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