crypto/crypto_engine.c

   1 // SPDX-License-Identifier: GPL-2.0-or-later
   2 /*
   3  * Handle async block request by crypto hardware engine.
   4  *
   5  * Copyright (C) 2016 Linaro, Inc.
   6  *
   7  * Author: Baolin Wang <baolin.wang@linaro.org>
   8  */
   9
  10 #include <linux/err.h>
  11 #include <linux/delay.h>
  12 #include <crypto/engine.h>
  13 #include <uapi/linux/sched/types.h>
  14 #include "internal.h"
  15
  16 #define CRYPTO_ENGINE_MAX_QLEN 10
  17
  18 /**
  19  * crypto_finalize_request - finalize one request if the request is done
  20  * @engine: the hardware engine
  21  * @req: the request need to be finalized
  22  * @err: error number
  23  */
  24 static void crypto_finalize_request(struct crypto_engine *engine,
  25                                     struct crypto_async_request *req, int err)
  26 {
  27         unsigned long flags;
  28         bool finalize_req = false;
  29         int ret;
  30         struct crypto_engine_ctx *enginectx;
  31
  32         /*
  33          * If hardware cannot enqueue more requests
  34          * and retry mechanism is not supported
  35          * make sure we are completing the current request
  36          */
  37         if (!engine->retry_support) {
  38                 spin_lock_irqsave(&engine->queue_lock, flags);
  39                 if (engine->cur_req == req) {
  40                         finalize_req = true;
  41                         engine->cur_req = NULL;
  42                 }
  43                 spin_unlock_irqrestore(&engine->queue_lock, flags);
  44         }
  45
  46         if (finalize_req || engine->retry_support) {
  47                 enginectx = crypto_tfm_ctx(req->tfm);
  48                 if (enginectx->op.prepare_request &&
  49                     enginectx->op.unprepare_request) {
  50                         ret = enginectx->op.unprepare_request(engine, req);
  51                         if (ret)
  52                                 dev_err(engine->dev, "failed to unprepare request\n");
  53                 }
  54         }
  55         req->complete(req, err);
  56
  57         kthread_queue_work(engine->kworker, &engine->pump_requests);
  58 }
  59
  60 /**
  61  * crypto_pump_requests - dequeue one request from engine queue to process
  62  * @engine: the hardware engine
  63  * @in_kthread: true if we are in the context of the request pump thread
  64  *
  65  * This function checks if there is any request in the engine queue that
  66  * needs processing and if so call out to the driver to initialize hardware
  67  * and handle each request.
  68  */
  69 static void crypto_pump_requests(struct crypto_engine *engine,
  70                                  bool in_kthread)
  71 {
  72         struct crypto_async_request *async_req, *backlog;
  73         unsigned long flags;
  74         bool was_busy = false;
  75         int ret;
  76         struct crypto_engine_ctx *enginectx;
  77
  78         spin_lock_irqsave(&engine->queue_lock, flags);
  79
  80         /* Make sure we are not already running a request */
  81         if (!engine->retry_support && engine->cur_req)
  82                 goto out;
  83
  84         /* If another context is idling then defer */
  85         if (engine->idling) {
  86                 kthread_queue_work(engine->kworker, &engine->pump_requests);
  87                 goto out;
  88         }
  89
  90         /* Check if the engine queue is idle */
  91         if (!crypto_queue_len(&engine->queue) || !engine->running) {
  92                 if (!engine->busy)
  93                         goto out;
  94
  95                 /* Only do teardown in the thread */
  96                 if (!in_kthread) {
  97                         kthread_queue_work(engine->kworker,
  98                                            &engine->pump_requests);
  99                         goto out;
 100                 }
 101
 102                 engine->busy = false;
 103                 engine->idling = true;
 104                 spin_unlock_irqrestore(&engine->queue_lock, flags);
 105
 106                 if (engine->unprepare_crypt_hardware &&
 107                     engine->unprepare_crypt_hardware(engine))
 108                         dev_err(engine->dev, "failed to unprepare crypt hardware\n");
 109
 110                 spin_lock_irqsave(&engine->queue_lock, flags);
 111                 engine->idling = false;
 112                 goto out;
 113         }
 114
 115 start_request:
 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         /*
 123          * If hardware doesn't support the retry mechanism,
 124          * keep track of the request we are processing now.
 125          * We'll need it on completion (crypto_finalize_request).
 126          */
 127         if (!engine->retry_support)
 128                 engine->cur_req = async_req;
 129
 130         if (backlog)
 131                 backlog->complete(backlog, -EINPROGRESS);
 132
 133         if (engine->busy)
 134                 was_busy = true;
 135         else
 136                 engine->busy = true;
 137
 138         spin_unlock_irqrestore(&engine->queue_lock, flags);
 139
 140         /* Until here we get the request need to be encrypted successfully */
 141         if (!was_busy && engine->prepare_crypt_hardware) {
 142                 ret = engine->prepare_crypt_hardware(engine);
 143                 if (ret) {
 144                         dev_err(engine->dev, "failed to prepare crypt hardware\n");
 145                         goto req_err_2;
 146                 }
 147         }
 148
 149         enginectx = crypto_tfm_ctx(async_req->tfm);
 150
 151         if (enginectx->op.prepare_request) {
 152                 ret = enginectx->op.prepare_request(engine, async_req);
 153                 if (ret) {
 154                         dev_err(engine->dev, "failed to prepare request: %d\n",
 155                                 ret);
 156                         goto req_err_2;
 157                 }
 158         }
 159         if (!enginectx->op.do_one_request) {
 160                 dev_err(engine->dev, "failed to do request\n");
 161                 ret = -EINVAL;
 162                 goto req_err_1;
 163         }
 164
 165         ret = enginectx->op.do_one_request(engine, async_req);
 166
 167         /* Request unsuccessfully executed by hardware */
 168         if (ret < 0) {
 169                 /*
 170                  * If hardware queue is full (-ENOSPC), requeue request
 171                  * regardless of backlog flag.
 172                  * Otherwise, unprepare and complete the request.
 173                  */
 174                 if (!engine->retry_support ||
 175                     (ret != -ENOSPC)) {
 176                         dev_err(engine->dev,
 177                                 "Failed to do one request from queue: %d\n",
 178                                 ret);
 179                         goto req_err_1;
 180                 }
 181                 /*
 182                  * If retry mechanism is supported,
 183                  * unprepare current request and
 184                  * enqueue it back into crypto-engine queue.
 185                  */
 186                 if (enginectx->op.unprepare_request) {
 187                         ret = enginectx->op.unprepare_request(engine,
 188                                                               async_req);
 189                         if (ret)
 190                                 dev_err(engine->dev,
 191                                         "failed to unprepare request\n");
 192                 }
 193                 spin_lock_irqsave(&engine->queue_lock, flags);
 194                 /*
 195                  * If hardware was unable to execute request, enqueue it
 196                  * back in front of crypto-engine queue, to keep the order
 197                  * of requests.
 198                  */
 199                 crypto_enqueue_request_head(&engine->queue, async_req);
 200
 201                 kthread_queue_work(engine->kworker, &engine->pump_requests);
 202                 goto out;
 203         }
 204
 205         goto retry;
 206
 207 req_err_1:
 208         if (enginectx->op.unprepare_request) {
 209                 ret = enginectx->op.unprepare_request(engine, async_req);
 210                 if (ret)
 211                         dev_err(engine->dev, "failed to unprepare request\n");
 212         }
 213
 214 req_err_2:
 215         async_req->complete(async_req, ret);
 216
 217 retry:
 218         /* If retry mechanism is supported, send new requests to engine */
 219         if (engine->retry_support) {
 220                 spin_lock_irqsave(&engine->queue_lock, flags);
 221                 goto start_request;
 222         }
 223         return;
 224
 225 out:
 226         spin_unlock_irqrestore(&engine->queue_lock, flags);
 227
 228         /*
 229          * Batch requests is possible only if
 230          * hardware can enqueue multiple requests
 231          */
 232         if (engine->do_batch_requests) {
 233                 ret = engine->do_batch_requests(engine);
 234                 if (ret)
 235                         dev_err(engine->dev, "failed to do batch requests: %d\n",
 236                                 ret);
 237         }
 238
 239         return;
 240 }
 241
 242 static void crypto_pump_work(struct kthread_work *work)
 243 {
 244         struct crypto_engine *engine =
 245                 container_of(work, struct crypto_engine, pump_requests);
 246
 247         crypto_pump_requests(engine, true);
 248 }
 249
 250 /**
 251  * crypto_transfer_request - transfer the new request into the engine queue
 252  * @engine: the hardware engine
 253  * @req: the request need to be listed into the engine queue
 254  */
 255 static int crypto_transfer_request(struct crypto_engine *engine,
 256                                    struct crypto_async_request *req,
 257                                    bool need_pump)
 258 {
 259         unsigned long flags;
 260         int ret;
 261
 262         spin_lock_irqsave(&engine->queue_lock, flags);
 263
 264         if (!engine->running) {
 265                 spin_unlock_irqrestore(&engine->queue_lock, flags);
 266                 return -ESHUTDOWN;
 267         }
 268
 269         ret = crypto_enqueue_request(&engine->queue, req);
 270
 271         if (!engine->busy && need_pump)
 272                 kthread_queue_work(engine->kworker, &engine->pump_requests);
 273
 274         spin_unlock_irqrestore(&engine->queue_lock, flags);
 275         return ret;
 276 }
 277
 278 /**
 279  * crypto_transfer_request_to_engine - transfer one request to list
 280  * into the engine queue
 281  * @engine: the hardware engine
 282  * @req: the request need to be listed into the engine queue
 283  */
 284 static int crypto_transfer_request_to_engine(struct crypto_engine *engine,
 285                                              struct crypto_async_request *req)
 286 {
 287         return crypto_transfer_request(engine, req, true);
 288 }
 289
 290 /**
 291  * crypto_transfer_aead_request_to_engine - transfer one aead_request
 292  * to list into the engine queue
 293  * @engine: the hardware engine
 294  * @req: the request need to be listed into the engine queue
 295  */
 296 int crypto_transfer_aead_request_to_engine(struct crypto_engine *engine,
 297                                            struct aead_request *req)
 298 {
 299         return crypto_transfer_request_to_engine(engine, &req->base);
 300 }
 301 EXPORT_SYMBOL_GPL(crypto_transfer_aead_request_to_engine);
 302
 303 /**
 304  * crypto_transfer_akcipher_request_to_engine - transfer one akcipher_request
 305  * to list into the engine queue
 306  * @engine: the hardware engine
 307  * @req: the request need to be listed into the engine queue
 308  */
 309 int crypto_transfer_akcipher_request_to_engine(struct crypto_engine *engine,
 310                                                struct akcipher_request *req)
 311 {
 312         return crypto_transfer_request_to_engine(engine, &req->base);
 313 }
 314 EXPORT_SYMBOL_GPL(crypto_transfer_akcipher_request_to_engine);
 315
 316 /**
 317  * crypto_transfer_hash_request_to_engine - transfer one ahash_request
 318  * to list into the engine queue
 319  * @engine: the hardware engine
 320  * @req: the request need to be listed into the engine queue
 321  */
 322 int crypto_transfer_hash_request_to_engine(struct crypto_engine *engine,
 323                                            struct ahash_request *req)
 324 {
 325         return crypto_transfer_request_to_engine(engine, &req->base);
 326 }
 327 EXPORT_SYMBOL_GPL(crypto_transfer_hash_request_to_engine);
 328
 329 /**
 330  * crypto_transfer_skcipher_request_to_engine - transfer one skcipher_request
 331  * to list into the engine queue
 332  * @engine: the hardware engine
 333  * @req: the request need to be listed into the engine queue
 334  */
 335 int crypto_transfer_skcipher_request_to_engine(struct crypto_engine *engine,
 336                                                struct skcipher_request *req)
 337 {
 338         return crypto_transfer_request_to_engine(engine, &req->base);
 339 }
 340 EXPORT_SYMBOL_GPL(crypto_transfer_skcipher_request_to_engine);
 341
 342 /**
 343  * crypto_finalize_aead_request - finalize one aead_request if
 344  * the request is done
 345  * @engine: the hardware engine
 346  * @req: the request need to be finalized
 347  * @err: error number
 348  */
 349 void crypto_finalize_aead_request(struct crypto_engine *engine,
 350                                   struct aead_request *req, int err)
 351 {
 352         return crypto_finalize_request(engine, &req->base, err);
 353 }
 354 EXPORT_SYMBOL_GPL(crypto_finalize_aead_request);
 355
 356 /**
 357  * crypto_finalize_akcipher_request - finalize one akcipher_request if
 358  * the request is done
 359  * @engine: the hardware engine
 360  * @req: the request need to be finalized
 361  * @err: error number
 362  */
 363 void crypto_finalize_akcipher_request(struct crypto_engine *engine,
 364                                       struct akcipher_request *req, int err)
 365 {
 366         return crypto_finalize_request(engine, &req->base, err);
 367 }
 368 EXPORT_SYMBOL_GPL(crypto_finalize_akcipher_request);
 369
 370 /**
 371  * crypto_finalize_hash_request - finalize one ahash_request if
 372  * the request is done
 373  * @engine: the hardware engine
 374  * @req: the request need to be finalized
 375  * @err: error number
 376  */
 377 void crypto_finalize_hash_request(struct crypto_engine *engine,
 378                                   struct ahash_request *req, int err)
 379 {
 380         return crypto_finalize_request(engine, &req->base, err);
 381 }
 382 EXPORT_SYMBOL_GPL(crypto_finalize_hash_request);
 383
 384 /**
 385  * crypto_finalize_skcipher_request - finalize one skcipher_request if
 386  * the request is done
 387  * @engine: the hardware engine
 388  * @req: the request need to be finalized
 389  * @err: error number
 390  */
 391 void crypto_finalize_skcipher_request(struct crypto_engine *engine,
 392                                       struct skcipher_request *req, int err)
 393 {
 394         return crypto_finalize_request(engine, &req->base, err);
 395 }
 396 EXPORT_SYMBOL_GPL(crypto_finalize_skcipher_request);
 397
 398 /**
 399  * crypto_engine_start - start the hardware engine
 400  * @engine: the hardware engine need to be started
 401  *
 402  * Return 0 on success, else on fail.
 403  */
 404 int crypto_engine_start(struct crypto_engine *engine)
 405 {
 406         unsigned long flags;
 407
 408         spin_lock_irqsave(&engine->queue_lock, flags);
 409
 410         if (engine->running || engine->busy) {
 411                 spin_unlock_irqrestore(&engine->queue_lock, flags);
 412                 return -EBUSY;
 413         }
 414
 415         engine->running = true;
 416         spin_unlock_irqrestore(&engine->queue_lock, flags);
 417
 418         kthread_queue_work(engine->kworker, &engine->pump_requests);
 419
 420         return 0;
 421 }
 422 EXPORT_SYMBOL_GPL(crypto_engine_start);
 423
 424 /**
 425  * crypto_engine_stop - stop the hardware engine
 426  * @engine: the hardware engine need to be stopped
 427  *
 428  * Return 0 on success, else on fail.
 429  */
 430 int crypto_engine_stop(struct crypto_engine *engine)
 431 {
 432         unsigned long flags;
 433         unsigned int limit = 500;
 434         int ret = 0;
 435
 436         spin_lock_irqsave(&engine->queue_lock, flags);
 437
 438         /*
 439          * If the engine queue is not empty or the engine is on busy state,
 440          * we need to wait for a while to pump the requests of engine queue.
 441          */
 442         while ((crypto_queue_len(&engine->queue) || engine->busy) && limit--) {
 443                 spin_unlock_irqrestore(&engine->queue_lock, flags);
 444                 msleep(20);
 445                 spin_lock_irqsave(&engine->queue_lock, flags);
 446         }
 447
 448         if (crypto_queue_len(&engine->queue) || engine->busy)
 449                 ret = -EBUSY;
 450         else
 451                 engine->running = false;
 452
 453         spin_unlock_irqrestore(&engine->queue_lock, flags);
 454
 455         if (ret)
 456                 dev_warn(engine->dev, "could not stop engine\n");
 457
 458         return ret;
 459 }
 460 EXPORT_SYMBOL_GPL(crypto_engine_stop);
 461
 462 /**
 463  * crypto_engine_alloc_init_and_set - allocate crypto hardware engine structure
 464  * and initialize it by setting the maximum number of entries in the software
 465  * crypto-engine queue.
 466  * @dev: the device attached with one hardware engine
 467  * @retry_support: whether hardware has support for retry mechanism
 468  * @cbk_do_batch: pointer to a callback function to be invoked when executing a
 469  *                a batch of requests.
 470  *                This has the form:
 471  *                callback(struct crypto_engine *engine)
 472  *                where:
 473  *                @engine: the crypto engine structure.
 474  * @rt: whether this queue is set to run as a realtime task
 475  * @qlen: maximum size of the crypto-engine queue
 476  *
 477  * This must be called from context that can sleep.
 478  * Return: the crypto engine structure on success, else NULL.
 479  */
 480 struct crypto_engine *crypto_engine_alloc_init_and_set(struct device *dev,
 481                                                        bool retry_support,
 482                                                        int (*cbk_do_batch)(struct crypto_engine *engine),
 483                                                        bool rt, int qlen)
 484 {
 485         struct sched_param param = { .sched_priority = MAX_RT_PRIO / 2 };
 486         struct crypto_engine *engine;
 487
 488         if (!dev)
 489                 return NULL;
 490
 491         engine = devm_kzalloc(dev, sizeof(*engine), GFP_KERNEL);
 492         if (!engine)
 493                 return NULL;
 494
 495         engine->dev = dev;
 496         engine->rt = rt;
 497         engine->running = false;
 498         engine->busy = false;
 499         engine->idling = false;
 500         engine->retry_support = retry_support;
 501         engine->priv_data = dev;
 502         /*
 503          * Batch requests is possible only if
 504          * hardware has support for retry mechanism.
 505          */
 506         engine->do_batch_requests = retry_support ? cbk_do_batch : NULL;
 507
 508         snprintf(engine->name, sizeof(engine->name),
 509                  "%s-engine", dev_name(dev));
 510
 511         crypto_init_queue(&engine->queue, qlen);
 512         spin_lock_init(&engine->queue_lock);
 513
 514         engine->kworker = kthread_create_worker(0, "%s", engine->name);
 515         if (IS_ERR(engine->kworker)) {
 516                 dev_err(dev, "failed to create crypto request pump task\n");
 517                 return NULL;
 518         }
 519         kthread_init_work(&engine->pump_requests, crypto_pump_work);
 520
 521         if (engine->rt) {
 522                 dev_info(dev, "will run requests pump with realtime priority\n");
 523                 sched_setscheduler(engine->kworker->task, SCHED_FIFO, &param);
 524         }
 525
 526         return engine;
 527 }
 528 EXPORT_SYMBOL_GPL(crypto_engine_alloc_init_and_set);
 529
 530 /**
 531  * crypto_engine_alloc_init - allocate crypto hardware engine structure and
 532  * initialize it.
 533  * @dev: the device attached with one hardware engine
 534  * @rt: whether this queue is set to run as a realtime task
 535  *
 536  * This must be called from context that can sleep.
 537  * Return: the crypto engine structure on success, else NULL.
 538  */
 539 struct crypto_engine *crypto_engine_alloc_init(struct device *dev, bool rt)
 540 {
 541         return crypto_engine_alloc_init_and_set(dev, false, NULL, rt,
 542                                                 CRYPTO_ENGINE_MAX_QLEN);
 543 }
 544 EXPORT_SYMBOL_GPL(crypto_engine_alloc_init);
 545
 546 /**
 547  * crypto_engine_exit - free the resources of hardware engine when exit
 548  * @engine: the hardware engine need to be freed
 549  *
 550  * Return 0 for success.
 551  */
 552 int crypto_engine_exit(struct crypto_engine *engine)
 553 {
 554         int ret;
 555
 556         ret = crypto_engine_stop(engine);
 557         if (ret)
 558                 return ret;
 559
 560         kthread_destroy_worker(engine->kworker);
 561
 562         return 0;
 563 }
 564 EXPORT_SYMBOL_GPL(crypto_engine_exit);
 565
 566 MODULE_LICENSE("GPL");
 567 MODULE_DESCRIPTION("Crypto hardware engine framework");