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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/*
2 * linux/kernel/power/snapshot.c
3 *
4 * This file provides system snapshot/restore functionality for swsusp.
5 *
6 * Copyright (C) 1998-2005 Pavel Machek <pavel@ucw.cz>
7 * Copyright (C) 2006 Rafael J. Wysocki <rjw@sisk.pl>
8 *
9 * This file is released under the GPLv2.
10 *
11 */
12
13#define pr_fmt(fmt) "PM: " fmt
14
15#include <linux/version.h>
16#include <linux/module.h>
17#include <linux/mm.h>
18#include <linux/suspend.h>
19#include <linux/delay.h>
20#include <linux/bitops.h>
21#include <linux/spinlock.h>
22#include <linux/kernel.h>
23#include <linux/pm.h>
24#include <linux/device.h>
25#include <linux/init.h>
26#include <linux/bootmem.h>
27#include <linux/nmi.h>
28#include <linux/syscalls.h>
29#include <linux/console.h>
30#include <linux/highmem.h>
31#include <linux/list.h>
32#include <linux/slab.h>
33#include <linux/compiler.h>
34#include <linux/ktime.h>
35#include <linux/set_memory.h>
36
37#include <linux/uaccess.h>
38#include <asm/mmu_context.h>
39#include <asm/pgtable.h>
40#include <asm/tlbflush.h>
41#include <asm/io.h>
42
43#include "power.h"
44
45#if defined(CONFIG_STRICT_KERNEL_RWX) && defined(CONFIG_ARCH_HAS_SET_MEMORY)
46static bool hibernate_restore_protection;
47static bool hibernate_restore_protection_active;
48
49void enable_restore_image_protection(void)
50{
51 hibernate_restore_protection = true;
52}
53
54static inline void hibernate_restore_protection_begin(void)
55{
56 hibernate_restore_protection_active = hibernate_restore_protection;
57}
58
59static inline void hibernate_restore_protection_end(void)
60{
61 hibernate_restore_protection_active = false;
62}
63
64static inline void hibernate_restore_protect_page(void *page_address)
65{
66 if (hibernate_restore_protection_active)
67 set_memory_ro((unsigned long)page_address, 1);
68}
69
70static inline void hibernate_restore_unprotect_page(void *page_address)
71{
72 if (hibernate_restore_protection_active)
73 set_memory_rw((unsigned long)page_address, 1);
74}
75#else
76static inline void hibernate_restore_protection_begin(void) {}
77static inline void hibernate_restore_protection_end(void) {}
78static inline void hibernate_restore_protect_page(void *page_address) {}
79static inline void hibernate_restore_unprotect_page(void *page_address) {}
80#endif /* CONFIG_STRICT_KERNEL_RWX && CONFIG_ARCH_HAS_SET_MEMORY */
81
82static int swsusp_page_is_free(struct page *);
83static void swsusp_set_page_forbidden(struct page *);
84static void swsusp_unset_page_forbidden(struct page *);
85
86/*
87 * Number of bytes to reserve for memory allocations made by device drivers
88 * from their ->freeze() and ->freeze_noirq() callbacks so that they don't
89 * cause image creation to fail (tunable via /sys/power/reserved_size).
90 */
91unsigned long reserved_size;
92
93void __init hibernate_reserved_size_init(void)
94{
95 reserved_size = SPARE_PAGES * PAGE_SIZE;
96}
97
98/*
99 * Preferred image size in bytes (tunable via /sys/power/image_size).
100 * When it is set to N, swsusp will do its best to ensure the image
101 * size will not exceed N bytes, but if that is impossible, it will
102 * try to create the smallest image possible.
103 */
104unsigned long image_size;
105
106void __init hibernate_image_size_init(void)
107{
108 image_size = ((totalram_pages * 2) / 5) * PAGE_SIZE;
109}
110
111/*
112 * List of PBEs needed for restoring the pages that were allocated before
113 * the suspend and included in the suspend image, but have also been
114 * allocated by the "resume" kernel, so their contents cannot be written
115 * directly to their "original" page frames.
116 */
117struct pbe *restore_pblist;
118
119/* struct linked_page is used to build chains of pages */
120
121#define LINKED_PAGE_DATA_SIZE (PAGE_SIZE - sizeof(void *))
122
123struct linked_page {
124 struct linked_page *next;
125 char data[LINKED_PAGE_DATA_SIZE];
126} __packed;
127
128/*
129 * List of "safe" pages (ie. pages that were not used by the image kernel
130 * before hibernation) that may be used as temporary storage for image kernel
131 * memory contents.
132 */
133static struct linked_page *safe_pages_list;
134
135/* Pointer to an auxiliary buffer (1 page) */
136static void *buffer;
137
138#define PG_ANY 0
139#define PG_SAFE 1
140#define PG_UNSAFE_CLEAR 1
141#define PG_UNSAFE_KEEP 0
142
143static unsigned int allocated_unsafe_pages;
144
145/**
146 * get_image_page - Allocate a page for a hibernation image.
147 * @gfp_mask: GFP mask for the allocation.
148 * @safe_needed: Get pages that were not used before hibernation (restore only)
149 *
150 * During image restoration, for storing the PBE list and the image data, we can
151 * only use memory pages that do not conflict with the pages used before
152 * hibernation. The "unsafe" pages have PageNosaveFree set and we count them
153 * using allocated_unsafe_pages.
154 *
155 * Each allocated image page is marked as PageNosave and PageNosaveFree so that
156 * swsusp_free() can release it.
157 */
158static void *get_image_page(gfp_t gfp_mask, int safe_needed)
159{
160 void *res;
161
162 res = (void *)get_zeroed_page(gfp_mask);
163 if (safe_needed)
164 while (res && swsusp_page_is_free(virt_to_page(res))) {
165 /* The page is unsafe, mark it for swsusp_free() */
166 swsusp_set_page_forbidden(virt_to_page(res));
167 allocated_unsafe_pages++;
168 res = (void *)get_zeroed_page(gfp_mask);
169 }
170 if (res) {
171 swsusp_set_page_forbidden(virt_to_page(res));
172 swsusp_set_page_free(virt_to_page(res));
173 }
174 return res;
175}
176
177static void *__get_safe_page(gfp_t gfp_mask)
178{
179 if (safe_pages_list) {
180 void *ret = safe_pages_list;
181
182 safe_pages_list = safe_pages_list->next;
183 memset(ret, 0, PAGE_SIZE);
184 return ret;
185 }
186 return get_image_page(gfp_mask, PG_SAFE);
187}
188
189unsigned long get_safe_page(gfp_t gfp_mask)
190{
191 return (unsigned long)__get_safe_page(gfp_mask);
192}
193
194static struct page *alloc_image_page(gfp_t gfp_mask)
195{
196 struct page *page;
197
198 page = alloc_page(gfp_mask);
199 if (page) {
200 swsusp_set_page_forbidden(page);
201 swsusp_set_page_free(page);
202 }
203 return page;
204}
205
206static void recycle_safe_page(void *page_address)
207{
208 struct linked_page *lp = page_address;
209
210 lp->next = safe_pages_list;
211 safe_pages_list = lp;
212}
213
214/**
215 * free_image_page - Free a page allocated for hibernation image.
216 * @addr: Address of the page to free.
217 * @clear_nosave_free: If set, clear the PageNosaveFree bit for the page.
218 *
219 * The page to free should have been allocated by get_image_page() (page flags
220 * set by it are affected).
221 */
222static inline void free_image_page(void *addr, int clear_nosave_free)
223{
224 struct page *page;
225
226 BUG_ON(!virt_addr_valid(addr));
227
228 page = virt_to_page(addr);
229
230 swsusp_unset_page_forbidden(page);
231 if (clear_nosave_free)
232 swsusp_unset_page_free(page);
233
234 __free_page(page);
235}
236
237static inline void free_list_of_pages(struct linked_page *list,
238 int clear_page_nosave)
239{
240 while (list) {
241 struct linked_page *lp = list->next;
242
243 free_image_page(list, clear_page_nosave);
244 list = lp;
245 }
246}
247
248/*
249 * struct chain_allocator is used for allocating small objects out of
250 * a linked list of pages called 'the chain'.
251 *
252 * The chain grows each time when there is no room for a new object in
253 * the current page. The allocated objects cannot be freed individually.
254 * It is only possible to free them all at once, by freeing the entire
255 * chain.
256 *
257 * NOTE: The chain allocator may be inefficient if the allocated objects
258 * are not much smaller than PAGE_SIZE.
259 */
260struct chain_allocator {
261 struct linked_page *chain; /* the chain */
262 unsigned int used_space; /* total size of objects allocated out
263 of the current page */
264 gfp_t gfp_mask; /* mask for allocating pages */
265 int safe_needed; /* if set, only "safe" pages are allocated */
266};
267
268static void chain_init(struct chain_allocator *ca, gfp_t gfp_mask,
269 int safe_needed)
270{
271 ca->chain = NULL;
272 ca->used_space = LINKED_PAGE_DATA_SIZE;
273 ca->gfp_mask = gfp_mask;
274 ca->safe_needed = safe_needed;
275}
276
277static void *chain_alloc(struct chain_allocator *ca, unsigned int size)
278{
279 void *ret;
280
281 if (LINKED_PAGE_DATA_SIZE - ca->used_space < size) {
282 struct linked_page *lp;
283
284 lp = ca->safe_needed ? __get_safe_page(ca->gfp_mask) :
285 get_image_page(ca->gfp_mask, PG_ANY);
286 if (!lp)
287 return NULL;
288
289 lp->next = ca->chain;
290 ca->chain = lp;
291 ca->used_space = 0;
292 }
293 ret = ca->chain->data + ca->used_space;
294 ca->used_space += size;
295 return ret;
296}
297
298/**
299 * Data types related to memory bitmaps.
300 *
301 * Memory bitmap is a structure consiting of many linked lists of
302 * objects. The main list's elements are of type struct zone_bitmap
303 * and each of them corresonds to one zone. For each zone bitmap
304 * object there is a list of objects of type struct bm_block that
305 * represent each blocks of bitmap in which information is stored.
306 *
307 * struct memory_bitmap contains a pointer to the main list of zone
308 * bitmap objects, a struct bm_position used for browsing the bitmap,
309 * and a pointer to the list of pages used for allocating all of the
310 * zone bitmap objects and bitmap block objects.
311 *
312 * NOTE: It has to be possible to lay out the bitmap in memory
313 * using only allocations of order 0. Additionally, the bitmap is
314 * designed to work with arbitrary number of zones (this is over the
315 * top for now, but let's avoid making unnecessary assumptions ;-).
316 *
317 * struct zone_bitmap contains a pointer to a list of bitmap block
318 * objects and a pointer to the bitmap block object that has been
319 * most recently used for setting bits. Additionally, it contains the
320 * PFNs that correspond to the start and end of the represented zone.
321 *
322 * struct bm_block contains a pointer to the memory page in which
323 * information is stored (in the form of a block of bitmap)
324 * It also contains the pfns that correspond to the start and end of
325 * the represented memory area.
326 *
327 * The memory bitmap is organized as a radix tree to guarantee fast random
328 * access to the bits. There is one radix tree for each zone (as returned
329 * from create_mem_extents).
330 *
331 * One radix tree is represented by one struct mem_zone_bm_rtree. There are
332 * two linked lists for the nodes of the tree, one for the inner nodes and
333 * one for the leave nodes. The linked leave nodes are used for fast linear
334 * access of the memory bitmap.
335 *
336 * The struct rtree_node represents one node of the radix tree.
337 */
338
339#define BM_END_OF_MAP (~0UL)
340
341#define BM_BITS_PER_BLOCK (PAGE_SIZE * BITS_PER_BYTE)
342#define BM_BLOCK_SHIFT (PAGE_SHIFT + 3)
343#define BM_BLOCK_MASK ((1UL << BM_BLOCK_SHIFT) - 1)
344
345/*
346 * struct rtree_node is a wrapper struct to link the nodes
347 * of the rtree together for easy linear iteration over
348 * bits and easy freeing
349 */
350struct rtree_node {
351 struct list_head list;
352 unsigned long *data;
353};
354
355/*
356 * struct mem_zone_bm_rtree represents a bitmap used for one
357 * populated memory zone.
358 */
359struct mem_zone_bm_rtree {
360 struct list_head list; /* Link Zones together */
361 struct list_head nodes; /* Radix Tree inner nodes */
362 struct list_head leaves; /* Radix Tree leaves */
363 unsigned long start_pfn; /* Zone start page frame */
364 unsigned long end_pfn; /* Zone end page frame + 1 */
365 struct rtree_node *rtree; /* Radix Tree Root */
366 int levels; /* Number of Radix Tree Levels */
367 unsigned int blocks; /* Number of Bitmap Blocks */
368};
369
370/* strcut bm_position is used for browsing memory bitmaps */
371
372struct bm_position {
373 struct mem_zone_bm_rtree *zone;
374 struct rtree_node *node;
375 unsigned long node_pfn;
376 int node_bit;
377};
378
379struct memory_bitmap {
380 struct list_head zones;
381 struct linked_page *p_list; /* list of pages used to store zone
382 bitmap objects and bitmap block
383 objects */
384 struct bm_position cur; /* most recently used bit position */
385};
386
387/* Functions that operate on memory bitmaps */
388
389#define BM_ENTRIES_PER_LEVEL (PAGE_SIZE / sizeof(unsigned long))
390#if BITS_PER_LONG == 32
391#define BM_RTREE_LEVEL_SHIFT (PAGE_SHIFT - 2)
392#else
393#define BM_RTREE_LEVEL_SHIFT (PAGE_SHIFT - 3)
394#endif
395#define BM_RTREE_LEVEL_MASK ((1UL << BM_RTREE_LEVEL_SHIFT) - 1)
396
397/**
398 * alloc_rtree_node - Allocate a new node and add it to the radix tree.
399 *
400 * This function is used to allocate inner nodes as well as the
401 * leave nodes of the radix tree. It also adds the node to the
402 * corresponding linked list passed in by the *list parameter.
403 */
404static struct rtree_node *alloc_rtree_node(gfp_t gfp_mask, int safe_needed,
405 struct chain_allocator *ca,
406 struct list_head *list)
407{
408 struct rtree_node *node;
409
410 node = chain_alloc(ca, sizeof(struct rtree_node));
411 if (!node)
412 return NULL;
413
414 node->data = get_image_page(gfp_mask, safe_needed);
415 if (!node->data)
416 return NULL;
417
418 list_add_tail(&node->list, list);
419
420 return node;
421}
422
423/**
424 * add_rtree_block - Add a new leave node to the radix tree.
425 *
426 * The leave nodes need to be allocated in order to keep the leaves
427 * linked list in order. This is guaranteed by the zone->blocks
428 * counter.
429 */
430static int add_rtree_block(struct mem_zone_bm_rtree *zone, gfp_t gfp_mask,
431 int safe_needed, struct chain_allocator *ca)
432{
433 struct rtree_node *node, *block, **dst;
434 unsigned int levels_needed, block_nr;
435 int i;
436
437 block_nr = zone->blocks;
438 levels_needed = 0;
439
440 /* How many levels do we need for this block nr? */
441 while (block_nr) {
442 levels_needed += 1;
443 block_nr >>= BM_RTREE_LEVEL_SHIFT;
444 }
445
446 /* Make sure the rtree has enough levels */
447 for (i = zone->levels; i < levels_needed; i++) {
448 node = alloc_rtree_node(gfp_mask, safe_needed, ca,
449 &zone->nodes);
450 if (!node)
451 return -ENOMEM;
452
453 node->data[0] = (unsigned long)zone->rtree;
454 zone->rtree = node;
455 zone->levels += 1;
456 }
457
458 /* Allocate new block */
459 block = alloc_rtree_node(gfp_mask, safe_needed, ca, &zone->leaves);
460 if (!block)
461 return -ENOMEM;
462
463 /* Now walk the rtree to insert the block */
464 node = zone->rtree;
465 dst = &zone->rtree;
466 block_nr = zone->blocks;
467 for (i = zone->levels; i > 0; i--) {
468 int index;
469
470 if (!node) {
471 node = alloc_rtree_node(gfp_mask, safe_needed, ca,
472 &zone->nodes);
473 if (!node)
474 return -ENOMEM;
475 *dst = node;
476 }
477
478 index = block_nr >> ((i - 1) * BM_RTREE_LEVEL_SHIFT);
479 index &= BM_RTREE_LEVEL_MASK;
480 dst = (struct rtree_node **)&((*dst)->data[index]);
481 node = *dst;
482 }
483
484 zone->blocks += 1;
485 *dst = block;
486
487 return 0;
488}
489
490static void free_zone_bm_rtree(struct mem_zone_bm_rtree *zone,
491 int clear_nosave_free);
492
493/**
494 * create_zone_bm_rtree - Create a radix tree for one zone.
495 *
496 * Allocated the mem_zone_bm_rtree structure and initializes it.
497 * This function also allocated and builds the radix tree for the
498 * zone.
499 */
500static struct mem_zone_bm_rtree *create_zone_bm_rtree(gfp_t gfp_mask,
501 int safe_needed,
502 struct chain_allocator *ca,
503 unsigned long start,
504 unsigned long end)
505{
506 struct mem_zone_bm_rtree *zone;
507 unsigned int i, nr_blocks;
508 unsigned long pages;
509
510 pages = end - start;
511 zone = chain_alloc(ca, sizeof(struct mem_zone_bm_rtree));
512 if (!zone)
513 return NULL;
514
515 INIT_LIST_HEAD(&zone->nodes);
516 INIT_LIST_HEAD(&zone->leaves);
517 zone->start_pfn = start;
518 zone->end_pfn = end;
519 nr_blocks = DIV_ROUND_UP(pages, BM_BITS_PER_BLOCK);
520
521 for (i = 0; i < nr_blocks; i++) {
522 if (add_rtree_block(zone, gfp_mask, safe_needed, ca)) {
523 free_zone_bm_rtree(zone, PG_UNSAFE_CLEAR);
524 return NULL;
525 }
526 }
527
528 return zone;
529}
530
531/**
532 * free_zone_bm_rtree - Free the memory of the radix tree.
533 *
534 * Free all node pages of the radix tree. The mem_zone_bm_rtree
535 * structure itself is not freed here nor are the rtree_node
536 * structs.
537 */
538static void free_zone_bm_rtree(struct mem_zone_bm_rtree *zone,
539 int clear_nosave_free)
540{
541 struct rtree_node *node;
542
543 list_for_each_entry(node, &zone->nodes, list)
544 free_image_page(node->data, clear_nosave_free);
545
546 list_for_each_entry(node, &zone->leaves, list)
547 free_image_page(node->data, clear_nosave_free);
548}
549
550static void memory_bm_position_reset(struct memory_bitmap *bm)
551{
552 bm->cur.zone = list_entry(bm->zones.next, struct mem_zone_bm_rtree,
553 list);
554 bm->cur.node = list_entry(bm->cur.zone->leaves.next,
555 struct rtree_node, list);
556 bm->cur.node_pfn = 0;
557 bm->cur.node_bit = 0;
558}
559
560static void memory_bm_free(struct memory_bitmap *bm, int clear_nosave_free);
561
562struct mem_extent {
563 struct list_head hook;
564 unsigned long start;
565 unsigned long end;
566};
567
568/**
569 * free_mem_extents - Free a list of memory extents.
570 * @list: List of extents to free.
571 */
572static void free_mem_extents(struct list_head *list)
573{
574 struct mem_extent *ext, *aux;
575
576 list_for_each_entry_safe(ext, aux, list, hook) {
577 list_del(&ext->hook);
578 kfree(ext);
579 }
580}
581
582/**
583 * create_mem_extents - Create a list of memory extents.
584 * @list: List to put the extents into.
585 * @gfp_mask: Mask to use for memory allocations.
586 *
587 * The extents represent contiguous ranges of PFNs.
588 */
589static int create_mem_extents(struct list_head *list, gfp_t gfp_mask)
590{
591 struct zone *zone;
592
593 INIT_LIST_HEAD(list);
594
595 for_each_populated_zone(zone) {
596 unsigned long zone_start, zone_end;
597 struct mem_extent *ext, *cur, *aux;
598
599 zone_start = zone->zone_start_pfn;
600 zone_end = zone_end_pfn(zone);
601
602 list_for_each_entry(ext, list, hook)
603 if (zone_start <= ext->end)
604 break;
605
606 if (&ext->hook == list || zone_end < ext->start) {
607 /* New extent is necessary */
608 struct mem_extent *new_ext;
609
610 new_ext = kzalloc(sizeof(struct mem_extent), gfp_mask);
611 if (!new_ext) {
612 free_mem_extents(list);
613 return -ENOMEM;
614 }
615 new_ext->start = zone_start;
616 new_ext->end = zone_end;
617 list_add_tail(&new_ext->hook, &ext->hook);
618 continue;
619 }
620
621 /* Merge this zone's range of PFNs with the existing one */
622 if (zone_start < ext->start)
623 ext->start = zone_start;
624 if (zone_end > ext->end)
625 ext->end = zone_end;
626
627 /* More merging may be possible */
628 cur = ext;
629 list_for_each_entry_safe_continue(cur, aux, list, hook) {
630 if (zone_end < cur->start)
631 break;
632 if (zone_end < cur->end)
633 ext->end = cur->end;
634 list_del(&cur->hook);
635 kfree(cur);
636 }
637 }
638
639 return 0;
640}
641
642/**
643 * memory_bm_create - Allocate memory for a memory bitmap.
644 */
645static int memory_bm_create(struct memory_bitmap *bm, gfp_t gfp_mask,
646 int safe_needed)
647{
648 struct chain_allocator ca;
649 struct list_head mem_extents;
650 struct mem_extent *ext;
651 int error;
652
653 chain_init(&ca, gfp_mask, safe_needed);
654 INIT_LIST_HEAD(&bm->zones);
655
656 error = create_mem_extents(&mem_extents, gfp_mask);
657 if (error)
658 return error;
659
660 list_for_each_entry(ext, &mem_extents, hook) {
661 struct mem_zone_bm_rtree *zone;
662
663 zone = create_zone_bm_rtree(gfp_mask, safe_needed, &ca,
664 ext->start, ext->end);
665 if (!zone) {
666 error = -ENOMEM;
667 goto Error;
668 }
669 list_add_tail(&zone->list, &bm->zones);
670 }
671
672 bm->p_list = ca.chain;
673 memory_bm_position_reset(bm);
674 Exit:
675 free_mem_extents(&mem_extents);
676 return error;
677
678 Error:
679 bm->p_list = ca.chain;
680 memory_bm_free(bm, PG_UNSAFE_CLEAR);
681 goto Exit;
682}
683
684/**
685 * memory_bm_free - Free memory occupied by the memory bitmap.
686 * @bm: Memory bitmap.
687 */
688static void memory_bm_free(struct memory_bitmap *bm, int clear_nosave_free)
689{
690 struct mem_zone_bm_rtree *zone;
691
692 list_for_each_entry(zone, &bm->zones, list)
693 free_zone_bm_rtree(zone, clear_nosave_free);
694
695 free_list_of_pages(bm->p_list, clear_nosave_free);
696
697 INIT_LIST_HEAD(&bm->zones);
698}
699
700/**
701 * memory_bm_find_bit - Find the bit for a given PFN in a memory bitmap.
702 *
703 * Find the bit in memory bitmap @bm that corresponds to the given PFN.
704 * The cur.zone, cur.block and cur.node_pfn members of @bm are updated.
705 *
706 * Walk the radix tree to find the page containing the bit that represents @pfn
707 * and return the position of the bit in @addr and @bit_nr.
708 */
709static int memory_bm_find_bit(struct memory_bitmap *bm, unsigned long pfn,
710 void **addr, unsigned int *bit_nr)
711{
712 struct mem_zone_bm_rtree *curr, *zone;
713 struct rtree_node *node;
714 int i, block_nr;
715
716 zone = bm->cur.zone;
717
718 if (pfn >= zone->start_pfn && pfn < zone->end_pfn)
719 goto zone_found;
720
721 zone = NULL;
722
723 /* Find the right zone */
724 list_for_each_entry(curr, &bm->zones, list) {
725 if (pfn >= curr->start_pfn && pfn < curr->end_pfn) {
726 zone = curr;
727 break;
728 }
729 }
730
731 if (!zone)
732 return -EFAULT;
733
734zone_found:
735 /*
736 * We have found the zone. Now walk the radix tree to find the leaf node
737 * for our PFN.
738 */
739 node = bm->cur.node;
740 if (((pfn - zone->start_pfn) & ~BM_BLOCK_MASK) == bm->cur.node_pfn)
741 goto node_found;
742
743 node = zone->rtree;
744 block_nr = (pfn - zone->start_pfn) >> BM_BLOCK_SHIFT;
745
746 for (i = zone->levels; i > 0; i--) {
747 int index;
748
749 index = block_nr >> ((i - 1) * BM_RTREE_LEVEL_SHIFT);
750 index &= BM_RTREE_LEVEL_MASK;
751 BUG_ON(node->data[index] == 0);
752 node = (struct rtree_node *)node->data[index];
753 }
754
755node_found:
756 /* Update last position */
757 bm->cur.zone = zone;
758 bm->cur.node = node;
759 bm->cur.node_pfn = (pfn - zone->start_pfn) & ~BM_BLOCK_MASK;
760
761 /* Set return values */
762 *addr = node->data;
763 *bit_nr = (pfn - zone->start_pfn) & BM_BLOCK_MASK;
764
765 return 0;
766}
767
768static void memory_bm_set_bit(struct memory_bitmap *bm, unsigned long pfn)
769{
770 void *addr;
771 unsigned int bit;
772 int error;
773
774 error = memory_bm_find_bit(bm, pfn, &addr, &bit);
775 BUG_ON(error);
776 set_bit(bit, addr);
777}
778
779static int mem_bm_set_bit_check(struct memory_bitmap *bm, unsigned long pfn)
780{
781 void *addr;
782 unsigned int bit;
783 int error;
784
785 error = memory_bm_find_bit(bm, pfn, &addr, &bit);
786 if (!error)
787 set_bit(bit, addr);
788
789 return error;
790}
791
792static void memory_bm_clear_bit(struct memory_bitmap *bm, unsigned long pfn)
793{
794 void *addr;
795 unsigned int bit;
796 int error;
797
798 error = memory_bm_find_bit(bm, pfn, &addr, &bit);
799 BUG_ON(error);
800 clear_bit(bit, addr);
801}
802
803static void memory_bm_clear_current(struct memory_bitmap *bm)
804{
805 int bit;
806
807 bit = max(bm->cur.node_bit - 1, 0);
808 clear_bit(bit, bm->cur.node->data);
809}
810
811static int memory_bm_test_bit(struct memory_bitmap *bm, unsigned long pfn)
812{
813 void *addr;
814 unsigned int bit;
815 int error;
816
817 error = memory_bm_find_bit(bm, pfn, &addr, &bit);
818 BUG_ON(error);
819 return test_bit(bit, addr);
820}
821
822static bool memory_bm_pfn_present(struct memory_bitmap *bm, unsigned long pfn)
823{
824 void *addr;
825 unsigned int bit;
826
827 return !memory_bm_find_bit(bm, pfn, &addr, &bit);
828}
829
830/*
831 * rtree_next_node - Jump to the next leaf node.
832 *
833 * Set the position to the beginning of the next node in the
834 * memory bitmap. This is either the next node in the current
835 * zone's radix tree or the first node in the radix tree of the
836 * next zone.
837 *
838 * Return true if there is a next node, false otherwise.
839 */
840static bool rtree_next_node(struct memory_bitmap *bm)
841{
842 if (!list_is_last(&bm->cur.node->list, &bm->cur.zone->leaves)) {
843 bm->cur.node = list_entry(bm->cur.node->list.next,
844 struct rtree_node, list);
845 bm->cur.node_pfn += BM_BITS_PER_BLOCK;
846 bm->cur.node_bit = 0;
847 touch_softlockup_watchdog();
848 return true;
849 }
850
851 /* No more nodes, goto next zone */
852 if (!list_is_last(&bm->cur.zone->list, &bm->zones)) {
853 bm->cur.zone = list_entry(bm->cur.zone->list.next,
854 struct mem_zone_bm_rtree, list);
855 bm->cur.node = list_entry(bm->cur.zone->leaves.next,
856 struct rtree_node, list);
857 bm->cur.node_pfn = 0;
858 bm->cur.node_bit = 0;
859 return true;
860 }
861
862 /* No more zones */
863 return false;
864}
865
866/**
867 * memory_bm_rtree_next_pfn - Find the next set bit in a memory bitmap.
868 * @bm: Memory bitmap.
869 *
870 * Starting from the last returned position this function searches for the next
871 * set bit in @bm and returns the PFN represented by it. If no more bits are
872 * set, BM_END_OF_MAP is returned.
873 *
874 * It is required to run memory_bm_position_reset() before the first call to
875 * this function for the given memory bitmap.
876 */
877static unsigned long memory_bm_next_pfn(struct memory_bitmap *bm)
878{
879 unsigned long bits, pfn, pages;
880 int bit;
881
882 do {
883 pages = bm->cur.zone->end_pfn - bm->cur.zone->start_pfn;
884 bits = min(pages - bm->cur.node_pfn, BM_BITS_PER_BLOCK);
885 bit = find_next_bit(bm->cur.node->data, bits,
886 bm->cur.node_bit);
887 if (bit < bits) {
888 pfn = bm->cur.zone->start_pfn + bm->cur.node_pfn + bit;
889 bm->cur.node_bit = bit + 1;
890 return pfn;
891 }
892 } while (rtree_next_node(bm));
893
894 return BM_END_OF_MAP;
895}
896
897/*
898 * This structure represents a range of page frames the contents of which
899 * should not be saved during hibernation.
900 */
901struct nosave_region {
902 struct list_head list;
903 unsigned long start_pfn;
904 unsigned long end_pfn;
905};
906
907static LIST_HEAD(nosave_regions);
908
909static void recycle_zone_bm_rtree(struct mem_zone_bm_rtree *zone)
910{
911 struct rtree_node *node;
912
913 list_for_each_entry(node, &zone->nodes, list)
914 recycle_safe_page(node->data);
915
916 list_for_each_entry(node, &zone->leaves, list)
917 recycle_safe_page(node->data);
918}
919
920static void memory_bm_recycle(struct memory_bitmap *bm)
921{
922 struct mem_zone_bm_rtree *zone;
923 struct linked_page *p_list;
924
925 list_for_each_entry(zone, &bm->zones, list)
926 recycle_zone_bm_rtree(zone);
927
928 p_list = bm->p_list;
929 while (p_list) {
930 struct linked_page *lp = p_list;
931
932 p_list = lp->next;
933 recycle_safe_page(lp);
934 }
935}
936
937/**
938 * register_nosave_region - Register a region of unsaveable memory.
939 *
940 * Register a range of page frames the contents of which should not be saved
941 * during hibernation (to be used in the early initialization code).
942 */
943void __init __register_nosave_region(unsigned long start_pfn,
944 unsigned long end_pfn, int use_kmalloc)
945{
946 struct nosave_region *region;
947
948 if (start_pfn >= end_pfn)
949 return;
950
951 if (!list_empty(&nosave_regions)) {
952 /* Try to extend the previous region (they should be sorted) */
953 region = list_entry(nosave_regions.prev,
954 struct nosave_region, list);
955 if (region->end_pfn == start_pfn) {
956 region->end_pfn = end_pfn;
957 goto Report;
958 }
959 }
960 if (use_kmalloc) {
961 /* During init, this shouldn't fail */
962 region = kmalloc(sizeof(struct nosave_region), GFP_KERNEL);
963 BUG_ON(!region);
964 } else {
965 /* This allocation cannot fail */
966 region = memblock_virt_alloc(sizeof(struct nosave_region), 0);
967 }
968 region->start_pfn = start_pfn;
969 region->end_pfn = end_pfn;
970 list_add_tail(®ion->list, &nosave_regions);
971 Report:
972 pr_info("Registered nosave memory: [mem %#010llx-%#010llx]\n",
973 (unsigned long long) start_pfn << PAGE_SHIFT,
974 ((unsigned long long) end_pfn << PAGE_SHIFT) - 1);
975}
976
977/*
978 * Set bits in this map correspond to the page frames the contents of which
979 * should not be saved during the suspend.
980 */
981static struct memory_bitmap *forbidden_pages_map;
982
983/* Set bits in this map correspond to free page frames. */
984static struct memory_bitmap *free_pages_map;
985
986/*
987 * Each page frame allocated for creating the image is marked by setting the
988 * corresponding bits in forbidden_pages_map and free_pages_map simultaneously
989 */
990
991void swsusp_set_page_free(struct page *page)
992{
993 if (free_pages_map)
994 memory_bm_set_bit(free_pages_map, page_to_pfn(page));
995}
996
997static int swsusp_page_is_free(struct page *page)
998{
999 return free_pages_map ?
1000 memory_bm_test_bit(free_pages_map, page_to_pfn(page)) : 0;
1001}
1002
1003void swsusp_unset_page_free(struct page *page)
1004{
1005 if (free_pages_map)
1006 memory_bm_clear_bit(free_pages_map, page_to_pfn(page));
1007}
1008
1009static void swsusp_set_page_forbidden(struct page *page)
1010{
1011 if (forbidden_pages_map)
1012 memory_bm_set_bit(forbidden_pages_map, page_to_pfn(page));
1013}
1014
1015int swsusp_page_is_forbidden(struct page *page)
1016{
1017 return forbidden_pages_map ?
1018 memory_bm_test_bit(forbidden_pages_map, page_to_pfn(page)) : 0;
1019}
1020
1021static void swsusp_unset_page_forbidden(struct page *page)
1022{
1023 if (forbidden_pages_map)
1024 memory_bm_clear_bit(forbidden_pages_map, page_to_pfn(page));
1025}
1026
1027/**
1028 * mark_nosave_pages - Mark pages that should not be saved.
1029 * @bm: Memory bitmap.
1030 *
1031 * Set the bits in @bm that correspond to the page frames the contents of which
1032 * should not be saved.
1033 */
1034static void mark_nosave_pages(struct memory_bitmap *bm)
1035{
1036 struct nosave_region *region;
1037
1038 if (list_empty(&nosave_regions))
1039 return;
1040
1041 list_for_each_entry(region, &nosave_regions, list) {
1042 unsigned long pfn;
1043
1044 pr_debug("Marking nosave pages: [mem %#010llx-%#010llx]\n",
1045 (unsigned long long) region->start_pfn << PAGE_SHIFT,
1046 ((unsigned long long) region->end_pfn << PAGE_SHIFT)
1047 - 1);
1048
1049 for (pfn = region->start_pfn; pfn < region->end_pfn; pfn++)
1050 if (pfn_valid(pfn)) {
1051 /*
1052 * It is safe to ignore the result of
1053 * mem_bm_set_bit_check() here, since we won't
1054 * touch the PFNs for which the error is
1055 * returned anyway.
1056 */
1057 mem_bm_set_bit_check(bm, pfn);
1058 }
1059 }
1060}
1061
1062/**
1063 * create_basic_memory_bitmaps - Create bitmaps to hold basic page information.
1064 *
1065 * Create bitmaps needed for marking page frames that should not be saved and
1066 * free page frames. The forbidden_pages_map and free_pages_map pointers are
1067 * only modified if everything goes well, because we don't want the bits to be
1068 * touched before both bitmaps are set up.
1069 */
1070int create_basic_memory_bitmaps(void)
1071{
1072 struct memory_bitmap *bm1, *bm2;
1073 int error = 0;
1074
1075 if (forbidden_pages_map && free_pages_map)
1076 return 0;
1077 else
1078 BUG_ON(forbidden_pages_map || free_pages_map);
1079
1080 bm1 = kzalloc(sizeof(struct memory_bitmap), GFP_KERNEL);
1081 if (!bm1)
1082 return -ENOMEM;
1083
1084 error = memory_bm_create(bm1, GFP_KERNEL, PG_ANY);
1085 if (error)
1086 goto Free_first_object;
1087
1088 bm2 = kzalloc(sizeof(struct memory_bitmap), GFP_KERNEL);
1089 if (!bm2)
1090 goto Free_first_bitmap;
1091
1092 error = memory_bm_create(bm2, GFP_KERNEL, PG_ANY);
1093 if (error)
1094 goto Free_second_object;
1095
1096 forbidden_pages_map = bm1;
1097 free_pages_map = bm2;
1098 mark_nosave_pages(forbidden_pages_map);
1099
1100 pr_debug("Basic memory bitmaps created\n");
1101
1102 return 0;
1103
1104 Free_second_object:
1105 kfree(bm2);
1106 Free_first_bitmap:
1107 memory_bm_free(bm1, PG_UNSAFE_CLEAR);
1108 Free_first_object:
1109 kfree(bm1);
1110 return -ENOMEM;
1111}
1112
1113/**
1114 * free_basic_memory_bitmaps - Free memory bitmaps holding basic information.
1115 *
1116 * Free memory bitmaps allocated by create_basic_memory_bitmaps(). The
1117 * auxiliary pointers are necessary so that the bitmaps themselves are not
1118 * referred to while they are being freed.
1119 */
1120void free_basic_memory_bitmaps(void)
1121{
1122 struct memory_bitmap *bm1, *bm2;
1123
1124 if (WARN_ON(!(forbidden_pages_map && free_pages_map)))
1125 return;
1126
1127 bm1 = forbidden_pages_map;
1128 bm2 = free_pages_map;
1129 forbidden_pages_map = NULL;
1130 free_pages_map = NULL;
1131 memory_bm_free(bm1, PG_UNSAFE_CLEAR);
1132 kfree(bm1);
1133 memory_bm_free(bm2, PG_UNSAFE_CLEAR);
1134 kfree(bm2);
1135
1136 pr_debug("Basic memory bitmaps freed\n");
1137}
1138
1139void clear_free_pages(void)
1140{
1141#ifdef CONFIG_PAGE_POISONING_ZERO
1142 struct memory_bitmap *bm = free_pages_map;
1143 unsigned long pfn;
1144
1145 if (WARN_ON(!(free_pages_map)))
1146 return;
1147
1148 memory_bm_position_reset(bm);
1149 pfn = memory_bm_next_pfn(bm);
1150 while (pfn != BM_END_OF_MAP) {
1151 if (pfn_valid(pfn))
1152 clear_highpage(pfn_to_page(pfn));
1153
1154 pfn = memory_bm_next_pfn(bm);
1155 }
1156 memory_bm_position_reset(bm);
1157 pr_info("free pages cleared after restore\n");
1158#endif /* PAGE_POISONING_ZERO */
1159}
1160
1161/**
1162 * snapshot_additional_pages - Estimate the number of extra pages needed.
1163 * @zone: Memory zone to carry out the computation for.
1164 *
1165 * Estimate the number of additional pages needed for setting up a hibernation
1166 * image data structures for @zone (usually, the returned value is greater than
1167 * the exact number).
1168 */
1169unsigned int snapshot_additional_pages(struct zone *zone)
1170{
1171 unsigned int rtree, nodes;
1172
1173 rtree = nodes = DIV_ROUND_UP(zone->spanned_pages, BM_BITS_PER_BLOCK);
1174 rtree += DIV_ROUND_UP(rtree * sizeof(struct rtree_node),
1175 LINKED_PAGE_DATA_SIZE);
1176 while (nodes > 1) {
1177 nodes = DIV_ROUND_UP(nodes, BM_ENTRIES_PER_LEVEL);
1178 rtree += nodes;
1179 }
1180
1181 return 2 * rtree;
1182}
1183
1184#ifdef CONFIG_HIGHMEM
1185/**
1186 * count_free_highmem_pages - Compute the total number of free highmem pages.
1187 *
1188 * The returned number is system-wide.
1189 */
1190static unsigned int count_free_highmem_pages(void)
1191{
1192 struct zone *zone;
1193 unsigned int cnt = 0;
1194
1195 for_each_populated_zone(zone)
1196 if (is_highmem(zone))
1197 cnt += zone_page_state(zone, NR_FREE_PAGES);
1198
1199 return cnt;
1200}
1201
1202/**
1203 * saveable_highmem_page - Check if a highmem page is saveable.
1204 *
1205 * Determine whether a highmem page should be included in a hibernation image.
1206 *
1207 * We should save the page if it isn't Nosave or NosaveFree, or Reserved,
1208 * and it isn't part of a free chunk of pages.
1209 */
1210static struct page *saveable_highmem_page(struct zone *zone, unsigned long pfn)
1211{
1212 struct page *page;
1213
1214 if (!pfn_valid(pfn))
1215 return NULL;
1216
1217 page = pfn_to_page(pfn);
1218 if (page_zone(page) != zone)
1219 return NULL;
1220
1221 BUG_ON(!PageHighMem(page));
1222
1223 if (swsusp_page_is_forbidden(page) || swsusp_page_is_free(page) ||
1224 PageReserved(page))
1225 return NULL;
1226
1227 if (page_is_guard(page))
1228 return NULL;
1229
1230 return page;
1231}
1232
1233/**
1234 * count_highmem_pages - Compute the total number of saveable highmem pages.
1235 */
1236static unsigned int count_highmem_pages(void)
1237{
1238 struct zone *zone;
1239 unsigned int n = 0;
1240
1241 for_each_populated_zone(zone) {
1242 unsigned long pfn, max_zone_pfn;
1243
1244 if (!is_highmem(zone))
1245 continue;
1246
1247 mark_free_pages(zone);
1248 max_zone_pfn = zone_end_pfn(zone);
1249 for (pfn = zone->zone_start_pfn; pfn < max_zone_pfn; pfn++)
1250 if (saveable_highmem_page(zone, pfn))
1251 n++;
1252 }
1253 return n;
1254}
1255#else
1256static inline void *saveable_highmem_page(struct zone *z, unsigned long p)
1257{
1258 return NULL;
1259}
1260#endif /* CONFIG_HIGHMEM */
1261
1262/**
1263 * saveable_page - Check if the given page is saveable.
1264 *
1265 * Determine whether a non-highmem page should be included in a hibernation
1266 * image.
1267 *
1268 * We should save the page if it isn't Nosave, and is not in the range
1269 * of pages statically defined as 'unsaveable', and it isn't part of
1270 * a free chunk of pages.
1271 */
1272static struct page *saveable_page(struct zone *zone, unsigned long pfn)
1273{
1274 struct page *page;
1275
1276 if (!pfn_valid(pfn))
1277 return NULL;
1278
1279 page = pfn_to_page(pfn);
1280 if (page_zone(page) != zone)
1281 return NULL;
1282
1283 BUG_ON(PageHighMem(page));
1284
1285 if (swsusp_page_is_forbidden(page) || swsusp_page_is_free(page))
1286 return NULL;
1287
1288 if (PageReserved(page)
1289 && (!kernel_page_present(page) || pfn_is_nosave(pfn)))
1290 return NULL;
1291
1292 if (page_is_guard(page))
1293 return NULL;
1294
1295 return page;
1296}
1297
1298/**
1299 * count_data_pages - Compute the total number of saveable non-highmem pages.
1300 */
1301static unsigned int count_data_pages(void)
1302{
1303 struct zone *zone;
1304 unsigned long pfn, max_zone_pfn;
1305 unsigned int n = 0;
1306
1307 for_each_populated_zone(zone) {
1308 if (is_highmem(zone))
1309 continue;
1310
1311 mark_free_pages(zone);
1312 max_zone_pfn = zone_end_pfn(zone);
1313 for (pfn = zone->zone_start_pfn; pfn < max_zone_pfn; pfn++)
1314 if (saveable_page(zone, pfn))
1315 n++;
1316 }
1317 return n;
1318}
1319
1320/*
1321 * This is needed, because copy_page and memcpy are not usable for copying
1322 * task structs.
1323 */
1324static inline void do_copy_page(long *dst, long *src)
1325{
1326 int n;
1327
1328 for (n = PAGE_SIZE / sizeof(long); n; n--)
1329 *dst++ = *src++;
1330}
1331
1332/**
1333 * safe_copy_page - Copy a page in a safe way.
1334 *
1335 * Check if the page we are going to copy is marked as present in the kernel
1336 * page tables (this always is the case if CONFIG_DEBUG_PAGEALLOC is not set
1337 * and in that case kernel_page_present() always returns 'true').
1338 */
1339static void safe_copy_page(void *dst, struct page *s_page)
1340{
1341 if (kernel_page_present(s_page)) {
1342 do_copy_page(dst, page_address(s_page));
1343 } else {
1344 kernel_map_pages(s_page, 1, 1);
1345 do_copy_page(dst, page_address(s_page));
1346 kernel_map_pages(s_page, 1, 0);
1347 }
1348}
1349
1350#ifdef CONFIG_HIGHMEM
1351static inline struct page *page_is_saveable(struct zone *zone, unsigned long pfn)
1352{
1353 return is_highmem(zone) ?
1354 saveable_highmem_page(zone, pfn) : saveable_page(zone, pfn);
1355}
1356
1357static void copy_data_page(unsigned long dst_pfn, unsigned long src_pfn)
1358{
1359 struct page *s_page, *d_page;
1360 void *src, *dst;
1361
1362 s_page = pfn_to_page(src_pfn);
1363 d_page = pfn_to_page(dst_pfn);
1364 if (PageHighMem(s_page)) {
1365 src = kmap_atomic(s_page);
1366 dst = kmap_atomic(d_page);
1367 do_copy_page(dst, src);
1368 kunmap_atomic(dst);
1369 kunmap_atomic(src);
1370 } else {
1371 if (PageHighMem(d_page)) {
1372 /*
1373 * The page pointed to by src may contain some kernel
1374 * data modified by kmap_atomic()
1375 */
1376 safe_copy_page(buffer, s_page);
1377 dst = kmap_atomic(d_page);
1378 copy_page(dst, buffer);
1379 kunmap_atomic(dst);
1380 } else {
1381 safe_copy_page(page_address(d_page), s_page);
1382 }
1383 }
1384}
1385#else
1386#define page_is_saveable(zone, pfn) saveable_page(zone, pfn)
1387
1388static inline void copy_data_page(unsigned long dst_pfn, unsigned long src_pfn)
1389{
1390 safe_copy_page(page_address(pfn_to_page(dst_pfn)),
1391 pfn_to_page(src_pfn));
1392}
1393#endif /* CONFIG_HIGHMEM */
1394
1395static void copy_data_pages(struct memory_bitmap *copy_bm,
1396 struct memory_bitmap *orig_bm)
1397{
1398 struct zone *zone;
1399 unsigned long pfn;
1400
1401 for_each_populated_zone(zone) {
1402 unsigned long max_zone_pfn;
1403
1404 mark_free_pages(zone);
1405 max_zone_pfn = zone_end_pfn(zone);
1406 for (pfn = zone->zone_start_pfn; pfn < max_zone_pfn; pfn++)
1407 if (page_is_saveable(zone, pfn))
1408 memory_bm_set_bit(orig_bm, pfn);
1409 }
1410 memory_bm_position_reset(orig_bm);
1411 memory_bm_position_reset(copy_bm);
1412 for(;;) {
1413 pfn = memory_bm_next_pfn(orig_bm);
1414 if (unlikely(pfn == BM_END_OF_MAP))
1415 break;
1416 copy_data_page(memory_bm_next_pfn(copy_bm), pfn);
1417 }
1418}
1419
1420/* Total number of image pages */
1421static unsigned int nr_copy_pages;
1422/* Number of pages needed for saving the original pfns of the image pages */
1423static unsigned int nr_meta_pages;
1424/*
1425 * Numbers of normal and highmem page frames allocated for hibernation image
1426 * before suspending devices.
1427 */
1428static unsigned int alloc_normal, alloc_highmem;
1429/*
1430 * Memory bitmap used for marking saveable pages (during hibernation) or
1431 * hibernation image pages (during restore)
1432 */
1433static struct memory_bitmap orig_bm;
1434/*
1435 * Memory bitmap used during hibernation for marking allocated page frames that
1436 * will contain copies of saveable pages. During restore it is initially used
1437 * for marking hibernation image pages, but then the set bits from it are
1438 * duplicated in @orig_bm and it is released. On highmem systems it is next
1439 * used for marking "safe" highmem pages, but it has to be reinitialized for
1440 * this purpose.
1441 */
1442static struct memory_bitmap copy_bm;
1443
1444/**
1445 * swsusp_free - Free pages allocated for hibernation image.
1446 *
1447 * Image pages are alocated before snapshot creation, so they need to be
1448 * released after resume.
1449 */
1450void swsusp_free(void)
1451{
1452 unsigned long fb_pfn, fr_pfn;
1453
1454 if (!forbidden_pages_map || !free_pages_map)
1455 goto out;
1456
1457 memory_bm_position_reset(forbidden_pages_map);
1458 memory_bm_position_reset(free_pages_map);
1459
1460loop:
1461 fr_pfn = memory_bm_next_pfn(free_pages_map);
1462 fb_pfn = memory_bm_next_pfn(forbidden_pages_map);
1463
1464 /*
1465 * Find the next bit set in both bitmaps. This is guaranteed to
1466 * terminate when fb_pfn == fr_pfn == BM_END_OF_MAP.
1467 */
1468 do {
1469 if (fb_pfn < fr_pfn)
1470 fb_pfn = memory_bm_next_pfn(forbidden_pages_map);
1471 if (fr_pfn < fb_pfn)
1472 fr_pfn = memory_bm_next_pfn(free_pages_map);
1473 } while (fb_pfn != fr_pfn);
1474
1475 if (fr_pfn != BM_END_OF_MAP && pfn_valid(fr_pfn)) {
1476 struct page *page = pfn_to_page(fr_pfn);
1477
1478 memory_bm_clear_current(forbidden_pages_map);
1479 memory_bm_clear_current(free_pages_map);
1480 hibernate_restore_unprotect_page(page_address(page));
1481 __free_page(page);
1482 goto loop;
1483 }
1484
1485out:
1486 nr_copy_pages = 0;
1487 nr_meta_pages = 0;
1488 restore_pblist = NULL;
1489 buffer = NULL;
1490 alloc_normal = 0;
1491 alloc_highmem = 0;
1492 hibernate_restore_protection_end();
1493}
1494
1495/* Helper functions used for the shrinking of memory. */
1496
1497#define GFP_IMAGE (GFP_KERNEL | __GFP_NOWARN)
1498
1499/**
1500 * preallocate_image_pages - Allocate a number of pages for hibernation image.
1501 * @nr_pages: Number of page frames to allocate.
1502 * @mask: GFP flags to use for the allocation.
1503 *
1504 * Return value: Number of page frames actually allocated
1505 */
1506static unsigned long preallocate_image_pages(unsigned long nr_pages, gfp_t mask)
1507{
1508 unsigned long nr_alloc = 0;
1509
1510 while (nr_pages > 0) {
1511 struct page *page;
1512
1513 page = alloc_image_page(mask);
1514 if (!page)
1515 break;
1516 memory_bm_set_bit(©_bm, page_to_pfn(page));
1517 if (PageHighMem(page))
1518 alloc_highmem++;
1519 else
1520 alloc_normal++;
1521 nr_pages--;
1522 nr_alloc++;
1523 }
1524
1525 return nr_alloc;
1526}
1527
1528static unsigned long preallocate_image_memory(unsigned long nr_pages,
1529 unsigned long avail_normal)
1530{
1531 unsigned long alloc;
1532
1533 if (avail_normal <= alloc_normal)
1534 return 0;
1535
1536 alloc = avail_normal - alloc_normal;
1537 if (nr_pages < alloc)
1538 alloc = nr_pages;
1539
1540 return preallocate_image_pages(alloc, GFP_IMAGE);
1541}
1542
1543#ifdef CONFIG_HIGHMEM
1544static unsigned long preallocate_image_highmem(unsigned long nr_pages)
1545{
1546 return preallocate_image_pages(nr_pages, GFP_IMAGE | __GFP_HIGHMEM);
1547}
1548
1549/**
1550 * __fraction - Compute (an approximation of) x * (multiplier / base).
1551 */
1552static unsigned long __fraction(u64 x, u64 multiplier, u64 base)
1553{
1554 x *= multiplier;
1555 do_div(x, base);
1556 return (unsigned long)x;
1557}
1558
1559static unsigned long preallocate_highmem_fraction(unsigned long nr_pages,
1560 unsigned long highmem,
1561 unsigned long total)
1562{
1563 unsigned long alloc = __fraction(nr_pages, highmem, total);
1564
1565 return preallocate_image_pages(alloc, GFP_IMAGE | __GFP_HIGHMEM);
1566}
1567#else /* CONFIG_HIGHMEM */
1568static inline unsigned long preallocate_image_highmem(unsigned long nr_pages)
1569{
1570 return 0;
1571}
1572
1573static inline unsigned long preallocate_highmem_fraction(unsigned long nr_pages,
1574 unsigned long highmem,
1575 unsigned long total)
1576{
1577 return 0;
1578}
1579#endif /* CONFIG_HIGHMEM */
1580
1581/**
1582 * free_unnecessary_pages - Release preallocated pages not needed for the image.
1583 */
1584static unsigned long free_unnecessary_pages(void)
1585{
1586 unsigned long save, to_free_normal, to_free_highmem, free;
1587
1588 save = count_data_pages();
1589 if (alloc_normal >= save) {
1590 to_free_normal = alloc_normal - save;
1591 save = 0;
1592 } else {
1593 to_free_normal = 0;
1594 save -= alloc_normal;
1595 }
1596 save += count_highmem_pages();
1597 if (alloc_highmem >= save) {
1598 to_free_highmem = alloc_highmem - save;
1599 } else {
1600 to_free_highmem = 0;
1601 save -= alloc_highmem;
1602 if (to_free_normal > save)
1603 to_free_normal -= save;
1604 else
1605 to_free_normal = 0;
1606 }
1607 free = to_free_normal + to_free_highmem;
1608
1609 memory_bm_position_reset(©_bm);
1610
1611 while (to_free_normal > 0 || to_free_highmem > 0) {
1612 unsigned long pfn = memory_bm_next_pfn(©_bm);
1613 struct page *page = pfn_to_page(pfn);
1614
1615 if (PageHighMem(page)) {
1616 if (!to_free_highmem)
1617 continue;
1618 to_free_highmem--;
1619 alloc_highmem--;
1620 } else {
1621 if (!to_free_normal)
1622 continue;
1623 to_free_normal--;
1624 alloc_normal--;
1625 }
1626 memory_bm_clear_bit(©_bm, pfn);
1627 swsusp_unset_page_forbidden(page);
1628 swsusp_unset_page_free(page);
1629 __free_page(page);
1630 }
1631
1632 return free;
1633}
1634
1635/**
1636 * minimum_image_size - Estimate the minimum acceptable size of an image.
1637 * @saveable: Number of saveable pages in the system.
1638 *
1639 * We want to avoid attempting to free too much memory too hard, so estimate the
1640 * minimum acceptable size of a hibernation image to use as the lower limit for
1641 * preallocating memory.
1642 *
1643 * We assume that the minimum image size should be proportional to
1644 *
1645 * [number of saveable pages] - [number of pages that can be freed in theory]
1646 *
1647 * where the second term is the sum of (1) reclaimable slab pages, (2) active
1648 * and (3) inactive anonymous pages, (4) active and (5) inactive file pages.
1649 */
1650static unsigned long minimum_image_size(unsigned long saveable)
1651{
1652 unsigned long size;
1653
1654 size = global_node_page_state(NR_SLAB_RECLAIMABLE)
1655 + global_node_page_state(NR_ACTIVE_ANON)
1656 + global_node_page_state(NR_INACTIVE_ANON)
1657 + global_node_page_state(NR_ACTIVE_FILE)
1658 + global_node_page_state(NR_INACTIVE_FILE);
1659
1660 return saveable <= size ? 0 : saveable - size;
1661}
1662
1663/**
1664 * hibernate_preallocate_memory - Preallocate memory for hibernation image.
1665 *
1666 * To create a hibernation image it is necessary to make a copy of every page
1667 * frame in use. We also need a number of page frames to be free during
1668 * hibernation for allocations made while saving the image and for device
1669 * drivers, in case they need to allocate memory from their hibernation
1670 * callbacks (these two numbers are given by PAGES_FOR_IO (which is a rough
1671 * estimate) and reserverd_size divided by PAGE_SIZE (which is tunable through
1672 * /sys/power/reserved_size, respectively). To make this happen, we compute the
1673 * total number of available page frames and allocate at least
1674 *
1675 * ([page frames total] + PAGES_FOR_IO + [metadata pages]) / 2
1676 * + 2 * DIV_ROUND_UP(reserved_size, PAGE_SIZE)
1677 *
1678 * of them, which corresponds to the maximum size of a hibernation image.
1679 *
1680 * If image_size is set below the number following from the above formula,
1681 * the preallocation of memory is continued until the total number of saveable
1682 * pages in the system is below the requested image size or the minimum
1683 * acceptable image size returned by minimum_image_size(), whichever is greater.
1684 */
1685int hibernate_preallocate_memory(void)
1686{
1687 struct zone *zone;
1688 unsigned long saveable, size, max_size, count, highmem, pages = 0;
1689 unsigned long alloc, save_highmem, pages_highmem, avail_normal;
1690 ktime_t start, stop;
1691 int error;
1692
1693 pr_info("Preallocating image memory... ");
1694 start = ktime_get();
1695
1696 error = memory_bm_create(&orig_bm, GFP_IMAGE, PG_ANY);
1697 if (error)
1698 goto err_out;
1699
1700 error = memory_bm_create(©_bm, GFP_IMAGE, PG_ANY);
1701 if (error)
1702 goto err_out;
1703
1704 alloc_normal = 0;
1705 alloc_highmem = 0;
1706
1707 /* Count the number of saveable data pages. */
1708 save_highmem = count_highmem_pages();
1709 saveable = count_data_pages();
1710
1711 /*
1712 * Compute the total number of page frames we can use (count) and the
1713 * number of pages needed for image metadata (size).
1714 */
1715 count = saveable;
1716 saveable += save_highmem;
1717 highmem = save_highmem;
1718 size = 0;
1719 for_each_populated_zone(zone) {
1720 size += snapshot_additional_pages(zone);
1721 if (is_highmem(zone))
1722 highmem += zone_page_state(zone, NR_FREE_PAGES);
1723 else
1724 count += zone_page_state(zone, NR_FREE_PAGES);
1725 }
1726 avail_normal = count;
1727 count += highmem;
1728 count -= totalreserve_pages;
1729
1730 /* Add number of pages required for page keys (s390 only). */
1731 size += page_key_additional_pages(saveable);
1732
1733 /* Compute the maximum number of saveable pages to leave in memory. */
1734 max_size = (count - (size + PAGES_FOR_IO)) / 2
1735 - 2 * DIV_ROUND_UP(reserved_size, PAGE_SIZE);
1736 /* Compute the desired number of image pages specified by image_size. */
1737 size = DIV_ROUND_UP(image_size, PAGE_SIZE);
1738 if (size > max_size)
1739 size = max_size;
1740 /*
1741 * If the desired number of image pages is at least as large as the
1742 * current number of saveable pages in memory, allocate page frames for
1743 * the image and we're done.
1744 */
1745 if (size >= saveable) {
1746 pages = preallocate_image_highmem(save_highmem);
1747 pages += preallocate_image_memory(saveable - pages, avail_normal);
1748 goto out;
1749 }
1750
1751 /* Estimate the minimum size of the image. */
1752 pages = minimum_image_size(saveable);
1753 /*
1754 * To avoid excessive pressure on the normal zone, leave room in it to
1755 * accommodate an image of the minimum size (unless it's already too
1756 * small, in which case don't preallocate pages from it at all).
1757 */
1758 if (avail_normal > pages)
1759 avail_normal -= pages;
1760 else
1761 avail_normal = 0;
1762 if (size < pages)
1763 size = min_t(unsigned long, pages, max_size);
1764
1765 /*
1766 * Let the memory management subsystem know that we're going to need a
1767 * large number of page frames to allocate and make it free some memory.
1768 * NOTE: If this is not done, performance will be hurt badly in some
1769 * test cases.
1770 */
1771 shrink_all_memory(saveable - size);
1772
1773 /*
1774 * The number of saveable pages in memory was too high, so apply some
1775 * pressure to decrease it. First, make room for the largest possible
1776 * image and fail if that doesn't work. Next, try to decrease the size
1777 * of the image as much as indicated by 'size' using allocations from
1778 * highmem and non-highmem zones separately.
1779 */
1780 pages_highmem = preallocate_image_highmem(highmem / 2);
1781 alloc = count - max_size;
1782 if (alloc > pages_highmem)
1783 alloc -= pages_highmem;
1784 else
1785 alloc = 0;
1786 pages = preallocate_image_memory(alloc, avail_normal);
1787 if (pages < alloc) {
1788 /* We have exhausted non-highmem pages, try highmem. */
1789 alloc -= pages;
1790 pages += pages_highmem;
1791 pages_highmem = preallocate_image_highmem(alloc);
1792 if (pages_highmem < alloc)
1793 goto err_out;
1794 pages += pages_highmem;
1795 /*
1796 * size is the desired number of saveable pages to leave in
1797 * memory, so try to preallocate (all memory - size) pages.
1798 */
1799 alloc = (count - pages) - size;
1800 pages += preallocate_image_highmem(alloc);
1801 } else {
1802 /*
1803 * There are approximately max_size saveable pages at this point
1804 * and we want to reduce this number down to size.
1805 */
1806 alloc = max_size - size;
1807 size = preallocate_highmem_fraction(alloc, highmem, count);
1808 pages_highmem += size;
1809 alloc -= size;
1810 size = preallocate_image_memory(alloc, avail_normal);
1811 pages_highmem += preallocate_image_highmem(alloc - size);
1812 pages += pages_highmem + size;
1813 }
1814
1815 /*
1816 * We only need as many page frames for the image as there are saveable
1817 * pages in memory, but we have allocated more. Release the excessive
1818 * ones now.
1819 */
1820 pages -= free_unnecessary_pages();
1821
1822 out:
1823 stop = ktime_get();
1824 pr_cont("done (allocated %lu pages)\n", pages);
1825 swsusp_show_speed(start, stop, pages, "Allocated");
1826
1827 return 0;
1828
1829 err_out:
1830 pr_cont("\n");
1831 swsusp_free();
1832 return -ENOMEM;
1833}
1834
1835#ifdef CONFIG_HIGHMEM
1836/**
1837 * count_pages_for_highmem - Count non-highmem pages needed for copying highmem.
1838 *
1839 * Compute the number of non-highmem pages that will be necessary for creating
1840 * copies of highmem pages.
1841 */
1842static unsigned int count_pages_for_highmem(unsigned int nr_highmem)
1843{
1844 unsigned int free_highmem = count_free_highmem_pages() + alloc_highmem;
1845
1846 if (free_highmem >= nr_highmem)
1847 nr_highmem = 0;
1848 else
1849 nr_highmem -= free_highmem;
1850
1851 return nr_highmem;
1852}
1853#else
1854static unsigned int count_pages_for_highmem(unsigned int nr_highmem) { return 0; }
1855#endif /* CONFIG_HIGHMEM */
1856
1857/**
1858 * enough_free_mem - Check if there is enough free memory for the image.
1859 */
1860static int enough_free_mem(unsigned int nr_pages, unsigned int nr_highmem)
1861{
1862 struct zone *zone;
1863 unsigned int free = alloc_normal;
1864
1865 for_each_populated_zone(zone)
1866 if (!is_highmem(zone))
1867 free += zone_page_state(zone, NR_FREE_PAGES);
1868
1869 nr_pages += count_pages_for_highmem(nr_highmem);
1870 pr_debug("Normal pages needed: %u + %u, available pages: %u\n",
1871 nr_pages, PAGES_FOR_IO, free);
1872
1873 return free > nr_pages + PAGES_FOR_IO;
1874}
1875
1876#ifdef CONFIG_HIGHMEM
1877/**
1878 * get_highmem_buffer - Allocate a buffer for highmem pages.
1879 *
1880 * If there are some highmem pages in the hibernation image, we may need a
1881 * buffer to copy them and/or load their data.
1882 */
1883static inline int get_highmem_buffer(int safe_needed)
1884{
1885 buffer = get_image_page(GFP_ATOMIC, safe_needed);
1886 return buffer ? 0 : -ENOMEM;
1887}
1888
1889/**
1890 * alloc_highmem_image_pages - Allocate some highmem pages for the image.
1891 *
1892 * Try to allocate as many pages as needed, but if the number of free highmem
1893 * pages is less than that, allocate them all.
1894 */
1895static inline unsigned int alloc_highmem_pages(struct memory_bitmap *bm,
1896 unsigned int nr_highmem)
1897{
1898 unsigned int to_alloc = count_free_highmem_pages();
1899
1900 if (to_alloc > nr_highmem)
1901 to_alloc = nr_highmem;
1902
1903 nr_highmem -= to_alloc;
1904 while (to_alloc-- > 0) {
1905 struct page *page;
1906
1907 page = alloc_image_page(__GFP_HIGHMEM|__GFP_KSWAPD_RECLAIM);
1908 memory_bm_set_bit(bm, page_to_pfn(page));
1909 }
1910 return nr_highmem;
1911}
1912#else
1913static inline int get_highmem_buffer(int safe_needed) { return 0; }
1914
1915static inline unsigned int alloc_highmem_pages(struct memory_bitmap *bm,
1916 unsigned int n) { return 0; }
1917#endif /* CONFIG_HIGHMEM */
1918
1919/**
1920 * swsusp_alloc - Allocate memory for hibernation image.
1921 *
1922 * We first try to allocate as many highmem pages as there are
1923 * saveable highmem pages in the system. If that fails, we allocate
1924 * non-highmem pages for the copies of the remaining highmem ones.
1925 *
1926 * In this approach it is likely that the copies of highmem pages will
1927 * also be located in the high memory, because of the way in which
1928 * copy_data_pages() works.
1929 */
1930static int swsusp_alloc(struct memory_bitmap *copy_bm,
1931 unsigned int nr_pages, unsigned int nr_highmem)
1932{
1933 if (nr_highmem > 0) {
1934 if (get_highmem_buffer(PG_ANY))
1935 goto err_out;
1936 if (nr_highmem > alloc_highmem) {
1937 nr_highmem -= alloc_highmem;
1938 nr_pages += alloc_highmem_pages(copy_bm, nr_highmem);
1939 }
1940 }
1941 if (nr_pages > alloc_normal) {
1942 nr_pages -= alloc_normal;
1943 while (nr_pages-- > 0) {
1944 struct page *page;
1945
1946 page = alloc_image_page(GFP_ATOMIC);
1947 if (!page)
1948 goto err_out;
1949 memory_bm_set_bit(copy_bm, page_to_pfn(page));
1950 }
1951 }
1952
1953 return 0;
1954
1955 err_out:
1956 swsusp_free();
1957 return -ENOMEM;
1958}
1959
1960asmlinkage __visible int swsusp_save(void)
1961{
1962 unsigned int nr_pages, nr_highmem;
1963
1964 pr_info("Creating hibernation image:\n");
1965
1966 drain_local_pages(NULL);
1967 nr_pages = count_data_pages();
1968 nr_highmem = count_highmem_pages();
1969 pr_info("Need to copy %u pages\n", nr_pages + nr_highmem);
1970
1971 if (!enough_free_mem(nr_pages, nr_highmem)) {
1972 pr_err("Not enough free memory\n");
1973 return -ENOMEM;
1974 }
1975
1976 if (swsusp_alloc(©_bm, nr_pages, nr_highmem)) {
1977 pr_err("Memory allocation failed\n");
1978 return -ENOMEM;
1979 }
1980
1981 /*
1982 * During allocating of suspend pagedir, new cold pages may appear.
1983 * Kill them.
1984 */
1985 drain_local_pages(NULL);
1986 copy_data_pages(©_bm, &orig_bm);
1987
1988 /*
1989 * End of critical section. From now on, we can write to memory,
1990 * but we should not touch disk. This specially means we must _not_
1991 * touch swap space! Except we must write out our image of course.
1992 */
1993
1994 nr_pages += nr_highmem;
1995 nr_copy_pages = nr_pages;
1996 nr_meta_pages = DIV_ROUND_UP(nr_pages * sizeof(long), PAGE_SIZE);
1997
1998 pr_info("Hibernation image created (%d pages copied)\n", nr_pages);
1999
2000 return 0;
2001}
2002
2003#ifndef CONFIG_ARCH_HIBERNATION_HEADER
2004static int init_header_complete(struct swsusp_info *info)
2005{
2006 memcpy(&info->uts, init_utsname(), sizeof(struct new_utsname));
2007 info->version_code = LINUX_VERSION_CODE;
2008 return 0;
2009}
2010
2011static char *check_image_kernel(struct swsusp_info *info)
2012{
2013 if (info->version_code != LINUX_VERSION_CODE)
2014 return "kernel version";
2015 if (strcmp(info->uts.sysname,init_utsname()->sysname))
2016 return "system type";
2017 if (strcmp(info->uts.release,init_utsname()->release))
2018 return "kernel release";
2019 if (strcmp(info->uts.version,init_utsname()->version))
2020 return "version";
2021 if (strcmp(info->uts.machine,init_utsname()->machine))
2022 return "machine";
2023 return NULL;
2024}
2025#endif /* CONFIG_ARCH_HIBERNATION_HEADER */
2026
2027unsigned long snapshot_get_image_size(void)
2028{
2029 return nr_copy_pages + nr_meta_pages + 1;
2030}
2031
2032static int init_header(struct swsusp_info *info)
2033{
2034 memset(info, 0, sizeof(struct swsusp_info));
2035 info->num_physpages = get_num_physpages();
2036 info->image_pages = nr_copy_pages;
2037 info->pages = snapshot_get_image_size();
2038 info->size = info->pages;
2039 info->size <<= PAGE_SHIFT;
2040 return init_header_complete(info);
2041}
2042
2043/**
2044 * pack_pfns - Prepare PFNs for saving.
2045 * @bm: Memory bitmap.
2046 * @buf: Memory buffer to store the PFNs in.
2047 *
2048 * PFNs corresponding to set bits in @bm are stored in the area of memory
2049 * pointed to by @buf (1 page at a time).
2050 */
2051static inline void pack_pfns(unsigned long *buf, struct memory_bitmap *bm)
2052{
2053 int j;
2054
2055 for (j = 0; j < PAGE_SIZE / sizeof(long); j++) {
2056 buf[j] = memory_bm_next_pfn(bm);
2057 if (unlikely(buf[j] == BM_END_OF_MAP))
2058 break;
2059 /* Save page key for data page (s390 only). */
2060 page_key_read(buf + j);
2061 }
2062}
2063
2064/**
2065 * snapshot_read_next - Get the address to read the next image page from.
2066 * @handle: Snapshot handle to be used for the reading.
2067 *
2068 * On the first call, @handle should point to a zeroed snapshot_handle
2069 * structure. The structure gets populated then and a pointer to it should be
2070 * passed to this function every next time.
2071 *
2072 * On success, the function returns a positive number. Then, the caller
2073 * is allowed to read up to the returned number of bytes from the memory
2074 * location computed by the data_of() macro.
2075 *
2076 * The function returns 0 to indicate the end of the data stream condition,
2077 * and negative numbers are returned on errors. If that happens, the structure
2078 * pointed to by @handle is not updated and should not be used any more.
2079 */
2080int snapshot_read_next(struct snapshot_handle *handle)
2081{
2082 if (handle->cur > nr_meta_pages + nr_copy_pages)
2083 return 0;
2084
2085 if (!buffer) {
2086 /* This makes the buffer be freed by swsusp_free() */
2087 buffer = get_image_page(GFP_ATOMIC, PG_ANY);
2088 if (!buffer)
2089 return -ENOMEM;
2090 }
2091 if (!handle->cur) {
2092 int error;
2093
2094 error = init_header((struct swsusp_info *)buffer);
2095 if (error)
2096 return error;
2097 handle->buffer = buffer;
2098 memory_bm_position_reset(&orig_bm);
2099 memory_bm_position_reset(©_bm);
2100 } else if (handle->cur <= nr_meta_pages) {
2101 clear_page(buffer);
2102 pack_pfns(buffer, &orig_bm);
2103 } else {
2104 struct page *page;
2105
2106 page = pfn_to_page(memory_bm_next_pfn(©_bm));
2107 if (PageHighMem(page)) {
2108 /*
2109 * Highmem pages are copied to the buffer,
2110 * because we can't return with a kmapped
2111 * highmem page (we may not be called again).
2112 */
2113 void *kaddr;
2114
2115 kaddr = kmap_atomic(page);
2116 copy_page(buffer, kaddr);
2117 kunmap_atomic(kaddr);
2118 handle->buffer = buffer;
2119 } else {
2120 handle->buffer = page_address(page);
2121 }
2122 }
2123 handle->cur++;
2124 return PAGE_SIZE;
2125}
2126
2127static void duplicate_memory_bitmap(struct memory_bitmap *dst,
2128 struct memory_bitmap *src)
2129{
2130 unsigned long pfn;
2131
2132 memory_bm_position_reset(src);
2133 pfn = memory_bm_next_pfn(src);
2134 while (pfn != BM_END_OF_MAP) {
2135 memory_bm_set_bit(dst, pfn);
2136 pfn = memory_bm_next_pfn(src);
2137 }
2138}
2139
2140/**
2141 * mark_unsafe_pages - Mark pages that were used before hibernation.
2142 *
2143 * Mark the pages that cannot be used for storing the image during restoration,
2144 * because they conflict with the pages that had been used before hibernation.
2145 */
2146static void mark_unsafe_pages(struct memory_bitmap *bm)
2147{
2148 unsigned long pfn;
2149
2150 /* Clear the "free"/"unsafe" bit for all PFNs */
2151 memory_bm_position_reset(free_pages_map);
2152 pfn = memory_bm_next_pfn(free_pages_map);
2153 while (pfn != BM_END_OF_MAP) {
2154 memory_bm_clear_current(free_pages_map);
2155 pfn = memory_bm_next_pfn(free_pages_map);
2156 }
2157
2158 /* Mark pages that correspond to the "original" PFNs as "unsafe" */
2159 duplicate_memory_bitmap(free_pages_map, bm);
2160
2161 allocated_unsafe_pages = 0;
2162}
2163
2164static int check_header(struct swsusp_info *info)
2165{
2166 char *reason;
2167
2168 reason = check_image_kernel(info);
2169 if (!reason && info->num_physpages != get_num_physpages())
2170 reason = "memory size";
2171 if (reason) {
2172 pr_err("Image mismatch: %s\n", reason);
2173 return -EPERM;
2174 }
2175 return 0;
2176}
2177
2178/**
2179 * load header - Check the image header and copy the data from it.
2180 */
2181static int load_header(struct swsusp_info *info)
2182{
2183 int error;
2184
2185 restore_pblist = NULL;
2186 error = check_header(info);
2187 if (!error) {
2188 nr_copy_pages = info->image_pages;
2189 nr_meta_pages = info->pages - info->image_pages - 1;
2190 }
2191 return error;
2192}
2193
2194/**
2195 * unpack_orig_pfns - Set bits corresponding to given PFNs in a memory bitmap.
2196 * @bm: Memory bitmap.
2197 * @buf: Area of memory containing the PFNs.
2198 *
2199 * For each element of the array pointed to by @buf (1 page at a time), set the
2200 * corresponding bit in @bm.
2201 */
2202static int unpack_orig_pfns(unsigned long *buf, struct memory_bitmap *bm)
2203{
2204 int j;
2205
2206 for (j = 0; j < PAGE_SIZE / sizeof(long); j++) {
2207 if (unlikely(buf[j] == BM_END_OF_MAP))
2208 break;
2209
2210 /* Extract and buffer page key for data page (s390 only). */
2211 page_key_memorize(buf + j);
2212
2213 if (pfn_valid(buf[j]) && memory_bm_pfn_present(bm, buf[j]))
2214 memory_bm_set_bit(bm, buf[j]);
2215 else
2216 return -EFAULT;
2217 }
2218
2219 return 0;
2220}
2221
2222#ifdef CONFIG_HIGHMEM
2223/*
2224 * struct highmem_pbe is used for creating the list of highmem pages that
2225 * should be restored atomically during the resume from disk, because the page
2226 * frames they have occupied before the suspend are in use.
2227 */
2228struct highmem_pbe {
2229 struct page *copy_page; /* data is here now */
2230 struct page *orig_page; /* data was here before the suspend */
2231 struct highmem_pbe *next;
2232};
2233
2234/*
2235 * List of highmem PBEs needed for restoring the highmem pages that were
2236 * allocated before the suspend and included in the suspend image, but have
2237 * also been allocated by the "resume" kernel, so their contents cannot be
2238 * written directly to their "original" page frames.
2239 */
2240static struct highmem_pbe *highmem_pblist;
2241
2242/**
2243 * count_highmem_image_pages - Compute the number of highmem pages in the image.
2244 * @bm: Memory bitmap.
2245 *
2246 * The bits in @bm that correspond to image pages are assumed to be set.
2247 */
2248static unsigned int count_highmem_image_pages(struct memory_bitmap *bm)
2249{
2250 unsigned long pfn;
2251 unsigned int cnt = 0;
2252
2253 memory_bm_position_reset(bm);
2254 pfn = memory_bm_next_pfn(bm);
2255 while (pfn != BM_END_OF_MAP) {
2256 if (PageHighMem(pfn_to_page(pfn)))
2257 cnt++;
2258
2259 pfn = memory_bm_next_pfn(bm);
2260 }
2261 return cnt;
2262}
2263
2264static unsigned int safe_highmem_pages;
2265
2266static struct memory_bitmap *safe_highmem_bm;
2267
2268/**
2269 * prepare_highmem_image - Allocate memory for loading highmem data from image.
2270 * @bm: Pointer to an uninitialized memory bitmap structure.
2271 * @nr_highmem_p: Pointer to the number of highmem image pages.
2272 *
2273 * Try to allocate as many highmem pages as there are highmem image pages
2274 * (@nr_highmem_p points to the variable containing the number of highmem image
2275 * pages). The pages that are "safe" (ie. will not be overwritten when the
2276 * hibernation image is restored entirely) have the corresponding bits set in
2277 * @bm (it must be unitialized).
2278 *
2279 * NOTE: This function should not be called if there are no highmem image pages.
2280 */
2281static int prepare_highmem_image(struct memory_bitmap *bm,
2282 unsigned int *nr_highmem_p)
2283{
2284 unsigned int to_alloc;
2285
2286 if (memory_bm_create(bm, GFP_ATOMIC, PG_SAFE))
2287 return -ENOMEM;
2288
2289 if (get_highmem_buffer(PG_SAFE))
2290 return -ENOMEM;
2291
2292 to_alloc = count_free_highmem_pages();
2293 if (to_alloc > *nr_highmem_p)
2294 to_alloc = *nr_highmem_p;
2295 else
2296 *nr_highmem_p = to_alloc;
2297
2298 safe_highmem_pages = 0;
2299 while (to_alloc-- > 0) {
2300 struct page *page;
2301
2302 page = alloc_page(__GFP_HIGHMEM);
2303 if (!swsusp_page_is_free(page)) {
2304 /* The page is "safe", set its bit the bitmap */
2305 memory_bm_set_bit(bm, page_to_pfn(page));
2306 safe_highmem_pages++;
2307 }
2308 /* Mark the page as allocated */
2309 swsusp_set_page_forbidden(page);
2310 swsusp_set_page_free(page);
2311 }
2312 memory_bm_position_reset(bm);
2313 safe_highmem_bm = bm;
2314 return 0;
2315}
2316
2317static struct page *last_highmem_page;
2318
2319/**
2320 * get_highmem_page_buffer - Prepare a buffer to store a highmem image page.
2321 *
2322 * For a given highmem image page get a buffer that suspend_write_next() should
2323 * return to its caller to write to.
2324 *
2325 * If the page is to be saved to its "original" page frame or a copy of
2326 * the page is to be made in the highmem, @buffer is returned. Otherwise,
2327 * the copy of the page is to be made in normal memory, so the address of
2328 * the copy is returned.
2329 *
2330 * If @buffer is returned, the caller of suspend_write_next() will write
2331 * the page's contents to @buffer, so they will have to be copied to the
2332 * right location on the next call to suspend_write_next() and it is done
2333 * with the help of copy_last_highmem_page(). For this purpose, if
2334 * @buffer is returned, @last_highmem_page is set to the page to which
2335 * the data will have to be copied from @buffer.
2336 */
2337static void *get_highmem_page_buffer(struct page *page,
2338 struct chain_allocator *ca)
2339{
2340 struct highmem_pbe *pbe;
2341 void *kaddr;
2342
2343 if (swsusp_page_is_forbidden(page) && swsusp_page_is_free(page)) {
2344 /*
2345 * We have allocated the "original" page frame and we can
2346 * use it directly to store the loaded page.
2347 */
2348 last_highmem_page = page;
2349 return buffer;
2350 }
2351 /*
2352 * The "original" page frame has not been allocated and we have to
2353 * use a "safe" page frame to store the loaded page.
2354 */
2355 pbe = chain_alloc(ca, sizeof(struct highmem_pbe));
2356 if (!pbe) {
2357 swsusp_free();
2358 return ERR_PTR(-ENOMEM);
2359 }
2360 pbe->orig_page = page;
2361 if (safe_highmem_pages > 0) {
2362 struct page *tmp;
2363
2364 /* Copy of the page will be stored in high memory */
2365 kaddr = buffer;
2366 tmp = pfn_to_page(memory_bm_next_pfn(safe_highmem_bm));
2367 safe_highmem_pages--;
2368 last_highmem_page = tmp;
2369 pbe->copy_page = tmp;
2370 } else {
2371 /* Copy of the page will be stored in normal memory */
2372 kaddr = safe_pages_list;
2373 safe_pages_list = safe_pages_list->next;
2374 pbe->copy_page = virt_to_page(kaddr);
2375 }
2376 pbe->next = highmem_pblist;
2377 highmem_pblist = pbe;
2378 return kaddr;
2379}
2380
2381/**
2382 * copy_last_highmem_page - Copy most the most recent highmem image page.
2383 *
2384 * Copy the contents of a highmem image from @buffer, where the caller of
2385 * snapshot_write_next() has stored them, to the right location represented by
2386 * @last_highmem_page .
2387 */
2388static void copy_last_highmem_page(void)
2389{
2390 if (last_highmem_page) {
2391 void *dst;
2392
2393 dst = kmap_atomic(last_highmem_page);
2394 copy_page(dst, buffer);
2395 kunmap_atomic(dst);
2396 last_highmem_page = NULL;
2397 }
2398}
2399
2400static inline int last_highmem_page_copied(void)
2401{
2402 return !last_highmem_page;
2403}
2404
2405static inline void free_highmem_data(void)
2406{
2407 if (safe_highmem_bm)
2408 memory_bm_free(safe_highmem_bm, PG_UNSAFE_CLEAR);
2409
2410 if (buffer)
2411 free_image_page(buffer, PG_UNSAFE_CLEAR);
2412}
2413#else
2414static unsigned int count_highmem_image_pages(struct memory_bitmap *bm) { return 0; }
2415
2416static inline int prepare_highmem_image(struct memory_bitmap *bm,
2417 unsigned int *nr_highmem_p) { return 0; }
2418
2419static inline void *get_highmem_page_buffer(struct page *page,
2420 struct chain_allocator *ca)
2421{
2422 return ERR_PTR(-EINVAL);
2423}
2424
2425static inline void copy_last_highmem_page(void) {}
2426static inline int last_highmem_page_copied(void) { return 1; }
2427static inline void free_highmem_data(void) {}
2428#endif /* CONFIG_HIGHMEM */
2429
2430#define PBES_PER_LINKED_PAGE (LINKED_PAGE_DATA_SIZE / sizeof(struct pbe))
2431
2432/**
2433 * prepare_image - Make room for loading hibernation image.
2434 * @new_bm: Unitialized memory bitmap structure.
2435 * @bm: Memory bitmap with unsafe pages marked.
2436 *
2437 * Use @bm to mark the pages that will be overwritten in the process of
2438 * restoring the system memory state from the suspend image ("unsafe" pages)
2439 * and allocate memory for the image.
2440 *
2441 * The idea is to allocate a new memory bitmap first and then allocate
2442 * as many pages as needed for image data, but without specifying what those
2443 * pages will be used for just yet. Instead, we mark them all as allocated and
2444 * create a lists of "safe" pages to be used later. On systems with high
2445 * memory a list of "safe" highmem pages is created too.
2446 */
2447static int prepare_image(struct memory_bitmap *new_bm, struct memory_bitmap *bm)
2448{
2449 unsigned int nr_pages, nr_highmem;
2450 struct linked_page *lp;
2451 int error;
2452
2453 /* If there is no highmem, the buffer will not be necessary */
2454 free_image_page(buffer, PG_UNSAFE_CLEAR);
2455 buffer = NULL;
2456
2457 nr_highmem = count_highmem_image_pages(bm);
2458 mark_unsafe_pages(bm);
2459
2460 error = memory_bm_create(new_bm, GFP_ATOMIC, PG_SAFE);
2461 if (error)
2462 goto Free;
2463
2464 duplicate_memory_bitmap(new_bm, bm);
2465 memory_bm_free(bm, PG_UNSAFE_KEEP);
2466 if (nr_highmem > 0) {
2467 error = prepare_highmem_image(bm, &nr_highmem);
2468 if (error)
2469 goto Free;
2470 }
2471 /*
2472 * Reserve some safe pages for potential later use.
2473 *
2474 * NOTE: This way we make sure there will be enough safe pages for the
2475 * chain_alloc() in get_buffer(). It is a bit wasteful, but
2476 * nr_copy_pages cannot be greater than 50% of the memory anyway.
2477 *
2478 * nr_copy_pages cannot be less than allocated_unsafe_pages too.
2479 */
2480 nr_pages = nr_copy_pages - nr_highmem - allocated_unsafe_pages;
2481 nr_pages = DIV_ROUND_UP(nr_pages, PBES_PER_LINKED_PAGE);
2482 while (nr_pages > 0) {
2483 lp = get_image_page(GFP_ATOMIC, PG_SAFE);
2484 if (!lp) {
2485 error = -ENOMEM;
2486 goto Free;
2487 }
2488 lp->next = safe_pages_list;
2489 safe_pages_list = lp;
2490 nr_pages--;
2491 }
2492 /* Preallocate memory for the image */
2493 nr_pages = nr_copy_pages - nr_highmem - allocated_unsafe_pages;
2494 while (nr_pages > 0) {
2495 lp = (struct linked_page *)get_zeroed_page(GFP_ATOMIC);
2496 if (!lp) {
2497 error = -ENOMEM;
2498 goto Free;
2499 }
2500 if (!swsusp_page_is_free(virt_to_page(lp))) {
2501 /* The page is "safe", add it to the list */
2502 lp->next = safe_pages_list;
2503 safe_pages_list = lp;
2504 }
2505 /* Mark the page as allocated */
2506 swsusp_set_page_forbidden(virt_to_page(lp));
2507 swsusp_set_page_free(virt_to_page(lp));
2508 nr_pages--;
2509 }
2510 return 0;
2511
2512 Free:
2513 swsusp_free();
2514 return error;
2515}
2516
2517/**
2518 * get_buffer - Get the address to store the next image data page.
2519 *
2520 * Get the address that snapshot_write_next() should return to its caller to
2521 * write to.
2522 */
2523static void *get_buffer(struct memory_bitmap *bm, struct chain_allocator *ca)
2524{
2525 struct pbe *pbe;
2526 struct page *page;
2527 unsigned long pfn = memory_bm_next_pfn(bm);
2528
2529 if (pfn == BM_END_OF_MAP)
2530 return ERR_PTR(-EFAULT);
2531
2532 page = pfn_to_page(pfn);
2533 if (PageHighMem(page))
2534 return get_highmem_page_buffer(page, ca);
2535
2536 if (swsusp_page_is_forbidden(page) && swsusp_page_is_free(page))
2537 /*
2538 * We have allocated the "original" page frame and we can
2539 * use it directly to store the loaded page.
2540 */
2541 return page_address(page);
2542
2543 /*
2544 * The "original" page frame has not been allocated and we have to
2545 * use a "safe" page frame to store the loaded page.
2546 */
2547 pbe = chain_alloc(ca, sizeof(struct pbe));
2548 if (!pbe) {
2549 swsusp_free();
2550 return ERR_PTR(-ENOMEM);
2551 }
2552 pbe->orig_address = page_address(page);
2553 pbe->address = safe_pages_list;
2554 safe_pages_list = safe_pages_list->next;
2555 pbe->next = restore_pblist;
2556 restore_pblist = pbe;
2557 return pbe->address;
2558}
2559
2560/**
2561 * snapshot_write_next - Get the address to store the next image page.
2562 * @handle: Snapshot handle structure to guide the writing.
2563 *
2564 * On the first call, @handle should point to a zeroed snapshot_handle
2565 * structure. The structure gets populated then and a pointer to it should be
2566 * passed to this function every next time.
2567 *
2568 * On success, the function returns a positive number. Then, the caller
2569 * is allowed to write up to the returned number of bytes to the memory
2570 * location computed by the data_of() macro.
2571 *
2572 * The function returns 0 to indicate the "end of file" condition. Negative
2573 * numbers are returned on errors, in which cases the structure pointed to by
2574 * @handle is not updated and should not be used any more.
2575 */
2576int snapshot_write_next(struct snapshot_handle *handle)
2577{
2578 static struct chain_allocator ca;
2579 int error = 0;
2580
2581 /* Check if we have already loaded the entire image */
2582 if (handle->cur > 1 && handle->cur > nr_meta_pages + nr_copy_pages)
2583 return 0;
2584
2585 handle->sync_read = 1;
2586
2587 if (!handle->cur) {
2588 if (!buffer)
2589 /* This makes the buffer be freed by swsusp_free() */
2590 buffer = get_image_page(GFP_ATOMIC, PG_ANY);
2591
2592 if (!buffer)
2593 return -ENOMEM;
2594
2595 handle->buffer = buffer;
2596 } else if (handle->cur == 1) {
2597 error = load_header(buffer);
2598 if (error)
2599 return error;
2600
2601 safe_pages_list = NULL;
2602
2603 error = memory_bm_create(©_bm, GFP_ATOMIC, PG_ANY);
2604 if (error)
2605 return error;
2606
2607 /* Allocate buffer for page keys. */
2608 error = page_key_alloc(nr_copy_pages);
2609 if (error)
2610 return error;
2611
2612 hibernate_restore_protection_begin();
2613 } else if (handle->cur <= nr_meta_pages + 1) {
2614 error = unpack_orig_pfns(buffer, ©_bm);
2615 if (error)
2616 return error;
2617
2618 if (handle->cur == nr_meta_pages + 1) {
2619 error = prepare_image(&orig_bm, ©_bm);
2620 if (error)
2621 return error;
2622
2623 chain_init(&ca, GFP_ATOMIC, PG_SAFE);
2624 memory_bm_position_reset(&orig_bm);
2625 restore_pblist = NULL;
2626 handle->buffer = get_buffer(&orig_bm, &ca);
2627 handle->sync_read = 0;
2628 if (IS_ERR(handle->buffer))
2629 return PTR_ERR(handle->buffer);
2630 }
2631 } else {
2632 copy_last_highmem_page();
2633 /* Restore page key for data page (s390 only). */
2634 page_key_write(handle->buffer);
2635 hibernate_restore_protect_page(handle->buffer);
2636 handle->buffer = get_buffer(&orig_bm, &ca);
2637 if (IS_ERR(handle->buffer))
2638 return PTR_ERR(handle->buffer);
2639 if (handle->buffer != buffer)
2640 handle->sync_read = 0;
2641 }
2642 handle->cur++;
2643 return PAGE_SIZE;
2644}
2645
2646/**
2647 * snapshot_write_finalize - Complete the loading of a hibernation image.
2648 *
2649 * Must be called after the last call to snapshot_write_next() in case the last
2650 * page in the image happens to be a highmem page and its contents should be
2651 * stored in highmem. Additionally, it recycles bitmap memory that's not
2652 * necessary any more.
2653 */
2654void snapshot_write_finalize(struct snapshot_handle *handle)
2655{
2656 copy_last_highmem_page();
2657 /* Restore page key for data page (s390 only). */
2658 page_key_write(handle->buffer);
2659 page_key_free();
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 */