[PATCH v2] crypto: virtio-crypto: Handle dataq logic with tasklet

[Gonglei (Arei)]

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: dbaf0624ffa5 ("crypto: add virtio-crypto driver")
Reported-by: Halil Pasic <pa...@linux.ibm.com>
Signed-off-by: wangyangxin <wangyangx...@huawei.com>
Signed-off-by: Gonglei <arei.gong...@huawei.com>
---
 v2: calling tasklet_kill() in virtcrypto_remove(), thanks for MST.

 drivers/crypto/virtio/virtio_crypto_common.h |  2 ++
 drivers/crypto/virtio/virtio_crypto_core.c   | 26 ++++++++++++++++----------
 2 files changed, 18 insertions(+), 10 deletions(-)

diff --git a/drivers/crypto/virtio/virtio_crypto_common.h 
b/drivers/crypto/virtio/virtio_crypto_common.h
index 154590e..7059bbe 100644
--- a/drivers/crypto/virtio/virtio_crypto_common.h
+++ b/drivers/crypto/virtio/virtio_crypto_common.h
@@ -10,6 +10,7 @@
 #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>
@@ -28,6 +29,7 @@ struct data_queue {
        char name[32];
 
        struct crypto_engine *engine;
+       struct tasklet_struct done_task;
 };
 
 struct virtio_crypto {
diff --git a/drivers/crypto/virtio/virtio_crypto_core.c 
b/drivers/crypto/virtio/virtio_crypto_core.c
index 43a0838..b909c6a 100644
--- a/drivers/crypto/virtio/virtio_crypto_core.c
+++ b/drivers/crypto/virtio/virtio_crypto_core.c
@@ -72,27 +72,28 @@ int virtio_crypto_ctrl_vq_request(struct virtio_crypto 
*vcrypto, struct scatterl
        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)
@@ -150,6 +151,8 @@ 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);
@@ -497,12 +500,15 @@ static void virtcrypto_free_unused_reqs(struct 
virtio_crypto *vcrypto)
 static void virtcrypto_remove(struct virtio_device *vdev)
 {
        struct virtio_crypto *vcrypto = vdev->priv;
+       int i;
 
        dev_info(&vdev->dev, "Start virtcrypto_remove.\n");
 
        flush_work(&vcrypto->config_work);
        if (virtcrypto_dev_started(vcrypto))
                virtcrypto_dev_stop(vcrypto);
+       for (i = 0; i < vcrypto->max_data_queues; i++)
+               tasklet_kill(&vcrypto->data_vq[i].done_task);
        virtio_reset_device(vdev);
        virtcrypto_free_unused_reqs(vcrypto);
        virtcrypto_clear_crypto_engines(vcrypto);
-- 
1.8.3.1