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