summaryrefslogtreecommitdiff
path: root/arch/arm64/crypto/aes-modes.S
blob: 131618389f1fda7fd3744ce0584a33ce5cc20388 (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
/* SPDX-License-Identifier: GPL-2.0-only */
/*
 * linux/arch/arm64/crypto/aes-modes.S - chaining mode wrappers for AES
 *
 * Copyright (C) 2013 - 2017 Linaro Ltd <ard.biesheuvel@linaro.org>
 */

/* included by aes-ce.S and aes-neon.S */

	.text
	.align		4

#ifndef MAX_STRIDE
#define MAX_STRIDE	4
#endif

#if MAX_STRIDE == 4
#define ST4(x...) x
#define ST5(x...)
#else
#define ST4(x...)
#define ST5(x...) x
#endif

aes_encrypt_block4x:
	encrypt_block4x	v0, v1, v2, v3, w3, x2, x8, w7
	ret
ENDPROC(aes_encrypt_block4x)

aes_decrypt_block4x:
	decrypt_block4x	v0, v1, v2, v3, w3, x2, x8, w7
	ret
ENDPROC(aes_decrypt_block4x)

#if MAX_STRIDE == 5
aes_encrypt_block5x:
	encrypt_block5x	v0, v1, v2, v3, v4, w3, x2, x8, w7
	ret
ENDPROC(aes_encrypt_block5x)

aes_decrypt_block5x:
	decrypt_block5x	v0, v1, v2, v3, v4, w3, x2, x8, w7
	ret
ENDPROC(aes_decrypt_block5x)
#endif

	/*
	 * aes_ecb_encrypt(u8 out[], u8 const in[], u8 const rk[], int rounds,
	 *		   int blocks)
	 * aes_ecb_decrypt(u8 out[], u8 const in[], u8 const rk[], int rounds,
	 *		   int blocks)
	 */

AES_ENTRY(aes_ecb_encrypt)
	stp		x29, x30, [sp, #-16]!
	mov		x29, sp

	enc_prepare	w3, x2, x5

.LecbencloopNx:
	subs		w4, w4, #MAX_STRIDE
	bmi		.Lecbenc1x
	ld1		{v0.16b-v3.16b}, [x1], #64	/* get 4 pt blocks */
ST4(	bl		aes_encrypt_block4x		)
ST5(	ld1		{v4.16b}, [x1], #16		)
ST5(	bl		aes_encrypt_block5x		)
	st1		{v0.16b-v3.16b}, [x0], #64
ST5(	st1		{v4.16b}, [x0], #16		)
	b		.LecbencloopNx
.Lecbenc1x:
	adds		w4, w4, #MAX_STRIDE
	beq		.Lecbencout
.Lecbencloop:
	ld1		{v0.16b}, [x1], #16		/* get next pt block */
	encrypt_block	v0, w3, x2, x5, w6
	st1		{v0.16b}, [x0], #16
	subs		w4, w4, #1
	bne		.Lecbencloop
.Lecbencout:
	ldp		x29, x30, [sp], #16
	ret
AES_ENDPROC(aes_ecb_encrypt)


AES_ENTRY(aes_ecb_decrypt)
	stp		x29, x30, [sp, #-16]!
	mov		x29, sp

	dec_prepare	w3, x2, x5

.LecbdecloopNx:
	subs		w4, w4, #MAX_STRIDE
	bmi		.Lecbdec1x
	ld1		{v0.16b-v3.16b}, [x1], #64	/* get 4 ct blocks */
ST4(	bl		aes_decrypt_block4x		)
ST5(	ld1		{v4.16b}, [x1], #16		)
ST5(	bl		aes_decrypt_block5x		)
	st1		{v0.16b-v3.16b}, [x0], #64
ST5(	st1		{v4.16b}, [x0], #16		)
	b		.LecbdecloopNx
.Lecbdec1x:
	adds		w4, w4, #MAX_STRIDE
	beq		.Lecbdecout
.Lecbdecloop:
	ld1		{v0.16b}, [x1], #16		/* get next ct block */
	decrypt_block	v0, w3, x2, x5, w6
	st1		{v0.16b}, [x0], #16
	subs		w4, w4, #1
	bne		.Lecbdecloop
.Lecbdecout:
	ldp		x29, x30, [sp], #16
	ret
AES_ENDPROC(aes_ecb_decrypt)


	/*
	 * aes_cbc_encrypt(u8 out[], u8 const in[], u8 const rk[], int rounds,
	 *		   int blocks, u8 iv[])
	 * aes_cbc_decrypt(u8 out[], u8 const in[], u8 const rk[], int rounds,
	 *		   int blocks, u8 iv[])
	 * aes_essiv_cbc_encrypt(u8 out[], u8 const in[], u32 const rk1[],
	 *			 int rounds, int blocks, u8 iv[],
	 *			 u32 const rk2[]);
	 * aes_essiv_cbc_decrypt(u8 out[], u8 const in[], u32 const rk1[],
	 *			 int rounds, int blocks, u8 iv[],
	 *			 u32 const rk2[]);
	 */

AES_ENTRY(aes_essiv_cbc_encrypt)
	ld1		{v4.16b}, [x5]			/* get iv */

	mov		w8, #14				/* AES-256: 14 rounds */
	enc_prepare	w8, x6, x7
	encrypt_block	v4, w8, x6, x7, w9
	enc_switch_key	w3, x2, x6
	b		.Lcbcencloop4x

AES_ENTRY(aes_cbc_encrypt)
	ld1		{v4.16b}, [x5]			/* get iv */
	enc_prepare	w3, x2, x6

.Lcbcencloop4x:
	subs		w4, w4, #4
	bmi		.Lcbcenc1x
	ld1		{v0.16b-v3.16b}, [x1], #64	/* get 4 pt blocks */
	eor		v0.16b, v0.16b, v4.16b		/* ..and xor with iv */
	encrypt_block	v0, w3, x2, x6, w7
	eor		v1.16b, v1.16b, v0.16b
	encrypt_block	v1, w3, x2, x6, w7
	eor		v2.16b, v2.16b, v1.16b
	encrypt_block	v2, w3, x2, x6, w7
	eor		v3.16b, v3.16b, v2.16b
	encrypt_block	v3, w3, x2, x6, w7
	st1		{v0.16b-v3.16b}, [x0], #64
	mov		v4.16b, v3.16b
	b		.Lcbcencloop4x
.Lcbcenc1x:
	adds		w4, w4, #4
	beq		.Lcbcencout
.Lcbcencloop:
	ld1		{v0.16b}, [x1], #16		/* get next pt block */
	eor		v4.16b, v4.16b, v0.16b		/* ..and xor with iv */
	encrypt_block	v4, w3, x2, x6, w7
	st1		{v4.16b}, [x0], #16
	subs		w4, w4, #1
	bne		.Lcbcencloop
.Lcbcencout:
	st1		{v4.16b}, [x5]			/* return iv */
	ret
AES_ENDPROC(aes_cbc_encrypt)
AES_ENDPROC(aes_essiv_cbc_encrypt)

AES_ENTRY(aes_essiv_cbc_decrypt)
	stp		x29, x30, [sp, #-16]!
	mov		x29, sp

	ld1		{cbciv.16b}, [x5]		/* get iv */

	mov		w8, #14				/* AES-256: 14 rounds */
	enc_prepare	w8, x6, x7
	encrypt_block	cbciv, w8, x6, x7, w9
	b		.Lessivcbcdecstart

AES_ENTRY(aes_cbc_decrypt)
	stp		x29, x30, [sp, #-16]!
	mov		x29, sp

	ld1		{cbciv.16b}, [x5]		/* get iv */
.Lessivcbcdecstart:
	dec_prepare	w3, x2, x6

.LcbcdecloopNx:
	subs		w4, w4, #MAX_STRIDE
	bmi		.Lcbcdec1x
	ld1		{v0.16b-v3.16b}, [x1], #64	/* get 4 ct blocks */
#if MAX_STRIDE == 5
	ld1		{v4.16b}, [x1], #16		/* get 1 ct block */
	mov		v5.16b, v0.16b
	mov		v6.16b, v1.16b
	mov		v7.16b, v2.16b
	bl		aes_decrypt_block5x
	sub		x1, x1, #32
	eor		v0.16b, v0.16b, cbciv.16b
	eor		v1.16b, v1.16b, v5.16b
	ld1		{v5.16b}, [x1], #16		/* reload 1 ct block */
	ld1		{cbciv.16b}, [x1], #16		/* reload 1 ct block */
	eor		v2.16b, v2.16b, v6.16b
	eor		v3.16b, v3.16b, v7.16b
	eor		v4.16b, v4.16b, v5.16b
#else
	mov		v4.16b, v0.16b
	mov		v5.16b, v1.16b
	mov		v6.16b, v2.16b
	bl		aes_decrypt_block4x
	sub		x1, x1, #16
	eor		v0.16b, v0.16b, cbciv.16b
	eor		v1.16b, v1.16b, v4.16b
	ld1		{cbciv.16b}, [x1], #16		/* reload 1 ct block */
	eor		v2.16b, v2.16b, v5.16b
	eor		v3.16b, v3.16b, v6.16b
#endif
	st1		{v0.16b-v3.16b}, [x0], #64
ST5(	st1		{v4.16b}, [x0], #16		)
	b		.LcbcdecloopNx
.Lcbcdec1x:
	adds		w4, w4, #MAX_STRIDE
	beq		.Lcbcdecout
.Lcbcdecloop:
	ld1		{v1.16b}, [x1], #16		/* get next ct block */
	mov		v0.16b, v1.16b			/* ...and copy to v0 */
	decrypt_block	v0, w3, x2, x6, w7
	eor		v0.16b, v0.16b, cbciv.16b	/* xor with iv => pt */
	mov		cbciv.16b, v1.16b		/* ct is next iv */
	st1		{v0.16b}, [x0], #16
	subs		w4, w4, #1
	bne		.Lcbcdecloop
.Lcbcdecout:
	st1		{cbciv.16b}, [x5]		/* return iv */
	ldp		x29, x30, [sp], #16
	ret
AES_ENDPROC(aes_cbc_decrypt)
AES_ENDPROC(aes_essiv_cbc_decrypt)


	/*
	 * aes_cbc_cts_encrypt(u8 out[], u8 const in[], u32 const rk[],
	 *		       int rounds, int bytes, u8 const iv[])
	 * aes_cbc_cts_decrypt(u8 out[], u8 const in[], u32 const rk[],
	 *		       int rounds, int bytes, u8 const iv[])
	 */

AES_ENTRY(aes_cbc_cts_encrypt)
	adr_l		x8, .Lcts_permute_table
	sub		x4, x4, #16
	add		x9, x8, #32
	add		x8, x8, x4
	sub		x9, x9, x4
	ld1		{v3.16b}, [x8]
	ld1		{v4.16b}, [x9]

	ld1		{v0.16b}, [x1], x4		/* overlapping loads */
	ld1		{v1.16b}, [x1]

	ld1		{v5.16b}, [x5]			/* get iv */
	enc_prepare	w3, x2, x6

	eor		v0.16b, v0.16b, v5.16b		/* xor with iv */
	tbl		v1.16b, {v1.16b}, v4.16b
	encrypt_block	v0, w3, x2, x6, w7

	eor		v1.16b, v1.16b, v0.16b
	tbl		v0.16b, {v0.16b}, v3.16b
	encrypt_block	v1, w3, x2, x6, w7

	add		x4, x0, x4
	st1		{v0.16b}, [x4]			/* overlapping stores */
	st1		{v1.16b}, [x0]
	ret
AES_ENDPROC(aes_cbc_cts_encrypt)

AES_ENTRY(aes_cbc_cts_decrypt)
	adr_l		x8, .Lcts_permute_table
	sub		x4, x4, #16
	add		x9, x8, #32
	add		x8, x8, x4
	sub		x9, x9, x4
	ld1		{v3.16b}, [x8]
	ld1		{v4.16b}, [x9]

	ld1		{v0.16b}, [x1], x4		/* overlapping loads */
	ld1		{v1.16b}, [x1]

	ld1		{v5.16b}, [x5]			/* get iv */
	dec_prepare	w3, x2, x6

	decrypt_block	v0, w3, x2, x6, w7
	tbl		v2.16b, {v0.16b}, v3.16b
	eor		v2.16b, v2.16b, v1.16b

	tbx		v0.16b, {v1.16b}, v4.16b
	decrypt_block	v0, w3, x2, x6, w7
	eor		v0.16b, v0.16b, v5.16b		/* xor with iv */

	add		x4, x0, x4
	st1		{v2.16b}, [x4]			/* overlapping stores */
	st1		{v0.16b}, [x0]
	ret
AES_ENDPROC(aes_cbc_cts_decrypt)

	.section	".rodata", "a"
	.align		6
.Lcts_permute_table:
	.byte		0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff
	.byte		0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff
	.byte		 0x0,  0x1,  0x2,  0x3,  0x4,  0x5,  0x6,  0x7
	.byte		 0x8,  0x9,  0xa,  0xb,  0xc,  0xd,  0xe,  0xf
	.byte		0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff
	.byte		0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff
	.previous


	/*
	 * aes_ctr_encrypt(u8 out[], u8 const in[], u8 const rk[], int rounds,
	 *		   int blocks, u8 ctr[])
	 */

AES_ENTRY(aes_ctr_encrypt)
	stp		x29, x30, [sp, #-16]!
	mov		x29, sp

	enc_prepare	w3, x2, x6
	ld1		{vctr.16b}, [x5]

	umov		x6, vctr.d[1]		/* keep swabbed ctr in reg */
	rev		x6, x6
	cmn		w6, w4			/* 32 bit overflow? */
	bcs		.Lctrloop
.LctrloopNx:
	subs		w4, w4, #MAX_STRIDE
	bmi		.Lctr1x
	add		w7, w6, #1
	mov		v0.16b, vctr.16b
	add		w8, w6, #2
	mov		v1.16b, vctr.16b
	add		w9, w6, #3
	mov		v2.16b, vctr.16b
	add		w9, w6, #3
	rev		w7, w7
	mov		v3.16b, vctr.16b
	rev		w8, w8
ST5(	mov		v4.16b, vctr.16b		)
	mov		v1.s[3], w7
	rev		w9, w9
ST5(	add		w10, w6, #4			)
	mov		v2.s[3], w8
ST5(	rev		w10, w10			)
	mov		v3.s[3], w9
ST5(	mov		v4.s[3], w10			)
	ld1		{v5.16b-v7.16b}, [x1], #48	/* get 3 input blocks */
ST4(	bl		aes_encrypt_block4x		)
ST5(	bl		aes_encrypt_block5x		)
	eor		v0.16b, v5.16b, v0.16b
ST4(	ld1		{v5.16b}, [x1], #16		)
	eor		v1.16b, v6.16b, v1.16b
ST5(	ld1		{v5.16b-v6.16b}, [x1], #32	)
	eor		v2.16b, v7.16b, v2.16b
	eor		v3.16b, v5.16b, v3.16b
ST5(	eor		v4.16b, v6.16b, v4.16b		)
	st1		{v0.16b-v3.16b}, [x0], #64
ST5(	st1		{v4.16b}, [x0], #16		)
	add		x6, x6, #MAX_STRIDE
	rev		x7, x6
	ins		vctr.d[1], x7
	cbz		w4, .Lctrout
	b		.LctrloopNx
.Lctr1x:
	adds		w4, w4, #MAX_STRIDE
	beq		.Lctrout
.Lctrloop:
	mov		v0.16b, vctr.16b
	encrypt_block	v0, w3, x2, x8, w7

	adds		x6, x6, #1		/* increment BE ctr */
	rev		x7, x6
	ins		vctr.d[1], x7
	bcs		.Lctrcarry		/* overflow? */

.Lctrcarrydone:
	subs		w4, w4, #1
	bmi		.Lctrtailblock		/* blocks <0 means tail block */
	ld1		{v3.16b}, [x1], #16
	eor		v3.16b, v0.16b, v3.16b
	st1		{v3.16b}, [x0], #16
	bne		.Lctrloop

.Lctrout:
	st1		{vctr.16b}, [x5]	/* return next CTR value */
	ldp		x29, x30, [sp], #16
	ret

.Lctrtailblock:
	st1		{v0.16b}, [x0]
	b		.Lctrout

.Lctrcarry:
	umov		x7, vctr.d[0]		/* load upper word of ctr  */
	rev		x7, x7			/* ... to handle the carry */
	add		x7, x7, #1
	rev		x7, x7
	ins		vctr.d[0], x7
	b		.Lctrcarrydone
AES_ENDPROC(aes_ctr_encrypt)


	/*
	 * aes_xts_encrypt(u8 out[], u8 const in[], u8 const rk1[], int rounds,
	 *		   int bytes, u8 const rk2[], u8 iv[], int first)
	 * aes_xts_decrypt(u8 out[], u8 const in[], u8 const rk1[], int rounds,
	 *		   int bytes, u8 const rk2[], u8 iv[], int first)
	 */

	.macro		next_tweak, out, in, tmp
	sshr		\tmp\().2d,  \in\().2d,   #63
	and		\tmp\().16b, \tmp\().16b, xtsmask.16b
	add		\out\().2d,  \in\().2d,   \in\().2d
	ext		\tmp\().16b, \tmp\().16b, \tmp\().16b, #8
	eor		\out\().16b, \out\().16b, \tmp\().16b
	.endm

	.macro		xts_load_mask, tmp
	movi		xtsmask.2s, #0x1
	movi		\tmp\().2s, #0x87
	uzp1		xtsmask.4s, xtsmask.4s, \tmp\().4s
	.endm

AES_ENTRY(aes_xts_encrypt)
	stp		x29, x30, [sp, #-16]!
	mov		x29, sp

	ld1		{v4.16b}, [x6]
	xts_load_mask	v8
	cbz		w7, .Lxtsencnotfirst

	enc_prepare	w3, x5, x8
	xts_cts_skip_tw	w7, .LxtsencNx
	encrypt_block	v4, w3, x5, x8, w7		/* first tweak */
	enc_switch_key	w3, x2, x8
	b		.LxtsencNx

.Lxtsencnotfirst:
	enc_prepare	w3, x2, x8
.LxtsencloopNx:
	next_tweak	v4, v4, v8
.LxtsencNx:
	subs		w4, w4, #64
	bmi		.Lxtsenc1x
	ld1		{v0.16b-v3.16b}, [x1], #64	/* get 4 pt blocks */
	next_tweak	v5, v4, v8
	eor		v0.16b, v0.16b, v4.16b
	next_tweak	v6, v5, v8
	eor		v1.16b, v1.16b, v5.16b
	eor		v2.16b, v2.16b, v6.16b
	next_tweak	v7, v6, v8
	eor		v3.16b, v3.16b, v7.16b
	bl		aes_encrypt_block4x
	eor		v3.16b, v3.16b, v7.16b
	eor		v0.16b, v0.16b, v4.16b
	eor		v1.16b, v1.16b, v5.16b
	eor		v2.16b, v2.16b, v6.16b
	st1		{v0.16b-v3.16b}, [x0], #64
	mov		v4.16b, v7.16b
	cbz		w4, .Lxtsencret
	xts_reload_mask	v8
	b		.LxtsencloopNx
.Lxtsenc1x:
	adds		w4, w4, #64
	beq		.Lxtsencout
	subs		w4, w4, #16
	bmi		.LxtsencctsNx
.Lxtsencloop:
	ld1		{v0.16b}, [x1], #16
.Lxtsencctsout:
	eor		v0.16b, v0.16b, v4.16b
	encrypt_block	v0, w3, x2, x8, w7
	eor		v0.16b, v0.16b, v4.16b
	cbz		w4, .Lxtsencout
	subs		w4, w4, #16
	next_tweak	v4, v4, v8
	bmi		.Lxtsenccts
	st1		{v0.16b}, [x0], #16
	b		.Lxtsencloop
.Lxtsencout:
	st1		{v0.16b}, [x0]
.Lxtsencret:
	st1		{v4.16b}, [x6]
	ldp		x29, x30, [sp], #16
	ret

.LxtsencctsNx:
	mov		v0.16b, v3.16b
	sub		x0, x0, #16
.Lxtsenccts:
	adr_l		x8, .Lcts_permute_table

	add		x1, x1, w4, sxtw	/* rewind input pointer */
	add		w4, w4, #16		/* # bytes in final block */
	add		x9, x8, #32
	add		x8, x8, x4
	sub		x9, x9, x4
	add		x4, x0, x4		/* output address of final block */

	ld1		{v1.16b}, [x1]		/* load final block */
	ld1		{v2.16b}, [x8]
	ld1		{v3.16b}, [x9]

	tbl		v2.16b, {v0.16b}, v2.16b
	tbx		v0.16b, {v1.16b}, v3.16b
	st1		{v2.16b}, [x4]			/* overlapping stores */
	mov		w4, wzr
	b		.Lxtsencctsout
AES_ENDPROC(aes_xts_encrypt)

AES_ENTRY(aes_xts_decrypt)
	stp		x29, x30, [sp, #-16]!
	mov		x29, sp

	/* subtract 16 bytes if we are doing CTS */
	sub		w8, w4, #0x10
	tst		w4, #0xf
	csel		w4, w4, w8, eq

	ld1		{v4.16b}, [x6]
	xts_load_mask	v8
	xts_cts_skip_tw	w7, .Lxtsdecskiptw
	cbz		w7, .Lxtsdecnotfirst

	enc_prepare	w3, x5, x8
	encrypt_block	v4, w3, x5, x8, w7		/* first tweak */
.Lxtsdecskiptw:
	dec_prepare	w3, x2, x8
	b		.LxtsdecNx

.Lxtsdecnotfirst:
	dec_prepare	w3, x2, x8
.LxtsdecloopNx:
	next_tweak	v4, v4, v8
.LxtsdecNx:
	subs		w4, w4, #64
	bmi		.Lxtsdec1x
	ld1		{v0.16b-v3.16b}, [x1], #64	/* get 4 ct blocks */
	next_tweak	v5, v4, v8
	eor		v0.16b, v0.16b, v4.16b
	next_tweak	v6, v5, v8
	eor		v1.16b, v1.16b, v5.16b
	eor		v2.16b, v2.16b, v6.16b
	next_tweak	v7, v6, v8
	eor		v3.16b, v3.16b, v7.16b
	bl		aes_decrypt_block4x
	eor		v3.16b, v3.16b, v7.16b
	eor		v0.16b, v0.16b, v4.16b
	eor		v1.16b, v1.16b, v5.16b
	eor		v2.16b, v2.16b, v6.16b
	st1		{v0.16b-v3.16b}, [x0], #64
	mov		v4.16b, v7.16b
	cbz		w4, .Lxtsdecout
	xts_reload_mask	v8
	b		.LxtsdecloopNx
.Lxtsdec1x:
	adds		w4, w4, #64
	beq		.Lxtsdecout
	subs		w4, w4, #16
.Lxtsdecloop:
	ld1		{v0.16b}, [x1], #16
	bmi		.Lxtsdeccts
.Lxtsdecctsout:
	eor		v0.16b, v0.16b, v4.16b
	decrypt_block	v0, w3, x2, x8, w7
	eor		v0.16b, v0.16b, v4.16b
	st1		{v0.16b}, [x0], #16
	cbz		w4, .Lxtsdecout
	subs		w4, w4, #16
	next_tweak	v4, v4, v8
	b		.Lxtsdecloop
.Lxtsdecout:
	st1		{v4.16b}, [x6]
	ldp		x29, x30, [sp], #16
	ret

.Lxtsdeccts:
	adr_l		x8, .Lcts_permute_table

	add		x1, x1, w4, sxtw	/* rewind input pointer */
	add		w4, w4, #16		/* # bytes in final block */
	add		x9, x8, #32
	add		x8, x8, x4
	sub		x9, x9, x4
	add		x4, x0, x4		/* output address of final block */

	next_tweak	v5, v4, v8

	ld1		{v1.16b}, [x1]		/* load final block */
	ld1		{v2.16b}, [x8]
	ld1		{v3.16b}, [x9]

	eor		v0.16b, v0.16b, v5.16b
	decrypt_block	v0, w3, x2, x8, w7
	eor		v0.16b, v0.16b, v5.16b

	tbl		v2.16b, {v0.16b}, v2.16b
	tbx		v0.16b, {v1.16b}, v3.16b

	st1		{v2.16b}, [x4]			/* overlapping stores */
	mov		w4, wzr
	b		.Lxtsdecctsout
AES_ENDPROC(aes_xts_decrypt)

	/*
	 * aes_mac_update(u8 const in[], u32 const rk[], int rounds,
	 *		  int blocks, u8 dg[], int enc_before, int enc_after)
	 */
AES_ENTRY(aes_mac_update)
	frame_push	6

	mov		x19, x0
	mov		x20, x1
	mov		x21, x2
	mov		x22, x3
	mov		x23, x4
	mov		x24, x6

	ld1		{v0.16b}, [x23]			/* get dg */
	enc_prepare	w2, x1, x7
	cbz		w5, .Lmacloop4x

	encrypt_block	v0, w2, x1, x7, w8

.Lmacloop4x:
	subs		w22, w22, #4
	bmi		.Lmac1x
	ld1		{v1.16b-v4.16b}, [x19], #64	/* get next pt block */
	eor		v0.16b, v0.16b, v1.16b		/* ..and xor with dg */
	encrypt_block	v0, w21, x20, x7, w8
	eor		v0.16b, v0.16b, v2.16b
	encrypt_block	v0, w21, x20, x7, w8
	eor		v0.16b, v0.16b, v3.16b
	encrypt_block	v0, w21, x20, x7, w8
	eor		v0.16b, v0.16b, v4.16b
	cmp		w22, wzr
	csinv		x5, x24, xzr, eq
	cbz		w5, .Lmacout
	encrypt_block	v0, w21, x20, x7, w8
	st1		{v0.16b}, [x23]			/* return dg */
	cond_yield_neon	.Lmacrestart
	b		.Lmacloop4x
.Lmac1x:
	add		w22, w22, #4
.Lmacloop:
	cbz		w22, .Lmacout
	ld1		{v1.16b}, [x19], #16		/* get next pt block */
	eor		v0.16b, v0.16b, v1.16b		/* ..and xor with dg */

	subs		w22, w22, #1
	csinv		x5, x24, xzr, eq
	cbz		w5, .Lmacout

.Lmacenc:
	encrypt_block	v0, w21, x20, x7, w8
	b		.Lmacloop

.Lmacout:
	st1		{v0.16b}, [x23]			/* return dg */
	frame_pop
	ret

.Lmacrestart:
	ld1		{v0.16b}, [x23]			/* get dg */
	enc_prepare	w21, x20, x0
	b		.Lmacloop4x
AES_ENDPROC(aes_mac_update)