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>

crypto/crypto_engine.c

@@ -227,6 +227,18 @@ retry:
 
 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);

include/crypto/engine.h

@@ -37,6 +37,8 @@
  * @unprepare_crypt_hardware: there are currently no more requests on the
  * queue so the subsystem notifies the driver that it may relax the
  * hardware by issuing this call
+ * @do_batch_requests: execute a batch of requests. Depends on multiple
+ * requests support.
  * @kworker: kthread worker struct for request pump
  * @pump_requests: work struct for scheduling work to the request pump
  * @priv_data: the engine private data
@@ -59,6 +61,8 @@ struct crypto_engine {
 
 	int (*prepare_crypt_hardware)(struct crypto_engine *engine);
 	int (*unprepare_crypt_hardware)(struct crypto_engine *engine);
+	int (*do_batch_requests)(struct crypto_engine *engine);
+
 
 	struct kthread_worker           *kworker;
 	struct kthread_work             pump_requests;
@@ -107,6 +111,7 @@ int crypto_engine_stop(struct crypto_engine *engine);
 struct crypto_engine *crypto_engine_alloc_init(struct device *dev, bool rt);
 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);
 int crypto_engine_exit(struct crypto_engine *engine);