Yazen Ghannam | f6f203f | 2014-11-19 11:19:37 -0600 | [diff] [blame] | 1 | /* |
| 2 | * crc32-arm64.c - CRC32 and CRC32C using optional ARMv8 instructions |
| 3 | * |
| 4 | * Module based on crypto/crc32c_generic.c |
| 5 | * |
| 6 | * CRC32 loop taken from Ed Nevill's Hadoop CRC patch |
| 7 | * http://mail-archives.apache.org/mod_mbox/hadoop-common-dev/201406.mbox/%3C1403687030.3355.19.camel%40localhost.localdomain%3E |
| 8 | * |
| 9 | * Using inline assembly instead of intrinsics in order to be backwards |
| 10 | * compatible with older compilers. |
| 11 | * |
| 12 | * Copyright (C) 2014 Linaro Ltd <yazen.ghannam@linaro.org> |
| 13 | * |
| 14 | * This program is free software; you can redistribute it and/or modify |
| 15 | * it under the terms of the GNU General Public License version 2 as |
| 16 | * published by the Free Software Foundation. |
| 17 | */ |
| 18 | |
| 19 | #include <linux/unaligned/access_ok.h> |
| 20 | #include <linux/cpufeature.h> |
| 21 | #include <linux/init.h> |
| 22 | #include <linux/kernel.h> |
| 23 | #include <linux/module.h> |
| 24 | #include <linux/string.h> |
| 25 | |
| 26 | #include <crypto/internal/hash.h> |
| 27 | |
| 28 | MODULE_AUTHOR("Yazen Ghannam <yazen.ghannam@linaro.org>"); |
| 29 | MODULE_DESCRIPTION("CRC32 and CRC32C using optional ARMv8 instructions"); |
| 30 | MODULE_LICENSE("GPL v2"); |
| 31 | |
| 32 | #define CRC32X(crc, value) __asm__("crc32x %w[c], %w[c], %x[v]":[c]"+r"(crc):[v]"r"(value)) |
| 33 | #define CRC32W(crc, value) __asm__("crc32w %w[c], %w[c], %w[v]":[c]"+r"(crc):[v]"r"(value)) |
| 34 | #define CRC32H(crc, value) __asm__("crc32h %w[c], %w[c], %w[v]":[c]"+r"(crc):[v]"r"(value)) |
| 35 | #define CRC32B(crc, value) __asm__("crc32b %w[c], %w[c], %w[v]":[c]"+r"(crc):[v]"r"(value)) |
| 36 | #define CRC32CX(crc, value) __asm__("crc32cx %w[c], %w[c], %x[v]":[c]"+r"(crc):[v]"r"(value)) |
| 37 | #define CRC32CW(crc, value) __asm__("crc32cw %w[c], %w[c], %w[v]":[c]"+r"(crc):[v]"r"(value)) |
| 38 | #define CRC32CH(crc, value) __asm__("crc32ch %w[c], %w[c], %w[v]":[c]"+r"(crc):[v]"r"(value)) |
| 39 | #define CRC32CB(crc, value) __asm__("crc32cb %w[c], %w[c], %w[v]":[c]"+r"(crc):[v]"r"(value)) |
| 40 | |
| 41 | static u32 crc32_arm64_le_hw(u32 crc, const u8 *p, unsigned int len) |
| 42 | { |
| 43 | s64 length = len; |
| 44 | |
| 45 | while ((length -= sizeof(u64)) >= 0) { |
| 46 | CRC32X(crc, get_unaligned_le64(p)); |
| 47 | p += sizeof(u64); |
| 48 | } |
| 49 | |
| 50 | /* The following is more efficient than the straight loop */ |
| 51 | if (length & sizeof(u32)) { |
| 52 | CRC32W(crc, get_unaligned_le32(p)); |
| 53 | p += sizeof(u32); |
| 54 | } |
| 55 | if (length & sizeof(u16)) { |
| 56 | CRC32H(crc, get_unaligned_le16(p)); |
| 57 | p += sizeof(u16); |
| 58 | } |
| 59 | if (length & sizeof(u8)) |
| 60 | CRC32B(crc, *p); |
| 61 | |
| 62 | return crc; |
| 63 | } |
| 64 | |
| 65 | static u32 crc32c_arm64_le_hw(u32 crc, const u8 *p, unsigned int len) |
| 66 | { |
| 67 | s64 length = len; |
| 68 | |
| 69 | while ((length -= sizeof(u64)) >= 0) { |
| 70 | CRC32CX(crc, get_unaligned_le64(p)); |
| 71 | p += sizeof(u64); |
| 72 | } |
| 73 | |
| 74 | /* The following is more efficient than the straight loop */ |
| 75 | if (length & sizeof(u32)) { |
| 76 | CRC32CW(crc, get_unaligned_le32(p)); |
| 77 | p += sizeof(u32); |
| 78 | } |
| 79 | if (length & sizeof(u16)) { |
| 80 | CRC32CH(crc, get_unaligned_le16(p)); |
| 81 | p += sizeof(u16); |
| 82 | } |
| 83 | if (length & sizeof(u8)) |
| 84 | CRC32CB(crc, *p); |
| 85 | |
| 86 | return crc; |
| 87 | } |
| 88 | |
| 89 | #define CHKSUM_BLOCK_SIZE 1 |
| 90 | #define CHKSUM_DIGEST_SIZE 4 |
| 91 | |
| 92 | struct chksum_ctx { |
| 93 | u32 key; |
| 94 | }; |
| 95 | |
| 96 | struct chksum_desc_ctx { |
| 97 | u32 crc; |
| 98 | }; |
| 99 | |
| 100 | static int chksum_init(struct shash_desc *desc) |
| 101 | { |
| 102 | struct chksum_ctx *mctx = crypto_shash_ctx(desc->tfm); |
| 103 | struct chksum_desc_ctx *ctx = shash_desc_ctx(desc); |
| 104 | |
| 105 | ctx->crc = mctx->key; |
| 106 | |
| 107 | return 0; |
| 108 | } |
| 109 | |
| 110 | /* |
| 111 | * Setting the seed allows arbitrary accumulators and flexible XOR policy |
| 112 | * If your algorithm starts with ~0, then XOR with ~0 before you set |
| 113 | * the seed. |
| 114 | */ |
| 115 | static int chksum_setkey(struct crypto_shash *tfm, const u8 *key, |
| 116 | unsigned int keylen) |
| 117 | { |
| 118 | struct chksum_ctx *mctx = crypto_shash_ctx(tfm); |
| 119 | |
| 120 | if (keylen != sizeof(mctx->key)) { |
| 121 | crypto_shash_set_flags(tfm, CRYPTO_TFM_RES_BAD_KEY_LEN); |
| 122 | return -EINVAL; |
| 123 | } |
| 124 | mctx->key = get_unaligned_le32(key); |
| 125 | return 0; |
| 126 | } |
| 127 | |
| 128 | static int chksum_update(struct shash_desc *desc, const u8 *data, |
| 129 | unsigned int length) |
| 130 | { |
| 131 | struct chksum_desc_ctx *ctx = shash_desc_ctx(desc); |
| 132 | |
| 133 | ctx->crc = crc32_arm64_le_hw(ctx->crc, data, length); |
| 134 | return 0; |
| 135 | } |
| 136 | |
| 137 | static int chksumc_update(struct shash_desc *desc, const u8 *data, |
| 138 | unsigned int length) |
| 139 | { |
| 140 | struct chksum_desc_ctx *ctx = shash_desc_ctx(desc); |
| 141 | |
| 142 | ctx->crc = crc32c_arm64_le_hw(ctx->crc, data, length); |
| 143 | return 0; |
| 144 | } |
| 145 | |
| 146 | static int chksum_final(struct shash_desc *desc, u8 *out) |
| 147 | { |
| 148 | struct chksum_desc_ctx *ctx = shash_desc_ctx(desc); |
| 149 | |
| 150 | put_unaligned_le32(~ctx->crc, out); |
| 151 | return 0; |
| 152 | } |
| 153 | |
| 154 | static int __chksum_finup(u32 crc, const u8 *data, unsigned int len, u8 *out) |
| 155 | { |
| 156 | put_unaligned_le32(~crc32_arm64_le_hw(crc, data, len), out); |
| 157 | return 0; |
| 158 | } |
| 159 | |
| 160 | static int __chksumc_finup(u32 crc, const u8 *data, unsigned int len, u8 *out) |
| 161 | { |
| 162 | put_unaligned_le32(~crc32c_arm64_le_hw(crc, data, len), out); |
| 163 | return 0; |
| 164 | } |
| 165 | |
| 166 | static int chksum_finup(struct shash_desc *desc, const u8 *data, |
| 167 | unsigned int len, u8 *out) |
| 168 | { |
| 169 | struct chksum_desc_ctx *ctx = shash_desc_ctx(desc); |
| 170 | |
| 171 | return __chksum_finup(ctx->crc, data, len, out); |
| 172 | } |
| 173 | |
| 174 | static int chksumc_finup(struct shash_desc *desc, const u8 *data, |
| 175 | unsigned int len, u8 *out) |
| 176 | { |
| 177 | struct chksum_desc_ctx *ctx = shash_desc_ctx(desc); |
| 178 | |
| 179 | return __chksumc_finup(ctx->crc, data, len, out); |
| 180 | } |
| 181 | |
| 182 | static int chksum_digest(struct shash_desc *desc, const u8 *data, |
| 183 | unsigned int length, u8 *out) |
| 184 | { |
| 185 | struct chksum_ctx *mctx = crypto_shash_ctx(desc->tfm); |
| 186 | |
| 187 | return __chksum_finup(mctx->key, data, length, out); |
| 188 | } |
| 189 | |
| 190 | static int chksumc_digest(struct shash_desc *desc, const u8 *data, |
| 191 | unsigned int length, u8 *out) |
| 192 | { |
| 193 | struct chksum_ctx *mctx = crypto_shash_ctx(desc->tfm); |
| 194 | |
| 195 | return __chksumc_finup(mctx->key, data, length, out); |
| 196 | } |
| 197 | |
| 198 | static int crc32_cra_init(struct crypto_tfm *tfm) |
| 199 | { |
| 200 | struct chksum_ctx *mctx = crypto_tfm_ctx(tfm); |
| 201 | |
| 202 | mctx->key = ~0; |
| 203 | return 0; |
| 204 | } |
| 205 | |
| 206 | static struct shash_alg crc32_alg = { |
| 207 | .digestsize = CHKSUM_DIGEST_SIZE, |
| 208 | .setkey = chksum_setkey, |
| 209 | .init = chksum_init, |
| 210 | .update = chksum_update, |
| 211 | .final = chksum_final, |
| 212 | .finup = chksum_finup, |
| 213 | .digest = chksum_digest, |
| 214 | .descsize = sizeof(struct chksum_desc_ctx), |
| 215 | .base = { |
| 216 | .cra_name = "crc32", |
| 217 | .cra_driver_name = "crc32-arm64-hw", |
| 218 | .cra_priority = 300, |
| 219 | .cra_blocksize = CHKSUM_BLOCK_SIZE, |
| 220 | .cra_alignmask = 0, |
| 221 | .cra_ctxsize = sizeof(struct chksum_ctx), |
| 222 | .cra_module = THIS_MODULE, |
| 223 | .cra_init = crc32_cra_init, |
| 224 | } |
| 225 | }; |
| 226 | |
| 227 | static struct shash_alg crc32c_alg = { |
| 228 | .digestsize = CHKSUM_DIGEST_SIZE, |
| 229 | .setkey = chksum_setkey, |
| 230 | .init = chksum_init, |
| 231 | .update = chksumc_update, |
| 232 | .final = chksum_final, |
| 233 | .finup = chksumc_finup, |
| 234 | .digest = chksumc_digest, |
| 235 | .descsize = sizeof(struct chksum_desc_ctx), |
| 236 | .base = { |
| 237 | .cra_name = "crc32c", |
| 238 | .cra_driver_name = "crc32c-arm64-hw", |
| 239 | .cra_priority = 300, |
| 240 | .cra_blocksize = CHKSUM_BLOCK_SIZE, |
| 241 | .cra_alignmask = 0, |
| 242 | .cra_ctxsize = sizeof(struct chksum_ctx), |
| 243 | .cra_module = THIS_MODULE, |
| 244 | .cra_init = crc32_cra_init, |
| 245 | } |
| 246 | }; |
| 247 | |
| 248 | static int __init crc32_mod_init(void) |
| 249 | { |
| 250 | int err; |
| 251 | |
| 252 | err = crypto_register_shash(&crc32_alg); |
| 253 | |
| 254 | if (err) |
| 255 | return err; |
| 256 | |
| 257 | err = crypto_register_shash(&crc32c_alg); |
| 258 | |
| 259 | if (err) { |
| 260 | crypto_unregister_shash(&crc32_alg); |
| 261 | return err; |
| 262 | } |
| 263 | |
| 264 | return 0; |
| 265 | } |
| 266 | |
| 267 | static void __exit crc32_mod_exit(void) |
| 268 | { |
| 269 | crypto_unregister_shash(&crc32_alg); |
| 270 | crypto_unregister_shash(&crc32c_alg); |
| 271 | } |
| 272 | |
| 273 | module_cpu_feature_match(CRC32, crc32_mod_init); |
| 274 | module_exit(crc32_mod_exit); |