diff --git a/drivers/net/xen-netback/common.h b/drivers/net/xen-netback/common.h index ae477f7756af..8ee24e351bdc 100644 --- a/drivers/net/xen-netback/common.h +++ b/drivers/net/xen-netback/common.h @@ -140,6 +140,20 @@ struct xenvif_queue { /* Per-queue data for xenvif */ char name[QUEUE_NAME_SIZE]; /* DEVNAME-qN */ struct xenvif *vif; /* Parent VIF */ + /* + * TX/RX common EOI handling. + * When feature-split-event-channels = 0, interrupt handler sets + * NETBK_COMMON_EOI, otherwise NETBK_RX_EOI and NETBK_TX_EOI are set + * by the RX and TX interrupt handlers. + * RX and TX handler threads will issue an EOI when either + * NETBK_COMMON_EOI or their specific bits (NETBK_RX_EOI or + * NETBK_TX_EOI) are set and they will reset those bits. + */ + atomic_t eoi_pending; +#define NETBK_RX_EOI 0x01 +#define NETBK_TX_EOI 0x02 +#define NETBK_COMMON_EOI 0x04 + /* Use NAPI for guest TX */ struct napi_struct napi; /* When feature-split-event-channels = 0, tx_irq = rx_irq. */ @@ -378,6 +392,7 @@ int xenvif_dealloc_kthread(void *data); irqreturn_t xenvif_ctrl_irq_fn(int irq, void *data); +bool xenvif_have_rx_work(struct xenvif_queue *queue, bool test_kthread); void xenvif_rx_action(struct xenvif_queue *queue); void xenvif_rx_queue_tail(struct xenvif_queue *queue, struct sk_buff *skb); diff --git a/drivers/net/xen-netback/interface.c b/drivers/net/xen-netback/interface.c index 8af497285691..acb786d8b1d8 100644 --- a/drivers/net/xen-netback/interface.c +++ b/drivers/net/xen-netback/interface.c @@ -77,12 +77,28 @@ int xenvif_schedulable(struct xenvif *vif) !vif->disabled; } +static bool xenvif_handle_tx_interrupt(struct xenvif_queue *queue) +{ + bool rc; + + rc = RING_HAS_UNCONSUMED_REQUESTS(&queue->tx); + if (rc) + napi_schedule(&queue->napi); + return rc; +} + static irqreturn_t xenvif_tx_interrupt(int irq, void *dev_id) { struct xenvif_queue *queue = dev_id; + int old; - if (RING_HAS_UNCONSUMED_REQUESTS(&queue->tx)) - napi_schedule(&queue->napi); + old = atomic_fetch_or(NETBK_TX_EOI, &queue->eoi_pending); + WARN(old & NETBK_TX_EOI, "Interrupt while EOI pending\n"); + + if (!xenvif_handle_tx_interrupt(queue)) { + atomic_andnot(NETBK_TX_EOI, &queue->eoi_pending); + xen_irq_lateeoi(irq, XEN_EOI_FLAG_SPURIOUS); + } return IRQ_HANDLED; } @@ -116,19 +132,46 @@ static int xenvif_poll(struct napi_struct *napi, int budget) return work_done; } +static bool xenvif_handle_rx_interrupt(struct xenvif_queue *queue) +{ + bool rc; + + rc = xenvif_have_rx_work(queue, false); + if (rc) + xenvif_kick_thread(queue); + return rc; +} + static irqreturn_t xenvif_rx_interrupt(int irq, void *dev_id) { struct xenvif_queue *queue = dev_id; + int old; - xenvif_kick_thread(queue); + old = atomic_fetch_or(NETBK_RX_EOI, &queue->eoi_pending); + WARN(old & NETBK_RX_EOI, "Interrupt while EOI pending\n"); + + if (!xenvif_handle_rx_interrupt(queue)) { + atomic_andnot(NETBK_RX_EOI, &queue->eoi_pending); + xen_irq_lateeoi(irq, XEN_EOI_FLAG_SPURIOUS); + } return IRQ_HANDLED; } irqreturn_t xenvif_interrupt(int irq, void *dev_id) { - xenvif_tx_interrupt(irq, dev_id); - xenvif_rx_interrupt(irq, dev_id); + struct xenvif_queue *queue = dev_id; + int old; + + old = atomic_fetch_or(NETBK_COMMON_EOI, &queue->eoi_pending); + WARN(old, "Interrupt while EOI pending\n"); + + /* Use bitwise or as we need to call both functions. */ + if ((!xenvif_handle_tx_interrupt(queue) | + !xenvif_handle_rx_interrupt(queue))) { + atomic_andnot(NETBK_COMMON_EOI, &queue->eoi_pending); + xen_irq_lateeoi(irq, XEN_EOI_FLAG_SPURIOUS); + } return IRQ_HANDLED; } @@ -605,7 +648,7 @@ int xenvif_connect_ctrl(struct xenvif *vif, grant_ref_t ring_ref, if (req_prod - rsp_prod > RING_SIZE(&vif->ctrl)) goto err_unmap; - err = bind_interdomain_evtchn_to_irq(vif->domid, evtchn); + err = bind_interdomain_evtchn_to_irq_lateeoi(vif->domid, evtchn); if (err < 0) goto err_unmap; @@ -709,7 +752,7 @@ int xenvif_connect_data(struct xenvif_queue *queue, if (tx_evtchn == rx_evtchn) { /* feature-split-event-channels == 0 */ - err = bind_interdomain_evtchn_to_irqhandler( + err = bind_interdomain_evtchn_to_irqhandler_lateeoi( queue->vif->domid, tx_evtchn, xenvif_interrupt, 0, queue->name, queue); if (err < 0) @@ -720,7 +763,7 @@ int xenvif_connect_data(struct xenvif_queue *queue, /* feature-split-event-channels == 1 */ snprintf(queue->tx_irq_name, sizeof(queue->tx_irq_name), "%s-tx", queue->name); - err = bind_interdomain_evtchn_to_irqhandler( + err = bind_interdomain_evtchn_to_irqhandler_lateeoi( queue->vif->domid, tx_evtchn, xenvif_tx_interrupt, 0, queue->tx_irq_name, queue); if (err < 0) @@ -730,7 +773,7 @@ int xenvif_connect_data(struct xenvif_queue *queue, snprintf(queue->rx_irq_name, sizeof(queue->rx_irq_name), "%s-rx", queue->name); - err = bind_interdomain_evtchn_to_irqhandler( + err = bind_interdomain_evtchn_to_irqhandler_lateeoi( queue->vif->domid, rx_evtchn, xenvif_rx_interrupt, 0, queue->rx_irq_name, queue); if (err < 0) diff --git a/drivers/net/xen-netback/netback.c b/drivers/net/xen-netback/netback.c index 6dfca7265644..bc3421d14576 100644 --- a/drivers/net/xen-netback/netback.c +++ b/drivers/net/xen-netback/netback.c @@ -169,6 +169,10 @@ void xenvif_napi_schedule_or_enable_events(struct xenvif_queue *queue) if (more_to_do) napi_schedule(&queue->napi); + else if (atomic_fetch_andnot(NETBK_TX_EOI | NETBK_COMMON_EOI, + &queue->eoi_pending) & + (NETBK_TX_EOI | NETBK_COMMON_EOI)) + xen_irq_lateeoi(queue->tx_irq, 0); } static void tx_add_credit(struct xenvif_queue *queue) @@ -1643,9 +1647,14 @@ static bool xenvif_ctrl_work_todo(struct xenvif *vif) irqreturn_t xenvif_ctrl_irq_fn(int irq, void *data) { struct xenvif *vif = data; + unsigned int eoi_flag = XEN_EOI_FLAG_SPURIOUS; - while (xenvif_ctrl_work_todo(vif)) + while (xenvif_ctrl_work_todo(vif)) { xenvif_ctrl_action(vif); + eoi_flag = 0; + } + + xen_irq_lateeoi(irq, eoi_flag); return IRQ_HANDLED; } diff --git a/drivers/net/xen-netback/rx.c b/drivers/net/xen-netback/rx.c index ac034f69a170..b8febe1d1bfd 100644 --- a/drivers/net/xen-netback/rx.c +++ b/drivers/net/xen-netback/rx.c @@ -503,13 +503,13 @@ static bool xenvif_rx_queue_ready(struct xenvif_queue *queue) return queue->stalled && prod - cons >= 1; } -static bool xenvif_have_rx_work(struct xenvif_queue *queue) +bool xenvif_have_rx_work(struct xenvif_queue *queue, bool test_kthread) { return xenvif_rx_ring_slots_available(queue) || (queue->vif->stall_timeout && (xenvif_rx_queue_stalled(queue) || xenvif_rx_queue_ready(queue))) || - kthread_should_stop() || + (test_kthread && kthread_should_stop()) || queue->vif->disabled; } @@ -540,15 +540,20 @@ static void xenvif_wait_for_rx_work(struct xenvif_queue *queue) { DEFINE_WAIT(wait); - if (xenvif_have_rx_work(queue)) + if (xenvif_have_rx_work(queue, true)) return; for (;;) { long ret; prepare_to_wait(&queue->wq, &wait, TASK_INTERRUPTIBLE); - if (xenvif_have_rx_work(queue)) + if (xenvif_have_rx_work(queue, true)) break; + if (atomic_fetch_andnot(NETBK_RX_EOI | NETBK_COMMON_EOI, + &queue->eoi_pending) & + (NETBK_RX_EOI | NETBK_COMMON_EOI)) + xen_irq_lateeoi(queue->rx_irq, 0); + ret = schedule_timeout(xenvif_rx_queue_timeout(queue)); if (!ret) break;