summaryrefslogtreecommitdiffstats
path: root/crypto/crypto_engine.c
blob: 412149e8e3dc932789e61f72df2561cfbc9f146a (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
// SPDX-License-Identifier: GPL-2.0-or-later
/*
 * Handle async block request by crypto hardware engine.
 *
 * Copyright (C) 2016 Linaro, Inc.
 *
 * Author: Baolin Wang <baolin.wang@linaro.org>
 */

#include <linux/err.h>
#include <linux/delay.h>
#include <crypto/engine.h>
#include <uapi/linux/sched/types.h>
#include "internal.h"

#define CRYPTO_ENGINE_MAX_QLEN 10

/**
 * crypto_finalize_request - finalize one request if the request is done
 * @engine: the hardware engine
 * @req: the request need to be finalized
 * @err: error number
 */
static void crypto_finalize_request(struct crypto_engine *engine,
				    struct crypto_async_request *req, int err)
{
	unsigned long flags;
	bool finalize_req = false;
	int ret;
	struct crypto_engine_ctx *enginectx;

	/*
	 * If hardware cannot enqueue more requests
	 * and retry mechanism is not supported
	 * make sure we are completing the current request
	 */
	if (!engine->retry_support) {
		spin_lock_irqsave(&engine->queue_lock, flags);
		if (engine->cur_req == req) {
			finalize_req = true;
			engine->cur_req = NULL;
		}
		spin_unlock_irqrestore(&engine->queue_lock, flags);
	}

	if (finalize_req || engine->retry_support) {
		enginectx = crypto_tfm_ctx(req->tfm);
		if (enginectx->op.prepare_request &&
		    enginectx->op.unprepare_request) {
			ret = enginectx->op.unprepare_request(engine, req);
			if (ret)
				dev_err(engine->dev, "failed to unprepare request\n");
		}
	}
	req->complete(req, err);

	kthread_queue_work(engine->kworker, &engine->pump_requests);
}

/**
 * crypto_pump_requests - dequeue one request from engine queue to process
 * @engine: the hardware engine
 * @in_kthread: true if we are in the context of the request pump thread
 *
 * This function checks if there is any request in the engine queue that
 * needs processing and if so call out to the driver to initialize hardware
 * and handle each request.
 */
static void crypto_pump_requests(struct crypto_engine *engine,
				 bool in_kthread)
{
	struct crypto_async_request *async_req, *backlog;
	unsigned long flags;
	bool was_busy = false;
	int ret;
	struct crypto_engine_ctx *enginectx;

	spin_lock_irqsave(&engine->queue_lock, flags);

	/* Make sure we are not already running a request */
	if (!engine->retry_support && engine->cur_req)
		goto out;

	/* If another context is idling then defer */
	if (engine->idling) {
		kthread_queue_work(engine->kworker, &engine->pump_requests);
		goto out;
	}

	/* Check if the engine queue is idle */
	if (!crypto_queue_len(&engine->queue) || !engine->running) {
		if (!engine->busy)
			goto out;

		/* Only do teardown in the thread */
		if (!in_kthread) {
			kthread_queue_work(engine->kworker,
					   &engine->pump_requests);
			goto out;
		}

		engine->busy = false;
		engine->idling = true;
		spin_unlock_irqrestore(&engine->queue_lock, flags);

		if (engine->unprepare_crypt_hardware &&
		    engine->unprepare_crypt_hardware(engine))
			dev_err(engine->dev, "failed to unprepare crypt hardware\n");

		spin_lock_irqsave(&engine->queue_lock, flags);
		engine->idling = false;
		goto out;
	}

start_request:
	/* Get the fist request from the engine queue to handle */
	backlog = crypto_get_backlog(&engine->queue);
	async_req = crypto_dequeue_request(&engine->queue);
	if (!async_req)
		goto out;

	/*
	 * If hardware doesn't support the retry mechanism,
	 * keep track of the request we are processing now.
	 * We'll need it on completion (crypto_finalize_request).
	 */
	if (!engine->retry_support)
		engine->cur_req = async_req;

	if (backlog)
		backlog->complete(backlog, -EINPROGRESS);

	if (engine->busy)
		was_busy = true;
	else
		engine->busy = true;

	spin_unlock_irqrestore(&engine->queue_lock, flags);

	/* Until here we get the request need to be encrypted successfully */
	if (!was_busy && engine->prepare_crypt_hardware) {
		ret = engine->prepare_crypt_hardware(engine);
		if (ret) {
			dev_err(engine->dev, "failed to prepare crypt hardware\n");
			goto req_err_2;
		}
	}

	enginectx = crypto_tfm_ctx(async_req->tfm);

	if (enginectx->op.prepare_request) {
		ret = enginectx->op.prepare_request(engine, async_req);
		if (ret) {
			dev_err(engine->dev, "failed to prepare request: %d\n",
				ret);
			goto req_err_2;
		}
	}
	if (!enginectx->op.do_one_request) {
		dev_err(engine->dev, "failed to do request\n");
		ret = -EINVAL;
		goto req_err_1;
	}

	ret = enginectx->op.do_one_request(engine, async_req);

	/* Request unsuccessfully executed by hardware */
	if (ret < 0) {
		/*
		 * If hardware queue is full (-ENOSPC), requeue request
		 * regardless of backlog flag.
		 * If hardware throws any other error code,
		 * requeue only backlog requests.
		 * Otherwise, unprepare and complete the request.
		 */
		if (!engine->retry_support ||
		    ((ret != -ENOSPC) &&
		    !(async_req->flags & CRYPTO_TFM_REQ_MAY_BACKLOG))) {
			dev_err(engine->dev,
				"Failed to do one request from queue: %d\n",
				ret);
			goto req_err_1;
		}
		/*
		 * If retry mechanism is supported,
		 * unprepare current request and
		 * enqueue it back into crypto-engine queue.
		 */
		if (enginectx->op.unprepare_request) {
			ret = enginectx->op.unprepare_request(engine,
							      async_req);
			if (ret)
				dev_err(engine->dev,
					"failed to unprepare request\n");
		}
		spin_lock_irqsave(&engine->queue_lock, flags);
		/*
		 * If hardware was unable to execute request, enqueue it
		 * back in front of crypto-engine queue, to keep the order
		 * of requests.
		 */
		crypto_enqueue_request_head(&engine->queue, async_req);

		kthread_queue_work(engine->kworker, &engine->pump_requests);
		goto out;
	}

	goto retry;

req_err_1:
	if (enginectx->op.unprepare_request) {
		ret = enginectx->op.unprepare_request(engine, async_req);
		if (ret)
			dev_err(engine->dev, "failed to unprepare request\n");
	}

req_err_2:
	async_req->complete(async_req, ret);

retry:
	/* If retry mechanism is supported, send new requests to engine */
	if (engine->retry_support) {
		spin_lock_irqsave(&engine->queue_lock, flags);
		goto start_request;
	}
	return;

out:
	spin_unlock_irqrestore(&engine->queue_lock, flags);

	/*
	 * Batch requests is possible only if
	 * hardware can enqueue multiple requests
	 */
	if (engine->do_batch_requests) {
		ret = engine->do_batch_requests(engine);
		if (ret)
			dev_err(engine->dev, "failed to do batch requests: %d\n",
				ret);
	}

	return;
}

static void crypto_pump_work(struct kthread_work *work)
{
	struct crypto_engine *engine =
		container_of(work, struct crypto_engine, pump_requests);

	crypto_pump_requests(engine, true);
}

/**
 * crypto_transfer_request - transfer the new request into the engine queue
 * @engine: the hardware engine
 * @req: the request need to be listed into the engine queue
 */
static int crypto_transfer_request(struct crypto_engine *engine,
				   struct crypto_async_request *req,
				   bool need_pump)
{
	unsigned long flags;
	int ret;

	spin_lock_irqsave(&engine->queue_lock, flags);

	if (!engine->running) {
		spin_unlock_irqrestore(&engine->queue_lock, flags);
		return -ESHUTDOWN;
	}

	ret = crypto_enqueue_request(&engine->queue, req);

	if (!engine->busy && need_pump)
		kthread_queue_work(engine->kworker, &engine->pump_requests);

	spin_unlock_irqrestore(&engine->queue_lock, flags);
	return ret;
}

/**
 * crypto_transfer_request_to_engine - transfer one request to list
 * into the engine queue
 * @engine: the hardware engine
 * @req: the request need to be listed into the engine queue
 */
static int crypto_transfer_request_to_engine(struct crypto_engine *engine,
					     struct crypto_async_request *req)
{
	return crypto_transfer_request(engine, req, true);
}

/**
 * crypto_transfer_aead_request_to_engine - transfer one aead_request
 * to list into the engine queue
 * @engine: the hardware engine
 * @req: the request need to be listed into the engine queue
 */
int crypto_transfer_aead_request_to_engine(struct crypto_engine *engine,
					   struct aead_request *req)
{
	return crypto_transfer_request_to_engine(engine, &req->base);
}
EXPORT_SYMBOL_GPL(crypto_transfer_aead_request_to_engine);

/**
 * crypto_transfer_akcipher_request_to_engine - transfer one akcipher_request
 * to list into the engine queue
 * @engine: the hardware engine
 * @req: the request need to be listed into the engine queue
 */
int crypto_transfer_akcipher_request_to_engine(struct crypto_engine *engine,
					       struct akcipher_request *req)
{
	return crypto_transfer_request_to_engine(engine, &req->base);
}
EXPORT_SYMBOL_GPL(crypto_transfer_akcipher_request_to_engine);

/**
 * crypto_transfer_hash_request_to_engine - transfer one ahash_request
 * to list into the engine queue
 * @engine: the hardware engine
 * @req: the request need to be listed into the engine queue
 */
int crypto_transfer_hash_request_to_engine(struct crypto_engine *engine,
					   struct ahash_request *req)
{
	return crypto_transfer_request_to_engine(engine, &req->base);
}
EXPORT_SYMBOL_GPL(crypto_transfer_hash_request_to_engine);

/**
 * crypto_transfer_skcipher_request_to_engine - transfer one skcipher_request
 * to list into the engine queue
 * @engine: the hardware engine
 * @req: the request need to be listed into the engine queue
 */
int crypto_transfer_skcipher_request_to_engine(struct crypto_engine *engine,
					       struct skcipher_request *req)
{
	return crypto_transfer_request_to_engine(engine, &req->base);
}
EXPORT_SYMBOL_GPL(crypto_transfer_skcipher_request_to_engine);

/**
 * crypto_finalize_aead_request - finalize one aead_request if
 * the request is done
 * @engine: the hardware engine
 * @req: the request need to be finalized
 * @err: error number
 */
void crypto_finalize_aead_request(struct crypto_engine *engine,
				  struct aead_request *req, int err)
{
	return crypto_finalize_request(engine, &req->base, err);
}
EXPORT_SYMBOL_GPL(crypto_finalize_aead_request);

/**
 * crypto_finalize_akcipher_request - finalize one akcipher_request if
 * the request is done
 * @engine: the hardware engine
 * @req: the request need to be finalized
 * @err: error number
 */
void crypto_finalize_akcipher_request(struct crypto_engine *engine,
				      struct akcipher_request *req, int err)
{
	return crypto_finalize_request(engine, &req->base, err);
}
EXPORT_SYMBOL_GPL(crypto_finalize_akcipher_request);

/**
 * crypto_finalize_hash_request - finalize one ahash_request if
 * the request is done
 * @engine: the hardware engine
 * @req: the request need to be finalized
 * @err: error number
 */
void crypto_finalize_hash_request(struct crypto_engine *engine,
				  struct ahash_request *req, int err)
{
	return crypto_finalize_request(engine, &req->base, err);
}
EXPORT_SYMBOL_GPL(crypto_finalize_hash_request);

/**
 * crypto_finalize_skcipher_request - finalize one skcipher_request if
 * the request is done
 * @engine: the hardware engine
 * @req: the request need to be finalized
 * @err: error number
 */
void crypto_finalize_skcipher_request(struct crypto_engine *engine,
				      struct skcipher_request *req, int err)
{
	return crypto_finalize_request(engine, &req->base, err);
}
EXPORT_SYMBOL_GPL(crypto_finalize_skcipher_request);

/**
 * crypto_engine_start - start the hardware engine
 * @engine: the hardware engine need to be started
 *
 * Return 0 on success, else on fail.
 */
int crypto_engine_start(struct crypto_engine *engine)
{
	unsigned long flags;

	spin_lock_irqsave(&engine->queue_lock, flags);

	if (engine->running || engine->busy) {
		spin_unlock_irqrestore(&engine->queue_lock, flags);
		return -EBUSY;
	}

	engine->running = true;
	spin_unlock_irqrestore(&engine->queue_lock, flags);

	kthread_queue_work(engine->kworker, &engine->pump_requests);

	return 0;
}
EXPORT_SYMBOL_GPL(crypto_engine_start);

/**
 * crypto_engine_stop - stop the hardware engine
 * @engine: the hardware engine need to be stopped
 *
 * Return 0 on success, else on fail.
 */
int crypto_engine_stop(struct crypto_engine *engine)
{
	unsigned long flags;
	unsigned int limit = 500;
	int ret = 0;

	spin_lock_irqsave(&engine->queue_lock, flags);

	/*
	 * If the engine queue is not empty or the engine is on busy state,
	 * we need to wait for a while to pump the requests of engine queue.
	 */
	while ((crypto_queue_len(&engine->queue) || engine->busy) && limit--) {
		spin_unlock_irqrestore(&engine->queue_lock, flags);
		msleep(20);
		spin_lock_irqsave(&engine->queue_lock, flags);
	}

	if (crypto_queue_len(&engine->queue) || engine->busy)
		ret = -EBUSY;
	else
		engine->running = false;

	spin_unlock_irqrestore(&engine->queue_lock, flags);

	if (ret)
		dev_warn(engine->dev, "could not stop engine\n");

	return ret;
}
EXPORT_SYMBOL_GPL(crypto_engine_stop);

/**
 * crypto_engine_alloc_init_and_set - allocate crypto hardware engine structure
 * and initialize it by setting the maximum number of entries in the software
 * crypto-engine queue.
 * @dev: the device attached with one hardware engine
 * @retry_support: whether hardware has support for retry mechanism
 * @cbk_do_batch: pointer to a callback function to be invoked when executing a
 *                a batch of requests.
 *                This has the form:
 *                callback(struct crypto_engine *engine)
 *                where:
 *                @engine: the crypto engine structure.
 * @rt: whether this queue is set to run as a realtime task
 * @qlen: maximum size of the crypto-engine queue
 *
 * This must be called from context that can sleep.
 * Return: the crypto engine structure on success, else NULL.
 */
struct crypto_engine *crypto_engine_alloc_init_and_set(struct device *dev,
						       bool retry_support,
						       int (*cbk_do_batch)(struct crypto_engine *engine),
						       bool rt, int qlen)
{
	struct sched_param param = { .sched_priority = MAX_RT_PRIO / 2 };
	struct crypto_engine *engine;

	if (!dev)
		return NULL;

	engine = devm_kzalloc(dev, sizeof(*engine), GFP_KERNEL);
	if (!engine)
		return NULL;

	engine->dev = dev;
	engine->rt = rt;
	engine->running = false;
	engine->busy = false;
	engine->idling = false;
	engine->retry_support = retry_support;
	engine->priv_data = dev;
	/*
	 * Batch requests is possible only if
	 * hardware has support for retry mechanism.
	 */
	engine->do_batch_requests = retry_support ? cbk_do_batch : NULL;

	snprintf(engine->name, sizeof(engine->name),
		 "%s-engine", dev_name(dev));

	crypto_init_queue(&engine->queue, qlen);
	spin_lock_init(&engine->queue_lock);

	engine->kworker = kthread_create_worker(0, "%s", engine->name);
	if (IS_ERR(engine->kworker)) {
		dev_err(dev, "failed to create crypto request pump task\n");
		return NULL;
	}
	kthread_init_work(&engine->pump_requests, crypto_pump_work);

	if (engine->rt) {
		dev_info(dev, "will run requests pump with realtime priority\n");
		sched_setscheduler(engine->kworker->task, SCHED_FIFO, &param);
	}

	return engine;
}
EXPORT_SYMBOL_GPL(crypto_engine_alloc_init_and_set);

/**
 * crypto_engine_alloc_init - allocate crypto hardware engine structure and
 * initialize it.
 * @dev: the device attached with one hardware engine
 * @rt: whether this queue is set to run as a realtime task
 *
 * This must be called from context that can sleep.
 * Return: the crypto engine structure on success, else NULL.
 */
struct crypto_engine *crypto_engine_alloc_init(struct device *dev, bool rt)
{
	return crypto_engine_alloc_init_and_set(dev, false, NULL, rt,
						CRYPTO_ENGINE_MAX_QLEN);
}
EXPORT_SYMBOL_GPL(crypto_engine_alloc_init);

/**
 * crypto_engine_exit - free the resources of hardware engine when exit
 * @engine: the hardware engine need to be freed
 *
 * Return 0 for success.
 */
int crypto_engine_exit(struct crypto_engine *engine)
{
	int ret;

	ret = crypto_engine_stop(engine);
	if (ret)
		return ret;

	kthread_destroy_worker(engine->kworker);

	return 0;
}
EXPORT_SYMBOL_GPL(crypto_engine_exit);

MODULE_LICENSE("GPL");
MODULE_DESCRIPTION("Crypto hardware engine framework");