summaryrefslogtreecommitdiffstats
path: root/arch/x86/crypto/serpent_sse2_glue.c
blob: 5520c7522200f39fe0b8888c5975764b97117cb1 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
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
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
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
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
269
270
271
272
273
274
275
276
277
278
279
280
281
282
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
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
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
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
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
484
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
519
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
548
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
622
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
697
698
699
700
701
702
703
704
705
706
707
708
709
710
711
712
713
714
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
740
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
841
842
843
844
845
846
847
848
849
850
851
852
853
854
855
856
857
858
859
860
861
862
863
864
865
866
867
868
869
870
871
872
873
874
875
876
877
878
879
880
881
882
883
884
885
886
887
888
889
890
891
892
893
894
895
896
897
898
899
900
901
902
903
904
905
906
907
908
909
910
911
912
913
914
915
916
917
918
919
920
921
922
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
966
967
968
969
970
971
972
973
974
975
976
977
978
979
980
981
982
983
984
985
986
987
988
989
/*
 * Glue Code for SSE2 assembler versions of Serpent Cipher
 *
 * Copyright (c) 2011 Jussi Kivilinna <jussi.kivilinna@mbnet.fi>
 *
 * Glue code based on aesni-intel_glue.c by:
 *  Copyright (C) 2008, Intel Corp.
 *    Author: Huang Ying <ying.huang@intel.com>
 *
 * CBC & ECB parts based on code (crypto/cbc.c,ecb.c) by:
 *   Copyright (c) 2006 Herbert Xu <herbert@gondor.apana.org.au>
 * CTR part based on code (crypto/ctr.c) by:
 *   (C) Copyright IBM Corp. 2007 - Joy Latten <latten@us.ibm.com>
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; either version 2 of the License, or
 * (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307
 * USA
 *
 */

#include <linux/module.h>
#include <linux/hardirq.h>
#include <linux/types.h>
#include <linux/crypto.h>
#include <linux/err.h>
#include <crypto/algapi.h>
#include <crypto/serpent.h>
#include <crypto/cryptd.h>
#include <crypto/b128ops.h>
#include <crypto/ctr.h>
#include <crypto/lrw.h>
#include <crypto/xts.h>
#include <asm/i387.h>
#include <asm/serpent.h>
#include <crypto/scatterwalk.h>
#include <linux/workqueue.h>
#include <linux/spinlock.h>

struct async_serpent_ctx {
	struct cryptd_ablkcipher *cryptd_tfm;
};

static inline bool serpent_fpu_begin(bool fpu_enabled, unsigned int nbytes)
{
	if (fpu_enabled)
		return true;

	/* SSE2 is only used when chunk to be processed is large enough, so
	 * do not enable FPU until it is necessary.
	 */
	if (nbytes < SERPENT_BLOCK_SIZE * SERPENT_PARALLEL_BLOCKS)
		return false;

	kernel_fpu_begin();
	return true;
}

static inline void serpent_fpu_end(bool fpu_enabled)
{
	if (fpu_enabled)
		kernel_fpu_end();
}

static int ecb_crypt(struct blkcipher_desc *desc, struct blkcipher_walk *walk,
		     bool enc)
{
	bool fpu_enabled = false;
	struct serpent_ctx *ctx = crypto_blkcipher_ctx(desc->tfm);
	const unsigned int bsize = SERPENT_BLOCK_SIZE;
	unsigned int nbytes;
	int err;

	err = blkcipher_walk_virt(desc, walk);
	desc->flags &= ~CRYPTO_TFM_REQ_MAY_SLEEP;

	while ((nbytes = walk->nbytes)) {
		u8 *wsrc = walk->src.virt.addr;
		u8 *wdst = walk->dst.virt.addr;

		fpu_enabled = serpent_fpu_begin(fpu_enabled, nbytes);

		/* Process multi-block batch */
		if (nbytes >= bsize * SERPENT_PARALLEL_BLOCKS) {
			do {
				if (enc)
					serpent_enc_blk_xway(ctx, wdst, wsrc);
				else
					serpent_dec_blk_xway(ctx, wdst, wsrc);

				wsrc += bsize * SERPENT_PARALLEL_BLOCKS;
				wdst += bsize * SERPENT_PARALLEL_BLOCKS;
				nbytes -= bsize * SERPENT_PARALLEL_BLOCKS;
			} while (nbytes >= bsize * SERPENT_PARALLEL_BLOCKS);

			if (nbytes < bsize)
				goto done;
		}

		/* Handle leftovers */
		do {
			if (enc)
				__serpent_encrypt(ctx, wdst, wsrc);
			else
				__serpent_decrypt(ctx, wdst, wsrc);

			wsrc += bsize;
			wdst += bsize;
			nbytes -= bsize;
		} while (nbytes >= bsize);

done:
		err = blkcipher_walk_done(desc, walk, nbytes);
	}

	serpent_fpu_end(fpu_enabled);
	return err;
}

static int ecb_encrypt(struct blkcipher_desc *desc, struct scatterlist *dst,
		       struct scatterlist *src, unsigned int nbytes)
{
	struct blkcipher_walk walk;

	blkcipher_walk_init(&walk, dst, src, nbytes);
	return ecb_crypt(desc, &walk, true);
}

static int ecb_decrypt(struct blkcipher_desc *desc, struct scatterlist *dst,
		       struct scatterlist *src, unsigned int nbytes)
{
	struct blkcipher_walk walk;

	blkcipher_walk_init(&walk, dst, src, nbytes);
	return ecb_crypt(desc, &walk, false);
}

static unsigned int __cbc_encrypt(struct blkcipher_desc *desc,
				  struct blkcipher_walk *walk)
{
	struct serpent_ctx *ctx = crypto_blkcipher_ctx(desc->tfm);
	const unsigned int bsize = SERPENT_BLOCK_SIZE;
	unsigned int nbytes = walk->nbytes;
	u128 *src = (u128 *)walk->src.virt.addr;
	u128 *dst = (u128 *)walk->dst.virt.addr;
	u128 *iv = (u128 *)walk->iv;

	do {
		u128_xor(dst, src, iv);
		__serpent_encrypt(ctx, (u8 *)dst, (u8 *)dst);
		iv = dst;

		src += 1;
		dst += 1;
		nbytes -= bsize;
	} while (nbytes >= bsize);

	u128_xor((u128 *)walk->iv, (u128 *)walk->iv, iv);
	return nbytes;
}

static int cbc_encrypt(struct blkcipher_desc *desc, struct scatterlist *dst,
		       struct scatterlist *src, unsigned int nbytes)
{
	struct blkcipher_walk walk;
	int err;

	blkcipher_walk_init(&walk, dst, src, nbytes);
	err = blkcipher_walk_virt(desc, &walk);

	while ((nbytes = walk.nbytes)) {
		nbytes = __cbc_encrypt(desc, &walk);
		err = blkcipher_walk_done(desc, &walk, nbytes);
	}

	return err;
}

static unsigned int __cbc_decrypt(struct blkcipher_desc *desc,
				  struct blkcipher_walk *walk)
{
	struct serpent_ctx *ctx = crypto_blkcipher_ctx(desc->tfm);
	const unsigned int bsize = SERPENT_BLOCK_SIZE;
	unsigned int nbytes = walk->nbytes;
	u128 *src = (u128 *)walk->src.virt.addr;
	u128 *dst = (u128 *)walk->dst.virt.addr;
	u128 ivs[SERPENT_PARALLEL_BLOCKS - 1];
	u128 last_iv;
	int i;

	/* Start of the last block. */
	src += nbytes / bsize - 1;
	dst += nbytes / bsize - 1;

	last_iv = *src;

	/* Process multi-block batch */
	if (nbytes >= bsize * SERPENT_PARALLEL_BLOCKS) {
		do {
			nbytes -= bsize * (SERPENT_PARALLEL_BLOCKS - 1);
			src -= SERPENT_PARALLEL_BLOCKS - 1;
			dst -= SERPENT_PARALLEL_BLOCKS - 1;

			for (i = 0; i < SERPENT_PARALLEL_BLOCKS - 1; i++)
				ivs[i] = src[i];

			serpent_dec_blk_xway(ctx, (u8 *)dst, (u8 *)src);

			for (i = 0; i < SERPENT_PARALLEL_BLOCKS - 1; i++)
				u128_xor(dst + (i + 1), dst + (i + 1), ivs + i);

			nbytes -= bsize;
			if (nbytes < bsize)
				goto done;

			u128_xor(dst, dst, src - 1);
			src -= 1;
			dst -= 1;
		} while (nbytes >= bsize * SERPENT_PARALLEL_BLOCKS);

		if (nbytes < bsize)
			goto done;
	}

	/* Handle leftovers */
	for (;;) {
		__serpent_decrypt(ctx, (u8 *)dst, (u8 *)src);

		nbytes -= bsize;
		if (nbytes < bsize)
			break;

		u128_xor(dst, dst, src - 1);
		src -= 1;
		dst -= 1;
	}

done:
	u128_xor(dst, dst, (u128 *)walk->iv);
	*(u128 *)walk->iv = last_iv;

	return nbytes;
}

static int cbc_decrypt(struct blkcipher_desc *desc, struct scatterlist *dst,
		       struct scatterlist *src, unsigned int nbytes)
{
	bool fpu_enabled = false;
	struct blkcipher_walk walk;
	int err;

	blkcipher_walk_init(&walk, dst, src, nbytes);
	err = blkcipher_walk_virt(desc, &walk);
	desc->flags &= ~CRYPTO_TFM_REQ_MAY_SLEEP;

	while ((nbytes = walk.nbytes)) {
		fpu_enabled = serpent_fpu_begin(fpu_enabled, nbytes);
		nbytes = __cbc_decrypt(desc, &walk);
		err = blkcipher_walk_done(desc, &walk, nbytes);
	}

	serpent_fpu_end(fpu_enabled);
	return err;
}

static inline void u128_to_be128(be128 *dst, const u128 *src)
{
	dst->a = cpu_to_be64(src->a);
	dst->b = cpu_to_be64(src->b);
}

static inline void be128_to_u128(u128 *dst, const be128 *src)
{
	dst->a = be64_to_cpu(src->a);
	dst->b = be64_to_cpu(src->b);
}

static inline void u128_inc(u128 *i)
{
	i->b++;
	if (!i->b)
		i->a++;
}

static void ctr_crypt_final(struct blkcipher_desc *desc,
			    struct blkcipher_walk *walk)
{
	struct serpent_ctx *ctx = crypto_blkcipher_ctx(desc->tfm);
	u8 *ctrblk = walk->iv;
	u8 keystream[SERPENT_BLOCK_SIZE];
	u8 *src = walk->src.virt.addr;
	u8 *dst = walk->dst.virt.addr;
	unsigned int nbytes = walk->nbytes;

	__serpent_encrypt(ctx, keystream, ctrblk);
	crypto_xor(keystream, src, nbytes);
	memcpy(dst, keystream, nbytes);

	crypto_inc(ctrblk, SERPENT_BLOCK_SIZE);
}

static unsigned int __ctr_crypt(struct blkcipher_desc *desc,
				struct blkcipher_walk *walk)
{
	struct serpent_ctx *ctx = crypto_blkcipher_ctx(desc->tfm);
	const unsigned int bsize = SERPENT_BLOCK_SIZE;
	unsigned int nbytes = walk->nbytes;
	u128 *src = (u128 *)walk->src.virt.addr;
	u128 *dst = (u128 *)walk->dst.virt.addr;
	u128 ctrblk;
	be128 ctrblocks[SERPENT_PARALLEL_BLOCKS];
	int i;

	be128_to_u128(&ctrblk, (be128 *)walk->iv);

	/* Process multi-block batch */
	if (nbytes >= bsize * SERPENT_PARALLEL_BLOCKS) {
		do {
			/* create ctrblks for parallel encrypt */
			for (i = 0; i < SERPENT_PARALLEL_BLOCKS; i++) {
				if (dst != src)
					dst[i] = src[i];

				u128_to_be128(&ctrblocks[i], &ctrblk);
				u128_inc(&ctrblk);
			}

			serpent_enc_blk_xway_xor(ctx, (u8 *)dst,
						 (u8 *)ctrblocks);

			src += SERPENT_PARALLEL_BLOCKS;
			dst += SERPENT_PARALLEL_BLOCKS;
			nbytes -= bsize * SERPENT_PARALLEL_BLOCKS;
		} while (nbytes >= bsize * SERPENT_PARALLEL_BLOCKS);

		if (nbytes < bsize)
			goto done;
	}

	/* Handle leftovers */
	do {
		if (dst != src)
			*dst = *src;

		u128_to_be128(&ctrblocks[0], &ctrblk);
		u128_inc(&ctrblk);

		__serpent_encrypt(ctx, (u8 *)ctrblocks, (u8 *)ctrblocks);
		u128_xor(dst, dst, (u128 *)ctrblocks);

		src += 1;
		dst += 1;
		nbytes -= bsize;
	} while (nbytes >= bsize);

done:
	u128_to_be128((be128 *)walk->iv, &ctrblk);
	return nbytes;
}

static int ctr_crypt(struct blkcipher_desc *desc, struct scatterlist *dst,
		     struct scatterlist *src, unsigned int nbytes)
{
	bool fpu_enabled = false;
	struct blkcipher_walk walk;
	int err;

	blkcipher_walk_init(&walk, dst, src, nbytes);
	err = blkcipher_walk_virt_block(desc, &walk, SERPENT_BLOCK_SIZE);
	desc->flags &= ~CRYPTO_TFM_REQ_MAY_SLEEP;

	while ((nbytes = walk.nbytes) >= SERPENT_BLOCK_SIZE) {
		fpu_enabled = serpent_fpu_begin(fpu_enabled, nbytes);
		nbytes = __ctr_crypt(desc, &walk);
		err = blkcipher_walk_done(desc, &walk, nbytes);
	}

	serpent_fpu_end(fpu_enabled);

	if (walk.nbytes) {
		ctr_crypt_final(desc, &walk);
		err = blkcipher_walk_done(desc, &walk, 0);
	}

	return err;
}

struct crypt_priv {
	struct serpent_ctx *ctx;
	bool fpu_enabled;
};

static void encrypt_callback(void *priv, u8 *srcdst, unsigned int nbytes)
{
	const unsigned int bsize = SERPENT_BLOCK_SIZE;
	struct crypt_priv *ctx = priv;
	int i;

	ctx->fpu_enabled = serpent_fpu_begin(ctx->fpu_enabled, nbytes);

	if (nbytes == bsize * SERPENT_PARALLEL_BLOCKS) {
		serpent_enc_blk_xway(ctx->ctx, srcdst, srcdst);
		return;
	}

	for (i = 0; i < nbytes / bsize; i++, srcdst += bsize)
		__serpent_encrypt(ctx->ctx, srcdst, srcdst);
}

static void decrypt_callback(void *priv, u8 *srcdst, unsigned int nbytes)
{
	const unsigned int bsize = SERPENT_BLOCK_SIZE;
	struct crypt_priv *ctx = priv;
	int i;

	ctx->fpu_enabled = serpent_fpu_begin(ctx->fpu_enabled, nbytes);

	if (nbytes == bsize * SERPENT_PARALLEL_BLOCKS) {
		serpent_dec_blk_xway(ctx->ctx, srcdst, srcdst);
		return;
	}

	for (i = 0; i < nbytes / bsize; i++, srcdst += bsize)
		__serpent_decrypt(ctx->ctx, srcdst, srcdst);
}

struct serpent_lrw_ctx {
	struct lrw_table_ctx lrw_table;
	struct serpent_ctx serpent_ctx;
};

static int lrw_serpent_setkey(struct crypto_tfm *tfm, const u8 *key,
			      unsigned int keylen)
{
	struct serpent_lrw_ctx *ctx = crypto_tfm_ctx(tfm);
	int err;

	err = __serpent_setkey(&ctx->serpent_ctx, key, keylen -
							SERPENT_BLOCK_SIZE);
	if (err)
		return err;

	return lrw_init_table(&ctx->lrw_table, key + keylen -
						SERPENT_BLOCK_SIZE);
}

static int lrw_encrypt(struct blkcipher_desc *desc, struct scatterlist *dst,
		       struct scatterlist *src, unsigned int nbytes)
{
	struct serpent_lrw_ctx *ctx = crypto_blkcipher_ctx(desc->tfm);
	be128 buf[SERPENT_PARALLEL_BLOCKS];
	struct crypt_priv crypt_ctx = {
		.ctx = &ctx->serpent_ctx,
		.fpu_enabled = false,
	};
	struct lrw_crypt_req req = {
		.tbuf = buf,
		.tbuflen = sizeof(buf),

		.table_ctx = &ctx->lrw_table,
		.crypt_ctx = &crypt_ctx,
		.crypt_fn = encrypt_callback,
	};
	int ret;

	desc->flags &= ~CRYPTO_TFM_REQ_MAY_SLEEP;
	ret = lrw_crypt(desc, dst, src, nbytes, &req);
	serpent_fpu_end(crypt_ctx.fpu_enabled);

	return ret;
}

static int lrw_decrypt(struct blkcipher_desc *desc, struct scatterlist *dst,
		       struct scatterlist *src, unsigned int nbytes)
{
	struct serpent_lrw_ctx *ctx = crypto_blkcipher_ctx(desc->tfm);
	be128 buf[SERPENT_PARALLEL_BLOCKS];
	struct crypt_priv crypt_ctx = {
		.ctx = &ctx->serpent_ctx,
		.fpu_enabled = false,
	};
	struct lrw_crypt_req req = {
		.tbuf = buf,
		.tbuflen = sizeof(buf),

		.table_ctx = &ctx->lrw_table,
		.crypt_ctx = &crypt_ctx,
		.crypt_fn = decrypt_callback,
	};
	int ret;

	desc->flags &= ~CRYPTO_TFM_REQ_MAY_SLEEP;
	ret = lrw_crypt(desc, dst, src, nbytes, &req);
	serpent_fpu_end(crypt_ctx.fpu_enabled);

	return ret;
}

static void lrw_exit_tfm(struct crypto_tfm *tfm)
{
	struct serpent_lrw_ctx *ctx = crypto_tfm_ctx(tfm);

	lrw_free_table(&ctx->lrw_table);
}

struct serpent_xts_ctx {
	struct serpent_ctx tweak_ctx;
	struct serpent_ctx crypt_ctx;
};

static int xts_serpent_setkey(struct crypto_tfm *tfm, const u8 *key,
			      unsigned int keylen)
{
	struct serpent_xts_ctx *ctx = crypto_tfm_ctx(tfm);
	u32 *flags = &tfm->crt_flags;
	int err;

	/* key consists of keys of equal size concatenated, therefore
	 * the length must be even
	 */
	if (keylen % 2) {
		*flags |= CRYPTO_TFM_RES_BAD_KEY_LEN;
		return -EINVAL;
	}

	/* first half of xts-key is for crypt */
	err = __serpent_setkey(&ctx->crypt_ctx, key, keylen / 2);
	if (err)
		return err;

	/* second half of xts-key is for tweak */
	return __serpent_setkey(&ctx->tweak_ctx, key + keylen / 2, keylen / 2);
}

static int xts_encrypt(struct blkcipher_desc *desc, struct scatterlist *dst,
		       struct scatterlist *src, unsigned int nbytes)
{
	struct serpent_xts_ctx *ctx = crypto_blkcipher_ctx(desc->tfm);
	be128 buf[SERPENT_PARALLEL_BLOCKS];
	struct crypt_priv crypt_ctx = {
		.ctx = &ctx->crypt_ctx,
		.fpu_enabled = false,
	};
	struct xts_crypt_req req = {
		.tbuf = buf,
		.tbuflen = sizeof(buf),

		.tweak_ctx = &ctx->tweak_ctx,
		.tweak_fn = XTS_TWEAK_CAST(__serpent_encrypt),
		.crypt_ctx = &crypt_ctx,
		.crypt_fn = encrypt_callback,
	};
	int ret;

	desc->flags &= ~CRYPTO_TFM_REQ_MAY_SLEEP;
	ret = xts_crypt(desc, dst, src, nbytes, &req);
	serpent_fpu_end(crypt_ctx.fpu_enabled);

	return ret;
}

static int xts_decrypt(struct blkcipher_desc *desc, struct scatterlist *dst,
		       struct scatterlist *src, unsigned int nbytes)
{
	struct serpent_xts_ctx *ctx = crypto_blkcipher_ctx(desc->tfm);
	be128 buf[SERPENT_PARALLEL_BLOCKS];
	struct crypt_priv crypt_ctx = {
		.ctx = &ctx->crypt_ctx,
		.fpu_enabled = false,
	};
	struct xts_crypt_req req = {
		.tbuf = buf,
		.tbuflen = sizeof(buf),

		.tweak_ctx = &ctx->tweak_ctx,
		.tweak_fn = XTS_TWEAK_CAST(__serpent_encrypt),
		.crypt_ctx = &crypt_ctx,
		.crypt_fn = decrypt_callback,
	};
	int ret;

	desc->flags &= ~CRYPTO_TFM_REQ_MAY_SLEEP;
	ret = xts_crypt(desc, dst, src, nbytes, &req);
	serpent_fpu_end(crypt_ctx.fpu_enabled);

	return ret;
}

static int ablk_set_key(struct crypto_ablkcipher *tfm, const u8 *key,
			unsigned int key_len)
{
	struct async_serpent_ctx *ctx = crypto_ablkcipher_ctx(tfm);
	struct crypto_ablkcipher *child = &ctx->cryptd_tfm->base;
	int err;

	crypto_ablkcipher_clear_flags(child, CRYPTO_TFM_REQ_MASK);
	crypto_ablkcipher_set_flags(child, crypto_ablkcipher_get_flags(tfm)
				    & CRYPTO_TFM_REQ_MASK);
	err = crypto_ablkcipher_setkey(child, key, key_len);
	crypto_ablkcipher_set_flags(tfm, crypto_ablkcipher_get_flags(child)
				    & CRYPTO_TFM_RES_MASK);
	return err;
}

static int __ablk_encrypt(struct ablkcipher_request *req)
{
	struct crypto_ablkcipher *tfm = crypto_ablkcipher_reqtfm(req);
	struct async_serpent_ctx *ctx = crypto_ablkcipher_ctx(tfm);
	struct blkcipher_desc desc;

	desc.tfm = cryptd_ablkcipher_child(ctx->cryptd_tfm);
	desc.info = req->info;
	desc.flags = 0;

	return crypto_blkcipher_crt(desc.tfm)->encrypt(
		&desc, req->dst, req->src, req->nbytes);
}

static int ablk_encrypt(struct ablkcipher_request *req)
{
	struct crypto_ablkcipher *tfm = crypto_ablkcipher_reqtfm(req);
	struct async_serpent_ctx *ctx = crypto_ablkcipher_ctx(tfm);

	if (!irq_fpu_usable()) {
		struct ablkcipher_request *cryptd_req =
			ablkcipher_request_ctx(req);

		memcpy(cryptd_req, req, sizeof(*req));
		ablkcipher_request_set_tfm(cryptd_req, &ctx->cryptd_tfm->base);

		return crypto_ablkcipher_encrypt(cryptd_req);
	} else {
		return __ablk_encrypt(req);
	}
}

static int ablk_decrypt(struct ablkcipher_request *req)
{
	struct crypto_ablkcipher *tfm = crypto_ablkcipher_reqtfm(req);
	struct async_serpent_ctx *ctx = crypto_ablkcipher_ctx(tfm);

	if (!irq_fpu_usable()) {
		struct ablkcipher_request *cryptd_req =
			ablkcipher_request_ctx(req);

		memcpy(cryptd_req, req, sizeof(*req));
		ablkcipher_request_set_tfm(cryptd_req, &ctx->cryptd_tfm->base);

		return crypto_ablkcipher_decrypt(cryptd_req);
	} else {
		struct blkcipher_desc desc;

		desc.tfm = cryptd_ablkcipher_child(ctx->cryptd_tfm);
		desc.info = req->info;
		desc.flags = 0;

		return crypto_blkcipher_crt(desc.tfm)->decrypt(
			&desc, req->dst, req->src, req->nbytes);
	}
}

static void ablk_exit(struct crypto_tfm *tfm)
{
	struct async_serpent_ctx *ctx = crypto_tfm_ctx(tfm);

	cryptd_free_ablkcipher(ctx->cryptd_tfm);
}

static void ablk_init_common(struct crypto_tfm *tfm,
			     struct cryptd_ablkcipher *cryptd_tfm)
{
	struct async_serpent_ctx *ctx = crypto_tfm_ctx(tfm);

	ctx->cryptd_tfm = cryptd_tfm;
	tfm->crt_ablkcipher.reqsize = sizeof(struct ablkcipher_request) +
		crypto_ablkcipher_reqsize(&cryptd_tfm->base);
}

static int ablk_ecb_init(struct crypto_tfm *tfm)
{
	struct cryptd_ablkcipher *cryptd_tfm;

	cryptd_tfm = cryptd_alloc_ablkcipher("__driver-ecb-serpent-sse2", 0, 0);
	if (IS_ERR(cryptd_tfm))
		return PTR_ERR(cryptd_tfm);
	ablk_init_common(tfm, cryptd_tfm);
	return 0;
}

static int ablk_cbc_init(struct crypto_tfm *tfm)
{
	struct cryptd_ablkcipher *cryptd_tfm;

	cryptd_tfm = cryptd_alloc_ablkcipher("__driver-cbc-serpent-sse2", 0, 0);
	if (IS_ERR(cryptd_tfm))
		return PTR_ERR(cryptd_tfm);
	ablk_init_common(tfm, cryptd_tfm);
	return 0;
}

static int ablk_ctr_init(struct crypto_tfm *tfm)
{
	struct cryptd_ablkcipher *cryptd_tfm;

	cryptd_tfm = cryptd_alloc_ablkcipher("__driver-ctr-serpent-sse2", 0, 0);
	if (IS_ERR(cryptd_tfm))
		return PTR_ERR(cryptd_tfm);
	ablk_init_common(tfm, cryptd_tfm);
	return 0;
}

static int ablk_lrw_init(struct crypto_tfm *tfm)
{
	struct cryptd_ablkcipher *cryptd_tfm;

	cryptd_tfm = cryptd_alloc_ablkcipher("__driver-lrw-serpent-sse2", 0, 0);
	if (IS_ERR(cryptd_tfm))
		return PTR_ERR(cryptd_tfm);
	ablk_init_common(tfm, cryptd_tfm);
	return 0;
}

static int ablk_xts_init(struct crypto_tfm *tfm)
{
	struct cryptd_ablkcipher *cryptd_tfm;

	cryptd_tfm = cryptd_alloc_ablkcipher("__driver-xts-serpent-sse2", 0, 0);
	if (IS_ERR(cryptd_tfm))
		return PTR_ERR(cryptd_tfm);
	ablk_init_common(tfm, cryptd_tfm);
	return 0;
}

static struct crypto_alg serpent_algs[10] = { {
	.cra_name		= "__ecb-serpent-sse2",
	.cra_driver_name	= "__driver-ecb-serpent-sse2",
	.cra_priority		= 0,
	.cra_flags		= CRYPTO_ALG_TYPE_BLKCIPHER,
	.cra_blocksize		= SERPENT_BLOCK_SIZE,
	.cra_ctxsize		= sizeof(struct serpent_ctx),
	.cra_alignmask		= 0,
	.cra_type		= &crypto_blkcipher_type,
	.cra_module		= THIS_MODULE,
	.cra_list		= LIST_HEAD_INIT(serpent_algs[0].cra_list),
	.cra_u = {
		.blkcipher = {
			.min_keysize	= SERPENT_MIN_KEY_SIZE,
			.max_keysize	= SERPENT_MAX_KEY_SIZE,
			.setkey		= serpent_setkey,
			.encrypt	= ecb_encrypt,
			.decrypt	= ecb_decrypt,
		},
	},
}, {
	.cra_name		= "__cbc-serpent-sse2",
	.cra_driver_name	= "__driver-cbc-serpent-sse2",
	.cra_priority		= 0,
	.cra_flags		= CRYPTO_ALG_TYPE_BLKCIPHER,
	.cra_blocksize		= SERPENT_BLOCK_SIZE,
	.cra_ctxsize		= sizeof(struct serpent_ctx),
	.cra_alignmask		= 0,
	.cra_type		= &crypto_blkcipher_type,
	.cra_module		= THIS_MODULE,
	.cra_list		= LIST_HEAD_INIT(serpent_algs[1].cra_list),
	.cra_u = {
		.blkcipher = {
			.min_keysize	= SERPENT_MIN_KEY_SIZE,
			.max_keysize	= SERPENT_MAX_KEY_SIZE,
			.setkey		= serpent_setkey,
			.encrypt	= cbc_encrypt,
			.decrypt	= cbc_decrypt,
		},
	},
}, {
	.cra_name		= "__ctr-serpent-sse2",
	.cra_driver_name	= "__driver-ctr-serpent-sse2",
	.cra_priority		= 0,
	.cra_flags		= CRYPTO_ALG_TYPE_BLKCIPHER,
	.cra_blocksize		= 1,
	.cra_ctxsize		= sizeof(struct serpent_ctx),
	.cra_alignmask		= 0,
	.cra_type		= &crypto_blkcipher_type,
	.cra_module		= THIS_MODULE,
	.cra_list		= LIST_HEAD_INIT(serpent_algs[2].cra_list),
	.cra_u = {
		.blkcipher = {
			.min_keysize	= SERPENT_MIN_KEY_SIZE,
			.max_keysize	= SERPENT_MAX_KEY_SIZE,
			.ivsize		= SERPENT_BLOCK_SIZE,
			.setkey		= serpent_setkey,
			.encrypt	= ctr_crypt,
			.decrypt	= ctr_crypt,
		},
	},
}, {
	.cra_name		= "__lrw-serpent-sse2",
	.cra_driver_name	= "__driver-lrw-serpent-sse2",
	.cra_priority		= 0,
	.cra_flags		= CRYPTO_ALG_TYPE_BLKCIPHER,
	.cra_blocksize		= SERPENT_BLOCK_SIZE,
	.cra_ctxsize		= sizeof(struct serpent_lrw_ctx),
	.cra_alignmask		= 0,
	.cra_type		= &crypto_blkcipher_type,
	.cra_module		= THIS_MODULE,
	.cra_list		= LIST_HEAD_INIT(serpent_algs[3].cra_list),
	.cra_exit		= lrw_exit_tfm,
	.cra_u = {
		.blkcipher = {
			.min_keysize	= SERPENT_MIN_KEY_SIZE +
					  SERPENT_BLOCK_SIZE,
			.max_keysize	= SERPENT_MAX_KEY_SIZE +
					  SERPENT_BLOCK_SIZE,
			.ivsize		= SERPENT_BLOCK_SIZE,
			.setkey		= lrw_serpent_setkey,
			.encrypt	= lrw_encrypt,
			.decrypt	= lrw_decrypt,
		},
	},
}, {
	.cra_name		= "__xts-serpent-sse2",
	.cra_driver_name	= "__driver-xts-serpent-sse2",
	.cra_priority		= 0,
	.cra_flags		= CRYPTO_ALG_TYPE_BLKCIPHER,
	.cra_blocksize		= SERPENT_BLOCK_SIZE,
	.cra_ctxsize		= sizeof(struct serpent_xts_ctx),
	.cra_alignmask		= 0,
	.cra_type		= &crypto_blkcipher_type,
	.cra_module		= THIS_MODULE,
	.cra_list		= LIST_HEAD_INIT(serpent_algs[4].cra_list),
	.cra_u = {
		.blkcipher = {
			.min_keysize	= SERPENT_MIN_KEY_SIZE * 2,
			.max_keysize	= SERPENT_MAX_KEY_SIZE * 2,
			.ivsize		= SERPENT_BLOCK_SIZE,
			.setkey		= xts_serpent_setkey,
			.encrypt	= xts_encrypt,
			.decrypt	= xts_decrypt,
		},
	},
}, {
	.cra_name		= "ecb(serpent)",
	.cra_driver_name	= "ecb-serpent-sse2",
	.cra_priority		= 400,
	.cra_flags		= CRYPTO_ALG_TYPE_ABLKCIPHER | CRYPTO_ALG_ASYNC,
	.cra_blocksize		= SERPENT_BLOCK_SIZE,
	.cra_ctxsize		= sizeof(struct async_serpent_ctx),
	.cra_alignmask		= 0,
	.cra_type		= &crypto_ablkcipher_type,
	.cra_module		= THIS_MODULE,
	.cra_list		= LIST_HEAD_INIT(serpent_algs[5].cra_list),
	.cra_init		= ablk_ecb_init,
	.cra_exit		= ablk_exit,
	.cra_u = {
		.ablkcipher = {
			.min_keysize	= SERPENT_MIN_KEY_SIZE,
			.max_keysize	= SERPENT_MAX_KEY_SIZE,
			.setkey		= ablk_set_key,
			.encrypt	= ablk_encrypt,
			.decrypt	= ablk_decrypt,
		},
	},
}, {
	.cra_name		= "cbc(serpent)",
	.cra_driver_name	= "cbc-serpent-sse2",
	.cra_priority		= 400,
	.cra_flags		= CRYPTO_ALG_TYPE_ABLKCIPHER | CRYPTO_ALG_ASYNC,
	.cra_blocksize		= SERPENT_BLOCK_SIZE,
	.cra_ctxsize		= sizeof(struct async_serpent_ctx),
	.cra_alignmask		= 0,
	.cra_type		= &crypto_ablkcipher_type,
	.cra_module		= THIS_MODULE,
	.cra_list		= LIST_HEAD_INIT(serpent_algs[6].cra_list),
	.cra_init		= ablk_cbc_init,
	.cra_exit		= ablk_exit,
	.cra_u = {
		.ablkcipher = {
			.min_keysize	= SERPENT_MIN_KEY_SIZE,
			.max_keysize	= SERPENT_MAX_KEY_SIZE,
			.ivsize		= SERPENT_BLOCK_SIZE,
			.setkey		= ablk_set_key,
			.encrypt	= __ablk_encrypt,
			.decrypt	= ablk_decrypt,
		},
	},
}, {
	.cra_name		= "ctr(serpent)",
	.cra_driver_name	= "ctr-serpent-sse2",
	.cra_priority		= 400,
	.cra_flags		= CRYPTO_ALG_TYPE_ABLKCIPHER | CRYPTO_ALG_ASYNC,
	.cra_blocksize		= 1,
	.cra_ctxsize		= sizeof(struct async_serpent_ctx),
	.cra_alignmask		= 0,
	.cra_type		= &crypto_ablkcipher_type,
	.cra_module		= THIS_MODULE,
	.cra_list		= LIST_HEAD_INIT(serpent_algs[7].cra_list),
	.cra_init		= ablk_ctr_init,
	.cra_exit		= ablk_exit,
	.cra_u = {
		.ablkcipher = {
			.min_keysize	= SERPENT_MIN_KEY_SIZE,
			.max_keysize	= SERPENT_MAX_KEY_SIZE,
			.ivsize		= SERPENT_BLOCK_SIZE,
			.setkey		= ablk_set_key,
			.encrypt	= ablk_encrypt,
			.decrypt	= ablk_encrypt,
			.geniv		= "chainiv",
		},
	},
}, {
	.cra_name		= "lrw(serpent)",
	.cra_driver_name	= "lrw-serpent-sse2",
	.cra_priority		= 400,
	.cra_flags		= CRYPTO_ALG_TYPE_ABLKCIPHER | CRYPTO_ALG_ASYNC,
	.cra_blocksize		= SERPENT_BLOCK_SIZE,
	.cra_ctxsize		= sizeof(struct async_serpent_ctx),
	.cra_alignmask		= 0,
	.cra_type		= &crypto_ablkcipher_type,
	.cra_module		= THIS_MODULE,
	.cra_list		= LIST_HEAD_INIT(serpent_algs[8].cra_list),
	.cra_init		= ablk_lrw_init,
	.cra_exit		= ablk_exit,
	.cra_u = {
		.ablkcipher = {
			.min_keysize	= SERPENT_MIN_KEY_SIZE +
					  SERPENT_BLOCK_SIZE,
			.max_keysize	= SERPENT_MAX_KEY_SIZE +
					  SERPENT_BLOCK_SIZE,
			.ivsize		= SERPENT_BLOCK_SIZE,
			.setkey		= ablk_set_key,
			.encrypt	= ablk_encrypt,
			.decrypt	= ablk_decrypt,
		},
	},
}, {
	.cra_name		= "xts(serpent)",
	.cra_driver_name	= "xts-serpent-sse2",
	.cra_priority		= 400,
	.cra_flags		= CRYPTO_ALG_TYPE_ABLKCIPHER | CRYPTO_ALG_ASYNC,
	.cra_blocksize		= SERPENT_BLOCK_SIZE,
	.cra_ctxsize		= sizeof(struct async_serpent_ctx),
	.cra_alignmask		= 0,
	.cra_type		= &crypto_ablkcipher_type,
	.cra_module		= THIS_MODULE,
	.cra_list		= LIST_HEAD_INIT(serpent_algs[9].cra_list),
	.cra_init		= ablk_xts_init,
	.cra_exit		= ablk_exit,
	.cra_u = {
		.ablkcipher = {
			.min_keysize	= SERPENT_MIN_KEY_SIZE * 2,
			.max_keysize	= SERPENT_MAX_KEY_SIZE * 2,
			.ivsize		= SERPENT_BLOCK_SIZE,
			.setkey		= ablk_set_key,
			.encrypt	= ablk_encrypt,
			.decrypt	= ablk_decrypt,
		},
	},
} };

static int __init serpent_sse2_init(void)
{
	if (!cpu_has_xmm2) {
		printk(KERN_INFO "SSE2 instructions are not detected.\n");
		return -ENODEV;
	}

	return crypto_register_algs(serpent_algs, ARRAY_SIZE(serpent_algs));
}

static void __exit serpent_sse2_exit(void)
{
	crypto_unregister_algs(serpent_algs, ARRAY_SIZE(serpent_algs));
}

module_init(serpent_sse2_init);
module_exit(serpent_sse2_exit);

MODULE_DESCRIPTION("Serpent Cipher Algorithm, SSE2 optimized");
MODULE_LICENSE("GPL");
MODULE_ALIAS("serpent");