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 <asm/io.h>
  19 #include <asm/delay.h>
  20
  21 #include "geode-aes.h"
  22
  23 /* Register definitions */
  24
  25 #define AES_CTRLA_REG  0x0000
  26
  27 #define AES_CTRL_START     0x01
  28 #define AES_CTRL_DECRYPT   0x00
  29 #define AES_CTRL_ENCRYPT   0x02
  30 #define AES_CTRL_WRKEY     0x04
  31 #define AES_CTRL_DCA       0x08
  32 #define AES_CTRL_SCA       0x10
  33 #define AES_CTRL_CBC       0x20
  34
  35 #define AES_INTR_REG  0x0008
  36
  37 #define AES_INTRA_PENDING (1 << 16)
  38 #define AES_INTRB_PENDING (1 << 17)
  39
  40 #define AES_INTR_PENDING  (AES_INTRA_PENDING | AES_INTRB_PENDING)
  41 #define AES_INTR_MASK     0x07
  42
  43 #define AES_SOURCEA_REG   0x0010
  44 #define AES_DSTA_REG      0x0014
  45 #define AES_LENA_REG      0x0018
  46 #define AES_WRITEKEY0_REG 0x0030
  47 #define AES_WRITEIV0_REG  0x0040
  48
  49 /*  A very large counter that is used to gracefully bail out of an
  50  *  operation in case of trouble
  51  */
  52
  53 #define AES_OP_TIMEOUT    0x50000
  54
  55 /* Static structures */
  56
  57 static void __iomem * _iobase;
  58 static spinlock_t lock;
  59
  60 /* Write a 128 bit field (either a writable key or IV) */
  61 static inline void
  62 _writefield(u32 offset, void *value)
  63 {
  64         int i;
  65         for(i = 0; i < 4; i++)
  66                 iowrite32(((u32 *) value)[i], _iobase + offset + (i * 4));
  67 }
  68
  69 /* Read a 128 bit field (either a writable key or IV) */
  70 static inline void
  71 _readfield(u32 offset, void *value)
  72 {
  73         int i;
  74         for(i = 0; i < 4; i++)
  75                 ((u32 *) value)[i] = ioread32(_iobase + offset + (i * 4));
  76 }
  77
  78 static int
  79 do_crypt(void *src, void *dst, int len, u32 flags)
  80 {
  81         u32 status;
  82         u32 counter = AES_OP_TIMEOUT;
  83
  84         iowrite32(virt_to_phys(src), _iobase + AES_SOURCEA_REG);
  85         iowrite32(virt_to_phys(dst), _iobase + AES_DSTA_REG);
  86         iowrite32(len,  _iobase + AES_LENA_REG);
  87
  88         /* Start the operation */
  89         iowrite32(AES_CTRL_START | flags, _iobase + AES_CTRLA_REG);
  90
  91         do {
  92                 status = ioread32(_iobase + AES_INTR_REG);
  93                 cpu_relax();
  94         } while(!(status & AES_INTRA_PENDING) && --counter);
  95
  96         /* Clear the event */
  97         iowrite32((status & 0xFF) | AES_INTRA_PENDING, _iobase + AES_INTR_REG);
  98         return counter ? 0 : 1;
  99 }
 100
 101 static unsigned int
 102 geode_aes_crypt(struct geode_aes_op *op)
 103 {
 104         u32 flags = 0;
 105         unsigned long iflags;
 106         int ret;
 107
 108         if (op->len == 0)
 109                 return 0;
 110
 111         /* If the source and destination is the same, then
 112          * we need to turn on the coherent flags, otherwise
 113          * we don't need to worry
 114          */
 115
 116         flags |= (AES_CTRL_DCA | AES_CTRL_SCA);
 117
 118         if (op->dir == AES_DIR_ENCRYPT)
 119                 flags |= AES_CTRL_ENCRYPT;
 120
 121         /* Start the critical section */
 122
 123         spin_lock_irqsave(&lock, iflags);
 124
 125         if (op->mode == AES_MODE_CBC) {
 126                 flags |= AES_CTRL_CBC;
 127                 _writefield(AES_WRITEIV0_REG, op->iv);
 128         }
 129
 130         if (!(op->flags & AES_FLAGS_HIDDENKEY)) {
 131                 flags |= AES_CTRL_WRKEY;
 132                 _writefield(AES_WRITEKEY0_REG, op->key);
 133         }
 134
 135         ret = do_crypt(op->src, op->dst, op->len, flags);
 136         BUG_ON(ret);
 137
 138         if (op->mode == AES_MODE_CBC)
 139                 _readfield(AES_WRITEIV0_REG, op->iv);
 140
 141         spin_unlock_irqrestore(&lock, iflags);
 142
 143         return op->len;
 144 }
 145
 146 /* CRYPTO-API Functions */
 147
 148 static int
 149 geode_setkey(struct crypto_tfm *tfm, const u8 *key, unsigned int len)
 150 {
 151         struct geode_aes_op *op = crypto_tfm_ctx(tfm);
 152
 153         if (len != AES_KEY_LENGTH) {
 154                 tfm->crt_flags |= CRYPTO_TFM_RES_BAD_KEY_LEN;
 155                 return -EINVAL;
 156         }
 157
 158         memcpy(op->key, key, len);
 159         return 0;
 160 }
 161
 162 static void
 163 geode_encrypt(struct crypto_tfm *tfm, u8 *out, const u8 *in)
 164 {
 165         struct geode_aes_op *op = crypto_tfm_ctx(tfm);
 166
 167         if ((out == NULL) || (in == NULL))
 168                 return;
 169
 170         op->src = (void *) in;
 171         op->dst = (void *) out;
 172         op->mode = AES_MODE_ECB;
 173         op->flags = 0;
 174         op->len = AES_MIN_BLOCK_SIZE;
 175         op->dir = AES_DIR_ENCRYPT;
 176
 177         geode_aes_crypt(op);
 178 }
 179
 180
 181 static void
 182 geode_decrypt(struct crypto_tfm *tfm, u8 *out, const u8 *in)
 183 {
 184         struct geode_aes_op *op = crypto_tfm_ctx(tfm);
 185
 186         if ((out == NULL) || (in == NULL))
 187                 return;
 188
 189         op->src = (void *) in;
 190         op->dst = (void *) out;
 191         op->mode = AES_MODE_ECB;
 192         op->flags = 0;
 193         op->len = AES_MIN_BLOCK_SIZE;
 194         op->dir = AES_DIR_DECRYPT;
 195
 196         geode_aes_crypt(op);
 197 }
 198
 199
 200 static struct crypto_alg geode_alg = {
 201         .cra_name               =       "aes",
 202         .cra_driver_name        =       "geode-aes-128",
 203         .cra_priority           =       300,
 204         .cra_alignmask          =       15,
 205         .cra_flags              =       CRYPTO_ALG_TYPE_CIPHER,
 206         .cra_blocksize          =       AES_MIN_BLOCK_SIZE,
 207         .cra_ctxsize            =       sizeof(struct geode_aes_op),
 208         .cra_module             =       THIS_MODULE,
 209         .cra_list               =       LIST_HEAD_INIT(geode_alg.cra_list),
 210         .cra_u                  =       {
 211                 .cipher = {
 212                         .cia_min_keysize        =  AES_KEY_LENGTH,
 213                         .cia_max_keysize        =  AES_KEY_LENGTH,
 214                         .cia_setkey             =  geode_setkey,
 215                         .cia_encrypt            =  geode_encrypt,
 216                         .cia_decrypt            =  geode_decrypt
 217                 }
 218         }
 219 };
 220
 221 static int
 222 geode_cbc_decrypt(struct blkcipher_desc *desc,
 223                   struct scatterlist *dst, struct scatterlist *src,
 224                   unsigned int nbytes)
 225 {
 226         struct geode_aes_op *op = crypto_blkcipher_ctx(desc->tfm);
 227         struct blkcipher_walk walk;
 228         int err, ret;
 229
 230         blkcipher_walk_init(&walk, dst, src, nbytes);
 231         err = blkcipher_walk_virt(desc, &walk);
 232         memcpy(op->iv, walk.iv, AES_IV_LENGTH);
 233
 234         while((nbytes = walk.nbytes)) {
 235                 op->src = walk.src.virt.addr,
 236                 op->dst = walk.dst.virt.addr;
 237                 op->mode = AES_MODE_CBC;
 238                 op->len = nbytes - (nbytes % AES_MIN_BLOCK_SIZE);
 239                 op->dir = AES_DIR_DECRYPT;
 240
 241                 ret = geode_aes_crypt(op);
 242
 243                 nbytes -= ret;
 244                 err = blkcipher_walk_done(desc, &walk, nbytes);
 245         }
 246
 247         memcpy(walk.iv, op->iv, AES_IV_LENGTH);
 248         return err;
 249 }
 250
 251 static int
 252 geode_cbc_encrypt(struct blkcipher_desc *desc,
 253                   struct scatterlist *dst, struct scatterlist *src,
 254                   unsigned int nbytes)
 255 {
 256         struct geode_aes_op *op = crypto_blkcipher_ctx(desc->tfm);
 257         struct blkcipher_walk walk;
 258         int err, ret;
 259
 260         blkcipher_walk_init(&walk, dst, src, nbytes);
 261         err = blkcipher_walk_virt(desc, &walk);
 262         memcpy(op->iv, walk.iv, AES_IV_LENGTH);
 263
 264         while((nbytes = walk.nbytes)) {
 265                 op->src = walk.src.virt.addr,
 266                 op->dst = walk.dst.virt.addr;
 267                 op->mode = AES_MODE_CBC;
 268                 op->len = nbytes - (nbytes % AES_MIN_BLOCK_SIZE);
 269                 op->dir = AES_DIR_ENCRYPT;
 270
 271                 ret = geode_aes_crypt(op);
 272                 nbytes -= ret;
 273                 err = blkcipher_walk_done(desc, &walk, nbytes);
 274         }
 275
 276         memcpy(walk.iv, op->iv, AES_IV_LENGTH);
 277         return err;
 278 }
 279
 280 static struct crypto_alg geode_cbc_alg = {
 281         .cra_name               =       "cbc(aes)",
 282         .cra_driver_name        =       "cbc-aes-geode-128",
 283         .cra_priority           =       400,
 284         .cra_flags              =       CRYPTO_ALG_TYPE_BLKCIPHER,
 285         .cra_blocksize          =       AES_MIN_BLOCK_SIZE,
 286         .cra_ctxsize            =       sizeof(struct geode_aes_op),
 287         .cra_alignmask          =       15,
 288         .cra_type               =       &crypto_blkcipher_type,
 289         .cra_module             =       THIS_MODULE,
 290         .cra_list               =       LIST_HEAD_INIT(geode_cbc_alg.cra_list),
 291         .cra_u                  =       {
 292                 .blkcipher = {
 293                         .min_keysize            =       AES_KEY_LENGTH,
 294                         .max_keysize            =       AES_KEY_LENGTH,
 295                         .setkey                 =       geode_setkey,
 296                         .encrypt                =       geode_cbc_encrypt,
 297                         .decrypt                =       geode_cbc_decrypt,
 298                         .ivsize                 =       AES_IV_LENGTH,
 299                 }
 300         }
 301 };
 302
 303 static int
 304 geode_ecb_decrypt(struct blkcipher_desc *desc,
 305                   struct scatterlist *dst, struct scatterlist *src,
 306                   unsigned int nbytes)
 307 {
 308         struct geode_aes_op *op = crypto_blkcipher_ctx(desc->tfm);
 309         struct blkcipher_walk walk;
 310         int err, ret;
 311
 312         blkcipher_walk_init(&walk, dst, src, nbytes);
 313         err = blkcipher_walk_virt(desc, &walk);
 314
 315         while((nbytes = walk.nbytes)) {
 316                 op->src = walk.src.virt.addr,
 317                 op->dst = walk.dst.virt.addr;
 318                 op->mode = AES_MODE_ECB;
 319                 op->len = nbytes - (nbytes % AES_MIN_BLOCK_SIZE);
 320                 op->dir = AES_DIR_DECRYPT;
 321
 322                 ret = geode_aes_crypt(op);
 323                 nbytes -= ret;
 324                 err = blkcipher_walk_done(desc, &walk, nbytes);
 325         }
 326
 327         return err;
 328 }
 329
 330 static int
 331 geode_ecb_encrypt(struct blkcipher_desc *desc,
 332                   struct scatterlist *dst, struct scatterlist *src,
 333                   unsigned int nbytes)
 334 {
 335         struct geode_aes_op *op = crypto_blkcipher_ctx(desc->tfm);
 336         struct blkcipher_walk walk;
 337         int err, ret;
 338
 339         blkcipher_walk_init(&walk, dst, src, nbytes);
 340         err = blkcipher_walk_virt(desc, &walk);
 341
 342         while((nbytes = walk.nbytes)) {
 343                 op->src = walk.src.virt.addr,
 344                 op->dst = walk.dst.virt.addr;
 345                 op->mode = AES_MODE_ECB;
 346                 op->len = nbytes - (nbytes % AES_MIN_BLOCK_SIZE);
 347                 op->dir = AES_DIR_ENCRYPT;
 348
 349                 ret = geode_aes_crypt(op);
 350                 nbytes -= ret;
 351                 ret =  blkcipher_walk_done(desc, &walk, nbytes);
 352         }
 353
 354         return err;
 355 }
 356
 357 static struct crypto_alg geode_ecb_alg = {
 358         .cra_name               =       "ecb(aes)",
 359         .cra_driver_name        =       "ecb-aes-geode-128",
 360         .cra_priority           =       400,
 361         .cra_flags              =       CRYPTO_ALG_TYPE_BLKCIPHER,
 362         .cra_blocksize          =       AES_MIN_BLOCK_SIZE,
 363         .cra_ctxsize            =       sizeof(struct geode_aes_op),
 364         .cra_alignmask          =       15,
 365         .cra_type               =       &crypto_blkcipher_type,
 366         .cra_module             =       THIS_MODULE,
 367         .cra_list               =       LIST_HEAD_INIT(geode_ecb_alg.cra_list),
 368         .cra_u                  =       {
 369                 .blkcipher = {
 370                         .min_keysize            =       AES_KEY_LENGTH,
 371                         .max_keysize            =       AES_KEY_LENGTH,
 372                         .setkey                 =       geode_setkey,
 373                         .encrypt                =       geode_ecb_encrypt,
 374                         .decrypt                =       geode_ecb_decrypt,
 375                 }
 376         }
 377 };
 378
 379 static void
 380 geode_aes_remove(struct pci_dev *dev)
 381 {
 382         crypto_unregister_alg(&geode_alg);
 383         crypto_unregister_alg(&geode_ecb_alg);
 384         crypto_unregister_alg(&geode_cbc_alg);
 385
 386         pci_iounmap(dev, _iobase);
 387         _iobase = NULL;
 388
 389         pci_release_regions(dev);
 390         pci_disable_device(dev);
 391 }
 392
 393
 394 static int
 395 geode_aes_probe(struct pci_dev *dev, const struct pci_device_id *id)
 396 {
 397         int ret;
 398
 399         if ((ret = pci_enable_device(dev)))
 400                 return ret;
 401
 402         if ((ret = pci_request_regions(dev, "geode-aes-128")))
 403                 goto eenable;
 404
 405         _iobase = pci_iomap(dev, 0, 0);
 406
 407         if (_iobase == NULL) {
 408                 ret = -ENOMEM;
 409                 goto erequest;
 410         }
 411
 412         spin_lock_init(&lock);
 413
 414         /* Clear any pending activity */
 415         iowrite32(AES_INTR_PENDING | AES_INTR_MASK, _iobase + AES_INTR_REG);
 416
 417         if ((ret = crypto_register_alg(&geode_alg)))
 418                 goto eiomap;
 419
 420         if ((ret = crypto_register_alg(&geode_ecb_alg)))
 421                 goto ealg;
 422
 423         if ((ret = crypto_register_alg(&geode_cbc_alg)))
 424                 goto eecb;
 425
 426         printk(KERN_NOTICE "geode-aes: GEODE AES engine enabled.\n");
 427         return 0;
 428
 429  eecb:
 430         crypto_unregister_alg(&geode_ecb_alg);
 431
 432  ealg:
 433         crypto_unregister_alg(&geode_alg);
 434
 435  eiomap:
 436         pci_iounmap(dev, _iobase);
 437
 438  erequest:
 439         pci_release_regions(dev);
 440
 441  eenable:
 442         pci_disable_device(dev);
 443
 444         printk(KERN_ERR "geode-aes:  GEODE AES initialization failed.\n");
 445         return ret;
 446 }
 447
 448 static struct pci_device_id geode_aes_tbl[] = {
 449         { PCI_VENDOR_ID_AMD, PCI_DEVICE_ID_AMD_LX_AES, PCI_ANY_ID, PCI_ANY_ID} ,
 450         { 0, }
 451 };
 452
 453 MODULE_DEVICE_TABLE(pci, geode_aes_tbl);
 454
 455 static struct pci_driver geode_aes_driver = {
 456         .name = "Geode LX AES",
 457         .id_table = geode_aes_tbl,
 458         .probe = geode_aes_probe,
 459         .remove = __devexit_p(geode_aes_remove)
 460 };
 461
 462 static int __init
 463 geode_aes_init(void)
 464 {
 465         return pci_register_driver(&geode_aes_driver);
 466 }
 467
 468 static void __exit
 469 geode_aes_exit(void)
 470 {
 471         pci_unregister_driver(&geode_aes_driver);
 472 }
 473
 474 MODULE_AUTHOR("Advanced Micro Devices, Inc.");
 475 MODULE_DESCRIPTION("Geode LX Hardware AES driver");
 476 MODULE_LICENSE("GPL");
 477
 478 module_init(geode_aes_init);
 479 module_exit(geode_aes_exit);