1 // SPDX-License-Identifier: GPL-2.0-or-later 2 /* 3 * x64 SIMD accelerated ChaCha and XChaCha stream ciphers, 4 * including ChaCha20 (RFC7539) 5 * 6 * Copyright (C) 2015 Martin Willi 7 */ 8 9 #include <crypto/algapi.h> 10 #include <crypto/internal/chacha.h> 11 #include <crypto/internal/simd.h> 12 #include <crypto/internal/skcipher.h> 13 #include <linux/kernel.h> 14 #include <linux/module.h> 15 #include <asm/simd.h> 16 17 #define CHACHA_STATE_ALIGN 16 18 19 asmlinkage void chacha_block_xor_ssse3(u32 *state, u8 *dst, const u8 *src, 20 unsigned int len, int nrounds); 21 asmlinkage void chacha_4block_xor_ssse3(u32 *state, u8 *dst, const u8 *src, 22 unsigned int len, int nrounds); 23 asmlinkage void hchacha_block_ssse3(const u32 *state, u32 *out, int nrounds); 24 25 asmlinkage void chacha_2block_xor_avx2(u32 *state, u8 *dst, const u8 *src, 26 unsigned int len, int nrounds); 27 asmlinkage void chacha_4block_xor_avx2(u32 *state, u8 *dst, const u8 *src, 28 unsigned int len, int nrounds); 29 asmlinkage void chacha_8block_xor_avx2(u32 *state, u8 *dst, const u8 *src, 30 unsigned int len, int nrounds); 31 32 asmlinkage void chacha_2block_xor_avx512vl(u32 *state, u8 *dst, const u8 *src, 33 unsigned int len, int nrounds); 34 asmlinkage void chacha_4block_xor_avx512vl(u32 *state, u8 *dst, const u8 *src, 35 unsigned int len, int nrounds); 36 asmlinkage void chacha_8block_xor_avx512vl(u32 *state, u8 *dst, const u8 *src, 37 unsigned int len, int nrounds); 38 39 static __ro_after_init DEFINE_STATIC_KEY_FALSE(chacha_use_simd); 40 static __ro_after_init DEFINE_STATIC_KEY_FALSE(chacha_use_avx2); 41 static __ro_after_init DEFINE_STATIC_KEY_FALSE(chacha_use_avx512vl); 42 43 static unsigned int chacha_advance(unsigned int len, unsigned int maxblocks) 44 { 45 len = min(len, maxblocks * CHACHA_BLOCK_SIZE); 46 return round_up(len, CHACHA_BLOCK_SIZE) / CHACHA_BLOCK_SIZE; 47 } 48 49 static void chacha_dosimd(u32 *state, u8 *dst, const u8 *src, 50 unsigned int bytes, int nrounds) 51 { 52 if (IS_ENABLED(CONFIG_AS_AVX512) && 53 static_branch_likely(&chacha_use_avx512vl)) { 54 while (bytes >= CHACHA_BLOCK_SIZE * 8) { 55 chacha_8block_xor_avx512vl(state, dst, src, bytes, 56 nrounds); 57 bytes -= CHACHA_BLOCK_SIZE * 8; 58 src += CHACHA_BLOCK_SIZE * 8; 59 dst += CHACHA_BLOCK_SIZE * 8; 60 state[12] += 8; 61 } 62 if (bytes > CHACHA_BLOCK_SIZE * 4) { 63 chacha_8block_xor_avx512vl(state, dst, src, bytes, 64 nrounds); 65 state[12] += chacha_advance(bytes, 8); 66 return; 67 } 68 if (bytes > CHACHA_BLOCK_SIZE * 2) { 69 chacha_4block_xor_avx512vl(state, dst, src, bytes, 70 nrounds); 71 state[12] += chacha_advance(bytes, 4); 72 return; 73 } 74 if (bytes) { 75 chacha_2block_xor_avx512vl(state, dst, src, bytes, 76 nrounds); 77 state[12] += chacha_advance(bytes, 2); 78 return; 79 } 80 } 81 82 if (IS_ENABLED(CONFIG_AS_AVX2) && 83 static_branch_likely(&chacha_use_avx2)) { 84 while (bytes >= CHACHA_BLOCK_SIZE * 8) { 85 chacha_8block_xor_avx2(state, dst, src, bytes, nrounds); 86 bytes -= CHACHA_BLOCK_SIZE * 8; 87 src += CHACHA_BLOCK_SIZE * 8; 88 dst += CHACHA_BLOCK_SIZE * 8; 89 state[12] += 8; 90 } 91 if (bytes > CHACHA_BLOCK_SIZE * 4) { 92 chacha_8block_xor_avx2(state, dst, src, bytes, nrounds); 93 state[12] += chacha_advance(bytes, 8); 94 return; 95 } 96 if (bytes > CHACHA_BLOCK_SIZE * 2) { 97 chacha_4block_xor_avx2(state, dst, src, bytes, nrounds); 98 state[12] += chacha_advance(bytes, 4); 99 return; 100 } 101 if (bytes > CHACHA_BLOCK_SIZE) { 102 chacha_2block_xor_avx2(state, dst, src, bytes, nrounds); 103 state[12] += chacha_advance(bytes, 2); 104 return; 105 } 106 } 107 108 while (bytes >= CHACHA_BLOCK_SIZE * 4) { 109 chacha_4block_xor_ssse3(state, dst, src, bytes, nrounds); 110 bytes -= CHACHA_BLOCK_SIZE * 4; 111 src += CHACHA_BLOCK_SIZE * 4; 112 dst += CHACHA_BLOCK_SIZE * 4; 113 state[12] += 4; 114 } 115 if (bytes > CHACHA_BLOCK_SIZE) { 116 chacha_4block_xor_ssse3(state, dst, src, bytes, nrounds); 117 state[12] += chacha_advance(bytes, 4); 118 return; 119 } 120 if (bytes) { 121 chacha_block_xor_ssse3(state, dst, src, bytes, nrounds); 122 state[12]++; 123 } 124 } 125 126 void hchacha_block_arch(const u32 *state, u32 *stream, int nrounds) 127 { 128 state = PTR_ALIGN(state, CHACHA_STATE_ALIGN); 129 130 if (!static_branch_likely(&chacha_use_simd) || !crypto_simd_usable()) { 131 hchacha_block_generic(state, stream, nrounds); 132 } else { 133 kernel_fpu_begin(); 134 hchacha_block_ssse3(state, stream, nrounds); 135 kernel_fpu_end(); 136 } 137 } 138 EXPORT_SYMBOL(hchacha_block_arch); 139 140 void chacha_init_arch(u32 *state, const u32 *key, const u8 *iv) 141 { 142 state = PTR_ALIGN(state, CHACHA_STATE_ALIGN); 143 144 chacha_init_generic(state, key, iv); 145 } 146 EXPORT_SYMBOL(chacha_init_arch); 147 148 void chacha_crypt_arch(u32 *state, u8 *dst, const u8 *src, unsigned int bytes, 149 int nrounds) 150 { 151 state = PTR_ALIGN(state, CHACHA_STATE_ALIGN); 152 153 if (!static_branch_likely(&chacha_use_simd) || !crypto_simd_usable() || 154 bytes <= CHACHA_BLOCK_SIZE) 155 return chacha_crypt_generic(state, dst, src, bytes, nrounds); 156 157 kernel_fpu_begin(); 158 chacha_dosimd(state, dst, src, bytes, nrounds); 159 kernel_fpu_end(); 160 } 161 EXPORT_SYMBOL(chacha_crypt_arch); 162 163 static int chacha_simd_stream_xor(struct skcipher_request *req, 164 const struct chacha_ctx *ctx, const u8 *iv) 165 { 166 u32 *state, state_buf[16 + 2] __aligned(8); 167 struct skcipher_walk walk; 168 int err; 169 170 err = skcipher_walk_virt(&walk, req, false); 171 172 BUILD_BUG_ON(CHACHA_STATE_ALIGN != 16); 173 state = PTR_ALIGN(state_buf + 0, CHACHA_STATE_ALIGN); 174 175 chacha_init_generic(state, ctx->key, iv); 176 177 while (walk.nbytes > 0) { 178 unsigned int nbytes = walk.nbytes; 179 180 if (nbytes < walk.total) 181 nbytes = round_down(nbytes, walk.stride); 182 183 if (!static_branch_likely(&chacha_use_simd) || 184 !crypto_simd_usable()) { 185 chacha_crypt_generic(state, walk.dst.virt.addr, 186 walk.src.virt.addr, nbytes, 187 ctx->nrounds); 188 } else { 189 kernel_fpu_begin(); 190 chacha_dosimd(state, walk.dst.virt.addr, 191 walk.src.virt.addr, nbytes, 192 ctx->nrounds); 193 kernel_fpu_end(); 194 } 195 err = skcipher_walk_done(&walk, walk.nbytes - nbytes); 196 } 197 198 return err; 199 } 200 201 static int chacha_simd(struct skcipher_request *req) 202 { 203 struct crypto_skcipher *tfm = crypto_skcipher_reqtfm(req); 204 struct chacha_ctx *ctx = crypto_skcipher_ctx(tfm); 205 206 return chacha_simd_stream_xor(req, ctx, req->iv); 207 } 208 209 static int xchacha_simd(struct skcipher_request *req) 210 { 211 struct crypto_skcipher *tfm = crypto_skcipher_reqtfm(req); 212 struct chacha_ctx *ctx = crypto_skcipher_ctx(tfm); 213 u32 *state, state_buf[16 + 2] __aligned(8); 214 struct chacha_ctx subctx; 215 u8 real_iv[16]; 216 217 BUILD_BUG_ON(CHACHA_STATE_ALIGN != 16); 218 state = PTR_ALIGN(state_buf + 0, CHACHA_STATE_ALIGN); 219 chacha_init_generic(state, ctx->key, req->iv); 220 221 if (req->cryptlen > CHACHA_BLOCK_SIZE && crypto_simd_usable()) { 222 kernel_fpu_begin(); 223 hchacha_block_ssse3(state, subctx.key, ctx->nrounds); 224 kernel_fpu_end(); 225 } else { 226 hchacha_block_generic(state, subctx.key, ctx->nrounds); 227 } 228 subctx.nrounds = ctx->nrounds; 229 230 memcpy(&real_iv[0], req->iv + 24, 8); 231 memcpy(&real_iv[8], req->iv + 16, 8); 232 return chacha_simd_stream_xor(req, &subctx, real_iv); 233 } 234 235 static struct skcipher_alg algs[] = { 236 { 237 .base.cra_name = "chacha20", 238 .base.cra_driver_name = "chacha20-simd", 239 .base.cra_priority = 300, 240 .base.cra_blocksize = 1, 241 .base.cra_ctxsize = sizeof(struct chacha_ctx), 242 .base.cra_module = THIS_MODULE, 243 244 .min_keysize = CHACHA_KEY_SIZE, 245 .max_keysize = CHACHA_KEY_SIZE, 246 .ivsize = CHACHA_IV_SIZE, 247 .chunksize = CHACHA_BLOCK_SIZE, 248 .setkey = chacha20_setkey, 249 .encrypt = chacha_simd, 250 .decrypt = chacha_simd, 251 }, { 252 .base.cra_name = "xchacha20", 253 .base.cra_driver_name = "xchacha20-simd", 254 .base.cra_priority = 300, 255 .base.cra_blocksize = 1, 256 .base.cra_ctxsize = sizeof(struct chacha_ctx), 257 .base.cra_module = THIS_MODULE, 258 259 .min_keysize = CHACHA_KEY_SIZE, 260 .max_keysize = CHACHA_KEY_SIZE, 261 .ivsize = XCHACHA_IV_SIZE, 262 .chunksize = CHACHA_BLOCK_SIZE, 263 .setkey = chacha20_setkey, 264 .encrypt = xchacha_simd, 265 .decrypt = xchacha_simd, 266 }, { 267 .base.cra_name = "xchacha12", 268 .base.cra_driver_name = "xchacha12-simd", 269 .base.cra_priority = 300, 270 .base.cra_blocksize = 1, 271 .base.cra_ctxsize = sizeof(struct chacha_ctx), 272 .base.cra_module = THIS_MODULE, 273 274 .min_keysize = CHACHA_KEY_SIZE, 275 .max_keysize = CHACHA_KEY_SIZE, 276 .ivsize = XCHACHA_IV_SIZE, 277 .chunksize = CHACHA_BLOCK_SIZE, 278 .setkey = chacha12_setkey, 279 .encrypt = xchacha_simd, 280 .decrypt = xchacha_simd, 281 }, 282 }; 283 284 static int __init chacha_simd_mod_init(void) 285 { 286 if (!boot_cpu_has(X86_FEATURE_SSSE3)) 287 return 0; 288 289 static_branch_enable(&chacha_use_simd); 290 291 if (IS_ENABLED(CONFIG_AS_AVX2) && 292 boot_cpu_has(X86_FEATURE_AVX) && 293 boot_cpu_has(X86_FEATURE_AVX2) && 294 cpu_has_xfeatures(XFEATURE_MASK_SSE | XFEATURE_MASK_YMM, NULL)) { 295 static_branch_enable(&chacha_use_avx2); 296 297 if (IS_ENABLED(CONFIG_AS_AVX512) && 298 boot_cpu_has(X86_FEATURE_AVX512VL) && 299 boot_cpu_has(X86_FEATURE_AVX512BW)) /* kmovq */ 300 static_branch_enable(&chacha_use_avx512vl); 301 } 302 return IS_REACHABLE(CONFIG_CRYPTO_SKCIPHER) ? 303 crypto_register_skciphers(algs, ARRAY_SIZE(algs)) : 0; 304 } 305 306 static void __exit chacha_simd_mod_fini(void) 307 { 308 if (IS_REACHABLE(CONFIG_CRYPTO_SKCIPHER) && boot_cpu_has(X86_FEATURE_SSSE3)) 309 crypto_unregister_skciphers(algs, ARRAY_SIZE(algs)); 310 } 311 312 module_init(chacha_simd_mod_init); 313 module_exit(chacha_simd_mod_fini); 314 315 MODULE_LICENSE("GPL"); 316 MODULE_AUTHOR("Martin Willi <martin@strongswan.org>"); 317 MODULE_DESCRIPTION("ChaCha and XChaCha stream ciphers (x64 SIMD accelerated)"); 318 MODULE_ALIAS_CRYPTO("chacha20"); 319 MODULE_ALIAS_CRYPTO("chacha20-simd"); 320 MODULE_ALIAS_CRYPTO("xchacha20"); 321 MODULE_ALIAS_CRYPTO("xchacha20-simd"); 322 MODULE_ALIAS_CRYPTO("xchacha12"); 323 MODULE_ALIAS_CRYPTO("xchacha12-simd"); 324