enic: do tx cleanup in napi poll

Till now enic had been doing tx clean in isr.

Using napi infrastructure to move the tx clean up out of isr to softirq.
Now, wq isr schedules napi poll. In enic_poll_msix_wq we clean up the tx queus.

This is applicable only on MSIX. In INTx and MSI we use single napi to clean
both rx & tx queues.

Signed-off-by: Govindarajulu Varadarajan <_govind@gmx.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

drivers/net/ethernet/cisco/enic/enic.h

@@ -178,7 +178,7 @@ struct enic {
 	unsigned int rq_count;
 	u64 rq_truncated_pkts;
 	u64 rq_bad_fcs;
-	struct napi_struct napi[ENIC_RQ_MAX];
+	struct napi_struct napi[ENIC_RQ_MAX + ENIC_WQ_MAX];
 
 	/* interrupt resource cache line section */
 	____cacheline_aligned struct vnic_intr intr[ENIC_INTR_MAX];

drivers/net/ethernet/cisco/enic/enic_main.c

@@ -316,40 +316,15 @@ static irqreturn_t enic_isr_msi(int irq, void *data)
 	return IRQ_HANDLED;
 }
 
-static irqreturn_t enic_isr_msix_rq(int irq, void *data)
+static irqreturn_t enic_isr_msix(int irq, void *data)
 {
 	struct napi_struct *napi = data;
 
-	/* schedule NAPI polling for RQ cleanup */
 	napi_schedule(napi);
 
 	return IRQ_HANDLED;
 }
 
-static irqreturn_t enic_isr_msix_wq(int irq, void *data)
-{
-	struct enic *enic = data;
-	unsigned int cq;
-	unsigned int intr;
-	unsigned int wq_work_to_do = -1; /* no limit */
-	unsigned int wq_work_done;
-	unsigned int wq_irq;
-
-	wq_irq = (u32)irq - enic->msix_entry[enic_msix_wq_intr(enic, 0)].vector;
-	cq = enic_cq_wq(enic, wq_irq);
-	intr = enic_msix_wq_intr(enic, wq_irq);
-
-	wq_work_done = vnic_cq_service(&enic->cq[cq],
-		wq_work_to_do, enic_wq_service, NULL);
-
-	vnic_intr_return_credits(&enic->intr[intr],
-		wq_work_done,
-		1 /* unmask intr */,
-		1 /* reset intr timer */);
-
-	return IRQ_HANDLED;
-}
-
 static irqreturn_t enic_isr_msix_err(int irq, void *data)
 {
 	struct enic *enic = data;
@@ -1274,7 +1249,36 @@ int enic_busy_poll(struct napi_struct *napi)
 }
 #endif /* CONFIG_NET_RX_BUSY_POLL */
 
-static int enic_poll_msix(struct napi_struct *napi, int budget)
+static int enic_poll_msix_wq(struct napi_struct *napi, int budget)
+{
+	struct net_device *netdev = napi->dev;
+	struct enic *enic = netdev_priv(netdev);
+	unsigned int wq_index = (napi - &enic->napi[0]) - enic->rq_count;
+	struct vnic_wq *wq = &enic->wq[wq_index];
+	unsigned int cq;
+	unsigned int intr;
+	unsigned int wq_work_to_do = -1; /* clean all desc possible */
+	unsigned int wq_work_done;
+	unsigned int wq_irq;
+
+	wq_irq = wq->index;
+	cq = enic_cq_wq(enic, wq_irq);
+	intr = enic_msix_wq_intr(enic, wq_irq);
+	wq_work_done = vnic_cq_service(&enic->cq[cq], wq_work_to_do,
+				       enic_wq_service, NULL);
+
+	vnic_intr_return_credits(&enic->intr[intr], wq_work_done,
+				 0 /* don't unmask intr */,
+				 1 /* reset intr timer */);
+	if (!wq_work_done) {
+		napi_complete(napi);
+		vnic_intr_unmask(&enic->intr[intr]);
+	}
+
+	return 0;
+}
+
+static int enic_poll_msix_rq(struct napi_struct *napi, int budget)
 {
 	struct net_device *netdev = napi->dev;
 	struct enic *enic = netdev_priv(netdev);
@@ -1399,17 +1403,19 @@ static int enic_request_intr(struct enic *enic)
 			snprintf(enic->msix[intr].devname,
 				sizeof(enic->msix[intr].devname),
 				"%.11s-rx-%d", netdev->name, i);
-			enic->msix[intr].isr = enic_isr_msix_rq;
+			enic->msix[intr].isr = enic_isr_msix;
 			enic->msix[intr].devid = &enic->napi[i];
 		}
 
 		for (i = 0; i < enic->wq_count; i++) {
+			int wq = enic_cq_wq(enic, i);
+
 			intr = enic_msix_wq_intr(enic, i);
 			snprintf(enic->msix[intr].devname,
 				sizeof(enic->msix[intr].devname),
 				"%.11s-tx-%d", netdev->name, i);
-			enic->msix[intr].isr = enic_isr_msix_wq;
-			enic->msix[intr].devid = enic;
+			enic->msix[intr].isr = enic_isr_msix;
+			enic->msix[intr].devid = &enic->napi[wq];
 		}
 
 		intr = enic_msix_err_intr(enic);
@@ -1585,7 +1591,9 @@ static int enic_open(struct net_device *netdev)
 		enic_busy_poll_init_lock(&enic->rq[i]);
 		napi_enable(&enic->napi[i]);
 	}
-
+	if (vnic_dev_get_intr_mode(enic->vdev) == VNIC_DEV_INTR_MODE_MSIX)
+		for (i = 0; i < enic->wq_count; i++)
+			napi_enable(&enic->napi[enic_cq_wq(enic, i)]);
 	enic_dev_enable(enic);
 
 	for (i = 0; i < enic->intr_count; i++)
@@ -1633,6 +1641,9 @@ static int enic_stop(struct net_device *netdev)
 
 	netif_carrier_off(netdev);
 	netif_tx_disable(netdev);
+	if (vnic_dev_get_intr_mode(enic->vdev) == VNIC_DEV_INTR_MODE_MSIX)
+		for (i = 0; i < enic->wq_count; i++)
+			napi_disable(&enic->napi[enic_cq_wq(enic, i)]);
 
 	if (!enic_is_dynamic(enic) && !enic_is_sriov_vf(enic))
 		enic_dev_del_station_addr(enic);
@@ -1752,13 +1763,14 @@ static void enic_poll_controller(struct net_device *netdev)
 	case VNIC_DEV_INTR_MODE_MSIX:
 		for (i = 0; i < enic->rq_count; i++) {
 			intr = enic_msix_rq_intr(enic, i);
-			enic_isr_msix_rq(enic->msix_entry[intr].vector,
-				&enic->napi[i]);
+			enic_isr_msix(enic->msix_entry[intr].vector,
+				      &enic->napi[i]);
 		}
 
 		for (i = 0; i < enic->wq_count; i++) {
 			intr = enic_msix_wq_intr(enic, i);
-			enic_isr_msix_wq(enic->msix_entry[intr].vector, enic);
+			enic_isr_msix(enic->msix_entry[intr].vector,
+				      &enic->napi[enic_cq_wq(enic, i)]);
 		}
 
 		break;
@@ -2159,6 +2171,9 @@ static void enic_dev_deinit(struct enic *enic)
 		napi_hash_del(&enic->napi[i]);
 		netif_napi_del(&enic->napi[i]);
 	}
+	if (vnic_dev_get_intr_mode(enic->vdev) == VNIC_DEV_INTR_MODE_MSIX)
+		for (i = 0; i < enic->wq_count; i++)
+			netif_napi_del(&enic->napi[enic_cq_wq(enic, i)]);
 
 	enic_free_vnic_resources(enic);
 	enic_clear_intr_mode(enic);
@@ -2229,9 +2244,12 @@ static int enic_dev_init(struct enic *enic)
 	case VNIC_DEV_INTR_MODE_MSIX:
 		for (i = 0; i < enic->rq_count; i++) {
 			netif_napi_add(netdev, &enic->napi[i],
-				enic_poll_msix, 64);
+				enic_poll_msix_rq, NAPI_POLL_WEIGHT);
 			napi_hash_add(&enic->napi[i]);
 		}
+		for (i = 0; i < enic->wq_count; i++)
+			netif_napi_add(netdev, &enic->napi[enic_cq_wq(enic, i)],
+				       enic_poll_msix_wq, NAPI_POLL_WEIGHT);
 		break;
 	}