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
  18 #include <linux/io.h>
  19 #include <linux/delay.h>
  20
  21 #include "geode-aes.h"
  22
  23 /* Static structures */
  24
  25 static void __iomem *_iobase;
  26 static spinlock_t lock;
  27
  28 /* Write a 128 bit field (either a writable key or IV) */
  29 static inline void
  30 _writefield(u32 offset, void *value)
  31 {
  32         int i;
  33         for (i = 0; i < 4; i++)
  34                 iowrite32(((u32 *) value)[i], _iobase + offset + (i * 4));
  35 }
  36
  37 /* Read a 128 bit field (either a writable key or IV) */
  38 static inline void
  39 _readfield(u32 offset, void *value)
  40 {
  41         int i;
  42         for (i = 0; i < 4; i++)
  43                 ((u32 *) value)[i] = ioread32(_iobase + offset + (i * 4));
  44 }
  45
  46 static int
  47 do_crypt(void *src, void *dst, int len, u32 flags)
  48 {
  49         u32 status;
  50         u32 counter = AES_OP_TIMEOUT;
  51
  52         iowrite32(virt_to_phys(src), _iobase + AES_SOURCEA_REG);
  53         iowrite32(virt_to_phys(dst), _iobase + AES_DSTA_REG);
  54         iowrite32(len,  _iobase + AES_LENA_REG);
  55
  56         /* Start the operation */
  57         iowrite32(AES_CTRL_START | flags, _iobase + AES_CTRLA_REG);
  58
  59         do {
  60                 status = ioread32(_iobase + AES_INTR_REG);
  61                 cpu_relax();
  62         } while (!(status & AES_INTRA_PENDING) && --counter);
  63
  64         /* Clear the event */
  65         iowrite32((status & 0xFF) | AES_INTRA_PENDING, _iobase + AES_INTR_REG);
  66         return counter ? 0 : 1;
  67 }
  68
  69 static unsigned int
  70 geode_aes_crypt(struct geode_aes_op *op)
  71 {
  72         u32 flags = 0;
  73         unsigned long iflags;
  74         int ret;
  75
  76         if (op->len == 0)
  77                 return 0;
  78
  79         /* If the source and destination is the same, then
  80          * we need to turn on the coherent flags, otherwise
  81          * we don't need to worry
  82          */
  83
  84         flags |= (AES_CTRL_DCA | AES_CTRL_SCA);
  85
  86         if (op->dir == AES_DIR_ENCRYPT)
  87                 flags |= AES_CTRL_ENCRYPT;
  88
  89         /* Start the critical section */
  90
  91         spin_lock_irqsave(&lock, iflags);
  92
  93         if (op->mode == AES_MODE_CBC) {
  94                 flags |= AES_CTRL_CBC;
  95                 _writefield(AES_WRITEIV0_REG, op->iv);
  96         }
  97
  98         if (!(op->flags & AES_FLAGS_HIDDENKEY)) {
  99                 flags |= AES_CTRL_WRKEY;
 100                 _writefield(AES_WRITEKEY0_REG, op->key);
 101         }
 102
 103         ret = do_crypt(op->src, op->dst, op->len, flags);
 104         BUG_ON(ret);
 105
 106         if (op->mode == AES_MODE_CBC)
 107                 _readfield(AES_WRITEIV0_REG, op->iv);
 108
 109         spin_unlock_irqrestore(&lock, iflags);
 110
 111         return op->len;
 112 }
 113
 114 /* CRYPTO-API Functions */
 115
 116 static int geode_setkey_cip(struct crypto_tfm *tfm, const u8 *key,
 117                 unsigned int len)
 118 {
 119         struct geode_aes_op *op = crypto_tfm_ctx(tfm);
 120         unsigned int ret;
 121
 122         op->keylen = len;
 123
 124         if (len == AES_KEYSIZE_128) {
 125                 memcpy(op->key, key, len);
 126                 return 0;
 127         }
 128
 129         if (len != AES_KEYSIZE_192 && len != AES_KEYSIZE_256) {
 130                 /* not supported at all */
 131                 tfm->crt_flags |= CRYPTO_TFM_RES_BAD_KEY_LEN;
 132                 return -EINVAL;
 133         }
 134
 135         /*
 136          * The requested key size is not supported by HW, do a fallback
 137          */
 138         op->fallback.cip->base.crt_flags &= ~CRYPTO_TFM_REQ_MASK;
 139         op->fallback.cip->base.crt_flags |= (tfm->crt_flags & CRYPTO_TFM_REQ_MASK);
 140
 141         ret = crypto_cipher_setkey(op->fallback.cip, key, len);
 142         if (ret) {
 143                 tfm->crt_flags &= ~CRYPTO_TFM_RES_MASK;
 144                 tfm->crt_flags |= (op->fallback.cip->base.crt_flags & CRYPTO_TFM_RES_MASK);
 145         }
 146         return ret;
 147 }
 148
 149 static int geode_setkey_blk(struct crypto_tfm *tfm, const u8 *key,
 150                 unsigned int len)
 151 {
 152         struct geode_aes_op *op = crypto_tfm_ctx(tfm);
 153         unsigned int ret;
 154
 155         op->keylen = len;
 156
 157         if (len == AES_KEYSIZE_128) {
 158                 memcpy(op->key, key, len);
 159                 return 0;
 160         }
 161
 162         if (len != AES_KEYSIZE_192 && len != AES_KEYSIZE_256) {
 163                 /* not supported at all */
 164                 tfm->crt_flags |= CRYPTO_TFM_RES_BAD_KEY_LEN;
 165                 return -EINVAL;
 166         }
 167
 168         /*
 169          * The requested key size is not supported by HW, do a fallback
 170          */
 171         op->fallback.blk->base.crt_flags &= ~CRYPTO_TFM_REQ_MASK;
 172         op->fallback.blk->base.crt_flags |= (tfm->crt_flags & CRYPTO_TFM_REQ_MASK);
 173
 174         ret = crypto_blkcipher_setkey(op->fallback.blk, key, len);
 175         if (ret) {
 176                 tfm->crt_flags &= ~CRYPTO_TFM_RES_MASK;
 177                 tfm->crt_flags |= (op->fallback.blk->base.crt_flags & CRYPTO_TFM_RES_MASK);
 178         }
 179         return ret;
 180 }
 181
 182 static int fallback_blk_dec(struct blkcipher_desc *desc,
 183                 struct scatterlist *dst, struct scatterlist *src,
 184                 unsigned int nbytes)
 185 {
 186         unsigned int ret;
 187         struct crypto_blkcipher *tfm;
 188         struct geode_aes_op *op = crypto_blkcipher_ctx(desc->tfm);
 189
 190         tfm = desc->tfm;
 191         desc->tfm = op->fallback.blk;
 192
 193         ret = crypto_blkcipher_decrypt_iv(desc, dst, src, nbytes);
 194
 195         desc->tfm = tfm;
 196         return ret;
 197 }
 198 static int fallback_blk_enc(struct blkcipher_desc *desc,
 199                 struct scatterlist *dst, struct scatterlist *src,
 200                 unsigned int nbytes)
 201 {
 202         unsigned int ret;
 203         struct crypto_blkcipher *tfm;
 204         struct geode_aes_op *op = crypto_blkcipher_ctx(desc->tfm);
 205
 206         tfm = desc->tfm;
 207         desc->tfm = op->fallback.blk;
 208
 209         ret = crypto_blkcipher_encrypt_iv(desc, dst, src, nbytes);
 210
 211         desc->tfm = tfm;
 212         return ret;
 213 }
 214
 215 static void
 216 geode_encrypt(struct crypto_tfm *tfm, u8 *out, const u8 *in)
 217 {
 218         struct geode_aes_op *op = crypto_tfm_ctx(tfm);
 219
 220         if (unlikely(op->keylen != AES_KEYSIZE_128)) {
 221                 crypto_cipher_encrypt_one(op->fallback.cip, out, in);
 222                 return;
 223         }
 224
 225         op->src = (void *) in;
 226         op->dst = (void *) out;
 227         op->mode = AES_MODE_ECB;
 228         op->flags = 0;
 229         op->len = AES_MIN_BLOCK_SIZE;
 230         op->dir = AES_DIR_ENCRYPT;
 231
 232         geode_aes_crypt(op);
 233 }
 234
 235
 236 static void
 237 geode_decrypt(struct crypto_tfm *tfm, u8 *out, const u8 *in)
 238 {
 239         struct geode_aes_op *op = crypto_tfm_ctx(tfm);
 240
 241         if (unlikely(op->keylen != AES_KEYSIZE_128)) {
 242                 crypto_cipher_decrypt_one(op->fallback.cip, out, in);
 243                 return;
 244         }
 245
 246         op->src = (void *) in;
 247         op->dst = (void *) out;
 248         op->mode = AES_MODE_ECB;
 249         op->flags = 0;
 250         op->len = AES_MIN_BLOCK_SIZE;
 251         op->dir = AES_DIR_DECRYPT;
 252
 253         geode_aes_crypt(op);
 254 }
 255
 256 static int fallback_init_cip(struct crypto_tfm *tfm)
 257 {
 258         const char *name = tfm->__crt_alg->cra_name;
 259         struct geode_aes_op *op = crypto_tfm_ctx(tfm);
 260
 261         op->fallback.cip = crypto_alloc_cipher(name, 0,
 262                                 CRYPTO_ALG_ASYNC | CRYPTO_ALG_NEED_FALLBACK);
 263
 264         if (IS_ERR(op->fallback.cip)) {
 265                 printk(KERN_ERR "Error allocating fallback algo %s\n", name);
 266                 return PTR_ERR(op->fallback.cip);
 267         }
 268
 269         return 0;
 270 }
 271
 272 static void fallback_exit_cip(struct crypto_tfm *tfm)
 273 {
 274         struct geode_aes_op *op = crypto_tfm_ctx(tfm);
 275
 276         crypto_free_cipher(op->fallback.cip);
 277         op->fallback.cip = NULL;
 278 }
 279
 280 static struct crypto_alg geode_alg = {
 281         .cra_name                       =       "aes",
 282         .cra_driver_name        =       "geode-aes",
 283         .cra_priority           =       300,
 284         .cra_alignmask          =       15,
 285         .cra_flags                      =       CRYPTO_ALG_TYPE_CIPHER |
 286                                                         CRYPTO_ALG_NEED_FALLBACK,
 287         .cra_init                       =       fallback_init_cip,
 288         .cra_exit                       =       fallback_exit_cip,
 289         .cra_blocksize          =       AES_MIN_BLOCK_SIZE,
 290         .cra_ctxsize            =       sizeof(struct geode_aes_op),
 291         .cra_module                     =       THIS_MODULE,
 292         .cra_list                       =       LIST_HEAD_INIT(geode_alg.cra_list),
 293         .cra_u                          =       {
 294                 .cipher =       {
 295                         .cia_min_keysize        =       AES_MIN_KEY_SIZE,
 296                         .cia_max_keysize        =       AES_MAX_KEY_SIZE,
 297                         .cia_setkey                     =       geode_setkey_cip,
 298                         .cia_encrypt            =       geode_encrypt,
 299                         .cia_decrypt            =       geode_decrypt
 300                 }
 301         }
 302 };
 303
 304 static int
 305 geode_cbc_decrypt(struct blkcipher_desc *desc,
 306                   struct scatterlist *dst, struct scatterlist *src,
 307                   unsigned int nbytes)
 308 {
 309         struct geode_aes_op *op = crypto_blkcipher_ctx(desc->tfm);
 310         struct blkcipher_walk walk;
 311         int err, ret;
 312
 313         if (unlikely(op->keylen != AES_KEYSIZE_128))
 314                 return fallback_blk_dec(desc, dst, src, nbytes);
 315
 316         blkcipher_walk_init(&walk, dst, src, nbytes);
 317         err = blkcipher_walk_virt(desc, &walk);
 318         op->iv = walk.iv;
 319
 320         while ((nbytes = walk.nbytes)) {
 321                 op->src = walk.src.virt.addr,
 322                 op->dst = walk.dst.virt.addr;
 323                 op->mode = AES_MODE_CBC;
 324                 op->len = nbytes - (nbytes % AES_MIN_BLOCK_SIZE);
 325                 op->dir = AES_DIR_DECRYPT;
 326
 327                 ret = geode_aes_crypt(op);
 328
 329                 nbytes -= ret;
 330                 err = blkcipher_walk_done(desc, &walk, nbytes);
 331         }
 332
 333         return err;
 334 }
 335
 336 static int
 337 geode_cbc_encrypt(struct blkcipher_desc *desc,
 338                   struct scatterlist *dst, struct scatterlist *src,
 339                   unsigned int nbytes)
 340 {
 341         struct geode_aes_op *op = crypto_blkcipher_ctx(desc->tfm);
 342         struct blkcipher_walk walk;
 343         int err, ret;
 344
 345         if (unlikely(op->keylen != AES_KEYSIZE_128))
 346                 return fallback_blk_enc(desc, dst, src, nbytes);
 347
 348         blkcipher_walk_init(&walk, dst, src, nbytes);
 349         err = blkcipher_walk_virt(desc, &walk);
 350         op->iv = walk.iv;
 351
 352         while ((nbytes = walk.nbytes)) {
 353                 op->src = walk.src.virt.addr,
 354                 op->dst = walk.dst.virt.addr;
 355                 op->mode = AES_MODE_CBC;
 356                 op->len = nbytes - (nbytes % AES_MIN_BLOCK_SIZE);
 357                 op->dir = AES_DIR_ENCRYPT;
 358
 359                 ret = geode_aes_crypt(op);
 360                 nbytes -= ret;
 361                 err = blkcipher_walk_done(desc, &walk, nbytes);
 362         }
 363
 364         return err;
 365 }
 366
 367 static int fallback_init_blk(struct crypto_tfm *tfm)
 368 {
 369         const char *name = tfm->__crt_alg->cra_name;
 370         struct geode_aes_op *op = crypto_tfm_ctx(tfm);
 371
 372         op->fallback.blk = crypto_alloc_blkcipher(name, 0,
 373                         CRYPTO_ALG_ASYNC | CRYPTO_ALG_NEED_FALLBACK);
 374
 375         if (IS_ERR(op->fallback.blk)) {
 376                 printk(KERN_ERR "Error allocating fallback algo %s\n", name);
 377                 return PTR_ERR(op->fallback.blk);
 378         }
 379
 380         return 0;
 381 }
 382
 383 static void fallback_exit_blk(struct crypto_tfm *tfm)
 384 {
 385         struct geode_aes_op *op = crypto_tfm_ctx(tfm);
 386
 387         crypto_free_blkcipher(op->fallback.blk);
 388         op->fallback.blk = NULL;
 389 }
 390
 391 static struct crypto_alg geode_cbc_alg = {
 392         .cra_name               =       "cbc(aes)",
 393         .cra_driver_name        =       "cbc-aes-geode",
 394         .cra_priority           =       400,
 395         .cra_flags                      =       CRYPTO_ALG_TYPE_BLKCIPHER |
 396                                                 CRYPTO_ALG_KERN_DRIVER_ONLY |
 397                                                 CRYPTO_ALG_NEED_FALLBACK,
 398         .cra_init                       =       fallback_init_blk,
 399         .cra_exit                       =       fallback_exit_blk,
 400         .cra_blocksize          =       AES_MIN_BLOCK_SIZE,
 401         .cra_ctxsize            =       sizeof(struct geode_aes_op),
 402         .cra_alignmask          =       15,
 403         .cra_type                       =       &crypto_blkcipher_type,
 404         .cra_module                     =       THIS_MODULE,
 405         .cra_list                       =       LIST_HEAD_INIT(geode_cbc_alg.cra_list),
 406         .cra_u                          =       {
 407                 .blkcipher      =       {
 408                         .min_keysize    =       AES_MIN_KEY_SIZE,
 409                         .max_keysize    =       AES_MAX_KEY_SIZE,
 410                         .setkey                 =       geode_setkey_blk,
 411                         .encrypt                =       geode_cbc_encrypt,
 412                         .decrypt                =       geode_cbc_decrypt,
 413                         .ivsize                 =       AES_IV_LENGTH,
 414                 }
 415         }
 416 };
 417
 418 static int
 419 geode_ecb_decrypt(struct blkcipher_desc *desc,
 420                   struct scatterlist *dst, struct scatterlist *src,
 421                   unsigned int nbytes)
 422 {
 423         struct geode_aes_op *op = crypto_blkcipher_ctx(desc->tfm);
 424         struct blkcipher_walk walk;
 425         int err, ret;
 426
 427         if (unlikely(op->keylen != AES_KEYSIZE_128))
 428                 return fallback_blk_dec(desc, dst, src, nbytes);
 429
 430         blkcipher_walk_init(&walk, dst, src, nbytes);
 431         err = blkcipher_walk_virt(desc, &walk);
 432
 433         while ((nbytes = walk.nbytes)) {
 434                 op->src = walk.src.virt.addr,
 435                 op->dst = walk.dst.virt.addr;
 436                 op->mode = AES_MODE_ECB;
 437                 op->len = nbytes - (nbytes % AES_MIN_BLOCK_SIZE);
 438                 op->dir = AES_DIR_DECRYPT;
 439
 440                 ret = geode_aes_crypt(op);
 441                 nbytes -= ret;
 442                 err = blkcipher_walk_done(desc, &walk, nbytes);
 443         }
 444
 445         return err;
 446 }
 447
 448 static int
 449 geode_ecb_encrypt(struct blkcipher_desc *desc,
 450                   struct scatterlist *dst, struct scatterlist *src,
 451                   unsigned int nbytes)
 452 {
 453         struct geode_aes_op *op = crypto_blkcipher_ctx(desc->tfm);
 454         struct blkcipher_walk walk;
 455         int err, ret;
 456
 457         if (unlikely(op->keylen != AES_KEYSIZE_128))
 458                 return fallback_blk_enc(desc, dst, src, nbytes);
 459
 460         blkcipher_walk_init(&walk, dst, src, nbytes);
 461         err = blkcipher_walk_virt(desc, &walk);
 462
 463         while ((nbytes = walk.nbytes)) {
 464                 op->src = walk.src.virt.addr,
 465                 op->dst = walk.dst.virt.addr;
 466                 op->mode = AES_MODE_ECB;
 467                 op->len = nbytes - (nbytes % AES_MIN_BLOCK_SIZE);
 468                 op->dir = AES_DIR_ENCRYPT;
 469
 470                 ret = geode_aes_crypt(op);
 471                 nbytes -= ret;
 472                 ret =  blkcipher_walk_done(desc, &walk, nbytes);
 473         }
 474
 475         return err;
 476 }
 477
 478 static struct crypto_alg geode_ecb_alg = {
 479         .cra_name                       =       "ecb(aes)",
 480         .cra_driver_name        =       "ecb-aes-geode",
 481         .cra_priority           =       400,
 482         .cra_flags                      =       CRYPTO_ALG_TYPE_BLKCIPHER |
 483                                                 CRYPTO_ALG_KERN_DRIVER_ONLY |
 484                                                 CRYPTO_ALG_NEED_FALLBACK,
 485         .cra_init                       =       fallback_init_blk,
 486         .cra_exit                       =       fallback_exit_blk,
 487         .cra_blocksize          =       AES_MIN_BLOCK_SIZE,
 488         .cra_ctxsize            =       sizeof(struct geode_aes_op),
 489         .cra_alignmask          =       15,
 490         .cra_type                       =       &crypto_blkcipher_type,
 491         .cra_module                     =       THIS_MODULE,
 492         .cra_list                       =       LIST_HEAD_INIT(geode_ecb_alg.cra_list),
 493         .cra_u                          =       {
 494                 .blkcipher      =       {
 495                         .min_keysize    =       AES_MIN_KEY_SIZE,
 496                         .max_keysize    =       AES_MAX_KEY_SIZE,
 497                         .setkey                 =       geode_setkey_blk,
 498                         .encrypt                =       geode_ecb_encrypt,
 499                         .decrypt                =       geode_ecb_decrypt,
 500                 }
 501         }
 502 };
 503
 504 static void __devexit
 505 geode_aes_remove(struct pci_dev *dev)
 506 {
 507         crypto_unregister_alg(&geode_alg);
 508         crypto_unregister_alg(&geode_ecb_alg);
 509         crypto_unregister_alg(&geode_cbc_alg);
 510
 511         pci_iounmap(dev, _iobase);
 512         _iobase = NULL;
 513
 514         pci_release_regions(dev);
 515         pci_disable_device(dev);
 516 }
 517
 518
 519 static int __devinit
 520 geode_aes_probe(struct pci_dev *dev, const struct pci_device_id *id)
 521 {
 522         int ret;
 523         ret = pci_enable_device(dev);
 524         if (ret)
 525                 return ret;
 526
 527         ret = pci_request_regions(dev, "geode-aes");
 528         if (ret)
 529                 goto eenable;
 530
 531         _iobase = pci_iomap(dev, 0, 0);
 532
 533         if (_iobase == NULL) {
 534                 ret = -ENOMEM;
 535                 goto erequest;
 536         }
 537
 538         spin_lock_init(&lock);
 539
 540         /* Clear any pending activity */
 541         iowrite32(AES_INTR_PENDING | AES_INTR_MASK, _iobase + AES_INTR_REG);
 542
 543         ret = crypto_register_alg(&geode_alg);
 544         if (ret)
 545                 goto eiomap;
 546
 547         ret = crypto_register_alg(&geode_ecb_alg);
 548         if (ret)
 549                 goto ealg;
 550
 551         ret = crypto_register_alg(&geode_cbc_alg);
 552         if (ret)
 553                 goto eecb;
 554
 555         printk(KERN_NOTICE "geode-aes: GEODE AES engine enabled.\n");
 556         return 0;
 557
 558  eecb:
 559         crypto_unregister_alg(&geode_ecb_alg);
 560
 561  ealg:
 562         crypto_unregister_alg(&geode_alg);
 563
 564  eiomap:
 565         pci_iounmap(dev, _iobase);
 566
 567  erequest:
 568         pci_release_regions(dev);
 569
 570  eenable:
 571         pci_disable_device(dev);
 572
 573         printk(KERN_ERR "geode-aes:  GEODE AES initialization failed.\n");
 574         return ret;
 575 }
 576
 577 static struct pci_device_id geode_aes_tbl[] = {
 578         { PCI_VDEVICE(AMD, PCI_DEVICE_ID_AMD_LX_AES), } ,
 579         { 0, }
 580 };
 581
 582 MODULE_DEVICE_TABLE(pci, geode_aes_tbl);
 583
 584 static struct pci_driver geode_aes_driver = {
 585         .name = "Geode LX AES",
 586         .id_table = geode_aes_tbl,
 587         .probe = geode_aes_probe,
 588         .remove = __devexit_p(geode_aes_remove)
 589 };
 590
 591 static int __init
 592 geode_aes_init(void)
 593 {
 594         return pci_register_driver(&geode_aes_driver);
 595 }
 596
 597 static void __exit
 598 geode_aes_exit(void)
 599 {
 600         pci_unregister_driver(&geode_aes_driver);
 601 }
 602
 603 MODULE_AUTHOR("Advanced Micro Devices, Inc.");
 604 MODULE_DESCRIPTION("Geode LX Hardware AES driver");
 605 MODULE_LICENSE("GPL");
 606
 607 module_init(geode_aes_init);
 608 module_exit(geode_aes_exit);