Commit 5a222421 authored by Jason Wang's avatar Jason Wang Committed by Michael S. Tsirkin
Browse files

virtio-ring: factor out desc_extra allocation 



A helper is introduced for the logic of allocating the descriptor
extra data. This will be reused by split virtqueue.

Signed-off-by: default avatarJason Wang <jasowang@redhat.com>
Link: https://lore.kernel.org/r/20210604055350.58753-4-jasowang@redhat.com


Signed-off-by: default avatarMichael S. Tsirkin <mst@redhat.com>
parent 1f28750f

drivers/virtio/virtio_ring.c

+20 −10
Original line number Diff line number Diff line
@@ -1556,6 +1556,25 @@ static void *virtqueue_detach_unused_buf_packed(struct virtqueue *_vq) 
	return NULL;

}



static struct vring_desc_extra *vring_alloc_desc_extra(struct vring_virtqueue *vq,

						       unsigned int num)

{

	struct vring_desc_extra *desc_extra;

	unsigned int i;



	desc_extra = kmalloc_array(num, sizeof(struct vring_desc_extra),

				   GFP_KERNEL);

	if (!desc_extra)

		return NULL;



	memset(desc_extra, 0, num * sizeof(struct vring_desc_extra));



	for (i = 0; i < num - 1; i++)

		desc_extra[i].next = i + 1;



	return desc_extra;

}



static struct virtqueue *vring_create_virtqueue_packed(

	unsigned int index,

	unsigned int num,
@@ -1573,7 +1592,6 @@ static struct virtqueue *vring_create_virtqueue_packed( 
	struct vring_packed_desc_event *driver, *device;

	dma_addr_t ring_dma_addr, driver_event_dma_addr, device_event_dma_addr;

	size_t ring_size_in_bytes, event_size_in_bytes;

	unsigned int i;



	ring_size_in_bytes = num * sizeof(struct vring_packed_desc);
@@ -1657,18 +1675,10 @@ static struct virtqueue *vring_create_virtqueue_packed( 
	/* Put everything in free lists. */

	vq->free_head = 0;



	vq->packed.desc_extra = kmalloc_array(num,

			sizeof(struct vring_desc_extra),

			GFP_KERNEL);

	vq->packed.desc_extra = vring_alloc_desc_extra(vq, num);

	if (!vq->packed.desc_extra)

		goto err_desc_extra;



	memset(vq->packed.desc_extra, 0,

		num * sizeof(struct vring_desc_extra));



	for (i = 0; i < num - 1; i++)

		vq->packed.desc_extra[i].next = i + 1;



	/* No callback?  Tell other side not to bother us. */

	if (!callback) {

		vq->packed.event_flags_shadow = VRING_PACKED_EVENT_FLAG_DISABLE;