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-rw-r--r--kernel/power/Makefile2
-rw-r--r--kernel/power/power.h31
-rw-r--r--kernel/power/swap.c544
-rw-r--r--kernel/power/swsusp.c568
4 files changed, 581 insertions, 564 deletions
diff --git a/kernel/power/Makefile b/kernel/power/Makefile
index 04be7d0d96a7..bb91a0615303 100644
--- a/kernel/power/Makefile
+++ b/kernel/power/Makefile
@@ -5,7 +5,7 @@ endif
5 5
6obj-y := main.o process.o console.o 6obj-y := main.o process.o console.o
7obj-$(CONFIG_PM_LEGACY) += pm.o 7obj-$(CONFIG_PM_LEGACY) += pm.o
8obj-$(CONFIG_SOFTWARE_SUSPEND) += swsusp.o disk.o snapshot.o 8obj-$(CONFIG_SOFTWARE_SUSPEND) += swsusp.o disk.o snapshot.o swap.o
9 9
10obj-$(CONFIG_SUSPEND_SMP) += smp.o 10obj-$(CONFIG_SUSPEND_SMP) += smp.o
11 11
diff --git a/kernel/power/power.h b/kernel/power/power.h
index ea7132ed029b..089c84bed895 100644
--- a/kernel/power/power.h
+++ b/kernel/power/power.h
@@ -41,8 +41,8 @@ extern struct pbe *pagedir_nosave;
41 41
42/* Preferred image size in bytes (default 500 MB) */ 42/* Preferred image size in bytes (default 500 MB) */
43extern unsigned long image_size; 43extern unsigned long image_size;
44
45extern int in_suspend; 44extern int in_suspend;
45extern dev_t swsusp_resume_device;
46 46
47extern asmlinkage int swsusp_arch_suspend(void); 47extern asmlinkage int swsusp_arch_suspend(void);
48extern asmlinkage int swsusp_arch_resume(void); 48extern asmlinkage int swsusp_arch_resume(void);
@@ -65,3 +65,32 @@ struct snapshot_handle {
65extern int snapshot_read_next(struct snapshot_handle *handle, size_t count); 65extern int snapshot_read_next(struct snapshot_handle *handle, size_t count);
66extern int snapshot_write_next(struct snapshot_handle *handle, size_t count); 66extern int snapshot_write_next(struct snapshot_handle *handle, size_t count);
67int snapshot_image_loaded(struct snapshot_handle *handle); 67int snapshot_image_loaded(struct snapshot_handle *handle);
68
69/**
70 * The bitmap is used for tracing allocated swap pages
71 *
72 * The entire bitmap consists of a number of bitmap_page
73 * structures linked with the help of the .next member.
74 * Thus each page can be allocated individually, so we only
75 * need to make 0-order memory allocations to create
76 * the bitmap.
77 */
78
79#define BITMAP_PAGE_SIZE (PAGE_SIZE - sizeof(void *))
80#define BITMAP_PAGE_CHUNKS (BITMAP_PAGE_SIZE / sizeof(long))
81#define BITS_PER_CHUNK (sizeof(long) * 8)
82#define BITMAP_PAGE_BITS (BITMAP_PAGE_CHUNKS * BITS_PER_CHUNK)
83
84struct bitmap_page {
85 unsigned long chunks[BITMAP_PAGE_CHUNKS];
86 struct bitmap_page *next;
87};
88
89extern void free_bitmap(struct bitmap_page *bitmap);
90extern struct bitmap_page *alloc_bitmap(unsigned int nr_bits);
91extern unsigned long alloc_swap_page(int swap, struct bitmap_page *bitmap);
92extern void free_all_swap_pages(int swap, struct bitmap_page *bitmap);
93
94extern int swsusp_shrink_memory(void);
95extern int swsusp_suspend(void);
96extern int swsusp_resume(void);
diff --git a/kernel/power/swap.c b/kernel/power/swap.c
new file mode 100644
index 000000000000..9177f3f73a6c
--- /dev/null
+++ b/kernel/power/swap.c
@@ -0,0 +1,544 @@
1/*
2 * linux/kernel/power/swap.c
3 *
4 * This file provides functions for reading the suspend image from
5 * and writing it to a swap partition.
6 *
7 * Copyright (C) 1998,2001-2005 Pavel Machek <pavel@suse.cz>
8 * Copyright (C) 2006 Rafael J. Wysocki <rjw@sisk.pl>
9 *
10 * This file is released under the GPLv2.
11 *
12 */
13
14#include <linux/module.h>
15#include <linux/smp_lock.h>
16#include <linux/file.h>
17#include <linux/utsname.h>
18#include <linux/version.h>
19#include <linux/delay.h>
20#include <linux/bitops.h>
21#include <linux/genhd.h>
22#include <linux/device.h>
23#include <linux/buffer_head.h>
24#include <linux/bio.h>
25#include <linux/swap.h>
26#include <linux/swapops.h>
27#include <linux/pm.h>
28
29#include "power.h"
30
31extern char resume_file[];
32
33#define SWSUSP_SIG "S1SUSPEND"
34
35static struct swsusp_header {
36 char reserved[PAGE_SIZE - 20 - sizeof(swp_entry_t)];
37 swp_entry_t image;
38 char orig_sig[10];
39 char sig[10];
40} __attribute__((packed, aligned(PAGE_SIZE))) swsusp_header;
41
42/*
43 * Saving part...
44 */
45
46static unsigned short root_swap = 0xffff;
47
48static int mark_swapfiles(swp_entry_t start)
49{
50 int error;
51
52 rw_swap_page_sync(READ,
53 swp_entry(root_swap, 0),
54 virt_to_page((unsigned long)&swsusp_header));
55 if (!memcmp("SWAP-SPACE",swsusp_header.sig, 10) ||
56 !memcmp("SWAPSPACE2",swsusp_header.sig, 10)) {
57 memcpy(swsusp_header.orig_sig,swsusp_header.sig, 10);
58 memcpy(swsusp_header.sig,SWSUSP_SIG, 10);
59 swsusp_header.image = start;
60 error = rw_swap_page_sync(WRITE,
61 swp_entry(root_swap, 0),
62 virt_to_page((unsigned long)
63 &swsusp_header));
64 } else {
65 pr_debug("swsusp: Partition is not swap space.\n");
66 error = -ENODEV;
67 }
68 return error;
69}
70
71/**
72 * swsusp_swap_check - check if the resume device is a swap device
73 * and get its index (if so)
74 */
75
76static int swsusp_swap_check(void) /* This is called before saving image */
77{
78 int res = swap_type_of(swsusp_resume_device);
79
80 if (res >= 0) {
81 root_swap = res;
82 return 0;
83 }
84 return res;
85}
86
87/**
88 * write_page - Write one page to given swap location.
89 * @buf: Address we're writing.
90 * @offset: Offset of the swap page we're writing to.
91 */
92
93static int write_page(void *buf, unsigned long offset)
94{
95 swp_entry_t entry;
96 int error = -ENOSPC;
97
98 if (offset) {
99 entry = swp_entry(root_swap, offset);
100 error = rw_swap_page_sync(WRITE, entry, virt_to_page(buf));
101 }
102 return error;
103}
104
105/*
106 * The swap map is a data structure used for keeping track of each page
107 * written to a swap partition. It consists of many swap_map_page
108 * structures that contain each an array of MAP_PAGE_SIZE swap entries.
109 * These structures are stored on the swap and linked together with the
110 * help of the .next_swap member.
111 *
112 * The swap map is created during suspend. The swap map pages are
113 * allocated and populated one at a time, so we only need one memory
114 * page to set up the entire structure.
115 *
116 * During resume we also only need to use one swap_map_page structure
117 * at a time.
118 */
119
120#define MAP_PAGE_ENTRIES (PAGE_SIZE / sizeof(long) - 1)
121
122struct swap_map_page {
123 unsigned long entries[MAP_PAGE_ENTRIES];
124 unsigned long next_swap;
125};
126
127/**
128 * The swap_map_handle structure is used for handling swap in
129 * a file-alike way
130 */
131
132struct swap_map_handle {
133 struct swap_map_page *cur;
134 unsigned long cur_swap;
135 struct bitmap_page *bitmap;
136 unsigned int k;
137};
138
139static void release_swap_writer(struct swap_map_handle *handle)
140{
141 if (handle->cur)
142 free_page((unsigned long)handle->cur);
143 handle->cur = NULL;
144 if (handle->bitmap)
145 free_bitmap(handle->bitmap);
146 handle->bitmap = NULL;
147}
148
149static int get_swap_writer(struct swap_map_handle *handle)
150{
151 handle->cur = (struct swap_map_page *)get_zeroed_page(GFP_KERNEL);
152 if (!handle->cur)
153 return -ENOMEM;
154 handle->bitmap = alloc_bitmap(count_swap_pages(root_swap, 0));
155 if (!handle->bitmap) {
156 release_swap_writer(handle);
157 return -ENOMEM;
158 }
159 handle->cur_swap = alloc_swap_page(root_swap, handle->bitmap);
160 if (!handle->cur_swap) {
161 release_swap_writer(handle);
162 return -ENOSPC;
163 }
164 handle->k = 0;
165 return 0;
166}
167
168static int swap_write_page(struct swap_map_handle *handle, void *buf)
169{
170 int error;
171 unsigned long offset;
172
173 if (!handle->cur)
174 return -EINVAL;
175 offset = alloc_swap_page(root_swap, handle->bitmap);
176 error = write_page(buf, offset);
177 if (error)
178 return error;
179 handle->cur->entries[handle->k++] = offset;
180 if (handle->k >= MAP_PAGE_ENTRIES) {
181 offset = alloc_swap_page(root_swap, handle->bitmap);
182 if (!offset)
183 return -ENOSPC;
184 handle->cur->next_swap = offset;
185 error = write_page(handle->cur, handle->cur_swap);
186 if (error)
187 return error;
188 memset(handle->cur, 0, PAGE_SIZE);
189 handle->cur_swap = offset;
190 handle->k = 0;
191 }
192 return 0;
193}
194
195static int flush_swap_writer(struct swap_map_handle *handle)
196{
197 if (handle->cur && handle->cur_swap)
198 return write_page(handle->cur, handle->cur_swap);
199 else
200 return -EINVAL;
201}
202
203/**
204 * save_image - save the suspend image data
205 */
206
207static int save_image(struct swap_map_handle *handle,
208 struct snapshot_handle *snapshot,
209 unsigned int nr_pages)
210{
211 unsigned int m;
212 int ret;
213 int error = 0;
214
215 printk("Saving image data pages (%u pages) ... ", nr_pages);
216 m = nr_pages / 100;
217 if (!m)
218 m = 1;
219 nr_pages = 0;
220 do {
221 ret = snapshot_read_next(snapshot, PAGE_SIZE);
222 if (ret > 0) {
223 error = swap_write_page(handle, data_of(*snapshot));
224 if (error)
225 break;
226 if (!(nr_pages % m))
227 printk("\b\b\b\b%3d%%", nr_pages / m);
228 nr_pages++;
229 }
230 } while (ret > 0);
231 if (!error)
232 printk("\b\b\b\bdone\n");
233 return error;
234}
235
236/**
237 * enough_swap - Make sure we have enough swap to save the image.
238 *
239 * Returns TRUE or FALSE after checking the total amount of swap
240 * space avaiable from the resume partition.
241 */
242
243static int enough_swap(unsigned int nr_pages)
244{
245 unsigned int free_swap = count_swap_pages(root_swap, 1);
246
247 pr_debug("swsusp: free swap pages: %u\n", free_swap);
248 return free_swap > (nr_pages + PAGES_FOR_IO +
249 (nr_pages + PBES_PER_PAGE - 1) / PBES_PER_PAGE);
250}
251
252/**
253 * swsusp_write - Write entire image and metadata.
254 *
255 * It is important _NOT_ to umount filesystems at this point. We want
256 * them synced (in case something goes wrong) but we DO not want to mark
257 * filesystem clean: it is not. (And it does not matter, if we resume
258 * correctly, we'll mark system clean, anyway.)
259 */
260
261int swsusp_write(void)
262{
263 struct swap_map_handle handle;
264 struct snapshot_handle snapshot;
265 struct swsusp_info *header;
266 unsigned long start;
267 int error;
268
269 if ((error = swsusp_swap_check())) {
270 printk(KERN_ERR "swsusp: Cannot find swap device, try swapon -a.\n");
271 return error;
272 }
273 memset(&snapshot, 0, sizeof(struct snapshot_handle));
274 error = snapshot_read_next(&snapshot, PAGE_SIZE);
275 if (error < PAGE_SIZE)
276 return error < 0 ? error : -EFAULT;
277 header = (struct swsusp_info *)data_of(snapshot);
278 if (!enough_swap(header->pages)) {
279 printk(KERN_ERR "swsusp: Not enough free swap\n");
280 return -ENOSPC;
281 }
282 error = get_swap_writer(&handle);
283 if (!error) {
284 start = handle.cur_swap;
285 error = swap_write_page(&handle, header);
286 }
287 if (!error)
288 error = save_image(&handle, &snapshot, header->pages - 1);
289 if (!error) {
290 flush_swap_writer(&handle);
291 printk("S");
292 error = mark_swapfiles(swp_entry(root_swap, start));
293 printk("|\n");
294 }
295 if (error)
296 free_all_swap_pages(root_swap, handle.bitmap);
297 release_swap_writer(&handle);
298 return error;
299}
300
301/*
302 * Using bio to read from swap.
303 * This code requires a bit more work than just using buffer heads
304 * but, it is the recommended way for 2.5/2.6.
305 * The following are to signal the beginning and end of I/O. Bios
306 * finish asynchronously, while we want them to happen synchronously.
307 * A simple atomic_t, and a wait loop take care of this problem.
308 */
309
310static atomic_t io_done = ATOMIC_INIT(0);
311
312static int end_io(struct bio *bio, unsigned int num, int err)
313{
314 if (!test_bit(BIO_UPTODATE, &bio->bi_flags))
315 panic("I/O error reading memory image");
316 atomic_set(&io_done, 0);
317 return 0;
318}
319
320static struct block_device *resume_bdev;
321
322/**
323 * submit - submit BIO request.
324 * @rw: READ or WRITE.
325 * @off physical offset of page.
326 * @page: page we're reading or writing.
327 *
328 * Straight from the textbook - allocate and initialize the bio.
329 * If we're writing, make sure the page is marked as dirty.
330 * Then submit it and wait.
331 */
332
333static int submit(int rw, pgoff_t page_off, void *page)
334{
335 int error = 0;
336 struct bio *bio;
337
338 bio = bio_alloc(GFP_ATOMIC, 1);
339 if (!bio)
340 return -ENOMEM;
341 bio->bi_sector = page_off * (PAGE_SIZE >> 9);
342 bio->bi_bdev = resume_bdev;
343 bio->bi_end_io = end_io;
344
345 if (bio_add_page(bio, virt_to_page(page), PAGE_SIZE, 0) < PAGE_SIZE) {
346 printk("swsusp: ERROR: adding page to bio at %ld\n",page_off);
347 error = -EFAULT;
348 goto Done;
349 }
350
351 atomic_set(&io_done, 1);
352 submit_bio(rw | (1 << BIO_RW_SYNC), bio);
353 while (atomic_read(&io_done))
354 yield();
355 if (rw == READ)
356 bio_set_pages_dirty(bio);
357 Done:
358 bio_put(bio);
359 return error;
360}
361
362static int bio_read_page(pgoff_t page_off, void *page)
363{
364 return submit(READ, page_off, page);
365}
366
367static int bio_write_page(pgoff_t page_off, void *page)
368{
369 return submit(WRITE, page_off, page);
370}
371
372/**
373 * The following functions allow us to read data using a swap map
374 * in a file-alike way
375 */
376
377static void release_swap_reader(struct swap_map_handle *handle)
378{
379 if (handle->cur)
380 free_page((unsigned long)handle->cur);
381 handle->cur = NULL;
382}
383
384static int get_swap_reader(struct swap_map_handle *handle,
385 swp_entry_t start)
386{
387 int error;
388
389 if (!swp_offset(start))
390 return -EINVAL;
391 handle->cur = (struct swap_map_page *)get_zeroed_page(GFP_ATOMIC);
392 if (!handle->cur)
393 return -ENOMEM;
394 error = bio_read_page(swp_offset(start), handle->cur);
395 if (error) {
396 release_swap_reader(handle);
397 return error;
398 }
399 handle->k = 0;
400 return 0;
401}
402
403static int swap_read_page(struct swap_map_handle *handle, void *buf)
404{
405 unsigned long offset;
406 int error;
407
408 if (!handle->cur)
409 return -EINVAL;
410 offset = handle->cur->entries[handle->k];
411 if (!offset)
412 return -EFAULT;
413 error = bio_read_page(offset, buf);
414 if (error)
415 return error;
416 if (++handle->k >= MAP_PAGE_ENTRIES) {
417 handle->k = 0;
418 offset = handle->cur->next_swap;
419 if (!offset)
420 release_swap_reader(handle);
421 else
422 error = bio_read_page(offset, handle->cur);
423 }
424 return error;
425}
426
427/**
428 * load_image - load the image using the swap map handle
429 * @handle and the snapshot handle @snapshot
430 * (assume there are @nr_pages pages to load)
431 */
432
433static int load_image(struct swap_map_handle *handle,
434 struct snapshot_handle *snapshot,
435 unsigned int nr_pages)
436{
437 unsigned int m;
438 int ret;
439 int error = 0;
440
441 printk("Loading image data pages (%u pages) ... ", nr_pages);
442 m = nr_pages / 100;
443 if (!m)
444 m = 1;
445 nr_pages = 0;
446 do {
447 ret = snapshot_write_next(snapshot, PAGE_SIZE);
448 if (ret > 0) {
449 error = swap_read_page(handle, data_of(*snapshot));
450 if (error)
451 break;
452 if (!(nr_pages % m))
453 printk("\b\b\b\b%3d%%", nr_pages / m);
454 nr_pages++;
455 }
456 } while (ret > 0);
457 if (!error)
458 printk("\b\b\b\bdone\n");
459 if (!snapshot_image_loaded(snapshot))
460 error = -ENODATA;
461 return error;
462}
463
464int swsusp_read(void)
465{
466 int error;
467 struct swap_map_handle handle;
468 struct snapshot_handle snapshot;
469 struct swsusp_info *header;
470
471 if (IS_ERR(resume_bdev)) {
472 pr_debug("swsusp: block device not initialised\n");
473 return PTR_ERR(resume_bdev);
474 }
475
476 memset(&snapshot, 0, sizeof(struct snapshot_handle));
477 error = snapshot_write_next(&snapshot, PAGE_SIZE);
478 if (error < PAGE_SIZE)
479 return error < 0 ? error : -EFAULT;
480 header = (struct swsusp_info *)data_of(snapshot);
481 error = get_swap_reader(&handle, swsusp_header.image);
482 if (!error)
483 error = swap_read_page(&handle, header);
484 if (!error)
485 error = load_image(&handle, &snapshot, header->pages - 1);
486 release_swap_reader(&handle);
487
488 blkdev_put(resume_bdev);
489
490 if (!error)
491 pr_debug("swsusp: Reading resume file was successful\n");
492 else
493 pr_debug("swsusp: Error %d resuming\n", error);
494 return error;
495}
496
497/**
498 * swsusp_check - Check for swsusp signature in the resume device
499 */
500
501int swsusp_check(void)
502{
503 int error;
504
505 resume_bdev = open_by_devnum(swsusp_resume_device, FMODE_READ);
506 if (!IS_ERR(resume_bdev)) {
507 set_blocksize(resume_bdev, PAGE_SIZE);
508 memset(&swsusp_header, 0, sizeof(swsusp_header));
509 if ((error = bio_read_page(0, &swsusp_header)))
510 return error;
511 if (!memcmp(SWSUSP_SIG, swsusp_header.sig, 10)) {
512 memcpy(swsusp_header.sig, swsusp_header.orig_sig, 10);
513 /* Reset swap signature now */
514 error = bio_write_page(0, &swsusp_header);
515 } else {
516 return -EINVAL;
517 }
518 if (error)
519 blkdev_put(resume_bdev);
520 else
521 pr_debug("swsusp: Signature found, resuming\n");
522 } else {
523 error = PTR_ERR(resume_bdev);
524 }
525
526 if (error)
527 pr_debug("swsusp: Error %d check for resume file\n", error);
528
529 return error;
530}
531
532/**
533 * swsusp_close - close swap device.
534 */
535
536void swsusp_close(void)
537{
538 if (IS_ERR(resume_bdev)) {
539 pr_debug("swsusp: block device not initialised\n");
540 return;
541 }
542
543 blkdev_put(resume_bdev);
544}
diff --git a/kernel/power/swsusp.c b/kernel/power/swsusp.c
index 457084f50010..c4016cbbd3e0 100644
--- a/kernel/power/swsusp.c
+++ b/kernel/power/swsusp.c
@@ -31,41 +31,24 @@
31 * Fixed runaway init 31 * Fixed runaway init
32 * 32 *
33 * Rafael J. Wysocki <rjw@sisk.pl> 33 * Rafael J. Wysocki <rjw@sisk.pl>
34 * Added the swap map data structure and reworked the handling of swap 34 * Reworked the freeing of memory and the handling of swap
35 * 35 *
36 * More state savers are welcome. Especially for the scsi layer... 36 * More state savers are welcome. Especially for the scsi layer...
37 * 37 *
38 * For TODOs,FIXMEs also look in Documentation/power/swsusp.txt 38 * For TODOs,FIXMEs also look in Documentation/power/swsusp.txt
39 */ 39 */
40 40
41#include <linux/module.h>
42#include <linux/mm.h> 41#include <linux/mm.h>
43#include <linux/suspend.h> 42#include <linux/suspend.h>
44#include <linux/smp_lock.h>
45#include <linux/file.h>
46#include <linux/utsname.h>
47#include <linux/version.h>
48#include <linux/delay.h>
49#include <linux/bitops.h>
50#include <linux/spinlock.h> 43#include <linux/spinlock.h>
51#include <linux/genhd.h>
52#include <linux/kernel.h> 44#include <linux/kernel.h>
53#include <linux/major.h> 45#include <linux/major.h>
54#include <linux/swap.h> 46#include <linux/swap.h>
55#include <linux/pm.h> 47#include <linux/pm.h>
56#include <linux/device.h>
57#include <linux/buffer_head.h>
58#include <linux/swapops.h> 48#include <linux/swapops.h>
59#include <linux/bootmem.h> 49#include <linux/bootmem.h>
60#include <linux/syscalls.h> 50#include <linux/syscalls.h>
61#include <linux/highmem.h> 51#include <linux/highmem.h>
62#include <linux/bio.h>
63
64#include <asm/uaccess.h>
65#include <asm/mmu_context.h>
66#include <asm/pgtable.h>
67#include <asm/tlbflush.h>
68#include <asm/io.h>
69 52
70#include "power.h" 53#include "power.h"
71 54
@@ -89,91 +72,15 @@ static int restore_highmem(void) { return 0; }
89static unsigned int count_highmem_pages(void) { return 0; } 72static unsigned int count_highmem_pages(void) { return 0; }
90#endif 73#endif
91 74
92extern char resume_file[];
93
94#define SWSUSP_SIG "S1SUSPEND"
95
96static struct swsusp_header {
97 char reserved[PAGE_SIZE - 20 - sizeof(swp_entry_t)];
98 swp_entry_t image;
99 char orig_sig[10];
100 char sig[10];
101} __attribute__((packed, aligned(PAGE_SIZE))) swsusp_header;
102
103/*
104 * Saving part...
105 */
106
107static unsigned short root_swap = 0xffff;
108
109static int mark_swapfiles(swp_entry_t start)
110{
111 int error;
112
113 rw_swap_page_sync(READ,
114 swp_entry(root_swap, 0),
115 virt_to_page((unsigned long)&swsusp_header));
116 if (!memcmp("SWAP-SPACE",swsusp_header.sig, 10) ||
117 !memcmp("SWAPSPACE2",swsusp_header.sig, 10)) {
118 memcpy(swsusp_header.orig_sig,swsusp_header.sig, 10);
119 memcpy(swsusp_header.sig,SWSUSP_SIG, 10);
120 swsusp_header.image = start;
121 error = rw_swap_page_sync(WRITE,
122 swp_entry(root_swap, 0),
123 virt_to_page((unsigned long)
124 &swsusp_header));
125 } else {
126 pr_debug("swsusp: Partition is not swap space.\n");
127 error = -ENODEV;
128 }
129 return error;
130}
131
132/**
133 * swsusp_swap_check - check if the resume device is a swap device
134 * and get its index (if so)
135 */
136
137static int swsusp_swap_check(void) /* This is called before saving image */
138{
139 int res = swap_type_of(swsusp_resume_device);
140
141 if (res >= 0) {
142 root_swap = res;
143 return 0;
144 }
145 return res;
146}
147
148/**
149 * The bitmap is used for tracing allocated swap pages
150 *
151 * The entire bitmap consists of a number of bitmap_page
152 * structures linked with the help of the .next member.
153 * Thus each page can be allocated individually, so we only
154 * need to make 0-order memory allocations to create
155 * the bitmap.
156 */
157
158#define BITMAP_PAGE_SIZE (PAGE_SIZE - sizeof(void *))
159#define BITMAP_PAGE_CHUNKS (BITMAP_PAGE_SIZE / sizeof(long))
160#define BITS_PER_CHUNK (sizeof(long) * 8)
161#define BITMAP_PAGE_BITS (BITMAP_PAGE_CHUNKS * BITS_PER_CHUNK)
162
163struct bitmap_page {
164 unsigned long chunks[BITMAP_PAGE_CHUNKS];
165 struct bitmap_page *next;
166};
167
168/** 75/**
169 * The following functions are used for tracing the allocated 76 * The following functions are used for tracing the allocated
170 * swap pages, so that they can be freed in case of an error. 77 * swap pages, so that they can be freed in case of an error.
171 * 78 *
172 * The functions operate on a linked bitmap structure defined 79 * The functions operate on a linked bitmap structure defined
173 * above 80 * in power.h
174 */ 81 */
175 82
176static void free_bitmap(struct bitmap_page *bitmap) 83void free_bitmap(struct bitmap_page *bitmap)
177{ 84{
178 struct bitmap_page *bp; 85 struct bitmap_page *bp;
179 86
@@ -184,7 +91,7 @@ static void free_bitmap(struct bitmap_page *bitmap)
184 } 91 }
185} 92}
186 93
187static struct bitmap_page *alloc_bitmap(unsigned int nr_bits) 94struct bitmap_page *alloc_bitmap(unsigned int nr_bits)
188{ 95{
189 struct bitmap_page *bitmap, *bp; 96 struct bitmap_page *bitmap, *bp;
190 unsigned int n; 97 unsigned int n;
@@ -227,7 +134,7 @@ static int bitmap_set(struct bitmap_page *bitmap, unsigned long bit)
227 return 0; 134 return 0;
228} 135}
229 136
230static unsigned long alloc_swap_page(int swap, struct bitmap_page *bitmap) 137unsigned long alloc_swap_page(int swap, struct bitmap_page *bitmap)
231{ 138{
232 unsigned long offset; 139 unsigned long offset;
233 140
@@ -241,7 +148,7 @@ static unsigned long alloc_swap_page(int swap, struct bitmap_page *bitmap)
241 return offset; 148 return offset;
242} 149}
243 150
244static void free_all_swap_pages(int swap, struct bitmap_page *bitmap) 151void free_all_swap_pages(int swap, struct bitmap_page *bitmap)
245{ 152{
246 unsigned int bit, n; 153 unsigned int bit, n;
247 unsigned long test; 154 unsigned long test;
@@ -259,220 +166,6 @@ static void free_all_swap_pages(int swap, struct bitmap_page *bitmap)
259} 166}
260 167
261/** 168/**
262 * write_page - Write one page to given swap location.
263 * @buf: Address we're writing.
264 * @offset: Offset of the swap page we're writing to.
265 */
266
267static int write_page(void *buf, unsigned long offset)
268{
269 swp_entry_t entry;
270 int error = -ENOSPC;
271
272 if (offset) {
273 entry = swp_entry(root_swap, offset);
274 error = rw_swap_page_sync(WRITE, entry, virt_to_page(buf));
275 }
276 return error;
277}
278
279/*
280 * The swap map is a data structure used for keeping track of each page
281 * written to a swap partition. It consists of many swap_map_page
282 * structures that contain each an array of MAP_PAGE_SIZE swap entries.
283 * These structures are stored on the swap and linked together with the
284 * help of the .next_swap member.
285 *
286 * The swap map is created during suspend. The swap map pages are
287 * allocated and populated one at a time, so we only need one memory
288 * page to set up the entire structure.
289 *
290 * During resume we also only need to use one swap_map_page structure
291 * at a time.
292 */
293
294#define MAP_PAGE_ENTRIES (PAGE_SIZE / sizeof(long) - 1)
295
296struct swap_map_page {
297 unsigned long entries[MAP_PAGE_ENTRIES];
298 unsigned long next_swap;
299};
300
301/**
302 * The swap_map_handle structure is used for handling swap in
303 * a file-alike way
304 */
305
306struct swap_map_handle {
307 struct swap_map_page *cur;
308 unsigned long cur_swap;
309 struct bitmap_page *bitmap;
310 unsigned int k;
311};
312
313static void release_swap_writer(struct swap_map_handle *handle)
314{
315 if (handle->cur)
316 free_page((unsigned long)handle->cur);
317 handle->cur = NULL;
318 if (handle->bitmap)
319 free_bitmap(handle->bitmap);
320 handle->bitmap = NULL;
321}
322
323static int get_swap_writer(struct swap_map_handle *handle)
324{
325 handle->cur = (struct swap_map_page *)get_zeroed_page(GFP_KERNEL);
326 if (!handle->cur)
327 return -ENOMEM;
328 handle->bitmap = alloc_bitmap(count_swap_pages(root_swap, 0));
329 if (!handle->bitmap) {
330 release_swap_writer(handle);
331 return -ENOMEM;
332 }
333 handle->cur_swap = alloc_swap_page(root_swap, handle->bitmap);
334 if (!handle->cur_swap) {
335 release_swap_writer(handle);
336 return -ENOSPC;
337 }
338 handle->k = 0;
339 return 0;
340}
341
342static int swap_write_page(struct swap_map_handle *handle, void *buf)
343{
344 int error;
345 unsigned long offset;
346
347 if (!handle->cur)
348 return -EINVAL;
349 offset = alloc_swap_page(root_swap, handle->bitmap);
350 error = write_page(buf, offset);
351 if (error)
352 return error;
353 handle->cur->entries[handle->k++] = offset;
354 if (handle->k >= MAP_PAGE_ENTRIES) {
355 offset = alloc_swap_page(root_swap, handle->bitmap);
356 if (!offset)
357 return -ENOSPC;
358 handle->cur->next_swap = offset;
359 error = write_page(handle->cur, handle->cur_swap);
360 if (error)
361 return error;
362 memset(handle->cur, 0, PAGE_SIZE);
363 handle->cur_swap = offset;
364 handle->k = 0;
365 }
366 return 0;
367}
368
369static int flush_swap_writer(struct swap_map_handle *handle)
370{
371 if (handle->cur && handle->cur_swap)
372 return write_page(handle->cur, handle->cur_swap);
373 else
374 return -EINVAL;
375}
376
377/**
378 * save_image - save the suspend image data
379 */
380
381static int save_image(struct swap_map_handle *handle,
382 struct snapshot_handle *snapshot,
383 unsigned int nr_pages)
384{
385 unsigned int m;
386 int ret;
387 int error = 0;
388
389 printk("Saving image data pages (%u pages) ... ", nr_pages);
390 m = nr_pages / 100;
391 if (!m)
392 m = 1;
393 nr_pages = 0;
394 do {
395 ret = snapshot_read_next(snapshot, PAGE_SIZE);
396 if (ret > 0) {
397 error = swap_write_page(handle, data_of(*snapshot));
398 if (error)
399 break;
400 if (!(nr_pages % m))
401 printk("\b\b\b\b%3d%%", nr_pages / m);
402 nr_pages++;
403 }
404 } while (ret > 0);
405 if (!error)
406 printk("\b\b\b\bdone\n");
407 return error;
408}
409
410/**
411 * enough_swap - Make sure we have enough swap to save the image.
412 *
413 * Returns TRUE or FALSE after checking the total amount of swap
414 * space avaiable from the resume partition.
415 */
416
417static int enough_swap(unsigned int nr_pages)
418{
419 unsigned int free_swap = count_swap_pages(root_swap, 1);
420
421 pr_debug("swsusp: free swap pages: %u\n", free_swap);
422 return free_swap > (nr_pages + PAGES_FOR_IO +
423 (nr_pages + PBES_PER_PAGE - 1) / PBES_PER_PAGE);
424}
425
426/**
427 * swsusp_write - Write entire image and metadata.
428 *
429 * It is important _NOT_ to umount filesystems at this point. We want
430 * them synced (in case something goes wrong) but we DO not want to mark
431 * filesystem clean: it is not. (And it does not matter, if we resume
432 * correctly, we'll mark system clean, anyway.)
433 */
434
435int swsusp_write(void)
436{
437 struct swap_map_handle handle;
438 struct snapshot_handle snapshot;
439 struct swsusp_info *header;
440 unsigned long start;
441 int error;
442
443 if ((error = swsusp_swap_check())) {
444 printk(KERN_ERR "swsusp: Cannot find swap device, try swapon -a.\n");
445 return error;
446 }
447 memset(&snapshot, 0, sizeof(struct snapshot_handle));
448 error = snapshot_read_next(&snapshot, PAGE_SIZE);
449 if (error < PAGE_SIZE)
450 return error < 0 ? error : -EFAULT;
451 header = (struct swsusp_info *)data_of(snapshot);
452 if (!enough_swap(header->pages)) {
453 printk(KERN_ERR "swsusp: Not enough free swap\n");
454 return -ENOSPC;
455 }
456 error = get_swap_writer(&handle);
457 if (!error) {
458 start = handle.cur_swap;
459 error = swap_write_page(&handle, header);
460 }
461 if (!error)
462 error = save_image(&handle, &snapshot, header->pages - 1);
463 if (!error) {
464 flush_swap_writer(&handle);
465 printk("S");
466 error = mark_swapfiles(swp_entry(root_swap, start));
467 printk("|\n");
468 }
469 if (error)
470 free_all_swap_pages(root_swap, handle.bitmap);
471 release_swap_writer(&handle);
472 return error;
473}
474
475/**
476 * swsusp_shrink_memory - Try to free as much memory as needed 169 * swsusp_shrink_memory - Try to free as much memory as needed
477 * 170 *
478 * ... but do not OOM-kill anyone 171 * ... but do not OOM-kill anyone
@@ -578,252 +271,3 @@ int swsusp_resume(void)
578 local_irq_enable(); 271 local_irq_enable();
579 return error; 272 return error;
580} 273}
581
582/*
583 * Using bio to read from swap.
584 * This code requires a bit more work than just using buffer heads
585 * but, it is the recommended way for 2.5/2.6.
586 * The following are to signal the beginning and end of I/O. Bios
587 * finish asynchronously, while we want them to happen synchronously.
588 * A simple atomic_t, and a wait loop take care of this problem.
589 */
590
591static atomic_t io_done = ATOMIC_INIT(0);
592
593static int end_io(struct bio *bio, unsigned int num, int err)
594{
595 if (!test_bit(BIO_UPTODATE, &bio->bi_flags))
596 panic("I/O error reading memory image");
597 atomic_set(&io_done, 0);
598 return 0;
599}
600
601static struct block_device *resume_bdev;
602
603/**
604 * submit - submit BIO request.
605 * @rw: READ or WRITE.
606 * @off physical offset of page.
607 * @page: page we're reading or writing.
608 *
609 * Straight from the textbook - allocate and initialize the bio.
610 * If we're writing, make sure the page is marked as dirty.
611 * Then submit it and wait.
612 */
613
614static int submit(int rw, pgoff_t page_off, void *page)
615{
616 int error = 0;
617 struct bio *bio;
618
619 bio = bio_alloc(GFP_ATOMIC, 1);
620 if (!bio)
621 return -ENOMEM;
622 bio->bi_sector = page_off * (PAGE_SIZE >> 9);
623 bio->bi_bdev = resume_bdev;
624 bio->bi_end_io = end_io;
625
626 if (bio_add_page(bio, virt_to_page(page), PAGE_SIZE, 0) < PAGE_SIZE) {
627 printk("swsusp: ERROR: adding page to bio at %ld\n",page_off);
628 error = -EFAULT;
629 goto Done;
630 }
631
632
633 atomic_set(&io_done, 1);
634 submit_bio(rw | (1 << BIO_RW_SYNC), bio);
635 while (atomic_read(&io_done))
636 yield();
637 if (rw == READ)
638 bio_set_pages_dirty(bio);
639 Done:
640 bio_put(bio);
641 return error;
642}
643
644static int bio_read_page(pgoff_t page_off, void *page)
645{
646 return submit(READ, page_off, page);
647}
648
649static int bio_write_page(pgoff_t page_off, void *page)
650{
651 return submit(WRITE, page_off, page);
652}
653
654/**
655 * The following functions allow us to read data using a swap map
656 * in a file-alike way
657 */
658
659static void release_swap_reader(struct swap_map_handle *handle)
660{
661 if (handle->cur)
662 free_page((unsigned long)handle->cur);
663 handle->cur = NULL;
664}
665
666static int get_swap_reader(struct swap_map_handle *handle,
667 swp_entry_t start)
668{
669 int error;
670
671 if (!swp_offset(start))
672 return -EINVAL;
673 handle->cur = (struct swap_map_page *)get_zeroed_page(GFP_ATOMIC);
674 if (!handle->cur)
675 return -ENOMEM;
676 error = bio_read_page(swp_offset(start), handle->cur);
677 if (error) {
678 release_swap_reader(handle);
679 return error;
680 }
681 handle->k = 0;
682 return 0;
683}
684
685static int swap_read_page(struct swap_map_handle *handle, void *buf)
686{
687 unsigned long offset;
688 int error;
689
690 if (!handle->cur)
691 return -EINVAL;
692 offset = handle->cur->entries[handle->k];
693 if (!offset)
694 return -EFAULT;
695 error = bio_read_page(offset, buf);
696 if (error)
697 return error;
698 if (++handle->k >= MAP_PAGE_ENTRIES) {
699 handle->k = 0;
700 offset = handle->cur->next_swap;
701 if (!offset)
702 release_swap_reader(handle);
703 else
704 error = bio_read_page(offset, handle->cur);
705 }
706 return error;
707}
708
709/**
710 * load_image - load the image using the swap map handle
711 * @handle and the snapshot handle @snapshot
712 * (assume there are @nr_pages pages to load)
713 */
714
715static int load_image(struct swap_map_handle *handle,
716 struct snapshot_handle *snapshot,
717 unsigned int nr_pages)
718{
719 unsigned int m;
720 int ret;
721 int error = 0;
722
723 printk("Loading image data pages (%u pages) ... ", nr_pages);
724 m = nr_pages / 100;
725 if (!m)
726 m = 1;
727 nr_pages = 0;
728 do {
729 ret = snapshot_write_next(snapshot, PAGE_SIZE);
730 if (ret > 0) {
731 error = swap_read_page(handle, data_of(*snapshot));
732 if (error)
733 break;
734 if (!(nr_pages % m))
735 printk("\b\b\b\b%3d%%", nr_pages / m);
736 nr_pages++;
737 }
738 } while (ret > 0);
739 if (!error)
740 printk("\b\b\b\bdone\n");
741 if (!snapshot_image_loaded(snapshot))
742 error = -ENODATA;
743 return error;
744}
745
746int swsusp_read(void)
747{
748 int error;
749 struct swap_map_handle handle;
750 struct snapshot_handle snapshot;
751 struct swsusp_info *header;
752 unsigned int nr_pages;
753
754 if (IS_ERR(resume_bdev)) {
755 pr_debug("swsusp: block device not initialised\n");
756 return PTR_ERR(resume_bdev);
757 }
758
759 memset(&snapshot, 0, sizeof(struct snapshot_handle));
760 error = snapshot_write_next(&snapshot, PAGE_SIZE);
761 if (error < PAGE_SIZE)
762 return error < 0 ? error : -EFAULT;
763 header = (struct swsusp_info *)data_of(snapshot);
764 error = get_swap_reader(&handle, swsusp_header.image);
765 if (!error)
766 error = swap_read_page(&handle, header);
767 if (!error) {
768 nr_pages = header->image_pages;
769 error = load_image(&handle, &snapshot, nr_pages);
770 }
771 release_swap_reader(&handle);
772
773 blkdev_put(resume_bdev);
774
775 if (!error)
776 pr_debug("swsusp: Reading resume file was successful\n");
777 else
778 pr_debug("swsusp: Error %d resuming\n", error);
779 return error;
780}
781
782/**
783 * swsusp_check - Check for swsusp signature in the resume device
784 */
785
786int swsusp_check(void)
787{
788 int error;
789
790 resume_bdev = open_by_devnum(swsusp_resume_device, FMODE_READ);
791 if (!IS_ERR(resume_bdev)) {
792 set_blocksize(resume_bdev, PAGE_SIZE);
793 memset(&swsusp_header, 0, sizeof(swsusp_header));
794 if ((error = bio_read_page(0, &swsusp_header)))
795 return error;
796 if (!memcmp(SWSUSP_SIG, swsusp_header.sig, 10)) {
797 memcpy(swsusp_header.sig, swsusp_header.orig_sig, 10);
798 /* Reset swap signature now */
799 error = bio_write_page(0, &swsusp_header);
800 } else {
801 return -EINVAL;
802 }
803 if (error)
804 blkdev_put(resume_bdev);
805 else
806 pr_debug("swsusp: Signature found, resuming\n");
807 } else {
808 error = PTR_ERR(resume_bdev);
809 }
810
811 if (error)
812 pr_debug("swsusp: Error %d check for resume file\n", error);
813
814 return error;
815}
816
817/**
818 * swsusp_close - close swap device.
819 */
820
821void swsusp_close(void)
822{
823 if (IS_ERR(resume_bdev)) {
824 pr_debug("swsusp: block device not initialised\n");
825 return;
826 }
827
828 blkdev_put(resume_bdev);
829}
generated by cgit v1.2.2 (git 2.25.0) at 2024-11-05 18:57:57 -0500