drivers/crypto/virtio/virtio_crypto_algs.c

   1  /* Algorithms supported by virtio crypto device
   2   *
   3   * Authors: Gonglei <arei.gonglei@huawei.com>
   4   *
   5   * Copyright 2016 HUAWEI TECHNOLOGIES CO., LTD.
   6   *
   7   * This program is free software; you can redistribute it and/or modify
   8   * it under the terms of the GNU General Public License as published by
   9   * the Free Software Foundation; either version 2 of the License, or
  10   * (at your option) any later version.
  11   *
  12   * This program is distributed in the hope that it will be useful,
  13   * but WITHOUT ANY WARRANTY; without even the implied warranty of
  14   * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  15   * GNU General Public License for more details.
  16   *
  17   * You should have received a copy of the GNU General Public License
  18   * along with this program; if not, see <http://www.gnu.org/licenses/>.
  19   */
  20
  21 #include <linux/scatterlist.h>
  22 #include <crypto/algapi.h>
  23 #include <linux/err.h>
  24 #include <crypto/scatterwalk.h>
  25 #include <linux/atomic.h>
  26
  27 #include <uapi/linux/virtio_crypto.h>
  28 #include "virtio_crypto_common.h"
  29
  30
  31 struct virtio_crypto_ablkcipher_ctx {
  32         struct virtio_crypto *vcrypto;
  33         struct crypto_tfm *tfm;
  34
  35         struct virtio_crypto_sym_session_info enc_sess_info;
  36         struct virtio_crypto_sym_session_info dec_sess_info;
  37 };
  38
  39 struct virtio_crypto_sym_request {
  40         struct virtio_crypto_request base;
  41
  42         /* Cipher or aead */
  43         uint32_t type;
  44         struct virtio_crypto_ablkcipher_ctx *ablkcipher_ctx;
  45         struct ablkcipher_request *ablkcipher_req;
  46         uint8_t *iv;
  47         /* Encryption? */
  48         bool encrypt;
  49 };
  50
  51 /*
  52  * The algs_lock protects the below global virtio_crypto_active_devs
  53  * and crypto algorithms registion.
  54  */
  55 static DEFINE_MUTEX(algs_lock);
  56 static unsigned int virtio_crypto_active_devs;
  57 static void virtio_crypto_ablkcipher_finalize_req(
  58         struct virtio_crypto_sym_request *vc_sym_req,
  59         struct ablkcipher_request *req,
  60         int err);
  61
  62 static void virtio_crypto_dataq_sym_callback
  63                 (struct virtio_crypto_request *vc_req, int len)
  64 {
  65         struct virtio_crypto_sym_request *vc_sym_req =
  66                 container_of(vc_req, struct virtio_crypto_sym_request, base);
  67         struct ablkcipher_request *ablk_req;
  68         int error;
  69
  70         /* Finish the encrypt or decrypt process */
  71         if (vc_sym_req->type == VIRTIO_CRYPTO_SYM_OP_CIPHER) {
  72                 switch (vc_req->status) {
  73                 case VIRTIO_CRYPTO_OK:
  74                         error = 0;
  75                         break;
  76                 case VIRTIO_CRYPTO_INVSESS:
  77                 case VIRTIO_CRYPTO_ERR:
  78                         error = -EINVAL;
  79                         break;
  80                 case VIRTIO_CRYPTO_BADMSG:
  81                         error = -EBADMSG;
  82                         break;
  83                 default:
  84                         error = -EIO;
  85                         break;
  86                 }
  87                 ablk_req = vc_sym_req->ablkcipher_req;
  88                 virtio_crypto_ablkcipher_finalize_req(vc_sym_req,
  89                                                         ablk_req, error);
  90         }
  91 }
  92
  93 static u64 virtio_crypto_alg_sg_nents_length(struct scatterlist *sg)
  94 {
  95         u64 total = 0;
  96
  97         for (total = 0; sg; sg = sg_next(sg))
  98                 total += sg->length;
  99
 100         return total;
 101 }
 102
 103 static int
 104 virtio_crypto_alg_validate_key(int key_len, uint32_t *alg)
 105 {
 106         switch (key_len) {
 107         case AES_KEYSIZE_128:
 108         case AES_KEYSIZE_192:
 109         case AES_KEYSIZE_256:
 110                 *alg = VIRTIO_CRYPTO_CIPHER_AES_CBC;
 111                 break;
 112         default:
 113                 return -EINVAL;
 114         }
 115         return 0;
 116 }
 117
 118 static int virtio_crypto_alg_ablkcipher_init_session(
 119                 struct virtio_crypto_ablkcipher_ctx *ctx,
 120                 uint32_t alg, const uint8_t *key,
 121                 unsigned int keylen,
 122                 int encrypt)
 123 {
 124         struct scatterlist outhdr, key_sg, inhdr, *sgs[3];
 125         unsigned int tmp;
 126         struct virtio_crypto *vcrypto = ctx->vcrypto;
 127         int op = encrypt ? VIRTIO_CRYPTO_OP_ENCRYPT : VIRTIO_CRYPTO_OP_DECRYPT;
 128         int err;
 129         unsigned int num_out = 0, num_in = 0;
 130
 131         /*
 132          * Avoid to do DMA from the stack, switch to using
 133          * dynamically-allocated for the key
 134          */
 135         uint8_t *cipher_key = kmalloc(keylen, GFP_ATOMIC);
 136
 137         if (!cipher_key)
 138                 return -ENOMEM;
 139
 140         memcpy(cipher_key, key, keylen);
 141
 142         spin_lock(&vcrypto->ctrl_lock);
 143         /* Pad ctrl header */
 144         vcrypto->ctrl.header.opcode =
 145                 cpu_to_le32(VIRTIO_CRYPTO_CIPHER_CREATE_SESSION);
 146         vcrypto->ctrl.header.algo = cpu_to_le32(alg);
 147         /* Set the default dataqueue id to 0 */
 148         vcrypto->ctrl.header.queue_id = 0;
 149
 150         vcrypto->input.status = cpu_to_le32(VIRTIO_CRYPTO_ERR);
 151         /* Pad cipher's parameters */
 152         vcrypto->ctrl.u.sym_create_session.op_type =
 153                 cpu_to_le32(VIRTIO_CRYPTO_SYM_OP_CIPHER);
 154         vcrypto->ctrl.u.sym_create_session.u.cipher.para.algo =
 155                 vcrypto->ctrl.header.algo;
 156         vcrypto->ctrl.u.sym_create_session.u.cipher.para.keylen =
 157                 cpu_to_le32(keylen);
 158         vcrypto->ctrl.u.sym_create_session.u.cipher.para.op =
 159                 cpu_to_le32(op);
 160
 161         sg_init_one(&outhdr, &vcrypto->ctrl, sizeof(vcrypto->ctrl));
 162         sgs[num_out++] = &outhdr;
 163
 164         /* Set key */
 165         sg_init_one(&key_sg, cipher_key, keylen);
 166         sgs[num_out++] = &key_sg;
 167
 168         /* Return status and session id back */
 169         sg_init_one(&inhdr, &vcrypto->input, sizeof(vcrypto->input));
 170         sgs[num_out + num_in++] = &inhdr;
 171
 172         err = virtqueue_add_sgs(vcrypto->ctrl_vq, sgs, num_out,
 173                                 num_in, vcrypto, GFP_ATOMIC);
 174         if (err < 0) {
 175                 spin_unlock(&vcrypto->ctrl_lock);
 176                 kzfree(cipher_key);
 177                 return err;
 178         }
 179         virtqueue_kick(vcrypto->ctrl_vq);
 180
 181         /*
 182          * Trapping into the hypervisor, so the request should be
 183          * handled immediately.
 184          */
 185         while (!virtqueue_get_buf(vcrypto->ctrl_vq, &tmp) &&
 186                !virtqueue_is_broken(vcrypto->ctrl_vq))
 187                 cpu_relax();
 188
 189         if (le32_to_cpu(vcrypto->input.status) != VIRTIO_CRYPTO_OK) {
 190                 spin_unlock(&vcrypto->ctrl_lock);
 191                 pr_err("virtio_crypto: Create session failed status: %u\n",
 192                         le32_to_cpu(vcrypto->input.status));
 193                 kzfree(cipher_key);
 194                 return -EINVAL;
 195         }
 196
 197         if (encrypt)
 198                 ctx->enc_sess_info.session_id =
 199                         le64_to_cpu(vcrypto->input.session_id);
 200         else
 201                 ctx->dec_sess_info.session_id =
 202                         le64_to_cpu(vcrypto->input.session_id);
 203
 204         spin_unlock(&vcrypto->ctrl_lock);
 205
 206         kzfree(cipher_key);
 207         return 0;
 208 }
 209
 210 static int virtio_crypto_alg_ablkcipher_close_session(
 211                 struct virtio_crypto_ablkcipher_ctx *ctx,
 212                 int encrypt)
 213 {
 214         struct scatterlist outhdr, status_sg, *sgs[2];
 215         unsigned int tmp;
 216         struct virtio_crypto_destroy_session_req *destroy_session;
 217         struct virtio_crypto *vcrypto = ctx->vcrypto;
 218         int err;
 219         unsigned int num_out = 0, num_in = 0;
 220
 221         spin_lock(&vcrypto->ctrl_lock);
 222         vcrypto->ctrl_status.status = VIRTIO_CRYPTO_ERR;
 223         /* Pad ctrl header */
 224         vcrypto->ctrl.header.opcode =
 225                 cpu_to_le32(VIRTIO_CRYPTO_CIPHER_DESTROY_SESSION);
 226         /* Set the default virtqueue id to 0 */
 227         vcrypto->ctrl.header.queue_id = 0;
 228
 229         destroy_session = &vcrypto->ctrl.u.destroy_session;
 230
 231         if (encrypt)
 232                 destroy_session->session_id =
 233                         cpu_to_le64(ctx->enc_sess_info.session_id);
 234         else
 235                 destroy_session->session_id =
 236                         cpu_to_le64(ctx->dec_sess_info.session_id);
 237
 238         sg_init_one(&outhdr, &vcrypto->ctrl, sizeof(vcrypto->ctrl));
 239         sgs[num_out++] = &outhdr;
 240
 241         /* Return status and session id back */
 242         sg_init_one(&status_sg, &vcrypto->ctrl_status.status,
 243                 sizeof(vcrypto->ctrl_status.status));
 244         sgs[num_out + num_in++] = &status_sg;
 245
 246         err = virtqueue_add_sgs(vcrypto->ctrl_vq, sgs, num_out,
 247                         num_in, vcrypto, GFP_ATOMIC);
 248         if (err < 0) {
 249                 spin_unlock(&vcrypto->ctrl_lock);
 250                 return err;
 251         }
 252         virtqueue_kick(vcrypto->ctrl_vq);
 253
 254         while (!virtqueue_get_buf(vcrypto->ctrl_vq, &tmp) &&
 255                !virtqueue_is_broken(vcrypto->ctrl_vq))
 256                 cpu_relax();
 257
 258         if (vcrypto->ctrl_status.status != VIRTIO_CRYPTO_OK) {
 259                 spin_unlock(&vcrypto->ctrl_lock);
 260                 pr_err("virtio_crypto: Close session failed status: %u, session_id: 0x%llx\n",
 261                         vcrypto->ctrl_status.status,
 262                         destroy_session->session_id);
 263
 264                 return -EINVAL;
 265         }
 266         spin_unlock(&vcrypto->ctrl_lock);
 267
 268         return 0;
 269 }
 270
 271 static int virtio_crypto_alg_ablkcipher_init_sessions(
 272                 struct virtio_crypto_ablkcipher_ctx *ctx,
 273                 const uint8_t *key, unsigned int keylen)
 274 {
 275         uint32_t alg;
 276         int ret;
 277         struct virtio_crypto *vcrypto = ctx->vcrypto;
 278
 279         if (keylen > vcrypto->max_cipher_key_len) {
 280                 pr_err("virtio_crypto: the key is too long\n");
 281                 goto bad_key;
 282         }
 283
 284         if (virtio_crypto_alg_validate_key(keylen, &alg))
 285                 goto bad_key;
 286
 287         /* Create encryption session */
 288         ret = virtio_crypto_alg_ablkcipher_init_session(ctx,
 289                         alg, key, keylen, 1);
 290         if (ret)
 291                 return ret;
 292         /* Create decryption session */
 293         ret = virtio_crypto_alg_ablkcipher_init_session(ctx,
 294                         alg, key, keylen, 0);
 295         if (ret) {
 296                 virtio_crypto_alg_ablkcipher_close_session(ctx, 1);
 297                 return ret;
 298         }
 299         return 0;
 300
 301 bad_key:
 302         crypto_tfm_set_flags(ctx->tfm, CRYPTO_TFM_RES_BAD_KEY_LEN);
 303         return -EINVAL;
 304 }
 305
 306 /* Note: kernel crypto API realization */
 307 static int virtio_crypto_ablkcipher_setkey(struct crypto_ablkcipher *tfm,
 308                                          const uint8_t *key,
 309                                          unsigned int keylen)
 310 {
 311         struct virtio_crypto_ablkcipher_ctx *ctx = crypto_ablkcipher_ctx(tfm);
 312         int ret;
 313
 314         if (!ctx->vcrypto) {
 315                 /* New key */
 316                 int node = virtio_crypto_get_current_node();
 317                 struct virtio_crypto *vcrypto =
 318                                       virtcrypto_get_dev_node(node);
 319                 if (!vcrypto) {
 320                         pr_err("virtio_crypto: Could not find a virtio device in the system");
 321                         return -ENODEV;
 322                 }
 323
 324                 ctx->vcrypto = vcrypto;
 325         } else {
 326                 /* Rekeying, we should close the created sessions previously */
 327                 virtio_crypto_alg_ablkcipher_close_session(ctx, 1);
 328                 virtio_crypto_alg_ablkcipher_close_session(ctx, 0);
 329         }
 330
 331         ret = virtio_crypto_alg_ablkcipher_init_sessions(ctx, key, keylen);
 332         if (ret) {
 333                 virtcrypto_dev_put(ctx->vcrypto);
 334                 ctx->vcrypto = NULL;
 335
 336                 return ret;
 337         }
 338
 339         return 0;
 340 }
 341
 342 static int
 343 __virtio_crypto_ablkcipher_do_req(struct virtio_crypto_sym_request *vc_sym_req,
 344                 struct ablkcipher_request *req,
 345                 struct data_queue *data_vq)
 346 {
 347         struct crypto_ablkcipher *tfm = crypto_ablkcipher_reqtfm(req);
 348         struct virtio_crypto_ablkcipher_ctx *ctx = vc_sym_req->ablkcipher_ctx;
 349         struct virtio_crypto_request *vc_req = &vc_sym_req->base;
 350         unsigned int ivsize = crypto_ablkcipher_ivsize(tfm);
 351         struct virtio_crypto *vcrypto = ctx->vcrypto;
 352         struct virtio_crypto_op_data_req *req_data;
 353         int src_nents, dst_nents;
 354         int err;
 355         unsigned long flags;
 356         struct scatterlist outhdr, iv_sg, status_sg, **sgs;
 357         u64 dst_len;
 358         unsigned int num_out = 0, num_in = 0;
 359         int sg_total;
 360         uint8_t *iv;
 361         struct scatterlist *sg;
 362
 363         src_nents = sg_nents_for_len(req->src, req->nbytes);
 364         if (src_nents < 0) {
 365                 pr_err("Invalid number of src SG.\n");
 366                 return src_nents;
 367         }
 368
 369         dst_nents = sg_nents(req->dst);
 370
 371         pr_debug("virtio_crypto: Number of sgs (src_nents: %d, dst_nents: %d)\n",
 372                         src_nents, dst_nents);
 373
 374         /* Why 3?  outhdr + iv + inhdr */
 375         sg_total = src_nents + dst_nents + 3;
 376         sgs = kzalloc_node(sg_total * sizeof(*sgs), GFP_ATOMIC,
 377                                 dev_to_node(&vcrypto->vdev->dev));
 378         if (!sgs)
 379                 return -ENOMEM;
 380
 381         req_data = kzalloc_node(sizeof(*req_data), GFP_ATOMIC,
 382                                 dev_to_node(&vcrypto->vdev->dev));
 383         if (!req_data) {
 384                 kfree(sgs);
 385                 return -ENOMEM;
 386         }
 387
 388         vc_req->req_data = req_data;
 389         vc_sym_req->type = VIRTIO_CRYPTO_SYM_OP_CIPHER;
 390         /* Head of operation */
 391         if (vc_sym_req->encrypt) {
 392                 req_data->header.session_id =
 393                         cpu_to_le64(ctx->enc_sess_info.session_id);
 394                 req_data->header.opcode =
 395                         cpu_to_le32(VIRTIO_CRYPTO_CIPHER_ENCRYPT);
 396         } else {
 397                 req_data->header.session_id =
 398                         cpu_to_le64(ctx->dec_sess_info.session_id);
 399             req_data->header.opcode =
 400                         cpu_to_le32(VIRTIO_CRYPTO_CIPHER_DECRYPT);
 401         }
 402         req_data->u.sym_req.op_type = cpu_to_le32(VIRTIO_CRYPTO_SYM_OP_CIPHER);
 403         req_data->u.sym_req.u.cipher.para.iv_len = cpu_to_le32(ivsize);
 404         req_data->u.sym_req.u.cipher.para.src_data_len =
 405                         cpu_to_le32(req->nbytes);
 406
 407         dst_len = virtio_crypto_alg_sg_nents_length(req->dst);
 408         if (unlikely(dst_len > U32_MAX)) {
 409                 pr_err("virtio_crypto: The dst_len is beyond U32_MAX\n");
 410                 err = -EINVAL;
 411                 goto free;
 412         }
 413
 414         dst_len = min_t(unsigned int, req->nbytes, dst_len);
 415         pr_debug("virtio_crypto: src_len: %u, dst_len: %llu\n",
 416                         req->nbytes, dst_len);
 417
 418         if (unlikely(req->nbytes + dst_len + ivsize +
 419                 sizeof(vc_req->status) > vcrypto->max_size)) {
 420                 pr_err("virtio_crypto: The length is too big\n");
 421                 err = -EINVAL;
 422                 goto free;
 423         }
 424
 425         req_data->u.sym_req.u.cipher.para.dst_data_len =
 426                         cpu_to_le32((uint32_t)dst_len);
 427
 428         /* Outhdr */
 429         sg_init_one(&outhdr, req_data, sizeof(*req_data));
 430         sgs[num_out++] = &outhdr;
 431
 432         /* IV */
 433
 434         /*
 435          * Avoid to do DMA from the stack, switch to using
 436          * dynamically-allocated for the IV
 437          */
 438         iv = kzalloc_node(ivsize, GFP_ATOMIC,
 439                                 dev_to_node(&vcrypto->vdev->dev));
 440         if (!iv) {
 441                 err = -ENOMEM;
 442                 goto free;
 443         }
 444         memcpy(iv, req->info, ivsize);
 445         sg_init_one(&iv_sg, iv, ivsize);
 446         sgs[num_out++] = &iv_sg;
 447         vc_sym_req->iv = iv;
 448
 449         /* Source data */
 450         for (sg = req->src; src_nents; sg = sg_next(sg), src_nents--)
 451                 sgs[num_out++] = sg;
 452
 453         /* Destination data */
 454         for (sg = req->dst; sg; sg = sg_next(sg))
 455                 sgs[num_out + num_in++] = sg;
 456
 457         /* Status */
 458         sg_init_one(&status_sg, &vc_req->status, sizeof(vc_req->status));
 459         sgs[num_out + num_in++] = &status_sg;
 460
 461         vc_req->sgs = sgs;
 462
 463         spin_lock_irqsave(&data_vq->lock, flags);
 464         err = virtqueue_add_sgs(data_vq->vq, sgs, num_out,
 465                                 num_in, vc_req, GFP_ATOMIC);
 466         virtqueue_kick(data_vq->vq);
 467         spin_unlock_irqrestore(&data_vq->lock, flags);
 468         if (unlikely(err < 0))
 469                 goto free_iv;
 470
 471         return 0;
 472
 473 free_iv:
 474         kzfree(iv);
 475 free:
 476         kzfree(req_data);
 477         kfree(sgs);
 478         return err;
 479 }
 480
 481 static int virtio_crypto_ablkcipher_encrypt(struct ablkcipher_request *req)
 482 {
 483         struct crypto_ablkcipher *atfm = crypto_ablkcipher_reqtfm(req);
 484         struct virtio_crypto_ablkcipher_ctx *ctx = crypto_ablkcipher_ctx(atfm);
 485         struct virtio_crypto_sym_request *vc_sym_req =
 486                                 ablkcipher_request_ctx(req);
 487         struct virtio_crypto_request *vc_req = &vc_sym_req->base;
 488         struct virtio_crypto *vcrypto = ctx->vcrypto;
 489         /* Use the first data virtqueue as default */
 490         struct data_queue *data_vq = &vcrypto->data_vq[0];
 491
 492         if (!req->nbytes)
 493                 return 0;
 494         if (req->nbytes % AES_BLOCK_SIZE)
 495                 return -EINVAL;
 496
 497         vc_req->dataq = data_vq;
 498         vc_req->alg_cb = virtio_crypto_dataq_sym_callback;
 499         vc_sym_req->ablkcipher_ctx = ctx;
 500         vc_sym_req->ablkcipher_req = req;
 501         vc_sym_req->encrypt = true;
 502
 503         return crypto_transfer_cipher_request_to_engine(data_vq->engine, req);
 504 }
 505
 506 static int virtio_crypto_ablkcipher_decrypt(struct ablkcipher_request *req)
 507 {
 508         struct crypto_ablkcipher *atfm = crypto_ablkcipher_reqtfm(req);
 509         struct virtio_crypto_ablkcipher_ctx *ctx = crypto_ablkcipher_ctx(atfm);
 510         struct virtio_crypto_sym_request *vc_sym_req =
 511                                 ablkcipher_request_ctx(req);
 512         struct virtio_crypto_request *vc_req = &vc_sym_req->base;
 513         struct virtio_crypto *vcrypto = ctx->vcrypto;
 514         /* Use the first data virtqueue as default */
 515         struct data_queue *data_vq = &vcrypto->data_vq[0];
 516
 517         if (!req->nbytes)
 518                 return 0;
 519         if (req->nbytes % AES_BLOCK_SIZE)
 520                 return -EINVAL;
 521
 522         vc_req->dataq = data_vq;
 523         vc_req->alg_cb = virtio_crypto_dataq_sym_callback;
 524         vc_sym_req->ablkcipher_ctx = ctx;
 525         vc_sym_req->ablkcipher_req = req;
 526         vc_sym_req->encrypt = false;
 527
 528         return crypto_transfer_cipher_request_to_engine(data_vq->engine, req);
 529 }
 530
 531 static int virtio_crypto_ablkcipher_init(struct crypto_tfm *tfm)
 532 {
 533         struct virtio_crypto_ablkcipher_ctx *ctx = crypto_tfm_ctx(tfm);
 534
 535         tfm->crt_ablkcipher.reqsize = sizeof(struct virtio_crypto_sym_request);
 536         ctx->tfm = tfm;
 537
 538         return 0;
 539 }
 540
 541 static void virtio_crypto_ablkcipher_exit(struct crypto_tfm *tfm)
 542 {
 543         struct virtio_crypto_ablkcipher_ctx *ctx = crypto_tfm_ctx(tfm);
 544
 545         if (!ctx->vcrypto)
 546                 return;
 547
 548         virtio_crypto_alg_ablkcipher_close_session(ctx, 1);
 549         virtio_crypto_alg_ablkcipher_close_session(ctx, 0);
 550         virtcrypto_dev_put(ctx->vcrypto);
 551         ctx->vcrypto = NULL;
 552 }
 553
 554 int virtio_crypto_ablkcipher_crypt_req(
 555         struct crypto_engine *engine,
 556         struct ablkcipher_request *req)
 557 {
 558         struct virtio_crypto_sym_request *vc_sym_req =
 559                                 ablkcipher_request_ctx(req);
 560         struct virtio_crypto_request *vc_req = &vc_sym_req->base;
 561         struct data_queue *data_vq = vc_req->dataq;
 562         int ret;
 563
 564         ret = __virtio_crypto_ablkcipher_do_req(vc_sym_req, req, data_vq);
 565         if (ret < 0)
 566                 return ret;
 567
 568         virtqueue_kick(data_vq->vq);
 569
 570         return 0;
 571 }
 572
 573 static void virtio_crypto_ablkcipher_finalize_req(
 574         struct virtio_crypto_sym_request *vc_sym_req,
 575         struct ablkcipher_request *req,
 576         int err)
 577 {
 578         kzfree(vc_sym_req->iv);
 579         virtcrypto_clear_request(&vc_sym_req->base);
 580
 581         crypto_finalize_cipher_request(vc_sym_req->base.dataq->engine,
 582                                            req, err);
 583 }
 584
 585 static struct crypto_alg virtio_crypto_algs[] = { {
 586         .cra_name = "cbc(aes)",
 587         .cra_driver_name = "virtio_crypto_aes_cbc",
 588         .cra_priority = 150,
 589         .cra_flags = CRYPTO_ALG_TYPE_ABLKCIPHER | CRYPTO_ALG_ASYNC,
 590         .cra_blocksize = AES_BLOCK_SIZE,
 591         .cra_ctxsize  = sizeof(struct virtio_crypto_ablkcipher_ctx),
 592         .cra_alignmask = 0,
 593         .cra_module = THIS_MODULE,
 594         .cra_type = &crypto_ablkcipher_type,
 595         .cra_init = virtio_crypto_ablkcipher_init,
 596         .cra_exit = virtio_crypto_ablkcipher_exit,
 597         .cra_u = {
 598            .ablkcipher = {
 599                         .setkey = virtio_crypto_ablkcipher_setkey,
 600                         .decrypt = virtio_crypto_ablkcipher_decrypt,
 601                         .encrypt = virtio_crypto_ablkcipher_encrypt,
 602                         .min_keysize = AES_MIN_KEY_SIZE,
 603                         .max_keysize = AES_MAX_KEY_SIZE,
 604                         .ivsize = AES_BLOCK_SIZE,
 605                 },
 606         },
 607 } };
 608
 609 int virtio_crypto_algs_register(void)
 610 {
 611         int ret = 0;
 612
 613         mutex_lock(&algs_lock);
 614         if (++virtio_crypto_active_devs != 1)
 615                 goto unlock;
 616
 617         ret = crypto_register_algs(virtio_crypto_algs,
 618                         ARRAY_SIZE(virtio_crypto_algs));
 619         if (ret)
 620                 virtio_crypto_active_devs--;
 621
 622 unlock:
 623         mutex_unlock(&algs_lock);
 624         return ret;
 625 }
 626
 627 void virtio_crypto_algs_unregister(void)
 628 {
 629         mutex_lock(&algs_lock);
 630         if (--virtio_crypto_active_devs != 0)
 631                 goto unlock;
 632
 633         crypto_unregister_algs(virtio_crypto_algs,
 634                         ARRAY_SIZE(virtio_crypto_algs));
 635
 636 unlock:
 637         mutex_unlock(&algs_lock);
 638 }