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1// SPDX-License-Identifier: GPL-2.0-only
2/*
3 * linux/kernel/power/snapshot.c
4 *
5 * This file provides system snapshot/restore functionality for swsusp.
6 *
7 * Copyright (C) 1998-2005 Pavel Machek <pavel@ucw.cz>
8 * Copyright (C) 2006 Rafael J. Wysocki <rjw@sisk.pl>
9 */
10
11#define pr_fmt(fmt) "PM: hibernation: " fmt
12
13#include <linux/version.h>
14#include <linux/module.h>
15#include <linux/mm.h>
16#include <linux/suspend.h>
17#include <linux/delay.h>
18#include <linux/bitops.h>
19#include <linux/spinlock.h>
20#include <linux/kernel.h>
21#include <linux/pm.h>
22#include <linux/device.h>
23#include <linux/init.h>
24#include <linux/memblock.h>
25#include <linux/nmi.h>
26#include <linux/syscalls.h>
27#include <linux/console.h>
28#include <linux/highmem.h>
29#include <linux/list.h>
30#include <linux/slab.h>
31#include <linux/compiler.h>
32#include <linux/ktime.h>
33#include <linux/set_memory.h>
34
35#include <linux/uaccess.h>
36#include <asm/mmu_context.h>
37#include <asm/tlbflush.h>
38#include <asm/io.h>
39
40#include "power.h"
41
42#if defined(CONFIG_STRICT_KERNEL_RWX) && defined(CONFIG_ARCH_HAS_SET_MEMORY)
43static bool hibernate_restore_protection;
44static bool hibernate_restore_protection_active;
45
46void enable_restore_image_protection(void)
47{
48 hibernate_restore_protection = true;
49}
50
51static inline void hibernate_restore_protection_begin(void)
52{
53 hibernate_restore_protection_active = hibernate_restore_protection;
54}
55
56static inline void hibernate_restore_protection_end(void)
57{
58 hibernate_restore_protection_active = false;
59}
60
61static inline void hibernate_restore_protect_page(void *page_address)
62{
63 if (hibernate_restore_protection_active)
64 set_memory_ro((unsigned long)page_address, 1);
65}
66
67static inline void hibernate_restore_unprotect_page(void *page_address)
68{
69 if (hibernate_restore_protection_active)
70 set_memory_rw((unsigned long)page_address, 1);
71}
72#else
73static inline void hibernate_restore_protection_begin(void) {}
74static inline void hibernate_restore_protection_end(void) {}
75static inline void hibernate_restore_protect_page(void *page_address) {}
76static inline void hibernate_restore_unprotect_page(void *page_address) {}
77#endif /* CONFIG_STRICT_KERNEL_RWX && CONFIG_ARCH_HAS_SET_MEMORY */
78
79static int swsusp_page_is_free(struct page *);
80static void swsusp_set_page_forbidden(struct page *);
81static void swsusp_unset_page_forbidden(struct page *);
82
83/*
84 * Number of bytes to reserve for memory allocations made by device drivers
85 * from their ->freeze() and ->freeze_noirq() callbacks so that they don't
86 * cause image creation to fail (tunable via /sys/power/reserved_size).
87 */
88unsigned long reserved_size;
89
90void __init hibernate_reserved_size_init(void)
91{
92 reserved_size = SPARE_PAGES * PAGE_SIZE;
93}
94
95/*
96 * Preferred image size in bytes (tunable via /sys/power/image_size).
97 * When it is set to N, swsusp will do its best to ensure the image
98 * size will not exceed N bytes, but if that is impossible, it will
99 * try to create the smallest image possible.
100 */
101unsigned long image_size;
102
103void __init hibernate_image_size_init(void)
104{
105 image_size = ((totalram_pages() * 2) / 5) * PAGE_SIZE;
106}
107
108/*
109 * List of PBEs needed for restoring the pages that were allocated before
110 * the suspend and included in the suspend image, but have also been
111 * allocated by the "resume" kernel, so their contents cannot be written
112 * directly to their "original" page frames.
113 */
114struct pbe *restore_pblist;
115
116/* struct linked_page is used to build chains of pages */
117
118#define LINKED_PAGE_DATA_SIZE (PAGE_SIZE - sizeof(void *))
119
120struct linked_page {
121 struct linked_page *next;
122 char data[LINKED_PAGE_DATA_SIZE];
123} __packed;
124
125/*
126 * List of "safe" pages (ie. pages that were not used by the image kernel
127 * before hibernation) that may be used as temporary storage for image kernel
128 * memory contents.
129 */
130static struct linked_page *safe_pages_list;
131
132/* Pointer to an auxiliary buffer (1 page) */
133static void *buffer;
134
135#define PG_ANY 0
136#define PG_SAFE 1
137#define PG_UNSAFE_CLEAR 1
138#define PG_UNSAFE_KEEP 0
139
140static unsigned int allocated_unsafe_pages;
141
142/**
143 * get_image_page - Allocate a page for a hibernation image.
144 * @gfp_mask: GFP mask for the allocation.
145 * @safe_needed: Get pages that were not used before hibernation (restore only)
146 *
147 * During image restoration, for storing the PBE list and the image data, we can
148 * only use memory pages that do not conflict with the pages used before
149 * hibernation. The "unsafe" pages have PageNosaveFree set and we count them
150 * using allocated_unsafe_pages.
151 *
152 * Each allocated image page is marked as PageNosave and PageNosaveFree so that
153 * swsusp_free() can release it.
154 */
155static void *get_image_page(gfp_t gfp_mask, int safe_needed)
156{
157 void *res;
158
159 res = (void *)get_zeroed_page(gfp_mask);
160 if (safe_needed)
161 while (res && swsusp_page_is_free(virt_to_page(res))) {
162 /* The page is unsafe, mark it for swsusp_free() */
163 swsusp_set_page_forbidden(virt_to_page(res));
164 allocated_unsafe_pages++;
165 res = (void *)get_zeroed_page(gfp_mask);
166 }
167 if (res) {
168 swsusp_set_page_forbidden(virt_to_page(res));
169 swsusp_set_page_free(virt_to_page(res));
170 }
171 return res;
172}
173
174static void *__get_safe_page(gfp_t gfp_mask)
175{
176 if (safe_pages_list) {
177 void *ret = safe_pages_list;
178
179 safe_pages_list = safe_pages_list->next;
180 memset(ret, 0, PAGE_SIZE);
181 return ret;
182 }
183 return get_image_page(gfp_mask, PG_SAFE);
184}
185
186unsigned long get_safe_page(gfp_t gfp_mask)
187{
188 return (unsigned long)__get_safe_page(gfp_mask);
189}
190
191static struct page *alloc_image_page(gfp_t gfp_mask)
192{
193 struct page *page;
194
195 page = alloc_page(gfp_mask);
196 if (page) {
197 swsusp_set_page_forbidden(page);
198 swsusp_set_page_free(page);
199 }
200 return page;
201}
202
203static void recycle_safe_page(void *page_address)
204{
205 struct linked_page *lp = page_address;
206
207 lp->next = safe_pages_list;
208 safe_pages_list = lp;
209}
210
211/**
212 * free_image_page - Free a page allocated for hibernation image.
213 * @addr: Address of the page to free.
214 * @clear_nosave_free: If set, clear the PageNosaveFree bit for the page.
215 *
216 * The page to free should have been allocated by get_image_page() (page flags
217 * set by it are affected).
218 */
219static inline void free_image_page(void *addr, int clear_nosave_free)
220{
221 struct page *page;
222
223 BUG_ON(!virt_addr_valid(addr));
224
225 page = virt_to_page(addr);
226
227 swsusp_unset_page_forbidden(page);
228 if (clear_nosave_free)
229 swsusp_unset_page_free(page);
230
231 __free_page(page);
232}
233
234static inline void free_list_of_pages(struct linked_page *list,
235 int clear_page_nosave)
236{
237 while (list) {
238 struct linked_page *lp = list->next;
239
240 free_image_page(list, clear_page_nosave);
241 list = lp;
242 }
243}
244
245/*
246 * struct chain_allocator is used for allocating small objects out of
247 * a linked list of pages called 'the chain'.
248 *
249 * The chain grows each time when there is no room for a new object in
250 * the current page. The allocated objects cannot be freed individually.
251 * It is only possible to free them all at once, by freeing the entire
252 * chain.
253 *
254 * NOTE: The chain allocator may be inefficient if the allocated objects
255 * are not much smaller than PAGE_SIZE.
256 */
257struct chain_allocator {
258 struct linked_page *chain; /* the chain */
259 unsigned int used_space; /* total size of objects allocated out
260 of the current page */
261 gfp_t gfp_mask; /* mask for allocating pages */
262 int safe_needed; /* if set, only "safe" pages are allocated */
263};
264
265static void chain_init(struct chain_allocator *ca, gfp_t gfp_mask,
266 int safe_needed)
267{
268 ca->chain = NULL;
269 ca->used_space = LINKED_PAGE_DATA_SIZE;
270 ca->gfp_mask = gfp_mask;
271 ca->safe_needed = safe_needed;
272}
273
274static void *chain_alloc(struct chain_allocator *ca, unsigned int size)
275{
276 void *ret;
277
278 if (LINKED_PAGE_DATA_SIZE - ca->used_space < size) {
279 struct linked_page *lp;
280
281 lp = ca->safe_needed ? __get_safe_page(ca->gfp_mask) :
282 get_image_page(ca->gfp_mask, PG_ANY);
283 if (!lp)
284 return NULL;
285
286 lp->next = ca->chain;
287 ca->chain = lp;
288 ca->used_space = 0;
289 }
290 ret = ca->chain->data + ca->used_space;
291 ca->used_space += size;
292 return ret;
293}
294
295/**
296 * Data types related to memory bitmaps.
297 *
298 * Memory bitmap is a structure consiting of many linked lists of
299 * objects. The main list's elements are of type struct zone_bitmap
300 * and each of them corresonds to one zone. For each zone bitmap
301 * object there is a list of objects of type struct bm_block that
302 * represent each blocks of bitmap in which information is stored.
303 *
304 * struct memory_bitmap contains a pointer to the main list of zone
305 * bitmap objects, a struct bm_position used for browsing the bitmap,
306 * and a pointer to the list of pages used for allocating all of the
307 * zone bitmap objects and bitmap block objects.
308 *
309 * NOTE: It has to be possible to lay out the bitmap in memory
310 * using only allocations of order 0. Additionally, the bitmap is
311 * designed to work with arbitrary number of zones (this is over the
312 * top for now, but let's avoid making unnecessary assumptions ;-).
313 *
314 * struct zone_bitmap contains a pointer to a list of bitmap block
315 * objects and a pointer to the bitmap block object that has been
316 * most recently used for setting bits. Additionally, it contains the
317 * PFNs that correspond to the start and end of the represented zone.
318 *
319 * struct bm_block contains a pointer to the memory page in which
320 * information is stored (in the form of a block of bitmap)
321 * It also contains the pfns that correspond to the start and end of
322 * the represented memory area.
323 *
324 * The memory bitmap is organized as a radix tree to guarantee fast random
325 * access to the bits. There is one radix tree for each zone (as returned
326 * from create_mem_extents).
327 *
328 * One radix tree is represented by one struct mem_zone_bm_rtree. There are
329 * two linked lists for the nodes of the tree, one for the inner nodes and
330 * one for the leave nodes. The linked leave nodes are used for fast linear
331 * access of the memory bitmap.
332 *
333 * The struct rtree_node represents one node of the radix tree.
334 */
335
336#define BM_END_OF_MAP (~0UL)
337
338#define BM_BITS_PER_BLOCK (PAGE_SIZE * BITS_PER_BYTE)
339#define BM_BLOCK_SHIFT (PAGE_SHIFT + 3)
340#define BM_BLOCK_MASK ((1UL << BM_BLOCK_SHIFT) - 1)
341
342/*
343 * struct rtree_node is a wrapper struct to link the nodes
344 * of the rtree together for easy linear iteration over
345 * bits and easy freeing
346 */
347struct rtree_node {
348 struct list_head list;
349 unsigned long *data;
350};
351
352/*
353 * struct mem_zone_bm_rtree represents a bitmap used for one
354 * populated memory zone.
355 */
356struct mem_zone_bm_rtree {
357 struct list_head list; /* Link Zones together */
358 struct list_head nodes; /* Radix Tree inner nodes */
359 struct list_head leaves; /* Radix Tree leaves */
360 unsigned long start_pfn; /* Zone start page frame */
361 unsigned long end_pfn; /* Zone end page frame + 1 */
362 struct rtree_node *rtree; /* Radix Tree Root */
363 int levels; /* Number of Radix Tree Levels */
364 unsigned int blocks; /* Number of Bitmap Blocks */
365};
366
367/* strcut bm_position is used for browsing memory bitmaps */
368
369struct bm_position {
370 struct mem_zone_bm_rtree *zone;
371 struct rtree_node *node;
372 unsigned long node_pfn;
373 int node_bit;
374};
375
376struct memory_bitmap {
377 struct list_head zones;
378 struct linked_page *p_list; /* list of pages used to store zone
379 bitmap objects and bitmap block
380 objects */
381 struct bm_position cur; /* most recently used bit position */
382};
383
384/* Functions that operate on memory bitmaps */
385
386#define BM_ENTRIES_PER_LEVEL (PAGE_SIZE / sizeof(unsigned long))
387#if BITS_PER_LONG == 32
388#define BM_RTREE_LEVEL_SHIFT (PAGE_SHIFT - 2)
389#else
390#define BM_RTREE_LEVEL_SHIFT (PAGE_SHIFT - 3)
391#endif
392#define BM_RTREE_LEVEL_MASK ((1UL << BM_RTREE_LEVEL_SHIFT) - 1)
393
394/**
395 * alloc_rtree_node - Allocate a new node and add it to the radix tree.
396 *
397 * This function is used to allocate inner nodes as well as the
398 * leave nodes of the radix tree. It also adds the node to the
399 * corresponding linked list passed in by the *list parameter.
400 */
401static struct rtree_node *alloc_rtree_node(gfp_t gfp_mask, int safe_needed,
402 struct chain_allocator *ca,
403 struct list_head *list)
404{
405 struct rtree_node *node;
406
407 node = chain_alloc(ca, sizeof(struct rtree_node));
408 if (!node)
409 return NULL;
410
411 node->data = get_image_page(gfp_mask, safe_needed);
412 if (!node->data)
413 return NULL;
414
415 list_add_tail(&node->list, list);
416
417 return node;
418}
419
420/**
421 * add_rtree_block - Add a new leave node to the radix tree.
422 *
423 * The leave nodes need to be allocated in order to keep the leaves
424 * linked list in order. This is guaranteed by the zone->blocks
425 * counter.
426 */
427static int add_rtree_block(struct mem_zone_bm_rtree *zone, gfp_t gfp_mask,
428 int safe_needed, struct chain_allocator *ca)
429{
430 struct rtree_node *node, *block, **dst;
431 unsigned int levels_needed, block_nr;
432 int i;
433
434 block_nr = zone->blocks;
435 levels_needed = 0;
436
437 /* How many levels do we need for this block nr? */
438 while (block_nr) {
439 levels_needed += 1;
440 block_nr >>= BM_RTREE_LEVEL_SHIFT;
441 }
442
443 /* Make sure the rtree has enough levels */
444 for (i = zone->levels; i < levels_needed; i++) {
445 node = alloc_rtree_node(gfp_mask, safe_needed, ca,
446 &zone->nodes);
447 if (!node)
448 return -ENOMEM;
449
450 node->data[0] = (unsigned long)zone->rtree;
451 zone->rtree = node;
452 zone->levels += 1;
453 }
454
455 /* Allocate new block */
456 block = alloc_rtree_node(gfp_mask, safe_needed, ca, &zone->leaves);
457 if (!block)
458 return -ENOMEM;
459
460 /* Now walk the rtree to insert the block */
461 node = zone->rtree;
462 dst = &zone->rtree;
463 block_nr = zone->blocks;
464 for (i = zone->levels; i > 0; i--) {
465 int index;
466
467 if (!node) {
468 node = alloc_rtree_node(gfp_mask, safe_needed, ca,
469 &zone->nodes);
470 if (!node)
471 return -ENOMEM;
472 *dst = node;
473 }
474
475 index = block_nr >> ((i - 1) * BM_RTREE_LEVEL_SHIFT);
476 index &= BM_RTREE_LEVEL_MASK;
477 dst = (struct rtree_node **)&((*dst)->data[index]);
478 node = *dst;
479 }
480
481 zone->blocks += 1;
482 *dst = block;
483
484 return 0;
485}
486
487static void free_zone_bm_rtree(struct mem_zone_bm_rtree *zone,
488 int clear_nosave_free);
489
490/**
491 * create_zone_bm_rtree - Create a radix tree for one zone.
492 *
493 * Allocated the mem_zone_bm_rtree structure and initializes it.
494 * This function also allocated and builds the radix tree for the
495 * zone.
496 */
497static struct mem_zone_bm_rtree *create_zone_bm_rtree(gfp_t gfp_mask,
498 int safe_needed,
499 struct chain_allocator *ca,
500 unsigned long start,
501 unsigned long end)
502{
503 struct mem_zone_bm_rtree *zone;
504 unsigned int i, nr_blocks;
505 unsigned long pages;
506
507 pages = end - start;
508 zone = chain_alloc(ca, sizeof(struct mem_zone_bm_rtree));
509 if (!zone)
510 return NULL;
511
512 INIT_LIST_HEAD(&zone->nodes);
513 INIT_LIST_HEAD(&zone->leaves);
514 zone->start_pfn = start;
515 zone->end_pfn = end;
516 nr_blocks = DIV_ROUND_UP(pages, BM_BITS_PER_BLOCK);
517
518 for (i = 0; i < nr_blocks; i++) {
519 if (add_rtree_block(zone, gfp_mask, safe_needed, ca)) {
520 free_zone_bm_rtree(zone, PG_UNSAFE_CLEAR);
521 return NULL;
522 }
523 }
524
525 return zone;
526}
527
528/**
529 * free_zone_bm_rtree - Free the memory of the radix tree.
530 *
531 * Free all node pages of the radix tree. The mem_zone_bm_rtree
532 * structure itself is not freed here nor are the rtree_node
533 * structs.
534 */
535static void free_zone_bm_rtree(struct mem_zone_bm_rtree *zone,
536 int clear_nosave_free)
537{
538 struct rtree_node *node;
539
540 list_for_each_entry(node, &zone->nodes, list)
541 free_image_page(node->data, clear_nosave_free);
542
543 list_for_each_entry(node, &zone->leaves, list)
544 free_image_page(node->data, clear_nosave_free);
545}
546
547static void memory_bm_position_reset(struct memory_bitmap *bm)
548{
549 bm->cur.zone = list_entry(bm->zones.next, struct mem_zone_bm_rtree,
550 list);
551 bm->cur.node = list_entry(bm->cur.zone->leaves.next,
552 struct rtree_node, list);
553 bm->cur.node_pfn = 0;
554 bm->cur.node_bit = 0;
555}
556
557static void memory_bm_free(struct memory_bitmap *bm, int clear_nosave_free);
558
559struct mem_extent {
560 struct list_head hook;
561 unsigned long start;
562 unsigned long end;
563};
564
565/**
566 * free_mem_extents - Free a list of memory extents.
567 * @list: List of extents to free.
568 */
569static void free_mem_extents(struct list_head *list)
570{
571 struct mem_extent *ext, *aux;
572
573 list_for_each_entry_safe(ext, aux, list, hook) {
574 list_del(&ext->hook);
575 kfree(ext);
576 }
577}
578
579/**
580 * create_mem_extents - Create a list of memory extents.
581 * @list: List to put the extents into.
582 * @gfp_mask: Mask to use for memory allocations.
583 *
584 * The extents represent contiguous ranges of PFNs.
585 */
586static int create_mem_extents(struct list_head *list, gfp_t gfp_mask)
587{
588 struct zone *zone;
589
590 INIT_LIST_HEAD(list);
591
592 for_each_populated_zone(zone) {
593 unsigned long zone_start, zone_end;
594 struct mem_extent *ext, *cur, *aux;
595
596 zone_start = zone->zone_start_pfn;
597 zone_end = zone_end_pfn(zone);
598
599 list_for_each_entry(ext, list, hook)
600 if (zone_start <= ext->end)
601 break;
602
603 if (&ext->hook == list || zone_end < ext->start) {
604 /* New extent is necessary */
605 struct mem_extent *new_ext;
606
607 new_ext = kzalloc(sizeof(struct mem_extent), gfp_mask);
608 if (!new_ext) {
609 free_mem_extents(list);
610 return -ENOMEM;
611 }
612 new_ext->start = zone_start;
613 new_ext->end = zone_end;
614 list_add_tail(&new_ext->hook, &ext->hook);
615 continue;
616 }
617
618 /* Merge this zone's range of PFNs with the existing one */
619 if (zone_start < ext->start)
620 ext->start = zone_start;
621 if (zone_end > ext->end)
622 ext->end = zone_end;
623
624 /* More merging may be possible */
625 cur = ext;
626 list_for_each_entry_safe_continue(cur, aux, list, hook) {
627 if (zone_end < cur->start)
628 break;
629 if (zone_end < cur->end)
630 ext->end = cur->end;
631 list_del(&cur->hook);
632 kfree(cur);
633 }
634 }
635
636 return 0;
637}
638
639/**
640 * memory_bm_create - Allocate memory for a memory bitmap.
641 */
642static int memory_bm_create(struct memory_bitmap *bm, gfp_t gfp_mask,
643 int safe_needed)
644{
645 struct chain_allocator ca;
646 struct list_head mem_extents;
647 struct mem_extent *ext;
648 int error;
649
650 chain_init(&ca, gfp_mask, safe_needed);
651 INIT_LIST_HEAD(&bm->zones);
652
653 error = create_mem_extents(&mem_extents, gfp_mask);
654 if (error)
655 return error;
656
657 list_for_each_entry(ext, &mem_extents, hook) {
658 struct mem_zone_bm_rtree *zone;
659
660 zone = create_zone_bm_rtree(gfp_mask, safe_needed, &ca,
661 ext->start, ext->end);
662 if (!zone) {
663 error = -ENOMEM;
664 goto Error;
665 }
666 list_add_tail(&zone->list, &bm->zones);
667 }
668
669 bm->p_list = ca.chain;
670 memory_bm_position_reset(bm);
671 Exit:
672 free_mem_extents(&mem_extents);
673 return error;
674
675 Error:
676 bm->p_list = ca.chain;
677 memory_bm_free(bm, PG_UNSAFE_CLEAR);
678 goto Exit;
679}
680
681/**
682 * memory_bm_free - Free memory occupied by the memory bitmap.
683 * @bm: Memory bitmap.
684 */
685static void memory_bm_free(struct memory_bitmap *bm, int clear_nosave_free)
686{
687 struct mem_zone_bm_rtree *zone;
688
689 list_for_each_entry(zone, &bm->zones, list)
690 free_zone_bm_rtree(zone, clear_nosave_free);
691
692 free_list_of_pages(bm->p_list, clear_nosave_free);
693
694 INIT_LIST_HEAD(&bm->zones);
695}
696
697/**
698 * memory_bm_find_bit - Find the bit for a given PFN in a memory bitmap.
699 *
700 * Find the bit in memory bitmap @bm that corresponds to the given PFN.
701 * The cur.zone, cur.block and cur.node_pfn members of @bm are updated.
702 *
703 * Walk the radix tree to find the page containing the bit that represents @pfn
704 * and return the position of the bit in @addr and @bit_nr.
705 */
706static int memory_bm_find_bit(struct memory_bitmap *bm, unsigned long pfn,
707 void **addr, unsigned int *bit_nr)
708{
709 struct mem_zone_bm_rtree *curr, *zone;
710 struct rtree_node *node;
711 int i, block_nr;
712
713 zone = bm->cur.zone;
714
715 if (pfn >= zone->start_pfn && pfn < zone->end_pfn)
716 goto zone_found;
717
718 zone = NULL;
719
720 /* Find the right zone */
721 list_for_each_entry(curr, &bm->zones, list) {
722 if (pfn >= curr->start_pfn && pfn < curr->end_pfn) {
723 zone = curr;
724 break;
725 }
726 }
727
728 if (!zone)
729 return -EFAULT;
730
731zone_found:
732 /*
733 * We have found the zone. Now walk the radix tree to find the leaf node
734 * for our PFN.
735 */
736
737 /*
738 * If the zone we wish to scan is the the current zone and the
739 * pfn falls into the current node then we do not need to walk
740 * the tree.
741 */
742 node = bm->cur.node;
743 if (zone == bm->cur.zone &&
744 ((pfn - zone->start_pfn) & ~BM_BLOCK_MASK) == bm->cur.node_pfn)
745 goto node_found;
746
747 node = zone->rtree;
748 block_nr = (pfn - zone->start_pfn) >> BM_BLOCK_SHIFT;
749
750 for (i = zone->levels; i > 0; i--) {
751 int index;
752
753 index = block_nr >> ((i - 1) * BM_RTREE_LEVEL_SHIFT);
754 index &= BM_RTREE_LEVEL_MASK;
755 BUG_ON(node->data[index] == 0);
756 node = (struct rtree_node *)node->data[index];
757 }
758
759node_found:
760 /* Update last position */
761 bm->cur.zone = zone;
762 bm->cur.node = node;
763 bm->cur.node_pfn = (pfn - zone->start_pfn) & ~BM_BLOCK_MASK;
764
765 /* Set return values */
766 *addr = node->data;
767 *bit_nr = (pfn - zone->start_pfn) & BM_BLOCK_MASK;
768
769 return 0;
770}
771
772static void memory_bm_set_bit(struct memory_bitmap *bm, unsigned long pfn)
773{
774 void *addr;
775 unsigned int bit;
776 int error;
777
778 error = memory_bm_find_bit(bm, pfn, &addr, &bit);
779 BUG_ON(error);
780 set_bit(bit, addr);
781}
782
783static int mem_bm_set_bit_check(struct memory_bitmap *bm, unsigned long pfn)
784{
785 void *addr;
786 unsigned int bit;
787 int error;
788
789 error = memory_bm_find_bit(bm, pfn, &addr, &bit);
790 if (!error)
791 set_bit(bit, addr);
792
793 return error;
794}
795
796static void memory_bm_clear_bit(struct memory_bitmap *bm, unsigned long pfn)
797{
798 void *addr;
799 unsigned int bit;
800 int error;
801
802 error = memory_bm_find_bit(bm, pfn, &addr, &bit);
803 BUG_ON(error);
804 clear_bit(bit, addr);
805}
806
807static void memory_bm_clear_current(struct memory_bitmap *bm)
808{
809 int bit;
810
811 bit = max(bm->cur.node_bit - 1, 0);
812 clear_bit(bit, bm->cur.node->data);
813}
814
815static int memory_bm_test_bit(struct memory_bitmap *bm, unsigned long pfn)
816{
817 void *addr;
818 unsigned int bit;
819 int error;
820
821 error = memory_bm_find_bit(bm, pfn, &addr, &bit);
822 BUG_ON(error);
823 return test_bit(bit, addr);
824}
825
826static bool memory_bm_pfn_present(struct memory_bitmap *bm, unsigned long pfn)
827{
828 void *addr;
829 unsigned int bit;
830
831 return !memory_bm_find_bit(bm, pfn, &addr, &bit);
832}
833
834/*
835 * rtree_next_node - Jump to the next leaf node.
836 *
837 * Set the position to the beginning of the next node in the
838 * memory bitmap. This is either the next node in the current
839 * zone's radix tree or the first node in the radix tree of the
840 * next zone.
841 *
842 * Return true if there is a next node, false otherwise.
843 */
844static bool rtree_next_node(struct memory_bitmap *bm)
845{
846 if (!list_is_last(&bm->cur.node->list, &bm->cur.zone->leaves)) {
847 bm->cur.node = list_entry(bm->cur.node->list.next,
848 struct rtree_node, list);
849 bm->cur.node_pfn += BM_BITS_PER_BLOCK;
850 bm->cur.node_bit = 0;
851 touch_softlockup_watchdog();
852 return true;
853 }
854
855 /* No more nodes, goto next zone */
856 if (!list_is_last(&bm->cur.zone->list, &bm->zones)) {
857 bm->cur.zone = list_entry(bm->cur.zone->list.next,
858 struct mem_zone_bm_rtree, list);
859 bm->cur.node = list_entry(bm->cur.zone->leaves.next,
860 struct rtree_node, list);
861 bm->cur.node_pfn = 0;
862 bm->cur.node_bit = 0;
863 return true;
864 }
865
866 /* No more zones */
867 return false;
868}
869
870/**
871 * memory_bm_rtree_next_pfn - Find the next set bit in a memory bitmap.
872 * @bm: Memory bitmap.
873 *
874 * Starting from the last returned position this function searches for the next
875 * set bit in @bm and returns the PFN represented by it. If no more bits are
876 * set, BM_END_OF_MAP is returned.
877 *
878 * It is required to run memory_bm_position_reset() before the first call to
879 * this function for the given memory bitmap.
880 */
881static unsigned long memory_bm_next_pfn(struct memory_bitmap *bm)
882{
883 unsigned long bits, pfn, pages;
884 int bit;
885
886 do {
887 pages = bm->cur.zone->end_pfn - bm->cur.zone->start_pfn;
888 bits = min(pages - bm->cur.node_pfn, BM_BITS_PER_BLOCK);
889 bit = find_next_bit(bm->cur.node->data, bits,
890 bm->cur.node_bit);
891 if (bit < bits) {
892 pfn = bm->cur.zone->start_pfn + bm->cur.node_pfn + bit;
893 bm->cur.node_bit = bit + 1;
894 return pfn;
895 }
896 } while (rtree_next_node(bm));
897
898 return BM_END_OF_MAP;
899}
900
901/*
902 * This structure represents a range of page frames the contents of which
903 * should not be saved during hibernation.
904 */
905struct nosave_region {
906 struct list_head list;
907 unsigned long start_pfn;
908 unsigned long end_pfn;
909};
910
911static LIST_HEAD(nosave_regions);
912
913static void recycle_zone_bm_rtree(struct mem_zone_bm_rtree *zone)
914{
915 struct rtree_node *node;
916
917 list_for_each_entry(node, &zone->nodes, list)
918 recycle_safe_page(node->data);
919
920 list_for_each_entry(node, &zone->leaves, list)
921 recycle_safe_page(node->data);
922}
923
924static void memory_bm_recycle(struct memory_bitmap *bm)
925{
926 struct mem_zone_bm_rtree *zone;
927 struct linked_page *p_list;
928
929 list_for_each_entry(zone, &bm->zones, list)
930 recycle_zone_bm_rtree(zone);
931
932 p_list = bm->p_list;
933 while (p_list) {
934 struct linked_page *lp = p_list;
935
936 p_list = lp->next;
937 recycle_safe_page(lp);
938 }
939}
940
941/**
942 * register_nosave_region - Register a region of unsaveable memory.
943 *
944 * Register a range of page frames the contents of which should not be saved
945 * during hibernation (to be used in the early initialization code).
946 */
947void __init __register_nosave_region(unsigned long start_pfn,
948 unsigned long end_pfn, int use_kmalloc)
949{
950 struct nosave_region *region;
951
952 if (start_pfn >= end_pfn)
953 return;
954
955 if (!list_empty(&nosave_regions)) {
956 /* Try to extend the previous region (they should be sorted) */
957 region = list_entry(nosave_regions.prev,
958 struct nosave_region, list);
959 if (region->end_pfn == start_pfn) {
960 region->end_pfn = end_pfn;
961 goto Report;
962 }
963 }
964 if (use_kmalloc) {
965 /* During init, this shouldn't fail */
966 region = kmalloc(sizeof(struct nosave_region), GFP_KERNEL);
967 BUG_ON(!region);
968 } else {
969 /* This allocation cannot fail */
970 region = memblock_alloc(sizeof(struct nosave_region),
971 SMP_CACHE_BYTES);
972 if (!region)
973 panic("%s: Failed to allocate %zu bytes\n", __func__,
974 sizeof(struct nosave_region));
975 }
976 region->start_pfn = start_pfn;
977 region->end_pfn = end_pfn;
978 list_add_tail(®ion->list, &nosave_regions);
979 Report:
980 pr_info("Registered nosave memory: [mem %#010llx-%#010llx]\n",
981 (unsigned long long) start_pfn << PAGE_SHIFT,
982 ((unsigned long long) end_pfn << PAGE_SHIFT) - 1);
983}
984
985/*
986 * Set bits in this map correspond to the page frames the contents of which
987 * should not be saved during the suspend.
988 */
989static struct memory_bitmap *forbidden_pages_map;
990
991/* Set bits in this map correspond to free page frames. */
992static struct memory_bitmap *free_pages_map;
993
994/*
995 * Each page frame allocated for creating the image is marked by setting the
996 * corresponding bits in forbidden_pages_map and free_pages_map simultaneously
997 */
998
999void swsusp_set_page_free(struct page *page)
1000{
1001 if (free_pages_map)
1002 memory_bm_set_bit(free_pages_map, page_to_pfn(page));
1003}
1004
1005static int swsusp_page_is_free(struct page *page)
1006{
1007 return free_pages_map ?
1008 memory_bm_test_bit(free_pages_map, page_to_pfn(page)) : 0;
1009}
1010
1011void swsusp_unset_page_free(struct page *page)
1012{
1013 if (free_pages_map)
1014 memory_bm_clear_bit(free_pages_map, page_to_pfn(page));
1015}
1016
1017static void swsusp_set_page_forbidden(struct page *page)
1018{
1019 if (forbidden_pages_map)
1020 memory_bm_set_bit(forbidden_pages_map, page_to_pfn(page));
1021}
1022
1023int swsusp_page_is_forbidden(struct page *page)
1024{
1025 return forbidden_pages_map ?
1026 memory_bm_test_bit(forbidden_pages_map, page_to_pfn(page)) : 0;
1027}
1028
1029static void swsusp_unset_page_forbidden(struct page *page)
1030{
1031 if (forbidden_pages_map)
1032 memory_bm_clear_bit(forbidden_pages_map, page_to_pfn(page));
1033}
1034
1035/**
1036 * mark_nosave_pages - Mark pages that should not be saved.
1037 * @bm: Memory bitmap.
1038 *
1039 * Set the bits in @bm that correspond to the page frames the contents of which
1040 * should not be saved.
1041 */
1042static void mark_nosave_pages(struct memory_bitmap *bm)
1043{
1044 struct nosave_region *region;
1045
1046 if (list_empty(&nosave_regions))
1047 return;
1048
1049 list_for_each_entry(region, &nosave_regions, list) {
1050 unsigned long pfn;
1051
1052 pr_debug("Marking nosave pages: [mem %#010llx-%#010llx]\n",
1053 (unsigned long long) region->start_pfn << PAGE_SHIFT,
1054 ((unsigned long long) region->end_pfn << PAGE_SHIFT)
1055 - 1);
1056
1057 for (pfn = region->start_pfn; pfn < region->end_pfn; pfn++)
1058 if (pfn_valid(pfn)) {
1059 /*
1060 * It is safe to ignore the result of
1061 * mem_bm_set_bit_check() here, since we won't
1062 * touch the PFNs for which the error is
1063 * returned anyway.
1064 */
1065 mem_bm_set_bit_check(bm, pfn);
1066 }
1067 }
1068}
1069
1070/**
1071 * create_basic_memory_bitmaps - Create bitmaps to hold basic page information.
1072 *
1073 * Create bitmaps needed for marking page frames that should not be saved and
1074 * free page frames. The forbidden_pages_map and free_pages_map pointers are
1075 * only modified if everything goes well, because we don't want the bits to be
1076 * touched before both bitmaps are set up.
1077 */
1078int create_basic_memory_bitmaps(void)
1079{
1080 struct memory_bitmap *bm1, *bm2;
1081 int error = 0;
1082
1083 if (forbidden_pages_map && free_pages_map)
1084 return 0;
1085 else
1086 BUG_ON(forbidden_pages_map || free_pages_map);
1087
1088 bm1 = kzalloc(sizeof(struct memory_bitmap), GFP_KERNEL);
1089 if (!bm1)
1090 return -ENOMEM;
1091
1092 error = memory_bm_create(bm1, GFP_KERNEL, PG_ANY);
1093 if (error)
1094 goto Free_first_object;
1095
1096 bm2 = kzalloc(sizeof(struct memory_bitmap), GFP_KERNEL);
1097 if (!bm2)
1098 goto Free_first_bitmap;
1099
1100 error = memory_bm_create(bm2, GFP_KERNEL, PG_ANY);
1101 if (error)
1102 goto Free_second_object;
1103
1104 forbidden_pages_map = bm1;
1105 free_pages_map = bm2;
1106 mark_nosave_pages(forbidden_pages_map);
1107
1108 pr_debug("Basic memory bitmaps created\n");
1109
1110 return 0;
1111
1112 Free_second_object:
1113 kfree(bm2);
1114 Free_first_bitmap:
1115 memory_bm_free(bm1, PG_UNSAFE_CLEAR);
1116 Free_first_object:
1117 kfree(bm1);
1118 return -ENOMEM;
1119}
1120
1121/**
1122 * free_basic_memory_bitmaps - Free memory bitmaps holding basic information.
1123 *
1124 * Free memory bitmaps allocated by create_basic_memory_bitmaps(). The
1125 * auxiliary pointers are necessary so that the bitmaps themselves are not
1126 * referred to while they are being freed.
1127 */
1128void free_basic_memory_bitmaps(void)
1129{
1130 struct memory_bitmap *bm1, *bm2;
1131
1132 if (WARN_ON(!(forbidden_pages_map && free_pages_map)))
1133 return;
1134
1135 bm1 = forbidden_pages_map;
1136 bm2 = free_pages_map;
1137 forbidden_pages_map = NULL;
1138 free_pages_map = NULL;
1139 memory_bm_free(bm1, PG_UNSAFE_CLEAR);
1140 kfree(bm1);
1141 memory_bm_free(bm2, PG_UNSAFE_CLEAR);
1142 kfree(bm2);
1143
1144 pr_debug("Basic memory bitmaps freed\n");
1145}
1146
1147void clear_free_pages(void)
1148{
1149 struct memory_bitmap *bm = free_pages_map;
1150 unsigned long pfn;
1151
1152 if (WARN_ON(!(free_pages_map)))
1153 return;
1154
1155 if (IS_ENABLED(CONFIG_PAGE_POISONING_ZERO) || want_init_on_free()) {
1156 memory_bm_position_reset(bm);
1157 pfn = memory_bm_next_pfn(bm);
1158 while (pfn != BM_END_OF_MAP) {
1159 if (pfn_valid(pfn))
1160 clear_highpage(pfn_to_page(pfn));
1161
1162 pfn = memory_bm_next_pfn(bm);
1163 }
1164 memory_bm_position_reset(bm);
1165 pr_info("free pages cleared after restore\n");
1166 }
1167}
1168
1169/**
1170 * snapshot_additional_pages - Estimate the number of extra pages needed.
1171 * @zone: Memory zone to carry out the computation for.
1172 *
1173 * Estimate the number of additional pages needed for setting up a hibernation
1174 * image data structures for @zone (usually, the returned value is greater than
1175 * the exact number).
1176 */
1177unsigned int snapshot_additional_pages(struct zone *zone)
1178{
1179 unsigned int rtree, nodes;
1180
1181 rtree = nodes = DIV_ROUND_UP(zone->spanned_pages, BM_BITS_PER_BLOCK);
1182 rtree += DIV_ROUND_UP(rtree * sizeof(struct rtree_node),
1183 LINKED_PAGE_DATA_SIZE);
1184 while (nodes > 1) {
1185 nodes = DIV_ROUND_UP(nodes, BM_ENTRIES_PER_LEVEL);
1186 rtree += nodes;
1187 }
1188
1189 return 2 * rtree;
1190}
1191
1192#ifdef CONFIG_HIGHMEM
1193/**
1194 * count_free_highmem_pages - Compute the total number of free highmem pages.
1195 *
1196 * The returned number is system-wide.
1197 */
1198static unsigned int count_free_highmem_pages(void)
1199{
1200 struct zone *zone;
1201 unsigned int cnt = 0;
1202
1203 for_each_populated_zone(zone)
1204 if (is_highmem(zone))
1205 cnt += zone_page_state(zone, NR_FREE_PAGES);
1206
1207 return cnt;
1208}
1209
1210/**
1211 * saveable_highmem_page - Check if a highmem page is saveable.
1212 *
1213 * Determine whether a highmem page should be included in a hibernation image.
1214 *
1215 * We should save the page if it isn't Nosave or NosaveFree, or Reserved,
1216 * and it isn't part of a free chunk of pages.
1217 */
1218static struct page *saveable_highmem_page(struct zone *zone, unsigned long pfn)
1219{
1220 struct page *page;
1221
1222 if (!pfn_valid(pfn))
1223 return NULL;
1224
1225 page = pfn_to_online_page(pfn);
1226 if (!page || page_zone(page) != zone)
1227 return NULL;
1228
1229 BUG_ON(!PageHighMem(page));
1230
1231 if (swsusp_page_is_forbidden(page) || swsusp_page_is_free(page))
1232 return NULL;
1233
1234 if (PageReserved(page) || PageOffline(page))
1235 return NULL;
1236
1237 if (page_is_guard(page))
1238 return NULL;
1239
1240 return page;
1241}
1242
1243/**
1244 * count_highmem_pages - Compute the total number of saveable highmem pages.
1245 */
1246static unsigned int count_highmem_pages(void)
1247{
1248 struct zone *zone;
1249 unsigned int n = 0;
1250
1251 for_each_populated_zone(zone) {
1252 unsigned long pfn, max_zone_pfn;
1253
1254 if (!is_highmem(zone))
1255 continue;
1256
1257 mark_free_pages(zone);
1258 max_zone_pfn = zone_end_pfn(zone);
1259 for (pfn = zone->zone_start_pfn; pfn < max_zone_pfn; pfn++)
1260 if (saveable_highmem_page(zone, pfn))
1261 n++;
1262 }
1263 return n;
1264}
1265#else
1266static inline void *saveable_highmem_page(struct zone *z, unsigned long p)
1267{
1268 return NULL;
1269}
1270#endif /* CONFIG_HIGHMEM */
1271
1272/**
1273 * saveable_page - Check if the given page is saveable.
1274 *
1275 * Determine whether a non-highmem page should be included in a hibernation
1276 * image.
1277 *
1278 * We should save the page if it isn't Nosave, and is not in the range
1279 * of pages statically defined as 'unsaveable', and it isn't part of
1280 * a free chunk of pages.
1281 */
1282static struct page *saveable_page(struct zone *zone, unsigned long pfn)
1283{
1284 struct page *page;
1285
1286 if (!pfn_valid(pfn))
1287 return NULL;
1288
1289 page = pfn_to_online_page(pfn);
1290 if (!page || page_zone(page) != zone)
1291 return NULL;
1292
1293 BUG_ON(PageHighMem(page));
1294
1295 if (swsusp_page_is_forbidden(page) || swsusp_page_is_free(page))
1296 return NULL;
1297
1298 if (PageOffline(page))
1299 return NULL;
1300
1301 if (PageReserved(page)
1302 && (!kernel_page_present(page) || pfn_is_nosave(pfn)))
1303 return NULL;
1304
1305 if (page_is_guard(page))
1306 return NULL;
1307
1308 return page;
1309}
1310
1311/**
1312 * count_data_pages - Compute the total number of saveable non-highmem pages.
1313 */
1314static unsigned int count_data_pages(void)
1315{
1316 struct zone *zone;
1317 unsigned long pfn, max_zone_pfn;
1318 unsigned int n = 0;
1319
1320 for_each_populated_zone(zone) {
1321 if (is_highmem(zone))
1322 continue;
1323
1324 mark_free_pages(zone);
1325 max_zone_pfn = zone_end_pfn(zone);
1326 for (pfn = zone->zone_start_pfn; pfn < max_zone_pfn; pfn++)
1327 if (saveable_page(zone, pfn))
1328 n++;
1329 }
1330 return n;
1331}
1332
1333/*
1334 * This is needed, because copy_page and memcpy are not usable for copying
1335 * task structs.
1336 */
1337static inline void do_copy_page(long *dst, long *src)
1338{
1339 int n;
1340
1341 for (n = PAGE_SIZE / sizeof(long); n; n--)
1342 *dst++ = *src++;
1343}
1344
1345/**
1346 * safe_copy_page - Copy a page in a safe way.
1347 *
1348 * Check if the page we are going to copy is marked as present in the kernel
1349 * page tables. This always is the case if CONFIG_DEBUG_PAGEALLOC or
1350 * CONFIG_ARCH_HAS_SET_DIRECT_MAP is not set. In that case kernel_page_present()
1351 * always returns 'true'.
1352 */
1353static void safe_copy_page(void *dst, struct page *s_page)
1354{
1355 if (kernel_page_present(s_page)) {
1356 do_copy_page(dst, page_address(s_page));
1357 } else {
1358 kernel_map_pages(s_page, 1, 1);
1359 do_copy_page(dst, page_address(s_page));
1360 kernel_map_pages(s_page, 1, 0);
1361 }
1362}
1363
1364#ifdef CONFIG_HIGHMEM
1365static inline struct page *page_is_saveable(struct zone *zone, unsigned long pfn)
1366{
1367 return is_highmem(zone) ?
1368 saveable_highmem_page(zone, pfn) : saveable_page(zone, pfn);
1369}
1370
1371static void copy_data_page(unsigned long dst_pfn, unsigned long src_pfn)
1372{
1373 struct page *s_page, *d_page;
1374 void *src, *dst;
1375
1376 s_page = pfn_to_page(src_pfn);
1377 d_page = pfn_to_page(dst_pfn);
1378 if (PageHighMem(s_page)) {
1379 src = kmap_atomic(s_page);
1380 dst = kmap_atomic(d_page);
1381 do_copy_page(dst, src);
1382 kunmap_atomic(dst);
1383 kunmap_atomic(src);
1384 } else {
1385 if (PageHighMem(d_page)) {
1386 /*
1387 * The page pointed to by src may contain some kernel
1388 * data modified by kmap_atomic()
1389 */
1390 safe_copy_page(buffer, s_page);
1391 dst = kmap_atomic(d_page);
1392 copy_page(dst, buffer);
1393 kunmap_atomic(dst);
1394 } else {
1395 safe_copy_page(page_address(d_page), s_page);
1396 }
1397 }
1398}
1399#else
1400#define page_is_saveable(zone, pfn) saveable_page(zone, pfn)
1401
1402static inline void copy_data_page(unsigned long dst_pfn, unsigned long src_pfn)
1403{
1404 safe_copy_page(page_address(pfn_to_page(dst_pfn)),
1405 pfn_to_page(src_pfn));
1406}
1407#endif /* CONFIG_HIGHMEM */
1408
1409static void copy_data_pages(struct memory_bitmap *copy_bm,
1410 struct memory_bitmap *orig_bm)
1411{
1412 struct zone *zone;
1413 unsigned long pfn;
1414
1415 for_each_populated_zone(zone) {
1416 unsigned long max_zone_pfn;
1417
1418 mark_free_pages(zone);
1419 max_zone_pfn = zone_end_pfn(zone);
1420 for (pfn = zone->zone_start_pfn; pfn < max_zone_pfn; pfn++)
1421 if (page_is_saveable(zone, pfn))
1422 memory_bm_set_bit(orig_bm, pfn);
1423 }
1424 memory_bm_position_reset(orig_bm);
1425 memory_bm_position_reset(copy_bm);
1426 for(;;) {
1427 pfn = memory_bm_next_pfn(orig_bm);
1428 if (unlikely(pfn == BM_END_OF_MAP))
1429 break;
1430 copy_data_page(memory_bm_next_pfn(copy_bm), pfn);
1431 }
1432}
1433
1434/* Total number of image pages */
1435static unsigned int nr_copy_pages;
1436/* Number of pages needed for saving the original pfns of the image pages */
1437static unsigned int nr_meta_pages;
1438/*
1439 * Numbers of normal and highmem page frames allocated for hibernation image
1440 * before suspending devices.
1441 */
1442static unsigned int alloc_normal, alloc_highmem;
1443/*
1444 * Memory bitmap used for marking saveable pages (during hibernation) or
1445 * hibernation image pages (during restore)
1446 */
1447static struct memory_bitmap orig_bm;
1448/*
1449 * Memory bitmap used during hibernation for marking allocated page frames that
1450 * will contain copies of saveable pages. During restore it is initially used
1451 * for marking hibernation image pages, but then the set bits from it are
1452 * duplicated in @orig_bm and it is released. On highmem systems it is next
1453 * used for marking "safe" highmem pages, but it has to be reinitialized for
1454 * this purpose.
1455 */
1456static struct memory_bitmap copy_bm;
1457
1458/**
1459 * swsusp_free - Free pages allocated for hibernation image.
1460 *
1461 * Image pages are alocated before snapshot creation, so they need to be
1462 * released after resume.
1463 */
1464void swsusp_free(void)
1465{
1466 unsigned long fb_pfn, fr_pfn;
1467
1468 if (!forbidden_pages_map || !free_pages_map)
1469 goto out;
1470
1471 memory_bm_position_reset(forbidden_pages_map);
1472 memory_bm_position_reset(free_pages_map);
1473
1474loop:
1475 fr_pfn = memory_bm_next_pfn(free_pages_map);
1476 fb_pfn = memory_bm_next_pfn(forbidden_pages_map);
1477
1478 /*
1479 * Find the next bit set in both bitmaps. This is guaranteed to
1480 * terminate when fb_pfn == fr_pfn == BM_END_OF_MAP.
1481 */
1482 do {
1483 if (fb_pfn < fr_pfn)
1484 fb_pfn = memory_bm_next_pfn(forbidden_pages_map);
1485 if (fr_pfn < fb_pfn)
1486 fr_pfn = memory_bm_next_pfn(free_pages_map);
1487 } while (fb_pfn != fr_pfn);
1488
1489 if (fr_pfn != BM_END_OF_MAP && pfn_valid(fr_pfn)) {
1490 struct page *page = pfn_to_page(fr_pfn);
1491
1492 memory_bm_clear_current(forbidden_pages_map);
1493 memory_bm_clear_current(free_pages_map);
1494 hibernate_restore_unprotect_page(page_address(page));
1495 __free_page(page);
1496 goto loop;
1497 }
1498
1499out:
1500 nr_copy_pages = 0;
1501 nr_meta_pages = 0;
1502 restore_pblist = NULL;
1503 buffer = NULL;
1504 alloc_normal = 0;
1505 alloc_highmem = 0;
1506 hibernate_restore_protection_end();
1507}
1508
1509/* Helper functions used for the shrinking of memory. */
1510
1511#define GFP_IMAGE (GFP_KERNEL | __GFP_NOWARN)
1512
1513/**
1514 * preallocate_image_pages - Allocate a number of pages for hibernation image.
1515 * @nr_pages: Number of page frames to allocate.
1516 * @mask: GFP flags to use for the allocation.
1517 *
1518 * Return value: Number of page frames actually allocated
1519 */
1520static unsigned long preallocate_image_pages(unsigned long nr_pages, gfp_t mask)
1521{
1522 unsigned long nr_alloc = 0;
1523
1524 while (nr_pages > 0) {
1525 struct page *page;
1526
1527 page = alloc_image_page(mask);
1528 if (!page)
1529 break;
1530 memory_bm_set_bit(©_bm, page_to_pfn(page));
1531 if (PageHighMem(page))
1532 alloc_highmem++;
1533 else
1534 alloc_normal++;
1535 nr_pages--;
1536 nr_alloc++;
1537 }
1538
1539 return nr_alloc;
1540}
1541
1542static unsigned long preallocate_image_memory(unsigned long nr_pages,
1543 unsigned long avail_normal)
1544{
1545 unsigned long alloc;
1546
1547 if (avail_normal <= alloc_normal)
1548 return 0;
1549
1550 alloc = avail_normal - alloc_normal;
1551 if (nr_pages < alloc)
1552 alloc = nr_pages;
1553
1554 return preallocate_image_pages(alloc, GFP_IMAGE);
1555}
1556
1557#ifdef CONFIG_HIGHMEM
1558static unsigned long preallocate_image_highmem(unsigned long nr_pages)
1559{
1560 return preallocate_image_pages(nr_pages, GFP_IMAGE | __GFP_HIGHMEM);
1561}
1562
1563/**
1564 * __fraction - Compute (an approximation of) x * (multiplier / base).
1565 */
1566static unsigned long __fraction(u64 x, u64 multiplier, u64 base)
1567{
1568 return div64_u64(x * multiplier, base);
1569}
1570
1571static unsigned long preallocate_highmem_fraction(unsigned long nr_pages,
1572 unsigned long highmem,
1573 unsigned long total)
1574{
1575 unsigned long alloc = __fraction(nr_pages, highmem, total);
1576
1577 return preallocate_image_pages(alloc, GFP_IMAGE | __GFP_HIGHMEM);
1578}
1579#else /* CONFIG_HIGHMEM */
1580static inline unsigned long preallocate_image_highmem(unsigned long nr_pages)
1581{
1582 return 0;
1583}
1584
1585static inline unsigned long preallocate_highmem_fraction(unsigned long nr_pages,
1586 unsigned long highmem,
1587 unsigned long total)
1588{
1589 return 0;
1590}
1591#endif /* CONFIG_HIGHMEM */
1592
1593/**
1594 * free_unnecessary_pages - Release preallocated pages not needed for the image.
1595 */
1596static unsigned long free_unnecessary_pages(void)
1597{
1598 unsigned long save, to_free_normal, to_free_highmem, free;
1599
1600 save = count_data_pages();
1601 if (alloc_normal >= save) {
1602 to_free_normal = alloc_normal - save;
1603 save = 0;
1604 } else {
1605 to_free_normal = 0;
1606 save -= alloc_normal;
1607 }
1608 save += count_highmem_pages();
1609 if (alloc_highmem >= save) {
1610 to_free_highmem = alloc_highmem - save;
1611 } else {
1612 to_free_highmem = 0;
1613 save -= alloc_highmem;
1614 if (to_free_normal > save)
1615 to_free_normal -= save;
1616 else
1617 to_free_normal = 0;
1618 }
1619 free = to_free_normal + to_free_highmem;
1620
1621 memory_bm_position_reset(©_bm);
1622
1623 while (to_free_normal > 0 || to_free_highmem > 0) {
1624 unsigned long pfn = memory_bm_next_pfn(©_bm);
1625 struct page *page = pfn_to_page(pfn);
1626
1627 if (PageHighMem(page)) {
1628 if (!to_free_highmem)
1629 continue;
1630 to_free_highmem--;
1631 alloc_highmem--;
1632 } else {
1633 if (!to_free_normal)
1634 continue;
1635 to_free_normal--;
1636 alloc_normal--;
1637 }
1638 memory_bm_clear_bit(©_bm, pfn);
1639 swsusp_unset_page_forbidden(page);
1640 swsusp_unset_page_free(page);
1641 __free_page(page);
1642 }
1643
1644 return free;
1645}
1646
1647/**
1648 * minimum_image_size - Estimate the minimum acceptable size of an image.
1649 * @saveable: Number of saveable pages in the system.
1650 *
1651 * We want to avoid attempting to free too much memory too hard, so estimate the
1652 * minimum acceptable size of a hibernation image to use as the lower limit for
1653 * preallocating memory.
1654 *
1655 * We assume that the minimum image size should be proportional to
1656 *
1657 * [number of saveable pages] - [number of pages that can be freed in theory]
1658 *
1659 * where the second term is the sum of (1) reclaimable slab pages, (2) active
1660 * and (3) inactive anonymous pages, (4) active and (5) inactive file pages.
1661 */
1662static unsigned long minimum_image_size(unsigned long saveable)
1663{
1664 unsigned long size;
1665
1666 size = global_node_page_state_pages(NR_SLAB_RECLAIMABLE_B)
1667 + global_node_page_state(NR_ACTIVE_ANON)
1668 + global_node_page_state(NR_INACTIVE_ANON)
1669 + global_node_page_state(NR_ACTIVE_FILE)
1670 + global_node_page_state(NR_INACTIVE_FILE);
1671
1672 return saveable <= size ? 0 : saveable - size;
1673}
1674
1675/**
1676 * hibernate_preallocate_memory - Preallocate memory for hibernation image.
1677 *
1678 * To create a hibernation image it is necessary to make a copy of every page
1679 * frame in use. We also need a number of page frames to be free during
1680 * hibernation for allocations made while saving the image and for device
1681 * drivers, in case they need to allocate memory from their hibernation
1682 * callbacks (these two numbers are given by PAGES_FOR_IO (which is a rough
1683 * estimate) and reserved_size divided by PAGE_SIZE (which is tunable through
1684 * /sys/power/reserved_size, respectively). To make this happen, we compute the
1685 * total number of available page frames and allocate at least
1686 *
1687 * ([page frames total] + PAGES_FOR_IO + [metadata pages]) / 2
1688 * + 2 * DIV_ROUND_UP(reserved_size, PAGE_SIZE)
1689 *
1690 * of them, which corresponds to the maximum size of a hibernation image.
1691 *
1692 * If image_size is set below the number following from the above formula,
1693 * the preallocation of memory is continued until the total number of saveable
1694 * pages in the system is below the requested image size or the minimum
1695 * acceptable image size returned by minimum_image_size(), whichever is greater.
1696 */
1697int hibernate_preallocate_memory(void)
1698{
1699 struct zone *zone;
1700 unsigned long saveable, size, max_size, count, highmem, pages = 0;
1701 unsigned long alloc, save_highmem, pages_highmem, avail_normal;
1702 ktime_t start, stop;
1703 int error;
1704
1705 pr_info("Preallocating image memory\n");
1706 start = ktime_get();
1707
1708 error = memory_bm_create(&orig_bm, GFP_IMAGE, PG_ANY);
1709 if (error) {
1710 pr_err("Cannot allocate original bitmap\n");
1711 goto err_out;
1712 }
1713
1714 error = memory_bm_create(©_bm, GFP_IMAGE, PG_ANY);
1715 if (error) {
1716 pr_err("Cannot allocate copy bitmap\n");
1717 goto err_out;
1718 }
1719
1720 alloc_normal = 0;
1721 alloc_highmem = 0;
1722
1723 /* Count the number of saveable data pages. */
1724 save_highmem = count_highmem_pages();
1725 saveable = count_data_pages();
1726
1727 /*
1728 * Compute the total number of page frames we can use (count) and the
1729 * number of pages needed for image metadata (size).
1730 */
1731 count = saveable;
1732 saveable += save_highmem;
1733 highmem = save_highmem;
1734 size = 0;
1735 for_each_populated_zone(zone) {
1736 size += snapshot_additional_pages(zone);
1737 if (is_highmem(zone))
1738 highmem += zone_page_state(zone, NR_FREE_PAGES);
1739 else
1740 count += zone_page_state(zone, NR_FREE_PAGES);
1741 }
1742 avail_normal = count;
1743 count += highmem;
1744 count -= totalreserve_pages;
1745
1746 /* Compute the maximum number of saveable pages to leave in memory. */
1747 max_size = (count - (size + PAGES_FOR_IO)) / 2
1748 - 2 * DIV_ROUND_UP(reserved_size, PAGE_SIZE);
1749 /* Compute the desired number of image pages specified by image_size. */
1750 size = DIV_ROUND_UP(image_size, PAGE_SIZE);
1751 if (size > max_size)
1752 size = max_size;
1753 /*
1754 * If the desired number of image pages is at least as large as the
1755 * current number of saveable pages in memory, allocate page frames for
1756 * the image and we're done.
1757 */
1758 if (size >= saveable) {
1759 pages = preallocate_image_highmem(save_highmem);
1760 pages += preallocate_image_memory(saveable - pages, avail_normal);
1761 goto out;
1762 }
1763
1764 /* Estimate the minimum size of the image. */
1765 pages = minimum_image_size(saveable);
1766 /*
1767 * To avoid excessive pressure on the normal zone, leave room in it to
1768 * accommodate an image of the minimum size (unless it's already too
1769 * small, in which case don't preallocate pages from it at all).
1770 */
1771 if (avail_normal > pages)
1772 avail_normal -= pages;
1773 else
1774 avail_normal = 0;
1775 if (size < pages)
1776 size = min_t(unsigned long, pages, max_size);
1777
1778 /*
1779 * Let the memory management subsystem know that we're going to need a
1780 * large number of page frames to allocate and make it free some memory.
1781 * NOTE: If this is not done, performance will be hurt badly in some
1782 * test cases.
1783 */
1784 shrink_all_memory(saveable - size);
1785
1786 /*
1787 * The number of saveable pages in memory was too high, so apply some
1788 * pressure to decrease it. First, make room for the largest possible
1789 * image and fail if that doesn't work. Next, try to decrease the size
1790 * of the image as much as indicated by 'size' using allocations from
1791 * highmem and non-highmem zones separately.
1792 */
1793 pages_highmem = preallocate_image_highmem(highmem / 2);
1794 alloc = count - max_size;
1795 if (alloc > pages_highmem)
1796 alloc -= pages_highmem;
1797 else
1798 alloc = 0;
1799 pages = preallocate_image_memory(alloc, avail_normal);
1800 if (pages < alloc) {
1801 /* We have exhausted non-highmem pages, try highmem. */
1802 alloc -= pages;
1803 pages += pages_highmem;
1804 pages_highmem = preallocate_image_highmem(alloc);
1805 if (pages_highmem < alloc) {
1806 pr_err("Image allocation is %lu pages short\n",
1807 alloc - pages_highmem);
1808 goto err_out;
1809 }
1810 pages += pages_highmem;
1811 /*
1812 * size is the desired number of saveable pages to leave in
1813 * memory, so try to preallocate (all memory - size) pages.
1814 */
1815 alloc = (count - pages) - size;
1816 pages += preallocate_image_highmem(alloc);
1817 } else {
1818 /*
1819 * There are approximately max_size saveable pages at this point
1820 * and we want to reduce this number down to size.
1821 */
1822 alloc = max_size - size;
1823 size = preallocate_highmem_fraction(alloc, highmem, count);
1824 pages_highmem += size;
1825 alloc -= size;
1826 size = preallocate_image_memory(alloc, avail_normal);
1827 pages_highmem += preallocate_image_highmem(alloc - size);
1828 pages += pages_highmem + size;
1829 }
1830
1831 /*
1832 * We only need as many page frames for the image as there are saveable
1833 * pages in memory, but we have allocated more. Release the excessive
1834 * ones now.
1835 */
1836 pages -= free_unnecessary_pages();
1837
1838 out:
1839 stop = ktime_get();
1840 pr_info("Allocated %lu pages for snapshot\n", pages);
1841 swsusp_show_speed(start, stop, pages, "Allocated");
1842
1843 return 0;
1844
1845 err_out:
1846 swsusp_free();
1847 return -ENOMEM;
1848}
1849
1850#ifdef CONFIG_HIGHMEM
1851/**
1852 * count_pages_for_highmem - Count non-highmem pages needed for copying highmem.
1853 *
1854 * Compute the number of non-highmem pages that will be necessary for creating
1855 * copies of highmem pages.
1856 */
1857static unsigned int count_pages_for_highmem(unsigned int nr_highmem)
1858{
1859 unsigned int free_highmem = count_free_highmem_pages() + alloc_highmem;
1860
1861 if (free_highmem >= nr_highmem)
1862 nr_highmem = 0;
1863 else
1864 nr_highmem -= free_highmem;
1865
1866 return nr_highmem;
1867}
1868#else
1869static unsigned int count_pages_for_highmem(unsigned int nr_highmem) { return 0; }
1870#endif /* CONFIG_HIGHMEM */
1871
1872/**
1873 * enough_free_mem - Check if there is enough free memory for the image.
1874 */
1875static int enough_free_mem(unsigned int nr_pages, unsigned int nr_highmem)
1876{
1877 struct zone *zone;
1878 unsigned int free = alloc_normal;
1879
1880 for_each_populated_zone(zone)
1881 if (!is_highmem(zone))
1882 free += zone_page_state(zone, NR_FREE_PAGES);
1883
1884 nr_pages += count_pages_for_highmem(nr_highmem);
1885 pr_debug("Normal pages needed: %u + %u, available pages: %u\n",
1886 nr_pages, PAGES_FOR_IO, free);
1887
1888 return free > nr_pages + PAGES_FOR_IO;
1889}
1890
1891#ifdef CONFIG_HIGHMEM
1892/**
1893 * get_highmem_buffer - Allocate a buffer for highmem pages.
1894 *
1895 * If there are some highmem pages in the hibernation image, we may need a
1896 * buffer to copy them and/or load their data.
1897 */
1898static inline int get_highmem_buffer(int safe_needed)
1899{
1900 buffer = get_image_page(GFP_ATOMIC, safe_needed);
1901 return buffer ? 0 : -ENOMEM;
1902}
1903
1904/**
1905 * alloc_highmem_image_pages - Allocate some highmem pages for the image.
1906 *
1907 * Try to allocate as many pages as needed, but if the number of free highmem
1908 * pages is less than that, allocate them all.
1909 */
1910static inline unsigned int alloc_highmem_pages(struct memory_bitmap *bm,
1911 unsigned int nr_highmem)
1912{
1913 unsigned int to_alloc = count_free_highmem_pages();
1914
1915 if (to_alloc > nr_highmem)
1916 to_alloc = nr_highmem;
1917
1918 nr_highmem -= to_alloc;
1919 while (to_alloc-- > 0) {
1920 struct page *page;
1921
1922 page = alloc_image_page(__GFP_HIGHMEM|__GFP_KSWAPD_RECLAIM);
1923 memory_bm_set_bit(bm, page_to_pfn(page));
1924 }
1925 return nr_highmem;
1926}
1927#else
1928static inline int get_highmem_buffer(int safe_needed) { return 0; }
1929
1930static inline unsigned int alloc_highmem_pages(struct memory_bitmap *bm,
1931 unsigned int n) { return 0; }
1932#endif /* CONFIG_HIGHMEM */
1933
1934/**
1935 * swsusp_alloc - Allocate memory for hibernation image.
1936 *
1937 * We first try to allocate as many highmem pages as there are
1938 * saveable highmem pages in the system. If that fails, we allocate
1939 * non-highmem pages for the copies of the remaining highmem ones.
1940 *
1941 * In this approach it is likely that the copies of highmem pages will
1942 * also be located in the high memory, because of the way in which
1943 * copy_data_pages() works.
1944 */
1945static int swsusp_alloc(struct memory_bitmap *copy_bm,
1946 unsigned int nr_pages, unsigned int nr_highmem)
1947{
1948 if (nr_highmem > 0) {
1949 if (get_highmem_buffer(PG_ANY))
1950 goto err_out;
1951 if (nr_highmem > alloc_highmem) {
1952 nr_highmem -= alloc_highmem;
1953 nr_pages += alloc_highmem_pages(copy_bm, nr_highmem);
1954 }
1955 }
1956 if (nr_pages > alloc_normal) {
1957 nr_pages -= alloc_normal;
1958 while (nr_pages-- > 0) {
1959 struct page *page;
1960
1961 page = alloc_image_page(GFP_ATOMIC);
1962 if (!page)
1963 goto err_out;
1964 memory_bm_set_bit(copy_bm, page_to_pfn(page));
1965 }
1966 }
1967
1968 return 0;
1969
1970 err_out:
1971 swsusp_free();
1972 return -ENOMEM;
1973}
1974
1975asmlinkage __visible int swsusp_save(void)
1976{
1977 unsigned int nr_pages, nr_highmem;
1978
1979 pr_info("Creating image:\n");
1980
1981 drain_local_pages(NULL);
1982 nr_pages = count_data_pages();
1983 nr_highmem = count_highmem_pages();
1984 pr_info("Need to copy %u pages\n", nr_pages + nr_highmem);
1985
1986 if (!enough_free_mem(nr_pages, nr_highmem)) {
1987 pr_err("Not enough free memory\n");
1988 return -ENOMEM;
1989 }
1990
1991 if (swsusp_alloc(©_bm, nr_pages, nr_highmem)) {
1992 pr_err("Memory allocation failed\n");
1993 return -ENOMEM;
1994 }
1995
1996 /*
1997 * During allocating of suspend pagedir, new cold pages may appear.
1998 * Kill them.
1999 */
2000 drain_local_pages(NULL);
2001 copy_data_pages(©_bm, &orig_bm);
2002
2003 /*
2004 * End of critical section. From now on, we can write to memory,
2005 * but we should not touch disk. This specially means we must _not_
2006 * touch swap space! Except we must write out our image of course.
2007 */
2008
2009 nr_pages += nr_highmem;
2010 nr_copy_pages = nr_pages;
2011 nr_meta_pages = DIV_ROUND_UP(nr_pages * sizeof(long), PAGE_SIZE);
2012
2013 pr_info("Image created (%d pages copied)\n", nr_pages);
2014
2015 return 0;
2016}
2017
2018#ifndef CONFIG_ARCH_HIBERNATION_HEADER
2019static int init_header_complete(struct swsusp_info *info)
2020{
2021 memcpy(&info->uts, init_utsname(), sizeof(struct new_utsname));
2022 info->version_code = LINUX_VERSION_CODE;
2023 return 0;
2024}
2025
2026static const char *check_image_kernel(struct swsusp_info *info)
2027{
2028 if (info->version_code != LINUX_VERSION_CODE)
2029 return "kernel version";
2030 if (strcmp(info->uts.sysname,init_utsname()->sysname))
2031 return "system type";
2032 if (strcmp(info->uts.release,init_utsname()->release))
2033 return "kernel release";
2034 if (strcmp(info->uts.version,init_utsname()->version))
2035 return "version";
2036 if (strcmp(info->uts.machine,init_utsname()->machine))
2037 return "machine";
2038 return NULL;
2039}
2040#endif /* CONFIG_ARCH_HIBERNATION_HEADER */
2041
2042unsigned long snapshot_get_image_size(void)
2043{
2044 return nr_copy_pages + nr_meta_pages + 1;
2045}
2046
2047static int init_header(struct swsusp_info *info)
2048{
2049 memset(info, 0, sizeof(struct swsusp_info));
2050 info->num_physpages = get_num_physpages();
2051 info->image_pages = nr_copy_pages;
2052 info->pages = snapshot_get_image_size();
2053 info->size = info->pages;
2054 info->size <<= PAGE_SHIFT;
2055 return init_header_complete(info);
2056}
2057
2058/**
2059 * pack_pfns - Prepare PFNs for saving.
2060 * @bm: Memory bitmap.
2061 * @buf: Memory buffer to store the PFNs in.
2062 *
2063 * PFNs corresponding to set bits in @bm are stored in the area of memory
2064 * pointed to by @buf (1 page at a time).
2065 */
2066static inline void pack_pfns(unsigned long *buf, struct memory_bitmap *bm)
2067{
2068 int j;
2069
2070 for (j = 0; j < PAGE_SIZE / sizeof(long); j++) {
2071 buf[j] = memory_bm_next_pfn(bm);
2072 if (unlikely(buf[j] == BM_END_OF_MAP))
2073 break;
2074 }
2075}
2076
2077/**
2078 * snapshot_read_next - Get the address to read the next image page from.
2079 * @handle: Snapshot handle to be used for the reading.
2080 *
2081 * On the first call, @handle should point to a zeroed snapshot_handle
2082 * structure. The structure gets populated then and a pointer to it should be
2083 * passed to this function every next time.
2084 *
2085 * On success, the function returns a positive number. Then, the caller
2086 * is allowed to read up to the returned number of bytes from the memory
2087 * location computed by the data_of() macro.
2088 *
2089 * The function returns 0 to indicate the end of the data stream condition,
2090 * and negative numbers are returned on errors. If that happens, the structure
2091 * pointed to by @handle is not updated and should not be used any more.
2092 */
2093int snapshot_read_next(struct snapshot_handle *handle)
2094{
2095 if (handle->cur > nr_meta_pages + nr_copy_pages)
2096 return 0;
2097
2098 if (!buffer) {
2099 /* This makes the buffer be freed by swsusp_free() */
2100 buffer = get_image_page(GFP_ATOMIC, PG_ANY);
2101 if (!buffer)
2102 return -ENOMEM;
2103 }
2104 if (!handle->cur) {
2105 int error;
2106
2107 error = init_header((struct swsusp_info *)buffer);
2108 if (error)
2109 return error;
2110 handle->buffer = buffer;
2111 memory_bm_position_reset(&orig_bm);
2112 memory_bm_position_reset(©_bm);
2113 } else if (handle->cur <= nr_meta_pages) {
2114 clear_page(buffer);
2115 pack_pfns(buffer, &orig_bm);
2116 } else {
2117 struct page *page;
2118
2119 page = pfn_to_page(memory_bm_next_pfn(©_bm));
2120 if (PageHighMem(page)) {
2121 /*
2122 * Highmem pages are copied to the buffer,
2123 * because we can't return with a kmapped
2124 * highmem page (we may not be called again).
2125 */
2126 void *kaddr;
2127
2128 kaddr = kmap_atomic(page);
2129 copy_page(buffer, kaddr);
2130 kunmap_atomic(kaddr);
2131 handle->buffer = buffer;
2132 } else {
2133 handle->buffer = page_address(page);
2134 }
2135 }
2136 handle->cur++;
2137 return PAGE_SIZE;
2138}
2139
2140static void duplicate_memory_bitmap(struct memory_bitmap *dst,
2141 struct memory_bitmap *src)
2142{
2143 unsigned long pfn;
2144
2145 memory_bm_position_reset(src);
2146 pfn = memory_bm_next_pfn(src);
2147 while (pfn != BM_END_OF_MAP) {
2148 memory_bm_set_bit(dst, pfn);
2149 pfn = memory_bm_next_pfn(src);
2150 }
2151}
2152
2153/**
2154 * mark_unsafe_pages - Mark pages that were used before hibernation.
2155 *
2156 * Mark the pages that cannot be used for storing the image during restoration,
2157 * because they conflict with the pages that had been used before hibernation.
2158 */
2159static void mark_unsafe_pages(struct memory_bitmap *bm)
2160{
2161 unsigned long pfn;
2162
2163 /* Clear the "free"/"unsafe" bit for all PFNs */
2164 memory_bm_position_reset(free_pages_map);
2165 pfn = memory_bm_next_pfn(free_pages_map);
2166 while (pfn != BM_END_OF_MAP) {
2167 memory_bm_clear_current(free_pages_map);
2168 pfn = memory_bm_next_pfn(free_pages_map);
2169 }
2170
2171 /* Mark pages that correspond to the "original" PFNs as "unsafe" */
2172 duplicate_memory_bitmap(free_pages_map, bm);
2173
2174 allocated_unsafe_pages = 0;
2175}
2176
2177static int check_header(struct swsusp_info *info)
2178{
2179 const char *reason;
2180
2181 reason = check_image_kernel(info);
2182 if (!reason && info->num_physpages != get_num_physpages())
2183 reason = "memory size";
2184 if (reason) {
2185 pr_err("Image mismatch: %s\n", reason);
2186 return -EPERM;
2187 }
2188 return 0;
2189}
2190
2191/**
2192 * load header - Check the image header and copy the data from it.
2193 */
2194static int load_header(struct swsusp_info *info)
2195{
2196 int error;
2197
2198 restore_pblist = NULL;
2199 error = check_header(info);
2200 if (!error) {
2201 nr_copy_pages = info->image_pages;
2202 nr_meta_pages = info->pages - info->image_pages - 1;
2203 }
2204 return error;
2205}
2206
2207/**
2208 * unpack_orig_pfns - Set bits corresponding to given PFNs in a memory bitmap.
2209 * @bm: Memory bitmap.
2210 * @buf: Area of memory containing the PFNs.
2211 *
2212 * For each element of the array pointed to by @buf (1 page at a time), set the
2213 * corresponding bit in @bm.
2214 */
2215static int unpack_orig_pfns(unsigned long *buf, struct memory_bitmap *bm)
2216{
2217 int j;
2218
2219 for (j = 0; j < PAGE_SIZE / sizeof(long); j++) {
2220 if (unlikely(buf[j] == BM_END_OF_MAP))
2221 break;
2222
2223 if (pfn_valid(buf[j]) && memory_bm_pfn_present(bm, buf[j]))
2224 memory_bm_set_bit(bm, buf[j]);
2225 else
2226 return -EFAULT;
2227 }
2228
2229 return 0;
2230}
2231
2232#ifdef CONFIG_HIGHMEM
2233/*
2234 * struct highmem_pbe is used for creating the list of highmem pages that
2235 * should be restored atomically during the resume from disk, because the page
2236 * frames they have occupied before the suspend are in use.
2237 */
2238struct highmem_pbe {
2239 struct page *copy_page; /* data is here now */
2240 struct page *orig_page; /* data was here before the suspend */
2241 struct highmem_pbe *next;
2242};
2243
2244/*
2245 * List of highmem PBEs needed for restoring the highmem pages that were
2246 * allocated before the suspend and included in the suspend image, but have
2247 * also been allocated by the "resume" kernel, so their contents cannot be
2248 * written directly to their "original" page frames.
2249 */
2250static struct highmem_pbe *highmem_pblist;
2251
2252/**
2253 * count_highmem_image_pages - Compute the number of highmem pages in the image.
2254 * @bm: Memory bitmap.
2255 *
2256 * The bits in @bm that correspond to image pages are assumed to be set.
2257 */
2258static unsigned int count_highmem_image_pages(struct memory_bitmap *bm)
2259{
2260 unsigned long pfn;
2261 unsigned int cnt = 0;
2262
2263 memory_bm_position_reset(bm);
2264 pfn = memory_bm_next_pfn(bm);
2265 while (pfn != BM_END_OF_MAP) {
2266 if (PageHighMem(pfn_to_page(pfn)))
2267 cnt++;
2268
2269 pfn = memory_bm_next_pfn(bm);
2270 }
2271 return cnt;
2272}
2273
2274static unsigned int safe_highmem_pages;
2275
2276static struct memory_bitmap *safe_highmem_bm;
2277
2278/**
2279 * prepare_highmem_image - Allocate memory for loading highmem data from image.
2280 * @bm: Pointer to an uninitialized memory bitmap structure.
2281 * @nr_highmem_p: Pointer to the number of highmem image pages.
2282 *
2283 * Try to allocate as many highmem pages as there are highmem image pages
2284 * (@nr_highmem_p points to the variable containing the number of highmem image
2285 * pages). The pages that are "safe" (ie. will not be overwritten when the
2286 * hibernation image is restored entirely) have the corresponding bits set in
2287 * @bm (it must be unitialized).
2288 *
2289 * NOTE: This function should not be called if there are no highmem image pages.
2290 */
2291static int prepare_highmem_image(struct memory_bitmap *bm,
2292 unsigned int *nr_highmem_p)
2293{
2294 unsigned int to_alloc;
2295
2296 if (memory_bm_create(bm, GFP_ATOMIC, PG_SAFE))
2297 return -ENOMEM;
2298
2299 if (get_highmem_buffer(PG_SAFE))
2300 return -ENOMEM;
2301
2302 to_alloc = count_free_highmem_pages();
2303 if (to_alloc > *nr_highmem_p)
2304 to_alloc = *nr_highmem_p;
2305 else
2306 *nr_highmem_p = to_alloc;
2307
2308 safe_highmem_pages = 0;
2309 while (to_alloc-- > 0) {
2310 struct page *page;
2311
2312 page = alloc_page(__GFP_HIGHMEM);
2313 if (!swsusp_page_is_free(page)) {
2314 /* The page is "safe", set its bit the bitmap */
2315 memory_bm_set_bit(bm, page_to_pfn(page));
2316 safe_highmem_pages++;
2317 }
2318 /* Mark the page as allocated */
2319 swsusp_set_page_forbidden(page);
2320 swsusp_set_page_free(page);
2321 }
2322 memory_bm_position_reset(bm);
2323 safe_highmem_bm = bm;
2324 return 0;
2325}
2326
2327static struct page *last_highmem_page;
2328
2329/**
2330 * get_highmem_page_buffer - Prepare a buffer to store a highmem image page.
2331 *
2332 * For a given highmem image page get a buffer that suspend_write_next() should
2333 * return to its caller to write to.
2334 *
2335 * If the page is to be saved to its "original" page frame or a copy of
2336 * the page is to be made in the highmem, @buffer is returned. Otherwise,
2337 * the copy of the page is to be made in normal memory, so the address of
2338 * the copy is returned.
2339 *
2340 * If @buffer is returned, the caller of suspend_write_next() will write
2341 * the page's contents to @buffer, so they will have to be copied to the
2342 * right location on the next call to suspend_write_next() and it is done
2343 * with the help of copy_last_highmem_page(). For this purpose, if
2344 * @buffer is returned, @last_highmem_page is set to the page to which
2345 * the data will have to be copied from @buffer.
2346 */
2347static void *get_highmem_page_buffer(struct page *page,
2348 struct chain_allocator *ca)
2349{
2350 struct highmem_pbe *pbe;
2351 void *kaddr;
2352
2353 if (swsusp_page_is_forbidden(page) && swsusp_page_is_free(page)) {
2354 /*
2355 * We have allocated the "original" page frame and we can
2356 * use it directly to store the loaded page.
2357 */
2358 last_highmem_page = page;
2359 return buffer;
2360 }
2361 /*
2362 * The "original" page frame has not been allocated and we have to
2363 * use a "safe" page frame to store the loaded page.
2364 */
2365 pbe = chain_alloc(ca, sizeof(struct highmem_pbe));
2366 if (!pbe) {
2367 swsusp_free();
2368 return ERR_PTR(-ENOMEM);
2369 }
2370 pbe->orig_page = page;
2371 if (safe_highmem_pages > 0) {
2372 struct page *tmp;
2373
2374 /* Copy of the page will be stored in high memory */
2375 kaddr = buffer;
2376 tmp = pfn_to_page(memory_bm_next_pfn(safe_highmem_bm));
2377 safe_highmem_pages--;
2378 last_highmem_page = tmp;
2379 pbe->copy_page = tmp;
2380 } else {
2381 /* Copy of the page will be stored in normal memory */
2382 kaddr = safe_pages_list;
2383 safe_pages_list = safe_pages_list->next;
2384 pbe->copy_page = virt_to_page(kaddr);
2385 }
2386 pbe->next = highmem_pblist;
2387 highmem_pblist = pbe;
2388 return kaddr;
2389}
2390
2391/**
2392 * copy_last_highmem_page - Copy most the most recent highmem image page.
2393 *
2394 * Copy the contents of a highmem image from @buffer, where the caller of
2395 * snapshot_write_next() has stored them, to the right location represented by
2396 * @last_highmem_page .
2397 */
2398static void copy_last_highmem_page(void)
2399{
2400 if (last_highmem_page) {
2401 void *dst;
2402
2403 dst = kmap_atomic(last_highmem_page);
2404 copy_page(dst, buffer);
2405 kunmap_atomic(dst);
2406 last_highmem_page = NULL;
2407 }
2408}
2409
2410static inline int last_highmem_page_copied(void)
2411{
2412 return !last_highmem_page;
2413}
2414
2415static inline void free_highmem_data(void)
2416{
2417 if (safe_highmem_bm)
2418 memory_bm_free(safe_highmem_bm, PG_UNSAFE_CLEAR);
2419
2420 if (buffer)
2421 free_image_page(buffer, PG_UNSAFE_CLEAR);
2422}
2423#else
2424static unsigned int count_highmem_image_pages(struct memory_bitmap *bm) { return 0; }
2425
2426static inline int prepare_highmem_image(struct memory_bitmap *bm,
2427 unsigned int *nr_highmem_p) { return 0; }
2428
2429static inline void *get_highmem_page_buffer(struct page *page,
2430 struct chain_allocator *ca)
2431{
2432 return ERR_PTR(-EINVAL);
2433}
2434
2435static inline void copy_last_highmem_page(void) {}
2436static inline int last_highmem_page_copied(void) { return 1; }
2437static inline void free_highmem_data(void) {}
2438#endif /* CONFIG_HIGHMEM */
2439
2440#define PBES_PER_LINKED_PAGE (LINKED_PAGE_DATA_SIZE / sizeof(struct pbe))
2441
2442/**
2443 * prepare_image - Make room for loading hibernation image.
2444 * @new_bm: Unitialized memory bitmap structure.
2445 * @bm: Memory bitmap with unsafe pages marked.
2446 *
2447 * Use @bm to mark the pages that will be overwritten in the process of
2448 * restoring the system memory state from the suspend image ("unsafe" pages)
2449 * and allocate memory for the image.
2450 *
2451 * The idea is to allocate a new memory bitmap first and then allocate
2452 * as many pages as needed for image data, but without specifying what those
2453 * pages will be used for just yet. Instead, we mark them all as allocated and
2454 * create a lists of "safe" pages to be used later. On systems with high
2455 * memory a list of "safe" highmem pages is created too.
2456 */
2457static int prepare_image(struct memory_bitmap *new_bm, struct memory_bitmap *bm)
2458{
2459 unsigned int nr_pages, nr_highmem;
2460 struct linked_page *lp;
2461 int error;
2462
2463 /* If there is no highmem, the buffer will not be necessary */
2464 free_image_page(buffer, PG_UNSAFE_CLEAR);
2465 buffer = NULL;
2466
2467 nr_highmem = count_highmem_image_pages(bm);
2468 mark_unsafe_pages(bm);
2469
2470 error = memory_bm_create(new_bm, GFP_ATOMIC, PG_SAFE);
2471 if (error)
2472 goto Free;
2473
2474 duplicate_memory_bitmap(new_bm, bm);
2475 memory_bm_free(bm, PG_UNSAFE_KEEP);
2476 if (nr_highmem > 0) {
2477 error = prepare_highmem_image(bm, &nr_highmem);
2478 if (error)
2479 goto Free;
2480 }
2481 /*
2482 * Reserve some safe pages for potential later use.
2483 *
2484 * NOTE: This way we make sure there will be enough safe pages for the
2485 * chain_alloc() in get_buffer(). It is a bit wasteful, but
2486 * nr_copy_pages cannot be greater than 50% of the memory anyway.
2487 *
2488 * nr_copy_pages cannot be less than allocated_unsafe_pages too.
2489 */
2490 nr_pages = nr_copy_pages - nr_highmem - allocated_unsafe_pages;
2491 nr_pages = DIV_ROUND_UP(nr_pages, PBES_PER_LINKED_PAGE);
2492 while (nr_pages > 0) {
2493 lp = get_image_page(GFP_ATOMIC, PG_SAFE);
2494 if (!lp) {
2495 error = -ENOMEM;
2496 goto Free;
2497 }
2498 lp->next = safe_pages_list;
2499 safe_pages_list = lp;
2500 nr_pages--;
2501 }
2502 /* Preallocate memory for the image */
2503 nr_pages = nr_copy_pages - nr_highmem - allocated_unsafe_pages;
2504 while (nr_pages > 0) {
2505 lp = (struct linked_page *)get_zeroed_page(GFP_ATOMIC);
2506 if (!lp) {
2507 error = -ENOMEM;
2508 goto Free;
2509 }
2510 if (!swsusp_page_is_free(virt_to_page(lp))) {
2511 /* The page is "safe", add it to the list */
2512 lp->next = safe_pages_list;
2513 safe_pages_list = lp;
2514 }
2515 /* Mark the page as allocated */
2516 swsusp_set_page_forbidden(virt_to_page(lp));
2517 swsusp_set_page_free(virt_to_page(lp));
2518 nr_pages--;
2519 }
2520 return 0;
2521
2522 Free:
2523 swsusp_free();
2524 return error;
2525}
2526
2527/**
2528 * get_buffer - Get the address to store the next image data page.
2529 *
2530 * Get the address that snapshot_write_next() should return to its caller to
2531 * write to.
2532 */
2533static void *get_buffer(struct memory_bitmap *bm, struct chain_allocator *ca)
2534{
2535 struct pbe *pbe;
2536 struct page *page;
2537 unsigned long pfn = memory_bm_next_pfn(bm);
2538
2539 if (pfn == BM_END_OF_MAP)
2540 return ERR_PTR(-EFAULT);
2541
2542 page = pfn_to_page(pfn);
2543 if (PageHighMem(page))
2544 return get_highmem_page_buffer(page, ca);
2545
2546 if (swsusp_page_is_forbidden(page) && swsusp_page_is_free(page))
2547 /*
2548 * We have allocated the "original" page frame and we can
2549 * use it directly to store the loaded page.
2550 */
2551 return page_address(page);
2552
2553 /*
2554 * The "original" page frame has not been allocated and we have to
2555 * use a "safe" page frame to store the loaded page.
2556 */
2557 pbe = chain_alloc(ca, sizeof(struct pbe));
2558 if (!pbe) {
2559 swsusp_free();
2560 return ERR_PTR(-ENOMEM);
2561 }
2562 pbe->orig_address = page_address(page);
2563 pbe->address = safe_pages_list;
2564 safe_pages_list = safe_pages_list->next;
2565 pbe->next = restore_pblist;
2566 restore_pblist = pbe;
2567 return pbe->address;
2568}
2569
2570/**
2571 * snapshot_write_next - Get the address to store the next image page.
2572 * @handle: Snapshot handle structure to guide the writing.
2573 *
2574 * On the first call, @handle should point to a zeroed snapshot_handle
2575 * structure. The structure gets populated then and a pointer to it should be
2576 * passed to this function every next time.
2577 *
2578 * On success, the function returns a positive number. Then, the caller
2579 * is allowed to write up to the returned number of bytes to the memory
2580 * location computed by the data_of() macro.
2581 *
2582 * The function returns 0 to indicate the "end of file" condition. Negative
2583 * numbers are returned on errors, in which cases the structure pointed to by
2584 * @handle is not updated and should not be used any more.
2585 */
2586int snapshot_write_next(struct snapshot_handle *handle)
2587{
2588 static struct chain_allocator ca;
2589 int error = 0;
2590
2591 /* Check if we have already loaded the entire image */
2592 if (handle->cur > 1 && handle->cur > nr_meta_pages + nr_copy_pages)
2593 return 0;
2594
2595 handle->sync_read = 1;
2596
2597 if (!handle->cur) {
2598 if (!buffer)
2599 /* This makes the buffer be freed by swsusp_free() */
2600 buffer = get_image_page(GFP_ATOMIC, PG_ANY);
2601
2602 if (!buffer)
2603 return -ENOMEM;
2604
2605 handle->buffer = buffer;
2606 } else if (handle->cur == 1) {
2607 error = load_header(buffer);
2608 if (error)
2609 return error;
2610
2611 safe_pages_list = NULL;
2612
2613 error = memory_bm_create(©_bm, GFP_ATOMIC, PG_ANY);
2614 if (error)
2615 return error;
2616
2617 hibernate_restore_protection_begin();
2618 } else if (handle->cur <= nr_meta_pages + 1) {
2619 error = unpack_orig_pfns(buffer, ©_bm);
2620 if (error)
2621 return error;
2622
2623 if (handle->cur == nr_meta_pages + 1) {
2624 error = prepare_image(&orig_bm, ©_bm);
2625 if (error)
2626 return error;
2627
2628 chain_init(&ca, GFP_ATOMIC, PG_SAFE);
2629 memory_bm_position_reset(&orig_bm);
2630 restore_pblist = NULL;
2631 handle->buffer = get_buffer(&orig_bm, &ca);
2632 handle->sync_read = 0;
2633 if (IS_ERR(handle->buffer))
2634 return PTR_ERR(handle->buffer);
2635 }
2636 } else {
2637 copy_last_highmem_page();
2638 hibernate_restore_protect_page(handle->buffer);
2639 handle->buffer = get_buffer(&orig_bm, &ca);
2640 if (IS_ERR(handle->buffer))
2641 return PTR_ERR(handle->buffer);
2642 if (handle->buffer != buffer)
2643 handle->sync_read = 0;
2644 }
2645 handle->cur++;
2646 return PAGE_SIZE;
2647}
2648
2649/**
2650 * snapshot_write_finalize - Complete the loading of a hibernation image.
2651 *
2652 * Must be called after the last call to snapshot_write_next() in case the last
2653 * page in the image happens to be a highmem page and its contents should be
2654 * stored in highmem. Additionally, it recycles bitmap memory that's not
2655 * necessary any more.
2656 */
2657void snapshot_write_finalize(struct snapshot_handle *handle)
2658{
2659 copy_last_highmem_page();
2660 hibernate_restore_protect_page(handle->buffer);
2661 /* Do that only if we have loaded the image entirely */
2662 if (handle->cur > 1 && handle->cur > nr_meta_pages + nr_copy_pages) {
2663 memory_bm_recycle(&orig_bm);
2664 free_highmem_data();
2665 }
2666}
2667
2668int snapshot_image_loaded(struct snapshot_handle *handle)
2669{
2670 return !(!nr_copy_pages || !last_highmem_page_copied() ||
2671 handle->cur <= nr_meta_pages + nr_copy_pages);
2672}
2673
2674#ifdef CONFIG_HIGHMEM
2675/* Assumes that @buf is ready and points to a "safe" page */
2676static inline void swap_two_pages_data(struct page *p1, struct page *p2,
2677 void *buf)
2678{
2679 void *kaddr1, *kaddr2;
2680
2681 kaddr1 = kmap_atomic(p1);
2682 kaddr2 = kmap_atomic(p2);
2683 copy_page(buf, kaddr1);
2684 copy_page(kaddr1, kaddr2);
2685 copy_page(kaddr2, buf);
2686 kunmap_atomic(kaddr2);
2687 kunmap_atomic(kaddr1);
2688}
2689
2690/**
2691 * restore_highmem - Put highmem image pages into their original locations.
2692 *
2693 * For each highmem page that was in use before hibernation and is included in
2694 * the image, and also has been allocated by the "restore" kernel, swap its
2695 * current contents with the previous (ie. "before hibernation") ones.
2696 *
2697 * If the restore eventually fails, we can call this function once again and
2698 * restore the highmem state as seen by the restore kernel.
2699 */
2700int restore_highmem(void)
2701{
2702 struct highmem_pbe *pbe = highmem_pblist;
2703 void *buf;
2704
2705 if (!pbe)
2706 return 0;
2707
2708 buf = get_image_page(GFP_ATOMIC, PG_SAFE);
2709 if (!buf)
2710 return -ENOMEM;
2711
2712 while (pbe) {
2713 swap_two_pages_data(pbe->copy_page, pbe->orig_page, buf);
2714 pbe = pbe->next;
2715 }
2716 free_image_page(buf, PG_UNSAFE_CLEAR);
2717 return 0;
2718}
2719#endif /* CONFIG_HIGHMEM */
1// SPDX-License-Identifier: GPL-2.0-only
2/*
3 * linux/kernel/power/snapshot.c
4 *
5 * This file provides system snapshot/restore functionality for swsusp.
6 *
7 * Copyright (C) 1998-2005 Pavel Machek <pavel@ucw.cz>
8 * Copyright (C) 2006 Rafael J. Wysocki <rjw@sisk.pl>
9 */
10
11#define pr_fmt(fmt) "PM: " 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/pgtable.h>
38#include <asm/tlbflush.h>
39#include <asm/io.h>
40
41#include "power.h"
42
43#if defined(CONFIG_STRICT_KERNEL_RWX) && defined(CONFIG_ARCH_HAS_SET_MEMORY)
44static bool hibernate_restore_protection;
45static bool hibernate_restore_protection_active;
46
47void enable_restore_image_protection(void)
48{
49 hibernate_restore_protection = true;
50}
51
52static inline void hibernate_restore_protection_begin(void)
53{
54 hibernate_restore_protection_active = hibernate_restore_protection;
55}
56
57static inline void hibernate_restore_protection_end(void)
58{
59 hibernate_restore_protection_active = false;
60}
61
62static inline void hibernate_restore_protect_page(void *page_address)
63{
64 if (hibernate_restore_protection_active)
65 set_memory_ro((unsigned long)page_address, 1);
66}
67
68static inline void hibernate_restore_unprotect_page(void *page_address)
69{
70 if (hibernate_restore_protection_active)
71 set_memory_rw((unsigned long)page_address, 1);
72}
73#else
74static inline void hibernate_restore_protection_begin(void) {}
75static inline void hibernate_restore_protection_end(void) {}
76static inline void hibernate_restore_protect_page(void *page_address) {}
77static inline void hibernate_restore_unprotect_page(void *page_address) {}
78#endif /* CONFIG_STRICT_KERNEL_RWX && CONFIG_ARCH_HAS_SET_MEMORY */
79
80static int swsusp_page_is_free(struct page *);
81static void swsusp_set_page_forbidden(struct page *);
82static void swsusp_unset_page_forbidden(struct page *);
83
84/*
85 * Number of bytes to reserve for memory allocations made by device drivers
86 * from their ->freeze() and ->freeze_noirq() callbacks so that they don't
87 * cause image creation to fail (tunable via /sys/power/reserved_size).
88 */
89unsigned long reserved_size;
90
91void __init hibernate_reserved_size_init(void)
92{
93 reserved_size = SPARE_PAGES * PAGE_SIZE;
94}
95
96/*
97 * Preferred image size in bytes (tunable via /sys/power/image_size).
98 * When it is set to N, swsusp will do its best to ensure the image
99 * size will not exceed N bytes, but if that is impossible, it will
100 * try to create the smallest image possible.
101 */
102unsigned long image_size;
103
104void __init hibernate_image_size_init(void)
105{
106 image_size = ((totalram_pages() * 2) / 5) * PAGE_SIZE;
107}
108
109/*
110 * List of PBEs needed for restoring the pages that were allocated before
111 * the suspend and included in the suspend image, but have also been
112 * allocated by the "resume" kernel, so their contents cannot be written
113 * directly to their "original" page frames.
114 */
115struct pbe *restore_pblist;
116
117/* struct linked_page is used to build chains of pages */
118
119#define LINKED_PAGE_DATA_SIZE (PAGE_SIZE - sizeof(void *))
120
121struct linked_page {
122 struct linked_page *next;
123 char data[LINKED_PAGE_DATA_SIZE];
124} __packed;
125
126/*
127 * List of "safe" pages (ie. pages that were not used by the image kernel
128 * before hibernation) that may be used as temporary storage for image kernel
129 * memory contents.
130 */
131static struct linked_page *safe_pages_list;
132
133/* Pointer to an auxiliary buffer (1 page) */
134static void *buffer;
135
136#define PG_ANY 0
137#define PG_SAFE 1
138#define PG_UNSAFE_CLEAR 1
139#define PG_UNSAFE_KEEP 0
140
141static unsigned int allocated_unsafe_pages;
142
143/**
144 * get_image_page - Allocate a page for a hibernation image.
145 * @gfp_mask: GFP mask for the allocation.
146 * @safe_needed: Get pages that were not used before hibernation (restore only)
147 *
148 * During image restoration, for storing the PBE list and the image data, we can
149 * only use memory pages that do not conflict with the pages used before
150 * hibernation. The "unsafe" pages have PageNosaveFree set and we count them
151 * using allocated_unsafe_pages.
152 *
153 * Each allocated image page is marked as PageNosave and PageNosaveFree so that
154 * swsusp_free() can release it.
155 */
156static void *get_image_page(gfp_t gfp_mask, int safe_needed)
157{
158 void *res;
159
160 res = (void *)get_zeroed_page(gfp_mask);
161 if (safe_needed)
162 while (res && swsusp_page_is_free(virt_to_page(res))) {
163 /* The page is unsafe, mark it for swsusp_free() */
164 swsusp_set_page_forbidden(virt_to_page(res));
165 allocated_unsafe_pages++;
166 res = (void *)get_zeroed_page(gfp_mask);
167 }
168 if (res) {
169 swsusp_set_page_forbidden(virt_to_page(res));
170 swsusp_set_page_free(virt_to_page(res));
171 }
172 return res;
173}
174
175static void *__get_safe_page(gfp_t gfp_mask)
176{
177 if (safe_pages_list) {
178 void *ret = safe_pages_list;
179
180 safe_pages_list = safe_pages_list->next;
181 memset(ret, 0, PAGE_SIZE);
182 return ret;
183 }
184 return get_image_page(gfp_mask, PG_SAFE);
185}
186
187unsigned long get_safe_page(gfp_t gfp_mask)
188{
189 return (unsigned long)__get_safe_page(gfp_mask);
190}
191
192static struct page *alloc_image_page(gfp_t gfp_mask)
193{
194 struct page *page;
195
196 page = alloc_page(gfp_mask);
197 if (page) {
198 swsusp_set_page_forbidden(page);
199 swsusp_set_page_free(page);
200 }
201 return page;
202}
203
204static void recycle_safe_page(void *page_address)
205{
206 struct linked_page *lp = page_address;
207
208 lp->next = safe_pages_list;
209 safe_pages_list = lp;
210}
211
212/**
213 * free_image_page - Free a page allocated for hibernation image.
214 * @addr: Address of the page to free.
215 * @clear_nosave_free: If set, clear the PageNosaveFree bit for the page.
216 *
217 * The page to free should have been allocated by get_image_page() (page flags
218 * set by it are affected).
219 */
220static inline void free_image_page(void *addr, int clear_nosave_free)
221{
222 struct page *page;
223
224 BUG_ON(!virt_addr_valid(addr));
225
226 page = virt_to_page(addr);
227
228 swsusp_unset_page_forbidden(page);
229 if (clear_nosave_free)
230 swsusp_unset_page_free(page);
231
232 __free_page(page);
233}
234
235static inline void free_list_of_pages(struct linked_page *list,
236 int clear_page_nosave)
237{
238 while (list) {
239 struct linked_page *lp = list->next;
240
241 free_image_page(list, clear_page_nosave);
242 list = lp;
243 }
244}
245
246/*
247 * struct chain_allocator is used for allocating small objects out of
248 * a linked list of pages called 'the chain'.
249 *
250 * The chain grows each time when there is no room for a new object in
251 * the current page. The allocated objects cannot be freed individually.
252 * It is only possible to free them all at once, by freeing the entire
253 * chain.
254 *
255 * NOTE: The chain allocator may be inefficient if the allocated objects
256 * are not much smaller than PAGE_SIZE.
257 */
258struct chain_allocator {
259 struct linked_page *chain; /* the chain */
260 unsigned int used_space; /* total size of objects allocated out
261 of the current page */
262 gfp_t gfp_mask; /* mask for allocating pages */
263 int safe_needed; /* if set, only "safe" pages are allocated */
264};
265
266static void chain_init(struct chain_allocator *ca, gfp_t gfp_mask,
267 int safe_needed)
268{
269 ca->chain = NULL;
270 ca->used_space = LINKED_PAGE_DATA_SIZE;
271 ca->gfp_mask = gfp_mask;
272 ca->safe_needed = safe_needed;
273}
274
275static void *chain_alloc(struct chain_allocator *ca, unsigned int size)
276{
277 void *ret;
278
279 if (LINKED_PAGE_DATA_SIZE - ca->used_space < size) {
280 struct linked_page *lp;
281
282 lp = ca->safe_needed ? __get_safe_page(ca->gfp_mask) :
283 get_image_page(ca->gfp_mask, PG_ANY);
284 if (!lp)
285 return NULL;
286
287 lp->next = ca->chain;
288 ca->chain = lp;
289 ca->used_space = 0;
290 }
291 ret = ca->chain->data + ca->used_space;
292 ca->used_space += size;
293 return ret;
294}
295
296/**
297 * Data types related to memory bitmaps.
298 *
299 * Memory bitmap is a structure consiting of many linked lists of
300 * objects. The main list's elements are of type struct zone_bitmap
301 * and each of them corresonds to one zone. For each zone bitmap
302 * object there is a list of objects of type struct bm_block that
303 * represent each blocks of bitmap in which information is stored.
304 *
305 * struct memory_bitmap contains a pointer to the main list of zone
306 * bitmap objects, a struct bm_position used for browsing the bitmap,
307 * and a pointer to the list of pages used for allocating all of the
308 * zone bitmap objects and bitmap block objects.
309 *
310 * NOTE: It has to be possible to lay out the bitmap in memory
311 * using only allocations of order 0. Additionally, the bitmap is
312 * designed to work with arbitrary number of zones (this is over the
313 * top for now, but let's avoid making unnecessary assumptions ;-).
314 *
315 * struct zone_bitmap contains a pointer to a list of bitmap block
316 * objects and a pointer to the bitmap block object that has been
317 * most recently used for setting bits. Additionally, it contains the
318 * PFNs that correspond to the start and end of the represented zone.
319 *
320 * struct bm_block contains a pointer to the memory page in which
321 * information is stored (in the form of a block of bitmap)
322 * It also contains the pfns that correspond to the start and end of
323 * the represented memory area.
324 *
325 * The memory bitmap is organized as a radix tree to guarantee fast random
326 * access to the bits. There is one radix tree for each zone (as returned
327 * from create_mem_extents).
328 *
329 * One radix tree is represented by one struct mem_zone_bm_rtree. There are
330 * two linked lists for the nodes of the tree, one for the inner nodes and
331 * one for the leave nodes. The linked leave nodes are used for fast linear
332 * access of the memory bitmap.
333 *
334 * The struct rtree_node represents one node of the radix tree.
335 */
336
337#define BM_END_OF_MAP (~0UL)
338
339#define BM_BITS_PER_BLOCK (PAGE_SIZE * BITS_PER_BYTE)
340#define BM_BLOCK_SHIFT (PAGE_SHIFT + 3)
341#define BM_BLOCK_MASK ((1UL << BM_BLOCK_SHIFT) - 1)
342
343/*
344 * struct rtree_node is a wrapper struct to link the nodes
345 * of the rtree together for easy linear iteration over
346 * bits and easy freeing
347 */
348struct rtree_node {
349 struct list_head list;
350 unsigned long *data;
351};
352
353/*
354 * struct mem_zone_bm_rtree represents a bitmap used for one
355 * populated memory zone.
356 */
357struct mem_zone_bm_rtree {
358 struct list_head list; /* Link Zones together */
359 struct list_head nodes; /* Radix Tree inner nodes */
360 struct list_head leaves; /* Radix Tree leaves */
361 unsigned long start_pfn; /* Zone start page frame */
362 unsigned long end_pfn; /* Zone end page frame + 1 */
363 struct rtree_node *rtree; /* Radix Tree Root */
364 int levels; /* Number of Radix Tree Levels */
365 unsigned int blocks; /* Number of Bitmap Blocks */
366};
367
368/* strcut bm_position is used for browsing memory bitmaps */
369
370struct bm_position {
371 struct mem_zone_bm_rtree *zone;
372 struct rtree_node *node;
373 unsigned long node_pfn;
374 int node_bit;
375};
376
377struct memory_bitmap {
378 struct list_head zones;
379 struct linked_page *p_list; /* list of pages used to store zone
380 bitmap objects and bitmap block
381 objects */
382 struct bm_position cur; /* most recently used bit position */
383};
384
385/* Functions that operate on memory bitmaps */
386
387#define BM_ENTRIES_PER_LEVEL (PAGE_SIZE / sizeof(unsigned long))
388#if BITS_PER_LONG == 32
389#define BM_RTREE_LEVEL_SHIFT (PAGE_SHIFT - 2)
390#else
391#define BM_RTREE_LEVEL_SHIFT (PAGE_SHIFT - 3)
392#endif
393#define BM_RTREE_LEVEL_MASK ((1UL << BM_RTREE_LEVEL_SHIFT) - 1)
394
395/**
396 * alloc_rtree_node - Allocate a new node and add it to the radix tree.
397 *
398 * This function is used to allocate inner nodes as well as the
399 * leave nodes of the radix tree. It also adds the node to the
400 * corresponding linked list passed in by the *list parameter.
401 */
402static struct rtree_node *alloc_rtree_node(gfp_t gfp_mask, int safe_needed,
403 struct chain_allocator *ca,
404 struct list_head *list)
405{
406 struct rtree_node *node;
407
408 node = chain_alloc(ca, sizeof(struct rtree_node));
409 if (!node)
410 return NULL;
411
412 node->data = get_image_page(gfp_mask, safe_needed);
413 if (!node->data)
414 return NULL;
415
416 list_add_tail(&node->list, list);
417
418 return node;
419}
420
421/**
422 * add_rtree_block - Add a new leave node to the radix tree.
423 *
424 * The leave nodes need to be allocated in order to keep the leaves
425 * linked list in order. This is guaranteed by the zone->blocks
426 * counter.
427 */
428static int add_rtree_block(struct mem_zone_bm_rtree *zone, gfp_t gfp_mask,
429 int safe_needed, struct chain_allocator *ca)
430{
431 struct rtree_node *node, *block, **dst;
432 unsigned int levels_needed, block_nr;
433 int i;
434
435 block_nr = zone->blocks;
436 levels_needed = 0;
437
438 /* How many levels do we need for this block nr? */
439 while (block_nr) {
440 levels_needed += 1;
441 block_nr >>= BM_RTREE_LEVEL_SHIFT;
442 }
443
444 /* Make sure the rtree has enough levels */
445 for (i = zone->levels; i < levels_needed; i++) {
446 node = alloc_rtree_node(gfp_mask, safe_needed, ca,
447 &zone->nodes);
448 if (!node)
449 return -ENOMEM;
450
451 node->data[0] = (unsigned long)zone->rtree;
452 zone->rtree = node;
453 zone->levels += 1;
454 }
455
456 /* Allocate new block */
457 block = alloc_rtree_node(gfp_mask, safe_needed, ca, &zone->leaves);
458 if (!block)
459 return -ENOMEM;
460
461 /* Now walk the rtree to insert the block */
462 node = zone->rtree;
463 dst = &zone->rtree;
464 block_nr = zone->blocks;
465 for (i = zone->levels; i > 0; i--) {
466 int index;
467
468 if (!node) {
469 node = alloc_rtree_node(gfp_mask, safe_needed, ca,
470 &zone->nodes);
471 if (!node)
472 return -ENOMEM;
473 *dst = node;
474 }
475
476 index = block_nr >> ((i - 1) * BM_RTREE_LEVEL_SHIFT);
477 index &= BM_RTREE_LEVEL_MASK;
478 dst = (struct rtree_node **)&((*dst)->data[index]);
479 node = *dst;
480 }
481
482 zone->blocks += 1;
483 *dst = block;
484
485 return 0;
486}
487
488static void free_zone_bm_rtree(struct mem_zone_bm_rtree *zone,
489 int clear_nosave_free);
490
491/**
492 * create_zone_bm_rtree - Create a radix tree for one zone.
493 *
494 * Allocated the mem_zone_bm_rtree structure and initializes it.
495 * This function also allocated and builds the radix tree for the
496 * zone.
497 */
498static struct mem_zone_bm_rtree *create_zone_bm_rtree(gfp_t gfp_mask,
499 int safe_needed,
500 struct chain_allocator *ca,
501 unsigned long start,
502 unsigned long end)
503{
504 struct mem_zone_bm_rtree *zone;
505 unsigned int i, nr_blocks;
506 unsigned long pages;
507
508 pages = end - start;
509 zone = chain_alloc(ca, sizeof(struct mem_zone_bm_rtree));
510 if (!zone)
511 return NULL;
512
513 INIT_LIST_HEAD(&zone->nodes);
514 INIT_LIST_HEAD(&zone->leaves);
515 zone->start_pfn = start;
516 zone->end_pfn = end;
517 nr_blocks = DIV_ROUND_UP(pages, BM_BITS_PER_BLOCK);
518
519 for (i = 0; i < nr_blocks; i++) {
520 if (add_rtree_block(zone, gfp_mask, safe_needed, ca)) {
521 free_zone_bm_rtree(zone, PG_UNSAFE_CLEAR);
522 return NULL;
523 }
524 }
525
526 return zone;
527}
528
529/**
530 * free_zone_bm_rtree - Free the memory of the radix tree.
531 *
532 * Free all node pages of the radix tree. The mem_zone_bm_rtree
533 * structure itself is not freed here nor are the rtree_node
534 * structs.
535 */
536static void free_zone_bm_rtree(struct mem_zone_bm_rtree *zone,
537 int clear_nosave_free)
538{
539 struct rtree_node *node;
540
541 list_for_each_entry(node, &zone->nodes, list)
542 free_image_page(node->data, clear_nosave_free);
543
544 list_for_each_entry(node, &zone->leaves, list)
545 free_image_page(node->data, clear_nosave_free);
546}
547
548static void memory_bm_position_reset(struct memory_bitmap *bm)
549{
550 bm->cur.zone = list_entry(bm->zones.next, struct mem_zone_bm_rtree,
551 list);
552 bm->cur.node = list_entry(bm->cur.zone->leaves.next,
553 struct rtree_node, list);
554 bm->cur.node_pfn = 0;
555 bm->cur.node_bit = 0;
556}
557
558static void memory_bm_free(struct memory_bitmap *bm, int clear_nosave_free);
559
560struct mem_extent {
561 struct list_head hook;
562 unsigned long start;
563 unsigned long end;
564};
565
566/**
567 * free_mem_extents - Free a list of memory extents.
568 * @list: List of extents to free.
569 */
570static void free_mem_extents(struct list_head *list)
571{
572 struct mem_extent *ext, *aux;
573
574 list_for_each_entry_safe(ext, aux, list, hook) {
575 list_del(&ext->hook);
576 kfree(ext);
577 }
578}
579
580/**
581 * create_mem_extents - Create a list of memory extents.
582 * @list: List to put the extents into.
583 * @gfp_mask: Mask to use for memory allocations.
584 *
585 * The extents represent contiguous ranges of PFNs.
586 */
587static int create_mem_extents(struct list_head *list, gfp_t gfp_mask)
588{
589 struct zone *zone;
590
591 INIT_LIST_HEAD(list);
592
593 for_each_populated_zone(zone) {
594 unsigned long zone_start, zone_end;
595 struct mem_extent *ext, *cur, *aux;
596
597 zone_start = zone->zone_start_pfn;
598 zone_end = zone_end_pfn(zone);
599
600 list_for_each_entry(ext, list, hook)
601 if (zone_start <= ext->end)
602 break;
603
604 if (&ext->hook == list || zone_end < ext->start) {
605 /* New extent is necessary */
606 struct mem_extent *new_ext;
607
608 new_ext = kzalloc(sizeof(struct mem_extent), gfp_mask);
609 if (!new_ext) {
610 free_mem_extents(list);
611 return -ENOMEM;
612 }
613 new_ext->start = zone_start;
614 new_ext->end = zone_end;
615 list_add_tail(&new_ext->hook, &ext->hook);
616 continue;
617 }
618
619 /* Merge this zone's range of PFNs with the existing one */
620 if (zone_start < ext->start)
621 ext->start = zone_start;
622 if (zone_end > ext->end)
623 ext->end = zone_end;
624
625 /* More merging may be possible */
626 cur = ext;
627 list_for_each_entry_safe_continue(cur, aux, list, hook) {
628 if (zone_end < cur->start)
629 break;
630 if (zone_end < cur->end)
631 ext->end = cur->end;
632 list_del(&cur->hook);
633 kfree(cur);
634 }
635 }
636
637 return 0;
638}
639
640/**
641 * memory_bm_create - Allocate memory for a memory bitmap.
642 */
643static int memory_bm_create(struct memory_bitmap *bm, gfp_t gfp_mask,
644 int safe_needed)
645{
646 struct chain_allocator ca;
647 struct list_head mem_extents;
648 struct mem_extent *ext;
649 int error;
650
651 chain_init(&ca, gfp_mask, safe_needed);
652 INIT_LIST_HEAD(&bm->zones);
653
654 error = create_mem_extents(&mem_extents, gfp_mask);
655 if (error)
656 return error;
657
658 list_for_each_entry(ext, &mem_extents, hook) {
659 struct mem_zone_bm_rtree *zone;
660
661 zone = create_zone_bm_rtree(gfp_mask, safe_needed, &ca,
662 ext->start, ext->end);
663 if (!zone) {
664 error = -ENOMEM;
665 goto Error;
666 }
667 list_add_tail(&zone->list, &bm->zones);
668 }
669
670 bm->p_list = ca.chain;
671 memory_bm_position_reset(bm);
672 Exit:
673 free_mem_extents(&mem_extents);
674 return error;
675
676 Error:
677 bm->p_list = ca.chain;
678 memory_bm_free(bm, PG_UNSAFE_CLEAR);
679 goto Exit;
680}
681
682/**
683 * memory_bm_free - Free memory occupied by the memory bitmap.
684 * @bm: Memory bitmap.
685 */
686static void memory_bm_free(struct memory_bitmap *bm, int clear_nosave_free)
687{
688 struct mem_zone_bm_rtree *zone;
689
690 list_for_each_entry(zone, &bm->zones, list)
691 free_zone_bm_rtree(zone, clear_nosave_free);
692
693 free_list_of_pages(bm->p_list, clear_nosave_free);
694
695 INIT_LIST_HEAD(&bm->zones);
696}
697
698/**
699 * memory_bm_find_bit - Find the bit for a given PFN in a memory bitmap.
700 *
701 * Find the bit in memory bitmap @bm that corresponds to the given PFN.
702 * The cur.zone, cur.block and cur.node_pfn members of @bm are updated.
703 *
704 * Walk the radix tree to find the page containing the bit that represents @pfn
705 * and return the position of the bit in @addr and @bit_nr.
706 */
707static int memory_bm_find_bit(struct memory_bitmap *bm, unsigned long pfn,
708 void **addr, unsigned int *bit_nr)
709{
710 struct mem_zone_bm_rtree *curr, *zone;
711 struct rtree_node *node;
712 int i, block_nr;
713
714 zone = bm->cur.zone;
715
716 if (pfn >= zone->start_pfn && pfn < zone->end_pfn)
717 goto zone_found;
718
719 zone = NULL;
720
721 /* Find the right zone */
722 list_for_each_entry(curr, &bm->zones, list) {
723 if (pfn >= curr->start_pfn && pfn < curr->end_pfn) {
724 zone = curr;
725 break;
726 }
727 }
728
729 if (!zone)
730 return -EFAULT;
731
732zone_found:
733 /*
734 * We have found the zone. Now walk the radix tree to find the leaf node
735 * for our PFN.
736 */
737 node = bm->cur.node;
738 if (((pfn - zone->start_pfn) & ~BM_BLOCK_MASK) == bm->cur.node_pfn)
739 goto node_found;
740
741 node = zone->rtree;
742 block_nr = (pfn - zone->start_pfn) >> BM_BLOCK_SHIFT;
743
744 for (i = zone->levels; i > 0; i--) {
745 int index;
746
747 index = block_nr >> ((i - 1) * BM_RTREE_LEVEL_SHIFT);
748 index &= BM_RTREE_LEVEL_MASK;
749 BUG_ON(node->data[index] == 0);
750 node = (struct rtree_node *)node->data[index];
751 }
752
753node_found:
754 /* Update last position */
755 bm->cur.zone = zone;
756 bm->cur.node = node;
757 bm->cur.node_pfn = (pfn - zone->start_pfn) & ~BM_BLOCK_MASK;
758
759 /* Set return values */
760 *addr = node->data;
761 *bit_nr = (pfn - zone->start_pfn) & BM_BLOCK_MASK;
762
763 return 0;
764}
765
766static void memory_bm_set_bit(struct memory_bitmap *bm, unsigned long pfn)
767{
768 void *addr;
769 unsigned int bit;
770 int error;
771
772 error = memory_bm_find_bit(bm, pfn, &addr, &bit);
773 BUG_ON(error);
774 set_bit(bit, addr);
775}
776
777static int mem_bm_set_bit_check(struct memory_bitmap *bm, unsigned long pfn)
778{
779 void *addr;
780 unsigned int bit;
781 int error;
782
783 error = memory_bm_find_bit(bm, pfn, &addr, &bit);
784 if (!error)
785 set_bit(bit, addr);
786
787 return error;
788}
789
790static void memory_bm_clear_bit(struct memory_bitmap *bm, unsigned long pfn)
791{
792 void *addr;
793 unsigned int bit;
794 int error;
795
796 error = memory_bm_find_bit(bm, pfn, &addr, &bit);
797 BUG_ON(error);
798 clear_bit(bit, addr);
799}
800
801static void memory_bm_clear_current(struct memory_bitmap *bm)
802{
803 int bit;
804
805 bit = max(bm->cur.node_bit - 1, 0);
806 clear_bit(bit, bm->cur.node->data);
807}
808
809static int memory_bm_test_bit(struct memory_bitmap *bm, unsigned long pfn)
810{
811 void *addr;
812 unsigned int bit;
813 int error;
814
815 error = memory_bm_find_bit(bm, pfn, &addr, &bit);
816 BUG_ON(error);
817 return test_bit(bit, addr);
818}
819
820static bool memory_bm_pfn_present(struct memory_bitmap *bm, unsigned long pfn)
821{
822 void *addr;
823 unsigned int bit;
824
825 return !memory_bm_find_bit(bm, pfn, &addr, &bit);
826}
827
828/*
829 * rtree_next_node - Jump to the next leaf node.
830 *
831 * Set the position to the beginning of the next node in the
832 * memory bitmap. This is either the next node in the current
833 * zone's radix tree or the first node in the radix tree of the
834 * next zone.
835 *
836 * Return true if there is a next node, false otherwise.
837 */
838static bool rtree_next_node(struct memory_bitmap *bm)
839{
840 if (!list_is_last(&bm->cur.node->list, &bm->cur.zone->leaves)) {
841 bm->cur.node = list_entry(bm->cur.node->list.next,
842 struct rtree_node, list);
843 bm->cur.node_pfn += BM_BITS_PER_BLOCK;
844 bm->cur.node_bit = 0;
845 touch_softlockup_watchdog();
846 return true;
847 }
848
849 /* No more nodes, goto next zone */
850 if (!list_is_last(&bm->cur.zone->list, &bm->zones)) {
851 bm->cur.zone = list_entry(bm->cur.zone->list.next,
852 struct mem_zone_bm_rtree, list);
853 bm->cur.node = list_entry(bm->cur.zone->leaves.next,
854 struct rtree_node, list);
855 bm->cur.node_pfn = 0;
856 bm->cur.node_bit = 0;
857 return true;
858 }
859
860 /* No more zones */
861 return false;
862}
863
864/**
865 * memory_bm_rtree_next_pfn - Find the next set bit in a memory bitmap.
866 * @bm: Memory bitmap.
867 *
868 * Starting from the last returned position this function searches for the next
869 * set bit in @bm and returns the PFN represented by it. If no more bits are
870 * set, BM_END_OF_MAP is returned.
871 *
872 * It is required to run memory_bm_position_reset() before the first call to
873 * this function for the given memory bitmap.
874 */
875static unsigned long memory_bm_next_pfn(struct memory_bitmap *bm)
876{
877 unsigned long bits, pfn, pages;
878 int bit;
879
880 do {
881 pages = bm->cur.zone->end_pfn - bm->cur.zone->start_pfn;
882 bits = min(pages - bm->cur.node_pfn, BM_BITS_PER_BLOCK);
883 bit = find_next_bit(bm->cur.node->data, bits,
884 bm->cur.node_bit);
885 if (bit < bits) {
886 pfn = bm->cur.zone->start_pfn + bm->cur.node_pfn + bit;
887 bm->cur.node_bit = bit + 1;
888 return pfn;
889 }
890 } while (rtree_next_node(bm));
891
892 return BM_END_OF_MAP;
893}
894
895/*
896 * This structure represents a range of page frames the contents of which
897 * should not be saved during hibernation.
898 */
899struct nosave_region {
900 struct list_head list;
901 unsigned long start_pfn;
902 unsigned long end_pfn;
903};
904
905static LIST_HEAD(nosave_regions);
906
907static void recycle_zone_bm_rtree(struct mem_zone_bm_rtree *zone)
908{
909 struct rtree_node *node;
910
911 list_for_each_entry(node, &zone->nodes, list)
912 recycle_safe_page(node->data);
913
914 list_for_each_entry(node, &zone->leaves, list)
915 recycle_safe_page(node->data);
916}
917
918static void memory_bm_recycle(struct memory_bitmap *bm)
919{
920 struct mem_zone_bm_rtree *zone;
921 struct linked_page *p_list;
922
923 list_for_each_entry(zone, &bm->zones, list)
924 recycle_zone_bm_rtree(zone);
925
926 p_list = bm->p_list;
927 while (p_list) {
928 struct linked_page *lp = p_list;
929
930 p_list = lp->next;
931 recycle_safe_page(lp);
932 }
933}
934
935/**
936 * register_nosave_region - Register a region of unsaveable memory.
937 *
938 * Register a range of page frames the contents of which should not be saved
939 * during hibernation (to be used in the early initialization code).
940 */
941void __init __register_nosave_region(unsigned long start_pfn,
942 unsigned long end_pfn, int use_kmalloc)
943{
944 struct nosave_region *region;
945
946 if (start_pfn >= end_pfn)
947 return;
948
949 if (!list_empty(&nosave_regions)) {
950 /* Try to extend the previous region (they should be sorted) */
951 region = list_entry(nosave_regions.prev,
952 struct nosave_region, list);
953 if (region->end_pfn == start_pfn) {
954 region->end_pfn = end_pfn;
955 goto Report;
956 }
957 }
958 if (use_kmalloc) {
959 /* During init, this shouldn't fail */
960 region = kmalloc(sizeof(struct nosave_region), GFP_KERNEL);
961 BUG_ON(!region);
962 } else {
963 /* This allocation cannot fail */
964 region = memblock_alloc(sizeof(struct nosave_region),
965 SMP_CACHE_BYTES);
966 if (!region)
967 panic("%s: Failed to allocate %zu bytes\n", __func__,
968 sizeof(struct nosave_region));
969 }
970 region->start_pfn = start_pfn;
971 region->end_pfn = end_pfn;
972 list_add_tail(®ion->list, &nosave_regions);
973 Report:
974 pr_info("Registered nosave memory: [mem %#010llx-%#010llx]\n",
975 (unsigned long long) start_pfn << PAGE_SHIFT,
976 ((unsigned long long) end_pfn << PAGE_SHIFT) - 1);
977}
978
979/*
980 * Set bits in this map correspond to the page frames the contents of which
981 * should not be saved during the suspend.
982 */
983static struct memory_bitmap *forbidden_pages_map;
984
985/* Set bits in this map correspond to free page frames. */
986static struct memory_bitmap *free_pages_map;
987
988/*
989 * Each page frame allocated for creating the image is marked by setting the
990 * corresponding bits in forbidden_pages_map and free_pages_map simultaneously
991 */
992
993void swsusp_set_page_free(struct page *page)
994{
995 if (free_pages_map)
996 memory_bm_set_bit(free_pages_map, page_to_pfn(page));
997}
998
999static int swsusp_page_is_free(struct page *page)
1000{
1001 return free_pages_map ?
1002 memory_bm_test_bit(free_pages_map, page_to_pfn(page)) : 0;
1003}
1004
1005void swsusp_unset_page_free(struct page *page)
1006{
1007 if (free_pages_map)
1008 memory_bm_clear_bit(free_pages_map, page_to_pfn(page));
1009}
1010
1011static void swsusp_set_page_forbidden(struct page *page)
1012{
1013 if (forbidden_pages_map)
1014 memory_bm_set_bit(forbidden_pages_map, page_to_pfn(page));
1015}
1016
1017int swsusp_page_is_forbidden(struct page *page)
1018{
1019 return forbidden_pages_map ?
1020 memory_bm_test_bit(forbidden_pages_map, page_to_pfn(page)) : 0;
1021}
1022
1023static void swsusp_unset_page_forbidden(struct page *page)
1024{
1025 if (forbidden_pages_map)
1026 memory_bm_clear_bit(forbidden_pages_map, page_to_pfn(page));
1027}
1028
1029/**
1030 * mark_nosave_pages - Mark pages that should not be saved.
1031 * @bm: Memory bitmap.
1032 *
1033 * Set the bits in @bm that correspond to the page frames the contents of which
1034 * should not be saved.
1035 */
1036static void mark_nosave_pages(struct memory_bitmap *bm)
1037{
1038 struct nosave_region *region;
1039
1040 if (list_empty(&nosave_regions))
1041 return;
1042
1043 list_for_each_entry(region, &nosave_regions, list) {
1044 unsigned long pfn;
1045
1046 pr_debug("Marking nosave pages: [mem %#010llx-%#010llx]\n",
1047 (unsigned long long) region->start_pfn << PAGE_SHIFT,
1048 ((unsigned long long) region->end_pfn << PAGE_SHIFT)
1049 - 1);
1050
1051 for (pfn = region->start_pfn; pfn < region->end_pfn; pfn++)
1052 if (pfn_valid(pfn)) {
1053 /*
1054 * It is safe to ignore the result of
1055 * mem_bm_set_bit_check() here, since we won't
1056 * touch the PFNs for which the error is
1057 * returned anyway.
1058 */
1059 mem_bm_set_bit_check(bm, pfn);
1060 }
1061 }
1062}
1063
1064/**
1065 * create_basic_memory_bitmaps - Create bitmaps to hold basic page information.
1066 *
1067 * Create bitmaps needed for marking page frames that should not be saved and
1068 * free page frames. The forbidden_pages_map and free_pages_map pointers are
1069 * only modified if everything goes well, because we don't want the bits to be
1070 * touched before both bitmaps are set up.
1071 */
1072int create_basic_memory_bitmaps(void)
1073{
1074 struct memory_bitmap *bm1, *bm2;
1075 int error = 0;
1076
1077 if (forbidden_pages_map && free_pages_map)
1078 return 0;
1079 else
1080 BUG_ON(forbidden_pages_map || free_pages_map);
1081
1082 bm1 = kzalloc(sizeof(struct memory_bitmap), GFP_KERNEL);
1083 if (!bm1)
1084 return -ENOMEM;
1085
1086 error = memory_bm_create(bm1, GFP_KERNEL, PG_ANY);
1087 if (error)
1088 goto Free_first_object;
1089
1090 bm2 = kzalloc(sizeof(struct memory_bitmap), GFP_KERNEL);
1091 if (!bm2)
1092 goto Free_first_bitmap;
1093
1094 error = memory_bm_create(bm2, GFP_KERNEL, PG_ANY);
1095 if (error)
1096 goto Free_second_object;
1097
1098 forbidden_pages_map = bm1;
1099 free_pages_map = bm2;
1100 mark_nosave_pages(forbidden_pages_map);
1101
1102 pr_debug("Basic memory bitmaps created\n");
1103
1104 return 0;
1105
1106 Free_second_object:
1107 kfree(bm2);
1108 Free_first_bitmap:
1109 memory_bm_free(bm1, PG_UNSAFE_CLEAR);
1110 Free_first_object:
1111 kfree(bm1);
1112 return -ENOMEM;
1113}
1114
1115/**
1116 * free_basic_memory_bitmaps - Free memory bitmaps holding basic information.
1117 *
1118 * Free memory bitmaps allocated by create_basic_memory_bitmaps(). The
1119 * auxiliary pointers are necessary so that the bitmaps themselves are not
1120 * referred to while they are being freed.
1121 */
1122void free_basic_memory_bitmaps(void)
1123{
1124 struct memory_bitmap *bm1, *bm2;
1125
1126 if (WARN_ON(!(forbidden_pages_map && free_pages_map)))
1127 return;
1128
1129 bm1 = forbidden_pages_map;
1130 bm2 = free_pages_map;
1131 forbidden_pages_map = NULL;
1132 free_pages_map = NULL;
1133 memory_bm_free(bm1, PG_UNSAFE_CLEAR);
1134 kfree(bm1);
1135 memory_bm_free(bm2, PG_UNSAFE_CLEAR);
1136 kfree(bm2);
1137
1138 pr_debug("Basic memory bitmaps freed\n");
1139}
1140
1141void clear_free_pages(void)
1142{
1143#ifdef CONFIG_PAGE_POISONING_ZERO
1144 struct memory_bitmap *bm = free_pages_map;
1145 unsigned long pfn;
1146
1147 if (WARN_ON(!(free_pages_map)))
1148 return;
1149
1150 memory_bm_position_reset(bm);
1151 pfn = memory_bm_next_pfn(bm);
1152 while (pfn != BM_END_OF_MAP) {
1153 if (pfn_valid(pfn))
1154 clear_highpage(pfn_to_page(pfn));
1155
1156 pfn = memory_bm_next_pfn(bm);
1157 }
1158 memory_bm_position_reset(bm);
1159 pr_info("free pages cleared after restore\n");
1160#endif /* PAGE_POISONING_ZERO */
1161}
1162
1163/**
1164 * snapshot_additional_pages - Estimate the number of extra pages needed.
1165 * @zone: Memory zone to carry out the computation for.
1166 *
1167 * Estimate the number of additional pages needed for setting up a hibernation
1168 * image data structures for @zone (usually, the returned value is greater than
1169 * the exact number).
1170 */
1171unsigned int snapshot_additional_pages(struct zone *zone)
1172{
1173 unsigned int rtree, nodes;
1174
1175 rtree = nodes = DIV_ROUND_UP(zone->spanned_pages, BM_BITS_PER_BLOCK);
1176 rtree += DIV_ROUND_UP(rtree * sizeof(struct rtree_node),
1177 LINKED_PAGE_DATA_SIZE);
1178 while (nodes > 1) {
1179 nodes = DIV_ROUND_UP(nodes, BM_ENTRIES_PER_LEVEL);
1180 rtree += nodes;
1181 }
1182
1183 return 2 * rtree;
1184}
1185
1186#ifdef CONFIG_HIGHMEM
1187/**
1188 * count_free_highmem_pages - Compute the total number of free highmem pages.
1189 *
1190 * The returned number is system-wide.
1191 */
1192static unsigned int count_free_highmem_pages(void)
1193{
1194 struct zone *zone;
1195 unsigned int cnt = 0;
1196
1197 for_each_populated_zone(zone)
1198 if (is_highmem(zone))
1199 cnt += zone_page_state(zone, NR_FREE_PAGES);
1200
1201 return cnt;
1202}
1203
1204/**
1205 * saveable_highmem_page - Check if a highmem page is saveable.
1206 *
1207 * Determine whether a highmem page should be included in a hibernation image.
1208 *
1209 * We should save the page if it isn't Nosave or NosaveFree, or Reserved,
1210 * and it isn't part of a free chunk of pages.
1211 */
1212static struct page *saveable_highmem_page(struct zone *zone, unsigned long pfn)
1213{
1214 struct page *page;
1215
1216 if (!pfn_valid(pfn))
1217 return NULL;
1218
1219 page = pfn_to_online_page(pfn);
1220 if (!page || page_zone(page) != zone)
1221 return NULL;
1222
1223 BUG_ON(!PageHighMem(page));
1224
1225 if (swsusp_page_is_forbidden(page) || swsusp_page_is_free(page))
1226 return NULL;
1227
1228 if (PageReserved(page) || PageOffline(page))
1229 return NULL;
1230
1231 if (page_is_guard(page))
1232 return NULL;
1233
1234 return page;
1235}
1236
1237/**
1238 * count_highmem_pages - Compute the total number of saveable highmem pages.
1239 */
1240static unsigned int count_highmem_pages(void)
1241{
1242 struct zone *zone;
1243 unsigned int n = 0;
1244
1245 for_each_populated_zone(zone) {
1246 unsigned long pfn, max_zone_pfn;
1247
1248 if (!is_highmem(zone))
1249 continue;
1250
1251 mark_free_pages(zone);
1252 max_zone_pfn = zone_end_pfn(zone);
1253 for (pfn = zone->zone_start_pfn; pfn < max_zone_pfn; pfn++)
1254 if (saveable_highmem_page(zone, pfn))
1255 n++;
1256 }
1257 return n;
1258}
1259#else
1260static inline void *saveable_highmem_page(struct zone *z, unsigned long p)
1261{
1262 return NULL;
1263}
1264#endif /* CONFIG_HIGHMEM */
1265
1266/**
1267 * saveable_page - Check if the given page is saveable.
1268 *
1269 * Determine whether a non-highmem page should be included in a hibernation
1270 * image.
1271 *
1272 * We should save the page if it isn't Nosave, and is not in the range
1273 * of pages statically defined as 'unsaveable', and it isn't part of
1274 * a free chunk of pages.
1275 */
1276static struct page *saveable_page(struct zone *zone, unsigned long pfn)
1277{
1278 struct page *page;
1279
1280 if (!pfn_valid(pfn))
1281 return NULL;
1282
1283 page = pfn_to_online_page(pfn);
1284 if (!page || page_zone(page) != zone)
1285 return NULL;
1286
1287 BUG_ON(PageHighMem(page));
1288
1289 if (swsusp_page_is_forbidden(page) || swsusp_page_is_free(page))
1290 return NULL;
1291
1292 if (PageOffline(page))
1293 return NULL;
1294
1295 if (PageReserved(page)
1296 && (!kernel_page_present(page) || pfn_is_nosave(pfn)))
1297 return NULL;
1298
1299 if (page_is_guard(page))
1300 return NULL;
1301
1302 return page;
1303}
1304
1305/**
1306 * count_data_pages - Compute the total number of saveable non-highmem pages.
1307 */
1308static unsigned int count_data_pages(void)
1309{
1310 struct zone *zone;
1311 unsigned long pfn, max_zone_pfn;
1312 unsigned int n = 0;
1313
1314 for_each_populated_zone(zone) {
1315 if (is_highmem(zone))
1316 continue;
1317
1318 mark_free_pages(zone);
1319 max_zone_pfn = zone_end_pfn(zone);
1320 for (pfn = zone->zone_start_pfn; pfn < max_zone_pfn; pfn++)
1321 if (saveable_page(zone, pfn))
1322 n++;
1323 }
1324 return n;
1325}
1326
1327/*
1328 * This is needed, because copy_page and memcpy are not usable for copying
1329 * task structs.
1330 */
1331static inline void do_copy_page(long *dst, long *src)
1332{
1333 int n;
1334
1335 for (n = PAGE_SIZE / sizeof(long); n; n--)
1336 *dst++ = *src++;
1337}
1338
1339/**
1340 * safe_copy_page - Copy a page in a safe way.
1341 *
1342 * Check if the page we are going to copy is marked as present in the kernel
1343 * page tables. This always is the case if CONFIG_DEBUG_PAGEALLOC or
1344 * CONFIG_ARCH_HAS_SET_DIRECT_MAP is not set. In that case kernel_page_present()
1345 * always returns 'true'.
1346 */
1347static void safe_copy_page(void *dst, struct page *s_page)
1348{
1349 if (kernel_page_present(s_page)) {
1350 do_copy_page(dst, page_address(s_page));
1351 } else {
1352 kernel_map_pages(s_page, 1, 1);
1353 do_copy_page(dst, page_address(s_page));
1354 kernel_map_pages(s_page, 1, 0);
1355 }
1356}
1357
1358#ifdef CONFIG_HIGHMEM
1359static inline struct page *page_is_saveable(struct zone *zone, unsigned long pfn)
1360{
1361 return is_highmem(zone) ?
1362 saveable_highmem_page(zone, pfn) : saveable_page(zone, pfn);
1363}
1364
1365static void copy_data_page(unsigned long dst_pfn, unsigned long src_pfn)
1366{
1367 struct page *s_page, *d_page;
1368 void *src, *dst;
1369
1370 s_page = pfn_to_page(src_pfn);
1371 d_page = pfn_to_page(dst_pfn);
1372 if (PageHighMem(s_page)) {
1373 src = kmap_atomic(s_page);
1374 dst = kmap_atomic(d_page);
1375 do_copy_page(dst, src);
1376 kunmap_atomic(dst);
1377 kunmap_atomic(src);
1378 } else {
1379 if (PageHighMem(d_page)) {
1380 /*
1381 * The page pointed to by src may contain some kernel
1382 * data modified by kmap_atomic()
1383 */
1384 safe_copy_page(buffer, s_page);
1385 dst = kmap_atomic(d_page);
1386 copy_page(dst, buffer);
1387 kunmap_atomic(dst);
1388 } else {
1389 safe_copy_page(page_address(d_page), s_page);
1390 }
1391 }
1392}
1393#else
1394#define page_is_saveable(zone, pfn) saveable_page(zone, pfn)
1395
1396static inline void copy_data_page(unsigned long dst_pfn, unsigned long src_pfn)
1397{
1398 safe_copy_page(page_address(pfn_to_page(dst_pfn)),
1399 pfn_to_page(src_pfn));
1400}
1401#endif /* CONFIG_HIGHMEM */
1402
1403static void copy_data_pages(struct memory_bitmap *copy_bm,
1404 struct memory_bitmap *orig_bm)
1405{
1406 struct zone *zone;
1407 unsigned long pfn;
1408
1409 for_each_populated_zone(zone) {
1410 unsigned long max_zone_pfn;
1411
1412 mark_free_pages(zone);
1413 max_zone_pfn = zone_end_pfn(zone);
1414 for (pfn = zone->zone_start_pfn; pfn < max_zone_pfn; pfn++)
1415 if (page_is_saveable(zone, pfn))
1416 memory_bm_set_bit(orig_bm, pfn);
1417 }
1418 memory_bm_position_reset(orig_bm);
1419 memory_bm_position_reset(copy_bm);
1420 for(;;) {
1421 pfn = memory_bm_next_pfn(orig_bm);
1422 if (unlikely(pfn == BM_END_OF_MAP))
1423 break;
1424 copy_data_page(memory_bm_next_pfn(copy_bm), pfn);
1425 }
1426}
1427
1428/* Total number of image pages */
1429static unsigned int nr_copy_pages;
1430/* Number of pages needed for saving the original pfns of the image pages */
1431static unsigned int nr_meta_pages;
1432/*
1433 * Numbers of normal and highmem page frames allocated for hibernation image
1434 * before suspending devices.
1435 */
1436static unsigned int alloc_normal, alloc_highmem;
1437/*
1438 * Memory bitmap used for marking saveable pages (during hibernation) or
1439 * hibernation image pages (during restore)
1440 */
1441static struct memory_bitmap orig_bm;
1442/*
1443 * Memory bitmap used during hibernation for marking allocated page frames that
1444 * will contain copies of saveable pages. During restore it is initially used
1445 * for marking hibernation image pages, but then the set bits from it are
1446 * duplicated in @orig_bm and it is released. On highmem systems it is next
1447 * used for marking "safe" highmem pages, but it has to be reinitialized for
1448 * this purpose.
1449 */
1450static struct memory_bitmap copy_bm;
1451
1452/**
1453 * swsusp_free - Free pages allocated for hibernation image.
1454 *
1455 * Image pages are alocated before snapshot creation, so they need to be
1456 * released after resume.
1457 */
1458void swsusp_free(void)
1459{
1460 unsigned long fb_pfn, fr_pfn;
1461
1462 if (!forbidden_pages_map || !free_pages_map)
1463 goto out;
1464
1465 memory_bm_position_reset(forbidden_pages_map);
1466 memory_bm_position_reset(free_pages_map);
1467
1468loop:
1469 fr_pfn = memory_bm_next_pfn(free_pages_map);
1470 fb_pfn = memory_bm_next_pfn(forbidden_pages_map);
1471
1472 /*
1473 * Find the next bit set in both bitmaps. This is guaranteed to
1474 * terminate when fb_pfn == fr_pfn == BM_END_OF_MAP.
1475 */
1476 do {
1477 if (fb_pfn < fr_pfn)
1478 fb_pfn = memory_bm_next_pfn(forbidden_pages_map);
1479 if (fr_pfn < fb_pfn)
1480 fr_pfn = memory_bm_next_pfn(free_pages_map);
1481 } while (fb_pfn != fr_pfn);
1482
1483 if (fr_pfn != BM_END_OF_MAP && pfn_valid(fr_pfn)) {
1484 struct page *page = pfn_to_page(fr_pfn);
1485
1486 memory_bm_clear_current(forbidden_pages_map);
1487 memory_bm_clear_current(free_pages_map);
1488 hibernate_restore_unprotect_page(page_address(page));
1489 __free_page(page);
1490 goto loop;
1491 }
1492
1493out:
1494 nr_copy_pages = 0;
1495 nr_meta_pages = 0;
1496 restore_pblist = NULL;
1497 buffer = NULL;
1498 alloc_normal = 0;
1499 alloc_highmem = 0;
1500 hibernate_restore_protection_end();
1501}
1502
1503/* Helper functions used for the shrinking of memory. */
1504
1505#define GFP_IMAGE (GFP_KERNEL | __GFP_NOWARN)
1506
1507/**
1508 * preallocate_image_pages - Allocate a number of pages for hibernation image.
1509 * @nr_pages: Number of page frames to allocate.
1510 * @mask: GFP flags to use for the allocation.
1511 *
1512 * Return value: Number of page frames actually allocated
1513 */
1514static unsigned long preallocate_image_pages(unsigned long nr_pages, gfp_t mask)
1515{
1516 unsigned long nr_alloc = 0;
1517
1518 while (nr_pages > 0) {
1519 struct page *page;
1520
1521 page = alloc_image_page(mask);
1522 if (!page)
1523 break;
1524 memory_bm_set_bit(©_bm, page_to_pfn(page));
1525 if (PageHighMem(page))
1526 alloc_highmem++;
1527 else
1528 alloc_normal++;
1529 nr_pages--;
1530 nr_alloc++;
1531 }
1532
1533 return nr_alloc;
1534}
1535
1536static unsigned long preallocate_image_memory(unsigned long nr_pages,
1537 unsigned long avail_normal)
1538{
1539 unsigned long alloc;
1540
1541 if (avail_normal <= alloc_normal)
1542 return 0;
1543
1544 alloc = avail_normal - alloc_normal;
1545 if (nr_pages < alloc)
1546 alloc = nr_pages;
1547
1548 return preallocate_image_pages(alloc, GFP_IMAGE);
1549}
1550
1551#ifdef CONFIG_HIGHMEM
1552static unsigned long preallocate_image_highmem(unsigned long nr_pages)
1553{
1554 return preallocate_image_pages(nr_pages, GFP_IMAGE | __GFP_HIGHMEM);
1555}
1556
1557/**
1558 * __fraction - Compute (an approximation of) x * (multiplier / base).
1559 */
1560static unsigned long __fraction(u64 x, u64 multiplier, u64 base)
1561{
1562 x *= multiplier;
1563 do_div(x, base);
1564 return (unsigned long)x;
1565}
1566
1567static unsigned long preallocate_highmem_fraction(unsigned long nr_pages,
1568 unsigned long highmem,
1569 unsigned long total)
1570{
1571 unsigned long alloc = __fraction(nr_pages, highmem, total);
1572
1573 return preallocate_image_pages(alloc, GFP_IMAGE | __GFP_HIGHMEM);
1574}
1575#else /* CONFIG_HIGHMEM */
1576static inline unsigned long preallocate_image_highmem(unsigned long nr_pages)
1577{
1578 return 0;
1579}
1580
1581static inline unsigned long preallocate_highmem_fraction(unsigned long nr_pages,
1582 unsigned long highmem,
1583 unsigned long total)
1584{
1585 return 0;
1586}
1587#endif /* CONFIG_HIGHMEM */
1588
1589/**
1590 * free_unnecessary_pages - Release preallocated pages not needed for the image.
1591 */
1592static unsigned long free_unnecessary_pages(void)
1593{
1594 unsigned long save, to_free_normal, to_free_highmem, free;
1595
1596 save = count_data_pages();
1597 if (alloc_normal >= save) {
1598 to_free_normal = alloc_normal - save;
1599 save = 0;
1600 } else {
1601 to_free_normal = 0;
1602 save -= alloc_normal;
1603 }
1604 save += count_highmem_pages();
1605 if (alloc_highmem >= save) {
1606 to_free_highmem = alloc_highmem - save;
1607 } else {
1608 to_free_highmem = 0;
1609 save -= alloc_highmem;
1610 if (to_free_normal > save)
1611 to_free_normal -= save;
1612 else
1613 to_free_normal = 0;
1614 }
1615 free = to_free_normal + to_free_highmem;
1616
1617 memory_bm_position_reset(©_bm);
1618
1619 while (to_free_normal > 0 || to_free_highmem > 0) {
1620 unsigned long pfn = memory_bm_next_pfn(©_bm);
1621 struct page *page = pfn_to_page(pfn);
1622
1623 if (PageHighMem(page)) {
1624 if (!to_free_highmem)
1625 continue;
1626 to_free_highmem--;
1627 alloc_highmem--;
1628 } else {
1629 if (!to_free_normal)
1630 continue;
1631 to_free_normal--;
1632 alloc_normal--;
1633 }
1634 memory_bm_clear_bit(©_bm, pfn);
1635 swsusp_unset_page_forbidden(page);
1636 swsusp_unset_page_free(page);
1637 __free_page(page);
1638 }
1639
1640 return free;
1641}
1642
1643/**
1644 * minimum_image_size - Estimate the minimum acceptable size of an image.
1645 * @saveable: Number of saveable pages in the system.
1646 *
1647 * We want to avoid attempting to free too much memory too hard, so estimate the
1648 * minimum acceptable size of a hibernation image to use as the lower limit for
1649 * preallocating memory.
1650 *
1651 * We assume that the minimum image size should be proportional to
1652 *
1653 * [number of saveable pages] - [number of pages that can be freed in theory]
1654 *
1655 * where the second term is the sum of (1) reclaimable slab pages, (2) active
1656 * and (3) inactive anonymous pages, (4) active and (5) inactive file pages.
1657 */
1658static unsigned long minimum_image_size(unsigned long saveable)
1659{
1660 unsigned long size;
1661
1662 size = global_node_page_state(NR_SLAB_RECLAIMABLE)
1663 + global_node_page_state(NR_ACTIVE_ANON)
1664 + global_node_page_state(NR_INACTIVE_ANON)
1665 + global_node_page_state(NR_ACTIVE_FILE)
1666 + global_node_page_state(NR_INACTIVE_FILE);
1667
1668 return saveable <= size ? 0 : saveable - size;
1669}
1670
1671/**
1672 * hibernate_preallocate_memory - Preallocate memory for hibernation image.
1673 *
1674 * To create a hibernation image it is necessary to make a copy of every page
1675 * frame in use. We also need a number of page frames to be free during
1676 * hibernation for allocations made while saving the image and for device
1677 * drivers, in case they need to allocate memory from their hibernation
1678 * callbacks (these two numbers are given by PAGES_FOR_IO (which is a rough
1679 * estimate) and reserverd_size divided by PAGE_SIZE (which is tunable through
1680 * /sys/power/reserved_size, respectively). To make this happen, we compute the
1681 * total number of available page frames and allocate at least
1682 *
1683 * ([page frames total] + PAGES_FOR_IO + [metadata pages]) / 2
1684 * + 2 * DIV_ROUND_UP(reserved_size, PAGE_SIZE)
1685 *
1686 * of them, which corresponds to the maximum size of a hibernation image.
1687 *
1688 * If image_size is set below the number following from the above formula,
1689 * the preallocation of memory is continued until the total number of saveable
1690 * pages in the system is below the requested image size or the minimum
1691 * acceptable image size returned by minimum_image_size(), whichever is greater.
1692 */
1693int hibernate_preallocate_memory(void)
1694{
1695 struct zone *zone;
1696 unsigned long saveable, size, max_size, count, highmem, pages = 0;
1697 unsigned long alloc, save_highmem, pages_highmem, avail_normal;
1698 ktime_t start, stop;
1699 int error;
1700
1701 pr_info("Preallocating image memory... ");
1702 start = ktime_get();
1703
1704 error = memory_bm_create(&orig_bm, GFP_IMAGE, PG_ANY);
1705 if (error)
1706 goto err_out;
1707
1708 error = memory_bm_create(©_bm, GFP_IMAGE, PG_ANY);
1709 if (error)
1710 goto err_out;
1711
1712 alloc_normal = 0;
1713 alloc_highmem = 0;
1714
1715 /* Count the number of saveable data pages. */
1716 save_highmem = count_highmem_pages();
1717 saveable = count_data_pages();
1718
1719 /*
1720 * Compute the total number of page frames we can use (count) and the
1721 * number of pages needed for image metadata (size).
1722 */
1723 count = saveable;
1724 saveable += save_highmem;
1725 highmem = save_highmem;
1726 size = 0;
1727 for_each_populated_zone(zone) {
1728 size += snapshot_additional_pages(zone);
1729 if (is_highmem(zone))
1730 highmem += zone_page_state(zone, NR_FREE_PAGES);
1731 else
1732 count += zone_page_state(zone, NR_FREE_PAGES);
1733 }
1734 avail_normal = count;
1735 count += highmem;
1736 count -= totalreserve_pages;
1737
1738 /* Add number of pages required for page keys (s390 only). */
1739 size += page_key_additional_pages(saveable);
1740
1741 /* Compute the maximum number of saveable pages to leave in memory. */
1742 max_size = (count - (size + PAGES_FOR_IO)) / 2
1743 - 2 * DIV_ROUND_UP(reserved_size, PAGE_SIZE);
1744 /* Compute the desired number of image pages specified by image_size. */
1745 size = DIV_ROUND_UP(image_size, PAGE_SIZE);
1746 if (size > max_size)
1747 size = max_size;
1748 /*
1749 * If the desired number of image pages is at least as large as the
1750 * current number of saveable pages in memory, allocate page frames for
1751 * the image and we're done.
1752 */
1753 if (size >= saveable) {
1754 pages = preallocate_image_highmem(save_highmem);
1755 pages += preallocate_image_memory(saveable - pages, avail_normal);
1756 goto out;
1757 }
1758
1759 /* Estimate the minimum size of the image. */
1760 pages = minimum_image_size(saveable);
1761 /*
1762 * To avoid excessive pressure on the normal zone, leave room in it to
1763 * accommodate an image of the minimum size (unless it's already too
1764 * small, in which case don't preallocate pages from it at all).
1765 */
1766 if (avail_normal > pages)
1767 avail_normal -= pages;
1768 else
1769 avail_normal = 0;
1770 if (size < pages)
1771 size = min_t(unsigned long, pages, max_size);
1772
1773 /*
1774 * Let the memory management subsystem know that we're going to need a
1775 * large number of page frames to allocate and make it free some memory.
1776 * NOTE: If this is not done, performance will be hurt badly in some
1777 * test cases.
1778 */
1779 shrink_all_memory(saveable - size);
1780
1781 /*
1782 * The number of saveable pages in memory was too high, so apply some
1783 * pressure to decrease it. First, make room for the largest possible
1784 * image and fail if that doesn't work. Next, try to decrease the size
1785 * of the image as much as indicated by 'size' using allocations from
1786 * highmem and non-highmem zones separately.
1787 */
1788 pages_highmem = preallocate_image_highmem(highmem / 2);
1789 alloc = count - max_size;
1790 if (alloc > pages_highmem)
1791 alloc -= pages_highmem;
1792 else
1793 alloc = 0;
1794 pages = preallocate_image_memory(alloc, avail_normal);
1795 if (pages < alloc) {
1796 /* We have exhausted non-highmem pages, try highmem. */
1797 alloc -= pages;
1798 pages += pages_highmem;
1799 pages_highmem = preallocate_image_highmem(alloc);
1800 if (pages_highmem < alloc)
1801 goto err_out;
1802 pages += pages_highmem;
1803 /*
1804 * size is the desired number of saveable pages to leave in
1805 * memory, so try to preallocate (all memory - size) pages.
1806 */
1807 alloc = (count - pages) - size;
1808 pages += preallocate_image_highmem(alloc);
1809 } else {
1810 /*
1811 * There are approximately max_size saveable pages at this point
1812 * and we want to reduce this number down to size.
1813 */
1814 alloc = max_size - size;
1815 size = preallocate_highmem_fraction(alloc, highmem, count);
1816 pages_highmem += size;
1817 alloc -= size;
1818 size = preallocate_image_memory(alloc, avail_normal);
1819 pages_highmem += preallocate_image_highmem(alloc - size);
1820 pages += pages_highmem + size;
1821 }
1822
1823 /*
1824 * We only need as many page frames for the image as there are saveable
1825 * pages in memory, but we have allocated more. Release the excessive
1826 * ones now.
1827 */
1828 pages -= free_unnecessary_pages();
1829
1830 out:
1831 stop = ktime_get();
1832 pr_cont("done (allocated %lu pages)\n", pages);
1833 swsusp_show_speed(start, stop, pages, "Allocated");
1834
1835 return 0;
1836
1837 err_out:
1838 pr_cont("\n");
1839 swsusp_free();
1840 return -ENOMEM;
1841}
1842
1843#ifdef CONFIG_HIGHMEM
1844/**
1845 * count_pages_for_highmem - Count non-highmem pages needed for copying highmem.
1846 *
1847 * Compute the number of non-highmem pages that will be necessary for creating
1848 * copies of highmem pages.
1849 */
1850static unsigned int count_pages_for_highmem(unsigned int nr_highmem)
1851{
1852 unsigned int free_highmem = count_free_highmem_pages() + alloc_highmem;
1853
1854 if (free_highmem >= nr_highmem)
1855 nr_highmem = 0;
1856 else
1857 nr_highmem -= free_highmem;
1858
1859 return nr_highmem;
1860}
1861#else
1862static unsigned int count_pages_for_highmem(unsigned int nr_highmem) { return 0; }
1863#endif /* CONFIG_HIGHMEM */
1864
1865/**
1866 * enough_free_mem - Check if there is enough free memory for the image.
1867 */
1868static int enough_free_mem(unsigned int nr_pages, unsigned int nr_highmem)
1869{
1870 struct zone *zone;
1871 unsigned int free = alloc_normal;
1872
1873 for_each_populated_zone(zone)
1874 if (!is_highmem(zone))
1875 free += zone_page_state(zone, NR_FREE_PAGES);
1876
1877 nr_pages += count_pages_for_highmem(nr_highmem);
1878 pr_debug("Normal pages needed: %u + %u, available pages: %u\n",
1879 nr_pages, PAGES_FOR_IO, free);
1880
1881 return free > nr_pages + PAGES_FOR_IO;
1882}
1883
1884#ifdef CONFIG_HIGHMEM
1885/**
1886 * get_highmem_buffer - Allocate a buffer for highmem pages.
1887 *
1888 * If there are some highmem pages in the hibernation image, we may need a
1889 * buffer to copy them and/or load their data.
1890 */
1891static inline int get_highmem_buffer(int safe_needed)
1892{
1893 buffer = get_image_page(GFP_ATOMIC, safe_needed);
1894 return buffer ? 0 : -ENOMEM;
1895}
1896
1897/**
1898 * alloc_highmem_image_pages - Allocate some highmem pages for the image.
1899 *
1900 * Try to allocate as many pages as needed, but if the number of free highmem
1901 * pages is less than that, allocate them all.
1902 */
1903static inline unsigned int alloc_highmem_pages(struct memory_bitmap *bm,
1904 unsigned int nr_highmem)
1905{
1906 unsigned int to_alloc = count_free_highmem_pages();
1907
1908 if (to_alloc > nr_highmem)
1909 to_alloc = nr_highmem;
1910
1911 nr_highmem -= to_alloc;
1912 while (to_alloc-- > 0) {
1913 struct page *page;
1914
1915 page = alloc_image_page(__GFP_HIGHMEM|__GFP_KSWAPD_RECLAIM);
1916 memory_bm_set_bit(bm, page_to_pfn(page));
1917 }
1918 return nr_highmem;
1919}
1920#else
1921static inline int get_highmem_buffer(int safe_needed) { return 0; }
1922
1923static inline unsigned int alloc_highmem_pages(struct memory_bitmap *bm,
1924 unsigned int n) { return 0; }
1925#endif /* CONFIG_HIGHMEM */
1926
1927/**
1928 * swsusp_alloc - Allocate memory for hibernation image.
1929 *
1930 * We first try to allocate as many highmem pages as there are
1931 * saveable highmem pages in the system. If that fails, we allocate
1932 * non-highmem pages for the copies of the remaining highmem ones.
1933 *
1934 * In this approach it is likely that the copies of highmem pages will
1935 * also be located in the high memory, because of the way in which
1936 * copy_data_pages() works.
1937 */
1938static int swsusp_alloc(struct memory_bitmap *copy_bm,
1939 unsigned int nr_pages, unsigned int nr_highmem)
1940{
1941 if (nr_highmem > 0) {
1942 if (get_highmem_buffer(PG_ANY))
1943 goto err_out;
1944 if (nr_highmem > alloc_highmem) {
1945 nr_highmem -= alloc_highmem;
1946 nr_pages += alloc_highmem_pages(copy_bm, nr_highmem);
1947 }
1948 }
1949 if (nr_pages > alloc_normal) {
1950 nr_pages -= alloc_normal;
1951 while (nr_pages-- > 0) {
1952 struct page *page;
1953
1954 page = alloc_image_page(GFP_ATOMIC);
1955 if (!page)
1956 goto err_out;
1957 memory_bm_set_bit(copy_bm, page_to_pfn(page));
1958 }
1959 }
1960
1961 return 0;
1962
1963 err_out:
1964 swsusp_free();
1965 return -ENOMEM;
1966}
1967
1968asmlinkage __visible int swsusp_save(void)
1969{
1970 unsigned int nr_pages, nr_highmem;
1971
1972 pr_info("Creating hibernation image:\n");
1973
1974 drain_local_pages(NULL);
1975 nr_pages = count_data_pages();
1976 nr_highmem = count_highmem_pages();
1977 pr_info("Need to copy %u pages\n", nr_pages + nr_highmem);
1978
1979 if (!enough_free_mem(nr_pages, nr_highmem)) {
1980 pr_err("Not enough free memory\n");
1981 return -ENOMEM;
1982 }
1983
1984 if (swsusp_alloc(©_bm, nr_pages, nr_highmem)) {
1985 pr_err("Memory allocation failed\n");
1986 return -ENOMEM;
1987 }
1988
1989 /*
1990 * During allocating of suspend pagedir, new cold pages may appear.
1991 * Kill them.
1992 */
1993 drain_local_pages(NULL);
1994 copy_data_pages(©_bm, &orig_bm);
1995
1996 /*
1997 * End of critical section. From now on, we can write to memory,
1998 * but we should not touch disk. This specially means we must _not_
1999 * touch swap space! Except we must write out our image of course.
2000 */
2001
2002 nr_pages += nr_highmem;
2003 nr_copy_pages = nr_pages;
2004 nr_meta_pages = DIV_ROUND_UP(nr_pages * sizeof(long), PAGE_SIZE);
2005
2006 pr_info("Hibernation image created (%d pages copied)\n", nr_pages);
2007
2008 return 0;
2009}
2010
2011#ifndef CONFIG_ARCH_HIBERNATION_HEADER
2012static int init_header_complete(struct swsusp_info *info)
2013{
2014 memcpy(&info->uts, init_utsname(), sizeof(struct new_utsname));
2015 info->version_code = LINUX_VERSION_CODE;
2016 return 0;
2017}
2018
2019static char *check_image_kernel(struct swsusp_info *info)
2020{
2021 if (info->version_code != LINUX_VERSION_CODE)
2022 return "kernel version";
2023 if (strcmp(info->uts.sysname,init_utsname()->sysname))
2024 return "system type";
2025 if (strcmp(info->uts.release,init_utsname()->release))
2026 return "kernel release";
2027 if (strcmp(info->uts.version,init_utsname()->version))
2028 return "version";
2029 if (strcmp(info->uts.machine,init_utsname()->machine))
2030 return "machine";
2031 return NULL;
2032}
2033#endif /* CONFIG_ARCH_HIBERNATION_HEADER */
2034
2035unsigned long snapshot_get_image_size(void)
2036{
2037 return nr_copy_pages + nr_meta_pages + 1;
2038}
2039
2040static int init_header(struct swsusp_info *info)
2041{
2042 memset(info, 0, sizeof(struct swsusp_info));
2043 info->num_physpages = get_num_physpages();
2044 info->image_pages = nr_copy_pages;
2045 info->pages = snapshot_get_image_size();
2046 info->size = info->pages;
2047 info->size <<= PAGE_SHIFT;
2048 return init_header_complete(info);
2049}
2050
2051/**
2052 * pack_pfns - Prepare PFNs for saving.
2053 * @bm: Memory bitmap.
2054 * @buf: Memory buffer to store the PFNs in.
2055 *
2056 * PFNs corresponding to set bits in @bm are stored in the area of memory
2057 * pointed to by @buf (1 page at a time).
2058 */
2059static inline void pack_pfns(unsigned long *buf, struct memory_bitmap *bm)
2060{
2061 int j;
2062
2063 for (j = 0; j < PAGE_SIZE / sizeof(long); j++) {
2064 buf[j] = memory_bm_next_pfn(bm);
2065 if (unlikely(buf[j] == BM_END_OF_MAP))
2066 break;
2067 /* Save page key for data page (s390 only). */
2068 page_key_read(buf + j);
2069 }
2070}
2071
2072/**
2073 * snapshot_read_next - Get the address to read the next image page from.
2074 * @handle: Snapshot handle to be used for the reading.
2075 *
2076 * On the first call, @handle should point to a zeroed snapshot_handle
2077 * structure. The structure gets populated then and a pointer to it should be
2078 * passed to this function every next time.
2079 *
2080 * On success, the function returns a positive number. Then, the caller
2081 * is allowed to read up to the returned number of bytes from the memory
2082 * location computed by the data_of() macro.
2083 *
2084 * The function returns 0 to indicate the end of the data stream condition,
2085 * and negative numbers are returned on errors. If that happens, the structure
2086 * pointed to by @handle is not updated and should not be used any more.
2087 */
2088int snapshot_read_next(struct snapshot_handle *handle)
2089{
2090 if (handle->cur > nr_meta_pages + nr_copy_pages)
2091 return 0;
2092
2093 if (!buffer) {
2094 /* This makes the buffer be freed by swsusp_free() */
2095 buffer = get_image_page(GFP_ATOMIC, PG_ANY);
2096 if (!buffer)
2097 return -ENOMEM;
2098 }
2099 if (!handle->cur) {
2100 int error;
2101
2102 error = init_header((struct swsusp_info *)buffer);
2103 if (error)
2104 return error;
2105 handle->buffer = buffer;
2106 memory_bm_position_reset(&orig_bm);
2107 memory_bm_position_reset(©_bm);
2108 } else if (handle->cur <= nr_meta_pages) {
2109 clear_page(buffer);
2110 pack_pfns(buffer, &orig_bm);
2111 } else {
2112 struct page *page;
2113
2114 page = pfn_to_page(memory_bm_next_pfn(©_bm));
2115 if (PageHighMem(page)) {
2116 /*
2117 * Highmem pages are copied to the buffer,
2118 * because we can't return with a kmapped
2119 * highmem page (we may not be called again).
2120 */
2121 void *kaddr;
2122
2123 kaddr = kmap_atomic(page);
2124 copy_page(buffer, kaddr);
2125 kunmap_atomic(kaddr);
2126 handle->buffer = buffer;
2127 } else {
2128 handle->buffer = page_address(page);
2129 }
2130 }
2131 handle->cur++;
2132 return PAGE_SIZE;
2133}
2134
2135static void duplicate_memory_bitmap(struct memory_bitmap *dst,
2136 struct memory_bitmap *src)
2137{
2138 unsigned long pfn;
2139
2140 memory_bm_position_reset(src);
2141 pfn = memory_bm_next_pfn(src);
2142 while (pfn != BM_END_OF_MAP) {
2143 memory_bm_set_bit(dst, pfn);
2144 pfn = memory_bm_next_pfn(src);
2145 }
2146}
2147
2148/**
2149 * mark_unsafe_pages - Mark pages that were used before hibernation.
2150 *
2151 * Mark the pages that cannot be used for storing the image during restoration,
2152 * because they conflict with the pages that had been used before hibernation.
2153 */
2154static void mark_unsafe_pages(struct memory_bitmap *bm)
2155{
2156 unsigned long pfn;
2157
2158 /* Clear the "free"/"unsafe" bit for all PFNs */
2159 memory_bm_position_reset(free_pages_map);
2160 pfn = memory_bm_next_pfn(free_pages_map);
2161 while (pfn != BM_END_OF_MAP) {
2162 memory_bm_clear_current(free_pages_map);
2163 pfn = memory_bm_next_pfn(free_pages_map);
2164 }
2165
2166 /* Mark pages that correspond to the "original" PFNs as "unsafe" */
2167 duplicate_memory_bitmap(free_pages_map, bm);
2168
2169 allocated_unsafe_pages = 0;
2170}
2171
2172static int check_header(struct swsusp_info *info)
2173{
2174 char *reason;
2175
2176 reason = check_image_kernel(info);
2177 if (!reason && info->num_physpages != get_num_physpages())
2178 reason = "memory size";
2179 if (reason) {
2180 pr_err("Image mismatch: %s\n", reason);
2181 return -EPERM;
2182 }
2183 return 0;
2184}
2185
2186/**
2187 * load header - Check the image header and copy the data from it.
2188 */
2189static int load_header(struct swsusp_info *info)
2190{
2191 int error;
2192
2193 restore_pblist = NULL;
2194 error = check_header(info);
2195 if (!error) {
2196 nr_copy_pages = info->image_pages;
2197 nr_meta_pages = info->pages - info->image_pages - 1;
2198 }
2199 return error;
2200}
2201
2202/**
2203 * unpack_orig_pfns - Set bits corresponding to given PFNs in a memory bitmap.
2204 * @bm: Memory bitmap.
2205 * @buf: Area of memory containing the PFNs.
2206 *
2207 * For each element of the array pointed to by @buf (1 page at a time), set the
2208 * corresponding bit in @bm.
2209 */
2210static int unpack_orig_pfns(unsigned long *buf, struct memory_bitmap *bm)
2211{
2212 int j;
2213
2214 for (j = 0; j < PAGE_SIZE / sizeof(long); j++) {
2215 if (unlikely(buf[j] == BM_END_OF_MAP))
2216 break;
2217
2218 /* Extract and buffer page key for data page (s390 only). */
2219 page_key_memorize(buf + j);
2220
2221 if (pfn_valid(buf[j]) && memory_bm_pfn_present(bm, buf[j]))
2222 memory_bm_set_bit(bm, buf[j]);
2223 else
2224 return -EFAULT;
2225 }
2226
2227 return 0;
2228}
2229
2230#ifdef CONFIG_HIGHMEM
2231/*
2232 * struct highmem_pbe is used for creating the list of highmem pages that
2233 * should be restored atomically during the resume from disk, because the page
2234 * frames they have occupied before the suspend are in use.
2235 */
2236struct highmem_pbe {
2237 struct page *copy_page; /* data is here now */
2238 struct page *orig_page; /* data was here before the suspend */
2239 struct highmem_pbe *next;
2240};
2241
2242/*
2243 * List of highmem PBEs needed for restoring the highmem pages that were
2244 * allocated before the suspend and included in the suspend image, but have
2245 * also been allocated by the "resume" kernel, so their contents cannot be
2246 * written directly to their "original" page frames.
2247 */
2248static struct highmem_pbe *highmem_pblist;
2249
2250/**
2251 * count_highmem_image_pages - Compute the number of highmem pages in the image.
2252 * @bm: Memory bitmap.
2253 *
2254 * The bits in @bm that correspond to image pages are assumed to be set.
2255 */
2256static unsigned int count_highmem_image_pages(struct memory_bitmap *bm)
2257{
2258 unsigned long pfn;
2259 unsigned int cnt = 0;
2260
2261 memory_bm_position_reset(bm);
2262 pfn = memory_bm_next_pfn(bm);
2263 while (pfn != BM_END_OF_MAP) {
2264 if (PageHighMem(pfn_to_page(pfn)))
2265 cnt++;
2266
2267 pfn = memory_bm_next_pfn(bm);
2268 }
2269 return cnt;
2270}
2271
2272static unsigned int safe_highmem_pages;
2273
2274static struct memory_bitmap *safe_highmem_bm;
2275
2276/**
2277 * prepare_highmem_image - Allocate memory for loading highmem data from image.
2278 * @bm: Pointer to an uninitialized memory bitmap structure.
2279 * @nr_highmem_p: Pointer to the number of highmem image pages.
2280 *
2281 * Try to allocate as many highmem pages as there are highmem image pages
2282 * (@nr_highmem_p points to the variable containing the number of highmem image
2283 * pages). The pages that are "safe" (ie. will not be overwritten when the
2284 * hibernation image is restored entirely) have the corresponding bits set in
2285 * @bm (it must be unitialized).
2286 *
2287 * NOTE: This function should not be called if there are no highmem image pages.
2288 */
2289static int prepare_highmem_image(struct memory_bitmap *bm,
2290 unsigned int *nr_highmem_p)
2291{
2292 unsigned int to_alloc;
2293
2294 if (memory_bm_create(bm, GFP_ATOMIC, PG_SAFE))
2295 return -ENOMEM;
2296
2297 if (get_highmem_buffer(PG_SAFE))
2298 return -ENOMEM;
2299
2300 to_alloc = count_free_highmem_pages();
2301 if (to_alloc > *nr_highmem_p)
2302 to_alloc = *nr_highmem_p;
2303 else
2304 *nr_highmem_p = to_alloc;
2305
2306 safe_highmem_pages = 0;
2307 while (to_alloc-- > 0) {
2308 struct page *page;
2309
2310 page = alloc_page(__GFP_HIGHMEM);
2311 if (!swsusp_page_is_free(page)) {
2312 /* The page is "safe", set its bit the bitmap */
2313 memory_bm_set_bit(bm, page_to_pfn(page));
2314 safe_highmem_pages++;
2315 }
2316 /* Mark the page as allocated */
2317 swsusp_set_page_forbidden(page);
2318 swsusp_set_page_free(page);
2319 }
2320 memory_bm_position_reset(bm);
2321 safe_highmem_bm = bm;
2322 return 0;
2323}
2324
2325static struct page *last_highmem_page;
2326
2327/**
2328 * get_highmem_page_buffer - Prepare a buffer to store a highmem image page.
2329 *
2330 * For a given highmem image page get a buffer that suspend_write_next() should
2331 * return to its caller to write to.
2332 *
2333 * If the page is to be saved to its "original" page frame or a copy of
2334 * the page is to be made in the highmem, @buffer is returned. Otherwise,
2335 * the copy of the page is to be made in normal memory, so the address of
2336 * the copy is returned.
2337 *
2338 * If @buffer is returned, the caller of suspend_write_next() will write
2339 * the page's contents to @buffer, so they will have to be copied to the
2340 * right location on the next call to suspend_write_next() and it is done
2341 * with the help of copy_last_highmem_page(). For this purpose, if
2342 * @buffer is returned, @last_highmem_page is set to the page to which
2343 * the data will have to be copied from @buffer.
2344 */
2345static void *get_highmem_page_buffer(struct page *page,
2346 struct chain_allocator *ca)
2347{
2348 struct highmem_pbe *pbe;
2349 void *kaddr;
2350
2351 if (swsusp_page_is_forbidden(page) && swsusp_page_is_free(page)) {
2352 /*
2353 * We have allocated the "original" page frame and we can
2354 * use it directly to store the loaded page.
2355 */
2356 last_highmem_page = page;
2357 return buffer;
2358 }
2359 /*
2360 * The "original" page frame has not been allocated and we have to
2361 * use a "safe" page frame to store the loaded page.
2362 */
2363 pbe = chain_alloc(ca, sizeof(struct highmem_pbe));
2364 if (!pbe) {
2365 swsusp_free();
2366 return ERR_PTR(-ENOMEM);
2367 }
2368 pbe->orig_page = page;
2369 if (safe_highmem_pages > 0) {
2370 struct page *tmp;
2371
2372 /* Copy of the page will be stored in high memory */
2373 kaddr = buffer;
2374 tmp = pfn_to_page(memory_bm_next_pfn(safe_highmem_bm));
2375 safe_highmem_pages--;
2376 last_highmem_page = tmp;
2377 pbe->copy_page = tmp;
2378 } else {
2379 /* Copy of the page will be stored in normal memory */
2380 kaddr = safe_pages_list;
2381 safe_pages_list = safe_pages_list->next;
2382 pbe->copy_page = virt_to_page(kaddr);
2383 }
2384 pbe->next = highmem_pblist;
2385 highmem_pblist = pbe;
2386 return kaddr;
2387}
2388
2389/**
2390 * copy_last_highmem_page - Copy most the most recent highmem image page.
2391 *
2392 * Copy the contents of a highmem image from @buffer, where the caller of
2393 * snapshot_write_next() has stored them, to the right location represented by
2394 * @last_highmem_page .
2395 */
2396static void copy_last_highmem_page(void)
2397{
2398 if (last_highmem_page) {
2399 void *dst;
2400
2401 dst = kmap_atomic(last_highmem_page);
2402 copy_page(dst, buffer);
2403 kunmap_atomic(dst);
2404 last_highmem_page = NULL;
2405 }
2406}
2407
2408static inline int last_highmem_page_copied(void)
2409{
2410 return !last_highmem_page;
2411}
2412
2413static inline void free_highmem_data(void)
2414{
2415 if (safe_highmem_bm)
2416 memory_bm_free(safe_highmem_bm, PG_UNSAFE_CLEAR);
2417
2418 if (buffer)
2419 free_image_page(buffer, PG_UNSAFE_CLEAR);
2420}
2421#else
2422static unsigned int count_highmem_image_pages(struct memory_bitmap *bm) { return 0; }
2423
2424static inline int prepare_highmem_image(struct memory_bitmap *bm,
2425 unsigned int *nr_highmem_p) { return 0; }
2426
2427static inline void *get_highmem_page_buffer(struct page *page,
2428 struct chain_allocator *ca)
2429{
2430 return ERR_PTR(-EINVAL);
2431}
2432
2433static inline void copy_last_highmem_page(void) {}
2434static inline int last_highmem_page_copied(void) { return 1; }
2435static inline void free_highmem_data(void) {}
2436#endif /* CONFIG_HIGHMEM */
2437
2438#define PBES_PER_LINKED_PAGE (LINKED_PAGE_DATA_SIZE / sizeof(struct pbe))
2439
2440/**
2441 * prepare_image - Make room for loading hibernation image.
2442 * @new_bm: Unitialized memory bitmap structure.
2443 * @bm: Memory bitmap with unsafe pages marked.
2444 *
2445 * Use @bm to mark the pages that will be overwritten in the process of
2446 * restoring the system memory state from the suspend image ("unsafe" pages)
2447 * and allocate memory for the image.
2448 *
2449 * The idea is to allocate a new memory bitmap first and then allocate
2450 * as many pages as needed for image data, but without specifying what those
2451 * pages will be used for just yet. Instead, we mark them all as allocated and
2452 * create a lists of "safe" pages to be used later. On systems with high
2453 * memory a list of "safe" highmem pages is created too.
2454 */
2455static int prepare_image(struct memory_bitmap *new_bm, struct memory_bitmap *bm)
2456{
2457 unsigned int nr_pages, nr_highmem;
2458 struct linked_page *lp;
2459 int error;
2460
2461 /* If there is no highmem, the buffer will not be necessary */
2462 free_image_page(buffer, PG_UNSAFE_CLEAR);
2463 buffer = NULL;
2464
2465 nr_highmem = count_highmem_image_pages(bm);
2466 mark_unsafe_pages(bm);
2467
2468 error = memory_bm_create(new_bm, GFP_ATOMIC, PG_SAFE);
2469 if (error)
2470 goto Free;
2471
2472 duplicate_memory_bitmap(new_bm, bm);
2473 memory_bm_free(bm, PG_UNSAFE_KEEP);
2474 if (nr_highmem > 0) {
2475 error = prepare_highmem_image(bm, &nr_highmem);
2476 if (error)
2477 goto Free;
2478 }
2479 /*
2480 * Reserve some safe pages for potential later use.
2481 *
2482 * NOTE: This way we make sure there will be enough safe pages for the
2483 * chain_alloc() in get_buffer(). It is a bit wasteful, but
2484 * nr_copy_pages cannot be greater than 50% of the memory anyway.
2485 *
2486 * nr_copy_pages cannot be less than allocated_unsafe_pages too.
2487 */
2488 nr_pages = nr_copy_pages - nr_highmem - allocated_unsafe_pages;
2489 nr_pages = DIV_ROUND_UP(nr_pages, PBES_PER_LINKED_PAGE);
2490 while (nr_pages > 0) {
2491 lp = get_image_page(GFP_ATOMIC, PG_SAFE);
2492 if (!lp) {
2493 error = -ENOMEM;
2494 goto Free;
2495 }
2496 lp->next = safe_pages_list;
2497 safe_pages_list = lp;
2498 nr_pages--;
2499 }
2500 /* Preallocate memory for the image */
2501 nr_pages = nr_copy_pages - nr_highmem - allocated_unsafe_pages;
2502 while (nr_pages > 0) {
2503 lp = (struct linked_page *)get_zeroed_page(GFP_ATOMIC);
2504 if (!lp) {
2505 error = -ENOMEM;
2506 goto Free;
2507 }
2508 if (!swsusp_page_is_free(virt_to_page(lp))) {
2509 /* The page is "safe", add it to the list */
2510 lp->next = safe_pages_list;
2511 safe_pages_list = lp;
2512 }
2513 /* Mark the page as allocated */
2514 swsusp_set_page_forbidden(virt_to_page(lp));
2515 swsusp_set_page_free(virt_to_page(lp));
2516 nr_pages--;
2517 }
2518 return 0;
2519
2520 Free:
2521 swsusp_free();
2522 return error;
2523}
2524
2525/**
2526 * get_buffer - Get the address to store the next image data page.
2527 *
2528 * Get the address that snapshot_write_next() should return to its caller to
2529 * write to.
2530 */
2531static void *get_buffer(struct memory_bitmap *bm, struct chain_allocator *ca)
2532{
2533 struct pbe *pbe;
2534 struct page *page;
2535 unsigned long pfn = memory_bm_next_pfn(bm);
2536
2537 if (pfn == BM_END_OF_MAP)
2538 return ERR_PTR(-EFAULT);
2539
2540 page = pfn_to_page(pfn);
2541 if (PageHighMem(page))
2542 return get_highmem_page_buffer(page, ca);
2543
2544 if (swsusp_page_is_forbidden(page) && swsusp_page_is_free(page))
2545 /*
2546 * We have allocated the "original" page frame and we can
2547 * use it directly to store the loaded page.
2548 */
2549 return page_address(page);
2550
2551 /*
2552 * The "original" page frame has not been allocated and we have to
2553 * use a "safe" page frame to store the loaded page.
2554 */
2555 pbe = chain_alloc(ca, sizeof(struct pbe));
2556 if (!pbe) {
2557 swsusp_free();
2558 return ERR_PTR(-ENOMEM);
2559 }
2560 pbe->orig_address = page_address(page);
2561 pbe->address = safe_pages_list;
2562 safe_pages_list = safe_pages_list->next;
2563 pbe->next = restore_pblist;
2564 restore_pblist = pbe;
2565 return pbe->address;
2566}
2567
2568/**
2569 * snapshot_write_next - Get the address to store the next image page.
2570 * @handle: Snapshot handle structure to guide the writing.
2571 *
2572 * On the first call, @handle should point to a zeroed snapshot_handle
2573 * structure. The structure gets populated then and a pointer to it should be
2574 * passed to this function every next time.
2575 *
2576 * On success, the function returns a positive number. Then, the caller
2577 * is allowed to write up to the returned number of bytes to the memory
2578 * location computed by the data_of() macro.
2579 *
2580 * The function returns 0 to indicate the "end of file" condition. Negative
2581 * numbers are returned on errors, in which cases the structure pointed to by
2582 * @handle is not updated and should not be used any more.
2583 */
2584int snapshot_write_next(struct snapshot_handle *handle)
2585{
2586 static struct chain_allocator ca;
2587 int error = 0;
2588
2589 /* Check if we have already loaded the entire image */
2590 if (handle->cur > 1 && handle->cur > nr_meta_pages + nr_copy_pages)
2591 return 0;
2592
2593 handle->sync_read = 1;
2594
2595 if (!handle->cur) {
2596 if (!buffer)
2597 /* This makes the buffer be freed by swsusp_free() */
2598 buffer = get_image_page(GFP_ATOMIC, PG_ANY);
2599
2600 if (!buffer)
2601 return -ENOMEM;
2602
2603 handle->buffer = buffer;
2604 } else if (handle->cur == 1) {
2605 error = load_header(buffer);
2606 if (error)
2607 return error;
2608
2609 safe_pages_list = NULL;
2610
2611 error = memory_bm_create(©_bm, GFP_ATOMIC, PG_ANY);
2612 if (error)
2613 return error;
2614
2615 /* Allocate buffer for page keys. */
2616 error = page_key_alloc(nr_copy_pages);
2617 if (error)
2618 return error;
2619
2620 hibernate_restore_protection_begin();
2621 } else if (handle->cur <= nr_meta_pages + 1) {
2622 error = unpack_orig_pfns(buffer, ©_bm);
2623 if (error)
2624 return error;
2625
2626 if (handle->cur == nr_meta_pages + 1) {
2627 error = prepare_image(&orig_bm, ©_bm);
2628 if (error)
2629 return error;
2630
2631 chain_init(&ca, GFP_ATOMIC, PG_SAFE);
2632 memory_bm_position_reset(&orig_bm);
2633 restore_pblist = NULL;
2634 handle->buffer = get_buffer(&orig_bm, &ca);
2635 handle->sync_read = 0;
2636 if (IS_ERR(handle->buffer))
2637 return PTR_ERR(handle->buffer);
2638 }
2639 } else {
2640 copy_last_highmem_page();
2641 /* Restore page key for data page (s390 only). */
2642 page_key_write(handle->buffer);
2643 hibernate_restore_protect_page(handle->buffer);
2644 handle->buffer = get_buffer(&orig_bm, &ca);
2645 if (IS_ERR(handle->buffer))
2646 return PTR_ERR(handle->buffer);
2647 if (handle->buffer != buffer)
2648 handle->sync_read = 0;
2649 }
2650 handle->cur++;
2651 return PAGE_SIZE;
2652}
2653
2654/**
2655 * snapshot_write_finalize - Complete the loading of a hibernation image.
2656 *
2657 * Must be called after the last call to snapshot_write_next() in case the last
2658 * page in the image happens to be a highmem page and its contents should be
2659 * stored in highmem. Additionally, it recycles bitmap memory that's not
2660 * necessary any more.
2661 */
2662void snapshot_write_finalize(struct snapshot_handle *handle)
2663{
2664 copy_last_highmem_page();
2665 /* Restore page key for data page (s390 only). */
2666 page_key_write(handle->buffer);
2667 page_key_free();
2668 hibernate_restore_protect_page(handle->buffer);
2669 /* Do that only if we have loaded the image entirely */
2670 if (handle->cur > 1 && handle->cur > nr_meta_pages + nr_copy_pages) {
2671 memory_bm_recycle(&orig_bm);
2672 free_highmem_data();
2673 }
2674}
2675
2676int snapshot_image_loaded(struct snapshot_handle *handle)
2677{
2678 return !(!nr_copy_pages || !last_highmem_page_copied() ||
2679 handle->cur <= nr_meta_pages + nr_copy_pages);
2680}
2681
2682#ifdef CONFIG_HIGHMEM
2683/* Assumes that @buf is ready and points to a "safe" page */
2684static inline void swap_two_pages_data(struct page *p1, struct page *p2,
2685 void *buf)
2686{
2687 void *kaddr1, *kaddr2;
2688
2689 kaddr1 = kmap_atomic(p1);
2690 kaddr2 = kmap_atomic(p2);
2691 copy_page(buf, kaddr1);
2692 copy_page(kaddr1, kaddr2);
2693 copy_page(kaddr2, buf);
2694 kunmap_atomic(kaddr2);
2695 kunmap_atomic(kaddr1);
2696}
2697
2698/**
2699 * restore_highmem - Put highmem image pages into their original locations.
2700 *
2701 * For each highmem page that was in use before hibernation and is included in
2702 * the image, and also has been allocated by the "restore" kernel, swap its
2703 * current contents with the previous (ie. "before hibernation") ones.
2704 *
2705 * If the restore eventually fails, we can call this function once again and
2706 * restore the highmem state as seen by the restore kernel.
2707 */
2708int restore_highmem(void)
2709{
2710 struct highmem_pbe *pbe = highmem_pblist;
2711 void *buf;
2712
2713 if (!pbe)
2714 return 0;
2715
2716 buf = get_image_page(GFP_ATOMIC, PG_SAFE);
2717 if (!buf)
2718 return -ENOMEM;
2719
2720 while (pbe) {
2721 swap_two_pages_data(pbe->copy_page, pbe->orig_page, buf);
2722 pbe = pbe->next;
2723 }
2724 free_image_page(buf, PG_UNSAFE_CLEAR);
2725 return 0;
2726}
2727#endif /* CONFIG_HIGHMEM */