virtio-gpu: add locking for vbuf pool

Signed-off-by: Dave Airlie <airlied@redhat.com>
Signed-off-by: Gerd Hoffmann <kraxel@redhat.com>

2 files changed, 8 insertions, 0 deletions

diff --git a/drivers/gpu/drm/virtio/virtgpu_drv.h b/drivers/gpu/drm/virtio/virtgpu_drv.h
index ff8de3d6f0b2..6d4db2dba90b 100644
--- a/drivers/gpu/drm/virtio/virtgpu_drv.h
+++ b/drivers/gpu/drm/virtio/virtgpu_drv.h
@@ -162,6 +162,7 @@ struct virtio_gpu_device {
         struct virtio_gpu_queue ctrlq;
         struct virtio_gpu_queue cursorq;
         struct list_head free_vbufs;
+        spinlock_t free_vbufs_lock;
         void *vbufs;
         bool vqs_ready;
 
diff --git a/drivers/gpu/drm/virtio/virtgpu_vq.c b/drivers/gpu/drm/virtio/virtgpu_vq.c
index c5067926401f..1698669f4185 100644
--- a/drivers/gpu/drm/virtio/virtgpu_vq.c
+++ b/drivers/gpu/drm/virtio/virtgpu_vq.c
@@ -79,6 +79,7 @@ int virtio_gpu_alloc_vbufs(struct virtio_gpu_device *vgdev)
         void *ptr;
 
         INIT_LIST_HEAD(&vgdev->free_vbufs);
+        spin_lock_init(&vgdev->free_vbufs_lock);
         count += virtqueue_get_vring_size(vgdev->ctrlq.vq);
         count += virtqueue_get_vring_size(vgdev->cursorq.vq);
         size = count * VBUFFER_SIZE;
@@ -106,6 +107,7 @@ void virtio_gpu_free_vbufs(struct virtio_gpu_device *vgdev)
         count += virtqueue_get_vring_size(vgdev->ctrlq.vq);
         count += virtqueue_get_vring_size(vgdev->cursorq.vq);
 
+        spin_lock(&vgdev->free_vbufs_lock);
         for (i = 0; i < count; i++) {
                 if (WARN_ON(list_empty(&vgdev->free_vbufs)))
                         return;
@@ -113,6 +115,7 @@ void virtio_gpu_free_vbufs(struct virtio_gpu_device *vgdev)
                                         struct virtio_gpu_vbuffer, list);
                 list_del(&vbuf->list);
         }
+        spin_unlock(&vgdev->free_vbufs_lock);
         kfree(vgdev->vbufs);
 }
 
@@ -123,10 +126,12 @@ virtio_gpu_get_vbuf(struct virtio_gpu_device *vgdev,
 {
         struct virtio_gpu_vbuffer *vbuf;
 
+        spin_lock(&vgdev->free_vbufs_lock);
         BUG_ON(list_empty(&vgdev->free_vbufs));
         vbuf = list_first_entry(&vgdev->free_vbufs,
                                 struct virtio_gpu_vbuffer, list);
         list_del(&vbuf->list);
+        spin_unlock(&vgdev->free_vbufs_lock);
         memset(vbuf, 0, VBUFFER_SIZE);
 
         BUG_ON(size > MAX_INLINE_CMD_SIZE);
@@ -201,7 +206,9 @@ static void free_vbuf(struct virtio_gpu_device *vgdev,
         if (vbuf->resp_size > MAX_INLINE_RESP_SIZE)
                 kfree(vbuf->resp_buf);
         kfree(vbuf->data_buf);
+        spin_lock(&vgdev->free_vbufs_lock);
         list_add(&vbuf->list, &vgdev->free_vbufs);
+        spin_unlock(&vgdev->free_vbufs_lock);
 }
 
 static void reclaim_vbufs(struct virtqueue *vq, struct list_head *reclaim_list)