1// SPDX-License-Identifier: GPL-2.0-or-later
2 /* Algorithms supported by virtio crypto device
3 *
4 * Authors: Gonglei <arei.gonglei@huawei.com>
5 *
6 * Copyright 2016 HUAWEI TECHNOLOGIES CO., LTD.
7 */
8
9#include <crypto/engine.h>
10#include <crypto/internal/skcipher.h>
11#include <crypto/scatterwalk.h>
12#include <linux/err.h>
13#include <linux/scatterlist.h>
14#include <uapi/linux/virtio_crypto.h>
15#include "virtio_crypto_common.h"
16
17
18struct virtio_crypto_skcipher_ctx {
19 struct virtio_crypto *vcrypto;
20
21 struct virtio_crypto_sym_session_info enc_sess_info;
22 struct virtio_crypto_sym_session_info dec_sess_info;
23};
24
25struct virtio_crypto_sym_request {
26 struct virtio_crypto_request base;
27
28 /* Cipher or aead */
29 uint32_t type;
30 uint8_t *iv;
31 /* Encryption? */
32 bool encrypt;
33};
34
35struct virtio_crypto_algo {
36 uint32_t algonum;
37 uint32_t service;
38 unsigned int active_devs;
39 struct skcipher_engine_alg algo;
40};
41
42/*
43 * The algs_lock protects the below global virtio_crypto_active_devs
44 * and crypto algorithms registion.
45 */
46static DEFINE_MUTEX(algs_lock);
47static void virtio_crypto_skcipher_finalize_req(
48 struct virtio_crypto_sym_request *vc_sym_req,
49 struct skcipher_request *req,
50 int err);
51
52static void virtio_crypto_dataq_sym_callback
53 (struct virtio_crypto_request *vc_req, int len)
54{
55 struct virtio_crypto_sym_request *vc_sym_req =
56 container_of(vc_req, struct virtio_crypto_sym_request, base);
57 struct skcipher_request *ablk_req =
58 container_of((void *)vc_sym_req, struct skcipher_request,
59 __ctx);
60 int error;
61
62 /* Finish the encrypt or decrypt process */
63 if (vc_sym_req->type == VIRTIO_CRYPTO_SYM_OP_CIPHER) {
64 switch (vc_req->status) {
65 case VIRTIO_CRYPTO_OK:
66 error = 0;
67 break;
68 case VIRTIO_CRYPTO_INVSESS:
69 case VIRTIO_CRYPTO_ERR:
70 error = -EINVAL;
71 break;
72 case VIRTIO_CRYPTO_BADMSG:
73 error = -EBADMSG;
74 break;
75 default:
76 error = -EIO;
77 break;
78 }
79 virtio_crypto_skcipher_finalize_req(vc_sym_req,
80 req: ablk_req, err: error);
81 }
82}
83
84static u64 virtio_crypto_alg_sg_nents_length(struct scatterlist *sg)
85{
86 u64 total = 0;
87
88 for (total = 0; sg; sg = sg_next(sg))
89 total += sg->length;
90
91 return total;
92}
93
94static int
95virtio_crypto_alg_validate_key(int key_len, uint32_t *alg)
96{
97 switch (key_len) {
98 case AES_KEYSIZE_128:
99 case AES_KEYSIZE_192:
100 case AES_KEYSIZE_256:
101 *alg = VIRTIO_CRYPTO_CIPHER_AES_CBC;
102 break;
103 default:
104 return -EINVAL;
105 }
106 return 0;
107}
108
109static int virtio_crypto_alg_skcipher_init_session(
110 struct virtio_crypto_skcipher_ctx *ctx,
111 uint32_t alg, const uint8_t *key,
112 unsigned int keylen,
113 int encrypt)
114{
115 struct scatterlist outhdr, key_sg, inhdr, *sgs[3];
116 struct virtio_crypto *vcrypto = ctx->vcrypto;
117 int op = encrypt ? VIRTIO_CRYPTO_OP_ENCRYPT : VIRTIO_CRYPTO_OP_DECRYPT;
118 int err;
119 unsigned int num_out = 0, num_in = 0;
120 struct virtio_crypto_op_ctrl_req *ctrl;
121 struct virtio_crypto_session_input *input;
122 struct virtio_crypto_sym_create_session_req *sym_create_session;
123 struct virtio_crypto_ctrl_request *vc_ctrl_req;
124
125 /*
126 * Avoid to do DMA from the stack, switch to using
127 * dynamically-allocated for the key
128 */
129 uint8_t *cipher_key = kmemdup(key, keylen, GFP_ATOMIC);
130
131 if (!cipher_key)
132 return -ENOMEM;
133
134 vc_ctrl_req = kzalloc(sizeof(*vc_ctrl_req), GFP_KERNEL);
135 if (!vc_ctrl_req) {
136 err = -ENOMEM;
137 goto out;
138 }
139
140 /* Pad ctrl header */
141 ctrl = &vc_ctrl_req->ctrl;
142 ctrl->header.opcode = cpu_to_le32(VIRTIO_CRYPTO_CIPHER_CREATE_SESSION);
143 ctrl->header.algo = cpu_to_le32(alg);
144 /* Set the default dataqueue id to 0 */
145 ctrl->header.queue_id = 0;
146
147 input = &vc_ctrl_req->input;
148 input->status = cpu_to_le32(VIRTIO_CRYPTO_ERR);
149 /* Pad cipher's parameters */
150 sym_create_session = &ctrl->u.sym_create_session;
151 sym_create_session->op_type = cpu_to_le32(VIRTIO_CRYPTO_SYM_OP_CIPHER);
152 sym_create_session->u.cipher.para.algo = ctrl->header.algo;
153 sym_create_session->u.cipher.para.keylen = cpu_to_le32(keylen);
154 sym_create_session->u.cipher.para.op = cpu_to_le32(op);
155
156 sg_init_one(&outhdr, ctrl, sizeof(*ctrl));
157 sgs[num_out++] = &outhdr;
158
159 /* Set key */
160 sg_init_one(&key_sg, cipher_key, keylen);
161 sgs[num_out++] = &key_sg;
162
163 /* Return status and session id back */
164 sg_init_one(&inhdr, input, sizeof(*input));
165 sgs[num_out + num_in++] = &inhdr;
166
167 err = virtio_crypto_ctrl_vq_request(vcrypto, sgs, out_sgs: num_out, in_sgs: num_in, vc_ctrl_req);
168 if (err < 0)
169 goto out;
170
171 if (le32_to_cpu(input->status) != VIRTIO_CRYPTO_OK) {
172 pr_err("virtio_crypto: Create session failed status: %u\n",
173 le32_to_cpu(input->status));
174 err = -EINVAL;
175 goto out;
176 }
177
178 if (encrypt)
179 ctx->enc_sess_info.session_id = le64_to_cpu(input->session_id);
180 else
181 ctx->dec_sess_info.session_id = le64_to_cpu(input->session_id);
182
183 err = 0;
184out:
185 kfree(objp: vc_ctrl_req);
186 kfree_sensitive(objp: cipher_key);
187 return err;
188}
189
190static int virtio_crypto_alg_skcipher_close_session(
191 struct virtio_crypto_skcipher_ctx *ctx,
192 int encrypt)
193{
194 struct scatterlist outhdr, status_sg, *sgs[2];
195 struct virtio_crypto_destroy_session_req *destroy_session;
196 struct virtio_crypto *vcrypto = ctx->vcrypto;
197 int err;
198 unsigned int num_out = 0, num_in = 0;
199 struct virtio_crypto_op_ctrl_req *ctrl;
200 struct virtio_crypto_inhdr *ctrl_status;
201 struct virtio_crypto_ctrl_request *vc_ctrl_req;
202
203 vc_ctrl_req = kzalloc(sizeof(*vc_ctrl_req), GFP_KERNEL);
204 if (!vc_ctrl_req)
205 return -ENOMEM;
206
207 ctrl_status = &vc_ctrl_req->ctrl_status;
208 ctrl_status->status = VIRTIO_CRYPTO_ERR;
209 /* Pad ctrl header */
210 ctrl = &vc_ctrl_req->ctrl;
211 ctrl->header.opcode = cpu_to_le32(VIRTIO_CRYPTO_CIPHER_DESTROY_SESSION);
212 /* Set the default virtqueue id to 0 */
213 ctrl->header.queue_id = 0;
214
215 destroy_session = &ctrl->u.destroy_session;
216
217 if (encrypt)
218 destroy_session->session_id = cpu_to_le64(ctx->enc_sess_info.session_id);
219 else
220 destroy_session->session_id = cpu_to_le64(ctx->dec_sess_info.session_id);
221
222 sg_init_one(&outhdr, ctrl, sizeof(*ctrl));
223 sgs[num_out++] = &outhdr;
224
225 /* Return status and session id back */
226 sg_init_one(&status_sg, &ctrl_status->status, sizeof(ctrl_status->status));
227 sgs[num_out + num_in++] = &status_sg;
228
229 err = virtio_crypto_ctrl_vq_request(vcrypto, sgs, out_sgs: num_out, in_sgs: num_in, vc_ctrl_req);
230 if (err < 0)
231 goto out;
232
233 if (ctrl_status->status != VIRTIO_CRYPTO_OK) {
234 pr_err("virtio_crypto: Close session failed status: %u, session_id: 0x%llx\n",
235 ctrl_status->status, destroy_session->session_id);
236
237 err = -EINVAL;
238 goto out;
239 }
240
241 err = 0;
242out:
243 kfree(objp: vc_ctrl_req);
244 return err;
245}
246
247static int virtio_crypto_alg_skcipher_init_sessions(
248 struct virtio_crypto_skcipher_ctx *ctx,
249 const uint8_t *key, unsigned int keylen)
250{
251 uint32_t alg;
252 int ret;
253 struct virtio_crypto *vcrypto = ctx->vcrypto;
254
255 if (keylen > vcrypto->max_cipher_key_len) {
256 pr_err("virtio_crypto: the key is too long\n");
257 return -EINVAL;
258 }
259
260 if (virtio_crypto_alg_validate_key(key_len: keylen, alg: &alg))
261 return -EINVAL;
262
263 /* Create encryption session */
264 ret = virtio_crypto_alg_skcipher_init_session(ctx,
265 alg, key, keylen, encrypt: 1);
266 if (ret)
267 return ret;
268 /* Create decryption session */
269 ret = virtio_crypto_alg_skcipher_init_session(ctx,
270 alg, key, keylen, encrypt: 0);
271 if (ret) {
272 virtio_crypto_alg_skcipher_close_session(ctx, encrypt: 1);
273 return ret;
274 }
275 return 0;
276}
277
278/* Note: kernel crypto API realization */
279static int virtio_crypto_skcipher_setkey(struct crypto_skcipher *tfm,
280 const uint8_t *key,
281 unsigned int keylen)
282{
283 struct virtio_crypto_skcipher_ctx *ctx = crypto_skcipher_ctx(tfm);
284 uint32_t alg;
285 int ret;
286
287 ret = virtio_crypto_alg_validate_key(key_len: keylen, alg: &alg);
288 if (ret)
289 return ret;
290
291 if (!ctx->vcrypto) {
292 /* New key */
293 int node = virtio_crypto_get_current_node();
294 struct virtio_crypto *vcrypto =
295 virtcrypto_get_dev_node(node,
296 VIRTIO_CRYPTO_SERVICE_CIPHER, algo: alg);
297 if (!vcrypto) {
298 pr_err("virtio_crypto: Could not find a virtio device in the system or unsupported algo\n");
299 return -ENODEV;
300 }
301
302 ctx->vcrypto = vcrypto;
303 } else {
304 /* Rekeying, we should close the created sessions previously */
305 virtio_crypto_alg_skcipher_close_session(ctx, encrypt: 1);
306 virtio_crypto_alg_skcipher_close_session(ctx, encrypt: 0);
307 }
308
309 ret = virtio_crypto_alg_skcipher_init_sessions(ctx, key, keylen);
310 if (ret) {
311 virtcrypto_dev_put(vcrypto_dev: ctx->vcrypto);
312 ctx->vcrypto = NULL;
313
314 return ret;
315 }
316
317 return 0;
318}
319
320static int
321__virtio_crypto_skcipher_do_req(struct virtio_crypto_sym_request *vc_sym_req,
322 struct skcipher_request *req,
323 struct data_queue *data_vq)
324{
325 struct crypto_skcipher *tfm = crypto_skcipher_reqtfm(req);
326 struct virtio_crypto_skcipher_ctx *ctx = crypto_skcipher_ctx(tfm);
327 struct virtio_crypto_request *vc_req = &vc_sym_req->base;
328 unsigned int ivsize = crypto_skcipher_ivsize(tfm);
329 struct virtio_crypto *vcrypto = ctx->vcrypto;
330 struct virtio_crypto_op_data_req *req_data;
331 int src_nents, dst_nents;
332 int err;
333 unsigned long flags;
334 struct scatterlist outhdr, iv_sg, status_sg, **sgs;
335 u64 dst_len;
336 unsigned int num_out = 0, num_in = 0;
337 int sg_total;
338 uint8_t *iv;
339 struct scatterlist *sg;
340
341 src_nents = sg_nents_for_len(sg: req->src, len: req->cryptlen);
342 if (src_nents < 0) {
343 pr_err("Invalid number of src SG.\n");
344 return src_nents;
345 }
346
347 dst_nents = sg_nents(sg: req->dst);
348
349 pr_debug("virtio_crypto: Number of sgs (src_nents: %d, dst_nents: %d)\n",
350 src_nents, dst_nents);
351
352 /* Why 3? outhdr + iv + inhdr */
353 sg_total = src_nents + dst_nents + 3;
354 sgs = kcalloc_node(sg_total, sizeof(*sgs), GFP_KERNEL,
355 dev_to_node(&vcrypto->vdev->dev));
356 if (!sgs)
357 return -ENOMEM;
358
359 req_data = kzalloc_node(sizeof(*req_data), GFP_KERNEL,
360 dev_to_node(&vcrypto->vdev->dev));
361 if (!req_data) {
362 kfree(objp: sgs);
363 return -ENOMEM;
364 }
365
366 vc_req->req_data = req_data;
367 vc_sym_req->type = VIRTIO_CRYPTO_SYM_OP_CIPHER;
368 /* Head of operation */
369 if (vc_sym_req->encrypt) {
370 req_data->header.session_id =
371 cpu_to_le64(ctx->enc_sess_info.session_id);
372 req_data->header.opcode =
373 cpu_to_le32(VIRTIO_CRYPTO_CIPHER_ENCRYPT);
374 } else {
375 req_data->header.session_id =
376 cpu_to_le64(ctx->dec_sess_info.session_id);
377 req_data->header.opcode =
378 cpu_to_le32(VIRTIO_CRYPTO_CIPHER_DECRYPT);
379 }
380 req_data->u.sym_req.op_type = cpu_to_le32(VIRTIO_CRYPTO_SYM_OP_CIPHER);
381 req_data->u.sym_req.u.cipher.para.iv_len = cpu_to_le32(ivsize);
382 req_data->u.sym_req.u.cipher.para.src_data_len =
383 cpu_to_le32(req->cryptlen);
384
385 dst_len = virtio_crypto_alg_sg_nents_length(sg: req->dst);
386 if (unlikely(dst_len > U32_MAX)) {
387 pr_err("virtio_crypto: The dst_len is beyond U32_MAX\n");
388 err = -EINVAL;
389 goto free;
390 }
391
392 dst_len = min_t(unsigned int, req->cryptlen, dst_len);
393 pr_debug("virtio_crypto: src_len: %u, dst_len: %llu\n",
394 req->cryptlen, dst_len);
395
396 if (unlikely(req->cryptlen + dst_len + ivsize +
397 sizeof(vc_req->status) > vcrypto->max_size)) {
398 pr_err("virtio_crypto: The length is too big\n");
399 err = -EINVAL;
400 goto free;
401 }
402
403 req_data->u.sym_req.u.cipher.para.dst_data_len =
404 cpu_to_le32((uint32_t)dst_len);
405
406 /* Outhdr */
407 sg_init_one(&outhdr, req_data, sizeof(*req_data));
408 sgs[num_out++] = &outhdr;
409
410 /* IV */
411
412 /*
413 * Avoid to do DMA from the stack, switch to using
414 * dynamically-allocated for the IV
415 */
416 iv = kzalloc_node(ivsize, GFP_ATOMIC,
417 dev_to_node(&vcrypto->vdev->dev));
418 if (!iv) {
419 err = -ENOMEM;
420 goto free;
421 }
422 memcpy(iv, req->iv, ivsize);
423 if (!vc_sym_req->encrypt)
424 scatterwalk_map_and_copy(buf: req->iv, sg: req->src,
425 start: req->cryptlen - AES_BLOCK_SIZE,
426 AES_BLOCK_SIZE, out: 0);
427
428 sg_init_one(&iv_sg, iv, ivsize);
429 sgs[num_out++] = &iv_sg;
430 vc_sym_req->iv = iv;
431
432 /* Source data */
433 for (sg = req->src; src_nents; sg = sg_next(sg), src_nents--)
434 sgs[num_out++] = sg;
435
436 /* Destination data */
437 for (sg = req->dst; sg; sg = sg_next(sg))
438 sgs[num_out + num_in++] = sg;
439
440 /* Status */
441 sg_init_one(&status_sg, &vc_req->status, sizeof(vc_req->status));
442 sgs[num_out + num_in++] = &status_sg;
443
444 vc_req->sgs = sgs;
445
446 spin_lock_irqsave(&data_vq->lock, flags);
447 err = virtqueue_add_sgs(vq: data_vq->vq, sgs, out_sgs: num_out,
448 in_sgs: num_in, data: vc_req, GFP_ATOMIC);
449 virtqueue_kick(vq: data_vq->vq);
450 spin_unlock_irqrestore(lock: &data_vq->lock, flags);
451 if (unlikely(err < 0))
452 goto free_iv;
453
454 return 0;
455
456free_iv:
457 kfree_sensitive(objp: iv);
458free:
459 kfree_sensitive(objp: req_data);
460 kfree(objp: sgs);
461 return err;
462}
463
464static int virtio_crypto_skcipher_encrypt(struct skcipher_request *req)
465{
466 struct crypto_skcipher *atfm = crypto_skcipher_reqtfm(req);
467 struct virtio_crypto_skcipher_ctx *ctx = crypto_skcipher_ctx(tfm: atfm);
468 struct virtio_crypto_sym_request *vc_sym_req =
469 skcipher_request_ctx(req);
470 struct virtio_crypto_request *vc_req = &vc_sym_req->base;
471 struct virtio_crypto *vcrypto = ctx->vcrypto;
472 /* Use the first data virtqueue as default */
473 struct data_queue *data_vq = &vcrypto->data_vq[0];
474
475 if (!req->cryptlen)
476 return 0;
477 if (req->cryptlen % AES_BLOCK_SIZE)
478 return -EINVAL;
479
480 vc_req->dataq = data_vq;
481 vc_req->alg_cb = virtio_crypto_dataq_sym_callback;
482 vc_sym_req->encrypt = true;
483
484 return crypto_transfer_skcipher_request_to_engine(engine: data_vq->engine, req);
485}
486
487static int virtio_crypto_skcipher_decrypt(struct skcipher_request *req)
488{
489 struct crypto_skcipher *atfm = crypto_skcipher_reqtfm(req);
490 struct virtio_crypto_skcipher_ctx *ctx = crypto_skcipher_ctx(tfm: atfm);
491 struct virtio_crypto_sym_request *vc_sym_req =
492 skcipher_request_ctx(req);
493 struct virtio_crypto_request *vc_req = &vc_sym_req->base;
494 struct virtio_crypto *vcrypto = ctx->vcrypto;
495 /* Use the first data virtqueue as default */
496 struct data_queue *data_vq = &vcrypto->data_vq[0];
497
498 if (!req->cryptlen)
499 return 0;
500 if (req->cryptlen % AES_BLOCK_SIZE)
501 return -EINVAL;
502
503 vc_req->dataq = data_vq;
504 vc_req->alg_cb = virtio_crypto_dataq_sym_callback;
505 vc_sym_req->encrypt = false;
506
507 return crypto_transfer_skcipher_request_to_engine(engine: data_vq->engine, req);
508}
509
510static int virtio_crypto_skcipher_init(struct crypto_skcipher *tfm)
511{
512 crypto_skcipher_set_reqsize(skcipher: tfm, reqsize: sizeof(struct virtio_crypto_sym_request));
513
514 return 0;
515}
516
517static void virtio_crypto_skcipher_exit(struct crypto_skcipher *tfm)
518{
519 struct virtio_crypto_skcipher_ctx *ctx = crypto_skcipher_ctx(tfm);
520
521 if (!ctx->vcrypto)
522 return;
523
524 virtio_crypto_alg_skcipher_close_session(ctx, encrypt: 1);
525 virtio_crypto_alg_skcipher_close_session(ctx, encrypt: 0);
526 virtcrypto_dev_put(vcrypto_dev: ctx->vcrypto);
527 ctx->vcrypto = NULL;
528}
529
530int virtio_crypto_skcipher_crypt_req(
531 struct crypto_engine *engine, void *vreq)
532{
533 struct skcipher_request *req = container_of(vreq, struct skcipher_request, base);
534 struct virtio_crypto_sym_request *vc_sym_req =
535 skcipher_request_ctx(req);
536 struct virtio_crypto_request *vc_req = &vc_sym_req->base;
537 struct data_queue *data_vq = vc_req->dataq;
538 int ret;
539
540 ret = __virtio_crypto_skcipher_do_req(vc_sym_req, req, data_vq);
541 if (ret < 0)
542 return ret;
543
544 virtqueue_kick(vq: data_vq->vq);
545
546 return 0;
547}
548
549static void virtio_crypto_skcipher_finalize_req(
550 struct virtio_crypto_sym_request *vc_sym_req,
551 struct skcipher_request *req,
552 int err)
553{
554 if (vc_sym_req->encrypt)
555 scatterwalk_map_and_copy(buf: req->iv, sg: req->dst,
556 start: req->cryptlen - AES_BLOCK_SIZE,
557 AES_BLOCK_SIZE, out: 0);
558 kfree_sensitive(objp: vc_sym_req->iv);
559 virtcrypto_clear_request(vc_req: &vc_sym_req->base);
560
561 crypto_finalize_skcipher_request(engine: vc_sym_req->base.dataq->engine,
562 req, err);
563}
564
565static struct virtio_crypto_algo virtio_crypto_algs[] = { {
566 .algonum = VIRTIO_CRYPTO_CIPHER_AES_CBC,
567 .service = VIRTIO_CRYPTO_SERVICE_CIPHER,
568 .algo.base = {
569 .base.cra_name = "cbc(aes)",
570 .base.cra_driver_name = "virtio_crypto_aes_cbc",
571 .base.cra_priority = 150,
572 .base.cra_flags = CRYPTO_ALG_ASYNC |
573 CRYPTO_ALG_ALLOCATES_MEMORY,
574 .base.cra_blocksize = AES_BLOCK_SIZE,
575 .base.cra_ctxsize = sizeof(struct virtio_crypto_skcipher_ctx),
576 .base.cra_module = THIS_MODULE,
577 .init = virtio_crypto_skcipher_init,
578 .exit = virtio_crypto_skcipher_exit,
579 .setkey = virtio_crypto_skcipher_setkey,
580 .decrypt = virtio_crypto_skcipher_decrypt,
581 .encrypt = virtio_crypto_skcipher_encrypt,
582 .min_keysize = AES_MIN_KEY_SIZE,
583 .max_keysize = AES_MAX_KEY_SIZE,
584 .ivsize = AES_BLOCK_SIZE,
585 },
586 .algo.op = {
587 .do_one_request = virtio_crypto_skcipher_crypt_req,
588 },
589} };
590
591int virtio_crypto_skcipher_algs_register(struct virtio_crypto *vcrypto)
592{
593 int ret = 0;
594 int i = 0;
595
596 mutex_lock(&algs_lock);
597
598 for (i = 0; i < ARRAY_SIZE(virtio_crypto_algs); i++) {
599
600 uint32_t service = virtio_crypto_algs[i].service;
601 uint32_t algonum = virtio_crypto_algs[i].algonum;
602
603 if (!virtcrypto_algo_is_supported(vcrypto_dev: vcrypto, service, algo: algonum))
604 continue;
605
606 if (virtio_crypto_algs[i].active_devs == 0) {
607 ret = crypto_engine_register_skcipher(alg: &virtio_crypto_algs[i].algo);
608 if (ret)
609 goto unlock;
610 }
611
612 virtio_crypto_algs[i].active_devs++;
613 dev_info(&vcrypto->vdev->dev, "Registered algo %s\n",
614 virtio_crypto_algs[i].algo.base.base.cra_name);
615 }
616
617unlock:
618 mutex_unlock(lock: &algs_lock);
619 return ret;
620}
621
622void virtio_crypto_skcipher_algs_unregister(struct virtio_crypto *vcrypto)
623{
624 int i = 0;
625
626 mutex_lock(&algs_lock);
627
628 for (i = 0; i < ARRAY_SIZE(virtio_crypto_algs); i++) {
629
630 uint32_t service = virtio_crypto_algs[i].service;
631 uint32_t algonum = virtio_crypto_algs[i].algonum;
632
633 if (virtio_crypto_algs[i].active_devs == 0 ||
634 !virtcrypto_algo_is_supported(vcrypto_dev: vcrypto, service, algo: algonum))
635 continue;
636
637 if (virtio_crypto_algs[i].active_devs == 1)
638 crypto_engine_unregister_skcipher(alg: &virtio_crypto_algs[i].algo);
639
640 virtio_crypto_algs[i].active_devs--;
641 }
642
643 mutex_unlock(lock: &algs_lock);
644}
645

source code of linux/drivers/crypto/virtio/virtio_crypto_skcipher_algs.c