {
2397 struct page *copy_page; /* data is here now */
2398 struct page *orig_page; /* data was here before the suspend */
2399 struct highmem_pbe *next;
2400};
2401
2402/*
2403 * List of highmem PBEs needed for restoring the highmem pages that were
2404 * allocated before the suspend and included in the suspend image, but have
2405 * also been allocated by the "resume" kernel, so their contents cannot be
2406 * written directly to their "original" page frames.
2407 */
2408static struct highmem_pbe *highmem_pblist;
2409
2410/**
2411 * count_highmem_image_pages - Compute the number of highmem pages in the image.
2412 * @bm: Memory bitmap.
2413 *
2414 * The bits in @bm that correspond to image pages are assumed to be set.
2415 */
2416static unsigned int count_highmem_image_pages(struct memory_bitmap *bm)
2417{
2418 unsigned long pfn;
2419 unsigned int cnt = 0;
2420
2421 memory_bm_position_reset(bm);
2422 pfn = memory_bm_next_pfn(bm);
2423 while (pfn != BM_END_OF_MAP) {
2424 if (PageHighMem(pfn_to_page(pfn)))
2425 cnt++;
2426
2427 pfn = memory_bm_next_pfn(bm);
2428 }
2429 return cnt;
2430}
2431
2432static unsigned int safe_highmem_pages;
2433
2434static struct memory_bitmap *safe_highmem_bm;
2435
2436/**
2437 * prepare_highmem_image - Allocate memory for loading highmem data from image.
2438 * @bm: Pointer to an uninitialized memory bitmap structure.
2439 * @nr_highmem_p: Pointer to the number of highmem image pages.
2440 *
2441 * Try to allocate as many highmem pages as there are highmem image pages
2442 * (@nr_highmem_p points to the variable containing the number of highmem image
2443 * pages). The pages that are "safe" (ie. will not be overwritten when the
2444 * hibernation image is restored entirely) have the corresponding bits set in
2445 * @bm (it must be uninitialized).
2446 *
2447 * NOTE: This function should not be called if there are no highmem image pages.
2448 */
2449static int prepare_highmem_image(struct memory_bitmap *bm,
2450 unsigned int *nr_highmem_p)
2451{
2452 unsigned int to_alloc;
2453
2454 if (memory_bm_create(bm, GFP_ATOMIC, PG_SAFE))
2455 return -ENOMEM;
2456
2457 if (get_highmem_buffer(PG_SAFE))
2458 return -ENOMEM;
2459
2460 to_alloc = count_free_highmem_pages();
2461 if (to_alloc > *nr_highmem_p)
2462 to_alloc = *nr_highmem_p;
2463 else
2464 *nr_highmem_p = to_alloc;
2465
2466 safe_highmem_pages = 0;
2467 while (to_alloc-- > 0) {
2468 struct page *page;
2469
2470 page = alloc_page(__GFP_HIGHMEM);
2471 if (!swsusp_page_is_free(page)) {
2472 /* The page is "safe", set its bit the bitmap */
2473 memory_bm_set_bit(bm, page_to_pfn(page));
2474 safe_highmem_pages++;
2475 }
2476 /* Mark the page as allocated */
2477 swsusp_set_page_forbidden(page);
2478 swsusp_set_page_free(page);
2479 }
2480 memory_bm_position_reset(bm);
2481 safe_highmem_bm = bm;
2482 return 0;
2483}
2484
2485static struct page *last_highmem_page;
2486
2487/**
2488 * get_highmem_page_buffer - Prepare a buffer to store a highmem image page.
2489 *
2490 * For a given highmem image page get a buffer that suspend_write_next() should
2491 * return to its caller to write to.
2492 *
2493 * If the page is to be saved to its "original" page frame or a copy of
2494 * the page is to be made in the highmem, @buffer is returned. Otherwise,
2495 * the copy of the page is to be made in normal memory, so the address of
2496 * the copy is returned.
2497 *
2498 * If @buffer is returned, the caller of suspend_write_next() will write
2499 * the page's contents to @buffer, so they will have to be copied to the
2500 * right location on the next call to suspend_write_next() and it is done
2501 * with the help of copy_last_highmem_page(). For this purpose, if
2502 * @buffer is returned, @last_highmem_page is set to the page to which
2503 * the data will have to be copied from @buffer.
2504 */
2505static void *get_highmem_page_buffer(struct page *page,
2506 struct chain_allocator *ca)
2507{
2508 struct highmem_pbe *pbe;
2509 void *kaddr;
2510
2511 if (swsusp_page_is_forbidden(page) && swsusp_page_is_free(page)) {
2512 /*
2513 * We have allocated the "original" page frame and we can
2514 * use it directly to store the loaded page.
2515 */
2516 last_highmem_page = page;
2517 return buffer;
2518 }
2519 /*
2520 * The "original" page frame has not been allocated and we have to
2521 * use a "safe" page frame to store the loaded page.
2522 */
2523 pbe = chain_alloc(ca, sizeof(struct highmem_pbe));
2524 if (!pbe) {
2525 swsusp_free();
2526 return ERR_PTR(-ENOMEM);
2527 }
2528 pbe->orig_page = page;
2529 if (safe_highmem_pages > 0) {
2530 struct page *tmp;
2531
2532 /* Copy of the page will be stored in high memory */
2533 kaddr = buffer;
2534 tmp = pfn_to_page(memory_bm_next_pfn(safe_highmem_bm));
2535 safe_highmem_pages--;
2536 last_highmem_page = tmp;
2537 pbe->copy_page = tmp;
2538 } else {
2539 /* Copy of the page will be stored in normal memory */
2540 kaddr = __get_safe_page(ca->gfp_mask);
2541 if (!kaddr)
2542 return ERR_PTR(-ENOMEM);
2543 pbe->copy_page = virt_to_page(kaddr);
2544 }
2545 pbe->next = highmem_pblist;
2546 highmem_pblist = pbe;
2547 return kaddr;
2548}
2549
2550/**
2551 * copy_last_highmem_page - Copy most the most recent highmem image page.
2552 *
2553 * Copy the contents of a highmem image from @buffer, where the caller of
2554 * snapshot_write_next() has stored them, to the right location represented by
2555 * @last_highmem_page .
2556 */
2557static void copy_last_highmem_page(void)
2558{
2559 if (last_highmem_page) {
2560 void *dst;
2561
2562 dst = kmap_local_page(last_highmem_page);
2563 copy_page(dst, buffer);
2564 kunmap_local(dst);
2565 last_highmem_page = NULL;
2566 }
2567}
2568
2569static inline int last_highmem_page_copied(void)
2570{
2571 return !last_highmem_page;
2572}
2573
2574static inline void free_highmem_data(void)
2575{
2576 if (safe_highmem_bm)
2577 memory_bm_free(safe_highmem_bm, PG_UNSAFE_CLEAR);
2578
2579 if (buffer)
2580 free_image_page(buffer, PG_UNSAFE_CLEAR);
2581}
2582#else
2583static unsigned int count_highmem_image_pages(struct memory_bitmap *bm) { return 0; }
2584
2585static inline int prepare_highmem_image(struct memory_bitmap *bm,
2586 unsigned int *nr_highmem_p) { return 0; }
2587
2588static inline void *get_highmem_page_buffer(struct page *page,
2589 struct chain_allocator *ca)
2590{
2591 return ERR_PTR(error: -EINVAL);
2592}
2593
2594static inline void copy_last_highmem_page(void) {}
2595static inline int last_highmem_page_copied(void) { return 1; }
2596static inline void free_highmem_data(void) {}
2597#endif /* CONFIG_HIGHMEM */
2598
2599#define PBES_PER_LINKED_PAGE (LINKED_PAGE_DATA_SIZE / sizeof(struct pbe))
2600
2601/**
2602 * prepare_image - Make room for loading hibernation image.
2603 * @new_bm: Uninitialized memory bitmap structure.
2604 * @bm: Memory bitmap with unsafe pages marked.
2605 * @zero_bm: Memory bitmap containing the zero pages.
2606 *
2607 * Use @bm to mark the pages that will be overwritten in the process of
2608 * restoring the system memory state from the suspend image ("unsafe" pages)
2609 * and allocate memory for the image.
2610 *
2611 * The idea is to allocate a new memory bitmap first and then allocate
2612 * as many pages as needed for image data, but without specifying what those
2613 * pages will be used for just yet. Instead, we mark them all as allocated and
2614 * create a lists of "safe" pages to be used later. On systems with high
2615 * memory a list of "safe" highmem pages is created too.
2616 *
2617 * Because it was not known which pages were unsafe when @zero_bm was created,
2618 * make a copy of it and recreate it within safe pages.
2619 */
2620static int prepare_image(struct memory_bitmap *new_bm, struct memory_bitmap *bm,
2621 struct memory_bitmap *zero_bm)
2622{
2623 unsigned int nr_pages, nr_highmem;
2624 struct memory_bitmap tmp;
2625 struct linked_page *lp;
2626 int error;
2627
2628 /* If there is no highmem, the buffer will not be necessary */
2629 free_image_page(addr: buffer, PG_UNSAFE_CLEAR);
2630 buffer = NULL;
2631
2632 nr_highmem = count_highmem_image_pages(bm);
2633 mark_unsafe_pages(bm);
2634
2635 error = memory_bm_create(bm: new_bm, GFP_ATOMIC, PG_SAFE);
2636 if (error)
2637 goto Free;
2638
2639 duplicate_memory_bitmap(dst: new_bm, src: bm);
2640 memory_bm_free(bm, PG_UNSAFE_KEEP);
2641
2642 /* Make a copy of zero_bm so it can be created in safe pages */
2643 error = memory_bm_create(bm: &tmp, GFP_ATOMIC, PG_SAFE);
2644 if (error)
2645 goto Free;
2646
2647 duplicate_memory_bitmap(dst: &tmp, src: zero_bm);
2648 memory_bm_free(bm: zero_bm, PG_UNSAFE_KEEP);
2649
2650 /* Recreate zero_bm in safe pages */
2651 error = memory_bm_create(bm: zero_bm, GFP_ATOMIC, PG_SAFE);
2652 if (error)
2653 goto Free;
2654
2655 duplicate_memory_bitmap(dst: zero_bm, src: &tmp);
2656 memory_bm_free(bm: &tmp, PG_UNSAFE_CLEAR);
2657 /* At this point zero_bm is in safe pages and it can be used for restoring. */
2658
2659 if (nr_highmem > 0) {
2660 error = prepare_highmem_image(bm, nr_highmem_p: &nr_highmem);
2661 if (error)
2662 goto Free;
2663 }
2664 /*
2665 * Reserve some safe pages for potential later use.
2666 *
2667 * NOTE: This way we make sure there will be enough safe pages for the
2668 * chain_alloc() in get_buffer(). It is a bit wasteful, but
2669 * nr_copy_pages cannot be greater than 50% of the memory anyway.
2670 *
2671 * nr_copy_pages cannot be less than allocated_unsafe_pages too.
2672 */
2673 nr_pages = (nr_zero_pages + nr_copy_pages) - nr_highmem - allocated_unsafe_pages;
2674 nr_pages = DIV_ROUND_UP(nr_pages, PBES_PER_LINKED_PAGE);
2675 while (nr_pages > 0) {
2676 lp = get_image_page(GFP_ATOMIC, PG_SAFE);
2677 if (!lp) {
2678 error = -ENOMEM;
2679 goto Free;
2680 }
2681 lp->next = safe_pages_list;
2682 safe_pages_list = lp;
2683 nr_pages--;
2684 }
2685 /* Preallocate memory for the image */
2686 nr_pages = (nr_zero_pages + nr_copy_pages) - nr_highmem - allocated_unsafe_pages;
2687 while (nr_pages > 0) {
2688 lp = (struct linked_page *)get_zeroed_page(GFP_ATOMIC);
2689 if (!lp) {
2690 error = -ENOMEM;
2691 goto Free;
2692 }
2693 if (!swsusp_page_is_free(virt_to_page(lp))) {
2694 /* The page is "safe", add it to the list */
2695 lp->next = safe_pages_list;
2696 safe_pages_list = lp;
2697 }
2698 /* Mark the page as allocated */
2699 swsusp_set_page_forbidden(virt_to_page(lp));
2700 swsusp_set_page_free(virt_to_page(lp));
2701 nr_pages--;
2702 }
2703 return 0;
2704
2705 Free:
2706 swsusp_free();
2707 return error;
2708}
2709
2710/**
2711 * get_buffer - Get the address to store the next image data page.
2712 *
2713 * Get the address that snapshot_write_next() should return to its caller to
2714 * write to.
2715 */
2716static void *get_buffer(struct memory_bitmap *bm, struct chain_allocator *ca)
2717{
2718 struct pbe *pbe;
2719 struct page *page;
2720 unsigned long pfn = memory_bm_next_pfn(bm);
2721
2722 if (pfn == BM_END_OF_MAP)
2723 return ERR_PTR(error: -EFAULT);
2724
2725 page = pfn_to_page(pfn);
2726 if (PageHighMem(page))
2727 return get_highmem_page_buffer(page, ca);
2728
2729 if (swsusp_page_is_forbidden(page) && swsusp_page_is_free(page))
2730 /*
2731 * We have allocated the "original" page frame and we can
2732 * use it directly to store the loaded page.
2733 */
2734 return page_address(page);
2735
2736 /*
2737 * The "original" page frame has not been allocated and we have to
2738 * use a "safe" page frame to store the loaded page.
2739 */
2740 pbe = chain_alloc(ca, size: sizeof(struct pbe));
2741 if (!pbe) {
2742 swsusp_free();
2743 return ERR_PTR(error: -ENOMEM);
2744 }
2745 pbe->orig_address = page_address(page);
2746 pbe->address = __get_safe_page(gfp_mask: ca->gfp_mask);
2747 if (!pbe->address)
2748 return ERR_PTR(error: -ENOMEM);
2749 pbe->next = restore_pblist;
2750 restore_pblist = pbe;
2751 return pbe->address;
2752}
2753
2754/**
2755 * snapshot_write_next - Get the address to store the next image page.
2756 * @handle: Snapshot handle structure to guide the writing.
2757 *
2758 * On the first call, @handle should point to a zeroed snapshot_handle
2759 * structure. The structure gets populated then and a pointer to it should be
2760 * passed to this function every next time.
2761 *
2762 * On success, the function returns a positive number. Then, the caller
2763 * is allowed to write up to the returned number of bytes to the memory
2764 * location computed by the data_of() macro.
2765 *
2766 * The function returns 0 to indicate the "end of file" condition. Negative
2767 * numbers are returned on errors, in which cases the structure pointed to by
2768 * @handle is not updated and should not be used any more.
2769 */
2770int snapshot_write_next(struct snapshot_handle *handle)
2771{
2772 static struct chain_allocator ca;
2773 int error;
2774
2775next:
2776 /* Check if we have already loaded the entire image */
2777 if (handle->cur > 1 && handle->cur > nr_meta_pages + nr_copy_pages + nr_zero_pages)
2778 return 0;
2779
2780 if (!handle->cur) {
2781 if (!buffer)
2782 /* This makes the buffer be freed by swsusp_free() */
2783 buffer = get_image_page(GFP_ATOMIC, PG_ANY);
2784
2785 if (!buffer)
2786 return -ENOMEM;
2787
2788 handle->buffer = buffer;
2789 } else if (handle->cur == 1) {
2790 error = load_header(info: buffer);
2791 if (error)
2792 return error;
2793
2794 safe_pages_list = NULL;
2795
2796 error = memory_bm_create(bm: &copy_bm, GFP_ATOMIC, PG_ANY);
2797 if (error)
2798 return error;
2799
2800 error = memory_bm_create(bm: &zero_bm, GFP_ATOMIC, PG_ANY);
2801 if (error)
2802 return error;
2803
2804 nr_zero_pages = 0;
2805
2806 hibernate_restore_protection_begin();
2807 } else if (handle->cur <= nr_meta_pages + 1) {
2808 error = unpack_orig_pfns(buf: buffer, bm: &copy_bm, zero_bm: &zero_bm);
2809 if (error)
2810 return error;
2811
2812 if (handle->cur == nr_meta_pages + 1) {
2813 error = prepare_image(new_bm: &orig_bm, bm: &copy_bm, zero_bm: &zero_bm);
2814 if (error)
2815 return error;
2816
2817 chain_init(ca: &ca, GFP_ATOMIC, PG_SAFE);
2818 memory_bm_position_reset(bm: &orig_bm);
2819 memory_bm_position_reset(bm: &zero_bm);
2820 restore_pblist = NULL;
2821 handle->buffer = get_buffer(bm: &orig_bm, ca: &ca);
2822 if (IS_ERR(ptr: handle->buffer))
2823 return PTR_ERR(ptr: handle->buffer);
2824 }
2825 } else {
2826 copy_last_highmem_page();
2827 error = hibernate_restore_protect_page(page_address: handle->buffer);
2828 if (error)
2829 return error;
2830 handle->buffer = get_buffer(bm: &orig_bm, ca: &ca);
2831 if (IS_ERR(ptr: handle->buffer))
2832 return PTR_ERR(ptr: handle->buffer);
2833 }
2834 handle->sync_read = (handle->buffer == buffer);
2835 handle->cur++;
2836
2837 /* Zero pages were not included in the image, memset it and move on. */
2838 if (handle->cur > nr_meta_pages + 1 &&
2839 memory_bm_test_bit(bm: &zero_bm, pfn: memory_bm_get_current(bm: &orig_bm))) {
2840 memset(s: handle->buffer, c: 0, PAGE_SIZE);
2841 goto next;
2842 }
2843
2844 return PAGE_SIZE;
2845}
2846
2847/**
2848 * snapshot_write_finalize - Complete the loading of a hibernation image.
2849 *
2850 * Must be called after the last call to snapshot_write_next() in case the last
2851 * page in the image happens to be a highmem page and its contents should be
2852 * stored in highmem. Additionally, it recycles bitmap memory that's not
2853 * necessary any more.
2854 */
2855int snapshot_write_finalize(struct snapshot_handle *handle)
2856{
2857 int error;
2858
2859 copy_last_highmem_page();
2860 error = hibernate_restore_protect_page(page_address: handle->buffer);
2861 /* Do that only if we have loaded the image entirely */
2862 if (handle->cur > 1 && handle->cur > nr_meta_pages + nr_copy_pages + nr_zero_pages) {
2863 memory_bm_recycle(bm: &orig_bm);
2864 free_highmem_data();
2865 }
2866 return error;
2867}
2868
2869int snapshot_image_loaded(struct snapshot_handle *handle)
2870{
2871 return !(!nr_copy_pages || !last_highmem_page_copied() ||
2872 handle->cur <= nr_meta_pages + nr_copy_pages + nr_zero_pages);
2873}
2874
2875#ifdef CONFIG_HIGHMEM
2876/* Assumes that @buf is ready and points to a "safe" page */
2877static inline void swap_two_pages_data(struct page *p1, struct page *p2,
2878 void *buf)
2879{
2880 void *kaddr1, *kaddr2;
2881
2882 kaddr1 = kmap_local_page(p1);
2883 kaddr2 = kmap_local_page(p2);
2884 copy_page(buf, kaddr1);
2885 copy_page(kaddr1, kaddr2);
2886 copy_page(kaddr2, buf);
2887 kunmap_local(kaddr2);
2888 kunmap_local(kaddr1);
2889}
2890
2891/**
2892 * restore_highmem - Put highmem image pages into their original locations.
2893 *
2894 * For each highmem page that was in use before hibernation and is included in
2895 * the image, and also has been allocated by the "restore" kernel, swap its
2896 * current contents with the previous (ie. "before hibernation") ones.
2897 *
2898 * If the restore eventually fails, we can call this function once again and
2899 * restore the highmem state as seen by the restore kernel.
2900 */
2901int restore_highmem(void)
2902{
2903 struct highmem_pbe *pbe = highmem_pblist;
2904 void *buf;
2905
2906 if (!pbe)
2907 return 0;
2908
2909 buf = get_image_page(GFP_ATOMIC, PG_SAFE);
2910 if (!buf)
2911 return -ENOMEM;
2912
2913 while (pbe) {
2914 swap_two_pages_data(pbe->copy_page, pbe->orig_page, buf);
2915 pbe = pbe->next;
2916 }
2917 free_image_page(buf, PG_UNSAFE_CLEAR);
2918 return 0;
2919}
2920#endif /* CONFIG_HIGHMEM */
2921