xref: /linux/arch/arm/crypto/crc32-ce-core.S (revision d4b996f9ef1fe83d9ce9ad5c1ca0bd8231638ce5) 
1/*
2 * Accelerated CRC32(C) using ARM CRC, NEON and Crypto Extensions instructions
3 *
4 * Copyright (C) 2016 Linaro Ltd <ard.biesheuvel@linaro.org>
5 *
6 * This program is free software; you can redistribute it and/or modify
7 * it under the terms of the GNU General Public License version 2 as
8 * published by the Free Software Foundation.
9 */
10
11/* GPL HEADER START
12 *
13 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
14 *
15 * This program is free software; you can redistribute it and/or modify
16 * it under the terms of the GNU General Public License version 2 only,
17 * as published by the Free Software Foundation.
18 *
19 * This program is distributed in the hope that it will be useful, but
20 * WITHOUT ANY WARRANTY; without even the implied warranty of
21 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
22 * General Public License version 2 for more details (a copy is included
23 * in the LICENSE file that accompanied this code).
24 *
25 * You should have received a copy of the GNU General Public License
26 * version 2 along with this program; If not, see http://www.gnu.org/licenses
27 *
28 * Please  visit http://www.xyratex.com/contact if you need additional
29 * information or have any questions.
30 *
31 * GPL HEADER END
32 */
33
34/*
35 * Copyright 2012 Xyratex Technology Limited
36 *
37 * Using hardware provided PCLMULQDQ instruction to accelerate the CRC32
38 * calculation.
39 * CRC32 polynomial:0x04c11db7(BE)/0xEDB88320(LE)
40 * PCLMULQDQ is a new instruction in Intel SSE4.2, the reference can be found
41 * at:
42 * https://www.intel.com/products/processor/manuals/
43 * Intel(R) 64 and IA-32 Architectures Software Developer's Manual
44 * Volume 2B: Instruction Set Reference, N-Z
45 *
46 * Authors:   Gregory Prestas <Gregory_Prestas@us.xyratex.com>
47 *	      Alexander Boyko <Alexander_Boyko@xyratex.com>
48 */
49
50#include <linux/linkage.h>
51#include <asm/assembler.h>
52
53	.text
54	.align		6
55	.arch		armv8-a
56	.arch_extension	crc
57	.fpu		crypto-neon-fp-armv8
58
59.Lcrc32_constants:
60	/*
61	 * [x4*128+32 mod P(x) << 32)]'  << 1   = 0x154442bd4
62	 * #define CONSTANT_R1  0x154442bd4LL
63	 *
64	 * [(x4*128-32 mod P(x) << 32)]' << 1   = 0x1c6e41596
65	 * #define CONSTANT_R2  0x1c6e41596LL
66	 */
67	.quad		0x0000000154442bd4
68	.quad		0x00000001c6e41596
69
70	/*
71	 * [(x128+32 mod P(x) << 32)]'   << 1   = 0x1751997d0
72	 * #define CONSTANT_R3  0x1751997d0LL
73	 *
74	 * [(x128-32 mod P(x) << 32)]'   << 1   = 0x0ccaa009e
75	 * #define CONSTANT_R4  0x0ccaa009eLL
76	 */
77	.quad		0x00000001751997d0
78	.quad		0x00000000ccaa009e
79
80	/*
81	 * [(x64 mod P(x) << 32)]'       << 1   = 0x163cd6124
82	 * #define CONSTANT_R5  0x163cd6124LL
83	 */
84	.quad		0x0000000163cd6124
85	.quad		0x00000000FFFFFFFF
86
87	/*
88	 * #define CRCPOLY_TRUE_LE_FULL 0x1DB710641LL
89	 *
90	 * Barrett Reduction constant (u64`) = u` = (x**64 / P(x))`
91	 *                                                      = 0x1F7011641LL
92	 * #define CONSTANT_RU  0x1F7011641LL
93	 */
94	.quad		0x00000001DB710641
95	.quad		0x00000001F7011641
96
97.Lcrc32c_constants:
98	.quad		0x00000000740eef02
99	.quad		0x000000009e4addf8
100	.quad		0x00000000f20c0dfe
101	.quad		0x000000014cd00bd6
102	.quad		0x00000000dd45aab8
103	.quad		0x00000000FFFFFFFF
104	.quad		0x0000000105ec76f0
105	.quad		0x00000000dea713f1
106
107	dCONSTANTl	.req	d0
108	dCONSTANTh	.req	d1
109	qCONSTANT	.req	q0
110
111	BUF		.req	r0
112	LEN		.req	r1
113	CRC		.req	r2
114
115	qzr		.req	q9
116
117	/**
118	 * Calculate crc32
119	 * BUF - buffer
120	 * LEN - sizeof buffer (multiple of 16 bytes), LEN should be > 63
121	 * CRC - initial crc32
122	 * return %eax crc32
123	 * uint crc32_pmull_le(unsigned char const *buffer,
124	 *                     size_t len, uint crc32)
125	 */
126ENTRY(crc32_pmull_le)
127	adr		r3, .Lcrc32_constants
128	b		0f
129
130ENTRY(crc32c_pmull_le)
131	adr		r3, .Lcrc32c_constants
132
1330:	bic		LEN, LEN, #15
134	vld1.8		{q1-q2}, [BUF, :128]!
135	vld1.8		{q3-q4}, [BUF, :128]!
136	vmov.i8		qzr, #0
137	vmov.i8		qCONSTANT, #0
138	vmov.32		dCONSTANTl[0], CRC
139	veor.8		d2, d2, dCONSTANTl
140	sub		LEN, LEN, #0x40
141	cmp		LEN, #0x40
142	blt		less_64
143
144	vld1.64		{qCONSTANT}, [r3]
145
146loop_64:		/* 64 bytes Full cache line folding */
147	sub		LEN, LEN, #0x40
148
149	vmull.p64	q5, d3, dCONSTANTh
150	vmull.p64	q6, d5, dCONSTANTh
151	vmull.p64	q7, d7, dCONSTANTh
152	vmull.p64	q8, d9, dCONSTANTh
153
154	vmull.p64	q1, d2, dCONSTANTl
155	vmull.p64	q2, d4, dCONSTANTl
156	vmull.p64	q3, d6, dCONSTANTl
157	vmull.p64	q4, d8, dCONSTANTl
158
159	veor.8		q1, q1, q5
160	vld1.8		{q5}, [BUF, :128]!
161	veor.8		q2, q2, q6
162	vld1.8		{q6}, [BUF, :128]!
163	veor.8		q3, q3, q7
164	vld1.8		{q7}, [BUF, :128]!
165	veor.8		q4, q4, q8
166	vld1.8		{q8}, [BUF, :128]!
167
168	veor.8		q1, q1, q5
169	veor.8		q2, q2, q6
170	veor.8		q3, q3, q7
171	veor.8		q4, q4, q8
172
173	cmp		LEN, #0x40
174	bge		loop_64
175
176less_64:		/* Folding cache line into 128bit */
177	vldr		dCONSTANTl, [r3, #16]
178	vldr		dCONSTANTh, [r3, #24]
179
180	vmull.p64	q5, d3, dCONSTANTh
181	vmull.p64	q1, d2, dCONSTANTl
182	veor.8		q1, q1, q5
183	veor.8		q1, q1, q2
184
185	vmull.p64	q5, d3, dCONSTANTh
186	vmull.p64	q1, d2, dCONSTANTl
187	veor.8		q1, q1, q5
188	veor.8		q1, q1, q3
189
190	vmull.p64	q5, d3, dCONSTANTh
191	vmull.p64	q1, d2, dCONSTANTl
192	veor.8		q1, q1, q5
193	veor.8		q1, q1, q4
194
195	teq		LEN, #0
196	beq		fold_64
197
198loop_16:		/* Folding rest buffer into 128bit */
199	subs		LEN, LEN, #0x10
200
201	vld1.8		{q2}, [BUF, :128]!
202	vmull.p64	q5, d3, dCONSTANTh
203	vmull.p64	q1, d2, dCONSTANTl
204	veor.8		q1, q1, q5
205	veor.8		q1, q1, q2
206
207	bne		loop_16
208
209fold_64:
210	/* perform the last 64 bit fold, also adds 32 zeroes
211	 * to the input stream */
212	vmull.p64	q2, d2, dCONSTANTh
213	vext.8		q1, q1, qzr, #8
214	veor.8		q1, q1, q2
215
216	/* final 32-bit fold */
217	vldr		dCONSTANTl, [r3, #32]
218	vldr		d6, [r3, #40]
219	vmov.i8		d7, #0
220
221	vext.8		q2, q1, qzr, #4
222	vand.8		d2, d2, d6
223	vmull.p64	q1, d2, dCONSTANTl
224	veor.8		q1, q1, q2
225
226	/* Finish up with the bit-reversed barrett reduction 64 ==> 32 bits */
227	vldr		dCONSTANTl, [r3, #48]
228	vldr		dCONSTANTh, [r3, #56]
229
230	vand.8		q2, q1, q3
231	vext.8		q2, qzr, q2, #8
232	vmull.p64	q2, d5, dCONSTANTh
233	vand.8		q2, q2, q3
234	vmull.p64	q2, d4, dCONSTANTl
235	veor.8		q1, q1, q2
236	vmov		r0, s5
237
238	bx		lr
239ENDPROC(crc32_pmull_le)
240ENDPROC(crc32c_pmull_le)
241
242	.macro		__crc32, c
243	subs		ip, r2, #8
244	bmi		.Ltail\c
245
246	tst		r1, #3
247	bne		.Lunaligned\c
248
249	teq		ip, #0
250.Laligned8\c:
251	ldrd		r2, r3, [r1], #8
252ARM_BE8(rev		r2, r2		)
253ARM_BE8(rev		r3, r3		)
254	crc32\c\()w	r0, r0, r2
255	crc32\c\()w	r0, r0, r3
256	bxeq		lr
257	subs		ip, ip, #8
258	bpl		.Laligned8\c
259
260.Ltail\c:
261	tst		ip, #4
262	beq		2f
263	ldr		r3, [r1], #4
264ARM_BE8(rev		r3, r3		)
265	crc32\c\()w	r0, r0, r3
266
2672:	tst		ip, #2
268	beq		1f
269	ldrh		r3, [r1], #2
270ARM_BE8(rev16		r3, r3		)
271	crc32\c\()h	r0, r0, r3
272
2731:	tst		ip, #1
274	bxeq		lr
275	ldrb		r3, [r1]
276	crc32\c\()b	r0, r0, r3
277	bx		lr
278
279.Lunaligned\c:
280	tst		r1, #1
281	beq		2f
282	ldrb		r3, [r1], #1
283	subs		r2, r2, #1
284	crc32\c\()b	r0, r0, r3
285
286	tst		r1, #2
287	beq		0f
2882:	ldrh		r3, [r1], #2
289	subs		r2, r2, #2
290ARM_BE8(rev16		r3, r3		)
291	crc32\c\()h	r0, r0, r3
292
2930:	subs		ip, r2, #8
294	bpl		.Laligned8\c
295	b		.Ltail\c
296	.endm
297
298	.align		5
299ENTRY(crc32_armv8_le)
300	__crc32
301ENDPROC(crc32_armv8_le)
302
303	.align		5
304ENTRY(crc32c_armv8_le)
305	__crc32		c
306ENDPROC(crc32c_armv8_le)
307