drivers/crypto/geode-aes.c

   1 // SPDX-License-Identifier: GPL-2.0-or-later
   2  /* Copyright (C) 2004-2006, Advanced Micro Devices, Inc.
   3   */
   4
   5 #include <linux/module.h>
   6 #include <linux/kernel.h>
   7 #include <linux/pci.h>
   8 #include <linux/pci_ids.h>
   9 #include <linux/crypto.h>
  10 #include <linux/spinlock.h>
  11 #include <crypto/algapi.h>
  12 #include <crypto/aes.h>
  13 #include <crypto/internal/skcipher.h>
  14
  15 #include <linux/io.h>
  16 #include <linux/delay.h>
  17
  18 #include "geode-aes.h"
  19
  20 /* Static structures */
  21
  22 static void __iomem *_iobase;
  23 static spinlock_t lock;
  24
  25 /* Write a 128 bit field (either a writable key or IV) */
  26 static inline void
  27 _writefield(u32 offset, const void *value)
  28 {
  29         int i;
  30
  31         for (i = 0; i < 4; i++)
  32                 iowrite32(((const u32 *) value)[i], _iobase + offset + (i * 4));
  33 }
  34
  35 /* Read a 128 bit field (either a writable key or IV) */
  36 static inline void
  37 _readfield(u32 offset, void *value)
  38 {
  39         int i;
  40
  41         for (i = 0; i < 4; i++)
  42                 ((u32 *) value)[i] = ioread32(_iobase + offset + (i * 4));
  43 }
  44
  45 static int
  46 do_crypt(const void *src, void *dst, u32 len, u32 flags)
  47 {
  48         u32 status;
  49         u32 counter = AES_OP_TIMEOUT;
  50
  51         iowrite32(virt_to_phys((void *)src), _iobase + AES_SOURCEA_REG);
  52         iowrite32(virt_to_phys(dst), _iobase + AES_DSTA_REG);
  53         iowrite32(len,  _iobase + AES_LENA_REG);
  54
  55         /* Start the operation */
  56         iowrite32(AES_CTRL_START | flags, _iobase + AES_CTRLA_REG);
  57
  58         do {
  59                 status = ioread32(_iobase + AES_INTR_REG);
  60                 cpu_relax();
  61         } while (!(status & AES_INTRA_PENDING) && --counter);
  62
  63         /* Clear the event */
  64         iowrite32((status & 0xFF) | AES_INTRA_PENDING, _iobase + AES_INTR_REG);
  65         return counter ? 0 : 1;
  66 }
  67
  68 static void
  69 geode_aes_crypt(const struct geode_aes_tfm_ctx *tctx, const void *src,
  70                 void *dst, u32 len, u8 *iv, int mode, int dir)
  71 {
  72         u32 flags = 0;
  73         unsigned long iflags;
  74         int ret;
  75
  76         /* If the source and destination is the same, then
  77          * we need to turn on the coherent flags, otherwise
  78          * we don't need to worry
  79          */
  80
  81         flags |= (AES_CTRL_DCA | AES_CTRL_SCA);
  82
  83         if (dir == AES_DIR_ENCRYPT)
  84                 flags |= AES_CTRL_ENCRYPT;
  85
  86         /* Start the critical section */
  87
  88         spin_lock_irqsave(&lock, iflags);
  89
  90         if (mode == AES_MODE_CBC) {
  91                 flags |= AES_CTRL_CBC;
  92                 _writefield(AES_WRITEIV0_REG, iv);
  93         }
  94
  95         flags |= AES_CTRL_WRKEY;
  96         _writefield(AES_WRITEKEY0_REG, tctx->key);
  97
  98         ret = do_crypt(src, dst, len, flags);
  99         BUG_ON(ret);
 100
 101         if (mode == AES_MODE_CBC)
 102                 _readfield(AES_WRITEIV0_REG, iv);
 103
 104         spin_unlock_irqrestore(&lock, iflags);
 105 }
 106
 107 /* CRYPTO-API Functions */
 108
 109 static int geode_setkey_cip(struct crypto_tfm *tfm, const u8 *key,
 110                 unsigned int len)
 111 {
 112         struct geode_aes_tfm_ctx *tctx = crypto_tfm_ctx(tfm);
 113
 114         tctx->keylen = len;
 115
 116         if (len == AES_KEYSIZE_128) {
 117                 memcpy(tctx->key, key, len);
 118                 return 0;
 119         }
 120
 121         if (len != AES_KEYSIZE_192 && len != AES_KEYSIZE_256)
 122                 /* not supported at all */
 123                 return -EINVAL;
 124
 125         /*
 126          * The requested key size is not supported by HW, do a fallback
 127          */
 128         tctx->fallback.cip->base.crt_flags &= ~CRYPTO_TFM_REQ_MASK;
 129         tctx->fallback.cip->base.crt_flags |=
 130                 (tfm->crt_flags & CRYPTO_TFM_REQ_MASK);
 131
 132         return crypto_cipher_setkey(tctx->fallback.cip, key, len);
 133 }
 134
 135 static int geode_setkey_skcipher(struct crypto_skcipher *tfm, const u8 *key,
 136                                  unsigned int len)
 137 {
 138         struct geode_aes_tfm_ctx *tctx = crypto_skcipher_ctx(tfm);
 139
 140         tctx->keylen = len;
 141
 142         if (len == AES_KEYSIZE_128) {
 143                 memcpy(tctx->key, key, len);
 144                 return 0;
 145         }
 146
 147         if (len != AES_KEYSIZE_192 && len != AES_KEYSIZE_256)
 148                 /* not supported at all */
 149                 return -EINVAL;
 150
 151         /*
 152          * The requested key size is not supported by HW, do a fallback
 153          */
 154         crypto_skcipher_clear_flags(tctx->fallback.skcipher,
 155                                     CRYPTO_TFM_REQ_MASK);
 156         crypto_skcipher_set_flags(tctx->fallback.skcipher,
 157                                   crypto_skcipher_get_flags(tfm) &
 158                                   CRYPTO_TFM_REQ_MASK);
 159         return crypto_skcipher_setkey(tctx->fallback.skcipher, key, len);
 160 }
 161
 162 static void
 163 geode_encrypt(struct crypto_tfm *tfm, u8 *out, const u8 *in)
 164 {
 165         const struct geode_aes_tfm_ctx *tctx = crypto_tfm_ctx(tfm);
 166
 167         if (unlikely(tctx->keylen != AES_KEYSIZE_128)) {
 168                 crypto_cipher_encrypt_one(tctx->fallback.cip, out, in);
 169                 return;
 170         }
 171
 172         geode_aes_crypt(tctx, in, out, AES_BLOCK_SIZE, NULL,
 173                         AES_MODE_ECB, AES_DIR_ENCRYPT);
 174 }
 175
 176
 177 static void
 178 geode_decrypt(struct crypto_tfm *tfm, u8 *out, const u8 *in)
 179 {
 180         const struct geode_aes_tfm_ctx *tctx = crypto_tfm_ctx(tfm);
 181
 182         if (unlikely(tctx->keylen != AES_KEYSIZE_128)) {
 183                 crypto_cipher_decrypt_one(tctx->fallback.cip, out, in);
 184                 return;
 185         }
 186
 187         geode_aes_crypt(tctx, in, out, AES_BLOCK_SIZE, NULL,
 188                         AES_MODE_ECB, AES_DIR_DECRYPT);
 189 }
 190
 191 static int fallback_init_cip(struct crypto_tfm *tfm)
 192 {
 193         const char *name = crypto_tfm_alg_name(tfm);
 194         struct geode_aes_tfm_ctx *tctx = crypto_tfm_ctx(tfm);
 195
 196         tctx->fallback.cip = crypto_alloc_cipher(name, 0,
 197                                                  CRYPTO_ALG_NEED_FALLBACK);
 198
 199         if (IS_ERR(tctx->fallback.cip)) {
 200                 printk(KERN_ERR "Error allocating fallback algo %s\n", name);
 201                 return PTR_ERR(tctx->fallback.cip);
 202         }
 203
 204         return 0;
 205 }
 206
 207 static void fallback_exit_cip(struct crypto_tfm *tfm)
 208 {
 209         struct geode_aes_tfm_ctx *tctx = crypto_tfm_ctx(tfm);
 210
 211         crypto_free_cipher(tctx->fallback.cip);
 212 }
 213
 214 static struct crypto_alg geode_alg = {
 215         .cra_name                       =       "aes",
 216         .cra_driver_name        =       "geode-aes",
 217         .cra_priority           =       300,
 218         .cra_alignmask          =       15,
 219         .cra_flags                      =       CRYPTO_ALG_TYPE_CIPHER |
 220                                                         CRYPTO_ALG_NEED_FALLBACK,
 221         .cra_init                       =       fallback_init_cip,
 222         .cra_exit                       =       fallback_exit_cip,
 223         .cra_blocksize          =       AES_BLOCK_SIZE,
 224         .cra_ctxsize            =       sizeof(struct geode_aes_tfm_ctx),
 225         .cra_module                     =       THIS_MODULE,
 226         .cra_u                          =       {
 227                 .cipher =       {
 228                         .cia_min_keysize        =       AES_MIN_KEY_SIZE,
 229                         .cia_max_keysize        =       AES_MAX_KEY_SIZE,
 230                         .cia_setkey                     =       geode_setkey_cip,
 231                         .cia_encrypt            =       geode_encrypt,
 232                         .cia_decrypt            =       geode_decrypt
 233                 }
 234         }
 235 };
 236
 237 static int geode_init_skcipher(struct crypto_skcipher *tfm)
 238 {
 239         const char *name = crypto_tfm_alg_name(&tfm->base);
 240         struct geode_aes_tfm_ctx *tctx = crypto_skcipher_ctx(tfm);
 241
 242         tctx->fallback.skcipher =
 243                 crypto_alloc_skcipher(name, 0, CRYPTO_ALG_NEED_FALLBACK |
 244                                       CRYPTO_ALG_ASYNC);
 245         if (IS_ERR(tctx->fallback.skcipher)) {
 246                 printk(KERN_ERR "Error allocating fallback algo %s\n", name);
 247                 return PTR_ERR(tctx->fallback.skcipher);
 248         }
 249
 250         crypto_skcipher_set_reqsize(tfm, sizeof(struct skcipher_request) +
 251                                     crypto_skcipher_reqsize(tctx->fallback.skcipher));
 252         return 0;
 253 }
 254
 255 static void geode_exit_skcipher(struct crypto_skcipher *tfm)
 256 {
 257         struct geode_aes_tfm_ctx *tctx = crypto_skcipher_ctx(tfm);
 258
 259         crypto_free_skcipher(tctx->fallback.skcipher);
 260 }
 261
 262 static int geode_skcipher_crypt(struct skcipher_request *req, int mode, int dir)
 263 {
 264         struct crypto_skcipher *tfm = crypto_skcipher_reqtfm(req);
 265         const struct geode_aes_tfm_ctx *tctx = crypto_skcipher_ctx(tfm);
 266         struct skcipher_walk walk;
 267         unsigned int nbytes;
 268         int err;
 269
 270         if (unlikely(tctx->keylen != AES_KEYSIZE_128)) {
 271                 struct skcipher_request *subreq = skcipher_request_ctx(req);
 272
 273                 *subreq = *req;
 274                 skcipher_request_set_tfm(subreq, tctx->fallback.skcipher);
 275                 if (dir == AES_DIR_DECRYPT)
 276                         return crypto_skcipher_decrypt(subreq);
 277                 else
 278                         return crypto_skcipher_encrypt(subreq);
 279         }
 280
 281         err = skcipher_walk_virt(&walk, req, false);
 282
 283         while ((nbytes = walk.nbytes) != 0) {
 284                 geode_aes_crypt(tctx, walk.src.virt.addr, walk.dst.virt.addr,
 285                                 round_down(nbytes, AES_BLOCK_SIZE),
 286                                 walk.iv, mode, dir);
 287                 err = skcipher_walk_done(&walk, nbytes % AES_BLOCK_SIZE);
 288         }
 289
 290         return err;
 291 }
 292
 293 static int geode_cbc_encrypt(struct skcipher_request *req)
 294 {
 295         return geode_skcipher_crypt(req, AES_MODE_CBC, AES_DIR_ENCRYPT);
 296 }
 297
 298 static int geode_cbc_decrypt(struct skcipher_request *req)
 299 {
 300         return geode_skcipher_crypt(req, AES_MODE_CBC, AES_DIR_DECRYPT);
 301 }
 302
 303 static int geode_ecb_encrypt(struct skcipher_request *req)
 304 {
 305         return geode_skcipher_crypt(req, AES_MODE_ECB, AES_DIR_ENCRYPT);
 306 }
 307
 308 static int geode_ecb_decrypt(struct skcipher_request *req)
 309 {
 310         return geode_skcipher_crypt(req, AES_MODE_ECB, AES_DIR_DECRYPT);
 311 }
 312
 313 static struct skcipher_alg geode_skcipher_algs[] = {
 314         {
 315                 .base.cra_name          = "cbc(aes)",
 316                 .base.cra_driver_name   = "cbc-aes-geode",
 317                 .base.cra_priority      = 400,
 318                 .base.cra_flags         = CRYPTO_ALG_KERN_DRIVER_ONLY |
 319                                           CRYPTO_ALG_NEED_FALLBACK,
 320                 .base.cra_blocksize     = AES_BLOCK_SIZE,
 321                 .base.cra_ctxsize       = sizeof(struct geode_aes_tfm_ctx),
 322                 .base.cra_alignmask     = 15,
 323                 .base.cra_module        = THIS_MODULE,
 324                 .init                   = geode_init_skcipher,
 325                 .exit                   = geode_exit_skcipher,
 326                 .setkey                 = geode_setkey_skcipher,
 327                 .encrypt                = geode_cbc_encrypt,
 328                 .decrypt                = geode_cbc_decrypt,
 329                 .min_keysize            = AES_MIN_KEY_SIZE,
 330                 .max_keysize            = AES_MAX_KEY_SIZE,
 331                 .ivsize                 = AES_BLOCK_SIZE,
 332         }, {
 333                 .base.cra_name          = "ecb(aes)",
 334                 .base.cra_driver_name   = "ecb-aes-geode",
 335                 .base.cra_priority      = 400,
 336                 .base.cra_flags         = CRYPTO_ALG_KERN_DRIVER_ONLY |
 337                                           CRYPTO_ALG_NEED_FALLBACK,
 338                 .base.cra_blocksize     = AES_BLOCK_SIZE,
 339                 .base.cra_ctxsize       = sizeof(struct geode_aes_tfm_ctx),
 340                 .base.cra_alignmask     = 15,
 341                 .base.cra_module        = THIS_MODULE,
 342                 .init                   = geode_init_skcipher,
 343                 .exit                   = geode_exit_skcipher,
 344                 .setkey                 = geode_setkey_skcipher,
 345                 .encrypt                = geode_ecb_encrypt,
 346                 .decrypt                = geode_ecb_decrypt,
 347                 .min_keysize            = AES_MIN_KEY_SIZE,
 348                 .max_keysize            = AES_MAX_KEY_SIZE,
 349         },
 350 };
 351
 352 static void geode_aes_remove(struct pci_dev *dev)
 353 {
 354         crypto_unregister_alg(&geode_alg);
 355         crypto_unregister_skciphers(geode_skcipher_algs,
 356                                     ARRAY_SIZE(geode_skcipher_algs));
 357
 358         pci_iounmap(dev, _iobase);
 359         _iobase = NULL;
 360
 361         pci_release_regions(dev);
 362         pci_disable_device(dev);
 363 }
 364
 365
 366 static int geode_aes_probe(struct pci_dev *dev, const struct pci_device_id *id)
 367 {
 368         int ret;
 369
 370         ret = pci_enable_device(dev);
 371         if (ret)
 372                 return ret;
 373
 374         ret = pci_request_regions(dev, "geode-aes");
 375         if (ret)
 376                 goto eenable;
 377
 378         _iobase = pci_iomap(dev, 0, 0);
 379
 380         if (_iobase == NULL) {
 381                 ret = -ENOMEM;
 382                 goto erequest;
 383         }
 384
 385         spin_lock_init(&lock);
 386
 387         /* Clear any pending activity */
 388         iowrite32(AES_INTR_PENDING | AES_INTR_MASK, _iobase + AES_INTR_REG);
 389
 390         ret = crypto_register_alg(&geode_alg);
 391         if (ret)
 392                 goto eiomap;
 393
 394         ret = crypto_register_skciphers(geode_skcipher_algs,
 395                                         ARRAY_SIZE(geode_skcipher_algs));
 396         if (ret)
 397                 goto ealg;
 398
 399         dev_notice(&dev->dev, "GEODE AES engine enabled.\n");
 400         return 0;
 401
 402  ealg:
 403         crypto_unregister_alg(&geode_alg);
 404
 405  eiomap:
 406         pci_iounmap(dev, _iobase);
 407
 408  erequest:
 409         pci_release_regions(dev);
 410
 411  eenable:
 412         pci_disable_device(dev);
 413
 414         dev_err(&dev->dev, "GEODE AES initialization failed.\n");
 415         return ret;
 416 }
 417
 418 static struct pci_device_id geode_aes_tbl[] = {
 419         { PCI_VDEVICE(AMD, PCI_DEVICE_ID_AMD_LX_AES), },
 420         { 0, }
 421 };
 422
 423 MODULE_DEVICE_TABLE(pci, geode_aes_tbl);
 424
 425 static struct pci_driver geode_aes_driver = {
 426         .name = "Geode LX AES",
 427         .id_table = geode_aes_tbl,
 428         .probe = geode_aes_probe,
 429         .remove = geode_aes_remove,
 430 };
 431
 432 module_pci_driver(geode_aes_driver);
 433
 434 MODULE_AUTHOR("Advanced Micro Devices, Inc.");
 435 MODULE_DESCRIPTION("Geode LX Hardware AES driver");
 436 MODULE_LICENSE("GPL");