Commit 46e20d43 authored by Juergen Gross's avatar Juergen Gross
Browse files

xen/netfront: use xenbus_setup_ring() and xenbus_teardown_ring() 



Simplify netfront's ring creation and removal via xenbus_setup_ring()
and xenbus_teardown_ring().

Signed-off-by: default avatarJuergen Gross <jgross@suse.com>
Reviewed-by: default avatarBoris Ostrovsky <boris.ostrovsky@oracle.com>
Signed-off-by: default avatarJuergen Gross <jgross@suse.com>
parent 47cbd598

drivers/net/xen-netfront.c

+12 −41
Original line number Diff line number Diff line
@@ -1921,8 +1921,7 @@ static int setup_netfront(struct xenbus_device *dev, 
			struct netfront_queue *queue, unsigned int feature_split_evtchn)

{

	struct xen_netif_tx_sring *txs;

	struct xen_netif_rx_sring *rxs = NULL;

	grant_ref_t gref;

	struct xen_netif_rx_sring *rxs;

	int err;



	queue->tx_ring_ref = INVALID_GRANT_REF;
@@ -1930,33 +1929,19 @@ static int setup_netfront(struct xenbus_device *dev, 
	queue->rx.sring = NULL;

	queue->tx.sring = NULL;



	txs = (struct xen_netif_tx_sring *)get_zeroed_page(GFP_NOIO | __GFP_HIGH);

	if (!txs) {

		err = -ENOMEM;

		xenbus_dev_fatal(dev, err, "allocating tx ring page");

	err = xenbus_setup_ring(dev, GFP_NOIO | __GFP_HIGH, (void **)&txs,

				1, &queue->tx_ring_ref);

	if (err)

		goto fail;

	}

	SHARED_RING_INIT(txs);

	FRONT_RING_INIT(&queue->tx, txs, XEN_PAGE_SIZE);



	err = xenbus_grant_ring(dev, txs, 1, &gref);

	if (err < 0)

		goto fail;

	queue->tx_ring_ref = gref;

	XEN_FRONT_RING_INIT(&queue->tx, txs, XEN_PAGE_SIZE);



	rxs = (struct xen_netif_rx_sring *)get_zeroed_page(GFP_NOIO | __GFP_HIGH);

	if (!rxs) {

		err = -ENOMEM;

		xenbus_dev_fatal(dev, err, "allocating rx ring page");

	err = xenbus_setup_ring(dev, GFP_NOIO | __GFP_HIGH, (void **)&rxs,

				1, &queue->rx_ring_ref);

	if (err)

		goto fail;

	}

	SHARED_RING_INIT(rxs);

	FRONT_RING_INIT(&queue->rx, rxs, XEN_PAGE_SIZE);



	err = xenbus_grant_ring(dev, rxs, 1, &gref);

	if (err < 0)

		goto fail;

	queue->rx_ring_ref = gref;

	XEN_FRONT_RING_INIT(&queue->rx, rxs, XEN_PAGE_SIZE);



	if (feature_split_evtchn)

		err = setup_netfront_split(queue);
@@ -1972,24 +1957,10 @@ static int setup_netfront(struct xenbus_device *dev, 


	return 0;



	/* If we fail to setup netfront, it is safe to just revoke access to

	 * granted pages because backend is not accessing it at this point.

	 */

 fail:

	if (queue->rx_ring_ref != INVALID_GRANT_REF) {

		gnttab_end_foreign_access(queue->rx_ring_ref,

					  (unsigned long)rxs);

		queue->rx_ring_ref = INVALID_GRANT_REF;

	} else {

		free_page((unsigned long)rxs);

	}

	if (queue->tx_ring_ref != INVALID_GRANT_REF) {

		gnttab_end_foreign_access(queue->tx_ring_ref,

					  (unsigned long)txs);

		queue->tx_ring_ref = INVALID_GRANT_REF;

	} else {

		free_page((unsigned long)txs);

	}

	xenbus_teardown_ring((void **)&queue->rx.sring, 1, &queue->rx_ring_ref);

	xenbus_teardown_ring((void **)&queue->tx.sring, 1, &queue->tx_ring_ref);



	return err;

}