swsusp.c 34.9 KB
Newer Older
L
Linus Torvalds 已提交
1 2 3 4 5 6 7 8 9 10 11 12
/*
 * linux/kernel/power/swsusp.c
 *
 * This file is to realize architecture-independent
 * machine suspend feature using pretty near only high-level routines
 *
 * Copyright (C) 1998-2001 Gabor Kuti <seasons@fornax.hu>
 * Copyright (C) 1998,2001-2004 Pavel Machek <pavel@suse.cz>
 *
 * This file is released under the GPLv2.
 *
 * I'd like to thank the following people for their work:
13
 *
L
Linus Torvalds 已提交
14 15 16 17
 * Pavel Machek <pavel@ucw.cz>:
 * Modifications, defectiveness pointing, being with me at the very beginning,
 * suspend to swap space, stop all tasks. Port to 2.4.18-ac and 2.5.17.
 *
18
 * Steve Doddi <dirk@loth.demon.co.uk>:
L
Linus Torvalds 已提交
19 20 21 22 23 24 25 26 27 28 29 30 31 32 33
 * Support the possibility of hardware state restoring.
 *
 * Raph <grey.havens@earthling.net>:
 * Support for preserving states of network devices and virtual console
 * (including X and svgatextmode)
 *
 * Kurt Garloff <garloff@suse.de>:
 * Straightened the critical function in order to prevent compilers from
 * playing tricks with local variables.
 *
 * Andreas Mohr <a.mohr@mailto.de>
 *
 * Alex Badea <vampire@go.ro>:
 * Fixed runaway init
 *
34 35 36
 * Andreas Steinmetz <ast@domdv.de>:
 * Added encrypted suspend option
 *
L
Linus Torvalds 已提交
37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68
 * More state savers are welcome. Especially for the scsi layer...
 *
 * For TODOs,FIXMEs also look in Documentation/power/swsusp.txt
 */

#include <linux/module.h>
#include <linux/mm.h>
#include <linux/suspend.h>
#include <linux/smp_lock.h>
#include <linux/file.h>
#include <linux/utsname.h>
#include <linux/version.h>
#include <linux/delay.h>
#include <linux/reboot.h>
#include <linux/bitops.h>
#include <linux/vt_kern.h>
#include <linux/kbd_kern.h>
#include <linux/keyboard.h>
#include <linux/spinlock.h>
#include <linux/genhd.h>
#include <linux/kernel.h>
#include <linux/major.h>
#include <linux/swap.h>
#include <linux/pm.h>
#include <linux/device.h>
#include <linux/buffer_head.h>
#include <linux/swapops.h>
#include <linux/bootmem.h>
#include <linux/syscalls.h>
#include <linux/console.h>
#include <linux/highmem.h>
#include <linux/bio.h>
69
#include <linux/mount.h>
L
Linus Torvalds 已提交
70 71 72 73 74 75 76

#include <asm/uaccess.h>
#include <asm/mmu_context.h>
#include <asm/pgtable.h>
#include <asm/tlbflush.h>
#include <asm/io.h>

77 78 79 80
#include <linux/random.h>
#include <linux/crypto.h>
#include <asm/scatterlist.h>

L
Linus Torvalds 已提交
81 82
#include "power.h"

83 84 85 86
#define CIPHER "aes"
#define MAXKEY 32
#define MAXIV  32

L
Linus Torvalds 已提交
87 88 89 90 91 92 93 94 95
/* References to section boundaries */
extern const void __nosave_begin, __nosave_end;

/* Variables to be preserved over suspend */
static int nr_copy_pages_check;

extern char resume_file[];

/* Local variables that should not be affected by save */
A
Adrian Bunk 已提交
96
static unsigned int nr_copy_pages __nosavedata = 0;
L
Linus Torvalds 已提交
97 98

/* Suspend pagedir is allocated before final copy, therefore it
99
   must be freed after resume
L
Linus Torvalds 已提交
100 101 102

   Warning: this is evil. There are actually two pagedirs at time of
   resume. One is "pagedir_save", which is empty frame allocated at
103
   time of suspend, that must be freed. Second is "pagedir_nosave",
L
Linus Torvalds 已提交
104 105 106 107 108 109 110 111 112 113 114 115 116
   allocated at time of resume, that travels through memory not to
   collide with anything.

   Warning: this is even more evil than it seems. Pagedirs this file
   talks about are completely different from page directories used by
   MMU hardware.
 */
suspend_pagedir_t *pagedir_nosave __nosavedata = NULL;
static suspend_pagedir_t *pagedir_save;

#define SWSUSP_SIG	"S1SUSPEND"

static struct swsusp_header {
117 118
	char reserved[PAGE_SIZE - 20 - MAXKEY - MAXIV - sizeof(swp_entry_t)];
	u8 key_iv[MAXKEY+MAXIV];
L
Linus Torvalds 已提交
119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143
	swp_entry_t swsusp_info;
	char	orig_sig[10];
	char	sig[10];
} __attribute__((packed, aligned(PAGE_SIZE))) swsusp_header;

static struct swsusp_info swsusp_info;

/*
 * XXX: We try to keep some more pages free so that I/O operations succeed
 * without paging. Might this be more?
 */
#define PAGES_FOR_IO	512

/*
 * Saving part...
 */

/* We memorize in swapfile_used what swap devices are used for suspension */
#define SWAPFILE_UNUSED    0
#define SWAPFILE_SUSPEND   1	/* This is the suspending device */
#define SWAPFILE_IGNORED   2	/* Those are other swap devices ignored for suspension */

static unsigned short swapfile_used[MAX_SWAPFILES];
static unsigned short root_swap;

144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 185 186 187 188 189 190 191 192 193 194 195 196 197 198 199 200 201 202 203 204 205 206 207 208 209 210 211 212 213 214 215 216 217 218 219 220 221 222 223 224 225 226 227 228 229 230 231 232 233 234 235 236 237 238 239 240 241 242 243 244 245 246 247 248 249 250 251 252 253 254 255 256 257 258 259 260 261 262 263 264 265 266 267 268
static int write_page(unsigned long addr, swp_entry_t * loc);
static int bio_read_page(pgoff_t page_off, void * page);

static u8 key_iv[MAXKEY+MAXIV];

#ifdef CONFIG_SWSUSP_ENCRYPT

static int crypto_init(int mode, void **mem)
{
	int error = 0;
	int len;
	char *modemsg;
	struct crypto_tfm *tfm;

	modemsg = mode ? "suspend not possible" : "resume not possible";

	tfm = crypto_alloc_tfm(CIPHER, CRYPTO_TFM_MODE_CBC);
	if(!tfm) {
		printk(KERN_ERR "swsusp: no tfm, %s\n", modemsg);
		error = -EINVAL;
		goto out;
	}

	if(MAXKEY < crypto_tfm_alg_min_keysize(tfm)) {
		printk(KERN_ERR "swsusp: key buffer too small, %s\n", modemsg);
		error = -ENOKEY;
		goto fail;
	}

	if (mode)
		get_random_bytes(key_iv, MAXKEY+MAXIV);

	len = crypto_tfm_alg_max_keysize(tfm);
	if (len > MAXKEY)
		len = MAXKEY;

	if (crypto_cipher_setkey(tfm, key_iv, len)) {
		printk(KERN_ERR "swsusp: key setup failure, %s\n", modemsg);
		error = -EKEYREJECTED;
		goto fail;
	}

	len = crypto_tfm_alg_ivsize(tfm);

	if (MAXIV < len) {
		printk(KERN_ERR "swsusp: iv buffer too small, %s\n", modemsg);
		error = -EOVERFLOW;
		goto fail;
	}

	crypto_cipher_set_iv(tfm, key_iv+MAXKEY, len);

	*mem=(void *)tfm;

	goto out;

fail:	crypto_free_tfm(tfm);
out:	return error;
}

static __inline__ void crypto_exit(void *mem)
{
	crypto_free_tfm((struct crypto_tfm *)mem);
}

static __inline__ int crypto_write(struct pbe *p, void *mem)
{
	int error = 0;
	struct scatterlist src, dst;

	src.page   = virt_to_page(p->address);
	src.offset = 0;
	src.length = PAGE_SIZE;
	dst.page   = virt_to_page((void *)&swsusp_header);
	dst.offset = 0;
	dst.length = PAGE_SIZE;

	error = crypto_cipher_encrypt((struct crypto_tfm *)mem, &dst, &src,
					PAGE_SIZE);

	if (!error)
		error = write_page((unsigned long)&swsusp_header,
				&(p->swap_address));
	return error;
}

static __inline__ int crypto_read(struct pbe *p, void *mem)
{
	int error = 0;
	struct scatterlist src, dst;

	error = bio_read_page(swp_offset(p->swap_address), (void *)p->address);
	if (!error) {
		src.offset = 0;
		src.length = PAGE_SIZE;
		dst.offset = 0;
		dst.length = PAGE_SIZE;
		src.page = dst.page = virt_to_page((void *)p->address);

		error = crypto_cipher_decrypt((struct crypto_tfm *)mem, &dst,
						&src, PAGE_SIZE);
	}
	return error;
}
#else
static __inline__ int crypto_init(int mode, void *mem)
{
	return 0;
}

static __inline__ void crypto_exit(void *mem)
{
}

static __inline__ int crypto_write(struct pbe *p, void *mem)
{
	return write_page(p->address, &(p->swap_address));
}

static __inline__ int crypto_read(struct pbe *p, void *mem)
{
	return bio_read_page(swp_offset(p->swap_address), (void *)p->address);
}
#endif

L
Linus Torvalds 已提交
269 270 271 272
static int mark_swapfiles(swp_entry_t prev)
{
	int error;

273
	rw_swap_page_sync(READ,
L
Linus Torvalds 已提交
274 275 276 277 278 279
			  swp_entry(root_swap, 0),
			  virt_to_page((unsigned long)&swsusp_header));
	if (!memcmp("SWAP-SPACE",swsusp_header.sig, 10) ||
	    !memcmp("SWAPSPACE2",swsusp_header.sig, 10)) {
		memcpy(swsusp_header.orig_sig,swsusp_header.sig, 10);
		memcpy(swsusp_header.sig,SWSUSP_SIG, 10);
280
		memcpy(swsusp_header.key_iv, key_iv, MAXKEY+MAXIV);
L
Linus Torvalds 已提交
281
		swsusp_header.swsusp_info = prev;
282
		error = rw_swap_page_sync(WRITE,
L
Linus Torvalds 已提交
283 284 285 286 287 288 289 290 291 292 293 294 295 296 297 298 299 300 301 302 303 304 305 306 307 308 309 310 311 312 313 314 315
					  swp_entry(root_swap, 0),
					  virt_to_page((unsigned long)
						       &swsusp_header));
	} else {
		pr_debug("swsusp: Partition is not swap space.\n");
		error = -ENODEV;
	}
	return error;
}

/*
 * Check whether the swap device is the specified resume
 * device, irrespective of whether they are specified by
 * identical names.
 *
 * (Thus, device inode aliasing is allowed.  You can say /dev/hda4
 * instead of /dev/ide/host0/bus0/target0/lun0/part4 [if using devfs]
 * and they'll be considered the same device.  This is *necessary* for
 * devfs, since the resume code can only recognize the form /dev/hda4,
 * but the suspend code would see the long name.)
 */
static int is_resume_device(const struct swap_info_struct *swap_info)
{
	struct file *file = swap_info->swap_file;
	struct inode *inode = file->f_dentry->d_inode;

	return S_ISBLK(inode->i_mode) &&
		swsusp_resume_device == MKDEV(imajor(inode), iminor(inode));
}

static int swsusp_swap_check(void) /* This is called before saving image */
{
	int i, len;
316

L
Linus Torvalds 已提交
317 318
	len=strlen(resume_file);
	root_swap = 0xFFFF;
319

320
	spin_lock(&swap_lock);
321
	for (i=0; i<MAX_SWAPFILES; i++) {
322
		if (!(swap_info[i].flags & SWP_WRITEOK)) {
L
Linus Torvalds 已提交
323 324
			swapfile_used[i]=SWAPFILE_UNUSED;
		} else {
325
			if (!len) {
L
Linus Torvalds 已提交
326
	    			printk(KERN_WARNING "resume= option should be used to set suspend device" );
327
				if (root_swap == 0xFFFF) {
L
Linus Torvalds 已提交
328 329 330
					swapfile_used[i] = SWAPFILE_SUSPEND;
					root_swap = i;
				} else
331
					swapfile_used[i] = SWAPFILE_IGNORED;
L
Linus Torvalds 已提交
332 333 334 335 336 337 338 339 340 341 342
			} else {
	  			/* we ignore all swap devices that are not the resume_file */
				if (is_resume_device(&swap_info[i])) {
					swapfile_used[i] = SWAPFILE_SUSPEND;
					root_swap = i;
				} else {
				  	swapfile_used[i] = SWAPFILE_IGNORED;
				}
			}
		}
	}
343
	spin_unlock(&swap_lock);
L
Linus Torvalds 已提交
344 345 346 347 348 349 350
	return (root_swap != 0xffff) ? 0 : -ENODEV;
}

/**
 * This is called after saving image so modification
 * will be lost after resume... and that's what we want.
 * we make the device unusable. A new call to
351
 * lock_swapdevices can unlock the devices.
L
Linus Torvalds 已提交
352 353 354 355 356
 */
static void lock_swapdevices(void)
{
	int i;

357
	spin_lock(&swap_lock);
358 359
	for (i = 0; i< MAX_SWAPFILES; i++)
		if (swapfile_used[i] == SWAPFILE_IGNORED) {
360
			swap_info[i].flags ^= SWP_WRITEOK;
L
Linus Torvalds 已提交
361
		}
362
	spin_unlock(&swap_lock);
L
Linus Torvalds 已提交
363 364 365 366 367 368 369 370
}

/**
 *	write_swap_page - Write one page to a fresh swap location.
 *	@addr:	Address we're writing.
 *	@loc:	Place to store the entry we used.
 *
 *	Allocate a new swap entry and 'sync' it. Note we discard -EIO
371
 *	errors. That is an artifact left over from swsusp. It did not
L
Linus Torvalds 已提交
372 373 374 375 376 377 378 379 380 381 382
 *	check the return of rw_swap_page_sync() at all, since most pages
 *	written back to swap would return -EIO.
 *	This is a partial improvement, since we will at least return other
 *	errors, though we need to eventually fix the damn code.
 */
static int write_page(unsigned long addr, swp_entry_t * loc)
{
	swp_entry_t entry;
	int error = 0;

	entry = get_swap_page();
383
	if (swp_offset(entry) &&
L
Linus Torvalds 已提交
384 385 386 387 388 389 390 391 392 393 394 395 396 397 398
	    swapfile_used[swp_type(entry)] == SWAPFILE_SUSPEND) {
		error = rw_swap_page_sync(WRITE, entry,
					  virt_to_page(addr));
		if (error == -EIO)
			error = 0;
		if (!error)
			*loc = entry;
	} else
		error = -ENOSPC;
	return error;
}

/**
 *	data_free - Free the swap entries used by the saved image.
 *
399
 *	Walk the list of used swap entries and free each one.
L
Linus Torvalds 已提交
400 401 402 403 404 405 406 407 408 409 410 411 412 413 414 415 416 417 418 419 420 421 422 423 424 425 426
 *	This is only used for cleanup when suspend fails.
 */
static void data_free(void)
{
	swp_entry_t entry;
	int i;

	for (i = 0; i < nr_copy_pages; i++) {
		entry = (pagedir_nosave + i)->swap_address;
		if (entry.val)
			swap_free(entry);
		else
			break;
		(pagedir_nosave + i)->swap_address = (swp_entry_t){0};
	}
}

/**
 *	data_write - Write saved image to swap.
 *
 *	Walk the list of pages in the image and sync each one to swap.
 */
static int data_write(void)
{
	int error = 0, i = 0;
	unsigned int mod = nr_copy_pages / 100;
	struct pbe *p;
427 428 429 430
	void *tfm;

	if ((error = crypto_init(1, &tfm)))
		return error;
L
Linus Torvalds 已提交
431 432 433 434 435

	if (!mod)
		mod = 1;

	printk( "Writing data to swap (%d pages)...     ", nr_copy_pages );
436
	for_each_pbe (p, pagedir_nosave) {
L
Linus Torvalds 已提交
437 438
		if (!(i%mod))
			printk( "\b\b\b\b%3d%%", i / mod );
439 440
		if ((error = crypto_write(p, tfm))) {
			crypto_exit(tfm);
L
Linus Torvalds 已提交
441
			return error;
442
		}
L
Linus Torvalds 已提交
443 444 445
		i++;
	}
	printk("\b\b\b\bdone\n");
446
	crypto_exit(tfm);
L
Linus Torvalds 已提交
447 448 449 450 451 452 453 454 455 456 457 458 459 460 461 462 463 464 465 466 467 468 469 470 471 472 473 474 475 476 477 478 479 480 481 482 483
	return error;
}

static void dump_info(void)
{
	pr_debug(" swsusp: Version: %u\n",swsusp_info.version_code);
	pr_debug(" swsusp: Num Pages: %ld\n",swsusp_info.num_physpages);
	pr_debug(" swsusp: UTS Sys: %s\n",swsusp_info.uts.sysname);
	pr_debug(" swsusp: UTS Node: %s\n",swsusp_info.uts.nodename);
	pr_debug(" swsusp: UTS Release: %s\n",swsusp_info.uts.release);
	pr_debug(" swsusp: UTS Version: %s\n",swsusp_info.uts.version);
	pr_debug(" swsusp: UTS Machine: %s\n",swsusp_info.uts.machine);
	pr_debug(" swsusp: UTS Domain: %s\n",swsusp_info.uts.domainname);
	pr_debug(" swsusp: CPUs: %d\n",swsusp_info.cpus);
	pr_debug(" swsusp: Image: %ld Pages\n",swsusp_info.image_pages);
	pr_debug(" swsusp: Pagedir: %ld Pages\n",swsusp_info.pagedir_pages);
}

static void init_header(void)
{
	memset(&swsusp_info, 0, sizeof(swsusp_info));
	swsusp_info.version_code = LINUX_VERSION_CODE;
	swsusp_info.num_physpages = num_physpages;
	memcpy(&swsusp_info.uts, &system_utsname, sizeof(system_utsname));

	swsusp_info.suspend_pagedir = pagedir_nosave;
	swsusp_info.cpus = num_online_cpus();
	swsusp_info.image_pages = nr_copy_pages;
}

static int close_swap(void)
{
	swp_entry_t entry;
	int error;

	dump_info();
	error = write_page((unsigned long)&swsusp_info, &entry);
484
	if (!error) {
L
Linus Torvalds 已提交
485 486 487 488 489 490 491 492 493 494 495 496 497 498 499 500 501 502 503 504 505 506 507 508 509 510 511 512 513 514 515 516 517 518
		printk( "S" );
		error = mark_swapfiles(entry);
		printk( "|\n" );
	}
	return error;
}

/**
 *	free_pagedir_entries - Free pages used by the page directory.
 *
 *	This is used during suspend for error recovery.
 */

static void free_pagedir_entries(void)
{
	int i;

	for (i = 0; i < swsusp_info.pagedir_pages; i++)
		swap_free(swsusp_info.pagedir[i]);
}


/**
 *	write_pagedir - Write the array of pages holding the page directory.
 *	@last:	Last swap entry we write (needed for header).
 */

static int write_pagedir(void)
{
	int error = 0;
	unsigned n = 0;
	struct pbe * pbe;

	printk( "Writing pagedir...");
519
	for_each_pb_page (pbe, pagedir_nosave) {
L
Linus Torvalds 已提交
520 521 522 523 524 525 526 527 528 529 530 531 532 533 534 535 536 537 538 539 540 541 542 543 544 545 546 547
		if ((error = write_page((unsigned long)pbe, &swsusp_info.pagedir[n++])))
			return error;
	}

	swsusp_info.pagedir_pages = n;
	printk("done (%u pages)\n", n);
	return error;
}

/**
 *	write_suspend_image - Write entire image and metadata.
 *
 */

static int write_suspend_image(void)
{
	int error;

	init_header();
	if ((error = data_write()))
		goto FreeData;

	if ((error = write_pagedir()))
		goto FreePagedir;

	if ((error = close_swap()))
		goto FreePagedir;
 Done:
548
	memset(key_iv, 0, MAXKEY+MAXIV);
L
Linus Torvalds 已提交
549 550 551 552 553 554 555 556 557 558 559 560 561 562 563 564 565 566 567 568 569 570 571 572 573 574 575 576 577 578 579 580 581 582 583 584 585 586 587 588 589 590 591 592 593 594 595 596 597 598 599 600 601 602 603 604 605 606 607 608 609 610 611 612 613 614 615 616 617 618 619 620 621
	return error;
 FreePagedir:
	free_pagedir_entries();
 FreeData:
	data_free();
	goto Done;
}


#ifdef CONFIG_HIGHMEM
struct highmem_page {
	char *data;
	struct page *page;
	struct highmem_page *next;
};

static struct highmem_page *highmem_copy;

static int save_highmem_zone(struct zone *zone)
{
	unsigned long zone_pfn;
	mark_free_pages(zone);
	for (zone_pfn = 0; zone_pfn < zone->spanned_pages; ++zone_pfn) {
		struct page *page;
		struct highmem_page *save;
		void *kaddr;
		unsigned long pfn = zone_pfn + zone->zone_start_pfn;

		if (!(pfn%1000))
			printk(".");
		if (!pfn_valid(pfn))
			continue;
		page = pfn_to_page(pfn);
		/*
		 * This condition results from rvmalloc() sans vmalloc_32()
		 * and architectural memory reservations. This should be
		 * corrected eventually when the cases giving rise to this
		 * are better understood.
		 */
		if (PageReserved(page)) {
			printk("highmem reserved page?!\n");
			continue;
		}
		BUG_ON(PageNosave(page));
		if (PageNosaveFree(page))
			continue;
		save = kmalloc(sizeof(struct highmem_page), GFP_ATOMIC);
		if (!save)
			return -ENOMEM;
		save->next = highmem_copy;
		save->page = page;
		save->data = (void *) get_zeroed_page(GFP_ATOMIC);
		if (!save->data) {
			kfree(save);
			return -ENOMEM;
		}
		kaddr = kmap_atomic(page, KM_USER0);
		memcpy(save->data, kaddr, PAGE_SIZE);
		kunmap_atomic(kaddr, KM_USER0);
		highmem_copy = save;
	}
	return 0;
}
#endif /* CONFIG_HIGHMEM */


static int save_highmem(void)
{
#ifdef CONFIG_HIGHMEM
	struct zone *zone;
	int res = 0;

	pr_debug("swsusp: Saving Highmem\n");
622
	for_each_zone (zone) {
L
Linus Torvalds 已提交
623 624 625 626 627 628 629 630 631 632 633 634 635 636 637 638 639 640 641 642 643 644 645 646 647 648 649 650 651 652 653 654 655 656 657 658 659 660 661 662 663 664 665 666 667 668 669 670 671 672 673 674 675 676 677 678 679 680 681 682 683 684 685 686 687 688 689 690 691 692 693 694 695 696
		if (is_highmem(zone))
			res = save_highmem_zone(zone);
		if (res)
			return res;
	}
#endif
	return 0;
}

static int restore_highmem(void)
{
#ifdef CONFIG_HIGHMEM
	printk("swsusp: Restoring Highmem\n");
	while (highmem_copy) {
		struct highmem_page *save = highmem_copy;
		void *kaddr;
		highmem_copy = save->next;

		kaddr = kmap_atomic(save->page, KM_USER0);
		memcpy(kaddr, save->data, PAGE_SIZE);
		kunmap_atomic(kaddr, KM_USER0);
		free_page((long) save->data);
		kfree(save);
	}
#endif
	return 0;
}


static int pfn_is_nosave(unsigned long pfn)
{
	unsigned long nosave_begin_pfn = __pa(&__nosave_begin) >> PAGE_SHIFT;
	unsigned long nosave_end_pfn = PAGE_ALIGN(__pa(&__nosave_end)) >> PAGE_SHIFT;
	return (pfn >= nosave_begin_pfn) && (pfn < nosave_end_pfn);
}

/**
 *	saveable - Determine whether a page should be cloned or not.
 *	@pfn:	The page
 *
 *	We save a page if it's Reserved, and not in the range of pages
 *	statically defined as 'unsaveable', or if it isn't reserved, and
 *	isn't part of a free chunk of pages.
 */

static int saveable(struct zone * zone, unsigned long * zone_pfn)
{
	unsigned long pfn = *zone_pfn + zone->zone_start_pfn;
	struct page * page;

	if (!pfn_valid(pfn))
		return 0;

	page = pfn_to_page(pfn);
	BUG_ON(PageReserved(page) && PageNosave(page));
	if (PageNosave(page))
		return 0;
	if (PageReserved(page) && pfn_is_nosave(pfn)) {
		pr_debug("[nosave pfn 0x%lx]", pfn);
		return 0;
	}
	if (PageNosaveFree(page))
		return 0;

	return 1;
}

static void count_data_pages(void)
{
	struct zone *zone;
	unsigned long zone_pfn;

	nr_copy_pages = 0;

697
	for_each_zone (zone) {
L
Linus Torvalds 已提交
698 699 700 701 702 703 704 705 706 707 708 709 710 711
		if (is_highmem(zone))
			continue;
		mark_free_pages(zone);
		for (zone_pfn = 0; zone_pfn < zone->spanned_pages; ++zone_pfn)
			nr_copy_pages += saveable(zone, &zone_pfn);
	}
}


static void copy_data_pages(void)
{
	struct zone *zone;
	unsigned long zone_pfn;
	struct pbe * pbe = pagedir_nosave;
712

L
Linus Torvalds 已提交
713
	pr_debug("copy_data_pages(): pages to copy: %d\n", nr_copy_pages);
714
	for_each_zone (zone) {
L
Linus Torvalds 已提交
715 716 717 718 719 720 721 722 723 724 725 726 727 728 729 730 731 732 733 734 735 736 737 738 739
		if (is_highmem(zone))
			continue;
		mark_free_pages(zone);
		for (zone_pfn = 0; zone_pfn < zone->spanned_pages; ++zone_pfn) {
			if (saveable(zone, &zone_pfn)) {
				struct page * page;
				page = pfn_to_page(zone_pfn + zone->zone_start_pfn);
				BUG_ON(!pbe);
				pbe->orig_address = (long) page_address(page);
				/* copy_page is not usable for copying task structs. */
				memcpy((void *)pbe->address, (void *)pbe->orig_address, PAGE_SIZE);
				pbe = pbe->next;
			}
		}
	}
	BUG_ON(pbe);
}


/**
 *	calc_nr - Determine the number of pages needed for a pbe list.
 */

static int calc_nr(int nr_copy)
{
740
	return nr_copy + (nr_copy+PBES_PER_PAGE-2)/(PBES_PER_PAGE-1);
L
Linus Torvalds 已提交
741 742 743 744 745 746 747 748 749 750 751 752 753 754 755 756 757 758 759 760 761 762 763 764 765 766 767 768 769 770 771 772 773 774 775 776 777 778 779 780 781 782 783 784 785 786 787 788 789 790 791 792 793 794 795 796 797 798 799 800 801 802 803 804 805 806 807 808 809 810 811 812 813 814 815 816 817 818 819 820 821 822 823 824 825 826 827 828 829 830 831 832 833 834 835 836 837 838 839 840
}

/**
 *	free_pagedir - free pages allocated with alloc_pagedir()
 */

static inline void free_pagedir(struct pbe *pblist)
{
	struct pbe *pbe;

	while (pblist) {
		pbe = (pblist + PB_PAGE_SKIP)->next;
		free_page((unsigned long)pblist);
		pblist = pbe;
	}
}

/**
 *	fill_pb_page - Create a list of PBEs on a given memory page
 */

static inline void fill_pb_page(struct pbe *pbpage)
{
	struct pbe *p;

	p = pbpage;
	pbpage += PB_PAGE_SKIP;
	do
		p->next = p + 1;
	while (++p < pbpage);
}

/**
 *	create_pbe_list - Create a list of PBEs on top of a given chain
 *	of memory pages allocated with alloc_pagedir()
 */

static void create_pbe_list(struct pbe *pblist, unsigned nr_pages)
{
	struct pbe *pbpage, *p;
	unsigned num = PBES_PER_PAGE;

	for_each_pb_page (pbpage, pblist) {
		if (num >= nr_pages)
			break;

		fill_pb_page(pbpage);
		num += PBES_PER_PAGE;
	}
	if (pbpage) {
		for (num -= PBES_PER_PAGE - 1, p = pbpage; num < nr_pages; p++, num++)
			p->next = p + 1;
		p->next = NULL;
	}
	pr_debug("create_pbe_list(): initialized %d PBEs\n", num);
}

/**
 *	alloc_pagedir - Allocate the page directory.
 *
 *	First, determine exactly how many pages we need and
 *	allocate them.
 *
 *	We arrange the pages in a chain: each page is an array of PBES_PER_PAGE
 *	struct pbe elements (pbes) and the last element in the page points
 *	to the next page.
 *
 *	On each page we set up a list of struct_pbe elements.
 */

static struct pbe * alloc_pagedir(unsigned nr_pages)
{
	unsigned num;
	struct pbe *pblist, *pbe;

	if (!nr_pages)
		return NULL;

	pr_debug("alloc_pagedir(): nr_pages = %d\n", nr_pages);
	pblist = (struct pbe *)get_zeroed_page(GFP_ATOMIC | __GFP_COLD);
	for (pbe = pblist, num = PBES_PER_PAGE; pbe && num < nr_pages;
        		pbe = pbe->next, num += PBES_PER_PAGE) {
		pbe += PB_PAGE_SKIP;
		pbe->next = (struct pbe *)get_zeroed_page(GFP_ATOMIC | __GFP_COLD);
	}
	if (!pbe) { /* get_zeroed_page() failed */
		free_pagedir(pblist);
		pblist = NULL;
        }
	return pblist;
}

/**
 *	free_image_pages - Free pages allocated for snapshot
 */

static void free_image_pages(void)
{
	struct pbe * p;

841
	for_each_pbe (p, pagedir_save) {
L
Linus Torvalds 已提交
842 843 844 845 846 847 848 849 850 851 852 853 854 855 856 857
		if (p->address) {
			ClearPageNosave(virt_to_page(p->address));
			free_page(p->address);
			p->address = 0;
		}
	}
}

/**
 *	alloc_image_pages - Allocate pages for the snapshot.
 */

static int alloc_image_pages(void)
{
	struct pbe * p;

858
	for_each_pbe (p, pagedir_save) {
L
Linus Torvalds 已提交
859 860 861 862 863 864 865 866 867 868 869 870 871 872 873 874 875 876 877 878
		p->address = get_zeroed_page(GFP_ATOMIC | __GFP_COLD);
		if (!p->address)
			return -ENOMEM;
		SetPageNosave(virt_to_page(p->address));
	}
	return 0;
}

void swsusp_free(void)
{
	BUG_ON(PageNosave(virt_to_page(pagedir_save)));
	BUG_ON(PageNosaveFree(virt_to_page(pagedir_save)));
	free_image_pages();
	free_pagedir(pagedir_save);
}


/**
 *	enough_free_mem - Make sure we enough free memory to snapshot.
 *
879
 *	Returns TRUE or FALSE after checking the number of available
L
Linus Torvalds 已提交
880 881 882 883 884 885 886 887 888 889 890 891 892 893 894 895 896
 *	free pages.
 */

static int enough_free_mem(void)
{
	if (nr_free_pages() < (nr_copy_pages + PAGES_FOR_IO)) {
		pr_debug("swsusp: Not enough free pages: Have %d\n",
			 nr_free_pages());
		return 0;
	}
	return 1;
}


/**
 *	enough_swap - Make sure we have enough swap to save the image.
 *
897
 *	Returns TRUE or FALSE after checking the total amount of swap
L
Linus Torvalds 已提交
898 899 900
 *	space avaiable.
 *
 *	FIXME: si_swapinfo(&i) returns all swap devices information.
901
 *	We should only consider resume_device.
L
Linus Torvalds 已提交
902 903 904 905 906 907 908 909 910 911 912 913 914 915 916 917 918 919
 */

static int enough_swap(void)
{
	struct sysinfo i;

	si_swapinfo(&i);
	if (i.freeswap < (nr_copy_pages + PAGES_FOR_IO))  {
		pr_debug("swsusp: Not enough swap. Need %ld\n",i.freeswap);
		return 0;
	}
	return 1;
}

static int swsusp_alloc(void)
{
	int error;

P
Pavel Machek 已提交
920 921 922
	pagedir_nosave = NULL;
	nr_copy_pages = calc_nr(nr_copy_pages);

L
Linus Torvalds 已提交
923 924 925 926 927 928 929 930 931 932 933 934 935 936 937 938 939 940 941 942 943 944 945 946 947 948 949 950 951 952 953 954 955 956 957 958 959 960 961 962 963 964 965
	pr_debug("suspend: (pages needed: %d + %d free: %d)\n",
		 nr_copy_pages, PAGES_FOR_IO, nr_free_pages());

	if (!enough_free_mem())
		return -ENOMEM;

	if (!enough_swap())
		return -ENOSPC;

	if (!(pagedir_save = alloc_pagedir(nr_copy_pages))) {
		printk(KERN_ERR "suspend: Allocating pagedir failed.\n");
		return -ENOMEM;
	}
	create_pbe_list(pagedir_save, nr_copy_pages);
	pagedir_nosave = pagedir_save;
	if ((error = alloc_image_pages())) {
		printk(KERN_ERR "suspend: Allocating image pages failed.\n");
		swsusp_free();
		return error;
	}

	nr_copy_pages_check = nr_copy_pages;
	return 0;
}

static int suspend_prepare_image(void)
{
	int error;

	pr_debug("swsusp: critical section: \n");
	if (save_highmem()) {
		printk(KERN_CRIT "Suspend machine: Not enough free pages for highmem\n");
		restore_highmem();
		return -ENOMEM;
	}

	drain_local_pages();
	count_data_pages();
	printk("swsusp: Need to copy %u pages\n", nr_copy_pages);

	error = swsusp_alloc();
	if (error)
		return error;
966 967

	/* During allocating of suspend pagedir, new cold pages may appear.
L
Linus Torvalds 已提交
968 969 970 971 972 973 974 975 976 977 978 979 980 981 982 983 984 985 986 987 988 989 990 991 992 993 994 995 996 997 998 999 1000 1001 1002 1003 1004 1005 1006 1007 1008 1009 1010 1011 1012 1013 1014 1015 1016 1017 1018 1019 1020 1021 1022 1023 1024 1025 1026
	 * Kill them.
	 */
	drain_local_pages();
	copy_data_pages();

	/*
	 * End of critical section. From now on, we can write to memory,
	 * but we should not touch disk. This specially means we must _not_
	 * touch swap space! Except we must write out our image of course.
	 */

	printk("swsusp: critical section/: done (%d pages copied)\n", nr_copy_pages );
	return 0;
}


/* It is important _NOT_ to umount filesystems at this point. We want
 * them synced (in case something goes wrong) but we DO not want to mark
 * filesystem clean: it is not. (And it does not matter, if we resume
 * correctly, we'll mark system clean, anyway.)
 */
int swsusp_write(void)
{
	int error;
	device_resume();
	lock_swapdevices();
	error = write_suspend_image();
	/* This will unlock ignored swap devices since writing is finished */
	lock_swapdevices();
	return error;

}


extern asmlinkage int swsusp_arch_suspend(void);
extern asmlinkage int swsusp_arch_resume(void);


asmlinkage int swsusp_save(void)
{
	return suspend_prepare_image();
}

int swsusp_suspend(void)
{
	int error;
	if ((error = arch_prepare_suspend()))
		return error;
	local_irq_disable();
	/* At this point, device_suspend() has been called, but *not*
	 * device_power_down(). We *must* device_power_down() now.
	 * Otherwise, drivers for some devices (e.g. interrupt controllers)
	 * become desynchronized with the actual state of the hardware
	 * at resume time, and evil weirdness ensues.
	 */
	if ((error = device_power_down(PMSG_FREEZE))) {
		local_irq_enable();
		return error;
	}
1027 1028 1029 1030 1031 1032 1033 1034

	if ((error = swsusp_swap_check())) {
		printk(KERN_ERR "swsusp: FATAL: cannot find swap device, try "
				"swapon -a!\n");
		local_irq_enable();
		return error;
	}

L
Linus Torvalds 已提交
1035 1036
	save_processor_state();
	if ((error = swsusp_arch_suspend()))
1037
		printk("Error %d suspending\n", error);
L
Linus Torvalds 已提交
1038 1039 1040 1041 1042 1043 1044 1045 1046 1047 1048 1049 1050 1051 1052 1053 1054 1055 1056 1057 1058 1059 1060 1061 1062 1063 1064 1065 1066 1067 1068 1069 1070 1071 1072 1073 1074 1075 1076 1077 1078 1079 1080 1081 1082 1083 1084 1085 1086 1087 1088 1089 1090 1091 1092 1093 1094 1095
	/* Restore control flow magically appears here */
	restore_processor_state();
	BUG_ON (nr_copy_pages_check != nr_copy_pages);
	restore_highmem();
	device_power_up();
	local_irq_enable();
	return error;
}

int swsusp_resume(void)
{
	int error;
	local_irq_disable();
	if (device_power_down(PMSG_FREEZE))
		printk(KERN_ERR "Some devices failed to power down, very bad\n");
	/* We'll ignore saved state, but this gets preempt count (etc) right */
	save_processor_state();
	error = swsusp_arch_resume();
	/* Code below is only ever reached in case of failure. Otherwise
	 * execution continues at place where swsusp_arch_suspend was called
         */
	BUG_ON(!error);
	restore_processor_state();
	restore_highmem();
	device_power_up();
	local_irq_enable();
	return error;
}

/**
 *	On resume, for storing the PBE list and the image,
 *	we can only use memory pages that do not conflict with the pages
 *	which had been used before suspend.
 *
 *	We don't know which pages are usable until we allocate them.
 *
 *	Allocated but unusable (ie eaten) memory pages are linked together
 *	to create a list, so that we can free them easily
 *
 *	We could have used a type other than (void *)
 *	for this purpose, but ...
 */
static void **eaten_memory = NULL;

static inline void eat_page(void *page)
{
	void **c;

	c = eaten_memory;
	eaten_memory = page;
	*eaten_memory = c;
}

static unsigned long get_usable_page(unsigned gfp_mask)
{
	unsigned long m;

	m = get_zeroed_page(gfp_mask);
1096
	while (!PageNosaveFree(virt_to_page(m))) {
L
Linus Torvalds 已提交
1097 1098 1099 1100 1101 1102 1103 1104 1105 1106 1107 1108 1109 1110 1111 1112 1113 1114 1115 1116 1117 1118 1119 1120 1121 1122 1123 1124 1125 1126 1127 1128 1129 1130 1131 1132 1133 1134 1135 1136 1137 1138 1139 1140 1141 1142 1143 1144 1145 1146 1147 1148 1149 1150 1151 1152 1153 1154 1155 1156 1157 1158 1159 1160 1161 1162 1163 1164 1165 1166 1167
		eat_page((void *)m);
		m = get_zeroed_page(gfp_mask);
		if (!m)
			break;
	}
	return m;
}

static void free_eaten_memory(void)
{
	unsigned long m;
	void **c;
	int i = 0;

	c = eaten_memory;
	while (c) {
		m = (unsigned long)c;
		c = *c;
		free_page(m);
		i++;
	}
	eaten_memory = NULL;
	pr_debug("swsusp: %d unused pages freed\n", i);
}

/**
 *	check_pagedir - We ensure here that pages that the PBEs point to
 *	won't collide with pages where we're going to restore from the loaded
 *	pages later
 */

static int check_pagedir(struct pbe *pblist)
{
	struct pbe *p;

	/* This is necessary, so that we can free allocated pages
	 * in case of failure
	 */
	for_each_pbe (p, pblist)
		p->address = 0UL;

	for_each_pbe (p, pblist) {
		p->address = get_usable_page(GFP_ATOMIC);
		if (!p->address)
			return -ENOMEM;
	}
	return 0;
}

/**
 *	swsusp_pagedir_relocate - It is possible, that some memory pages
 *	occupied by the list of PBEs collide with pages where we're going to
 *	restore from the loaded pages later.  We relocate them here.
 */

static struct pbe * swsusp_pagedir_relocate(struct pbe *pblist)
{
	struct zone *zone;
	unsigned long zone_pfn;
	struct pbe *pbpage, *tail, *p;
	void *m;
	int rel = 0, error = 0;

	if (!pblist) /* a sanity check */
		return NULL;

	pr_debug("swsusp: Relocating pagedir (%lu pages to check)\n",
			swsusp_info.pagedir_pages);

	/* Set page flags */

1168
	for_each_zone (zone) {
L
Linus Torvalds 已提交
1169 1170 1171 1172 1173 1174 1175 1176 1177 1178 1179 1180 1181 1182 1183
        	for (zone_pfn = 0; zone_pfn < zone->spanned_pages; ++zone_pfn)
                	SetPageNosaveFree(pfn_to_page(zone_pfn +
					zone->zone_start_pfn));
	}

	/* Clear orig addresses */

	for_each_pbe (p, pblist)
		ClearPageNosaveFree(virt_to_page(p->orig_address));

	tail = pblist + PB_PAGE_SKIP;

	/* Relocate colliding pages */

	for_each_pb_page (pbpage, pblist) {
1184
		if (!PageNosaveFree(virt_to_page((unsigned long)pbpage))) {
L
Linus Torvalds 已提交
1185 1186 1187 1188 1189 1190 1191 1192 1193 1194 1195 1196 1197 1198 1199 1200 1201 1202 1203 1204 1205 1206 1207 1208 1209 1210 1211 1212 1213 1214 1215 1216 1217 1218 1219 1220 1221
			m = (void *)get_usable_page(GFP_ATOMIC | __GFP_COLD);
			if (!m) {
				error = -ENOMEM;
				break;
			}
			memcpy(m, (void *)pbpage, PAGE_SIZE);
			if (pbpage == pblist)
				pblist = (struct pbe *)m;
			else
				tail->next = (struct pbe *)m;

			eat_page((void *)pbpage);
			pbpage = (struct pbe *)m;

			/* We have to link the PBEs again */

			for (p = pbpage; p < pbpage + PB_PAGE_SKIP; p++)
				if (p->next) /* needed to save the end */
					p->next = p + 1;

			rel++;
		}
		tail = pbpage + PB_PAGE_SKIP;
	}

	if (error) {
		printk("\nswsusp: Out of memory\n\n");
		free_pagedir(pblist);
		free_eaten_memory();
		pblist = NULL;
	}
	else
		printk("swsusp: Relocated %d pages\n", rel);

	return pblist;
}

1222
/*
L
Linus Torvalds 已提交
1223 1224 1225 1226 1227 1228 1229 1230 1231 1232 1233 1234 1235 1236 1237 1238 1239 1240 1241 1242 1243 1244 1245 1246 1247 1248 1249 1250 1251 1252 1253 1254 1255 1256 1257 1258 1259 1260 1261 1262 1263 1264 1265 1266 1267 1268 1269 1270 1271 1272 1273 1274 1275 1276 1277 1278 1279 1280 1281 1282 1283 1284 1285 1286 1287 1288 1289 1290 1291 1292 1293 1294 1295 1296 1297 1298 1299 1300 1301 1302 1303
 *	Using bio to read from swap.
 *	This code requires a bit more work than just using buffer heads
 *	but, it is the recommended way for 2.5/2.6.
 *	The following are to signal the beginning and end of I/O. Bios
 *	finish asynchronously, while we want them to happen synchronously.
 *	A simple atomic_t, and a wait loop take care of this problem.
 */

static atomic_t io_done = ATOMIC_INIT(0);

static int end_io(struct bio * bio, unsigned int num, int err)
{
	if (!test_bit(BIO_UPTODATE, &bio->bi_flags))
		panic("I/O error reading memory image");
	atomic_set(&io_done, 0);
	return 0;
}

static struct block_device * resume_bdev;

/**
 *	submit - submit BIO request.
 *	@rw:	READ or WRITE.
 *	@off	physical offset of page.
 *	@page:	page we're reading or writing.
 *
 *	Straight from the textbook - allocate and initialize the bio.
 *	If we're writing, make sure the page is marked as dirty.
 *	Then submit it and wait.
 */

static int submit(int rw, pgoff_t page_off, void * page)
{
	int error = 0;
	struct bio * bio;

	bio = bio_alloc(GFP_ATOMIC, 1);
	if (!bio)
		return -ENOMEM;
	bio->bi_sector = page_off * (PAGE_SIZE >> 9);
	bio_get(bio);
	bio->bi_bdev = resume_bdev;
	bio->bi_end_io = end_io;

	if (bio_add_page(bio, virt_to_page(page), PAGE_SIZE, 0) < PAGE_SIZE) {
		printk("swsusp: ERROR: adding page to bio at %ld\n",page_off);
		error = -EFAULT;
		goto Done;
	}

	if (rw == WRITE)
		bio_set_pages_dirty(bio);

	atomic_set(&io_done, 1);
	submit_bio(rw | (1 << BIO_RW_SYNC), bio);
	while (atomic_read(&io_done))
		yield();

 Done:
	bio_put(bio);
	return error;
}

static int bio_read_page(pgoff_t page_off, void * page)
{
	return submit(READ, page_off, page);
}

static int bio_write_page(pgoff_t page_off, void * page)
{
	return submit(WRITE, page_off, page);
}

/*
 * Sanity check if this image makes sense with this kernel/swap context
 * I really don't think that it's foolproof but more than nothing..
 */

static const char * sanity_check(void)
{
	dump_info();
1304
	if (swsusp_info.version_code != LINUX_VERSION_CODE)
L
Linus Torvalds 已提交
1305
		return "kernel version";
1306
	if (swsusp_info.num_physpages != num_physpages)
L
Linus Torvalds 已提交
1307 1308 1309 1310 1311 1312 1313 1314 1315
		return "memory size";
	if (strcmp(swsusp_info.uts.sysname,system_utsname.sysname))
		return "system type";
	if (strcmp(swsusp_info.uts.release,system_utsname.release))
		return "kernel release";
	if (strcmp(swsusp_info.uts.version,system_utsname.version))
		return "version";
	if (strcmp(swsusp_info.uts.machine,system_utsname.machine))
		return "machine";
L
Li Shaohua 已提交
1316
#if 0
L
Linus Torvalds 已提交
1317 1318
	if(swsusp_info.cpus != num_online_cpus())
		return "number of cpus";
L
Li Shaohua 已提交
1319
#endif
L
Linus Torvalds 已提交
1320 1321 1322 1323 1324 1325 1326 1327 1328 1329 1330 1331 1332 1333 1334 1335 1336 1337 1338 1339 1340 1341 1342 1343 1344 1345 1346 1347 1348 1349
	return NULL;
}


static int check_header(void)
{
	const char * reason = NULL;
	int error;

	if ((error = bio_read_page(swp_offset(swsusp_header.swsusp_info), &swsusp_info)))
		return error;

 	/* Is this same machine? */
	if ((reason = sanity_check())) {
		printk(KERN_ERR "swsusp: Resume mismatch: %s\n",reason);
		return -EPERM;
	}
	nr_copy_pages = swsusp_info.image_pages;
	return error;
}

static int check_sig(void)
{
	int error;

	memset(&swsusp_header, 0, sizeof(swsusp_header));
	if ((error = bio_read_page(0, &swsusp_header)))
		return error;
	if (!memcmp(SWSUSP_SIG, swsusp_header.sig, 10)) {
		memcpy(swsusp_header.sig, swsusp_header.orig_sig, 10);
1350 1351
		memcpy(key_iv, swsusp_header.key_iv, MAXKEY+MAXIV);
		memset(swsusp_header.key_iv, 0, MAXKEY+MAXIV);
L
Linus Torvalds 已提交
1352 1353 1354 1355 1356 1357 1358 1359 1360 1361 1362 1363 1364 1365 1366 1367 1368 1369 1370 1371 1372 1373 1374 1375 1376 1377 1378

		/*
		 * Reset swap signature now.
		 */
		error = bio_write_page(0, &swsusp_header);
	} else { 
		printk(KERN_ERR "swsusp: Suspend partition has wrong signature?\n");
		return -EINVAL;
	}
	if (!error)
		pr_debug("swsusp: Signature found, resuming\n");
	return error;
}

/**
 *	data_read - Read image pages from swap.
 *
 *	You do not need to check for overlaps, check_pagedir()
 *	already did that.
 */

static int data_read(struct pbe *pblist)
{
	struct pbe * p;
	int error = 0;
	int i = 0;
	int mod = swsusp_info.image_pages / 100;
1379 1380 1381 1382
	void *tfm;

	if ((error = crypto_init(0, &tfm)))
		return error;
L
Linus Torvalds 已提交
1383 1384 1385 1386 1387 1388 1389 1390 1391 1392 1393

	if (!mod)
		mod = 1;

	printk("swsusp: Reading image data (%lu pages):     ",
			swsusp_info.image_pages);

	for_each_pbe (p, pblist) {
		if (!(i % mod))
			printk("\b\b\b\b%3d%%", i / mod);

1394 1395
		if ((error = crypto_read(p, tfm))) {
			crypto_exit(tfm);
L
Linus Torvalds 已提交
1396
			return error;
1397
		}
L
Linus Torvalds 已提交
1398 1399 1400 1401

		i++;
	}
	printk("\b\b\b\bdone\n");
1402
	crypto_exit(tfm);
L
Linus Torvalds 已提交
1403 1404 1405 1406 1407 1408 1409 1410 1411 1412 1413 1414 1415 1416 1417 1418 1419 1420 1421 1422 1423 1424 1425 1426 1427 1428 1429 1430 1431 1432 1433 1434 1435 1436 1437 1438 1439 1440 1441 1442 1443 1444 1445 1446 1447 1448 1449 1450 1451 1452 1453 1454 1455 1456 1457 1458 1459 1460 1461 1462 1463 1464 1465 1466 1467 1468 1469 1470 1471 1472 1473 1474 1475 1476 1477 1478 1479 1480 1481 1482 1483 1484 1485 1486 1487 1488 1489 1490 1491 1492 1493 1494 1495 1496 1497 1498 1499 1500 1501 1502 1503 1504 1505 1506 1507 1508 1509 1510 1511 1512 1513 1514 1515 1516 1517 1518 1519 1520 1521 1522 1523 1524 1525 1526 1527 1528 1529
	return error;
}

/**
 *	read_pagedir - Read page backup list pages from swap
 */

static int read_pagedir(struct pbe *pblist)
{
	struct pbe *pbpage, *p;
	unsigned i = 0;
	int error;

	if (!pblist)
		return -EFAULT;

	printk("swsusp: Reading pagedir (%lu pages)\n",
			swsusp_info.pagedir_pages);

	for_each_pb_page (pbpage, pblist) {
		unsigned long offset = swp_offset(swsusp_info.pagedir[i++]);

		error = -EFAULT;
		if (offset) {
			p = (pbpage + PB_PAGE_SKIP)->next;
			error = bio_read_page(offset, (void *)pbpage);
			(pbpage + PB_PAGE_SKIP)->next = p;
		}
		if (error)
			break;
	}

	if (error)
		free_page((unsigned long)pblist);

	BUG_ON(i != swsusp_info.pagedir_pages);

	return error;
}


static int check_suspend_image(void)
{
	int error = 0;

	if ((error = check_sig()))
		return error;

	if ((error = check_header()))
		return error;

	return 0;
}

static int read_suspend_image(void)
{
	int error = 0;
	struct pbe *p;

	if (!(p = alloc_pagedir(nr_copy_pages)))
		return -ENOMEM;

	if ((error = read_pagedir(p)))
		return error;

	create_pbe_list(p, nr_copy_pages);

	if (!(pagedir_nosave = swsusp_pagedir_relocate(p)))
		return -ENOMEM;

	/* Allocate memory for the image and read the data from swap */

	error = check_pagedir(pagedir_nosave);
	free_eaten_memory();
	if (!error)
		error = data_read(pagedir_nosave);

	if (error) { /* We fail cleanly */
		for_each_pbe (p, pagedir_nosave)
			if (p->address) {
				free_page(p->address);
				p->address = 0UL;
			}
		free_pagedir(pagedir_nosave);
	}
	return error;
}

/**
 *      swsusp_check - Check for saved image in swap
 */

int swsusp_check(void)
{
	int error;

	resume_bdev = open_by_devnum(swsusp_resume_device, FMODE_READ);
	if (!IS_ERR(resume_bdev)) {
		set_blocksize(resume_bdev, PAGE_SIZE);
		error = check_suspend_image();
		if (error)
		    blkdev_put(resume_bdev);
	} else
		error = PTR_ERR(resume_bdev);

	if (!error)
		pr_debug("swsusp: resume file found\n");
	else
		pr_debug("swsusp: Error %d check for resume file\n", error);
	return error;
}

/**
 *	swsusp_read - Read saved image from swap.
 */

int swsusp_read(void)
{
	int error;

	if (IS_ERR(resume_bdev)) {
		pr_debug("swsusp: block device not initialised\n");
		return PTR_ERR(resume_bdev);
	}

	error = read_suspend_image();
	blkdev_put(resume_bdev);
1530
	memset(key_iv, 0, MAXKEY+MAXIV);
L
Linus Torvalds 已提交
1531 1532 1533 1534 1535 1536 1537 1538 1539 1540 1541 1542 1543 1544 1545 1546 1547 1548 1549 1550 1551

	if (!error)
		pr_debug("swsusp: Reading resume file was successful\n");
	else
		pr_debug("swsusp: Error %d resuming\n", error);
	return error;
}

/**
 *	swsusp_close - close swap device.
 */

void swsusp_close(void)
{
	if (IS_ERR(resume_bdev)) {
		pr_debug("swsusp: block device not initialised\n");
		return;
	}

	blkdev_put(resume_bdev);
}