kernel/arch/arm/crypto/aes-ce-glue.c

   1 /*
   2  * aes-ce-glue.c - wrapper code for ARMv8 AES
   3  *
   4  * Copyright (C) 2015 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
  11 #include <asm/hwcap.h>
  12 #include <asm/neon.h>
  13 #include <asm/hwcap.h>
  14 #include <crypto/aes.h>
  15 #include <crypto/ablk_helper.h>
  16 #include <crypto/algapi.h>
  17 #include <linux/module.h>
  18
  19 MODULE_DESCRIPTION("AES-ECB/CBC/CTR/XTS using ARMv8 Crypto Extensions");
  20 MODULE_AUTHOR("Ard Biesheuvel <ard.biesheuvel@linaro.org>");
  21 MODULE_LICENSE("GPL v2");
  22
  23 /* defined in aes-ce-core.S */
  24 asmlinkage u32 ce_aes_sub(u32 input);
  25 asmlinkage void ce_aes_invert(void *dst, void *src);
  26
  27 asmlinkage void ce_aes_ecb_encrypt(u8 out[], u8 const in[], u8 const rk[],
  28                                    int rounds, int blocks);
  29 asmlinkage void ce_aes_ecb_decrypt(u8 out[], u8 const in[], u8 const rk[],
  30                                    int rounds, int blocks);
  31
  32 asmlinkage void ce_aes_cbc_encrypt(u8 out[], u8 const in[], u8 const rk[],
  33                                    int rounds, int blocks, u8 iv[]);
  34 asmlinkage void ce_aes_cbc_decrypt(u8 out[], u8 const in[], u8 const rk[],
  35                                    int rounds, int blocks, u8 iv[]);
  36
  37 asmlinkage void ce_aes_ctr_encrypt(u8 out[], u8 const in[], u8 const rk[],
  38                                    int rounds, int blocks, u8 ctr[]);
  39
  40 asmlinkage void ce_aes_xts_encrypt(u8 out[], u8 const in[], u8 const rk1[],
  41                                    int rounds, int blocks, u8 iv[],
  42                                    u8 const rk2[], int first);
  43 asmlinkage void ce_aes_xts_decrypt(u8 out[], u8 const in[], u8 const rk1[],
  44                                    int rounds, int blocks, u8 iv[],
  45                                    u8 const rk2[], int first);
  46
  47 struct aes_block {
  48         u8 b[AES_BLOCK_SIZE];
  49 };
  50
  51 static int num_rounds(struct crypto_aes_ctx *ctx)
  52 {
  53         /*
  54          * # of rounds specified by AES:
  55          * 128 bit key          10 rounds
  56          * 192 bit key          12 rounds
  57          * 256 bit key          14 rounds
  58          * => n byte key        => 6 + (n/4) rounds
  59          */
  60         return 6 + ctx->key_length / 4;
  61 }
  62
  63 static int ce_aes_expandkey(struct crypto_aes_ctx *ctx, const u8 *in_key,
  64                             unsigned int key_len)
  65 {
  66         /*
  67          * The AES key schedule round constants
  68          */
  69         static u8 const rcon[] = {
  70                 0x01, 0x02, 0x04, 0x08, 0x10, 0x20, 0x40, 0x80, 0x1b, 0x36,
  71         };
  72
  73         u32 kwords = key_len / sizeof(u32);
  74         struct aes_block *key_enc, *key_dec;
  75         int i, j;
  76
  77         if (key_len != AES_KEYSIZE_128 &&
  78             key_len != AES_KEYSIZE_192 &&
  79             key_len != AES_KEYSIZE_256)
  80                 return -EINVAL;
  81
  82         memcpy(ctx->key_enc, in_key, key_len);
  83         ctx->key_length = key_len;
  84
  85         kernel_neon_begin();
  86         for (i = 0; i < sizeof(rcon); i++) {
  87                 u32 *rki = ctx->key_enc + (i * kwords);
  88                 u32 *rko = rki + kwords;
  89
  90 #ifndef CONFIG_CPU_BIG_ENDIAN
  91                 rko[0] = ror32(ce_aes_sub(rki[kwords - 1]), 8);
  92                 rko[0] = rko[0] ^ rki[0] ^ rcon[i];
  93 #else
  94                 rko[0] = rol32(ce_aes_sub(rki[kwords - 1]), 8);
  95                 rko[0] = rko[0] ^ rki[0] ^ (rcon[i] << 24);
  96 #endif
  97                 rko[1] = rko[0] ^ rki[1];
  98                 rko[2] = rko[1] ^ rki[2];
  99                 rko[3] = rko[2] ^ rki[3];
 100
 101                 if (key_len == AES_KEYSIZE_192) {
 102                         if (i >= 7)
 103                                 break;
 104                         rko[4] = rko[3] ^ rki[4];
 105                         rko[5] = rko[4] ^ rki[5];
 106                 } else if (key_len == AES_KEYSIZE_256) {
 107                         if (i >= 6)
 108                                 break;
 109                         rko[4] = ce_aes_sub(rko[3]) ^ rki[4];
 110                         rko[5] = rko[4] ^ rki[5];
 111                         rko[6] = rko[5] ^ rki[6];
 112                         rko[7] = rko[6] ^ rki[7];
 113                 }
 114         }
 115
 116         /*
 117          * Generate the decryption keys for the Equivalent Inverse Cipher.
 118          * This involves reversing the order of the round keys, and applying
 119          * the Inverse Mix Columns transformation on all but the first and
 120          * the last one.
 121          */
 122         key_enc = (struct aes_block *)ctx->key_enc;
 123         key_dec = (struct aes_block *)ctx->key_dec;
 124         j = num_rounds(ctx);
 125
 126         key_dec[0] = key_enc[j];
 127         for (i = 1, j--; j > 0; i++, j--)
 128                 ce_aes_invert(key_dec + i, key_enc + j);
 129         key_dec[i] = key_enc[0];
 130
 131         kernel_neon_end();
 132         return 0;
 133 }
 134
 135 static int ce_aes_setkey(struct crypto_tfm *tfm, const u8 *in_key,
 136                          unsigned int key_len)
 137 {
 138         struct crypto_aes_ctx *ctx = crypto_tfm_ctx(tfm);
 139         int ret;
 140
 141         ret = ce_aes_expandkey(ctx, in_key, key_len);
 142         if (!ret)
 143                 return 0;
 144
 145         tfm->crt_flags |= CRYPTO_TFM_RES_BAD_KEY_LEN;
 146         return -EINVAL;
 147 }
 148
 149 struct crypto_aes_xts_ctx {
 150         struct crypto_aes_ctx key1;
 151         struct crypto_aes_ctx __aligned(8) key2;
 152 };
 153
 154 static int xts_set_key(struct crypto_tfm *tfm, const u8 *in_key,
 155                        unsigned int key_len)
 156 {
 157         struct crypto_aes_xts_ctx *ctx = crypto_tfm_ctx(tfm);
 158         int ret;
 159
 160         ret = ce_aes_expandkey(&ctx->key1, in_key, key_len / 2);
 161         if (!ret)
 162                 ret = ce_aes_expandkey(&ctx->key2, &in_key[key_len / 2],
 163                                        key_len / 2);
 164         if (!ret)
 165                 return 0;
 166
 167         tfm->crt_flags |= CRYPTO_TFM_RES_BAD_KEY_LEN;
 168         return -EINVAL;
 169 }
 170
 171 static int ecb_encrypt(struct blkcipher_desc *desc, struct scatterlist *dst,
 172                        struct scatterlist *src, unsigned int nbytes)
 173 {
 174         struct crypto_aes_ctx *ctx = crypto_blkcipher_ctx(desc->tfm);
 175         struct blkcipher_walk walk;
 176         unsigned int blocks;
 177         int err;
 178
 179         desc->flags &= ~CRYPTO_TFM_REQ_MAY_SLEEP;
 180         blkcipher_walk_init(&walk, dst, src, nbytes);
 181         err = blkcipher_walk_virt(desc, &walk);
 182
 183         kernel_neon_begin();
 184         while ((blocks = (walk.nbytes / AES_BLOCK_SIZE))) {
 185                 ce_aes_ecb_encrypt(walk.dst.virt.addr, walk.src.virt.addr,
 186                                    (u8 *)ctx->key_enc, num_rounds(ctx), blocks);
 187                 err = blkcipher_walk_done(desc, &walk,
 188                                           walk.nbytes % AES_BLOCK_SIZE);
 189         }
 190         kernel_neon_end();
 191         return err;
 192 }
 193
 194 static int ecb_decrypt(struct blkcipher_desc *desc, struct scatterlist *dst,
 195                        struct scatterlist *src, unsigned int nbytes)
 196 {
 197         struct crypto_aes_ctx *ctx = crypto_blkcipher_ctx(desc->tfm);
 198         struct blkcipher_walk walk;
 199         unsigned int blocks;
 200         int err;
 201
 202         desc->flags &= ~CRYPTO_TFM_REQ_MAY_SLEEP;
 203         blkcipher_walk_init(&walk, dst, src, nbytes);
 204         err = blkcipher_walk_virt(desc, &walk);
 205
 206         kernel_neon_begin();
 207         while ((blocks = (walk.nbytes / AES_BLOCK_SIZE))) {
 208                 ce_aes_ecb_decrypt(walk.dst.virt.addr, walk.src.virt.addr,
 209                                    (u8 *)ctx->key_dec, num_rounds(ctx), blocks);
 210                 err = blkcipher_walk_done(desc, &walk,
 211                                           walk.nbytes % AES_BLOCK_SIZE);
 212         }
 213         kernel_neon_end();
 214         return err;
 215 }
 216
 217 static int cbc_encrypt(struct blkcipher_desc *desc, struct scatterlist *dst,
 218                        struct scatterlist *src, unsigned int nbytes)
 219 {
 220         struct crypto_aes_ctx *ctx = crypto_blkcipher_ctx(desc->tfm);
 221         struct blkcipher_walk walk;
 222         unsigned int blocks;
 223         int err;
 224
 225         desc->flags &= ~CRYPTO_TFM_REQ_MAY_SLEEP;
 226         blkcipher_walk_init(&walk, dst, src, nbytes);
 227         err = blkcipher_walk_virt(desc, &walk);
 228
 229         kernel_neon_begin();
 230         while ((blocks = (walk.nbytes / AES_BLOCK_SIZE))) {
 231                 ce_aes_cbc_encrypt(walk.dst.virt.addr, walk.src.virt.addr,
 232                                    (u8 *)ctx->key_enc, num_rounds(ctx), blocks,
 233                                    walk.iv);
 234                 err = blkcipher_walk_done(desc, &walk,
 235                                           walk.nbytes % AES_BLOCK_SIZE);
 236         }
 237         kernel_neon_end();
 238         return err;
 239 }
 240
 241 static int cbc_decrypt(struct blkcipher_desc *desc, struct scatterlist *dst,
 242                        struct scatterlist *src, unsigned int nbytes)
 243 {
 244         struct crypto_aes_ctx *ctx = crypto_blkcipher_ctx(desc->tfm);
 245         struct blkcipher_walk walk;
 246         unsigned int blocks;
 247         int err;
 248
 249         desc->flags &= ~CRYPTO_TFM_REQ_MAY_SLEEP;
 250         blkcipher_walk_init(&walk, dst, src, nbytes);
 251         err = blkcipher_walk_virt(desc, &walk);
 252
 253         kernel_neon_begin();
 254         while ((blocks = (walk.nbytes / AES_BLOCK_SIZE))) {
 255                 ce_aes_cbc_decrypt(walk.dst.virt.addr, walk.src.virt.addr,
 256                                    (u8 *)ctx->key_dec, num_rounds(ctx), blocks,
 257                                    walk.iv);
 258                 err = blkcipher_walk_done(desc, &walk,
 259                                           walk.nbytes % AES_BLOCK_SIZE);
 260         }
 261         kernel_neon_end();
 262         return err;
 263 }
 264
 265 static int ctr_encrypt(struct blkcipher_desc *desc, struct scatterlist *dst,
 266                        struct scatterlist *src, unsigned int nbytes)
 267 {
 268         struct crypto_aes_ctx *ctx = crypto_blkcipher_ctx(desc->tfm);
 269         struct blkcipher_walk walk;
 270         int err, blocks;
 271
 272         desc->flags &= ~CRYPTO_TFM_REQ_MAY_SLEEP;
 273         blkcipher_walk_init(&walk, dst, src, nbytes);
 274         err = blkcipher_walk_virt_block(desc, &walk, AES_BLOCK_SIZE);
 275
 276         kernel_neon_begin();
 277         while ((blocks = (walk.nbytes / AES_BLOCK_SIZE))) {
 278                 ce_aes_ctr_encrypt(walk.dst.virt.addr, walk.src.virt.addr,
 279                                    (u8 *)ctx->key_enc, num_rounds(ctx), blocks,
 280                                    walk.iv);
 281                 nbytes -= blocks * AES_BLOCK_SIZE;
 282                 if (nbytes && nbytes == walk.nbytes % AES_BLOCK_SIZE)
 283                         break;
 284                 err = blkcipher_walk_done(desc, &walk,
 285                                           walk.nbytes % AES_BLOCK_SIZE);
 286         }
 287         if (walk.nbytes % AES_BLOCK_SIZE) {
 288                 u8 *tdst = walk.dst.virt.addr + blocks * AES_BLOCK_SIZE;
 289                 u8 *tsrc = walk.src.virt.addr + blocks * AES_BLOCK_SIZE;
 290                 u8 __aligned(8) tail[AES_BLOCK_SIZE];
 291
 292                 /*
 293                  * Minimum alignment is 8 bytes, so if nbytes is <= 8, we need
 294                  * to tell aes_ctr_encrypt() to only read half a block.
 295                  */
 296                 blocks = (nbytes <= 8) ? -1 : 1;
 297
 298                 ce_aes_ctr_encrypt(tail, tsrc, (u8 *)ctx->key_enc,
 299                                    num_rounds(ctx), blocks, walk.iv);
 300                 memcpy(tdst, tail, nbytes);
 301                 err = blkcipher_walk_done(desc, &walk, 0);
 302         }
 303         kernel_neon_end();
 304
 305         return err;
 306 }
 307
 308 static int xts_encrypt(struct blkcipher_desc *desc, struct scatterlist *dst,
 309                        struct scatterlist *src, unsigned int nbytes)
 310 {
 311         struct crypto_aes_xts_ctx *ctx = crypto_blkcipher_ctx(desc->tfm);
 312         int err, first, rounds = num_rounds(&ctx->key1);
 313         struct blkcipher_walk walk;
 314         unsigned int blocks;
 315
 316         desc->flags &= ~CRYPTO_TFM_REQ_MAY_SLEEP;
 317         blkcipher_walk_init(&walk, dst, src, nbytes);
 318         err = blkcipher_walk_virt(desc, &walk);
 319
 320         kernel_neon_begin();
 321         for (first = 1; (blocks = (walk.nbytes / AES_BLOCK_SIZE)); first = 0) {
 322                 ce_aes_xts_encrypt(walk.dst.virt.addr, walk.src.virt.addr,
 323                                    (u8 *)ctx->key1.key_enc, rounds, blocks,
 324                                    walk.iv, (u8 *)ctx->key2.key_enc, first);
 325                 err = blkcipher_walk_done(desc, &walk,
 326                                           walk.nbytes % AES_BLOCK_SIZE);
 327         }
 328         kernel_neon_end();
 329
 330         return err;
 331 }
 332
 333 static int xts_decrypt(struct blkcipher_desc *desc, struct scatterlist *dst,
 334                        struct scatterlist *src, unsigned int nbytes)
 335 {
 336         struct crypto_aes_xts_ctx *ctx = crypto_blkcipher_ctx(desc->tfm);
 337         int err, first, rounds = num_rounds(&ctx->key1);
 338         struct blkcipher_walk walk;
 339         unsigned int blocks;
 340
 341         desc->flags &= ~CRYPTO_TFM_REQ_MAY_SLEEP;
 342         blkcipher_walk_init(&walk, dst, src, nbytes);
 343         err = blkcipher_walk_virt(desc, &walk);
 344
 345         kernel_neon_begin();
 346         for (first = 1; (blocks = (walk.nbytes / AES_BLOCK_SIZE)); first = 0) {
 347                 ce_aes_xts_decrypt(walk.dst.virt.addr, walk.src.virt.addr,
 348                                    (u8 *)ctx->key1.key_dec, rounds, blocks,
 349                                    walk.iv, (u8 *)ctx->key2.key_enc, first);
 350                 err = blkcipher_walk_done(desc, &walk,
 351                                           walk.nbytes % AES_BLOCK_SIZE);
 352         }
 353         kernel_neon_end();
 354
 355         return err;
 356 }
 357
 358 static struct crypto_alg aes_algs[] = { {
 359         .cra_name               = "__ecb-aes-ce",
 360         .cra_driver_name        = "__driver-ecb-aes-ce",
 361         .cra_priority           = 0,
 362         .cra_flags              = CRYPTO_ALG_TYPE_BLKCIPHER |
 363                                   CRYPTO_ALG_INTERNAL,
 364         .cra_blocksize          = AES_BLOCK_SIZE,
 365         .cra_ctxsize            = sizeof(struct crypto_aes_ctx),
 366         .cra_alignmask          = 7,
 367         .cra_type               = &crypto_blkcipher_type,
 368         .cra_module             = THIS_MODULE,
 369         .cra_blkcipher = {
 370                 .min_keysize    = AES_MIN_KEY_SIZE,
 371                 .max_keysize    = AES_MAX_KEY_SIZE,
 372                 .ivsize         = AES_BLOCK_SIZE,
 373                 .setkey         = ce_aes_setkey,
 374                 .encrypt        = ecb_encrypt,
 375                 .decrypt        = ecb_decrypt,
 376         },
 377 }, {
 378         .cra_name               = "__cbc-aes-ce",
 379         .cra_driver_name        = "__driver-cbc-aes-ce",
 380         .cra_priority           = 0,
 381         .cra_flags              = CRYPTO_ALG_TYPE_BLKCIPHER |
 382                                   CRYPTO_ALG_INTERNAL,
 383         .cra_blocksize          = AES_BLOCK_SIZE,
 384         .cra_ctxsize            = sizeof(struct crypto_aes_ctx),
 385         .cra_alignmask          = 7,
 386         .cra_type               = &crypto_blkcipher_type,
 387         .cra_module             = THIS_MODULE,
 388         .cra_blkcipher = {
 389                 .min_keysize    = AES_MIN_KEY_SIZE,
 390                 .max_keysize    = AES_MAX_KEY_SIZE,
 391                 .ivsize         = AES_BLOCK_SIZE,
 392                 .setkey         = ce_aes_setkey,
 393                 .encrypt        = cbc_encrypt,
 394                 .decrypt        = cbc_decrypt,
 395         },
 396 }, {
 397         .cra_name               = "__ctr-aes-ce",
 398         .cra_driver_name        = "__driver-ctr-aes-ce",
 399         .cra_priority           = 0,
 400         .cra_flags              = CRYPTO_ALG_TYPE_BLKCIPHER |
 401                                   CRYPTO_ALG_INTERNAL,
 402         .cra_blocksize          = 1,
 403         .cra_ctxsize            = sizeof(struct crypto_aes_ctx),
 404         .cra_alignmask          = 7,
 405         .cra_type               = &crypto_blkcipher_type,
 406         .cra_module             = THIS_MODULE,
 407         .cra_blkcipher = {
 408                 .min_keysize    = AES_MIN_KEY_SIZE,
 409                 .max_keysize    = AES_MAX_KEY_SIZE,
 410                 .ivsize         = AES_BLOCK_SIZE,
 411                 .setkey         = ce_aes_setkey,
 412                 .encrypt        = ctr_encrypt,
 413                 .decrypt        = ctr_encrypt,
 414         },
 415 }, {
 416         .cra_name               = "__xts-aes-ce",
 417         .cra_driver_name        = "__driver-xts-aes-ce",
 418         .cra_priority           = 0,
 419         .cra_flags              = CRYPTO_ALG_TYPE_BLKCIPHER |
 420                                   CRYPTO_ALG_INTERNAL,
 421         .cra_blocksize          = AES_BLOCK_SIZE,
 422         .cra_ctxsize            = sizeof(struct crypto_aes_xts_ctx),
 423         .cra_alignmask          = 7,
 424         .cra_type               = &crypto_blkcipher_type,
 425         .cra_module             = THIS_MODULE,
 426         .cra_blkcipher = {
 427                 .min_keysize    = 2 * AES_MIN_KEY_SIZE,
 428                 .max_keysize    = 2 * AES_MAX_KEY_SIZE,
 429                 .ivsize         = AES_BLOCK_SIZE,
 430                 .setkey         = xts_set_key,
 431                 .encrypt        = xts_encrypt,
 432                 .decrypt        = xts_decrypt,
 433         },
 434 }, {
 435         .cra_name               = "ecb(aes)",
 436         .cra_driver_name        = "ecb-aes-ce",
 437         .cra_priority           = 300,
 438         .cra_flags              = CRYPTO_ALG_TYPE_ABLKCIPHER|CRYPTO_ALG_ASYNC,
 439         .cra_blocksize          = AES_BLOCK_SIZE,
 440         .cra_ctxsize            = sizeof(struct async_helper_ctx),
 441         .cra_alignmask          = 7,
 442         .cra_type               = &crypto_ablkcipher_type,
 443         .cra_module             = THIS_MODULE,
 444         .cra_init               = ablk_init,
 445         .cra_exit               = ablk_exit,
 446         .cra_ablkcipher = {
 447                 .min_keysize    = AES_MIN_KEY_SIZE,
 448                 .max_keysize    = AES_MAX_KEY_SIZE,
 449                 .ivsize         = AES_BLOCK_SIZE,
 450                 .setkey         = ablk_set_key,
 451                 .encrypt        = ablk_encrypt,
 452                 .decrypt        = ablk_decrypt,
 453         }
 454 }, {
 455         .cra_name               = "cbc(aes)",
 456         .cra_driver_name        = "cbc-aes-ce",
 457         .cra_priority           = 300,
 458         .cra_flags              = CRYPTO_ALG_TYPE_ABLKCIPHER|CRYPTO_ALG_ASYNC,
 459         .cra_blocksize          = AES_BLOCK_SIZE,
 460         .cra_ctxsize            = sizeof(struct async_helper_ctx),
 461         .cra_alignmask          = 7,
 462         .cra_type               = &crypto_ablkcipher_type,
 463         .cra_module             = THIS_MODULE,
 464         .cra_init               = ablk_init,
 465         .cra_exit               = ablk_exit,
 466         .cra_ablkcipher = {
 467                 .min_keysize    = AES_MIN_KEY_SIZE,
 468                 .max_keysize    = AES_MAX_KEY_SIZE,
 469                 .ivsize         = AES_BLOCK_SIZE,
 470                 .setkey         = ablk_set_key,
 471                 .encrypt        = ablk_encrypt,
 472                 .decrypt        = ablk_decrypt,
 473         }
 474 }, {
 475         .cra_name               = "ctr(aes)",
 476         .cra_driver_name        = "ctr-aes-ce",
 477         .cra_priority           = 300,
 478         .cra_flags              = CRYPTO_ALG_TYPE_ABLKCIPHER|CRYPTO_ALG_ASYNC,
 479         .cra_blocksize          = 1,
 480         .cra_ctxsize            = sizeof(struct async_helper_ctx),
 481         .cra_alignmask          = 7,
 482         .cra_type               = &crypto_ablkcipher_type,
 483         .cra_module             = THIS_MODULE,
 484         .cra_init               = ablk_init,
 485         .cra_exit               = ablk_exit,
 486         .cra_ablkcipher = {
 487                 .min_keysize    = AES_MIN_KEY_SIZE,
 488                 .max_keysize    = AES_MAX_KEY_SIZE,
 489                 .ivsize         = AES_BLOCK_SIZE,
 490                 .setkey         = ablk_set_key,
 491                 .encrypt        = ablk_encrypt,
 492                 .decrypt        = ablk_decrypt,
 493         }
 494 }, {
 495         .cra_name               = "xts(aes)",
 496         .cra_driver_name        = "xts-aes-ce",
 497         .cra_priority           = 300,
 498         .cra_flags              = CRYPTO_ALG_TYPE_ABLKCIPHER|CRYPTO_ALG_ASYNC,
 499         .cra_blocksize          = AES_BLOCK_SIZE,
 500         .cra_ctxsize            = sizeof(struct async_helper_ctx),
 501         .cra_alignmask          = 7,
 502         .cra_type               = &crypto_ablkcipher_type,
 503         .cra_module             = THIS_MODULE,
 504         .cra_init               = ablk_init,
 505         .cra_exit               = ablk_exit,
 506         .cra_ablkcipher = {
 507                 .min_keysize    = 2 * AES_MIN_KEY_SIZE,
 508                 .max_keysize    = 2 * AES_MAX_KEY_SIZE,
 509                 .ivsize         = AES_BLOCK_SIZE,
 510                 .setkey         = ablk_set_key,
 511                 .encrypt        = ablk_encrypt,
 512                 .decrypt        = ablk_decrypt,
 513         }
 514 } };
 515
 516 static int __init aes_init(void)
 517 {
 518         if (!(elf_hwcap2 & HWCAP2_AES))
 519                 return -ENODEV;
 520         return crypto_register_algs(aes_algs, ARRAY_SIZE(aes_algs));
 521 }
 522
 523 static void __exit aes_exit(void)
 524 {
 525         crypto_unregister_algs(aes_algs, ARRAY_SIZE(aes_algs));
 526 }
 527
 528 module_init(aes_init);
 529 module_exit(aes_exit);