xref: /openbmc/linux/drivers/crypto/virtio/virtio_crypto_core.c (revision b240b419db5d624ce7a5a397d6f62a1a686009ec) 
1  /* Driver for Virtio crypto device.
2   *
3   * Copyright 2016 HUAWEI TECHNOLOGIES CO., LTD.
4   *
5   * This program is free software; you can redistribute it and/or modify
6   * it under the terms of the GNU General Public License as published by
7   * the Free Software Foundation; either version 2 of the License, or
8   * (at your option) any later version.
9   *
10   * This program is distributed in the hope that it will be useful,
11   * but WITHOUT ANY WARRANTY; without even the implied warranty of
12   * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
13   * GNU General Public License for more details.
14   *
15   * You should have received a copy of the GNU General Public License
16   * along with this program; if not, see <http://www.gnu.org/licenses/>.
17   */
18 
19 #include <linux/err.h>
20 #include <linux/module.h>
21 #include <linux/virtio_config.h>
22 #include <linux/cpu.h>
23 
24 #include <uapi/linux/virtio_crypto.h>
25 #include "virtio_crypto_common.h"
26 
27 
28 void
29 virtcrypto_clear_request(struct virtio_crypto_request *vc_req)
30 {
31 	if (vc_req) {
32 		kzfree(vc_req->req_data);
33 		kfree(vc_req->sgs);
34 	}
35 }
36 
37 static void virtcrypto_dataq_callback(struct virtqueue *vq)
38 {
39 	struct virtio_crypto *vcrypto = vq->vdev->priv;
40 	struct virtio_crypto_request *vc_req;
41 	unsigned long flags;
42 	unsigned int len;
43 	unsigned int qid = vq->index;
44 
45 	spin_lock_irqsave(&vcrypto->data_vq[qid].lock, flags);
46 	do {
47 		virtqueue_disable_cb(vq);
48 		while ((vc_req = virtqueue_get_buf(vq, &len)) != NULL) {
49 			spin_unlock_irqrestore(
50 				&vcrypto->data_vq[qid].lock, flags);
51 			if (vc_req->alg_cb)
52 				vc_req->alg_cb(vc_req, len);
53 			spin_lock_irqsave(
54 				&vcrypto->data_vq[qid].lock, flags);
55 		}
56 	} while (!virtqueue_enable_cb(vq));
57 	spin_unlock_irqrestore(&vcrypto->data_vq[qid].lock, flags);
58 }
59 
60 static int virtcrypto_find_vqs(struct virtio_crypto *vi)
61 {
62 	vq_callback_t **callbacks;
63 	struct virtqueue **vqs;
64 	int ret = -ENOMEM;
65 	int i, total_vqs;
66 	const char **names;
67 	struct device *dev = &vi->vdev->dev;
68 
69 	/*
70 	 * We expect 1 data virtqueue, followed by
71 	 * possible N-1 data queues used in multiqueue mode,
72 	 * followed by control vq.
73 	 */
74 	total_vqs = vi->max_data_queues + 1;
75 
76 	/* Allocate space for find_vqs parameters */
77 	vqs = kcalloc(total_vqs, sizeof(*vqs), GFP_KERNEL);
78 	if (!vqs)
79 		goto err_vq;
80 	callbacks = kcalloc(total_vqs, sizeof(*callbacks), GFP_KERNEL);
81 	if (!callbacks)
82 		goto err_callback;
83 	names = kcalloc(total_vqs, sizeof(*names), GFP_KERNEL);
84 	if (!names)
85 		goto err_names;
86 
87 	/* Parameters for control virtqueue */
88 	callbacks[total_vqs - 1] = NULL;
89 	names[total_vqs - 1] = "controlq";
90 
91 	/* Allocate/initialize parameters for data virtqueues */
92 	for (i = 0; i < vi->max_data_queues; i++) {
93 		callbacks[i] = virtcrypto_dataq_callback;
94 		snprintf(vi->data_vq[i].name, sizeof(vi->data_vq[i].name),
95 				"dataq.%d", i);
96 		names[i] = vi->data_vq[i].name;
97 	}
98 
99 	ret = virtio_find_vqs(vi->vdev, total_vqs, vqs, callbacks, names, NULL);
100 	if (ret)
101 		goto err_find;
102 
103 	vi->ctrl_vq = vqs[total_vqs - 1];
104 
105 	for (i = 0; i < vi->max_data_queues; i++) {
106 		spin_lock_init(&vi->data_vq[i].lock);
107 		vi->data_vq[i].vq = vqs[i];
108 		/* Initialize crypto engine */
109 		vi->data_vq[i].engine = crypto_engine_alloc_init(dev, 1);
110 		if (!vi->data_vq[i].engine) {
111 			ret = -ENOMEM;
112 			goto err_engine;
113 		}
114 	}
115 
116 	kfree(names);
117 	kfree(callbacks);
118 	kfree(vqs);
119 
120 	return 0;
121 
122 err_engine:
123 err_find:
124 	kfree(names);
125 err_names:
126 	kfree(callbacks);
127 err_callback:
128 	kfree(vqs);
129 err_vq:
130 	return ret;
131 }
132 
133 static int virtcrypto_alloc_queues(struct virtio_crypto *vi)
134 {
135 	vi->data_vq = kcalloc(vi->max_data_queues, sizeof(*vi->data_vq),
136 				GFP_KERNEL);
137 	if (!vi->data_vq)
138 		return -ENOMEM;
139 
140 	return 0;
141 }
142 
143 static void virtcrypto_clean_affinity(struct virtio_crypto *vi, long hcpu)
144 {
145 	int i;
146 
147 	if (vi->affinity_hint_set) {
148 		for (i = 0; i < vi->max_data_queues; i++)
149 			virtqueue_set_affinity(vi->data_vq[i].vq, -1);
150 
151 		vi->affinity_hint_set = false;
152 	}
153 }
154 
155 static void virtcrypto_set_affinity(struct virtio_crypto *vcrypto)
156 {
157 	int i = 0;
158 	int cpu;
159 
160 	/*
161 	 * In single queue mode, we don't set the cpu affinity.
162 	 */
163 	if (vcrypto->curr_queue == 1 || vcrypto->max_data_queues == 1) {
164 		virtcrypto_clean_affinity(vcrypto, -1);
165 		return;
166 	}
167 
168 	/*
169 	 * In multiqueue mode, we let the queue to be private to one cpu
170 	 * by setting the affinity hint to eliminate the contention.
171 	 *
172 	 * TODO: adds cpu hotplug support by register cpu notifier.
173 	 *
174 	 */
175 	for_each_online_cpu(cpu) {
176 		virtqueue_set_affinity(vcrypto->data_vq[i].vq, cpu);
177 		if (++i >= vcrypto->max_data_queues)
178 			break;
179 	}
180 
181 	vcrypto->affinity_hint_set = true;
182 }
183 
184 static void virtcrypto_free_queues(struct virtio_crypto *vi)
185 {
186 	kfree(vi->data_vq);
187 }
188 
189 static int virtcrypto_init_vqs(struct virtio_crypto *vi)
190 {
191 	int ret;
192 
193 	/* Allocate send & receive queues */
194 	ret = virtcrypto_alloc_queues(vi);
195 	if (ret)
196 		goto err;
197 
198 	ret = virtcrypto_find_vqs(vi);
199 	if (ret)
200 		goto err_free;
201 
202 	get_online_cpus();
203 	virtcrypto_set_affinity(vi);
204 	put_online_cpus();
205 
206 	return 0;
207 
208 err_free:
209 	virtcrypto_free_queues(vi);
210 err:
211 	return ret;
212 }
213 
214 static int virtcrypto_update_status(struct virtio_crypto *vcrypto)
215 {
216 	u32 status;
217 	int err;
218 
219 	virtio_cread(vcrypto->vdev,
220 	    struct virtio_crypto_config, status, &status);
221 
222 	/*
223 	 * Unknown status bits would be a host error and the driver
224 	 * should consider the device to be broken.
225 	 */
226 	if (status & (~VIRTIO_CRYPTO_S_HW_READY)) {
227 		dev_warn(&vcrypto->vdev->dev,
228 				"Unknown status bits: 0x%x\n", status);
229 
230 		virtio_break_device(vcrypto->vdev);
231 		return -EPERM;
232 	}
233 
234 	if (vcrypto->status == status)
235 		return 0;
236 
237 	vcrypto->status = status;
238 
239 	if (vcrypto->status & VIRTIO_CRYPTO_S_HW_READY) {
240 		err = virtcrypto_dev_start(vcrypto);
241 		if (err) {
242 			dev_err(&vcrypto->vdev->dev,
243 				"Failed to start virtio crypto device.\n");
244 
245 			return -EPERM;
246 		}
247 		dev_info(&vcrypto->vdev->dev, "Accelerator device is ready\n");
248 	} else {
249 		virtcrypto_dev_stop(vcrypto);
250 		dev_info(&vcrypto->vdev->dev, "Accelerator is not ready\n");
251 	}
252 
253 	return 0;
254 }
255 
256 static int virtcrypto_start_crypto_engines(struct virtio_crypto *vcrypto)
257 {
258 	int32_t i;
259 	int ret;
260 
261 	for (i = 0; i < vcrypto->max_data_queues; i++) {
262 		if (vcrypto->data_vq[i].engine) {
263 			ret = crypto_engine_start(vcrypto->data_vq[i].engine);
264 			if (ret)
265 				goto err;
266 		}
267 	}
268 
269 	return 0;
270 
271 err:
272 	while (--i >= 0)
273 		if (vcrypto->data_vq[i].engine)
274 			crypto_engine_exit(vcrypto->data_vq[i].engine);
275 
276 	return ret;
277 }
278 
279 static void virtcrypto_clear_crypto_engines(struct virtio_crypto *vcrypto)
280 {
281 	u32 i;
282 
283 	for (i = 0; i < vcrypto->max_data_queues; i++)
284 		if (vcrypto->data_vq[i].engine)
285 			crypto_engine_exit(vcrypto->data_vq[i].engine);
286 }
287 
288 static void virtcrypto_del_vqs(struct virtio_crypto *vcrypto)
289 {
290 	struct virtio_device *vdev = vcrypto->vdev;
291 
292 	virtcrypto_clean_affinity(vcrypto, -1);
293 
294 	vdev->config->del_vqs(vdev);
295 
296 	virtcrypto_free_queues(vcrypto);
297 }
298 
299 static int virtcrypto_probe(struct virtio_device *vdev)
300 {
301 	int err = -EFAULT;
302 	struct virtio_crypto *vcrypto;
303 	u32 max_data_queues = 0, max_cipher_key_len = 0;
304 	u32 max_auth_key_len = 0;
305 	u64 max_size = 0;
306 
307 	if (!virtio_has_feature(vdev, VIRTIO_F_VERSION_1))
308 		return -ENODEV;
309 
310 	if (!vdev->config->get) {
311 		dev_err(&vdev->dev, "%s failure: config access disabled\n",
312 			__func__);
313 		return -EINVAL;
314 	}
315 
316 	if (num_possible_nodes() > 1 && dev_to_node(&vdev->dev) < 0) {
317 		/*
318 		 * If the accelerator is connected to a node with no memory
319 		 * there is no point in using the accelerator since the remote
320 		 * memory transaction will be very slow.
321 		 */
322 		dev_err(&vdev->dev, "Invalid NUMA configuration.\n");
323 		return -EINVAL;
324 	}
325 
326 	vcrypto = kzalloc_node(sizeof(*vcrypto), GFP_KERNEL,
327 					dev_to_node(&vdev->dev));
328 	if (!vcrypto)
329 		return -ENOMEM;
330 
331 	virtio_cread(vdev, struct virtio_crypto_config,
332 			max_dataqueues, &max_data_queues);
333 	if (max_data_queues < 1)
334 		max_data_queues = 1;
335 
336 	virtio_cread(vdev, struct virtio_crypto_config,
337 		max_cipher_key_len, &max_cipher_key_len);
338 	virtio_cread(vdev, struct virtio_crypto_config,
339 		max_auth_key_len, &max_auth_key_len);
340 	virtio_cread(vdev, struct virtio_crypto_config,
341 		max_size, &max_size);
342 
343 	/* Add virtio crypto device to global table */
344 	err = virtcrypto_devmgr_add_dev(vcrypto);
345 	if (err) {
346 		dev_err(&vdev->dev, "Failed to add new virtio crypto device.\n");
347 		goto free;
348 	}
349 	vcrypto->owner = THIS_MODULE;
350 	vcrypto = vdev->priv = vcrypto;
351 	vcrypto->vdev = vdev;
352 
353 	spin_lock_init(&vcrypto->ctrl_lock);
354 
355 	/* Use single data queue as default */
356 	vcrypto->curr_queue = 1;
357 	vcrypto->max_data_queues = max_data_queues;
358 	vcrypto->max_cipher_key_len = max_cipher_key_len;
359 	vcrypto->max_auth_key_len = max_auth_key_len;
360 	vcrypto->max_size = max_size;
361 
362 	dev_info(&vdev->dev,
363 		"max_queues: %u, max_cipher_key_len: %u, max_auth_key_len: %u, max_size 0x%llx\n",
364 		vcrypto->max_data_queues,
365 		vcrypto->max_cipher_key_len,
366 		vcrypto->max_auth_key_len,
367 		vcrypto->max_size);
368 
369 	err = virtcrypto_init_vqs(vcrypto);
370 	if (err) {
371 		dev_err(&vdev->dev, "Failed to initialize vqs.\n");
372 		goto free_dev;
373 	}
374 
375 	err = virtcrypto_start_crypto_engines(vcrypto);
376 	if (err)
377 		goto free_vqs;
378 
379 	virtio_device_ready(vdev);
380 
381 	err = virtcrypto_update_status(vcrypto);
382 	if (err)
383 		goto free_engines;
384 
385 	return 0;
386 
387 free_engines:
388 	virtcrypto_clear_crypto_engines(vcrypto);
389 free_vqs:
390 	vcrypto->vdev->config->reset(vdev);
391 	virtcrypto_del_vqs(vcrypto);
392 free_dev:
393 	virtcrypto_devmgr_rm_dev(vcrypto);
394 free:
395 	kfree(vcrypto);
396 	return err;
397 }
398 
399 static void virtcrypto_free_unused_reqs(struct virtio_crypto *vcrypto)
400 {
401 	struct virtio_crypto_request *vc_req;
402 	int i;
403 	struct virtqueue *vq;
404 
405 	for (i = 0; i < vcrypto->max_data_queues; i++) {
406 		vq = vcrypto->data_vq[i].vq;
407 		while ((vc_req = virtqueue_detach_unused_buf(vq)) != NULL) {
408 			kfree(vc_req->req_data);
409 			kfree(vc_req->sgs);
410 		}
411 	}
412 }
413 
414 static void virtcrypto_remove(struct virtio_device *vdev)
415 {
416 	struct virtio_crypto *vcrypto = vdev->priv;
417 
418 	dev_info(&vdev->dev, "Start virtcrypto_remove.\n");
419 
420 	if (virtcrypto_dev_started(vcrypto))
421 		virtcrypto_dev_stop(vcrypto);
422 	vdev->config->reset(vdev);
423 	virtcrypto_free_unused_reqs(vcrypto);
424 	virtcrypto_clear_crypto_engines(vcrypto);
425 	virtcrypto_del_vqs(vcrypto);
426 	virtcrypto_devmgr_rm_dev(vcrypto);
427 	kfree(vcrypto);
428 }
429 
430 static void virtcrypto_config_changed(struct virtio_device *vdev)
431 {
432 	struct virtio_crypto *vcrypto = vdev->priv;
433 
434 	virtcrypto_update_status(vcrypto);
435 }
436 
437 #ifdef CONFIG_PM_SLEEP
438 static int virtcrypto_freeze(struct virtio_device *vdev)
439 {
440 	struct virtio_crypto *vcrypto = vdev->priv;
441 
442 	vdev->config->reset(vdev);
443 	virtcrypto_free_unused_reqs(vcrypto);
444 	if (virtcrypto_dev_started(vcrypto))
445 		virtcrypto_dev_stop(vcrypto);
446 
447 	virtcrypto_clear_crypto_engines(vcrypto);
448 	virtcrypto_del_vqs(vcrypto);
449 	return 0;
450 }
451 
452 static int virtcrypto_restore(struct virtio_device *vdev)
453 {
454 	struct virtio_crypto *vcrypto = vdev->priv;
455 	int err;
456 
457 	err = virtcrypto_init_vqs(vcrypto);
458 	if (err)
459 		return err;
460 
461 	err = virtcrypto_start_crypto_engines(vcrypto);
462 	if (err)
463 		goto free_vqs;
464 
465 	virtio_device_ready(vdev);
466 
467 	err = virtcrypto_dev_start(vcrypto);
468 	if (err) {
469 		dev_err(&vdev->dev, "Failed to start virtio crypto device.\n");
470 		goto free_engines;
471 	}
472 
473 	return 0;
474 
475 free_engines:
476 	virtcrypto_clear_crypto_engines(vcrypto);
477 free_vqs:
478 	vcrypto->vdev->config->reset(vdev);
479 	virtcrypto_del_vqs(vcrypto);
480 	return err;
481 }
482 #endif
483 
484 static unsigned int features[] = {
485 	/* none */
486 };
487 
488 static struct virtio_device_id id_table[] = {
489 	{ VIRTIO_ID_CRYPTO, VIRTIO_DEV_ANY_ID },
490 	{ 0 },
491 };
492 
493 static struct virtio_driver virtio_crypto_driver = {
494 	.driver.name         = KBUILD_MODNAME,
495 	.driver.owner        = THIS_MODULE,
496 	.feature_table       = features,
497 	.feature_table_size  = ARRAY_SIZE(features),
498 	.id_table            = id_table,
499 	.probe               = virtcrypto_probe,
500 	.remove              = virtcrypto_remove,
501 	.config_changed = virtcrypto_config_changed,
502 #ifdef CONFIG_PM_SLEEP
503 	.freeze = virtcrypto_freeze,
504 	.restore = virtcrypto_restore,
505 #endif
506 };
507 
508 module_virtio_driver(virtio_crypto_driver);
509 
510 MODULE_DEVICE_TABLE(virtio, id_table);
511 MODULE_DESCRIPTION("virtio crypto device driver");
512 MODULE_LICENSE("GPL");
513 MODULE_AUTHOR("Gonglei <arei.gonglei@huawei.com>");
514