crypto: engine - remove request batching support

Remove request batching support from crypto_engine, as there are no
drivers using this feature and it doesn't really work that well.

Instead of doing batching based on backlog, a more optimal approach
would be for the user to handle the batching (similar to how IPsec
can hook into GSO to get 64K of data each time or how block encryption
can use unit sizes much greater than 4K).

Suggested-by: Herbert Xu <[e-mail]>
Signed-off-by: Ovidiu Panait <[e-mail]>
Reviewed-by: Horia Geantă <[e-mail]>
Signed-off-by: Herbert Xu <[e-mail]>

arch/s390/crypto/paes_s390.c

···
 	/* with this pseudo devie alloc and start a crypto engine */
 	paes_crypto_engine =
 		crypto_engine_alloc_init_and_set(paes_dev.this_device,
-						 true, NULL, false, MAX_QLEN);
+						 true, false, MAX_QLEN);
 	if (!paes_crypto_engine) {
 		rc = -ENOMEM;
 		goto out_err;

arch/s390/crypto/phmac_s390.c

···
 	/* with this pseudo device alloc and start a crypto engine */
 	phmac_crypto_engine =
 		crypto_engine_alloc_init_and_set(phmac_dev.this_device,
-						 true, NULL, false, MAX_QLEN);
+						 true, false, MAX_QLEN);
 	if (!phmac_crypto_engine) {
 		rc = -ENOMEM;
 		goto out_err;

crypto/crypto_engine.c

···
 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;
 }
 
···
  * 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 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
  *
···
  */
 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 crypto_engine *engine;
···
 	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));
···
  */
 struct crypto_engine *crypto_engine_alloc_init(struct device *dev, bool rt)
 {
-	return crypto_engine_alloc_init_and_set(dev, false, NULL, rt,
+	return crypto_engine_alloc_init_and_set(dev, false, rt,
 						CRYPTO_ENGINE_MAX_QLEN);
 }
 EXPORT_SYMBOL_GPL(crypto_engine_alloc_init);

drivers/crypto/caam/jr.c

···
 	}
 
 	/* Initialize crypto engine */
-	jrpriv->engine = crypto_engine_alloc_init_and_set(jrdev, true, NULL,
-							  false,
+	jrpriv->engine = crypto_engine_alloc_init_and_set(jrdev, true, false,
 							  CRYPTO_ENGINE_MAX_QLEN);
 	if (!jrpriv->engine) {
 		dev_err(jrdev, "Could not init crypto-engine\n");

drivers/crypto/virtio/virtio_crypto_core.c

···
 		spin_lock_init(&vi->data_vq[i].lock);
 		vi->data_vq[i].vq = vqs[i];
 		/* Initialize crypto engine */
-		vi->data_vq[i].engine = crypto_engine_alloc_init_and_set(dev, true, NULL, true,
+		vi->data_vq[i].engine = crypto_engine_alloc_init_and_set(dev, true, true,
 						virtqueue_get_vring_size(vqs[i]));
 		if (!vi->data_vq[i].engine) {
 			ret = -ENOMEM;

include/crypto/engine.h

···
 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);
 void crypto_engine_exit(struct crypto_engine *engine);
 

include/crypto/internal/engine.h

···
  * @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
···
 
 	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;