1/*
2 * Handle async block request by crypto hardware engine.
3 *
4 * Copyright (C) 2016 Linaro, Inc.
5 *
6 * Author: Baolin Wang <baolin.wang@linaro.org>
7 *
8 * This program is free software; you can redistribute it and/or modify it
9 * under the terms of the GNU General Public License as published by the Free
10 * Software Foundation; either version 2 of the License, or (at your option)
11 * any later version.
12 *
13 */
14
15#include <linux/err.h>
16#include <linux/delay.h>
17#include <crypto/engine.h>
18#include <uapi/linux/sched/types.h>
19#include "internal.h"
20
21#define CRYPTO_ENGINE_MAX_QLEN 10
22
23/**
24 * crypto_finalize_request - finalize one request if the request is done
25 * @engine: the hardware engine
26 * @req: the request need to be finalized
27 * @err: error number
28 */
29static void crypto_finalize_request(struct crypto_engine *engine,
30 struct crypto_async_request *req, int err)
31{
32 unsigned long flags;
33 bool finalize_cur_req = false;
34 int ret;
35 struct crypto_engine_ctx *enginectx;
36
37 spin_lock_irqsave(&engine->queue_lock, flags);
38 if (engine->cur_req == req)
39 finalize_cur_req = true;
40 spin_unlock_irqrestore(&engine->queue_lock, flags);
41
42 if (finalize_cur_req) {
43 enginectx = crypto_tfm_ctx(req->tfm);
44 if (engine->cur_req_prepared &&
45 enginectx->op.unprepare_request) {
46 ret = enginectx->op.unprepare_request(engine, req);
47 if (ret)
48 dev_err(engine->dev, "failed to unprepare request\n");
49 }
50 spin_lock_irqsave(&engine->queue_lock, flags);
51 engine->cur_req = NULL;
52 engine->cur_req_prepared = false;
53 spin_unlock_irqrestore(&engine->queue_lock, flags);
54 }
55
56 req->complete(req, err);
57
58 kthread_queue_work(engine->kworker, &engine->pump_requests);
59}
60
61/**
62 * crypto_pump_requests - dequeue one request from engine queue to process
63 * @engine: the hardware engine
64 * @in_kthread: true if we are in the context of the request pump thread
65 *
66 * This function checks if there is any request in the engine queue that
67 * needs processing and if so call out to the driver to initialize hardware
68 * and handle each request.
69 */
70static void crypto_pump_requests(struct crypto_engine *engine,
71 bool in_kthread)
72{
73 struct crypto_async_request *async_req, *backlog;
74 unsigned long flags;
75 bool was_busy = false;
76 int ret;
77 struct crypto_engine_ctx *enginectx;
78
79 spin_lock_irqsave(&engine->queue_lock, flags);
80
81 /* Make sure we are not already running a request */
82 if (engine->cur_req)
83 goto out;
84
85 /* If another context is idling then defer */
86 if (engine->idling) {
87 kthread_queue_work(engine->kworker, &engine->pump_requests);
88 goto out;
89 }
90
91 /* Check if the engine queue is idle */
92 if (!crypto_queue_len(&engine->queue) || !engine->running) {
93 if (!engine->busy)
94 goto out;
95
96 /* Only do teardown in the thread */
97 if (!in_kthread) {
98 kthread_queue_work(engine->kworker,
99 &engine->pump_requests);
100 goto out;
101 }
102
103 engine->busy = false;
104 engine->idling = true;
105 spin_unlock_irqrestore(&engine->queue_lock, flags);
106
107 if (engine->unprepare_crypt_hardware &&
108 engine->unprepare_crypt_hardware(engine))
109 dev_err(engine->dev, "failed to unprepare crypt hardware\n");
110
111 spin_lock_irqsave(&engine->queue_lock, flags);
112 engine->idling = false;
113 goto out;
114 }
115
116 /* Get the fist request from the engine queue to handle */
117 backlog = crypto_get_backlog(&engine->queue);
118 async_req = crypto_dequeue_request(&engine->queue);
119 if (!async_req)
120 goto out;
121
122 engine->cur_req = async_req;
123 if (backlog)
124 backlog->complete(backlog, -EINPROGRESS);
125
126 if (engine->busy)
127 was_busy = true;
128 else
129 engine->busy = true;
130
131 spin_unlock_irqrestore(&engine->queue_lock, flags);
132
133 /* Until here we get the request need to be encrypted successfully */
134 if (!was_busy && engine->prepare_crypt_hardware) {
135 ret = engine->prepare_crypt_hardware(engine);
136 if (ret) {
137 dev_err(engine->dev, "failed to prepare crypt hardware\n");
138 goto req_err;
139 }
140 }
141
142 enginectx = crypto_tfm_ctx(async_req->tfm);
143
144 if (enginectx->op.prepare_request) {
145 ret = enginectx->op.prepare_request(engine, async_req);
146 if (ret) {
147 dev_err(engine->dev, "failed to prepare request: %d\n",
148 ret);
149 goto req_err;
150 }
151 engine->cur_req_prepared = true;
152 }
153 if (!enginectx->op.do_one_request) {
154 dev_err(engine->dev, "failed to do request\n");
155 ret = -EINVAL;
156 goto req_err;
157 }
158 ret = enginectx->op.do_one_request(engine, async_req);
159 if (ret) {
160 dev_err(engine->dev, "Failed to do one request from queue: %d\n", ret);
161 goto req_err;
162 }
163 return;
164
165req_err:
166 crypto_finalize_request(engine, async_req, ret);
167 return;
168
169out:
170 spin_unlock_irqrestore(&engine->queue_lock, flags);
171}
172
173static void crypto_pump_work(struct kthread_work *work)
174{
175 struct crypto_engine *engine =
176 container_of(work, struct crypto_engine, pump_requests);
177
178 crypto_pump_requests(engine, true);
179}
180
181/**
182 * crypto_transfer_request - transfer the new request into the engine queue
183 * @engine: the hardware engine
184 * @req: the request need to be listed into the engine queue
185 */
186static int crypto_transfer_request(struct crypto_engine *engine,
187 struct crypto_async_request *req,
188 bool need_pump)
189{
190 unsigned long flags;
191 int ret;
192
193 spin_lock_irqsave(&engine->queue_lock, flags);
194
195 if (!engine->running) {
196 spin_unlock_irqrestore(&engine->queue_lock, flags);
197 return -ESHUTDOWN;
198 }
199
200 ret = crypto_enqueue_request(&engine->queue, req);
201
202 if (!engine->busy && need_pump)
203 kthread_queue_work(engine->kworker, &engine->pump_requests);
204
205 spin_unlock_irqrestore(&engine->queue_lock, flags);
206 return ret;
207}
208
209/**
210 * crypto_transfer_request_to_engine - transfer one request to list
211 * into the engine queue
212 * @engine: the hardware engine
213 * @req: the request need to be listed into the engine queue
214 */
215static int crypto_transfer_request_to_engine(struct crypto_engine *engine,
216 struct crypto_async_request *req)
217{
218 return crypto_transfer_request(engine, req, true);
219}
220
221/**
222 * crypto_transfer_ablkcipher_request_to_engine - transfer one ablkcipher_request
223 * to list into the engine queue
224 * @engine: the hardware engine
225 * @req: the request need to be listed into the engine queue
226 * TODO: Remove this function when skcipher conversion is finished
227 */
228int crypto_transfer_ablkcipher_request_to_engine(struct crypto_engine *engine,
229 struct ablkcipher_request *req)
230{
231 return crypto_transfer_request_to_engine(engine, &req->base);
232}
233EXPORT_SYMBOL_GPL(crypto_transfer_ablkcipher_request_to_engine);
234
235/**
236 * crypto_transfer_aead_request_to_engine - transfer one aead_request
237 * to list into the engine queue
238 * @engine: the hardware engine
239 * @req: the request need to be listed into the engine queue
240 */
241int crypto_transfer_aead_request_to_engine(struct crypto_engine *engine,
242 struct aead_request *req)
243{
244 return crypto_transfer_request_to_engine(engine, &req->base);
245}
246EXPORT_SYMBOL_GPL(crypto_transfer_aead_request_to_engine);
247
248/**
249 * crypto_transfer_akcipher_request_to_engine - transfer one akcipher_request
250 * to list into the engine queue
251 * @engine: the hardware engine
252 * @req: the request need to be listed into the engine queue
253 */
254int crypto_transfer_akcipher_request_to_engine(struct crypto_engine *engine,
255 struct akcipher_request *req)
256{
257 return crypto_transfer_request_to_engine(engine, &req->base);
258}
259EXPORT_SYMBOL_GPL(crypto_transfer_akcipher_request_to_engine);
260
261/**
262 * crypto_transfer_hash_request_to_engine - transfer one ahash_request
263 * to list into the engine queue
264 * @engine: the hardware engine
265 * @req: the request need to be listed into the engine queue
266 */
267int crypto_transfer_hash_request_to_engine(struct crypto_engine *engine,
268 struct ahash_request *req)
269{
270 return crypto_transfer_request_to_engine(engine, &req->base);
271}
272EXPORT_SYMBOL_GPL(crypto_transfer_hash_request_to_engine);
273
274/**
275 * crypto_transfer_skcipher_request_to_engine - transfer one skcipher_request
276 * to list into the engine queue
277 * @engine: the hardware engine
278 * @req: the request need to be listed into the engine queue
279 */
280int crypto_transfer_skcipher_request_to_engine(struct crypto_engine *engine,
281 struct skcipher_request *req)
282{
283 return crypto_transfer_request_to_engine(engine, &req->base);
284}
285EXPORT_SYMBOL_GPL(crypto_transfer_skcipher_request_to_engine);
286
287/**
288 * crypto_finalize_ablkcipher_request - finalize one ablkcipher_request if
289 * the request is done
290 * @engine: the hardware engine
291 * @req: the request need to be finalized
292 * @err: error number
293 * TODO: Remove this function when skcipher conversion is finished
294 */
295void crypto_finalize_ablkcipher_request(struct crypto_engine *engine,
296 struct ablkcipher_request *req, int err)
297{
298 return crypto_finalize_request(engine, &req->base, err);
299}
300EXPORT_SYMBOL_GPL(crypto_finalize_ablkcipher_request);
301
302/**
303 * crypto_finalize_aead_request - finalize one aead_request if
304 * the request is done
305 * @engine: the hardware engine
306 * @req: the request need to be finalized
307 * @err: error number
308 */
309void crypto_finalize_aead_request(struct crypto_engine *engine,
310 struct aead_request *req, int err)
311{
312 return crypto_finalize_request(engine, &req->base, err);
313}
314EXPORT_SYMBOL_GPL(crypto_finalize_aead_request);
315
316/**
317 * crypto_finalize_akcipher_request - finalize one akcipher_request if
318 * the request is done
319 * @engine: the hardware engine
320 * @req: the request need to be finalized
321 * @err: error number
322 */
323void crypto_finalize_akcipher_request(struct crypto_engine *engine,
324 struct akcipher_request *req, int err)
325{
326 return crypto_finalize_request(engine, &req->base, err);
327}
328EXPORT_SYMBOL_GPL(crypto_finalize_akcipher_request);
329
330/**
331 * crypto_finalize_hash_request - finalize one ahash_request if
332 * the request is done
333 * @engine: the hardware engine
334 * @req: the request need to be finalized
335 * @err: error number
336 */
337void crypto_finalize_hash_request(struct crypto_engine *engine,
338 struct ahash_request *req, int err)
339{
340 return crypto_finalize_request(engine, &req->base, err);
341}
342EXPORT_SYMBOL_GPL(crypto_finalize_hash_request);
343
344/**
345 * crypto_finalize_skcipher_request - finalize one skcipher_request if
346 * the request is done
347 * @engine: the hardware engine
348 * @req: the request need to be finalized
349 * @err: error number
350 */
351void crypto_finalize_skcipher_request(struct crypto_engine *engine,
352 struct skcipher_request *req, int err)
353{
354 return crypto_finalize_request(engine, &req->base, err);
355}
356EXPORT_SYMBOL_GPL(crypto_finalize_skcipher_request);
357
358/**
359 * crypto_engine_start - start the hardware engine
360 * @engine: the hardware engine need to be started
361 *
362 * Return 0 on success, else on fail.
363 */
364int crypto_engine_start(struct crypto_engine *engine)
365{
366 unsigned long flags;
367
368 spin_lock_irqsave(&engine->queue_lock, flags);
369
370 if (engine->running || engine->busy) {
371 spin_unlock_irqrestore(&engine->queue_lock, flags);
372 return -EBUSY;
373 }
374
375 engine->running = true;
376 spin_unlock_irqrestore(&engine->queue_lock, flags);
377
378 kthread_queue_work(engine->kworker, &engine->pump_requests);
379
380 return 0;
381}
382EXPORT_SYMBOL_GPL(crypto_engine_start);
383
384/**
385 * crypto_engine_stop - stop the hardware engine
386 * @engine: the hardware engine need to be stopped
387 *
388 * Return 0 on success, else on fail.
389 */
390int crypto_engine_stop(struct crypto_engine *engine)
391{
392 unsigned long flags;
393 unsigned int limit = 500;
394 int ret = 0;
395
396 spin_lock_irqsave(&engine->queue_lock, flags);
397
398 /*
399 * If the engine queue is not empty or the engine is on busy state,
400 * we need to wait for a while to pump the requests of engine queue.
401 */
402 while ((crypto_queue_len(&engine->queue) || engine->busy) && limit--) {
403 spin_unlock_irqrestore(&engine->queue_lock, flags);
404 msleep(20);
405 spin_lock_irqsave(&engine->queue_lock, flags);
406 }
407
408 if (crypto_queue_len(&engine->queue) || engine->busy)
409 ret = -EBUSY;
410 else
411 engine->running = false;
412
413 spin_unlock_irqrestore(&engine->queue_lock, flags);
414
415 if (ret)
416 dev_warn(engine->dev, "could not stop engine\n");
417
418 return ret;
419}
420EXPORT_SYMBOL_GPL(crypto_engine_stop);
421
422/**
423 * crypto_engine_alloc_init - allocate crypto hardware engine structure and
424 * initialize it.
425 * @dev: the device attached with one hardware engine
426 * @rt: whether this queue is set to run as a realtime task
427 *
428 * This must be called from context that can sleep.
429 * Return: the crypto engine structure on success, else NULL.
430 */
431struct crypto_engine *crypto_engine_alloc_init(struct device *dev, bool rt)
432{
433 struct sched_param param = { .sched_priority = MAX_RT_PRIO - 1 };
434 struct crypto_engine *engine;
435
436 if (!dev)
437 return NULL;
438
439 engine = devm_kzalloc(dev, sizeof(*engine), GFP_KERNEL);
440 if (!engine)
441 return NULL;
442
443 engine->dev = dev;
444 engine->rt = rt;
445 engine->running = false;
446 engine->busy = false;
447 engine->idling = false;
448 engine->cur_req_prepared = false;
449 engine->priv_data = dev;
450 snprintf(engine->name, sizeof(engine->name),
451 "%s-engine", dev_name(dev));
452
453 crypto_init_queue(&engine->queue, CRYPTO_ENGINE_MAX_QLEN);
454 spin_lock_init(&engine->queue_lock);
455
456 engine->kworker = kthread_create_worker(0, "%s", engine->name);
457 if (IS_ERR(engine->kworker)) {
458 dev_err(dev, "failed to create crypto request pump task\n");
459 return NULL;
460 }
461 kthread_init_work(&engine->pump_requests, crypto_pump_work);
462
463 if (engine->rt) {
464 dev_info(dev, "will run requests pump with realtime priority\n");
465 sched_setscheduler(engine->kworker->task, SCHED_FIFO, &param);
466 }
467
468 return engine;
469}
470EXPORT_SYMBOL_GPL(crypto_engine_alloc_init);
471
472/**
473 * crypto_engine_exit - free the resources of hardware engine when exit
474 * @engine: the hardware engine need to be freed
475 *
476 * Return 0 for success.
477 */
478int crypto_engine_exit(struct crypto_engine *engine)
479{
480 int ret;
481
482 ret = crypto_engine_stop(engine);
483 if (ret)
484 return ret;
485
486 kthread_destroy_worker(engine->kworker);
487
488 return 0;
489}
490EXPORT_SYMBOL_GPL(crypto_engine_exit);
491
492MODULE_LICENSE("GPL");
493MODULE_DESCRIPTION("Crypto hardware engine framework");
494