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 * http://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 */
126 ENTRY(crc32_pmull_le)
127 adr r3, .Lcrc32_constants
128 b 0f
129
130 ENTRY(crc32c_pmull_le)
131 adr r3, .Lcrc32c_constants
132
133 0: 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
146 loop_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
176 less_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
198 loop_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
209 fold_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
239 ENDPROC(crc32_pmull_le)
240 ENDPROC(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
252 ARM_BE8(rev r2, r2 )
253 ARM_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
264 ARM_BE8(rev r3, r3 )
265 crc32\c\()w r0, r0, r3
266
267 2: tst ip, #2
268 beq 1f
269 ldrh r3, [r1], #2
270 ARM_BE8(rev16 r3, r3 )
271 crc32\c\()h r0, r0, r3
272
273 1: 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
288 2: ldrh r3, [r1], #2
289 subs r2, r2, #2
290 ARM_BE8(rev16 r3, r3 )
291 crc32\c\()h r0, r0, r3
292
293 0: subs ip, r2, #8
294 bpl .Laligned8\c
295 b .Ltail\c
296 .endm
297
298 .align 5
299 ENTRY(crc32_armv8_le)
300 __crc32
301 ENDPROC(crc32_armv8_le)
302
303 .align 5
304 ENTRY(crc32c_armv8_le)
305 __crc32 c
306 ENDPROC(crc32c_armv8_le)