1 /* 2 * Implement fast Fletcher4 with NEON instructions. (aarch64) 3 * 4 * Use the 128-bit NEON SIMD instructions and registers to compute 5 * Fletcher4 in two incremental 64-bit parallel accumulator streams, 6 * and then combine the streams to form the final four checksum words. 7 * This implementation is a derivative of the AVX SIMD implementation by 8 * James Guilford and Jinshan Xiong from Intel (see zfs_fletcher_intel.c). 9 * 10 * Copyright (C) 2016 Romain Dolbeau. 11 * 12 * Authors: 13 * Romain Dolbeau <romain.dolbeau@atos.net> 14 * 15 * This software is available to you under a choice of one of two 16 * licenses. You may choose to be licensed under the terms of the GNU 17 * General Public License (GPL) Version 2, available from the file 18 * COPYING in the main directory of this source tree, or the 19 * OpenIB.org BSD license below: 20 * 21 * Redistribution and use in source and binary forms, with or 22 * without modification, are permitted provided that the following 23 * conditions are met: 24 * 25 * - Redistributions of source code must retain the above 26 * copyright notice, this list of conditions and the following 27 * disclaimer. 28 * 29 * - Redistributions in binary form must reproduce the above 30 * copyright notice, this list of conditions and the following 31 * disclaimer in the documentation and/or other materials 32 * provided with the distribution. 33 * 34 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, 35 * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF 36 * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND 37 * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS 38 * BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN 39 * ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN 40 * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE 41 * SOFTWARE. 42 */ 43 44 #if defined(__aarch64__) 45 46 #include <sys/simd.h> 47 #include <sys/spa_checksum.h> 48 #include <sys/string.h> 49 #include <zfs_fletcher.h> 50 51 static void 52 fletcher_4_aarch64_neon_init(fletcher_4_ctx_t *ctx) 53 { 54 memset(ctx->aarch64_neon, 0, 4 * sizeof (zfs_fletcher_aarch64_neon_t)); 55 } 56 57 static void 58 fletcher_4_aarch64_neon_fini(fletcher_4_ctx_t *ctx, zio_cksum_t *zcp) 59 { 60 uint64_t A, B, C, D; 61 A = ctx->aarch64_neon[0].v[0] + ctx->aarch64_neon[0].v[1]; 62 B = 2 * ctx->aarch64_neon[1].v[0] + 2 * ctx->aarch64_neon[1].v[1] - 63 ctx->aarch64_neon[0].v[1]; 64 C = 4 * ctx->aarch64_neon[2].v[0] - ctx->aarch64_neon[1].v[0] + 65 4 * ctx->aarch64_neon[2].v[1] - 3 * ctx->aarch64_neon[1].v[1]; 66 D = 8 * ctx->aarch64_neon[3].v[0] - 4 * ctx->aarch64_neon[2].v[0] + 67 8 * ctx->aarch64_neon[3].v[1] - 8 * ctx->aarch64_neon[2].v[1] + 68 ctx->aarch64_neon[1].v[1]; 69 ZIO_SET_CHECKSUM(zcp, A, B, C, D); 70 } 71 72 #define NEON_INIT_LOOP() \ 73 asm("eor %[ZERO].16b,%[ZERO].16b,%[ZERO].16b\n" \ 74 "ld1 { %[ACC0].4s }, %[CTX0]\n" \ 75 "ld1 { %[ACC1].4s }, %[CTX1]\n" \ 76 "ld1 { %[ACC2].4s }, %[CTX2]\n" \ 77 "ld1 { %[ACC3].4s }, %[CTX3]\n" \ 78 : [ZERO] "=w" (ZERO), \ 79 [ACC0] "=w" (ACC0), [ACC1] "=w" (ACC1), \ 80 [ACC2] "=w" (ACC2), [ACC3] "=w" (ACC3) \ 81 : [CTX0] "Q" (ctx->aarch64_neon[0]), \ 82 [CTX1] "Q" (ctx->aarch64_neon[1]), \ 83 [CTX2] "Q" (ctx->aarch64_neon[2]), \ 84 [CTX3] "Q" (ctx->aarch64_neon[3])) 85 86 #define NEON_DO_REVERSE "rev32 %[SRC].16b, %[SRC].16b\n" 87 88 #define NEON_DONT_REVERSE "" 89 90 #define NEON_MAIN_LOOP(REVERSE) \ 91 asm("ld1 { %[SRC].4s }, %[IP]\n" \ 92 REVERSE \ 93 "zip1 %[TMP1].4s, %[SRC].4s, %[ZERO].4s\n" \ 94 "zip2 %[TMP2].4s, %[SRC].4s, %[ZERO].4s\n" \ 95 "add %[ACC0].2d, %[ACC0].2d, %[TMP1].2d\n" \ 96 "add %[ACC1].2d, %[ACC1].2d, %[ACC0].2d\n" \ 97 "add %[ACC2].2d, %[ACC2].2d, %[ACC1].2d\n" \ 98 "add %[ACC3].2d, %[ACC3].2d, %[ACC2].2d\n" \ 99 "add %[ACC0].2d, %[ACC0].2d, %[TMP2].2d\n" \ 100 "add %[ACC1].2d, %[ACC1].2d, %[ACC0].2d\n" \ 101 "add %[ACC2].2d, %[ACC2].2d, %[ACC1].2d\n" \ 102 "add %[ACC3].2d, %[ACC3].2d, %[ACC2].2d\n" \ 103 : [SRC] "=&w" (SRC), \ 104 [TMP1] "=&w" (TMP1), [TMP2] "=&w" (TMP2), \ 105 [ACC0] "+w" (ACC0), [ACC1] "+w" (ACC1), \ 106 [ACC2] "+w" (ACC2), [ACC3] "+w" (ACC3) \ 107 : [ZERO] "w" (ZERO), [IP] "Q" (*ip)) 108 109 #define NEON_FINI_LOOP() \ 110 asm("st1 { %[ACC0].4s },%[DST0]\n" \ 111 "st1 { %[ACC1].4s },%[DST1]\n" \ 112 "st1 { %[ACC2].4s },%[DST2]\n" \ 113 "st1 { %[ACC3].4s },%[DST3]\n" \ 114 : [DST0] "=Q" (ctx->aarch64_neon[0]), \ 115 [DST1] "=Q" (ctx->aarch64_neon[1]), \ 116 [DST2] "=Q" (ctx->aarch64_neon[2]), \ 117 [DST3] "=Q" (ctx->aarch64_neon[3]) \ 118 : [ACC0] "w" (ACC0), [ACC1] "w" (ACC1), \ 119 [ACC2] "w" (ACC2), [ACC3] "w" (ACC3)) 120 121 static void 122 fletcher_4_aarch64_neon_native(fletcher_4_ctx_t *ctx, 123 const void *buf, uint64_t size) 124 { 125 const uint64_t *ip = buf; 126 const uint64_t *ipend = (uint64_t *)((uint8_t *)ip + size); 127 #if defined(_KERNEL) 128 register unsigned char ZERO asm("v0") __attribute__((vector_size(16))); 129 register unsigned char ACC0 asm("v1") __attribute__((vector_size(16))); 130 register unsigned char ACC1 asm("v2") __attribute__((vector_size(16))); 131 register unsigned char ACC2 asm("v3") __attribute__((vector_size(16))); 132 register unsigned char ACC3 asm("v4") __attribute__((vector_size(16))); 133 register unsigned char TMP1 asm("v5") __attribute__((vector_size(16))); 134 register unsigned char TMP2 asm("v6") __attribute__((vector_size(16))); 135 register unsigned char SRC asm("v7") __attribute__((vector_size(16))); 136 #else 137 unsigned char ZERO __attribute__((vector_size(16))); 138 unsigned char ACC0 __attribute__((vector_size(16))); 139 unsigned char ACC1 __attribute__((vector_size(16))); 140 unsigned char ACC2 __attribute__((vector_size(16))); 141 unsigned char ACC3 __attribute__((vector_size(16))); 142 unsigned char TMP1 __attribute__((vector_size(16))); 143 unsigned char TMP2 __attribute__((vector_size(16))); 144 unsigned char SRC __attribute__((vector_size(16))); 145 #endif 146 147 NEON_INIT_LOOP(); 148 149 do { 150 NEON_MAIN_LOOP(NEON_DONT_REVERSE); 151 } while ((ip += 2) < ipend); 152 153 NEON_FINI_LOOP(); 154 } 155 156 static void 157 fletcher_4_aarch64_neon_byteswap(fletcher_4_ctx_t *ctx, 158 const void *buf, uint64_t size) 159 { 160 const uint64_t *ip = buf; 161 const uint64_t *ipend = (uint64_t *)((uint8_t *)ip + size); 162 #if defined(_KERNEL) 163 register unsigned char ZERO asm("v0") __attribute__((vector_size(16))); 164 register unsigned char ACC0 asm("v1") __attribute__((vector_size(16))); 165 register unsigned char ACC1 asm("v2") __attribute__((vector_size(16))); 166 register unsigned char ACC2 asm("v3") __attribute__((vector_size(16))); 167 register unsigned char ACC3 asm("v4") __attribute__((vector_size(16))); 168 register unsigned char TMP1 asm("v5") __attribute__((vector_size(16))); 169 register unsigned char TMP2 asm("v6") __attribute__((vector_size(16))); 170 register unsigned char SRC asm("v7") __attribute__((vector_size(16))); 171 #else 172 unsigned char ZERO __attribute__((vector_size(16))); 173 unsigned char ACC0 __attribute__((vector_size(16))); 174 unsigned char ACC1 __attribute__((vector_size(16))); 175 unsigned char ACC2 __attribute__((vector_size(16))); 176 unsigned char ACC3 __attribute__((vector_size(16))); 177 unsigned char TMP1 __attribute__((vector_size(16))); 178 unsigned char TMP2 __attribute__((vector_size(16))); 179 unsigned char SRC __attribute__((vector_size(16))); 180 #endif 181 182 NEON_INIT_LOOP(); 183 184 do { 185 NEON_MAIN_LOOP(NEON_DO_REVERSE); 186 } while ((ip += 2) < ipend); 187 188 NEON_FINI_LOOP(); 189 } 190 191 static boolean_t fletcher_4_aarch64_neon_valid(void) 192 { 193 return (kfpu_allowed()); 194 } 195 196 const fletcher_4_ops_t fletcher_4_aarch64_neon_ops = { 197 .init_native = fletcher_4_aarch64_neon_init, 198 .compute_native = fletcher_4_aarch64_neon_native, 199 .fini_native = fletcher_4_aarch64_neon_fini, 200 .init_byteswap = fletcher_4_aarch64_neon_init, 201 .compute_byteswap = fletcher_4_aarch64_neon_byteswap, 202 .fini_byteswap = fletcher_4_aarch64_neon_fini, 203 .valid = fletcher_4_aarch64_neon_valid, 204 .uses_fpu = B_TRUE, 205 .name = "aarch64_neon" 206 }; 207 208 #endif /* defined(__aarch64__) */ 209