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