arch/x86/crypto/chacha_glue.c

   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 <linux/sizes.h>
  16 #include <asm/simd.h>
  17
  18 asmlinkage void chacha_block_xor_ssse3(u32 *state, u8 *dst, const u8 *src,
  19                                        unsigned int len, int nrounds);
  20 asmlinkage void chacha_4block_xor_ssse3(u32 *state, u8 *dst, const u8 *src,
  21                                         unsigned int len, int nrounds);
  22 asmlinkage void hchacha_block_ssse3(const u32 *state, u32 *out, int nrounds);
  23
  24 asmlinkage void chacha_2block_xor_avx2(u32 *state, u8 *dst, const u8 *src,
  25                                        unsigned int len, int nrounds);
  26 asmlinkage void chacha_4block_xor_avx2(u32 *state, u8 *dst, const u8 *src,
  27                                        unsigned int len, int nrounds);
  28 asmlinkage void chacha_8block_xor_avx2(u32 *state, u8 *dst, const u8 *src,
  29                                        unsigned int len, int nrounds);
  30
  31 asmlinkage void chacha_2block_xor_avx512vl(u32 *state, u8 *dst, const u8 *src,
  32                                            unsigned int len, int nrounds);
  33 asmlinkage void chacha_4block_xor_avx512vl(u32 *state, u8 *dst, const u8 *src,
  34                                            unsigned int len, int nrounds);
  35 asmlinkage void chacha_8block_xor_avx512vl(u32 *state, u8 *dst, const u8 *src,
  36                                            unsigned int len, int nrounds);
  37
  38 static __ro_after_init DEFINE_STATIC_KEY_FALSE(chacha_use_simd);
  39 static __ro_after_init DEFINE_STATIC_KEY_FALSE(chacha_use_avx2);
  40 static __ro_after_init DEFINE_STATIC_KEY_FALSE(chacha_use_avx512vl);
  41
  42 static unsigned int chacha_advance(unsigned int len, unsigned int maxblocks)
  43 {
  44         len = min(len, maxblocks * CHACHA_BLOCK_SIZE);
  45         return round_up(len, CHACHA_BLOCK_SIZE) / CHACHA_BLOCK_SIZE;
  46 }
  47
  48 static void chacha_dosimd(u32 *state, u8 *dst, const u8 *src,
  49                           unsigned int bytes, int nrounds)
  50 {
  51         if (IS_ENABLED(CONFIG_AS_AVX512) &&
  52             static_branch_likely(&chacha_use_avx512vl)) {
  53                 while (bytes >= CHACHA_BLOCK_SIZE * 8) {
  54                         chacha_8block_xor_avx512vl(state, dst, src, bytes,
  55                                                    nrounds);
  56                         bytes -= CHACHA_BLOCK_SIZE * 8;
  57                         src += CHACHA_BLOCK_SIZE * 8;
  58                         dst += CHACHA_BLOCK_SIZE * 8;
  59                         state[12] += 8;
  60                 }
  61                 if (bytes > CHACHA_BLOCK_SIZE * 4) {
  62                         chacha_8block_xor_avx512vl(state, dst, src, bytes,
  63                                                    nrounds);
  64                         state[12] += chacha_advance(bytes, 8);
  65                         return;
  66                 }
  67                 if (bytes > CHACHA_BLOCK_SIZE * 2) {
  68                         chacha_4block_xor_avx512vl(state, dst, src, bytes,
  69                                                    nrounds);
  70                         state[12] += chacha_advance(bytes, 4);
  71                         return;
  72                 }
  73                 if (bytes) {
  74                         chacha_2block_xor_avx512vl(state, dst, src, bytes,
  75                                                    nrounds);
  76                         state[12] += chacha_advance(bytes, 2);
  77                         return;
  78                 }
  79         }
  80
  81         if (static_branch_likely(&chacha_use_avx2)) {
  82                 while (bytes >= CHACHA_BLOCK_SIZE * 8) {
  83                         chacha_8block_xor_avx2(state, dst, src, bytes, nrounds);
  84                         bytes -= CHACHA_BLOCK_SIZE * 8;
  85                         src += CHACHA_BLOCK_SIZE * 8;
  86                         dst += CHACHA_BLOCK_SIZE * 8;
  87                         state[12] += 8;
  88                 }
  89                 if (bytes > CHACHA_BLOCK_SIZE * 4) {
  90                         chacha_8block_xor_avx2(state, dst, src, bytes, nrounds);
  91                         state[12] += chacha_advance(bytes, 8);
  92                         return;
  93                 }
  94                 if (bytes > CHACHA_BLOCK_SIZE * 2) {
  95                         chacha_4block_xor_avx2(state, dst, src, bytes, nrounds);
  96                         state[12] += chacha_advance(bytes, 4);
  97                         return;
  98                 }
  99                 if (bytes > CHACHA_BLOCK_SIZE) {
 100                         chacha_2block_xor_avx2(state, dst, src, bytes, nrounds);
 101                         state[12] += chacha_advance(bytes, 2);
 102                         return;
 103                 }
 104         }
 105
 106         while (bytes >= CHACHA_BLOCK_SIZE * 4) {
 107                 chacha_4block_xor_ssse3(state, dst, src, bytes, nrounds);
 108                 bytes -= CHACHA_BLOCK_SIZE * 4;
 109                 src += CHACHA_BLOCK_SIZE * 4;
 110                 dst += CHACHA_BLOCK_SIZE * 4;
 111                 state[12] += 4;
 112         }
 113         if (bytes > CHACHA_BLOCK_SIZE) {
 114                 chacha_4block_xor_ssse3(state, dst, src, bytes, nrounds);
 115                 state[12] += chacha_advance(bytes, 4);
 116                 return;
 117         }
 118         if (bytes) {
 119                 chacha_block_xor_ssse3(state, dst, src, bytes, nrounds);
 120                 state[12]++;
 121         }
 122 }
 123
 124 void hchacha_block_arch(const u32 *state, u32 *stream, int nrounds)
 125 {
 126         if (!static_branch_likely(&chacha_use_simd) || !crypto_simd_usable()) {
 127                 hchacha_block_generic(state, stream, nrounds);
 128         } else {
 129                 kernel_fpu_begin();
 130                 hchacha_block_ssse3(state, stream, nrounds);
 131                 kernel_fpu_end();
 132         }
 133 }
 134 EXPORT_SYMBOL(hchacha_block_arch);
 135
 136 void chacha_init_arch(u32 *state, const u32 *key, const u8 *iv)
 137 {
 138         chacha_init_generic(state, key, iv);
 139 }
 140 EXPORT_SYMBOL(chacha_init_arch);
 141
 142 void chacha_crypt_arch(u32 *state, u8 *dst, const u8 *src, unsigned int bytes,
 143                        int nrounds)
 144 {
 145         if (!static_branch_likely(&chacha_use_simd) || !crypto_simd_usable() ||
 146             bytes <= CHACHA_BLOCK_SIZE)
 147                 return chacha_crypt_generic(state, dst, src, bytes, nrounds);
 148
 149         do {
 150                 unsigned int todo = min_t(unsigned int, bytes, SZ_4K);
 151
 152                 kernel_fpu_begin();
 153                 chacha_dosimd(state, dst, src, todo, nrounds);
 154                 kernel_fpu_end();
 155
 156                 bytes -= todo;
 157                 src += todo;
 158                 dst += todo;
 159         } while (bytes);
 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[CHACHA_STATE_WORDS] __aligned(8);
 167         struct skcipher_walk walk;
 168         int err;
 169
 170         err = skcipher_walk_virt(&walk, req, false);
 171
 172         chacha_init_generic(state, ctx->key, iv);
 173
 174         while (walk.nbytes > 0) {
 175                 unsigned int nbytes = walk.nbytes;
 176
 177                 if (nbytes < walk.total)
 178                         nbytes = round_down(nbytes, walk.stride);
 179
 180                 if (!static_branch_likely(&chacha_use_simd) ||
 181                     !crypto_simd_usable()) {
 182                         chacha_crypt_generic(state, walk.dst.virt.addr,
 183                                              walk.src.virt.addr, nbytes,
 184                                              ctx->nrounds);
 185                 } else {
 186                         kernel_fpu_begin();
 187                         chacha_dosimd(state, walk.dst.virt.addr,
 188                                       walk.src.virt.addr, nbytes,
 189                                       ctx->nrounds);
 190                         kernel_fpu_end();
 191                 }
 192                 err = skcipher_walk_done(&walk, walk.nbytes - nbytes);
 193         }
 194
 195         return err;
 196 }
 197
 198 static int chacha_simd(struct skcipher_request *req)
 199 {
 200         struct crypto_skcipher *tfm = crypto_skcipher_reqtfm(req);
 201         struct chacha_ctx *ctx = crypto_skcipher_ctx(tfm);
 202
 203         return chacha_simd_stream_xor(req, ctx, req->iv);
 204 }
 205
 206 static int xchacha_simd(struct skcipher_request *req)
 207 {
 208         struct crypto_skcipher *tfm = crypto_skcipher_reqtfm(req);
 209         struct chacha_ctx *ctx = crypto_skcipher_ctx(tfm);
 210         u32 state[CHACHA_STATE_WORDS] __aligned(8);
 211         struct chacha_ctx subctx;
 212         u8 real_iv[16];
 213
 214         chacha_init_generic(state, ctx->key, req->iv);
 215
 216         if (req->cryptlen > CHACHA_BLOCK_SIZE && crypto_simd_usable()) {
 217                 kernel_fpu_begin();
 218                 hchacha_block_ssse3(state, subctx.key, ctx->nrounds);
 219                 kernel_fpu_end();
 220         } else {
 221                 hchacha_block_generic(state, subctx.key, ctx->nrounds);
 222         }
 223         subctx.nrounds = ctx->nrounds;
 224
 225         memcpy(&real_iv[0], req->iv + 24, 8);
 226         memcpy(&real_iv[8], req->iv + 16, 8);
 227         return chacha_simd_stream_xor(req, &subctx, real_iv);
 228 }
 229
 230 static struct skcipher_alg algs[] = {
 231         {
 232                 .base.cra_name          = "chacha20",
 233                 .base.cra_driver_name   = "chacha20-simd",
 234                 .base.cra_priority      = 300,
 235                 .base.cra_blocksize     = 1,
 236                 .base.cra_ctxsize       = sizeof(struct chacha_ctx),
 237                 .base.cra_module        = THIS_MODULE,
 238
 239                 .min_keysize            = CHACHA_KEY_SIZE,
 240                 .max_keysize            = CHACHA_KEY_SIZE,
 241                 .ivsize                 = CHACHA_IV_SIZE,
 242                 .chunksize              = CHACHA_BLOCK_SIZE,
 243                 .setkey                 = chacha20_setkey,
 244                 .encrypt                = chacha_simd,
 245                 .decrypt                = chacha_simd,
 246         }, {
 247                 .base.cra_name          = "xchacha20",
 248                 .base.cra_driver_name   = "xchacha20-simd",
 249                 .base.cra_priority      = 300,
 250                 .base.cra_blocksize     = 1,
 251                 .base.cra_ctxsize       = sizeof(struct chacha_ctx),
 252                 .base.cra_module        = THIS_MODULE,
 253
 254                 .min_keysize            = CHACHA_KEY_SIZE,
 255                 .max_keysize            = CHACHA_KEY_SIZE,
 256                 .ivsize                 = XCHACHA_IV_SIZE,
 257                 .chunksize              = CHACHA_BLOCK_SIZE,
 258                 .setkey                 = chacha20_setkey,
 259                 .encrypt                = xchacha_simd,
 260                 .decrypt                = xchacha_simd,
 261         }, {
 262                 .base.cra_name          = "xchacha12",
 263                 .base.cra_driver_name   = "xchacha12-simd",
 264                 .base.cra_priority      = 300,
 265                 .base.cra_blocksize     = 1,
 266                 .base.cra_ctxsize       = sizeof(struct chacha_ctx),
 267                 .base.cra_module        = THIS_MODULE,
 268
 269                 .min_keysize            = CHACHA_KEY_SIZE,
 270                 .max_keysize            = CHACHA_KEY_SIZE,
 271                 .ivsize                 = XCHACHA_IV_SIZE,
 272                 .chunksize              = CHACHA_BLOCK_SIZE,
 273                 .setkey                 = chacha12_setkey,
 274                 .encrypt                = xchacha_simd,
 275                 .decrypt                = xchacha_simd,
 276         },
 277 };
 278
 279 static int __init chacha_simd_mod_init(void)
 280 {
 281         if (!boot_cpu_has(X86_FEATURE_SSSE3))
 282                 return 0;
 283
 284         static_branch_enable(&chacha_use_simd);
 285
 286         if (boot_cpu_has(X86_FEATURE_AVX) &&
 287             boot_cpu_has(X86_FEATURE_AVX2) &&
 288             cpu_has_xfeatures(XFEATURE_MASK_SSE | XFEATURE_MASK_YMM, NULL)) {
 289                 static_branch_enable(&chacha_use_avx2);
 290
 291                 if (IS_ENABLED(CONFIG_AS_AVX512) &&
 292                     boot_cpu_has(X86_FEATURE_AVX512VL) &&
 293                     boot_cpu_has(X86_FEATURE_AVX512BW)) /* kmovq */
 294                         static_branch_enable(&chacha_use_avx512vl);
 295         }
 296         return IS_REACHABLE(CONFIG_CRYPTO_SKCIPHER) ?
 297                 crypto_register_skciphers(algs, ARRAY_SIZE(algs)) : 0;
 298 }
 299
 300 static void __exit chacha_simd_mod_fini(void)
 301 {
 302         if (IS_REACHABLE(CONFIG_CRYPTO_SKCIPHER) && boot_cpu_has(X86_FEATURE_SSSE3))
 303                 crypto_unregister_skciphers(algs, ARRAY_SIZE(algs));
 304 }
 305
 306 module_init(chacha_simd_mod_init);
 307 module_exit(chacha_simd_mod_fini);
 308
 309 MODULE_LICENSE("GPL");
 310 MODULE_AUTHOR("Martin Willi <martin@strongswan.org>");
 311 MODULE_DESCRIPTION("ChaCha and XChaCha stream ciphers (x64 SIMD accelerated)");
 312 MODULE_ALIAS_CRYPTO("chacha20");
 313 MODULE_ALIAS_CRYPTO("chacha20-simd");
 314 MODULE_ALIAS_CRYPTO("xchacha20");
 315 MODULE_ALIAS_CRYPTO("xchacha20-simd");
 316 MODULE_ALIAS_CRYPTO("xchacha12");
 317 MODULE_ALIAS_CRYPTO("xchacha12-simd");