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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/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)
44 : : static bool hibernate_restore_protection;
45 : : static bool hibernate_restore_protection_active;
46 : :
47 : 0 : void enable_restore_image_protection(void)
48 : : {
49 : 0 : hibernate_restore_protection = true;
50 : 0 : }
51 : :
52 : 0 : static inline void hibernate_restore_protection_begin(void)
53 : : {
54 : 0 : hibernate_restore_protection_active = hibernate_restore_protection;
55 : 0 : }
56 : :
57 : 0 : static inline void hibernate_restore_protection_end(void)
58 : : {
59 : 0 : hibernate_restore_protection_active = false;
60 : : }
61 : :
62 : 0 : static inline void hibernate_restore_protect_page(void *page_address)
63 : : {
64 : 0 : if (hibernate_restore_protection_active)
65 : 0 : set_memory_ro((unsigned long)page_address, 1);
66 : : }
67 : :
68 : 0 : static inline void hibernate_restore_unprotect_page(void *page_address)
69 : : {
70 [ # # ]: 0 : if (hibernate_restore_protection_active)
71 : 0 : set_memory_rw((unsigned long)page_address, 1);
72 : : }
73 : : #else
74 : : static inline void hibernate_restore_protection_begin(void) {}
75 : : static inline void hibernate_restore_protection_end(void) {}
76 : : static inline void hibernate_restore_protect_page(void *page_address) {}
77 : : static inline void hibernate_restore_unprotect_page(void *page_address) {}
78 : : #endif /* CONFIG_STRICT_KERNEL_RWX && CONFIG_ARCH_HAS_SET_MEMORY */
79 : :
80 : : static int swsusp_page_is_free(struct page *);
81 : : static void swsusp_set_page_forbidden(struct page *);
82 : : static 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 : : */
89 : : unsigned long reserved_size;
90 : :
91 : 13 : void __init hibernate_reserved_size_init(void)
92 : : {
93 : 13 : reserved_size = SPARE_PAGES * PAGE_SIZE;
94 : 13 : }
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 : : */
102 : : unsigned long image_size;
103 : :
104 : 13 : void __init hibernate_image_size_init(void)
105 : : {
106 : 13 : image_size = ((totalram_pages() * 2) / 5) * PAGE_SIZE;
107 : 13 : }
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 : : */
115 : : struct 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 : :
121 : : struct 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 : : */
131 : : static struct linked_page *safe_pages_list;
132 : :
133 : : /* Pointer to an auxiliary buffer (1 page) */
134 : : static 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 : :
141 : : static 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 : : */
156 : 0 : static void *get_image_page(gfp_t gfp_mask, int safe_needed)
157 : : {
158 : 0 : void *res;
159 : :
160 : 0 : res = (void *)get_zeroed_page(gfp_mask);
161 [ # # ]: 0 : if (safe_needed)
162 [ # # # # : 0 : while (res && swsusp_page_is_free(virt_to_page(res))) {
# # ]
163 : : /* The page is unsafe, mark it for swsusp_free() */
164 [ # # ]: 0 : swsusp_set_page_forbidden(virt_to_page(res));
165 : 0 : allocated_unsafe_pages++;
166 : 0 : res = (void *)get_zeroed_page(gfp_mask);
167 : : }
168 [ # # ]: 0 : if (res) {
169 [ # # ]: 0 : swsusp_set_page_forbidden(virt_to_page(res));
170 [ # # ]: 0 : swsusp_set_page_free(virt_to_page(res));
171 : : }
172 : 0 : return res;
173 : : }
174 : :
175 : 0 : static void *__get_safe_page(gfp_t gfp_mask)
176 : : {
177 [ # # ]: 0 : if (safe_pages_list) {
178 : 0 : void *ret = safe_pages_list;
179 : :
180 : 0 : safe_pages_list = safe_pages_list->next;
181 : 0 : memset(ret, 0, PAGE_SIZE);
182 : 0 : return ret;
183 : : }
184 : 0 : return get_image_page(gfp_mask, PG_SAFE);
185 : : }
186 : :
187 : 0 : unsigned long get_safe_page(gfp_t gfp_mask)
188 : : {
189 : 0 : return (unsigned long)__get_safe_page(gfp_mask);
190 : : }
191 : :
192 : 0 : static struct page *alloc_image_page(gfp_t gfp_mask)
193 : : {
194 : 0 : struct page *page;
195 : :
196 : 0 : page = alloc_page(gfp_mask);
197 [ # # ]: 0 : if (page) {
198 : 0 : swsusp_set_page_forbidden(page);
199 : 0 : swsusp_set_page_free(page);
200 : : }
201 : 0 : return page;
202 : : }
203 : :
204 : 0 : static void recycle_safe_page(void *page_address)
205 : : {
206 : 0 : struct linked_page *lp = page_address;
207 : :
208 : 0 : lp->next = safe_pages_list;
209 : 0 : safe_pages_list = lp;
210 : 0 : }
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 : : */
220 : 0 : static inline void free_image_page(void *addr, int clear_nosave_free)
221 : : {
222 : 0 : struct page *page;
223 : :
224 [ # # ]: 0 : BUG_ON(!virt_addr_valid(addr));
225 : :
226 [ # # ]: 0 : page = virt_to_page(addr);
227 : :
228 : 0 : swsusp_unset_page_forbidden(page);
229 [ # # ]: 0 : if (clear_nosave_free)
230 : 0 : swsusp_unset_page_free(page);
231 : :
232 : 0 : __free_page(page);
233 : 0 : }
234 : :
235 : 0 : static inline void free_list_of_pages(struct linked_page *list,
236 : : int clear_page_nosave)
237 : : {
238 [ # # ]: 0 : while (list) {
239 : 0 : struct linked_page *lp = list->next;
240 : :
241 : 0 : free_image_page(list, clear_page_nosave);
242 : 0 : 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 : : */
258 : : struct 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 : :
266 : 0 : static void chain_init(struct chain_allocator *ca, gfp_t gfp_mask,
267 : : int safe_needed)
268 : : {
269 : 0 : ca->chain = NULL;
270 : 0 : ca->used_space = LINKED_PAGE_DATA_SIZE;
271 : 0 : ca->gfp_mask = gfp_mask;
272 : 0 : ca->safe_needed = safe_needed;
273 : : }
274 : :
275 : 0 : static void *chain_alloc(struct chain_allocator *ca, unsigned int size)
276 : : {
277 : 0 : void *ret;
278 : :
279 [ # # ]: 0 : if (LINKED_PAGE_DATA_SIZE - ca->used_space < size) {
280 : 0 : struct linked_page *lp;
281 : :
282 [ # # ]: 0 : lp = ca->safe_needed ? __get_safe_page(ca->gfp_mask) :
283 : 0 : get_image_page(ca->gfp_mask, PG_ANY);
284 [ # # ]: 0 : if (!lp)
285 : : return NULL;
286 : :
287 : 0 : lp->next = ca->chain;
288 : 0 : ca->chain = lp;
289 : 0 : ca->used_space = 0;
290 : : }
291 : 0 : ret = ca->chain->data + ca->used_space;
292 : 0 : ca->used_space += size;
293 : 0 : 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 : : */
348 : : struct 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 : : */
357 : : struct 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 : :
370 : : struct 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 : :
377 : : struct 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 : : */
402 : 0 : static 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 : 0 : struct rtree_node *node;
407 : :
408 : 0 : node = chain_alloc(ca, sizeof(struct rtree_node));
409 [ # # ]: 0 : if (!node)
410 : : return NULL;
411 : :
412 : 0 : node->data = get_image_page(gfp_mask, safe_needed);
413 [ # # ]: 0 : if (!node->data)
414 : : return NULL;
415 : :
416 : 0 : list_add_tail(&node->list, list);
417 : :
418 : 0 : 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 : : */
428 : 0 : static int add_rtree_block(struct mem_zone_bm_rtree *zone, gfp_t gfp_mask,
429 : : int safe_needed, struct chain_allocator *ca)
430 : : {
431 : 0 : struct rtree_node *node, *block, **dst;
432 : 0 : unsigned int levels_needed, block_nr;
433 : 0 : int i;
434 : :
435 : 0 : block_nr = zone->blocks;
436 : 0 : levels_needed = 0;
437 : :
438 : : /* How many levels do we need for this block nr? */
439 [ # # ]: 0 : while (block_nr) {
440 : 0 : levels_needed += 1;
441 : 0 : block_nr >>= BM_RTREE_LEVEL_SHIFT;
442 : : }
443 : :
444 : : /* Make sure the rtree has enough levels */
445 [ # # ]: 0 : for (i = zone->levels; i < levels_needed; i++) {
446 : 0 : node = alloc_rtree_node(gfp_mask, safe_needed, ca,
447 : : &zone->nodes);
448 [ # # ]: 0 : if (!node)
449 : : return -ENOMEM;
450 : :
451 : 0 : node->data[0] = (unsigned long)zone->rtree;
452 : 0 : zone->rtree = node;
453 : 0 : zone->levels += 1;
454 : : }
455 : :
456 : : /* Allocate new block */
457 : 0 : block = alloc_rtree_node(gfp_mask, safe_needed, ca, &zone->leaves);
458 [ # # ]: 0 : if (!block)
459 : : return -ENOMEM;
460 : :
461 : : /* Now walk the rtree to insert the block */
462 : 0 : node = zone->rtree;
463 : 0 : dst = &zone->rtree;
464 : 0 : block_nr = zone->blocks;
465 [ # # ]: 0 : for (i = zone->levels; i > 0; i--) {
466 : 0 : int index;
467 : :
468 [ # # ]: 0 : if (!node) {
469 : 0 : node = alloc_rtree_node(gfp_mask, safe_needed, ca,
470 : : &zone->nodes);
471 [ # # ]: 0 : if (!node)
472 : : return -ENOMEM;
473 : 0 : *dst = node;
474 : : }
475 : :
476 : 0 : index = block_nr >> ((i - 1) * BM_RTREE_LEVEL_SHIFT);
477 : 0 : index &= BM_RTREE_LEVEL_MASK;
478 : 0 : dst = (struct rtree_node **)&((*dst)->data[index]);
479 : 0 : node = *dst;
480 : : }
481 : :
482 : 0 : zone->blocks += 1;
483 : 0 : *dst = block;
484 : :
485 : 0 : return 0;
486 : : }
487 : :
488 : : static 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 : : */
498 : 0 : static 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 : 0 : struct mem_zone_bm_rtree *zone;
505 : 0 : unsigned int i, nr_blocks;
506 : 0 : unsigned long pages;
507 : :
508 : 0 : pages = end - start;
509 : 0 : zone = chain_alloc(ca, sizeof(struct mem_zone_bm_rtree));
510 [ # # ]: 0 : if (!zone)
511 : : return NULL;
512 : :
513 : 0 : INIT_LIST_HEAD(&zone->nodes);
514 : 0 : INIT_LIST_HEAD(&zone->leaves);
515 : 0 : zone->start_pfn = start;
516 : 0 : zone->end_pfn = end;
517 : 0 : nr_blocks = DIV_ROUND_UP(pages, BM_BITS_PER_BLOCK);
518 : :
519 [ # # ]: 0 : for (i = 0; i < nr_blocks; i++) {
520 [ # # ]: 0 : if (add_rtree_block(zone, gfp_mask, safe_needed, ca)) {
521 : 0 : free_zone_bm_rtree(zone, PG_UNSAFE_CLEAR);
522 : 0 : 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 : : */
536 : 0 : static void free_zone_bm_rtree(struct mem_zone_bm_rtree *zone,
537 : : int clear_nosave_free)
538 : : {
539 : 0 : struct rtree_node *node;
540 : :
541 [ # # ]: 0 : list_for_each_entry(node, &zone->nodes, list)
542 : 0 : free_image_page(node->data, clear_nosave_free);
543 : :
544 [ # # ]: 0 : list_for_each_entry(node, &zone->leaves, list)
545 : 0 : free_image_page(node->data, clear_nosave_free);
546 : 0 : }
547 : :
548 : 0 : static void memory_bm_position_reset(struct memory_bitmap *bm)
549 : : {
550 : 0 : bm->cur.zone = list_entry(bm->zones.next, struct mem_zone_bm_rtree,
551 : : list);
552 : 0 : bm->cur.node = list_entry(bm->cur.zone->leaves.next,
553 : : struct rtree_node, list);
554 : 0 : bm->cur.node_pfn = 0;
555 : 0 : bm->cur.node_bit = 0;
556 : 0 : }
557 : :
558 : : static void memory_bm_free(struct memory_bitmap *bm, int clear_nosave_free);
559 : :
560 : : struct 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 : : */
570 : 0 : static void free_mem_extents(struct list_head *list)
571 : : {
572 : 0 : struct mem_extent *ext, *aux;
573 : :
574 [ # # ]: 0 : list_for_each_entry_safe(ext, aux, list, hook) {
575 : 0 : list_del(&ext->hook);
576 : 0 : kfree(ext);
577 : : }
578 : 0 : }
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 : : */
587 : 0 : static int create_mem_extents(struct list_head *list, gfp_t gfp_mask)
588 : : {
589 : 0 : struct zone *zone;
590 : :
591 : 0 : INIT_LIST_HEAD(list);
592 : :
593 [ # # # # ]: 0 : for_each_populated_zone(zone) {
594 : 0 : unsigned long zone_start, zone_end;
595 : 0 : struct mem_extent *ext, *cur, *aux;
596 : :
597 : 0 : zone_start = zone->zone_start_pfn;
598 : 0 : zone_end = zone_end_pfn(zone);
599 : :
600 [ # # ]: 0 : list_for_each_entry(ext, list, hook)
601 [ # # ]: 0 : if (zone_start <= ext->end)
602 : : break;
603 : :
604 [ # # # # ]: 0 : if (&ext->hook == list || zone_end < ext->start) {
605 : : /* New extent is necessary */
606 : 0 : struct mem_extent *new_ext;
607 : :
608 : 0 : new_ext = kzalloc(sizeof(struct mem_extent), gfp_mask);
609 [ # # ]: 0 : if (!new_ext) {
610 : 0 : free_mem_extents(list);
611 : 0 : return -ENOMEM;
612 : : }
613 : 0 : new_ext->start = zone_start;
614 : 0 : new_ext->end = zone_end;
615 : 0 : list_add_tail(&new_ext->hook, &ext->hook);
616 : 0 : continue;
617 : : }
618 : :
619 : : /* Merge this zone's range of PFNs with the existing one */
620 [ # # ]: 0 : if (zone_start < ext->start)
621 : 0 : ext->start = zone_start;
622 [ # # ]: 0 : if (zone_end > ext->end)
623 : 0 : ext->end = zone_end;
624 : :
625 : : /* More merging may be possible */
626 : 0 : cur = ext;
627 [ # # ]: 0 : list_for_each_entry_safe_continue(cur, aux, list, hook) {
628 [ # # ]: 0 : if (zone_end < cur->start)
629 : : break;
630 [ # # ]: 0 : if (zone_end < cur->end)
631 : 0 : ext->end = cur->end;
632 : 0 : list_del(&cur->hook);
633 : 0 : kfree(cur);
634 : : }
635 : : }
636 : :
637 : : return 0;
638 : : }
639 : :
640 : : /**
641 : : * memory_bm_create - Allocate memory for a memory bitmap.
642 : : */
643 : 0 : static int memory_bm_create(struct memory_bitmap *bm, gfp_t gfp_mask,
644 : : int safe_needed)
645 : : {
646 : 0 : struct chain_allocator ca;
647 : 0 : struct list_head mem_extents;
648 : 0 : struct mem_extent *ext;
649 : 0 : int error;
650 : :
651 : 0 : chain_init(&ca, gfp_mask, safe_needed);
652 : 0 : INIT_LIST_HEAD(&bm->zones);
653 : :
654 : 0 : error = create_mem_extents(&mem_extents, gfp_mask);
655 [ # # ]: 0 : if (error)
656 : : return error;
657 : :
658 [ # # ]: 0 : list_for_each_entry(ext, &mem_extents, hook) {
659 : 0 : struct mem_zone_bm_rtree *zone;
660 : :
661 : 0 : zone = create_zone_bm_rtree(gfp_mask, safe_needed, &ca,
662 : : ext->start, ext->end);
663 [ # # ]: 0 : if (!zone) {
664 : 0 : error = -ENOMEM;
665 : 0 : goto Error;
666 : : }
667 : 0 : list_add_tail(&zone->list, &bm->zones);
668 : : }
669 : :
670 : 0 : bm->p_list = ca.chain;
671 : 0 : memory_bm_position_reset(bm);
672 : 0 : Exit:
673 : 0 : free_mem_extents(&mem_extents);
674 : 0 : return error;
675 : :
676 : : Error:
677 : 0 : bm->p_list = ca.chain;
678 : 0 : memory_bm_free(bm, PG_UNSAFE_CLEAR);
679 : 0 : goto Exit;
680 : : }
681 : :
682 : : /**
683 : : * memory_bm_free - Free memory occupied by the memory bitmap.
684 : : * @bm: Memory bitmap.
685 : : */
686 : 0 : static void memory_bm_free(struct memory_bitmap *bm, int clear_nosave_free)
687 : : {
688 : 0 : struct mem_zone_bm_rtree *zone;
689 : :
690 [ # # ]: 0 : list_for_each_entry(zone, &bm->zones, list)
691 : 0 : free_zone_bm_rtree(zone, clear_nosave_free);
692 : :
693 : 0 : free_list_of_pages(bm->p_list, clear_nosave_free);
694 : :
695 : 0 : INIT_LIST_HEAD(&bm->zones);
696 : 0 : }
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 : : */
707 : 0 : static int memory_bm_find_bit(struct memory_bitmap *bm, unsigned long pfn,
708 : : void **addr, unsigned int *bit_nr)
709 : : {
710 : 0 : struct mem_zone_bm_rtree *curr, *zone;
711 : 0 : struct rtree_node *node;
712 : 0 : int i, block_nr;
713 : :
714 : 0 : zone = bm->cur.zone;
715 : :
716 [ # # # # ]: 0 : if (pfn >= zone->start_pfn && pfn < zone->end_pfn)
717 : 0 : goto zone_found;
718 : :
719 : 0 : zone = NULL;
720 : :
721 : : /* Find the right zone */
722 [ # # ]: 0 : list_for_each_entry(curr, &bm->zones, list) {
723 [ # # # # ]: 0 : if (pfn >= curr->start_pfn && pfn < curr->end_pfn) {
724 : : zone = curr;
725 : : break;
726 : : }
727 : : }
728 : :
729 [ # # ]: 0 : if (!zone)
730 : : return -EFAULT;
731 : :
732 : 0 : zone_found:
733 : : /*
734 : : * We have found the zone. Now walk the radix tree to find the leaf node
735 : : * for our PFN.
736 : : */
737 : :
738 : : /*
739 : : * If the zone we wish to scan is the the current zone and the
740 : : * pfn falls into the current node then we do not need to walk
741 : : * the tree.
742 : : */
743 : 0 : node = bm->cur.node;
744 [ # # ]: 0 : if (zone == bm->cur.zone &&
745 [ # # ]: 0 : ((pfn - zone->start_pfn) & ~BM_BLOCK_MASK) == bm->cur.node_pfn)
746 : 0 : goto node_found;
747 : :
748 : 0 : node = zone->rtree;
749 : 0 : block_nr = (pfn - zone->start_pfn) >> BM_BLOCK_SHIFT;
750 : :
751 [ # # ]: 0 : for (i = zone->levels; i > 0; i--) {
752 : 0 : int index;
753 : :
754 : 0 : index = block_nr >> ((i - 1) * BM_RTREE_LEVEL_SHIFT);
755 : 0 : index &= BM_RTREE_LEVEL_MASK;
756 [ # # ]: 0 : BUG_ON(node->data[index] == 0);
757 : 0 : node = (struct rtree_node *)node->data[index];
758 : : }
759 : :
760 : 0 : node_found:
761 : : /* Update last position */
762 : 0 : bm->cur.zone = zone;
763 : 0 : bm->cur.node = node;
764 : 0 : bm->cur.node_pfn = (pfn - zone->start_pfn) & ~BM_BLOCK_MASK;
765 : :
766 : : /* Set return values */
767 : 0 : *addr = node->data;
768 : 0 : *bit_nr = (pfn - zone->start_pfn) & BM_BLOCK_MASK;
769 : :
770 : 0 : return 0;
771 : : }
772 : :
773 : 0 : static void memory_bm_set_bit(struct memory_bitmap *bm, unsigned long pfn)
774 : : {
775 : 0 : void *addr;
776 : 0 : unsigned int bit;
777 : 0 : int error;
778 : :
779 : 0 : error = memory_bm_find_bit(bm, pfn, &addr, &bit);
780 [ # # ]: 0 : BUG_ON(error);
781 : 0 : set_bit(bit, addr);
782 : 0 : }
783 : :
784 : 0 : static int mem_bm_set_bit_check(struct memory_bitmap *bm, unsigned long pfn)
785 : : {
786 : 0 : void *addr;
787 : 0 : unsigned int bit;
788 : 0 : int error;
789 : :
790 : 0 : error = memory_bm_find_bit(bm, pfn, &addr, &bit);
791 [ # # ]: 0 : if (!error)
792 : 0 : set_bit(bit, addr);
793 : :
794 : 0 : return error;
795 : : }
796 : :
797 : 0 : static void memory_bm_clear_bit(struct memory_bitmap *bm, unsigned long pfn)
798 : : {
799 : 0 : void *addr;
800 : 0 : unsigned int bit;
801 : 0 : int error;
802 : :
803 : 0 : error = memory_bm_find_bit(bm, pfn, &addr, &bit);
804 [ # # ]: 0 : BUG_ON(error);
805 : 0 : clear_bit(bit, addr);
806 : 0 : }
807 : :
808 : 0 : static void memory_bm_clear_current(struct memory_bitmap *bm)
809 : : {
810 : 0 : int bit;
811 : :
812 : 0 : bit = max(bm->cur.node_bit - 1, 0);
813 : 0 : clear_bit(bit, bm->cur.node->data);
814 : : }
815 : :
816 : 0 : static int memory_bm_test_bit(struct memory_bitmap *bm, unsigned long pfn)
817 : : {
818 : 0 : void *addr;
819 : 0 : unsigned int bit;
820 : 0 : int error;
821 : :
822 : 0 : error = memory_bm_find_bit(bm, pfn, &addr, &bit);
823 [ # # ]: 0 : BUG_ON(error);
824 [ # # ]: 0 : return test_bit(bit, addr);
825 : : }
826 : :
827 : 0 : static bool memory_bm_pfn_present(struct memory_bitmap *bm, unsigned long pfn)
828 : : {
829 : 0 : void *addr;
830 : 0 : unsigned int bit;
831 : :
832 : 0 : return !memory_bm_find_bit(bm, pfn, &addr, &bit);
833 : : }
834 : :
835 : : /*
836 : : * rtree_next_node - Jump to the next leaf node.
837 : : *
838 : : * Set the position to the beginning of the next node in the
839 : : * memory bitmap. This is either the next node in the current
840 : : * zone's radix tree or the first node in the radix tree of the
841 : : * next zone.
842 : : *
843 : : * Return true if there is a next node, false otherwise.
844 : : */
845 : 0 : static bool rtree_next_node(struct memory_bitmap *bm)
846 : : {
847 : 0 : if (!list_is_last(&bm->cur.node->list, &bm->cur.zone->leaves)) {
848 : 0 : bm->cur.node = list_entry(bm->cur.node->list.next,
849 : : struct rtree_node, list);
850 : 0 : bm->cur.node_pfn += BM_BITS_PER_BLOCK;
851 : 0 : bm->cur.node_bit = 0;
852 : 0 : touch_softlockup_watchdog();
853 : 0 : return true;
854 : : }
855 : :
856 : : /* No more nodes, goto next zone */
857 [ # # ]: 0 : if (!list_is_last(&bm->cur.zone->list, &bm->zones)) {
858 : 0 : bm->cur.zone = list_entry(bm->cur.zone->list.next,
859 : : struct mem_zone_bm_rtree, list);
860 : 0 : bm->cur.node = list_entry(bm->cur.zone->leaves.next,
861 : : struct rtree_node, list);
862 : 0 : bm->cur.node_pfn = 0;
863 : 0 : bm->cur.node_bit = 0;
864 : 0 : return true;
865 : : }
866 : :
867 : : /* No more zones */
868 : : return false;
869 : : }
870 : :
871 : : /**
872 : : * memory_bm_rtree_next_pfn - Find the next set bit in a memory bitmap.
873 : : * @bm: Memory bitmap.
874 : : *
875 : : * Starting from the last returned position this function searches for the next
876 : : * set bit in @bm and returns the PFN represented by it. If no more bits are
877 : : * set, BM_END_OF_MAP is returned.
878 : : *
879 : : * It is required to run memory_bm_position_reset() before the first call to
880 : : * this function for the given memory bitmap.
881 : : */
882 : 0 : static unsigned long memory_bm_next_pfn(struct memory_bitmap *bm)
883 : : {
884 : 0 : unsigned long bits, pfn, pages;
885 : 0 : int bit;
886 : :
887 : 0 : do {
888 : 0 : pages = bm->cur.zone->end_pfn - bm->cur.zone->start_pfn;
889 : 0 : bits = min(pages - bm->cur.node_pfn, BM_BITS_PER_BLOCK);
890 : 0 : bit = find_next_bit(bm->cur.node->data, bits,
891 : 0 : bm->cur.node_bit);
892 [ # # ]: 0 : if (bit < bits) {
893 : 0 : pfn = bm->cur.zone->start_pfn + bm->cur.node_pfn + bit;
894 : 0 : bm->cur.node_bit = bit + 1;
895 : 0 : return pfn;
896 : : }
897 [ # # ]: 0 : } while (rtree_next_node(bm));
898 : :
899 : : return BM_END_OF_MAP;
900 : : }
901 : :
902 : : /*
903 : : * This structure represents a range of page frames the contents of which
904 : : * should not be saved during hibernation.
905 : : */
906 : : struct nosave_region {
907 : : struct list_head list;
908 : : unsigned long start_pfn;
909 : : unsigned long end_pfn;
910 : : };
911 : :
912 : : static LIST_HEAD(nosave_regions);
913 : :
914 : 0 : static void recycle_zone_bm_rtree(struct mem_zone_bm_rtree *zone)
915 : : {
916 : 0 : struct rtree_node *node;
917 : :
918 [ # # ]: 0 : list_for_each_entry(node, &zone->nodes, list)
919 : 0 : recycle_safe_page(node->data);
920 : :
921 [ # # ]: 0 : list_for_each_entry(node, &zone->leaves, list)
922 : 0 : recycle_safe_page(node->data);
923 : : }
924 : :
925 : 0 : static void memory_bm_recycle(struct memory_bitmap *bm)
926 : : {
927 : 0 : struct mem_zone_bm_rtree *zone;
928 : 0 : struct linked_page *p_list;
929 : :
930 [ # # ]: 0 : list_for_each_entry(zone, &bm->zones, list)
931 : 0 : recycle_zone_bm_rtree(zone);
932 : :
933 : 0 : p_list = bm->p_list;
934 [ # # ]: 0 : while (p_list) {
935 : 0 : struct linked_page *lp = p_list;
936 : :
937 : 0 : p_list = lp->next;
938 : 0 : recycle_safe_page(lp);
939 : : }
940 : 0 : }
941 : :
942 : : /**
943 : : * register_nosave_region - Register a region of unsaveable memory.
944 : : *
945 : : * Register a range of page frames the contents of which should not be saved
946 : : * during hibernation (to be used in the early initialization code).
947 : : */
948 : 65 : void __init __register_nosave_region(unsigned long start_pfn,
949 : : unsigned long end_pfn, int use_kmalloc)
950 : : {
951 : 65 : struct nosave_region *region;
952 : :
953 [ + + ]: 65 : if (start_pfn >= end_pfn)
954 : : return;
955 : :
956 [ + + ]: 52 : if (!list_empty(&nosave_regions)) {
957 : : /* Try to extend the previous region (they should be sorted) */
958 : 39 : region = list_entry(nosave_regions.prev,
959 : : struct nosave_region, list);
960 [ + + ]: 39 : if (region->end_pfn == start_pfn) {
961 : 26 : region->end_pfn = end_pfn;
962 : 26 : goto Report;
963 : : }
964 : : }
965 [ - + ]: 26 : if (use_kmalloc) {
966 : : /* During init, this shouldn't fail */
967 : 0 : region = kmalloc(sizeof(struct nosave_region), GFP_KERNEL);
968 [ # # ]: 0 : BUG_ON(!region);
969 : : } else {
970 : : /* This allocation cannot fail */
971 : 26 : region = memblock_alloc(sizeof(struct nosave_region),
972 : : SMP_CACHE_BYTES);
973 [ - + ]: 26 : if (!region)
974 : 0 : panic("%s: Failed to allocate %zu bytes\n", __func__,
975 : : sizeof(struct nosave_region));
976 : : }
977 : 26 : region->start_pfn = start_pfn;
978 : 26 : region->end_pfn = end_pfn;
979 : 26 : list_add_tail(®ion->list, &nosave_regions);
980 : 52 : Report:
981 : 52 : pr_info("Registered nosave memory: [mem %#010llx-%#010llx]\n",
982 : : (unsigned long long) start_pfn << PAGE_SHIFT,
983 : : ((unsigned long long) end_pfn << PAGE_SHIFT) - 1);
984 : : }
985 : :
986 : : /*
987 : : * Set bits in this map correspond to the page frames the contents of which
988 : : * should not be saved during the suspend.
989 : : */
990 : : static struct memory_bitmap *forbidden_pages_map;
991 : :
992 : : /* Set bits in this map correspond to free page frames. */
993 : : static struct memory_bitmap *free_pages_map;
994 : :
995 : : /*
996 : : * Each page frame allocated for creating the image is marked by setting the
997 : : * corresponding bits in forbidden_pages_map and free_pages_map simultaneously
998 : : */
999 : :
1000 : 0 : void swsusp_set_page_free(struct page *page)
1001 : : {
1002 [ # # # # : 0 : if (free_pages_map)
# # ]
1003 : 0 : memory_bm_set_bit(free_pages_map, page_to_pfn(page));
1004 : 0 : }
1005 : :
1006 : 0 : static int swsusp_page_is_free(struct page *page)
1007 : : {
1008 : 0 : return free_pages_map ?
1009 [ # # # # : 0 : memory_bm_test_bit(free_pages_map, page_to_pfn(page)) : 0;
# # ]
1010 : : }
1011 : :
1012 : 0 : void swsusp_unset_page_free(struct page *page)
1013 : : {
1014 [ # # # # ]: 0 : if (free_pages_map)
1015 : 0 : memory_bm_clear_bit(free_pages_map, page_to_pfn(page));
1016 : 0 : }
1017 : :
1018 : 0 : static void swsusp_set_page_forbidden(struct page *page)
1019 : : {
1020 [ # # # # : 0 : if (forbidden_pages_map)
# # ]
1021 : 0 : memory_bm_set_bit(forbidden_pages_map, page_to_pfn(page));
1022 : : }
1023 : :
1024 : 0 : int swsusp_page_is_forbidden(struct page *page)
1025 : : {
1026 : 0 : return forbidden_pages_map ?
1027 [ # # ]: 0 : memory_bm_test_bit(forbidden_pages_map, page_to_pfn(page)) : 0;
1028 : : }
1029 : :
1030 : 0 : static void swsusp_unset_page_forbidden(struct page *page)
1031 : : {
1032 [ # # ]: 0 : if (forbidden_pages_map)
1033 : 0 : memory_bm_clear_bit(forbidden_pages_map, page_to_pfn(page));
1034 : : }
1035 : :
1036 : : /**
1037 : : * mark_nosave_pages - Mark pages that should not be saved.
1038 : : * @bm: Memory bitmap.
1039 : : *
1040 : : * Set the bits in @bm that correspond to the page frames the contents of which
1041 : : * should not be saved.
1042 : : */
1043 : 0 : static void mark_nosave_pages(struct memory_bitmap *bm)
1044 : : {
1045 : 0 : struct nosave_region *region;
1046 : :
1047 [ # # ]: 0 : if (list_empty(&nosave_regions))
1048 : : return;
1049 : :
1050 [ # # ]: 0 : list_for_each_entry(region, &nosave_regions, list) {
1051 : 0 : unsigned long pfn;
1052 : :
1053 : 0 : pr_debug("Marking nosave pages: [mem %#010llx-%#010llx]\n",
1054 : : (unsigned long long) region->start_pfn << PAGE_SHIFT,
1055 : : ((unsigned long long) region->end_pfn << PAGE_SHIFT)
1056 : : - 1);
1057 : :
1058 [ # # ]: 0 : for (pfn = region->start_pfn; pfn < region->end_pfn; pfn++)
1059 [ # # ]: 0 : if (pfn_valid(pfn)) {
1060 : : /*
1061 : : * It is safe to ignore the result of
1062 : : * mem_bm_set_bit_check() here, since we won't
1063 : : * touch the PFNs for which the error is
1064 : : * returned anyway.
1065 : : */
1066 : 0 : mem_bm_set_bit_check(bm, pfn);
1067 : : }
1068 : : }
1069 : : }
1070 : :
1071 : : /**
1072 : : * create_basic_memory_bitmaps - Create bitmaps to hold basic page information.
1073 : : *
1074 : : * Create bitmaps needed for marking page frames that should not be saved and
1075 : : * free page frames. The forbidden_pages_map and free_pages_map pointers are
1076 : : * only modified if everything goes well, because we don't want the bits to be
1077 : : * touched before both bitmaps are set up.
1078 : : */
1079 : 0 : int create_basic_memory_bitmaps(void)
1080 : : {
1081 : 0 : struct memory_bitmap *bm1, *bm2;
1082 : 0 : int error = 0;
1083 : :
1084 [ # # # # ]: 0 : if (forbidden_pages_map && free_pages_map)
1085 : : return 0;
1086 : : else
1087 [ # # # # ]: 0 : BUG_ON(forbidden_pages_map || free_pages_map);
1088 : :
1089 : 0 : bm1 = kzalloc(sizeof(struct memory_bitmap), GFP_KERNEL);
1090 [ # # ]: 0 : if (!bm1)
1091 : : return -ENOMEM;
1092 : :
1093 : 0 : error = memory_bm_create(bm1, GFP_KERNEL, PG_ANY);
1094 [ # # ]: 0 : if (error)
1095 : 0 : goto Free_first_object;
1096 : :
1097 : 0 : bm2 = kzalloc(sizeof(struct memory_bitmap), GFP_KERNEL);
1098 [ # # ]: 0 : if (!bm2)
1099 : 0 : goto Free_first_bitmap;
1100 : :
1101 : 0 : error = memory_bm_create(bm2, GFP_KERNEL, PG_ANY);
1102 [ # # ]: 0 : if (error)
1103 : 0 : goto Free_second_object;
1104 : :
1105 : 0 : forbidden_pages_map = bm1;
1106 : 0 : free_pages_map = bm2;
1107 : 0 : mark_nosave_pages(forbidden_pages_map);
1108 : :
1109 : 0 : pr_debug("Basic memory bitmaps created\n");
1110 : :
1111 : 0 : return 0;
1112 : :
1113 : : Free_second_object:
1114 : 0 : kfree(bm2);
1115 : 0 : Free_first_bitmap:
1116 : 0 : memory_bm_free(bm1, PG_UNSAFE_CLEAR);
1117 : 0 : Free_first_object:
1118 : 0 : kfree(bm1);
1119 : 0 : return -ENOMEM;
1120 : : }
1121 : :
1122 : : /**
1123 : : * free_basic_memory_bitmaps - Free memory bitmaps holding basic information.
1124 : : *
1125 : : * Free memory bitmaps allocated by create_basic_memory_bitmaps(). The
1126 : : * auxiliary pointers are necessary so that the bitmaps themselves are not
1127 : : * referred to while they are being freed.
1128 : : */
1129 : 0 : void free_basic_memory_bitmaps(void)
1130 : : {
1131 : 0 : struct memory_bitmap *bm1, *bm2;
1132 : :
1133 [ # # # # : 0 : if (WARN_ON(!(forbidden_pages_map && free_pages_map)))
# # # # ]
1134 : : return;
1135 : :
1136 : 0 : bm1 = forbidden_pages_map;
1137 : 0 : bm2 = free_pages_map;
1138 : 0 : forbidden_pages_map = NULL;
1139 : 0 : free_pages_map = NULL;
1140 : 0 : memory_bm_free(bm1, PG_UNSAFE_CLEAR);
1141 : 0 : kfree(bm1);
1142 : 0 : memory_bm_free(bm2, PG_UNSAFE_CLEAR);
1143 : 0 : kfree(bm2);
1144 : :
1145 : 0 : pr_debug("Basic memory bitmaps freed\n");
1146 : : }
1147 : :
1148 : 0 : void clear_free_pages(void)
1149 : : {
1150 : 0 : struct memory_bitmap *bm = free_pages_map;
1151 : 0 : unsigned long pfn;
1152 : :
1153 [ # # # # ]: 0 : if (WARN_ON(!(free_pages_map)))
1154 : : return;
1155 : :
1156 [ # # # # ]: 0 : if (IS_ENABLED(CONFIG_PAGE_POISONING_ZERO) || want_init_on_free()) {
1157 : 0 : memory_bm_position_reset(bm);
1158 : 0 : pfn = memory_bm_next_pfn(bm);
1159 [ # # ]: 0 : while (pfn != BM_END_OF_MAP) {
1160 [ # # ]: 0 : if (pfn_valid(pfn))
1161 : 0 : clear_highpage(pfn_to_page(pfn));
1162 : :
1163 : 0 : pfn = memory_bm_next_pfn(bm);
1164 : : }
1165 : 0 : memory_bm_position_reset(bm);
1166 : 0 : pr_info("free pages cleared after restore\n");
1167 : : }
1168 : : }
1169 : :
1170 : : /**
1171 : : * snapshot_additional_pages - Estimate the number of extra pages needed.
1172 : : * @zone: Memory zone to carry out the computation for.
1173 : : *
1174 : : * Estimate the number of additional pages needed for setting up a hibernation
1175 : : * image data structures for @zone (usually, the returned value is greater than
1176 : : * the exact number).
1177 : : */
1178 : 0 : unsigned int snapshot_additional_pages(struct zone *zone)
1179 : : {
1180 : 0 : unsigned int rtree, nodes;
1181 : :
1182 : 0 : rtree = nodes = DIV_ROUND_UP(zone->spanned_pages, BM_BITS_PER_BLOCK);
1183 : 0 : rtree += DIV_ROUND_UP(rtree * sizeof(struct rtree_node),
1184 : : LINKED_PAGE_DATA_SIZE);
1185 [ # # # # ]: 0 : while (nodes > 1) {
1186 : 0 : nodes = DIV_ROUND_UP(nodes, BM_ENTRIES_PER_LEVEL);
1187 : 0 : rtree += nodes;
1188 : : }
1189 : :
1190 : 0 : return 2 * rtree;
1191 : : }
1192 : :
1193 : : #ifdef CONFIG_HIGHMEM
1194 : : /**
1195 : : * count_free_highmem_pages - Compute the total number of free highmem pages.
1196 : : *
1197 : : * The returned number is system-wide.
1198 : : */
1199 : : static unsigned int count_free_highmem_pages(void)
1200 : : {
1201 : : struct zone *zone;
1202 : : unsigned int cnt = 0;
1203 : :
1204 : : for_each_populated_zone(zone)
1205 : : if (is_highmem(zone))
1206 : : cnt += zone_page_state(zone, NR_FREE_PAGES);
1207 : :
1208 : : return cnt;
1209 : : }
1210 : :
1211 : : /**
1212 : : * saveable_highmem_page - Check if a highmem page is saveable.
1213 : : *
1214 : : * Determine whether a highmem page should be included in a hibernation image.
1215 : : *
1216 : : * We should save the page if it isn't Nosave or NosaveFree, or Reserved,
1217 : : * and it isn't part of a free chunk of pages.
1218 : : */
1219 : : static struct page *saveable_highmem_page(struct zone *zone, unsigned long pfn)
1220 : : {
1221 : : struct page *page;
1222 : :
1223 : : if (!pfn_valid(pfn))
1224 : : return NULL;
1225 : :
1226 : : page = pfn_to_online_page(pfn);
1227 : : if (!page || page_zone(page) != zone)
1228 : : return NULL;
1229 : :
1230 : : BUG_ON(!PageHighMem(page));
1231 : :
1232 : : if (swsusp_page_is_forbidden(page) || swsusp_page_is_free(page))
1233 : : return NULL;
1234 : :
1235 : : if (PageReserved(page) || PageOffline(page))
1236 : : return NULL;
1237 : :
1238 : : if (page_is_guard(page))
1239 : : return NULL;
1240 : :
1241 : : return page;
1242 : : }
1243 : :
1244 : : /**
1245 : : * count_highmem_pages - Compute the total number of saveable highmem pages.
1246 : : */
1247 : : static unsigned int count_highmem_pages(void)
1248 : : {
1249 : : struct zone *zone;
1250 : : unsigned int n = 0;
1251 : :
1252 : : for_each_populated_zone(zone) {
1253 : : unsigned long pfn, max_zone_pfn;
1254 : :
1255 : : if (!is_highmem(zone))
1256 : : continue;
1257 : :
1258 : : mark_free_pages(zone);
1259 : : max_zone_pfn = zone_end_pfn(zone);
1260 : : for (pfn = zone->zone_start_pfn; pfn < max_zone_pfn; pfn++)
1261 : : if (saveable_highmem_page(zone, pfn))
1262 : : n++;
1263 : : }
1264 : : return n;
1265 : : }
1266 : : #else
1267 : : static inline void *saveable_highmem_page(struct zone *z, unsigned long p)
1268 : : {
1269 : : return NULL;
1270 : : }
1271 : : #endif /* CONFIG_HIGHMEM */
1272 : :
1273 : : /**
1274 : : * saveable_page - Check if the given page is saveable.
1275 : : *
1276 : : * Determine whether a non-highmem page should be included in a hibernation
1277 : : * image.
1278 : : *
1279 : : * We should save the page if it isn't Nosave, and is not in the range
1280 : : * of pages statically defined as 'unsaveable', and it isn't part of
1281 : : * a free chunk of pages.
1282 : : */
1283 : 0 : static struct page *saveable_page(struct zone *zone, unsigned long pfn)
1284 : : {
1285 : 0 : struct page *page;
1286 : :
1287 [ # # ]: 0 : if (!pfn_valid(pfn))
1288 : : return NULL;
1289 : :
1290 [ # # ]: 0 : page = pfn_to_online_page(pfn);
1291 [ # # # # ]: 0 : if (!page || page_zone(page) != zone)
1292 : : return NULL;
1293 : :
1294 [ # # ]: 0 : BUG_ON(PageHighMem(page));
1295 : :
1296 [ # # # # : 0 : if (swsusp_page_is_forbidden(page) || swsusp_page_is_free(page))
# # ]
1297 : 0 : return NULL;
1298 : :
1299 [ # # ]: 0 : if (PageOffline(page))
1300 : : return NULL;
1301 : :
1302 [ # # ]: 0 : if (PageReserved(page)
1303 [ # # # # ]: 0 : && (!kernel_page_present(page) || pfn_is_nosave(pfn)))
1304 : 0 : return NULL;
1305 : :
1306 : : if (page_is_guard(page))
1307 : : return NULL;
1308 : :
1309 : : return page;
1310 : : }
1311 : :
1312 : : /**
1313 : : * count_data_pages - Compute the total number of saveable non-highmem pages.
1314 : : */
1315 : 0 : static unsigned int count_data_pages(void)
1316 : : {
1317 : 0 : struct zone *zone;
1318 : 0 : unsigned long pfn, max_zone_pfn;
1319 : 0 : unsigned int n = 0;
1320 : :
1321 [ # # # # ]: 0 : for_each_populated_zone(zone) {
1322 : 0 : if (is_highmem(zone))
1323 : : continue;
1324 : :
1325 : 0 : mark_free_pages(zone);
1326 : 0 : max_zone_pfn = zone_end_pfn(zone);
1327 [ # # ]: 0 : for (pfn = zone->zone_start_pfn; pfn < max_zone_pfn; pfn++)
1328 [ # # ]: 0 : if (saveable_page(zone, pfn))
1329 : 0 : n++;
1330 : : }
1331 : 0 : return n;
1332 : : }
1333 : :
1334 : : /*
1335 : : * This is needed, because copy_page and memcpy are not usable for copying
1336 : : * task structs.
1337 : : */
1338 : 0 : static inline void do_copy_page(long *dst, long *src)
1339 : : {
1340 : : int n;
1341 : :
1342 [ # # # # ]: 0 : for (n = PAGE_SIZE / sizeof(long); n; n--)
1343 : 0 : *dst++ = *src++;
1344 : : }
1345 : :
1346 : : /**
1347 : : * safe_copy_page - Copy a page in a safe way.
1348 : : *
1349 : : * Check if the page we are going to copy is marked as present in the kernel
1350 : : * page tables. This always is the case if CONFIG_DEBUG_PAGEALLOC or
1351 : : * CONFIG_ARCH_HAS_SET_DIRECT_MAP is not set. In that case kernel_page_present()
1352 : : * always returns 'true'.
1353 : : */
1354 : 0 : static void safe_copy_page(void *dst, struct page *s_page)
1355 : : {
1356 [ # # ]: 0 : if (kernel_page_present(s_page)) {
1357 : 0 : do_copy_page(dst, page_address(s_page));
1358 : : } else {
1359 : 0 : kernel_map_pages(s_page, 1, 1);
1360 : 0 : do_copy_page(dst, page_address(s_page));
1361 : 0 : kernel_map_pages(s_page, 1, 0);
1362 : : }
1363 : 0 : }
1364 : :
1365 : : #ifdef CONFIG_HIGHMEM
1366 : : static inline struct page *page_is_saveable(struct zone *zone, unsigned long pfn)
1367 : : {
1368 : : return is_highmem(zone) ?
1369 : : saveable_highmem_page(zone, pfn) : saveable_page(zone, pfn);
1370 : : }
1371 : :
1372 : : static void copy_data_page(unsigned long dst_pfn, unsigned long src_pfn)
1373 : : {
1374 : : struct page *s_page, *d_page;
1375 : : void *src, *dst;
1376 : :
1377 : : s_page = pfn_to_page(src_pfn);
1378 : : d_page = pfn_to_page(dst_pfn);
1379 : : if (PageHighMem(s_page)) {
1380 : : src = kmap_atomic(s_page);
1381 : : dst = kmap_atomic(d_page);
1382 : : do_copy_page(dst, src);
1383 : : kunmap_atomic(dst);
1384 : : kunmap_atomic(src);
1385 : : } else {
1386 : : if (PageHighMem(d_page)) {
1387 : : /*
1388 : : * The page pointed to by src may contain some kernel
1389 : : * data modified by kmap_atomic()
1390 : : */
1391 : : safe_copy_page(buffer, s_page);
1392 : : dst = kmap_atomic(d_page);
1393 : : copy_page(dst, buffer);
1394 : : kunmap_atomic(dst);
1395 : : } else {
1396 : : safe_copy_page(page_address(d_page), s_page);
1397 : : }
1398 : : }
1399 : : }
1400 : : #else
1401 : : #define page_is_saveable(zone, pfn) saveable_page(zone, pfn)
1402 : :
1403 : 0 : static inline void copy_data_page(unsigned long dst_pfn, unsigned long src_pfn)
1404 : : {
1405 : 0 : safe_copy_page(page_address(pfn_to_page(dst_pfn)),
1406 : 0 : pfn_to_page(src_pfn));
1407 : 0 : }
1408 : : #endif /* CONFIG_HIGHMEM */
1409 : :
1410 : 0 : static void copy_data_pages(struct memory_bitmap *copy_bm,
1411 : : struct memory_bitmap *orig_bm)
1412 : : {
1413 : 0 : struct zone *zone;
1414 : 0 : unsigned long pfn;
1415 : :
1416 [ # # # # ]: 0 : for_each_populated_zone(zone) {
1417 : 0 : unsigned long max_zone_pfn;
1418 : :
1419 : 0 : mark_free_pages(zone);
1420 : 0 : max_zone_pfn = zone_end_pfn(zone);
1421 [ # # ]: 0 : for (pfn = zone->zone_start_pfn; pfn < max_zone_pfn; pfn++)
1422 [ # # ]: 0 : if (page_is_saveable(zone, pfn))
1423 : 0 : memory_bm_set_bit(orig_bm, pfn);
1424 : : }
1425 : 0 : memory_bm_position_reset(orig_bm);
1426 : 0 : memory_bm_position_reset(copy_bm);
1427 : 0 : for(;;) {
1428 : 0 : pfn = memory_bm_next_pfn(orig_bm);
1429 [ # # ]: 0 : if (unlikely(pfn == BM_END_OF_MAP))
1430 : : break;
1431 : 0 : copy_data_page(memory_bm_next_pfn(copy_bm), pfn);
1432 : : }
1433 : 0 : }
1434 : :
1435 : : /* Total number of image pages */
1436 : : static unsigned int nr_copy_pages;
1437 : : /* Number of pages needed for saving the original pfns of the image pages */
1438 : : static unsigned int nr_meta_pages;
1439 : : /*
1440 : : * Numbers of normal and highmem page frames allocated for hibernation image
1441 : : * before suspending devices.
1442 : : */
1443 : : static unsigned int alloc_normal, alloc_highmem;
1444 : : /*
1445 : : * Memory bitmap used for marking saveable pages (during hibernation) or
1446 : : * hibernation image pages (during restore)
1447 : : */
1448 : : static struct memory_bitmap orig_bm;
1449 : : /*
1450 : : * Memory bitmap used during hibernation for marking allocated page frames that
1451 : : * will contain copies of saveable pages. During restore it is initially used
1452 : : * for marking hibernation image pages, but then the set bits from it are
1453 : : * duplicated in @orig_bm and it is released. On highmem systems it is next
1454 : : * used for marking "safe" highmem pages, but it has to be reinitialized for
1455 : : * this purpose.
1456 : : */
1457 : : static struct memory_bitmap copy_bm;
1458 : :
1459 : : /**
1460 : : * swsusp_free - Free pages allocated for hibernation image.
1461 : : *
1462 : : * Image pages are alocated before snapshot creation, so they need to be
1463 : : * released after resume.
1464 : : */
1465 : 0 : void swsusp_free(void)
1466 : : {
1467 : 0 : unsigned long fb_pfn, fr_pfn;
1468 : :
1469 [ # # # # ]: 0 : if (!forbidden_pages_map || !free_pages_map)
1470 : 0 : goto out;
1471 : :
1472 : 0 : memory_bm_position_reset(forbidden_pages_map);
1473 : 0 : memory_bm_position_reset(free_pages_map);
1474 : :
1475 : 0 : loop:
1476 : 0 : fr_pfn = memory_bm_next_pfn(free_pages_map);
1477 : 0 : fb_pfn = memory_bm_next_pfn(forbidden_pages_map);
1478 : :
1479 : : /*
1480 : : * Find the next bit set in both bitmaps. This is guaranteed to
1481 : : * terminate when fb_pfn == fr_pfn == BM_END_OF_MAP.
1482 : : */
1483 : 0 : do {
1484 [ # # ]: 0 : if (fb_pfn < fr_pfn)
1485 : 0 : fb_pfn = memory_bm_next_pfn(forbidden_pages_map);
1486 [ # # ]: 0 : if (fr_pfn < fb_pfn)
1487 : 0 : fr_pfn = memory_bm_next_pfn(free_pages_map);
1488 [ # # ]: 0 : } while (fb_pfn != fr_pfn);
1489 : :
1490 [ # # # # ]: 0 : if (fr_pfn != BM_END_OF_MAP && pfn_valid(fr_pfn)) {
1491 : 0 : struct page *page = pfn_to_page(fr_pfn);
1492 : :
1493 : 0 : memory_bm_clear_current(forbidden_pages_map);
1494 : 0 : memory_bm_clear_current(free_pages_map);
1495 [ # # ]: 0 : hibernate_restore_unprotect_page(page_address(page));
1496 : 0 : __free_page(page);
1497 : 0 : goto loop;
1498 : : }
1499 : :
1500 : 0 : out:
1501 : 0 : nr_copy_pages = 0;
1502 : 0 : nr_meta_pages = 0;
1503 : 0 : restore_pblist = NULL;
1504 : 0 : buffer = NULL;
1505 : 0 : alloc_normal = 0;
1506 : 0 : alloc_highmem = 0;
1507 : 0 : hibernate_restore_protection_end();
1508 : 0 : }
1509 : :
1510 : : /* Helper functions used for the shrinking of memory. */
1511 : :
1512 : : #define GFP_IMAGE (GFP_KERNEL | __GFP_NOWARN)
1513 : :
1514 : : /**
1515 : : * preallocate_image_pages - Allocate a number of pages for hibernation image.
1516 : : * @nr_pages: Number of page frames to allocate.
1517 : : * @mask: GFP flags to use for the allocation.
1518 : : *
1519 : : * Return value: Number of page frames actually allocated
1520 : : */
1521 : 0 : static unsigned long preallocate_image_pages(unsigned long nr_pages, gfp_t mask)
1522 : : {
1523 : 0 : unsigned long nr_alloc = 0;
1524 : :
1525 [ # # ]: 0 : while (nr_pages > 0) {
1526 : 0 : struct page *page;
1527 : :
1528 : 0 : page = alloc_image_page(mask);
1529 [ # # ]: 0 : if (!page)
1530 : : break;
1531 : 0 : memory_bm_set_bit(©_bm, page_to_pfn(page));
1532 : 0 : if (PageHighMem(page))
1533 : : alloc_highmem++;
1534 : : else
1535 : 0 : alloc_normal++;
1536 : 0 : nr_pages--;
1537 : 0 : nr_alloc++;
1538 : : }
1539 : :
1540 : 0 : return nr_alloc;
1541 : : }
1542 : :
1543 : 0 : static unsigned long preallocate_image_memory(unsigned long nr_pages,
1544 : : unsigned long avail_normal)
1545 : : {
1546 : 0 : unsigned long alloc;
1547 : :
1548 : 0 : if (avail_normal <= alloc_normal)
1549 : : return 0;
1550 : :
1551 : 0 : alloc = avail_normal - alloc_normal;
1552 : 0 : if (nr_pages < alloc)
1553 : : alloc = nr_pages;
1554 : :
1555 : 0 : return preallocate_image_pages(alloc, GFP_IMAGE);
1556 : : }
1557 : :
1558 : : #ifdef CONFIG_HIGHMEM
1559 : : static unsigned long preallocate_image_highmem(unsigned long nr_pages)
1560 : : {
1561 : : return preallocate_image_pages(nr_pages, GFP_IMAGE | __GFP_HIGHMEM);
1562 : : }
1563 : :
1564 : : /**
1565 : : * __fraction - Compute (an approximation of) x * (multiplier / base).
1566 : : */
1567 : : static unsigned long __fraction(u64 x, u64 multiplier, u64 base)
1568 : : {
1569 : : return div64_u64(x * multiplier, base);
1570 : : }
1571 : :
1572 : : static unsigned long preallocate_highmem_fraction(unsigned long nr_pages,
1573 : : unsigned long highmem,
1574 : : unsigned long total)
1575 : : {
1576 : : unsigned long alloc = __fraction(nr_pages, highmem, total);
1577 : :
1578 : : return preallocate_image_pages(alloc, GFP_IMAGE | __GFP_HIGHMEM);
1579 : : }
1580 : : #else /* CONFIG_HIGHMEM */
1581 : 0 : static inline unsigned long preallocate_image_highmem(unsigned long nr_pages)
1582 : : {
1583 : 0 : return 0;
1584 : : }
1585 : :
1586 : 0 : static inline unsigned long preallocate_highmem_fraction(unsigned long nr_pages,
1587 : : unsigned long highmem,
1588 : : unsigned long total)
1589 : : {
1590 : 0 : return 0;
1591 : : }
1592 : : #endif /* CONFIG_HIGHMEM */
1593 : :
1594 : : /**
1595 : : * free_unnecessary_pages - Release preallocated pages not needed for the image.
1596 : : */
1597 : 0 : static unsigned long free_unnecessary_pages(void)
1598 : : {
1599 : 0 : unsigned long save, to_free_normal, to_free_highmem, free;
1600 : :
1601 : 0 : save = count_data_pages();
1602 [ # # ]: 0 : if (alloc_normal >= save) {
1603 : 0 : to_free_normal = alloc_normal - save;
1604 : 0 : save = 0;
1605 : : } else {
1606 : 0 : to_free_normal = 0;
1607 : 0 : save -= alloc_normal;
1608 : : }
1609 [ # # ]: 0 : save += count_highmem_pages();
1610 [ # # ]: 0 : if (alloc_highmem >= save) {
1611 : 0 : to_free_highmem = alloc_highmem - save;
1612 : : } else {
1613 : 0 : to_free_highmem = 0;
1614 : 0 : save -= alloc_highmem;
1615 [ # # ]: 0 : if (to_free_normal > save)
1616 : 0 : to_free_normal -= save;
1617 : : else
1618 : : to_free_normal = 0;
1619 : : }
1620 : 0 : free = to_free_normal + to_free_highmem;
1621 : :
1622 : 0 : memory_bm_position_reset(©_bm);
1623 : :
1624 [ # # ]: 0 : while (to_free_normal > 0 || to_free_highmem > 0) {
1625 : 0 : unsigned long pfn = memory_bm_next_pfn(©_bm);
1626 : 0 : struct page *page = pfn_to_page(pfn);
1627 : :
1628 [ # # ]: 0 : if (PageHighMem(page)) {
1629 : : if (!to_free_highmem)
1630 : : continue;
1631 : : to_free_highmem--;
1632 : : alloc_highmem--;
1633 : : } else {
1634 [ # # ]: 0 : if (!to_free_normal)
1635 : 0 : continue;
1636 : 0 : to_free_normal--;
1637 : 0 : alloc_normal--;
1638 : : }
1639 : 0 : memory_bm_clear_bit(©_bm, pfn);
1640 [ # # ]: 0 : swsusp_unset_page_forbidden(page);
1641 [ # # ]: 0 : swsusp_unset_page_free(page);
1642 : 0 : __free_page(page);
1643 : : }
1644 : :
1645 : 0 : return free;
1646 : : }
1647 : :
1648 : : /**
1649 : : * minimum_image_size - Estimate the minimum acceptable size of an image.
1650 : : * @saveable: Number of saveable pages in the system.
1651 : : *
1652 : : * We want to avoid attempting to free too much memory too hard, so estimate the
1653 : : * minimum acceptable size of a hibernation image to use as the lower limit for
1654 : : * preallocating memory.
1655 : : *
1656 : : * We assume that the minimum image size should be proportional to
1657 : : *
1658 : : * [number of saveable pages] - [number of pages that can be freed in theory]
1659 : : *
1660 : : * where the second term is the sum of (1) reclaimable slab pages, (2) active
1661 : : * and (3) inactive anonymous pages, (4) active and (5) inactive file pages.
1662 : : */
1663 : 0 : static unsigned long minimum_image_size(unsigned long saveable)
1664 : : {
1665 : 0 : unsigned long size;
1666 : :
1667 : 0 : size = global_node_page_state(NR_SLAB_RECLAIMABLE)
1668 : 0 : + global_node_page_state(NR_ACTIVE_ANON)
1669 : 0 : + global_node_page_state(NR_INACTIVE_ANON)
1670 : 0 : + global_node_page_state(NR_ACTIVE_FILE)
1671 : : + global_node_page_state(NR_INACTIVE_FILE);
1672 : :
1673 [ # # ]: 0 : return saveable <= size ? 0 : saveable - size;
1674 : : }
1675 : :
1676 : : /**
1677 : : * hibernate_preallocate_memory - Preallocate memory for hibernation image.
1678 : : *
1679 : : * To create a hibernation image it is necessary to make a copy of every page
1680 : : * frame in use. We also need a number of page frames to be free during
1681 : : * hibernation for allocations made while saving the image and for device
1682 : : * drivers, in case they need to allocate memory from their hibernation
1683 : : * callbacks (these two numbers are given by PAGES_FOR_IO (which is a rough
1684 : : * estimate) and reserved_size divided by PAGE_SIZE (which is tunable through
1685 : : * /sys/power/reserved_size, respectively). To make this happen, we compute the
1686 : : * total number of available page frames and allocate at least
1687 : : *
1688 : : * ([page frames total] + PAGES_FOR_IO + [metadata pages]) / 2
1689 : : * + 2 * DIV_ROUND_UP(reserved_size, PAGE_SIZE)
1690 : : *
1691 : : * of them, which corresponds to the maximum size of a hibernation image.
1692 : : *
1693 : : * If image_size is set below the number following from the above formula,
1694 : : * the preallocation of memory is continued until the total number of saveable
1695 : : * pages in the system is below the requested image size or the minimum
1696 : : * acceptable image size returned by minimum_image_size(), whichever is greater.
1697 : : */
1698 : 0 : int hibernate_preallocate_memory(void)
1699 : : {
1700 : 0 : struct zone *zone;
1701 : 0 : unsigned long saveable, size, max_size, count, highmem, pages = 0;
1702 : 0 : unsigned long alloc, save_highmem, pages_highmem, avail_normal;
1703 : 0 : ktime_t start, stop;
1704 : 0 : int error;
1705 : :
1706 : 0 : pr_info("Preallocating image memory\n");
1707 : 0 : start = ktime_get();
1708 : :
1709 : 0 : error = memory_bm_create(&orig_bm, GFP_IMAGE, PG_ANY);
1710 [ # # ]: 0 : if (error) {
1711 : 0 : pr_err("Cannot allocate original bitmap\n");
1712 : 0 : goto err_out;
1713 : : }
1714 : :
1715 : 0 : error = memory_bm_create(©_bm, GFP_IMAGE, PG_ANY);
1716 [ # # ]: 0 : if (error) {
1717 : 0 : pr_err("Cannot allocate copy bitmap\n");
1718 : 0 : goto err_out;
1719 : : }
1720 : :
1721 : 0 : alloc_normal = 0;
1722 : 0 : alloc_highmem = 0;
1723 : :
1724 : : /* Count the number of saveable data pages. */
1725 : 0 : save_highmem = count_highmem_pages();
1726 : 0 : saveable = count_data_pages();
1727 : :
1728 : : /*
1729 : : * Compute the total number of page frames we can use (count) and the
1730 : : * number of pages needed for image metadata (size).
1731 : : */
1732 : 0 : count = saveable;
1733 : 0 : saveable += save_highmem;
1734 : 0 : highmem = save_highmem;
1735 : 0 : size = 0;
1736 [ # # # # ]: 0 : for_each_populated_zone(zone) {
1737 : 0 : size += snapshot_additional_pages(zone);
1738 : 0 : if (is_highmem(zone))
1739 : : highmem += zone_page_state(zone, NR_FREE_PAGES);
1740 : : else
1741 : 0 : count += zone_page_state(zone, NR_FREE_PAGES);
1742 : : }
1743 : 0 : avail_normal = count;
1744 : 0 : count += highmem;
1745 : 0 : count -= totalreserve_pages;
1746 : :
1747 : : /* Add number of pages required for page keys (s390 only). */
1748 [ # # ]: 0 : size += page_key_additional_pages(saveable);
1749 : :
1750 : : /* Compute the maximum number of saveable pages to leave in memory. */
1751 : 0 : max_size = (count - (size + PAGES_FOR_IO)) / 2
1752 : 0 : - 2 * DIV_ROUND_UP(reserved_size, PAGE_SIZE);
1753 : : /* Compute the desired number of image pages specified by image_size. */
1754 : 0 : size = DIV_ROUND_UP(image_size, PAGE_SIZE);
1755 : 0 : if (size > max_size)
1756 : : size = max_size;
1757 : : /*
1758 : : * If the desired number of image pages is at least as large as the
1759 : : * current number of saveable pages in memory, allocate page frames for
1760 : : * the image and we're done.
1761 : : */
1762 [ # # ]: 0 : if (size >= saveable) {
1763 : 0 : pages = preallocate_image_highmem(save_highmem);
1764 [ # # ]: 0 : pages += preallocate_image_memory(saveable - pages, avail_normal);
1765 : 0 : goto out;
1766 : : }
1767 : :
1768 : : /* Estimate the minimum size of the image. */
1769 [ # # ]: 0 : pages = minimum_image_size(saveable);
1770 : : /*
1771 : : * To avoid excessive pressure on the normal zone, leave room in it to
1772 : : * accommodate an image of the minimum size (unless it's already too
1773 : : * small, in which case don't preallocate pages from it at all).
1774 : : */
1775 [ # # ]: 0 : if (avail_normal > pages)
1776 : 0 : avail_normal -= pages;
1777 : : else
1778 : : avail_normal = 0;
1779 [ # # ]: 0 : if (size < pages)
1780 : 0 : size = min_t(unsigned long, pages, max_size);
1781 : :
1782 : : /*
1783 : : * Let the memory management subsystem know that we're going to need a
1784 : : * large number of page frames to allocate and make it free some memory.
1785 : : * NOTE: If this is not done, performance will be hurt badly in some
1786 : : * test cases.
1787 : : */
1788 : 0 : shrink_all_memory(saveable - size);
1789 : :
1790 : : /*
1791 : : * The number of saveable pages in memory was too high, so apply some
1792 : : * pressure to decrease it. First, make room for the largest possible
1793 : : * image and fail if that doesn't work. Next, try to decrease the size
1794 : : * of the image as much as indicated by 'size' using allocations from
1795 : : * highmem and non-highmem zones separately.
1796 : : */
1797 : 0 : pages_highmem = preallocate_image_highmem(highmem / 2);
1798 : 0 : alloc = count - max_size;
1799 : 0 : if (alloc > pages_highmem)
1800 : : alloc -= pages_highmem;
1801 : : else
1802 : : alloc = 0;
1803 [ # # ]: 0 : pages = preallocate_image_memory(alloc, avail_normal);
1804 [ # # ]: 0 : if (pages < alloc) {
1805 : : /* We have exhausted non-highmem pages, try highmem. */
1806 : 0 : alloc -= pages;
1807 : 0 : pages += pages_highmem;
1808 : 0 : pages_highmem = preallocate_image_highmem(alloc);
1809 [ # # ]: 0 : if (pages_highmem < alloc) {
1810 : 0 : pr_err("Image allocation is %lu pages short\n",
1811 : : alloc - pages_highmem);
1812 : 0 : goto err_out;
1813 : : }
1814 : : pages += pages_highmem;
1815 : : /*
1816 : : * size is the desired number of saveable pages to leave in
1817 : : * memory, so try to preallocate (all memory - size) pages.
1818 : : */
1819 : : alloc = (count - pages) - size;
1820 : : pages += preallocate_image_highmem(alloc);
1821 : : } else {
1822 : : /*
1823 : : * There are approximately max_size saveable pages at this point
1824 : : * and we want to reduce this number down to size.
1825 : : */
1826 : 0 : alloc = max_size - size;
1827 : 0 : size = preallocate_highmem_fraction(alloc, highmem, count);
1828 : 0 : pages_highmem += size;
1829 : 0 : alloc -= size;
1830 [ # # ]: 0 : size = preallocate_image_memory(alloc, avail_normal);
1831 : 0 : pages_highmem += preallocate_image_highmem(alloc - size);
1832 : 0 : pages += pages_highmem + size;
1833 : : }
1834 : :
1835 : : /*
1836 : : * We only need as many page frames for the image as there are saveable
1837 : : * pages in memory, but we have allocated more. Release the excessive
1838 : : * ones now.
1839 : : */
1840 : 0 : pages -= free_unnecessary_pages();
1841 : :
1842 : 0 : out:
1843 : 0 : stop = ktime_get();
1844 : 0 : pr_info("Allocated %lu pages for snapshot\n", pages);
1845 : 0 : swsusp_show_speed(start, stop, pages, "Allocated");
1846 : :
1847 : 0 : return 0;
1848 : :
1849 : 0 : err_out:
1850 : 0 : swsusp_free();
1851 : 0 : return -ENOMEM;
1852 : : }
1853 : :
1854 : : #ifdef CONFIG_HIGHMEM
1855 : : /**
1856 : : * count_pages_for_highmem - Count non-highmem pages needed for copying highmem.
1857 : : *
1858 : : * Compute the number of non-highmem pages that will be necessary for creating
1859 : : * copies of highmem pages.
1860 : : */
1861 : : static unsigned int count_pages_for_highmem(unsigned int nr_highmem)
1862 : : {
1863 : : unsigned int free_highmem = count_free_highmem_pages() + alloc_highmem;
1864 : :
1865 : : if (free_highmem >= nr_highmem)
1866 : : nr_highmem = 0;
1867 : : else
1868 : : nr_highmem -= free_highmem;
1869 : :
1870 : : return nr_highmem;
1871 : : }
1872 : : #else
1873 : : static unsigned int count_pages_for_highmem(unsigned int nr_highmem) { return 0; }
1874 : : #endif /* CONFIG_HIGHMEM */
1875 : :
1876 : : /**
1877 : : * enough_free_mem - Check if there is enough free memory for the image.
1878 : : */
1879 : : static int enough_free_mem(unsigned int nr_pages, unsigned int nr_highmem)
1880 : : {
1881 : : struct zone *zone;
1882 : : unsigned int free = alloc_normal;
1883 : :
1884 : : for_each_populated_zone(zone)
1885 : : if (!is_highmem(zone))
1886 : : free += zone_page_state(zone, NR_FREE_PAGES);
1887 : :
1888 : : nr_pages += count_pages_for_highmem(nr_highmem);
1889 : : pr_debug("Normal pages needed: %u + %u, available pages: %u\n",
1890 : : nr_pages, PAGES_FOR_IO, free);
1891 : :
1892 : : return free > nr_pages + PAGES_FOR_IO;
1893 : : }
1894 : :
1895 : : #ifdef CONFIG_HIGHMEM
1896 : : /**
1897 : : * get_highmem_buffer - Allocate a buffer for highmem pages.
1898 : : *
1899 : : * If there are some highmem pages in the hibernation image, we may need a
1900 : : * buffer to copy them and/or load their data.
1901 : : */
1902 : : static inline int get_highmem_buffer(int safe_needed)
1903 : : {
1904 : : buffer = get_image_page(GFP_ATOMIC, safe_needed);
1905 : : return buffer ? 0 : -ENOMEM;
1906 : : }
1907 : :
1908 : : /**
1909 : : * alloc_highmem_image_pages - Allocate some highmem pages for the image.
1910 : : *
1911 : : * Try to allocate as many pages as needed, but if the number of free highmem
1912 : : * pages is less than that, allocate them all.
1913 : : */
1914 : : static inline unsigned int alloc_highmem_pages(struct memory_bitmap *bm,
1915 : : unsigned int nr_highmem)
1916 : : {
1917 : : unsigned int to_alloc = count_free_highmem_pages();
1918 : :
1919 : : if (to_alloc > nr_highmem)
1920 : : to_alloc = nr_highmem;
1921 : :
1922 : : nr_highmem -= to_alloc;
1923 : : while (to_alloc-- > 0) {
1924 : : struct page *page;
1925 : :
1926 : : page = alloc_image_page(__GFP_HIGHMEM|__GFP_KSWAPD_RECLAIM);
1927 : : memory_bm_set_bit(bm, page_to_pfn(page));
1928 : : }
1929 : : return nr_highmem;
1930 : : }
1931 : : #else
1932 : : static inline int get_highmem_buffer(int safe_needed) { return 0; }
1933 : :
1934 : : static inline unsigned int alloc_highmem_pages(struct memory_bitmap *bm,
1935 : : unsigned int n) { return 0; }
1936 : : #endif /* CONFIG_HIGHMEM */
1937 : :
1938 : : /**
1939 : : * swsusp_alloc - Allocate memory for hibernation image.
1940 : : *
1941 : : * We first try to allocate as many highmem pages as there are
1942 : : * saveable highmem pages in the system. If that fails, we allocate
1943 : : * non-highmem pages for the copies of the remaining highmem ones.
1944 : : *
1945 : : * In this approach it is likely that the copies of highmem pages will
1946 : : * also be located in the high memory, because of the way in which
1947 : : * copy_data_pages() works.
1948 : : */
1949 : : static int swsusp_alloc(struct memory_bitmap *copy_bm,
1950 : : unsigned int nr_pages, unsigned int nr_highmem)
1951 : : {
1952 : : if (nr_highmem > 0) {
1953 : : if (get_highmem_buffer(PG_ANY))
1954 : : goto err_out;
1955 : : if (nr_highmem > alloc_highmem) {
1956 : : nr_highmem -= alloc_highmem;
1957 : : nr_pages += alloc_highmem_pages(copy_bm, nr_highmem);
1958 : : }
1959 : : }
1960 : : if (nr_pages > alloc_normal) {
1961 : : nr_pages -= alloc_normal;
1962 : : while (nr_pages-- > 0) {
1963 : : struct page *page;
1964 : :
1965 : : page = alloc_image_page(GFP_ATOMIC);
1966 : : if (!page)
1967 : : goto err_out;
1968 : : memory_bm_set_bit(copy_bm, page_to_pfn(page));
1969 : : }
1970 : : }
1971 : :
1972 : : return 0;
1973 : :
1974 : : err_out:
1975 : : swsusp_free();
1976 : : return -ENOMEM;
1977 : : }
1978 : :
1979 : 0 : asmlinkage __visible int swsusp_save(void)
1980 : : {
1981 : 0 : unsigned int nr_pages, nr_highmem;
1982 : :
1983 : 0 : pr_info("Creating image:\n");
1984 : :
1985 : 0 : drain_local_pages(NULL);
1986 : 0 : nr_pages = count_data_pages();
1987 : 0 : nr_highmem = count_highmem_pages();
1988 : 0 : pr_info("Need to copy %u pages\n", nr_pages + nr_highmem);
1989 : :
1990 [ # # ]: 0 : if (!enough_free_mem(nr_pages, nr_highmem)) {
1991 : 0 : pr_err("Not enough free memory\n");
1992 : 0 : return -ENOMEM;
1993 : : }
1994 : :
1995 [ # # ]: 0 : if (swsusp_alloc(©_bm, nr_pages, nr_highmem)) {
1996 : 0 : pr_err("Memory allocation failed\n");
1997 : 0 : return -ENOMEM;
1998 : : }
1999 : :
2000 : : /*
2001 : : * During allocating of suspend pagedir, new cold pages may appear.
2002 : : * Kill them.
2003 : : */
2004 : 0 : drain_local_pages(NULL);
2005 : 0 : copy_data_pages(©_bm, &orig_bm);
2006 : :
2007 : : /*
2008 : : * End of critical section. From now on, we can write to memory,
2009 : : * but we should not touch disk. This specially means we must _not_
2010 : : * touch swap space! Except we must write out our image of course.
2011 : : */
2012 : :
2013 : 0 : nr_pages += nr_highmem;
2014 : 0 : nr_copy_pages = nr_pages;
2015 : 0 : nr_meta_pages = DIV_ROUND_UP(nr_pages * sizeof(long), PAGE_SIZE);
2016 : :
2017 : 0 : pr_info("Image created (%d pages copied)\n", nr_pages);
2018 : :
2019 : 0 : return 0;
2020 : : }
2021 : :
2022 : : #ifndef CONFIG_ARCH_HIBERNATION_HEADER
2023 : : static int init_header_complete(struct swsusp_info *info)
2024 : : {
2025 : : memcpy(&info->uts, init_utsname(), sizeof(struct new_utsname));
2026 : : info->version_code = LINUX_VERSION_CODE;
2027 : : return 0;
2028 : : }
2029 : :
2030 : : static char *check_image_kernel(struct swsusp_info *info)
2031 : : {
2032 : : if (info->version_code != LINUX_VERSION_CODE)
2033 : : return "kernel version";
2034 : : if (strcmp(info->uts.sysname,init_utsname()->sysname))
2035 : : return "system type";
2036 : : if (strcmp(info->uts.release,init_utsname()->release))
2037 : : return "kernel release";
2038 : : if (strcmp(info->uts.version,init_utsname()->version))
2039 : : return "version";
2040 : : if (strcmp(info->uts.machine,init_utsname()->machine))
2041 : : return "machine";
2042 : : return NULL;
2043 : : }
2044 : : #endif /* CONFIG_ARCH_HIBERNATION_HEADER */
2045 : :
2046 : 0 : unsigned long snapshot_get_image_size(void)
2047 : : {
2048 : 0 : return nr_copy_pages + nr_meta_pages + 1;
2049 : : }
2050 : :
2051 : 0 : static int init_header(struct swsusp_info *info)
2052 : : {
2053 : 0 : memset(info, 0, sizeof(struct swsusp_info));
2054 : 0 : info->num_physpages = get_num_physpages();
2055 : 0 : info->image_pages = nr_copy_pages;
2056 : 0 : info->pages = snapshot_get_image_size();
2057 : 0 : info->size = info->pages;
2058 : 0 : info->size <<= PAGE_SHIFT;
2059 : 0 : return init_header_complete(info);
2060 : : }
2061 : :
2062 : : /**
2063 : : * pack_pfns - Prepare PFNs for saving.
2064 : : * @bm: Memory bitmap.
2065 : : * @buf: Memory buffer to store the PFNs in.
2066 : : *
2067 : : * PFNs corresponding to set bits in @bm are stored in the area of memory
2068 : : * pointed to by @buf (1 page at a time).
2069 : : */
2070 : 0 : static inline void pack_pfns(unsigned long *buf, struct memory_bitmap *bm)
2071 : : {
2072 : 0 : int j;
2073 : :
2074 [ # # ]: 0 : for (j = 0; j < PAGE_SIZE / sizeof(long); j++) {
2075 : 0 : buf[j] = memory_bm_next_pfn(bm);
2076 [ # # ]: 0 : if (unlikely(buf[j] == BM_END_OF_MAP))
2077 : : break;
2078 : : /* Save page key for data page (s390 only). */
2079 : 0 : page_key_read(buf + j);
2080 : : }
2081 : 0 : }
2082 : :
2083 : : /**
2084 : : * snapshot_read_next - Get the address to read the next image page from.
2085 : : * @handle: Snapshot handle to be used for the reading.
2086 : : *
2087 : : * On the first call, @handle should point to a zeroed snapshot_handle
2088 : : * structure. The structure gets populated then and a pointer to it should be
2089 : : * passed to this function every next time.
2090 : : *
2091 : : * On success, the function returns a positive number. Then, the caller
2092 : : * is allowed to read up to the returned number of bytes from the memory
2093 : : * location computed by the data_of() macro.
2094 : : *
2095 : : * The function returns 0 to indicate the end of the data stream condition,
2096 : : * and negative numbers are returned on errors. If that happens, the structure
2097 : : * pointed to by @handle is not updated and should not be used any more.
2098 : : */
2099 : 0 : int snapshot_read_next(struct snapshot_handle *handle)
2100 : : {
2101 [ # # ]: 0 : if (handle->cur > nr_meta_pages + nr_copy_pages)
2102 : : return 0;
2103 : :
2104 [ # # ]: 0 : if (!buffer) {
2105 : : /* This makes the buffer be freed by swsusp_free() */
2106 : 0 : buffer = get_image_page(GFP_ATOMIC, PG_ANY);
2107 [ # # ]: 0 : if (!buffer)
2108 : : return -ENOMEM;
2109 : : }
2110 [ # # ]: 0 : if (!handle->cur) {
2111 : 0 : int error;
2112 : :
2113 : 0 : error = init_header((struct swsusp_info *)buffer);
2114 [ # # ]: 0 : if (error)
2115 : : return error;
2116 : 0 : handle->buffer = buffer;
2117 : 0 : memory_bm_position_reset(&orig_bm);
2118 : 0 : memory_bm_position_reset(©_bm);
2119 [ # # ]: 0 : } else if (handle->cur <= nr_meta_pages) {
2120 : 0 : clear_page(buffer);
2121 : 0 : pack_pfns(buffer, &orig_bm);
2122 : : } else {
2123 : 0 : struct page *page;
2124 : :
2125 : 0 : page = pfn_to_page(memory_bm_next_pfn(©_bm));
2126 : 0 : if (PageHighMem(page)) {
2127 : : /*
2128 : : * Highmem pages are copied to the buffer,
2129 : : * because we can't return with a kmapped
2130 : : * highmem page (we may not be called again).
2131 : : */
2132 : : void *kaddr;
2133 : :
2134 : : kaddr = kmap_atomic(page);
2135 : : copy_page(buffer, kaddr);
2136 : : kunmap_atomic(kaddr);
2137 : : handle->buffer = buffer;
2138 : : } else {
2139 : 0 : handle->buffer = page_address(page);
2140 : : }
2141 : : }
2142 : 0 : handle->cur++;
2143 : 0 : return PAGE_SIZE;
2144 : : }
2145 : :
2146 : 0 : static void duplicate_memory_bitmap(struct memory_bitmap *dst,
2147 : : struct memory_bitmap *src)
2148 : : {
2149 : 0 : unsigned long pfn;
2150 : :
2151 : 0 : memory_bm_position_reset(src);
2152 : 0 : pfn = memory_bm_next_pfn(src);
2153 [ # # ]: 0 : while (pfn != BM_END_OF_MAP) {
2154 : 0 : memory_bm_set_bit(dst, pfn);
2155 : 0 : pfn = memory_bm_next_pfn(src);
2156 : : }
2157 : 0 : }
2158 : :
2159 : : /**
2160 : : * mark_unsafe_pages - Mark pages that were used before hibernation.
2161 : : *
2162 : : * Mark the pages that cannot be used for storing the image during restoration,
2163 : : * because they conflict with the pages that had been used before hibernation.
2164 : : */
2165 : 0 : static void mark_unsafe_pages(struct memory_bitmap *bm)
2166 : : {
2167 : 0 : unsigned long pfn;
2168 : :
2169 : : /* Clear the "free"/"unsafe" bit for all PFNs */
2170 : 0 : memory_bm_position_reset(free_pages_map);
2171 : 0 : pfn = memory_bm_next_pfn(free_pages_map);
2172 [ # # ]: 0 : while (pfn != BM_END_OF_MAP) {
2173 : 0 : memory_bm_clear_current(free_pages_map);
2174 : 0 : pfn = memory_bm_next_pfn(free_pages_map);
2175 : : }
2176 : :
2177 : : /* Mark pages that correspond to the "original" PFNs as "unsafe" */
2178 : 0 : duplicate_memory_bitmap(free_pages_map, bm);
2179 : :
2180 : 0 : allocated_unsafe_pages = 0;
2181 : 0 : }
2182 : :
2183 : 0 : static int check_header(struct swsusp_info *info)
2184 : : {
2185 : 0 : char *reason;
2186 : :
2187 : 0 : reason = check_image_kernel(info);
2188 [ # # ]: 0 : if (!reason && info->num_physpages != get_num_physpages())
2189 : 0 : reason = "memory size";
2190 [ # # ]: 0 : if (reason) {
2191 : 0 : pr_err("Image mismatch: %s\n", reason);
2192 : 0 : return -EPERM;
2193 : : }
2194 : : return 0;
2195 : : }
2196 : :
2197 : : /**
2198 : : * load header - Check the image header and copy the data from it.
2199 : : */
2200 : 0 : static int load_header(struct swsusp_info *info)
2201 : : {
2202 : 0 : int error;
2203 : :
2204 : 0 : restore_pblist = NULL;
2205 : 0 : error = check_header(info);
2206 [ # # ]: 0 : if (!error) {
2207 : 0 : nr_copy_pages = info->image_pages;
2208 : 0 : nr_meta_pages = info->pages - info->image_pages - 1;
2209 : : }
2210 : 0 : return error;
2211 : : }
2212 : :
2213 : : /**
2214 : : * unpack_orig_pfns - Set bits corresponding to given PFNs in a memory bitmap.
2215 : : * @bm: Memory bitmap.
2216 : : * @buf: Area of memory containing the PFNs.
2217 : : *
2218 : : * For each element of the array pointed to by @buf (1 page at a time), set the
2219 : : * corresponding bit in @bm.
2220 : : */
2221 : 0 : static int unpack_orig_pfns(unsigned long *buf, struct memory_bitmap *bm)
2222 : : {
2223 : 0 : int j;
2224 : :
2225 [ # # ]: 0 : for (j = 0; j < PAGE_SIZE / sizeof(long); j++) {
2226 [ # # ]: 0 : if (unlikely(buf[j] == BM_END_OF_MAP))
2227 : : break;
2228 : :
2229 : : /* Extract and buffer page key for data page (s390 only). */
2230 : 0 : page_key_memorize(buf + j);
2231 : :
2232 [ # # # # ]: 0 : if (pfn_valid(buf[j]) && memory_bm_pfn_present(bm, buf[j]))
2233 : 0 : memory_bm_set_bit(bm, buf[j]);
2234 : : else
2235 : 0 : return -EFAULT;
2236 : : }
2237 : :
2238 : : return 0;
2239 : : }
2240 : :
2241 : : #ifdef CONFIG_HIGHMEM
2242 : : /*
2243 : : * struct highmem_pbe is used for creating the list of highmem pages that
2244 : : * should be restored atomically during the resume from disk, because the page
2245 : : * frames they have occupied before the suspend are in use.
2246 : : */
2247 : : struct highmem_pbe {
2248 : : struct page *copy_page; /* data is here now */
2249 : : struct page *orig_page; /* data was here before the suspend */
2250 : : struct highmem_pbe *next;
2251 : : };
2252 : :
2253 : : /*
2254 : : * List of highmem PBEs needed for restoring the highmem pages that were
2255 : : * allocated before the suspend and included in the suspend image, but have
2256 : : * also been allocated by the "resume" kernel, so their contents cannot be
2257 : : * written directly to their "original" page frames.
2258 : : */
2259 : : static struct highmem_pbe *highmem_pblist;
2260 : :
2261 : : /**
2262 : : * count_highmem_image_pages - Compute the number of highmem pages in the image.
2263 : : * @bm: Memory bitmap.
2264 : : *
2265 : : * The bits in @bm that correspond to image pages are assumed to be set.
2266 : : */
2267 : : static unsigned int count_highmem_image_pages(struct memory_bitmap *bm)
2268 : : {
2269 : : unsigned long pfn;
2270 : : unsigned int cnt = 0;
2271 : :
2272 : : memory_bm_position_reset(bm);
2273 : : pfn = memory_bm_next_pfn(bm);
2274 : : while (pfn != BM_END_OF_MAP) {
2275 : : if (PageHighMem(pfn_to_page(pfn)))
2276 : : cnt++;
2277 : :
2278 : : pfn = memory_bm_next_pfn(bm);
2279 : : }
2280 : : return cnt;
2281 : : }
2282 : :
2283 : : static unsigned int safe_highmem_pages;
2284 : :
2285 : : static struct memory_bitmap *safe_highmem_bm;
2286 : :
2287 : : /**
2288 : : * prepare_highmem_image - Allocate memory for loading highmem data from image.
2289 : : * @bm: Pointer to an uninitialized memory bitmap structure.
2290 : : * @nr_highmem_p: Pointer to the number of highmem image pages.
2291 : : *
2292 : : * Try to allocate as many highmem pages as there are highmem image pages
2293 : : * (@nr_highmem_p points to the variable containing the number of highmem image
2294 : : * pages). The pages that are "safe" (ie. will not be overwritten when the
2295 : : * hibernation image is restored entirely) have the corresponding bits set in
2296 : : * @bm (it must be unitialized).
2297 : : *
2298 : : * NOTE: This function should not be called if there are no highmem image pages.
2299 : : */
2300 : : static int prepare_highmem_image(struct memory_bitmap *bm,
2301 : : unsigned int *nr_highmem_p)
2302 : : {
2303 : : unsigned int to_alloc;
2304 : :
2305 : : if (memory_bm_create(bm, GFP_ATOMIC, PG_SAFE))
2306 : : return -ENOMEM;
2307 : :
2308 : : if (get_highmem_buffer(PG_SAFE))
2309 : : return -ENOMEM;
2310 : :
2311 : : to_alloc = count_free_highmem_pages();
2312 : : if (to_alloc > *nr_highmem_p)
2313 : : to_alloc = *nr_highmem_p;
2314 : : else
2315 : : *nr_highmem_p = to_alloc;
2316 : :
2317 : : safe_highmem_pages = 0;
2318 : : while (to_alloc-- > 0) {
2319 : : struct page *page;
2320 : :
2321 : : page = alloc_page(__GFP_HIGHMEM);
2322 : : if (!swsusp_page_is_free(page)) {
2323 : : /* The page is "safe", set its bit the bitmap */
2324 : : memory_bm_set_bit(bm, page_to_pfn(page));
2325 : : safe_highmem_pages++;
2326 : : }
2327 : : /* Mark the page as allocated */
2328 : : swsusp_set_page_forbidden(page);
2329 : : swsusp_set_page_free(page);
2330 : : }
2331 : : memory_bm_position_reset(bm);
2332 : : safe_highmem_bm = bm;
2333 : : return 0;
2334 : : }
2335 : :
2336 : : static struct page *last_highmem_page;
2337 : :
2338 : : /**
2339 : : * get_highmem_page_buffer - Prepare a buffer to store a highmem image page.
2340 : : *
2341 : : * For a given highmem image page get a buffer that suspend_write_next() should
2342 : : * return to its caller to write to.
2343 : : *
2344 : : * If the page is to be saved to its "original" page frame or a copy of
2345 : : * the page is to be made in the highmem, @buffer is returned. Otherwise,
2346 : : * the copy of the page is to be made in normal memory, so the address of
2347 : : * the copy is returned.
2348 : : *
2349 : : * If @buffer is returned, the caller of suspend_write_next() will write
2350 : : * the page's contents to @buffer, so they will have to be copied to the
2351 : : * right location on the next call to suspend_write_next() and it is done
2352 : : * with the help of copy_last_highmem_page(). For this purpose, if
2353 : : * @buffer is returned, @last_highmem_page is set to the page to which
2354 : : * the data will have to be copied from @buffer.
2355 : : */
2356 : : static void *get_highmem_page_buffer(struct page *page,
2357 : : struct chain_allocator *ca)
2358 : : {
2359 : : struct highmem_pbe *pbe;
2360 : : void *kaddr;
2361 : :
2362 : : if (swsusp_page_is_forbidden(page) && swsusp_page_is_free(page)) {
2363 : : /*
2364 : : * We have allocated the "original" page frame and we can
2365 : : * use it directly to store the loaded page.
2366 : : */
2367 : : last_highmem_page = page;
2368 : : return buffer;
2369 : : }
2370 : : /*
2371 : : * The "original" page frame has not been allocated and we have to
2372 : : * use a "safe" page frame to store the loaded page.
2373 : : */
2374 : : pbe = chain_alloc(ca, sizeof(struct highmem_pbe));
2375 : : if (!pbe) {
2376 : : swsusp_free();
2377 : : return ERR_PTR(-ENOMEM);
2378 : : }
2379 : : pbe->orig_page = page;
2380 : : if (safe_highmem_pages > 0) {
2381 : : struct page *tmp;
2382 : :
2383 : : /* Copy of the page will be stored in high memory */
2384 : : kaddr = buffer;
2385 : : tmp = pfn_to_page(memory_bm_next_pfn(safe_highmem_bm));
2386 : : safe_highmem_pages--;
2387 : : last_highmem_page = tmp;
2388 : : pbe->copy_page = tmp;
2389 : : } else {
2390 : : /* Copy of the page will be stored in normal memory */
2391 : : kaddr = safe_pages_list;
2392 : : safe_pages_list = safe_pages_list->next;
2393 : : pbe->copy_page = virt_to_page(kaddr);
2394 : : }
2395 : : pbe->next = highmem_pblist;
2396 : : highmem_pblist = pbe;
2397 : : return kaddr;
2398 : : }
2399 : :
2400 : : /**
2401 : : * copy_last_highmem_page - Copy most the most recent highmem image page.
2402 : : *
2403 : : * Copy the contents of a highmem image from @buffer, where the caller of
2404 : : * snapshot_write_next() has stored them, to the right location represented by
2405 : : * @last_highmem_page .
2406 : : */
2407 : : static void copy_last_highmem_page(void)
2408 : : {
2409 : : if (last_highmem_page) {
2410 : : void *dst;
2411 : :
2412 : : dst = kmap_atomic(last_highmem_page);
2413 : : copy_page(dst, buffer);
2414 : : kunmap_atomic(dst);
2415 : : last_highmem_page = NULL;
2416 : : }
2417 : : }
2418 : :
2419 : : static inline int last_highmem_page_copied(void)
2420 : : {
2421 : : return !last_highmem_page;
2422 : : }
2423 : :
2424 : : static inline void free_highmem_data(void)
2425 : : {
2426 : : if (safe_highmem_bm)
2427 : : memory_bm_free(safe_highmem_bm, PG_UNSAFE_CLEAR);
2428 : :
2429 : : if (buffer)
2430 : : free_image_page(buffer, PG_UNSAFE_CLEAR);
2431 : : }
2432 : : #else
2433 : 0 : static unsigned int count_highmem_image_pages(struct memory_bitmap *bm) { return 0; }
2434 : :
2435 : : static inline int prepare_highmem_image(struct memory_bitmap *bm,
2436 : : unsigned int *nr_highmem_p) { return 0; }
2437 : :
2438 : : static inline void *get_highmem_page_buffer(struct page *page,
2439 : : struct chain_allocator *ca)
2440 : : {
2441 : : return ERR_PTR(-EINVAL);
2442 : : }
2443 : :
2444 : 0 : static inline void copy_last_highmem_page(void) {}
2445 : 0 : static inline int last_highmem_page_copied(void) { return 1; }
2446 : 0 : static inline void free_highmem_data(void) {}
2447 : : #endif /* CONFIG_HIGHMEM */
2448 : :
2449 : : #define PBES_PER_LINKED_PAGE (LINKED_PAGE_DATA_SIZE / sizeof(struct pbe))
2450 : :
2451 : : /**
2452 : : * prepare_image - Make room for loading hibernation image.
2453 : : * @new_bm: Unitialized memory bitmap structure.
2454 : : * @bm: Memory bitmap with unsafe pages marked.
2455 : : *
2456 : : * Use @bm to mark the pages that will be overwritten in the process of
2457 : : * restoring the system memory state from the suspend image ("unsafe" pages)
2458 : : * and allocate memory for the image.
2459 : : *
2460 : : * The idea is to allocate a new memory bitmap first and then allocate
2461 : : * as many pages as needed for image data, but without specifying what those
2462 : : * pages will be used for just yet. Instead, we mark them all as allocated and
2463 : : * create a lists of "safe" pages to be used later. On systems with high
2464 : : * memory a list of "safe" highmem pages is created too.
2465 : : */
2466 : 0 : static int prepare_image(struct memory_bitmap *new_bm, struct memory_bitmap *bm)
2467 : : {
2468 : 0 : unsigned int nr_pages, nr_highmem;
2469 : 0 : struct linked_page *lp;
2470 : 0 : int error;
2471 : :
2472 : : /* If there is no highmem, the buffer will not be necessary */
2473 : 0 : free_image_page(buffer, PG_UNSAFE_CLEAR);
2474 : 0 : buffer = NULL;
2475 : :
2476 : 0 : nr_highmem = count_highmem_image_pages(bm);
2477 : 0 : mark_unsafe_pages(bm);
2478 : :
2479 : 0 : error = memory_bm_create(new_bm, GFP_ATOMIC, PG_SAFE);
2480 [ # # ]: 0 : if (error)
2481 : 0 : goto Free;
2482 : :
2483 : 0 : duplicate_memory_bitmap(new_bm, bm);
2484 : 0 : memory_bm_free(bm, PG_UNSAFE_KEEP);
2485 : 0 : if (nr_highmem > 0) {
2486 : : error = prepare_highmem_image(bm, &nr_highmem);
2487 : : if (error)
2488 : : goto Free;
2489 : : }
2490 : : /*
2491 : : * Reserve some safe pages for potential later use.
2492 : : *
2493 : : * NOTE: This way we make sure there will be enough safe pages for the
2494 : : * chain_alloc() in get_buffer(). It is a bit wasteful, but
2495 : : * nr_copy_pages cannot be greater than 50% of the memory anyway.
2496 : : *
2497 : : * nr_copy_pages cannot be less than allocated_unsafe_pages too.
2498 : : */
2499 : 0 : nr_pages = nr_copy_pages - nr_highmem - allocated_unsafe_pages;
2500 : 0 : nr_pages = DIV_ROUND_UP(nr_pages, PBES_PER_LINKED_PAGE);
2501 [ # # ]: 0 : while (nr_pages > 0) {
2502 : 0 : lp = get_image_page(GFP_ATOMIC, PG_SAFE);
2503 [ # # ]: 0 : if (!lp) {
2504 : 0 : error = -ENOMEM;
2505 : 0 : goto Free;
2506 : : }
2507 : 0 : lp->next = safe_pages_list;
2508 : 0 : safe_pages_list = lp;
2509 : 0 : nr_pages--;
2510 : : }
2511 : : /* Preallocate memory for the image */
2512 : 0 : nr_pages = nr_copy_pages - nr_highmem - allocated_unsafe_pages;
2513 [ # # ]: 0 : while (nr_pages > 0) {
2514 : 0 : lp = (struct linked_page *)get_zeroed_page(GFP_ATOMIC);
2515 [ # # ]: 0 : if (!lp) {
2516 : 0 : error = -ENOMEM;
2517 : 0 : goto Free;
2518 : : }
2519 [ # # # # : 0 : if (!swsusp_page_is_free(virt_to_page(lp))) {
# # ]
2520 : : /* The page is "safe", add it to the list */
2521 : 0 : lp->next = safe_pages_list;
2522 : 0 : safe_pages_list = lp;
2523 : : }
2524 : : /* Mark the page as allocated */
2525 [ # # # # ]: 0 : swsusp_set_page_forbidden(virt_to_page(lp));
2526 [ # # # # ]: 0 : swsusp_set_page_free(virt_to_page(lp));
2527 : 0 : nr_pages--;
2528 : : }
2529 : : return 0;
2530 : :
2531 : 0 : Free:
2532 : 0 : swsusp_free();
2533 : 0 : return error;
2534 : : }
2535 : :
2536 : : /**
2537 : : * get_buffer - Get the address to store the next image data page.
2538 : : *
2539 : : * Get the address that snapshot_write_next() should return to its caller to
2540 : : * write to.
2541 : : */
2542 : 0 : static void *get_buffer(struct memory_bitmap *bm, struct chain_allocator *ca)
2543 : : {
2544 : 0 : struct pbe *pbe;
2545 : 0 : struct page *page;
2546 : 0 : unsigned long pfn = memory_bm_next_pfn(bm);
2547 : :
2548 [ # # ]: 0 : if (pfn == BM_END_OF_MAP)
2549 : : return ERR_PTR(-EFAULT);
2550 : :
2551 : 0 : page = pfn_to_page(pfn);
2552 [ # # ]: 0 : if (PageHighMem(page))
2553 : : return get_highmem_page_buffer(page, ca);
2554 : :
2555 [ # # # # : 0 : if (swsusp_page_is_forbidden(page) && swsusp_page_is_free(page))
# # ]
2556 : : /*
2557 : : * We have allocated the "original" page frame and we can
2558 : : * use it directly to store the loaded page.
2559 : : */
2560 : 0 : return page_address(page);
2561 : :
2562 : : /*
2563 : : * The "original" page frame has not been allocated and we have to
2564 : : * use a "safe" page frame to store the loaded page.
2565 : : */
2566 : 0 : pbe = chain_alloc(ca, sizeof(struct pbe));
2567 [ # # ]: 0 : if (!pbe) {
2568 : 0 : swsusp_free();
2569 : 0 : return ERR_PTR(-ENOMEM);
2570 : : }
2571 : 0 : pbe->orig_address = page_address(page);
2572 : 0 : pbe->address = safe_pages_list;
2573 : 0 : safe_pages_list = safe_pages_list->next;
2574 : 0 : pbe->next = restore_pblist;
2575 : 0 : restore_pblist = pbe;
2576 : 0 : return pbe->address;
2577 : : }
2578 : :
2579 : : /**
2580 : : * snapshot_write_next - Get the address to store the next image page.
2581 : : * @handle: Snapshot handle structure to guide the writing.
2582 : : *
2583 : : * On the first call, @handle should point to a zeroed snapshot_handle
2584 : : * structure. The structure gets populated then and a pointer to it should be
2585 : : * passed to this function every next time.
2586 : : *
2587 : : * On success, the function returns a positive number. Then, the caller
2588 : : * is allowed to write up to the returned number of bytes to the memory
2589 : : * location computed by the data_of() macro.
2590 : : *
2591 : : * The function returns 0 to indicate the "end of file" condition. Negative
2592 : : * numbers are returned on errors, in which cases the structure pointed to by
2593 : : * @handle is not updated and should not be used any more.
2594 : : */
2595 : 0 : int snapshot_write_next(struct snapshot_handle *handle)
2596 : : {
2597 : 0 : static struct chain_allocator ca;
2598 : 0 : int error = 0;
2599 : :
2600 : : /* Check if we have already loaded the entire image */
2601 [ # # # # ]: 0 : if (handle->cur > 1 && handle->cur > nr_meta_pages + nr_copy_pages)
2602 : : return 0;
2603 : :
2604 : 0 : handle->sync_read = 1;
2605 : :
2606 [ # # ]: 0 : if (!handle->cur) {
2607 [ # # ]: 0 : if (!buffer)
2608 : : /* This makes the buffer be freed by swsusp_free() */
2609 : 0 : buffer = get_image_page(GFP_ATOMIC, PG_ANY);
2610 : :
2611 [ # # ]: 0 : if (!buffer)
2612 : : return -ENOMEM;
2613 : :
2614 : 0 : handle->buffer = buffer;
2615 [ # # ]: 0 : } else if (handle->cur == 1) {
2616 : 0 : error = load_header(buffer);
2617 [ # # ]: 0 : if (error)
2618 : : return error;
2619 : :
2620 : 0 : safe_pages_list = NULL;
2621 : :
2622 : 0 : error = memory_bm_create(©_bm, GFP_ATOMIC, PG_ANY);
2623 [ # # ]: 0 : if (error)
2624 : : return error;
2625 : :
2626 : : /* Allocate buffer for page keys. */
2627 : 0 : error = page_key_alloc(nr_copy_pages);
2628 : 0 : if (error)
2629 : : return error;
2630 : :
2631 : 0 : hibernate_restore_protection_begin();
2632 [ # # ]: 0 : } else if (handle->cur <= nr_meta_pages + 1) {
2633 : 0 : error = unpack_orig_pfns(buffer, ©_bm);
2634 [ # # ]: 0 : if (error)
2635 : : return error;
2636 : :
2637 [ # # ]: 0 : if (handle->cur == nr_meta_pages + 1) {
2638 : 0 : error = prepare_image(&orig_bm, ©_bm);
2639 [ # # ]: 0 : if (error)
2640 : : return error;
2641 : :
2642 : 0 : chain_init(&ca, GFP_ATOMIC, PG_SAFE);
2643 : 0 : memory_bm_position_reset(&orig_bm);
2644 : 0 : restore_pblist = NULL;
2645 : 0 : handle->buffer = get_buffer(&orig_bm, &ca);
2646 : 0 : handle->sync_read = 0;
2647 [ # # ]: 0 : if (IS_ERR(handle->buffer))
2648 : 0 : return PTR_ERR(handle->buffer);
2649 : : }
2650 : : } else {
2651 : 0 : copy_last_highmem_page();
2652 : : /* Restore page key for data page (s390 only). */
2653 [ # # ]: 0 : page_key_write(handle->buffer);
2654 [ # # ]: 0 : hibernate_restore_protect_page(handle->buffer);
2655 : 0 : handle->buffer = get_buffer(&orig_bm, &ca);
2656 [ # # ]: 0 : if (IS_ERR(handle->buffer))
2657 : 0 : return PTR_ERR(handle->buffer);
2658 [ # # ]: 0 : if (handle->buffer != buffer)
2659 : 0 : handle->sync_read = 0;
2660 : : }
2661 : 0 : handle->cur++;
2662 : 0 : return PAGE_SIZE;
2663 : : }
2664 : :
2665 : : /**
2666 : : * snapshot_write_finalize - Complete the loading of a hibernation image.
2667 : : *
2668 : : * Must be called after the last call to snapshot_write_next() in case the last
2669 : : * page in the image happens to be a highmem page and its contents should be
2670 : : * stored in highmem. Additionally, it recycles bitmap memory that's not
2671 : : * necessary any more.
2672 : : */
2673 : 0 : void snapshot_write_finalize(struct snapshot_handle *handle)
2674 : : {
2675 : 0 : copy_last_highmem_page();
2676 : : /* Restore page key for data page (s390 only). */
2677 [ # # ]: 0 : page_key_write(handle->buffer);
2678 [ # # ]: 0 : page_key_free();
2679 [ # # ]: 0 : hibernate_restore_protect_page(handle->buffer);
2680 : : /* Do that only if we have loaded the image entirely */
2681 [ # # # # ]: 0 : if (handle->cur > 1 && handle->cur > nr_meta_pages + nr_copy_pages) {
2682 : 0 : memory_bm_recycle(&orig_bm);
2683 : 0 : free_highmem_data();
2684 : : }
2685 : 0 : }
2686 : :
2687 : 0 : int snapshot_image_loaded(struct snapshot_handle *handle)
2688 : : {
2689 [ # # ]: 0 : return !(!nr_copy_pages || !last_highmem_page_copied() ||
2690 [ # # ]: 0 : handle->cur <= nr_meta_pages + nr_copy_pages);
2691 : : }
2692 : :
2693 : : #ifdef CONFIG_HIGHMEM
2694 : : /* Assumes that @buf is ready and points to a "safe" page */
2695 : : static inline void swap_two_pages_data(struct page *p1, struct page *p2,
2696 : : void *buf)
2697 : : {
2698 : : void *kaddr1, *kaddr2;
2699 : :
2700 : : kaddr1 = kmap_atomic(p1);
2701 : : kaddr2 = kmap_atomic(p2);
2702 : : copy_page(buf, kaddr1);
2703 : : copy_page(kaddr1, kaddr2);
2704 : : copy_page(kaddr2, buf);
2705 : : kunmap_atomic(kaddr2);
2706 : : kunmap_atomic(kaddr1);
2707 : : }
2708 : :
2709 : : /**
2710 : : * restore_highmem - Put highmem image pages into their original locations.
2711 : : *
2712 : : * For each highmem page that was in use before hibernation and is included in
2713 : : * the image, and also has been allocated by the "restore" kernel, swap its
2714 : : * current contents with the previous (ie. "before hibernation") ones.
2715 : : *
2716 : : * If the restore eventually fails, we can call this function once again and
2717 : : * restore the highmem state as seen by the restore kernel.
2718 : : */
2719 : : int restore_highmem(void)
2720 : : {
2721 : : struct highmem_pbe *pbe = highmem_pblist;
2722 : : void *buf;
2723 : :
2724 : : if (!pbe)
2725 : : return 0;
2726 : :
2727 : : buf = get_image_page(GFP_ATOMIC, PG_SAFE);
2728 : : if (!buf)
2729 : : return -ENOMEM;
2730 : :
2731 : : while (pbe) {
2732 : : swap_two_pages_data(pbe->copy_page, pbe->orig_page, buf);
2733 : : pbe = pbe->next;
2734 : : }
2735 : : free_image_page(buf, PG_UNSAFE_CLEAR);
2736 : : return 0;
2737 : : }
2738 : : #endif /* CONFIG_HIGHMEM */
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