crypto: engine - support for batch requests

Added support for batch requests, per crypto engine.
A new callback is added, do_batch_requests, which executes a
batch of requests. This has the crypto_engine structure as argument
(for cases when more than one crypto-engine is used).
The crypto_engine_alloc_init_and_set function, initializes
crypto-engine, but also, sets the do_batch_requests callback.
On crypto_pump_requests, if do_batch_requests callback is
implemented in a driver, this will be executed. The link between
the requests will be done in driver, if possible.
do_batch_requests is available only if the hardware has support
for multiple request.

Signed-off-by: Iuliana Prodan <iuliana.prodan@nxp.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
diff --git a/crypto/crypto_engine.c b/crypto/crypto_engine.c
index ee19273..412149e 100644
--- a/crypto/crypto_engine.c
+++ b/crypto/crypto_engine.c
@@ -227,6 +227,18 @@ static void crypto_pump_requests(struct crypto_engine *engine,
 
 out:
 	spin_unlock_irqrestore(&engine->queue_lock, flags);
+
+	/*
+	 * Batch requests is possible only if
+	 * hardware can enqueue multiple requests
+	 */
+	if (engine->do_batch_requests) {
+		ret = engine->do_batch_requests(engine);
+		if (ret)
+			dev_err(engine->dev, "failed to do batch requests: %d\n",
+				ret);
+	}
+
 	return;
 }
 
@@ -456,6 +468,12 @@ EXPORT_SYMBOL_GPL(crypto_engine_stop);
  * crypto-engine queue.
  * @dev: the device attached with one hardware engine
  * @retry_support: whether hardware has support for retry mechanism
+ * @cbk_do_batch: pointer to a callback function to be invoked when executing a
+ *                a batch of requests.
+ *                This has the form:
+ *                callback(struct crypto_engine *engine)
+ *                where:
+ *                @engine: the crypto engine structure.
  * @rt: whether this queue is set to run as a realtime task
  * @qlen: maximum size of the crypto-engine queue
  *
@@ -464,6 +482,7 @@ EXPORT_SYMBOL_GPL(crypto_engine_stop);
  */
 struct crypto_engine *crypto_engine_alloc_init_and_set(struct device *dev,
 						       bool retry_support,
+						       int (*cbk_do_batch)(struct crypto_engine *engine),
 						       bool rt, int qlen)
 {
 	struct sched_param param = { .sched_priority = MAX_RT_PRIO / 2 };
@@ -483,6 +502,12 @@ struct crypto_engine *crypto_engine_alloc_init_and_set(struct device *dev,
 	engine->idling = false;
 	engine->retry_support = retry_support;
 	engine->priv_data = dev;
+	/*
+	 * Batch requests is possible only if
+	 * hardware has support for retry mechanism.
+	 */
+	engine->do_batch_requests = retry_support ? cbk_do_batch : NULL;
+
 	snprintf(engine->name, sizeof(engine->name),
 		 "%s-engine", dev_name(dev));
 
@@ -516,7 +541,7 @@ EXPORT_SYMBOL_GPL(crypto_engine_alloc_init_and_set);
  */
 struct crypto_engine *crypto_engine_alloc_init(struct device *dev, bool rt)
 {
-	return crypto_engine_alloc_init_and_set(dev, false, rt,
+	return crypto_engine_alloc_init_and_set(dev, false, NULL, rt,
 						CRYPTO_ENGINE_MAX_QLEN);
 }
 EXPORT_SYMBOL_GPL(crypto_engine_alloc_init);