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