crypto/crypto_engine.c

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