Commit 2ac061ce authored by Juergen Gross's avatar Juergen Gross Committed by Jakub Kicinski
Browse files

xen/netback: cleanup init and deinit code 



Do some cleanup of the netback init and deinit code:

- add an omnipotent queue deinit function usable from
  xenvif_disconnect_data() and the error path of xenvif_connect_data()
- only install the irq handlers after initializing all relevant items
  (especially the kthreads related to the queue)
- there is no need to use get_task_struct() after creating a kthread
  and using put_task_struct() again after having stopped it.
- use kthread_run() instead of kthread_create() to spare the call of
  wake_up_process().

Signed-off-by: default avatarJuergen Gross <jgross@suse.com>
Reviewed-by: default avatarPaul Durrant <pdurrant@gmail.com>
Signed-off-by: default avatarJakub Kicinski <jakub.kicinski@netronome.com>
parent 88238d2d

drivers/net/xen-netback/interface.c

+54 −60
Original line number Diff line number Diff line
@@ -626,6 +626,38 @@ err: 
	return err;

}



static void xenvif_disconnect_queue(struct xenvif_queue *queue)

{

	if (queue->tx_irq) {

		unbind_from_irqhandler(queue->tx_irq, queue);

		if (queue->tx_irq == queue->rx_irq)

			queue->rx_irq = 0;

		queue->tx_irq = 0;

	}



	if (queue->rx_irq) {

		unbind_from_irqhandler(queue->rx_irq, queue);

		queue->rx_irq = 0;

	}



	if (queue->task) {

		kthread_stop(queue->task);

		queue->task = NULL;

	}



	if (queue->dealloc_task) {

		kthread_stop(queue->dealloc_task);

		queue->dealloc_task = NULL;

	}



	if (queue->napi.poll) {

		netif_napi_del(&queue->napi);

		queue->napi.poll = NULL;

	}



	xenvif_unmap_frontend_data_rings(queue);

}



int xenvif_connect_data(struct xenvif_queue *queue,

			unsigned long tx_ring_ref,

			unsigned long rx_ring_ref,
@@ -651,13 +683,27 @@ int xenvif_connect_data(struct xenvif_queue *queue, 
	netif_napi_add(queue->vif->dev, &queue->napi, xenvif_poll,

			XENVIF_NAPI_WEIGHT);



	queue->stalled = true;



	task = kthread_run(xenvif_kthread_guest_rx, queue,

			   "%s-guest-rx", queue->name);

	if (IS_ERR(task))

		goto kthread_err;

	queue->task = task;



	task = kthread_run(xenvif_dealloc_kthread, queue,

			   "%s-dealloc", queue->name);

	if (IS_ERR(task))

		goto kthread_err;

	queue->dealloc_task = task;



	if (tx_evtchn == rx_evtchn) {

		/* feature-split-event-channels == 0 */

		err = bind_interdomain_evtchn_to_irqhandler(

			queue->vif->domid, tx_evtchn, xenvif_interrupt, 0,

			queue->name, queue);

		if (err < 0)

			goto err_unmap;

			goto err;

		queue->tx_irq = queue->rx_irq = err;

		disable_irq(queue->tx_irq);

	} else {
@@ -668,7 +714,7 @@ int xenvif_connect_data(struct xenvif_queue *queue, 
			queue->vif->domid, tx_evtchn, xenvif_tx_interrupt, 0,

			queue->tx_irq_name, queue);

		if (err < 0)

			goto err_unmap;

			goto err;

		queue->tx_irq = err;

		disable_irq(queue->tx_irq);
@@ -678,47 +724,18 @@ int xenvif_connect_data(struct xenvif_queue *queue, 
			queue->vif->domid, rx_evtchn, xenvif_rx_interrupt, 0,

			queue->rx_irq_name, queue);

		if (err < 0)

			goto err_tx_unbind;

			goto err;

		queue->rx_irq = err;

		disable_irq(queue->rx_irq);

	}



	queue->stalled = true;



	task = kthread_create(xenvif_kthread_guest_rx,

			      (void *)queue, "%s-guest-rx", queue->name);

	if (IS_ERR(task)) {

		pr_warn("Could not allocate kthread for %s\n", queue->name);

		err = PTR_ERR(task);

		goto err_rx_unbind;

	}

	queue->task = task;

	get_task_struct(task);

	return 0;



	task = kthread_create(xenvif_dealloc_kthread,

			      (void *)queue, "%s-dealloc", queue->name);

	if (IS_ERR(task)) {

kthread_err:

	pr_warn("Could not allocate kthread for %s\n", queue->name);

	err = PTR_ERR(task);

		goto err_rx_unbind;

	}

	queue->dealloc_task = task;



	wake_up_process(queue->task);

	wake_up_process(queue->dealloc_task);



	return 0;



err_rx_unbind:

	unbind_from_irqhandler(queue->rx_irq, queue);

	queue->rx_irq = 0;

err_tx_unbind:

	unbind_from_irqhandler(queue->tx_irq, queue);

	queue->tx_irq = 0;

err_unmap:

	xenvif_unmap_frontend_data_rings(queue);

	netif_napi_del(&queue->napi);

err:

	xenvif_disconnect_queue(queue);

	return err;

}
@@ -746,30 +763,7 @@ void xenvif_disconnect_data(struct xenvif *vif) 
	for (queue_index = 0; queue_index < num_queues; ++queue_index) {

		queue = &vif->queues[queue_index];



		netif_napi_del(&queue->napi);



		if (queue->task) {

			kthread_stop(queue->task);

			put_task_struct(queue->task);

			queue->task = NULL;

		}



		if (queue->dealloc_task) {

			kthread_stop(queue->dealloc_task);

			queue->dealloc_task = NULL;

		}



		if (queue->tx_irq) {

			if (queue->tx_irq == queue->rx_irq)

				unbind_from_irqhandler(queue->tx_irq, queue);

			else {

				unbind_from_irqhandler(queue->tx_irq, queue);

				unbind_from_irqhandler(queue->rx_irq, queue);

			}

			queue->tx_irq = 0;

		}



		xenvif_unmap_frontend_data_rings(queue);

		xenvif_disconnect_queue(queue);

	}



	xenvif_mcast_addr_list_free(vif);

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