Introduce virtqueue_reset() to release all buffer inside vq.
Signed-off-by: Xuan Zhuo <xuanzhuo@xxxxxxxxxxxxxxxxx>
---
drivers/virtio/virtio_ring.c | 50 ++++++++++++++++++++++++++++++++++++
include/linux/virtio.h | 2 ++
2 files changed, 52 insertions(+)
diff --git a/drivers/virtio/virtio_ring.c b/drivers/virtio/virtio_ring.c
index 2ba60a14f557..2750a365439a 100644
--- a/drivers/virtio/virtio_ring.c
+++ b/drivers/virtio/virtio_ring.c
@@ -2930,6 +2930,56 @@ int virtqueue_resize(struct virtqueue *_vq, u32 num,
}
EXPORT_SYMBOL_GPL(virtqueue_resize);
+/**
+ * virtqueue_reset - detach and recycle all unused buffers
+ * @_vq: the struct virtqueue we're talking about.
+ * @recycle: callback to recycle unused buffers
+ *
+ * Caller must ensure we don't call this with other virtqueue operations
+ * at the same time (except where noted).
+ *
+ * Returns zero or a negative error.
+ * 0: success.
+ * -EBUSY: Failed to sync with device, vq may not work properly
+ * -ENOENT: Transport or device not supported
+ * -EPERM: Operation not permitted
+ */
+int virtqueue_reset(struct virtqueue *_vq,
+ void (*recycle)(struct virtqueue *vq, void *buf))
+{
+ struct vring_virtqueue *vq = to_vvq(_vq);
+ struct virtio_device *vdev = vq->vq.vdev;
+ void *buf;
+ int err;
+
+ if (!vq->we_own_ring)
+ return -EPERM;
+
+ if (!vdev->config->disable_vq_and_reset)
+ return -ENOENT;
+
+ if (!vdev->config->enable_vq_after_reset)
+ return -ENOENT;
+
+ err = vdev->config->disable_vq_and_reset(_vq);
+ if (err)
+ return err;
+
+ while ((buf = virtqueue_detach_unused_buf(_vq)) != NULL)
+ recycle(_vq, buf);
+
+ if (vq->packed_ring)
+ virtqueue_reinit_packed(vq);
+ else
+ virtqueue_reinit_split(vq);
+
+ if (vdev->config->enable_vq_after_reset(_vq))
+ return -EBUSY;
+
+ return 0;
+}
+EXPORT_SYMBOL_GPL(virtqueue_reset);
+
/* Only available for split ring */
struct virtqueue *vring_new_virtqueue(unsigned int index,
unsigned int num,
diff --git a/include/linux/virtio.h b/include/linux/virtio.h
index d0e707d744a0..cf4c157e4e75 100644
--- a/include/linux/virtio.h
+++ b/include/linux/virtio.h
@@ -106,6 +106,8 @@ dma_addr_t virtqueue_get_used_addr(struct virtqueue *vq);
int virtqueue_resize(struct virtqueue *vq, u32 num,
void (*recycle)(struct virtqueue *vq, void *buf));
+int virtqueue_reset(struct virtqueue *vq,
+ void (*recycle)(struct virtqueue *vq, void *buf));
/**
* struct virtio_device - representation of a device using virtio
--
2.32.0.3.g01195cf9f
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