crypto/crypto_engine.c - kernel/common - Git at Google

 /*
  * Handle async block request by crypto hardware engine.
  *
  * Copyright (C) 2016 Linaro, Inc.
  *
  * Author: Baolin Wang <[email protected]>
  *
  * This program is free software; you can redistribute it and/or modify it
  * under the terms of the GNU General Public License as published by the Free
  * Software Foundation; either version 2 of the License, or (at your option)
  * any later version.
  *
  */

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

 #define CRYPTO_ENGINE_MAX_QLEN 10

 /**
  * 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;
 	struct ahash_request *hreq;
 	struct ablkcipher_request *breq;
 	unsigned long flags;
 	bool was_busy = false;
 	int ret, rtype;

 	spin_lock_irqsave(&engine->queue_lock, flags);

 	/* Make sure we are not already running a request */
 	if (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;
 	}

 	/* 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;

 	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);

 	rtype = crypto_tfm_alg_type(engine->cur_req->tfm);
 	/* 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;
 		}
 	}

 	switch (rtype) {
 	case CRYPTO_ALG_TYPE_AHASH:
 		hreq = ahash_request_cast(engine->cur_req);
 		if (engine->prepare_hash_request) {
 			ret = engine->prepare_hash_request(engine, hreq);
 			if (ret) {
 				dev_err(engine->dev, "failed to prepare request: %d\n",
 					ret);
 				goto req_err;
 			}
 			engine->cur_req_prepared = true;
 		}
 		ret = engine->hash_one_request(engine, hreq);
 		if (ret) {
 			dev_err(engine->dev, "failed to hash one request from queue\n");
 			goto req_err;
 		}
 		return;
 	case CRYPTO_ALG_TYPE_ABLKCIPHER:
 		breq = ablkcipher_request_cast(engine->cur_req);
 		if (engine->prepare_cipher_request) {
 			ret = engine->prepare_cipher_request(engine, breq);
 			if (ret) {
 				dev_err(engine->dev, "failed to prepare request: %d\n",
 					ret);
 				goto req_err;
 			}
 			engine->cur_req_prepared = true;
 		}
 		ret = engine->cipher_one_request(engine, breq);
 		if (ret) {
 			dev_err(engine->dev, "failed to cipher one request from queue\n");
 			goto req_err;
 		}
 		return;
 	default:
 		dev_err(engine->dev, "failed to prepare request of unknown type\n");
 		return;
 	}

 req_err:
 	switch (rtype) {
 	case CRYPTO_ALG_TYPE_AHASH:
 		hreq = ahash_request_cast(engine->cur_req);
 		crypto_finalize_hash_request(engine, hreq, ret);
 		break;
 	case CRYPTO_ALG_TYPE_ABLKCIPHER:
 		breq = ablkcipher_request_cast(engine->cur_req);
 		crypto_finalize_cipher_request(engine, breq, ret);
 		break;
 	}
 	return;

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

 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_cipher_request - transfer the new request into the
  * enginequeue
  * @engine: the hardware engine
  * @req: the request need to be listed into the engine queue
  */
 int crypto_transfer_cipher_request(struct crypto_engine *engine,
 				   struct ablkcipher_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 = ablkcipher_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;
 }
 EXPORT_SYMBOL_GPL(crypto_transfer_cipher_request);

 /**
  * crypto_transfer_cipher_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
  */
 int crypto_transfer_cipher_request_to_engine(struct crypto_engine *engine,
 					     struct ablkcipher_request *req)
 {
 	return crypto_transfer_cipher_request(engine, req, true);
 }
 EXPORT_SYMBOL_GPL(crypto_transfer_cipher_request_to_engine);

 /**
  * crypto_transfer_hash_request - transfer the new request into the
  * enginequeue
  * @engine: the hardware engine
  * @req: the request need to be listed into the engine queue
  */
 int crypto_transfer_hash_request(struct crypto_engine *engine,
 				 struct ahash_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 = ahash_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;
 }
 EXPORT_SYMBOL_GPL(crypto_transfer_hash_request);

 /**
  * crypto_transfer_hash_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
  */
 int crypto_transfer_hash_request_to_engine(struct crypto_engine *engine,
 					   struct ahash_request *req)
 {
 	return crypto_transfer_hash_request(engine, req, true);
 }
 EXPORT_SYMBOL_GPL(crypto_transfer_hash_request_to_engine);

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

 	spin_lock_irqsave(&engine->queue_lock, flags);
 	if (engine->cur_req == &req->base)
 		finalize_cur_req = true;
 	spin_unlock_irqrestore(&engine->queue_lock, flags);

 	if (finalize_cur_req) {
 		if (engine->cur_req_prepared &&
 		    engine->unprepare_cipher_request) {
 			ret = engine->unprepare_cipher_request(engine, req);
 			if (ret)
 				dev_err(engine->dev, "failed to unprepare request\n");
 		}
 		spin_lock_irqsave(&engine->queue_lock, flags);
 		engine->cur_req = NULL;
 		engine->cur_req_prepared = false;
 		spin_unlock_irqrestore(&engine->queue_lock, flags);
 	}

 	req->base.complete(&req->base, err);

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

 /**
  * crypto_finalize_hash_request - finalize one 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)
 {
 	unsigned long flags;
 	bool finalize_cur_req = false;
 	int ret;

 	spin_lock_irqsave(&engine->queue_lock, flags);
 	if (engine->cur_req == &req->base)
 		finalize_cur_req = true;
 	spin_unlock_irqrestore(&engine->queue_lock, flags);

 	if (finalize_cur_req) {
 		if (engine->cur_req_prepared &&
 		    engine->unprepare_hash_request) {
 			ret = engine->unprepare_hash_request(engine, req);
 			if (ret)
 				dev_err(engine->dev, "failed to unprepare request\n");
 		}
 		spin_lock_irqsave(&engine->queue_lock, flags);
 		engine->cur_req = NULL;
 		engine->cur_req_prepared = false;
 		spin_unlock_irqrestore(&engine->queue_lock, flags);
 	}

 	req->base.complete(&req->base, err);

 	kthread_queue_work(engine->kworker, &engine->pump_requests);
 }
 EXPORT_SYMBOL_GPL(crypto_finalize_hash_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 - 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)
 {
 	struct sched_param param = { .sched_priority = MAX_RT_PRIO - 1 };
 	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->cur_req_prepared = false;
 	engine->priv_data = dev;
 	snprintf(engine->name, sizeof(engine->name),
 		 "%s-engine", dev_name(dev));

 	crypto_init_queue(&engine->queue, CRYPTO_ENGINE_MAX_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);

 /**
  * 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");
	/*
	* Handle async block request by crypto hardware engine.
	*
	* Copyright (C) 2016 Linaro, Inc.
	*
	* Author: Baolin Wang <[email protected]>
	*
	* This program is free software; you can redistribute it and/or modify it
	* under the terms of the GNU General Public License as published by the Free
	* Software Foundation; either version 2 of the License, or (at your option)
	* any later version.
	*
	*/

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

	#define CRYPTO_ENGINE_MAX_QLEN 10

	/**
	* 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;
	struct ahash_request *hreq;
	struct ablkcipher_request *breq;
	unsigned long flags;
	bool was_busy = false;
	int ret, rtype;

	spin_lock_irqsave(&engine->queue_lock, flags);

	/* Make sure we are not already running a request */
	if (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;
	}

	/* 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;

	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);

	rtype = crypto_tfm_alg_type(engine->cur_req->tfm);
	/* 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;
	}
	}

	switch (rtype) {
	case CRYPTO_ALG_TYPE_AHASH:
	hreq = ahash_request_cast(engine->cur_req);
	if (engine->prepare_hash_request) {
	ret = engine->prepare_hash_request(engine, hreq);
	if (ret) {
	dev_err(engine->dev, "failed to prepare request: %d\n",
	ret);
	goto req_err;
	}
	engine->cur_req_prepared = true;
	}
	ret = engine->hash_one_request(engine, hreq);
	if (ret) {
	dev_err(engine->dev, "failed to hash one request from queue\n");
	goto req_err;
	}
	return;
	case CRYPTO_ALG_TYPE_ABLKCIPHER:
	breq = ablkcipher_request_cast(engine->cur_req);
	if (engine->prepare_cipher_request) {
	ret = engine->prepare_cipher_request(engine, breq);
	if (ret) {
	dev_err(engine->dev, "failed to prepare request: %d\n",
	ret);
	goto req_err;
	}
	engine->cur_req_prepared = true;
	}
	ret = engine->cipher_one_request(engine, breq);
	if (ret) {
	dev_err(engine->dev, "failed to cipher one request from queue\n");
	goto req_err;
	}
	return;
	default:
	dev_err(engine->dev, "failed to prepare request of unknown type\n");
	return;
	}

	req_err:
	switch (rtype) {
	case CRYPTO_ALG_TYPE_AHASH:
	hreq = ahash_request_cast(engine->cur_req);
	crypto_finalize_hash_request(engine, hreq, ret);
	break;
	case CRYPTO_ALG_TYPE_ABLKCIPHER:
	breq = ablkcipher_request_cast(engine->cur_req);
	crypto_finalize_cipher_request(engine, breq, ret);
	break;
	}
	return;

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

	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_cipher_request - transfer the new request into the
	* enginequeue
	* @engine: the hardware engine
	* @req: the request need to be listed into the engine queue
	*/
	int crypto_transfer_cipher_request(struct crypto_engine *engine,
	struct ablkcipher_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 = ablkcipher_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;
	}
	EXPORT_SYMBOL_GPL(crypto_transfer_cipher_request);

	/**
	* crypto_transfer_cipher_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
	*/
	int crypto_transfer_cipher_request_to_engine(struct crypto_engine *engine,
	struct ablkcipher_request *req)
	{
	return crypto_transfer_cipher_request(engine, req, true);
	}
	EXPORT_SYMBOL_GPL(crypto_transfer_cipher_request_to_engine);

	/**
	* crypto_transfer_hash_request - transfer the new request into the
	* enginequeue
	* @engine: the hardware engine
	* @req: the request need to be listed into the engine queue
	*/
	int crypto_transfer_hash_request(struct crypto_engine *engine,
	struct ahash_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 = ahash_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;
	}
	EXPORT_SYMBOL_GPL(crypto_transfer_hash_request);

	/**
	* crypto_transfer_hash_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
	*/
	int crypto_transfer_hash_request_to_engine(struct crypto_engine *engine,
	struct ahash_request *req)
	{
	return crypto_transfer_hash_request(engine, req, true);
	}
	EXPORT_SYMBOL_GPL(crypto_transfer_hash_request_to_engine);

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

	spin_lock_irqsave(&engine->queue_lock, flags);
	if (engine->cur_req == &req->base)
	finalize_cur_req = true;
	spin_unlock_irqrestore(&engine->queue_lock, flags);

	if (finalize_cur_req) {
	if (engine->cur_req_prepared &&
	engine->unprepare_cipher_request) {
	ret = engine->unprepare_cipher_request(engine, req);
	if (ret)
	dev_err(engine->dev, "failed to unprepare request\n");
	}
	spin_lock_irqsave(&engine->queue_lock, flags);
	engine->cur_req = NULL;
	engine->cur_req_prepared = false;
	spin_unlock_irqrestore(&engine->queue_lock, flags);
	}

	req->base.complete(&req->base, err);

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

	/**
	* crypto_finalize_hash_request - finalize one 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)
	{
	unsigned long flags;
	bool finalize_cur_req = false;
	int ret;

	spin_lock_irqsave(&engine->queue_lock, flags);
	if (engine->cur_req == &req->base)
	finalize_cur_req = true;
	spin_unlock_irqrestore(&engine->queue_lock, flags);

	if (finalize_cur_req) {
	if (engine->cur_req_prepared &&
	engine->unprepare_hash_request) {
	ret = engine->unprepare_hash_request(engine, req);
	if (ret)
	dev_err(engine->dev, "failed to unprepare request\n");
	}
	spin_lock_irqsave(&engine->queue_lock, flags);
	engine->cur_req = NULL;
	engine->cur_req_prepared = false;
	spin_unlock_irqrestore(&engine->queue_lock, flags);
	}

	req->base.complete(&req->base, err);

	kthread_queue_work(engine->kworker, &engine->pump_requests);
	}
	EXPORT_SYMBOL_GPL(crypto_finalize_hash_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 - 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)
	{
	struct sched_param param = { .sched_priority = MAX_RT_PRIO - 1 };
	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->cur_req_prepared = false;
	engine->priv_data = dev;
	snprintf(engine->name, sizeof(engine->name),
	"%s-engine", dev_name(dev));

	crypto_init_queue(&engine->queue, CRYPTO_ENGINE_MAX_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);

	/**
	* 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");