From 2ac061ce97f413bfbbdd768f7d2e0fda2e8170df Mon Sep 17 00:00:00 2001 From: Juergen Gross Date: Mon, 21 Oct 2019 07:30:52 +0200 Subject: [PATCH] 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: Juergen Gross Reviewed-by: Paul Durrant Signed-off-by: Jakub Kicinski --- drivers/net/xen-netback/interface.c | 114 +++++++++++++--------------- 1 file changed, 54 insertions(+), 60 deletions(-) diff --git a/drivers/net/xen-netback/interface.c b/drivers/net/xen-netback/interface.c index 103ed00775eb..68dd7bb07ca6 100644 --- a/drivers/net/xen-netback/interface.c +++ b/drivers/net/xen-netback/interface.c @@ -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);