crypto: virtio - Handle dataq logic with tasklet

Doing ipsec produces a spinlock recursion warning.
This is due to crypto_finalize_request() being called in the upper half.
Move virtual data queue processing of virtio-crypto driver to tasklet.

Fixes: dbaf0624ffa57 ("crypto: add virtio-crypto driver")
Reported-by: Halil Pasic <[e-mail]>
Signed-off-by: wangyangxin <[e-mail]>
Signed-off-by: Gonglei <[e-mail]>
Signed-off-by: Herbert Xu <[e-mail]>

drivers/crypto/virtio/virtio_crypto_common.h

···
 #include <linux/virtio.h>
 #include <linux/crypto.h>
 #include <linux/spinlock.h>
+#include <linux/interrupt.h>
 #include <crypto/aead.h>
 #include <crypto/aes.h>
 #include <crypto/engine.h>
···
 	char name[32];
 
 	struct crypto_engine *engine;
+	struct tasklet_struct done_task;
 };
 
 struct virtio_crypto {

drivers/crypto/virtio/virtio_crypto_core.c

···
 	return 0;
 }
 
-static void virtcrypto_dataq_callback(struct virtqueue *vq)
+static void virtcrypto_done_task(unsigned long data)
 {
-	struct virtio_crypto *vcrypto = vq->vdev->priv;
+	struct data_queue *data_vq = (struct data_queue *)data;
+	struct virtqueue *vq = data_vq->vq;
 	struct virtio_crypto_request *vc_req;
-	unsigned long flags;
 	unsigned int len;
-	unsigned int qid = vq->index;
 
-	spin_lock_irqsave(&vcrypto->data_vq[qid].lock, flags);
 	do {
 		virtqueue_disable_cb(vq);
 		while ((vc_req = virtqueue_get_buf(vq, &len)) != NULL) {
-			spin_unlock_irqrestore(
-				&vcrypto->data_vq[qid].lock, flags);
 			if (vc_req->alg_cb)
 				vc_req->alg_cb(vc_req, len);
-			spin_lock_irqsave(
-				&vcrypto->data_vq[qid].lock, flags);
 		}
 	} while (!virtqueue_enable_cb(vq));
-	spin_unlock_irqrestore(&vcrypto->data_vq[qid].lock, flags);
+}
+
+static void virtcrypto_dataq_callback(struct virtqueue *vq)
+{
+	struct virtio_crypto *vcrypto = vq->vdev->priv;
+	struct data_queue *dq = &vcrypto->data_vq[vq->index];
+
+	tasklet_schedule(&dq->done_task);
 }
 
 static int virtcrypto_find_vqs(struct virtio_crypto *vi)
···
 			ret = -ENOMEM;
 			goto err_engine;
 		}
+		tasklet_init(&vi->data_vq[i].done_task, virtcrypto_done_task,
+				(unsigned long)&vi->data_vq[i]);
 	}
 
 	kfree(names);