Ard Biesheuvel | dc6ff202 | 2016-12-08 14:28:59 +0000 | [diff] [blame] | 1 | /* |
| 2 | * ChaCha20 256-bit cipher algorithm, RFC7539, ARM NEON functions |
| 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 | * Based on: |
| 11 | * ChaCha20 256-bit cipher algorithm, RFC7539, x64 SSE3 functions |
| 12 | * |
| 13 | * Copyright (C) 2015 Martin Willi |
| 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 as published by |
| 17 | * the Free Software Foundation; either version 2 of the License, or |
| 18 | * (at your option) any later version. |
| 19 | */ |
| 20 | |
Eric Biggers | d233322 | 2018-09-01 00:17:07 -0700 | [diff] [blame^] | 21 | /* |
| 22 | * NEON doesn't have a rotate instruction. The alternatives are, more or less: |
| 23 | * |
| 24 | * (a) vshl.u32 + vsri.u32 (needs temporary register) |
| 25 | * (b) vshl.u32 + vshr.u32 + vorr (needs temporary register) |
| 26 | * (c) vrev32.16 (16-bit rotations only) |
| 27 | * (d) vtbl.8 + vtbl.8 (multiple of 8 bits rotations only, |
| 28 | * needs index vector) |
| 29 | * |
| 30 | * ChaCha20 has 16, 12, 8, and 7-bit rotations. For the 12 and 7-bit |
| 31 | * rotations, the only choices are (a) and (b). We use (a) since it takes |
| 32 | * two-thirds the cycles of (b) on both Cortex-A7 and Cortex-A53. |
| 33 | * |
| 34 | * For the 16-bit rotation, we use vrev32.16 since it's consistently fastest |
| 35 | * and doesn't need a temporary register. |
| 36 | * |
| 37 | * For the 8-bit rotation, we use vtbl.8 + vtbl.8. On Cortex-A7, this sequence |
| 38 | * is twice as fast as (a), even when doing (a) on multiple registers |
| 39 | * simultaneously to eliminate the stall between vshl and vsri. Also, it |
| 40 | * parallelizes better when temporary registers are scarce. |
| 41 | * |
| 42 | * A disadvantage is that on Cortex-A53, the vtbl sequence is the same speed as |
| 43 | * (a), so the need to load the rotation table actually makes the vtbl method |
| 44 | * slightly slower overall on that CPU (~1.3% slower ChaCha20). Still, it |
| 45 | * seems to be a good compromise to get a more significant speed boost on some |
| 46 | * CPUs, e.g. ~4.8% faster ChaCha20 on Cortex-A7. |
| 47 | */ |
| 48 | |
Ard Biesheuvel | dc6ff202 | 2016-12-08 14:28:59 +0000 | [diff] [blame] | 49 | #include <linux/linkage.h> |
| 50 | |
| 51 | .text |
| 52 | .fpu neon |
| 53 | .align 5 |
| 54 | |
| 55 | ENTRY(chacha20_block_xor_neon) |
| 56 | // r0: Input state matrix, s |
| 57 | // r1: 1 data block output, o |
| 58 | // r2: 1 data block input, i |
| 59 | |
| 60 | // |
| 61 | // This function encrypts one ChaCha20 block by loading the state matrix |
| 62 | // in four NEON registers. It performs matrix operation on four words in |
| 63 | // parallel, but requireds shuffling to rearrange the words after each |
| 64 | // round. |
| 65 | // |
| 66 | |
| 67 | // x0..3 = s0..3 |
| 68 | add ip, r0, #0x20 |
| 69 | vld1.32 {q0-q1}, [r0] |
| 70 | vld1.32 {q2-q3}, [ip] |
| 71 | |
| 72 | vmov q8, q0 |
| 73 | vmov q9, q1 |
| 74 | vmov q10, q2 |
| 75 | vmov q11, q3 |
| 76 | |
Eric Biggers | d233322 | 2018-09-01 00:17:07 -0700 | [diff] [blame^] | 77 | adr ip, .Lrol8_table |
Ard Biesheuvel | dc6ff202 | 2016-12-08 14:28:59 +0000 | [diff] [blame] | 78 | mov r3, #10 |
Eric Biggers | d233322 | 2018-09-01 00:17:07 -0700 | [diff] [blame^] | 79 | vld1.8 {d10}, [ip, :64] |
Ard Biesheuvel | dc6ff202 | 2016-12-08 14:28:59 +0000 | [diff] [blame] | 80 | |
| 81 | .Ldoubleround: |
| 82 | // x0 += x1, x3 = rotl32(x3 ^ x0, 16) |
| 83 | vadd.i32 q0, q0, q1 |
Eric Biggers | 52e5ce3 | 2018-07-24 18:29:07 -0700 | [diff] [blame] | 84 | veor q3, q3, q0 |
| 85 | vrev32.16 q3, q3 |
Ard Biesheuvel | dc6ff202 | 2016-12-08 14:28:59 +0000 | [diff] [blame] | 86 | |
| 87 | // x2 += x3, x1 = rotl32(x1 ^ x2, 12) |
| 88 | vadd.i32 q2, q2, q3 |
| 89 | veor q4, q1, q2 |
| 90 | vshl.u32 q1, q4, #12 |
| 91 | vsri.u32 q1, q4, #20 |
| 92 | |
| 93 | // x0 += x1, x3 = rotl32(x3 ^ x0, 8) |
| 94 | vadd.i32 q0, q0, q1 |
Eric Biggers | d233322 | 2018-09-01 00:17:07 -0700 | [diff] [blame^] | 95 | veor q3, q3, q0 |
| 96 | vtbl.8 d6, {d6}, d10 |
| 97 | vtbl.8 d7, {d7}, d10 |
Ard Biesheuvel | dc6ff202 | 2016-12-08 14:28:59 +0000 | [diff] [blame] | 98 | |
| 99 | // x2 += x3, x1 = rotl32(x1 ^ x2, 7) |
| 100 | vadd.i32 q2, q2, q3 |
| 101 | veor q4, q1, q2 |
| 102 | vshl.u32 q1, q4, #7 |
| 103 | vsri.u32 q1, q4, #25 |
| 104 | |
| 105 | // x1 = shuffle32(x1, MASK(0, 3, 2, 1)) |
| 106 | vext.8 q1, q1, q1, #4 |
| 107 | // x2 = shuffle32(x2, MASK(1, 0, 3, 2)) |
| 108 | vext.8 q2, q2, q2, #8 |
| 109 | // x3 = shuffle32(x3, MASK(2, 1, 0, 3)) |
| 110 | vext.8 q3, q3, q3, #12 |
| 111 | |
| 112 | // x0 += x1, x3 = rotl32(x3 ^ x0, 16) |
| 113 | vadd.i32 q0, q0, q1 |
Eric Biggers | 52e5ce3 | 2018-07-24 18:29:07 -0700 | [diff] [blame] | 114 | veor q3, q3, q0 |
| 115 | vrev32.16 q3, q3 |
Ard Biesheuvel | dc6ff202 | 2016-12-08 14:28:59 +0000 | [diff] [blame] | 116 | |
| 117 | // x2 += x3, x1 = rotl32(x1 ^ x2, 12) |
| 118 | vadd.i32 q2, q2, q3 |
| 119 | veor q4, q1, q2 |
| 120 | vshl.u32 q1, q4, #12 |
| 121 | vsri.u32 q1, q4, #20 |
| 122 | |
| 123 | // x0 += x1, x3 = rotl32(x3 ^ x0, 8) |
| 124 | vadd.i32 q0, q0, q1 |
Eric Biggers | d233322 | 2018-09-01 00:17:07 -0700 | [diff] [blame^] | 125 | veor q3, q3, q0 |
| 126 | vtbl.8 d6, {d6}, d10 |
| 127 | vtbl.8 d7, {d7}, d10 |
Ard Biesheuvel | dc6ff202 | 2016-12-08 14:28:59 +0000 | [diff] [blame] | 128 | |
| 129 | // x2 += x3, x1 = rotl32(x1 ^ x2, 7) |
| 130 | vadd.i32 q2, q2, q3 |
| 131 | veor q4, q1, q2 |
| 132 | vshl.u32 q1, q4, #7 |
| 133 | vsri.u32 q1, q4, #25 |
| 134 | |
| 135 | // x1 = shuffle32(x1, MASK(2, 1, 0, 3)) |
| 136 | vext.8 q1, q1, q1, #12 |
| 137 | // x2 = shuffle32(x2, MASK(1, 0, 3, 2)) |
| 138 | vext.8 q2, q2, q2, #8 |
| 139 | // x3 = shuffle32(x3, MASK(0, 3, 2, 1)) |
| 140 | vext.8 q3, q3, q3, #4 |
| 141 | |
| 142 | subs r3, r3, #1 |
| 143 | bne .Ldoubleround |
| 144 | |
| 145 | add ip, r2, #0x20 |
| 146 | vld1.8 {q4-q5}, [r2] |
| 147 | vld1.8 {q6-q7}, [ip] |
| 148 | |
| 149 | // o0 = i0 ^ (x0 + s0) |
| 150 | vadd.i32 q0, q0, q8 |
| 151 | veor q0, q0, q4 |
| 152 | |
| 153 | // o1 = i1 ^ (x1 + s1) |
| 154 | vadd.i32 q1, q1, q9 |
| 155 | veor q1, q1, q5 |
| 156 | |
| 157 | // o2 = i2 ^ (x2 + s2) |
| 158 | vadd.i32 q2, q2, q10 |
| 159 | veor q2, q2, q6 |
| 160 | |
| 161 | // o3 = i3 ^ (x3 + s3) |
| 162 | vadd.i32 q3, q3, q11 |
| 163 | veor q3, q3, q7 |
| 164 | |
| 165 | add ip, r1, #0x20 |
| 166 | vst1.8 {q0-q1}, [r1] |
| 167 | vst1.8 {q2-q3}, [ip] |
| 168 | |
| 169 | bx lr |
| 170 | ENDPROC(chacha20_block_xor_neon) |
| 171 | |
Eric Biggers | d233322 | 2018-09-01 00:17:07 -0700 | [diff] [blame^] | 172 | .align 4 |
| 173 | .Lctrinc: .word 0, 1, 2, 3 |
| 174 | .Lrol8_table: .byte 3, 0, 1, 2, 7, 4, 5, 6 |
| 175 | |
Ard Biesheuvel | dc6ff202 | 2016-12-08 14:28:59 +0000 | [diff] [blame] | 176 | .align 5 |
| 177 | ENTRY(chacha20_4block_xor_neon) |
Eric Biggers | d233322 | 2018-09-01 00:17:07 -0700 | [diff] [blame^] | 178 | push {r4-r5} |
| 179 | mov r4, sp // preserve the stack pointer |
| 180 | sub ip, sp, #0x20 // allocate a 32 byte buffer |
| 181 | bic ip, ip, #0x1f // aligned to 32 bytes |
| 182 | mov sp, ip |
Ard Biesheuvel | dc6ff202 | 2016-12-08 14:28:59 +0000 | [diff] [blame] | 183 | |
| 184 | // r0: Input state matrix, s |
| 185 | // r1: 4 data blocks output, o |
| 186 | // r2: 4 data blocks input, i |
| 187 | |
| 188 | // |
| 189 | // This function encrypts four consecutive ChaCha20 blocks by loading |
| 190 | // the state matrix in NEON registers four times. The algorithm performs |
| 191 | // each operation on the corresponding word of each state matrix, hence |
Eric Biggers | d233322 | 2018-09-01 00:17:07 -0700 | [diff] [blame^] | 192 | // requires no word shuffling. The words are re-interleaved before the |
| 193 | // final addition of the original state and the XORing step. |
Ard Biesheuvel | dc6ff202 | 2016-12-08 14:28:59 +0000 | [diff] [blame] | 194 | // |
| 195 | |
Eric Biggers | d233322 | 2018-09-01 00:17:07 -0700 | [diff] [blame^] | 196 | // x0..15[0-3] = s0..15[0-3] |
| 197 | add ip, r0, #0x20 |
Ard Biesheuvel | dc6ff202 | 2016-12-08 14:28:59 +0000 | [diff] [blame] | 198 | vld1.32 {q0-q1}, [r0] |
Eric Biggers | d233322 | 2018-09-01 00:17:07 -0700 | [diff] [blame^] | 199 | vld1.32 {q2-q3}, [ip] |
Ard Biesheuvel | dc6ff202 | 2016-12-08 14:28:59 +0000 | [diff] [blame] | 200 | |
Eric Biggers | d233322 | 2018-09-01 00:17:07 -0700 | [diff] [blame^] | 201 | adr r5, .Lctrinc |
Ard Biesheuvel | dc6ff202 | 2016-12-08 14:28:59 +0000 | [diff] [blame] | 202 | vdup.32 q15, d7[1] |
| 203 | vdup.32 q14, d7[0] |
Eric Biggers | d233322 | 2018-09-01 00:17:07 -0700 | [diff] [blame^] | 204 | vld1.32 {q4}, [r5, :128] |
Ard Biesheuvel | dc6ff202 | 2016-12-08 14:28:59 +0000 | [diff] [blame] | 205 | vdup.32 q13, d6[1] |
| 206 | vdup.32 q12, d6[0] |
Ard Biesheuvel | dc6ff202 | 2016-12-08 14:28:59 +0000 | [diff] [blame] | 207 | vdup.32 q11, d5[1] |
| 208 | vdup.32 q10, d5[0] |
Eric Biggers | d233322 | 2018-09-01 00:17:07 -0700 | [diff] [blame^] | 209 | vadd.u32 q12, q12, q4 // x12 += counter values 0-3 |
Ard Biesheuvel | dc6ff202 | 2016-12-08 14:28:59 +0000 | [diff] [blame] | 210 | vdup.32 q9, d4[1] |
| 211 | vdup.32 q8, d4[0] |
| 212 | vdup.32 q7, d3[1] |
| 213 | vdup.32 q6, d3[0] |
| 214 | vdup.32 q5, d2[1] |
| 215 | vdup.32 q4, d2[0] |
| 216 | vdup.32 q3, d1[1] |
| 217 | vdup.32 q2, d1[0] |
| 218 | vdup.32 q1, d0[1] |
| 219 | vdup.32 q0, d0[0] |
| 220 | |
Eric Biggers | d233322 | 2018-09-01 00:17:07 -0700 | [diff] [blame^] | 221 | adr ip, .Lrol8_table |
Ard Biesheuvel | dc6ff202 | 2016-12-08 14:28:59 +0000 | [diff] [blame] | 222 | mov r3, #10 |
Eric Biggers | d233322 | 2018-09-01 00:17:07 -0700 | [diff] [blame^] | 223 | b 1f |
Ard Biesheuvel | dc6ff202 | 2016-12-08 14:28:59 +0000 | [diff] [blame] | 224 | |
| 225 | .Ldoubleround4: |
Eric Biggers | d233322 | 2018-09-01 00:17:07 -0700 | [diff] [blame^] | 226 | vld1.32 {q8-q9}, [sp, :256] |
| 227 | 1: |
Ard Biesheuvel | dc6ff202 | 2016-12-08 14:28:59 +0000 | [diff] [blame] | 228 | // x0 += x4, x12 = rotl32(x12 ^ x0, 16) |
| 229 | // x1 += x5, x13 = rotl32(x13 ^ x1, 16) |
| 230 | // x2 += x6, x14 = rotl32(x14 ^ x2, 16) |
| 231 | // x3 += x7, x15 = rotl32(x15 ^ x3, 16) |
| 232 | vadd.i32 q0, q0, q4 |
| 233 | vadd.i32 q1, q1, q5 |
| 234 | vadd.i32 q2, q2, q6 |
| 235 | vadd.i32 q3, q3, q7 |
| 236 | |
| 237 | veor q12, q12, q0 |
| 238 | veor q13, q13, q1 |
| 239 | veor q14, q14, q2 |
| 240 | veor q15, q15, q3 |
| 241 | |
| 242 | vrev32.16 q12, q12 |
| 243 | vrev32.16 q13, q13 |
| 244 | vrev32.16 q14, q14 |
| 245 | vrev32.16 q15, q15 |
| 246 | |
| 247 | // x8 += x12, x4 = rotl32(x4 ^ x8, 12) |
| 248 | // x9 += x13, x5 = rotl32(x5 ^ x9, 12) |
| 249 | // x10 += x14, x6 = rotl32(x6 ^ x10, 12) |
| 250 | // x11 += x15, x7 = rotl32(x7 ^ x11, 12) |
| 251 | vadd.i32 q8, q8, q12 |
| 252 | vadd.i32 q9, q9, q13 |
| 253 | vadd.i32 q10, q10, q14 |
| 254 | vadd.i32 q11, q11, q15 |
| 255 | |
| 256 | vst1.32 {q8-q9}, [sp, :256] |
| 257 | |
| 258 | veor q8, q4, q8 |
| 259 | veor q9, q5, q9 |
| 260 | vshl.u32 q4, q8, #12 |
| 261 | vshl.u32 q5, q9, #12 |
| 262 | vsri.u32 q4, q8, #20 |
| 263 | vsri.u32 q5, q9, #20 |
| 264 | |
| 265 | veor q8, q6, q10 |
| 266 | veor q9, q7, q11 |
| 267 | vshl.u32 q6, q8, #12 |
| 268 | vshl.u32 q7, q9, #12 |
| 269 | vsri.u32 q6, q8, #20 |
| 270 | vsri.u32 q7, q9, #20 |
| 271 | |
| 272 | // x0 += x4, x12 = rotl32(x12 ^ x0, 8) |
| 273 | // x1 += x5, x13 = rotl32(x13 ^ x1, 8) |
| 274 | // x2 += x6, x14 = rotl32(x14 ^ x2, 8) |
| 275 | // x3 += x7, x15 = rotl32(x15 ^ x3, 8) |
Eric Biggers | d233322 | 2018-09-01 00:17:07 -0700 | [diff] [blame^] | 276 | vld1.8 {d16}, [ip, :64] |
Ard Biesheuvel | dc6ff202 | 2016-12-08 14:28:59 +0000 | [diff] [blame] | 277 | vadd.i32 q0, q0, q4 |
| 278 | vadd.i32 q1, q1, q5 |
| 279 | vadd.i32 q2, q2, q6 |
| 280 | vadd.i32 q3, q3, q7 |
| 281 | |
Eric Biggers | d233322 | 2018-09-01 00:17:07 -0700 | [diff] [blame^] | 282 | veor q12, q12, q0 |
| 283 | veor q13, q13, q1 |
| 284 | veor q14, q14, q2 |
| 285 | veor q15, q15, q3 |
Ard Biesheuvel | dc6ff202 | 2016-12-08 14:28:59 +0000 | [diff] [blame] | 286 | |
Eric Biggers | d233322 | 2018-09-01 00:17:07 -0700 | [diff] [blame^] | 287 | vtbl.8 d24, {d24}, d16 |
| 288 | vtbl.8 d25, {d25}, d16 |
| 289 | vtbl.8 d26, {d26}, d16 |
| 290 | vtbl.8 d27, {d27}, d16 |
| 291 | vtbl.8 d28, {d28}, d16 |
| 292 | vtbl.8 d29, {d29}, d16 |
| 293 | vtbl.8 d30, {d30}, d16 |
| 294 | vtbl.8 d31, {d31}, d16 |
Ard Biesheuvel | dc6ff202 | 2016-12-08 14:28:59 +0000 | [diff] [blame] | 295 | |
| 296 | vld1.32 {q8-q9}, [sp, :256] |
| 297 | |
| 298 | // x8 += x12, x4 = rotl32(x4 ^ x8, 7) |
| 299 | // x9 += x13, x5 = rotl32(x5 ^ x9, 7) |
| 300 | // x10 += x14, x6 = rotl32(x6 ^ x10, 7) |
| 301 | // x11 += x15, x7 = rotl32(x7 ^ x11, 7) |
| 302 | vadd.i32 q8, q8, q12 |
| 303 | vadd.i32 q9, q9, q13 |
| 304 | vadd.i32 q10, q10, q14 |
| 305 | vadd.i32 q11, q11, q15 |
| 306 | |
| 307 | vst1.32 {q8-q9}, [sp, :256] |
| 308 | |
| 309 | veor q8, q4, q8 |
| 310 | veor q9, q5, q9 |
| 311 | vshl.u32 q4, q8, #7 |
| 312 | vshl.u32 q5, q9, #7 |
| 313 | vsri.u32 q4, q8, #25 |
| 314 | vsri.u32 q5, q9, #25 |
| 315 | |
| 316 | veor q8, q6, q10 |
| 317 | veor q9, q7, q11 |
| 318 | vshl.u32 q6, q8, #7 |
| 319 | vshl.u32 q7, q9, #7 |
| 320 | vsri.u32 q6, q8, #25 |
| 321 | vsri.u32 q7, q9, #25 |
| 322 | |
| 323 | vld1.32 {q8-q9}, [sp, :256] |
| 324 | |
| 325 | // x0 += x5, x15 = rotl32(x15 ^ x0, 16) |
| 326 | // x1 += x6, x12 = rotl32(x12 ^ x1, 16) |
| 327 | // x2 += x7, x13 = rotl32(x13 ^ x2, 16) |
| 328 | // x3 += x4, x14 = rotl32(x14 ^ x3, 16) |
| 329 | vadd.i32 q0, q0, q5 |
| 330 | vadd.i32 q1, q1, q6 |
| 331 | vadd.i32 q2, q2, q7 |
| 332 | vadd.i32 q3, q3, q4 |
| 333 | |
| 334 | veor q15, q15, q0 |
| 335 | veor q12, q12, q1 |
| 336 | veor q13, q13, q2 |
| 337 | veor q14, q14, q3 |
| 338 | |
| 339 | vrev32.16 q15, q15 |
| 340 | vrev32.16 q12, q12 |
| 341 | vrev32.16 q13, q13 |
| 342 | vrev32.16 q14, q14 |
| 343 | |
| 344 | // x10 += x15, x5 = rotl32(x5 ^ x10, 12) |
| 345 | // x11 += x12, x6 = rotl32(x6 ^ x11, 12) |
| 346 | // x8 += x13, x7 = rotl32(x7 ^ x8, 12) |
| 347 | // x9 += x14, x4 = rotl32(x4 ^ x9, 12) |
| 348 | vadd.i32 q10, q10, q15 |
| 349 | vadd.i32 q11, q11, q12 |
| 350 | vadd.i32 q8, q8, q13 |
| 351 | vadd.i32 q9, q9, q14 |
| 352 | |
| 353 | vst1.32 {q8-q9}, [sp, :256] |
| 354 | |
| 355 | veor q8, q7, q8 |
| 356 | veor q9, q4, q9 |
| 357 | vshl.u32 q7, q8, #12 |
| 358 | vshl.u32 q4, q9, #12 |
| 359 | vsri.u32 q7, q8, #20 |
| 360 | vsri.u32 q4, q9, #20 |
| 361 | |
| 362 | veor q8, q5, q10 |
| 363 | veor q9, q6, q11 |
| 364 | vshl.u32 q5, q8, #12 |
| 365 | vshl.u32 q6, q9, #12 |
| 366 | vsri.u32 q5, q8, #20 |
| 367 | vsri.u32 q6, q9, #20 |
| 368 | |
| 369 | // x0 += x5, x15 = rotl32(x15 ^ x0, 8) |
| 370 | // x1 += x6, x12 = rotl32(x12 ^ x1, 8) |
| 371 | // x2 += x7, x13 = rotl32(x13 ^ x2, 8) |
| 372 | // x3 += x4, x14 = rotl32(x14 ^ x3, 8) |
Eric Biggers | d233322 | 2018-09-01 00:17:07 -0700 | [diff] [blame^] | 373 | vld1.8 {d16}, [ip, :64] |
Ard Biesheuvel | dc6ff202 | 2016-12-08 14:28:59 +0000 | [diff] [blame] | 374 | vadd.i32 q0, q0, q5 |
| 375 | vadd.i32 q1, q1, q6 |
| 376 | vadd.i32 q2, q2, q7 |
| 377 | vadd.i32 q3, q3, q4 |
| 378 | |
Eric Biggers | d233322 | 2018-09-01 00:17:07 -0700 | [diff] [blame^] | 379 | veor q15, q15, q0 |
| 380 | veor q12, q12, q1 |
| 381 | veor q13, q13, q2 |
| 382 | veor q14, q14, q3 |
Ard Biesheuvel | dc6ff202 | 2016-12-08 14:28:59 +0000 | [diff] [blame] | 383 | |
Eric Biggers | d233322 | 2018-09-01 00:17:07 -0700 | [diff] [blame^] | 384 | vtbl.8 d30, {d30}, d16 |
| 385 | vtbl.8 d31, {d31}, d16 |
| 386 | vtbl.8 d24, {d24}, d16 |
| 387 | vtbl.8 d25, {d25}, d16 |
| 388 | vtbl.8 d26, {d26}, d16 |
| 389 | vtbl.8 d27, {d27}, d16 |
| 390 | vtbl.8 d28, {d28}, d16 |
| 391 | vtbl.8 d29, {d29}, d16 |
Ard Biesheuvel | dc6ff202 | 2016-12-08 14:28:59 +0000 | [diff] [blame] | 392 | |
| 393 | vld1.32 {q8-q9}, [sp, :256] |
| 394 | |
| 395 | // x10 += x15, x5 = rotl32(x5 ^ x10, 7) |
| 396 | // x11 += x12, x6 = rotl32(x6 ^ x11, 7) |
| 397 | // x8 += x13, x7 = rotl32(x7 ^ x8, 7) |
| 398 | // x9 += x14, x4 = rotl32(x4 ^ x9, 7) |
| 399 | vadd.i32 q10, q10, q15 |
| 400 | vadd.i32 q11, q11, q12 |
| 401 | vadd.i32 q8, q8, q13 |
| 402 | vadd.i32 q9, q9, q14 |
| 403 | |
| 404 | vst1.32 {q8-q9}, [sp, :256] |
| 405 | |
| 406 | veor q8, q7, q8 |
| 407 | veor q9, q4, q9 |
| 408 | vshl.u32 q7, q8, #7 |
| 409 | vshl.u32 q4, q9, #7 |
| 410 | vsri.u32 q7, q8, #25 |
| 411 | vsri.u32 q4, q9, #25 |
| 412 | |
| 413 | veor q8, q5, q10 |
| 414 | veor q9, q6, q11 |
| 415 | vshl.u32 q5, q8, #7 |
| 416 | vshl.u32 q6, q9, #7 |
| 417 | vsri.u32 q5, q8, #25 |
| 418 | vsri.u32 q6, q9, #25 |
| 419 | |
| 420 | subs r3, r3, #1 |
Eric Biggers | d233322 | 2018-09-01 00:17:07 -0700 | [diff] [blame^] | 421 | bne .Ldoubleround4 |
Ard Biesheuvel | dc6ff202 | 2016-12-08 14:28:59 +0000 | [diff] [blame] | 422 | |
Eric Biggers | d233322 | 2018-09-01 00:17:07 -0700 | [diff] [blame^] | 423 | // x0..7[0-3] are in q0-q7, x10..15[0-3] are in q10-q15. |
| 424 | // x8..9[0-3] are on the stack. |
Ard Biesheuvel | dc6ff202 | 2016-12-08 14:28:59 +0000 | [diff] [blame] | 425 | |
Eric Biggers | d233322 | 2018-09-01 00:17:07 -0700 | [diff] [blame^] | 426 | // Re-interleave the words in the first two rows of each block (x0..7). |
| 427 | // Also add the counter values 0-3 to x12[0-3]. |
| 428 | vld1.32 {q8}, [r5, :128] // load counter values 0-3 |
| 429 | vzip.32 q0, q1 // => (0 1 0 1) (0 1 0 1) |
| 430 | vzip.32 q2, q3 // => (2 3 2 3) (2 3 2 3) |
| 431 | vzip.32 q4, q5 // => (4 5 4 5) (4 5 4 5) |
| 432 | vzip.32 q6, q7 // => (6 7 6 7) (6 7 6 7) |
| 433 | vadd.u32 q12, q8 // x12 += counter values 0-3 |
Ard Biesheuvel | dc6ff202 | 2016-12-08 14:28:59 +0000 | [diff] [blame] | 434 | vswp d1, d4 |
| 435 | vswp d3, d6 |
Eric Biggers | d233322 | 2018-09-01 00:17:07 -0700 | [diff] [blame^] | 436 | vld1.32 {q8-q9}, [r0]! // load s0..7 |
Ard Biesheuvel | dc6ff202 | 2016-12-08 14:28:59 +0000 | [diff] [blame] | 437 | vswp d9, d12 |
| 438 | vswp d11, d14 |
| 439 | |
Eric Biggers | d233322 | 2018-09-01 00:17:07 -0700 | [diff] [blame^] | 440 | // Swap q1 and q4 so that we'll free up consecutive registers (q0-q1) |
| 441 | // after XORing the first 32 bytes. |
| 442 | vswp q1, q4 |
| 443 | |
| 444 | // First two rows of each block are (q0 q1) (q2 q6) (q4 q5) (q3 q7) |
| 445 | |
| 446 | // x0..3[0-3] += s0..3[0-3] (add orig state to 1st row of each block) |
| 447 | vadd.u32 q0, q0, q8 |
| 448 | vadd.u32 q2, q2, q8 |
| 449 | vadd.u32 q4, q4, q8 |
| 450 | vadd.u32 q3, q3, q8 |
| 451 | |
| 452 | // x4..7[0-3] += s4..7[0-3] (add orig state to 2nd row of each block) |
| 453 | vadd.u32 q1, q1, q9 |
| 454 | vadd.u32 q6, q6, q9 |
| 455 | vadd.u32 q5, q5, q9 |
| 456 | vadd.u32 q7, q7, q9 |
| 457 | |
| 458 | // XOR first 32 bytes using keystream from first two rows of first block |
Ard Biesheuvel | dc6ff202 | 2016-12-08 14:28:59 +0000 | [diff] [blame] | 459 | vld1.8 {q8-q9}, [r2]! |
| 460 | veor q8, q8, q0 |
Eric Biggers | d233322 | 2018-09-01 00:17:07 -0700 | [diff] [blame^] | 461 | veor q9, q9, q1 |
Ard Biesheuvel | dc6ff202 | 2016-12-08 14:28:59 +0000 | [diff] [blame] | 462 | vst1.8 {q8-q9}, [r1]! |
| 463 | |
Eric Biggers | d233322 | 2018-09-01 00:17:07 -0700 | [diff] [blame^] | 464 | // Re-interleave the words in the last two rows of each block (x8..15). |
Ard Biesheuvel | dc6ff202 | 2016-12-08 14:28:59 +0000 | [diff] [blame] | 465 | vld1.32 {q8-q9}, [sp, :256] |
Eric Biggers | d233322 | 2018-09-01 00:17:07 -0700 | [diff] [blame^] | 466 | vzip.32 q12, q13 // => (12 13 12 13) (12 13 12 13) |
| 467 | vzip.32 q14, q15 // => (14 15 14 15) (14 15 14 15) |
| 468 | vzip.32 q8, q9 // => (8 9 8 9) (8 9 8 9) |
| 469 | vzip.32 q10, q11 // => (10 11 10 11) (10 11 10 11) |
| 470 | vld1.32 {q0-q1}, [r0] // load s8..15 |
Ard Biesheuvel | dc6ff202 | 2016-12-08 14:28:59 +0000 | [diff] [blame] | 471 | vswp d25, d28 |
| 472 | vswp d27, d30 |
Eric Biggers | d233322 | 2018-09-01 00:17:07 -0700 | [diff] [blame^] | 473 | vswp d17, d20 |
| 474 | vswp d19, d22 |
Ard Biesheuvel | dc6ff202 | 2016-12-08 14:28:59 +0000 | [diff] [blame] | 475 | |
Eric Biggers | d233322 | 2018-09-01 00:17:07 -0700 | [diff] [blame^] | 476 | // Last two rows of each block are (q8 q12) (q10 q14) (q9 q13) (q11 q15) |
| 477 | |
| 478 | // x8..11[0-3] += s8..11[0-3] (add orig state to 3rd row of each block) |
| 479 | vadd.u32 q8, q8, q0 |
| 480 | vadd.u32 q10, q10, q0 |
| 481 | vadd.u32 q9, q9, q0 |
| 482 | vadd.u32 q11, q11, q0 |
| 483 | |
| 484 | // x12..15[0-3] += s12..15[0-3] (add orig state to 4th row of each block) |
| 485 | vadd.u32 q12, q12, q1 |
| 486 | vadd.u32 q14, q14, q1 |
| 487 | vadd.u32 q13, q13, q1 |
| 488 | vadd.u32 q15, q15, q1 |
| 489 | |
| 490 | // XOR the rest of the data with the keystream |
Ard Biesheuvel | dc6ff202 | 2016-12-08 14:28:59 +0000 | [diff] [blame] | 491 | |
| 492 | vld1.8 {q0-q1}, [r2]! |
| 493 | veor q0, q0, q8 |
| 494 | veor q1, q1, q12 |
| 495 | vst1.8 {q0-q1}, [r1]! |
| 496 | |
| 497 | vld1.8 {q0-q1}, [r2]! |
| 498 | veor q0, q0, q2 |
| 499 | veor q1, q1, q6 |
| 500 | vst1.8 {q0-q1}, [r1]! |
| 501 | |
| 502 | vld1.8 {q0-q1}, [r2]! |
| 503 | veor q0, q0, q10 |
| 504 | veor q1, q1, q14 |
| 505 | vst1.8 {q0-q1}, [r1]! |
| 506 | |
| 507 | vld1.8 {q0-q1}, [r2]! |
| 508 | veor q0, q0, q4 |
| 509 | veor q1, q1, q5 |
| 510 | vst1.8 {q0-q1}, [r1]! |
| 511 | |
| 512 | vld1.8 {q0-q1}, [r2]! |
| 513 | veor q0, q0, q9 |
| 514 | veor q1, q1, q13 |
| 515 | vst1.8 {q0-q1}, [r1]! |
| 516 | |
| 517 | vld1.8 {q0-q1}, [r2]! |
| 518 | veor q0, q0, q3 |
| 519 | veor q1, q1, q7 |
| 520 | vst1.8 {q0-q1}, [r1]! |
| 521 | |
| 522 | vld1.8 {q0-q1}, [r2] |
Eric Biggers | d233322 | 2018-09-01 00:17:07 -0700 | [diff] [blame^] | 523 | mov sp, r4 // restore original stack pointer |
Ard Biesheuvel | dc6ff202 | 2016-12-08 14:28:59 +0000 | [diff] [blame] | 524 | veor q0, q0, q11 |
| 525 | veor q1, q1, q15 |
| 526 | vst1.8 {q0-q1}, [r1] |
| 527 | |
Eric Biggers | d233322 | 2018-09-01 00:17:07 -0700 | [diff] [blame^] | 528 | pop {r4-r5} |
| 529 | bx lr |
Ard Biesheuvel | dc6ff202 | 2016-12-08 14:28:59 +0000 | [diff] [blame] | 530 | ENDPROC(chacha20_4block_xor_neon) |