drivers/crypto/geode-aes.c

   1  /* Copyright (C) 2004-2006, Advanced Micro Devices, Inc.
   2   *
   3   * This program is free software; you can redistribute it and/or modify
   4   * it under the terms of the GNU General Public License as published by
   5   * the Free Software Foundation; either version 2 of the License, or
   6   * (at your option) any later version.
   7   */
   8
   9 #include <linux/module.h>
  10 #include <linux/kernel.h>
  11 #include <linux/pci.h>
  12 #include <linux/pci_ids.h>
  13 #include <linux/crypto.h>
  14 #include <linux/spinlock.h>
  15 #include <crypto/algapi.h>
  16 #include <crypto/aes.h>
  17 #include <crypto/internal/skcipher.h>
  18
  19 #include <linux/io.h>
  20 #include <linux/delay.h>
  21
  22 #include "geode-aes.h"
  23
  24 /* Static structures */
  25
  26 static void __iomem *_iobase;
  27 static spinlock_t lock;
  28
  29 /* Write a 128 bit field (either a writable key or IV) */
  30 static inline void
  31 _writefield(u32 offset, const void *value)
  32 {
  33         int i;
  34
  35         for (i = 0; i < 4; i++)
  36                 iowrite32(((const u32 *) value)[i], _iobase + offset + (i * 4));
  37 }
  38
  39 /* Read a 128 bit field (either a writable key or IV) */
  40 static inline void
  41 _readfield(u32 offset, void *value)
  42 {
  43         int i;
  44
  45         for (i = 0; i < 4; i++)
  46                 ((u32 *) value)[i] = ioread32(_iobase + offset + (i * 4));
  47 }
  48
  49 static int
  50 do_crypt(const void *src, void *dst, u32 len, u32 flags)
  51 {
  52         u32 status;
  53         u32 counter = AES_OP_TIMEOUT;
  54
  55         iowrite32(virt_to_phys((void *)src), _iobase + AES_SOURCEA_REG);
  56         iowrite32(virt_to_phys(dst), _iobase + AES_DSTA_REG);
  57         iowrite32(len,  _iobase + AES_LENA_REG);
  58
  59         /* Start the operation */
  60         iowrite32(AES_CTRL_START | flags, _iobase + AES_CTRLA_REG);
  61
  62         do {
  63                 status = ioread32(_iobase + AES_INTR_REG);
  64                 cpu_relax();
  65         } while (!(status & AES_INTRA_PENDING) && --counter);
  66
  67         /* Clear the event */
  68         iowrite32((status & 0xFF) | AES_INTRA_PENDING, _iobase + AES_INTR_REG);
  69         return counter ? 0 : 1;
  70 }
  71
  72 static void
  73 geode_aes_crypt(const struct geode_aes_tfm_ctx *tctx, const void *src,
  74                 void *dst, u32 len, u8 *iv, int mode, int dir)
  75 {
  76         u32 flags = 0;
  77         unsigned long iflags;
  78         int ret;
  79
  80         /* If the source and destination is the same, then
  81          * we need to turn on the coherent flags, otherwise
  82          * we don't need to worry
  83          */
  84
  85         flags |= (AES_CTRL_DCA | AES_CTRL_SCA);
  86
  87         if (dir == AES_DIR_ENCRYPT)
  88                 flags |= AES_CTRL_ENCRYPT;
  89
  90         /* Start the critical section */
  91
  92         spin_lock_irqsave(&lock, iflags);
  93
  94         if (mode == AES_MODE_CBC) {
  95                 flags |= AES_CTRL_CBC;
  96                 _writefield(AES_WRITEIV0_REG, iv);
  97         }
  98
  99         flags |= AES_CTRL_WRKEY;
 100         _writefield(AES_WRITEKEY0_REG, tctx->key);
 101
 102         ret = do_crypt(src, dst, len, flags);
 103         BUG_ON(ret);
 104
 105         if (mode == AES_MODE_CBC)
 106                 _readfield(AES_WRITEIV0_REG, iv);
 107
 108         spin_unlock_irqrestore(&lock, iflags);
 109 }
 110
 111 /* CRYPTO-API Functions */
 112
 113 static int geode_setkey_cip(struct crypto_tfm *tfm, const u8 *key,
 114                 unsigned int len)
 115 {
 116         struct geode_aes_tfm_ctx *tctx = crypto_tfm_ctx(tfm);
 117         unsigned int ret;
 118
 119         tctx->keylen = len;
 120
 121         if (len == AES_KEYSIZE_128) {
 122                 memcpy(tctx->key, key, len);
 123                 return 0;
 124         }
 125
 126         if (len != AES_KEYSIZE_192 && len != AES_KEYSIZE_256) {
 127                 /* not supported at all */
 128                 tfm->crt_flags |= CRYPTO_TFM_RES_BAD_KEY_LEN;
 129                 return -EINVAL;
 130         }
 131
 132         /*
 133          * The requested key size is not supported by HW, do a fallback
 134          */
 135         tctx->fallback.cip->base.crt_flags &= ~CRYPTO_TFM_REQ_MASK;
 136         tctx->fallback.cip->base.crt_flags |=
 137                 (tfm->crt_flags & CRYPTO_TFM_REQ_MASK);
 138
 139         ret = crypto_cipher_setkey(tctx->fallback.cip, key, len);
 140         if (ret) {
 141                 tfm->crt_flags &= ~CRYPTO_TFM_RES_MASK;
 142                 tfm->crt_flags |= (tctx->fallback.cip->base.crt_flags &
 143                                    CRYPTO_TFM_RES_MASK);
 144         }
 145         return ret;
 146 }
 147
 148 static int geode_setkey_skcipher(struct crypto_skcipher *tfm, const u8 *key,
 149                                  unsigned int len)
 150 {
 151         struct geode_aes_tfm_ctx *tctx = crypto_skcipher_ctx(tfm);
 152         unsigned int ret;
 153
 154         tctx->keylen = len;
 155
 156         if (len == AES_KEYSIZE_128) {
 157                 memcpy(tctx->key, key, len);
 158                 return 0;
 159         }
 160
 161         if (len != AES_KEYSIZE_192 && len != AES_KEYSIZE_256) {
 162                 /* not supported at all */
 163                 crypto_skcipher_set_flags(tfm, CRYPTO_TFM_RES_BAD_KEY_LEN);
 164                 return -EINVAL;
 165         }
 166
 167         /*
 168          * The requested key size is not supported by HW, do a fallback
 169          */
 170         crypto_skcipher_clear_flags(tctx->fallback.skcipher,
 171                                     CRYPTO_TFM_REQ_MASK);
 172         crypto_skcipher_set_flags(tctx->fallback.skcipher,
 173                                   crypto_skcipher_get_flags(tfm) &
 174                                   CRYPTO_TFM_REQ_MASK);
 175         ret = crypto_skcipher_setkey(tctx->fallback.skcipher, key, len);
 176         crypto_skcipher_set_flags(tfm,
 177                                   crypto_skcipher_get_flags(tctx->fallback.skcipher) &
 178                                   CRYPTO_TFM_RES_MASK);
 179         return ret;
 180 }
 181
 182 static void
 183 geode_encrypt(struct crypto_tfm *tfm, u8 *out, const u8 *in)
 184 {
 185         const struct geode_aes_tfm_ctx *tctx = crypto_tfm_ctx(tfm);
 186
 187         if (unlikely(tctx->keylen != AES_KEYSIZE_128)) {
 188                 crypto_cipher_encrypt_one(tctx->fallback.cip, out, in);
 189                 return;
 190         }
 191
 192         geode_aes_crypt(tctx, in, out, AES_BLOCK_SIZE, NULL,
 193                         AES_MODE_ECB, AES_DIR_ENCRYPT);
 194 }
 195
 196
 197 static void
 198 geode_decrypt(struct crypto_tfm *tfm, u8 *out, const u8 *in)
 199 {
 200         const struct geode_aes_tfm_ctx *tctx = crypto_tfm_ctx(tfm);
 201
 202         if (unlikely(tctx->keylen != AES_KEYSIZE_128)) {
 203                 crypto_cipher_decrypt_one(tctx->fallback.cip, out, in);
 204                 return;
 205         }
 206
 207         geode_aes_crypt(tctx, in, out, AES_BLOCK_SIZE, NULL,
 208                         AES_MODE_ECB, AES_DIR_DECRYPT);
 209 }
 210
 211 static int fallback_init_cip(struct crypto_tfm *tfm)
 212 {
 213         const char *name = crypto_tfm_alg_name(tfm);
 214         struct geode_aes_tfm_ctx *tctx = crypto_tfm_ctx(tfm);
 215
 216         tctx->fallback.cip = crypto_alloc_cipher(name, 0,
 217                                                  CRYPTO_ALG_NEED_FALLBACK);
 218
 219         if (IS_ERR(tctx->fallback.cip)) {
 220                 printk(KERN_ERR "Error allocating fallback algo %s\n", name);
 221                 return PTR_ERR(tctx->fallback.cip);
 222         }
 223
 224         return 0;
 225 }
 226
 227 static void fallback_exit_cip(struct crypto_tfm *tfm)
 228 {
 229         struct geode_aes_tfm_ctx *tctx = crypto_tfm_ctx(tfm);
 230
 231         crypto_free_cipher(tctx->fallback.cip);
 232 }
 233
 234 static struct crypto_alg geode_alg = {
 235         .cra_name                       =       "aes",
 236         .cra_driver_name        =       "geode-aes",
 237         .cra_priority           =       300,
 238         .cra_alignmask          =       15,
 239         .cra_flags                      =       CRYPTO_ALG_TYPE_CIPHER |
 240                                                         CRYPTO_ALG_NEED_FALLBACK,
 241         .cra_init                       =       fallback_init_cip,
 242         .cra_exit                       =       fallback_exit_cip,
 243         .cra_blocksize          =       AES_BLOCK_SIZE,
 244         .cra_ctxsize            =       sizeof(struct geode_aes_tfm_ctx),
 245         .cra_module                     =       THIS_MODULE,
 246         .cra_u                          =       {
 247                 .cipher =       {
 248                         .cia_min_keysize        =       AES_MIN_KEY_SIZE,
 249                         .cia_max_keysize        =       AES_MAX_KEY_SIZE,
 250                         .cia_setkey                     =       geode_setkey_cip,
 251                         .cia_encrypt            =       geode_encrypt,
 252                         .cia_decrypt            =       geode_decrypt
 253                 }
 254         }
 255 };
 256
 257 static int geode_init_skcipher(struct crypto_skcipher *tfm)
 258 {
 259         const char *name = crypto_tfm_alg_name(&tfm->base);
 260         struct geode_aes_tfm_ctx *tctx = crypto_skcipher_ctx(tfm);
 261
 262         tctx->fallback.skcipher =
 263                 crypto_alloc_skcipher(name, 0, CRYPTO_ALG_NEED_FALLBACK |
 264                                       CRYPTO_ALG_ASYNC);
 265         if (IS_ERR(tctx->fallback.skcipher)) {
 266                 printk(KERN_ERR "Error allocating fallback algo %s\n", name);
 267                 return PTR_ERR(tctx->fallback.skcipher);
 268         }
 269
 270         crypto_skcipher_set_reqsize(tfm, sizeof(struct skcipher_request) +
 271                                     crypto_skcipher_reqsize(tctx->fallback.skcipher));
 272         return 0;
 273 }
 274
 275 static void geode_exit_skcipher(struct crypto_skcipher *tfm)
 276 {
 277         struct geode_aes_tfm_ctx *tctx = crypto_skcipher_ctx(tfm);
 278
 279         crypto_free_skcipher(tctx->fallback.skcipher);
 280 }
 281
 282 static int geode_skcipher_crypt(struct skcipher_request *req, int mode, int dir)
 283 {
 284         struct crypto_skcipher *tfm = crypto_skcipher_reqtfm(req);
 285         const struct geode_aes_tfm_ctx *tctx = crypto_skcipher_ctx(tfm);
 286         struct skcipher_walk walk;
 287         unsigned int nbytes;
 288         int err;
 289
 290         if (unlikely(tctx->keylen != AES_KEYSIZE_128)) {
 291                 struct skcipher_request *subreq = skcipher_request_ctx(req);
 292
 293                 *subreq = *req;
 294                 skcipher_request_set_tfm(subreq, tctx->fallback.skcipher);
 295                 if (dir == AES_DIR_DECRYPT)
 296                         return crypto_skcipher_decrypt(subreq);
 297                 else
 298                         return crypto_skcipher_encrypt(subreq);
 299         }
 300
 301         err = skcipher_walk_virt(&walk, req, false);
 302
 303         while ((nbytes = walk.nbytes) != 0) {
 304                 geode_aes_crypt(tctx, walk.src.virt.addr, walk.dst.virt.addr,
 305                                 round_down(nbytes, AES_BLOCK_SIZE),
 306                                 walk.iv, mode, dir);
 307                 err = skcipher_walk_done(&walk, nbytes % AES_BLOCK_SIZE);
 308         }
 309
 310         return err;
 311 }
 312
 313 static int geode_cbc_encrypt(struct skcipher_request *req)
 314 {
 315         return geode_skcipher_crypt(req, AES_MODE_CBC, AES_DIR_ENCRYPT);
 316 }
 317
 318 static int geode_cbc_decrypt(struct skcipher_request *req)
 319 {
 320         return geode_skcipher_crypt(req, AES_MODE_CBC, AES_DIR_DECRYPT);
 321 }
 322
 323 static int geode_ecb_encrypt(struct skcipher_request *req)
 324 {
 325         return geode_skcipher_crypt(req, AES_MODE_ECB, AES_DIR_ENCRYPT);
 326 }
 327
 328 static int geode_ecb_decrypt(struct skcipher_request *req)
 329 {
 330         return geode_skcipher_crypt(req, AES_MODE_ECB, AES_DIR_DECRYPT);
 331 }
 332
 333 static struct skcipher_alg geode_skcipher_algs[] = {
 334         {
 335                 .base.cra_name          = "cbc(aes)",
 336                 .base.cra_driver_name   = "cbc-aes-geode",
 337                 .base.cra_priority      = 400,
 338                 .base.cra_flags         = CRYPTO_ALG_KERN_DRIVER_ONLY |
 339                                           CRYPTO_ALG_NEED_FALLBACK,
 340                 .base.cra_blocksize     = AES_BLOCK_SIZE,
 341                 .base.cra_ctxsize       = sizeof(struct geode_aes_tfm_ctx),
 342                 .base.cra_alignmask     = 15,
 343                 .base.cra_module        = THIS_MODULE,
 344                 .init                   = geode_init_skcipher,
 345                 .exit                   = geode_exit_skcipher,
 346                 .setkey                 = geode_setkey_skcipher,
 347                 .encrypt                = geode_cbc_encrypt,
 348                 .decrypt                = geode_cbc_decrypt,
 349                 .min_keysize            = AES_MIN_KEY_SIZE,
 350                 .max_keysize            = AES_MAX_KEY_SIZE,
 351                 .ivsize                 = AES_BLOCK_SIZE,
 352         }, {
 353                 .base.cra_name          = "ecb(aes)",
 354                 .base.cra_driver_name   = "ecb-aes-geode",
 355                 .base.cra_priority      = 400,
 356                 .base.cra_flags         = CRYPTO_ALG_KERN_DRIVER_ONLY |
 357                                           CRYPTO_ALG_NEED_FALLBACK,
 358                 .base.cra_blocksize     = AES_BLOCK_SIZE,
 359                 .base.cra_ctxsize       = sizeof(struct geode_aes_tfm_ctx),
 360                 .base.cra_alignmask     = 15,
 361                 .base.cra_module        = THIS_MODULE,
 362                 .init                   = geode_init_skcipher,
 363                 .exit                   = geode_exit_skcipher,
 364                 .setkey                 = geode_setkey_skcipher,
 365                 .encrypt                = geode_ecb_encrypt,
 366                 .decrypt                = geode_ecb_decrypt,
 367                 .min_keysize            = AES_MIN_KEY_SIZE,
 368                 .max_keysize            = AES_MAX_KEY_SIZE,
 369         },
 370 };
 371
 372 static void geode_aes_remove(struct pci_dev *dev)
 373 {
 374         crypto_unregister_alg(&geode_alg);
 375         crypto_unregister_skciphers(geode_skcipher_algs,
 376                                     ARRAY_SIZE(geode_skcipher_algs));
 377
 378         pci_iounmap(dev, _iobase);
 379         _iobase = NULL;
 380
 381         pci_release_regions(dev);
 382         pci_disable_device(dev);
 383 }
 384
 385
 386 static int geode_aes_probe(struct pci_dev *dev, const struct pci_device_id *id)
 387 {
 388         int ret;
 389
 390         ret = pci_enable_device(dev);
 391         if (ret)
 392                 return ret;
 393
 394         ret = pci_request_regions(dev, "geode-aes");
 395         if (ret)
 396                 goto eenable;
 397
 398         _iobase = pci_iomap(dev, 0, 0);
 399
 400         if (_iobase == NULL) {
 401                 ret = -ENOMEM;
 402                 goto erequest;
 403         }
 404
 405         spin_lock_init(&lock);
 406
 407         /* Clear any pending activity */
 408         iowrite32(AES_INTR_PENDING | AES_INTR_MASK, _iobase + AES_INTR_REG);
 409
 410         ret = crypto_register_alg(&geode_alg);
 411         if (ret)
 412                 goto eiomap;
 413
 414         ret = crypto_register_skciphers(geode_skcipher_algs,
 415                                         ARRAY_SIZE(geode_skcipher_algs));
 416         if (ret)
 417                 goto ealg;
 418
 419         dev_notice(&dev->dev, "GEODE AES engine enabled.\n");
 420         return 0;
 421
 422  ealg:
 423         crypto_unregister_alg(&geode_alg);
 424
 425  eiomap:
 426         pci_iounmap(dev, _iobase);
 427
 428  erequest:
 429         pci_release_regions(dev);
 430
 431  eenable:
 432         pci_disable_device(dev);
 433
 434         dev_err(&dev->dev, "GEODE AES initialization failed.\n");
 435         return ret;
 436 }
 437
 438 static struct pci_device_id geode_aes_tbl[] = {
 439         { PCI_VDEVICE(AMD, PCI_DEVICE_ID_AMD_LX_AES), },
 440         { 0, }
 441 };
 442
 443 MODULE_DEVICE_TABLE(pci, geode_aes_tbl);
 444
 445 static struct pci_driver geode_aes_driver = {
 446         .name = "Geode LX AES",
 447         .id_table = geode_aes_tbl,
 448         .probe = geode_aes_probe,
 449         .remove = geode_aes_remove,
 450 };
 451
 452 module_pci_driver(geode_aes_driver);
 453
 454 MODULE_AUTHOR("Advanced Micro Devices, Inc.");
 455 MODULE_DESCRIPTION("Geode LX Hardware AES driver");
 456 MODULE_LICENSE("GPL");