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xen/netback: cleanup init and deinit code

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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: Juergen Gross <jgross@suse.com>
Reviewed-by: Paul Durrant <pdurrant@gmail.com>
Signed-off-by: Jakub Kicinski <jakub.kicinski@netronome.com>
This commit is contained in:
Juergen Gross 2019-10-21 07:30:52 +02:00 committed by Jakub Kicinski
parent 88238d2d22
commit 2ac061ce97
1 changed files with 54 additions and 60 deletions
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114
drivers/net/xen-netback/interface.c
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@ -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);
task = kthread_create(xenvif_dealloc_kthread,
(void *)queue, "%s-dealloc", 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->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);
kthread_err:
pr_warn("Could not allocate kthread for %s\n", queue->name);
err = PTR_ERR(task);
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);