[PATCH net-next v2 6/8] net: thunderx: Rework interrupt handling

[Aleksey Makarov <aleksey.makarov@auriga.com>]

From: Sunil Goutham <sgoutham@cavium.com>

Rework interrupt handler to avoid checking IRQ affinity of
CQ interrupts. Now separate handlers are registered for each IRQ
including RBDR. Register interrupt handlers for only those
which are being used. Add nicvf_dump_intr_status() and use it
in irq handlers.

Signed-off-by: Sunil Goutham <sgoutham@cavium.com>
Signed-off-by: Aleksey Makarov <aleksey.makarov@caviumnetworks.com>
---
 drivers/net/ethernet/cavium/thunder/nic.h          |   1 +
 drivers/net/ethernet/cavium/thunder/nicvf_main.c   | 172 ++++++++++++---------
 drivers/net/ethernet/cavium/thunder/nicvf_queues.h |   1 +
 3 files changed, 102 insertions(+), 72 deletions(-)

diff --git a/drivers/net/ethernet/cavium/thunder/nic.h b/drivers/net/ethernet/cavium/thunder/nic.h
index a83f567..89b997e 100644
--- a/drivers/net/ethernet/cavium/thunder/nic.h
+++ b/drivers/net/ethernet/cavium/thunder/nic.h
@@ -135,6 +135,7 @@
 #define	NICVF_TX_TIMEOUT		(50 * HZ)
 
 struct nicvf_cq_poll {
+	struct  nicvf *nicvf;
 	u8	cq_idx;		/* Completion queue index */
 	struct	napi_struct napi;
 };
diff --git a/drivers/net/ethernet/cavium/thunder/nicvf_main.c b/drivers/net/ethernet/cavium/thunder/nicvf_main.c
index de51828..85213f3 100644
--- a/drivers/net/ethernet/cavium/thunder/nicvf_main.c
+++ b/drivers/net/ethernet/cavium/thunder/nicvf_main.c
@@ -653,11 +653,20 @@ static void nicvf_handle_qs_err(unsigned long data)
 	nicvf_enable_intr(nic, NICVF_INTR_QS_ERR, 0);
 }
 
+static void nicvf_dump_intr_status(struct nicvf *nic)
+{
+	if (netif_msg_intr(nic))
+		netdev_info(nic->netdev, "%s: interrupt status 0x%llx\n",
+			    nic->netdev->name, nicvf_reg_read(nic, NIC_VF_INT));
+}
+
 static irqreturn_t nicvf_misc_intr_handler(int irq, void *nicvf_irq)
 {
 	struct nicvf *nic = (struct nicvf *)nicvf_irq;
 	u64 intr;
 
+	nicvf_dump_intr_status(nic);
+
 	intr = nicvf_reg_read(nic, NIC_VF_INT);
 	/* Check for spurious interrupt */
 	if (!(intr & NICVF_INTR_MBOX_MASK))
@@ -668,59 +677,58 @@ static irqreturn_t nicvf_misc_intr_handler(int irq, void *nicvf_irq)
 	return IRQ_HANDLED;
 }
 
-static irqreturn_t nicvf_intr_handler(int irq, void *nicvf_irq)
+static irqreturn_t nicvf_intr_handler(int irq, void *cq_irq)
+{
+	struct nicvf_cq_poll *cq_poll = (struct nicvf_cq_poll *)cq_irq;
+	struct nicvf *nic = cq_poll->nicvf;
+	int qidx = cq_poll->cq_idx;
+
+	nicvf_dump_intr_status(nic);
+
+	/* Disable interrupts */
+	nicvf_disable_intr(nic, NICVF_INTR_CQ, qidx);
+
+	/* Schedule NAPI */
+	napi_schedule(&cq_poll->napi);
+
+	/* Clear interrupt */
+	nicvf_clear_intr(nic, NICVF_INTR_CQ, qidx);
+
+	return IRQ_HANDLED;
+}
+
+static irqreturn_t nicvf_rbdr_intr_handler(int irq, void *nicvf_irq)
 {
-	u64 qidx, intr, clear_intr = 0;
-	u64 cq_intr, rbdr_intr, qs_err_intr;
 	struct nicvf *nic = (struct nicvf *)nicvf_irq;
-	struct queue_set *qs = nic->qs;
-	struct nicvf_cq_poll *cq_poll = NULL;
+	u8 qidx;
 
-	intr = nicvf_reg_read(nic, NIC_VF_INT);
-	if (netif_msg_intr(nic))
-		netdev_info(nic->netdev, "%s: interrupt status 0x%llx\n",
-			    nic->netdev->name, intr);
-
-	qs_err_intr = intr & NICVF_INTR_QS_ERR_MASK;
-	if (qs_err_intr) {
-		/* Disable Qset err interrupt and schedule softirq */
-		nicvf_disable_intr(nic, NICVF_INTR_QS_ERR, 0);
-		tasklet_hi_schedule(&nic->qs_err_task);
-		clear_intr |= qs_err_intr;
-	}
 
-	/* Disable interrupts and start polling */
-	cq_intr = (intr & NICVF_INTR_CQ_MASK) >> NICVF_INTR_CQ_SHIFT;
-	for (qidx = 0; qidx < qs->cq_cnt; qidx++) {
-		if (!(cq_intr & (1 << qidx)))
-			continue;
-		if (!nicvf_is_intr_enabled(nic, NICVF_INTR_CQ, qidx))
+	nicvf_dump_intr_status(nic);
+
+	/* Disable RBDR interrupt and schedule softirq */
+	for (qidx = 0; qidx < nic->qs->rbdr_cnt; qidx++) {
+		if (!nicvf_is_intr_enabled(nic, NICVF_INTR_RBDR, qidx))
 			continue;
+		nicvf_disable_intr(nic, NICVF_INTR_RBDR, qidx);
+		tasklet_hi_schedule(&nic->rbdr_task);
+		/* Clear interrupt */
+		nicvf_clear_intr(nic, NICVF_INTR_RBDR, qidx);
+	}
 
-		nicvf_disable_intr(nic, NICVF_INTR_CQ, qidx);
-		clear_intr |= ((1 << qidx) << NICVF_INTR_CQ_SHIFT);
+	return IRQ_HANDLED;
+}
 
-		cq_poll = nic->napi[qidx];
-		/* Schedule NAPI */
-		if (cq_poll)
-			napi_schedule(&cq_poll->napi);
-	}
+static irqreturn_t nicvf_qs_err_intr_handler(int irq, void *nicvf_irq)
+{
+	struct nicvf *nic = (struct nicvf *)nicvf_irq;
 
-	/* Handle RBDR interrupts */
-	rbdr_intr = (intr & NICVF_INTR_RBDR_MASK) >> NICVF_INTR_RBDR_SHIFT;
-	if (rbdr_intr) {
-		/* Disable RBDR interrupt and schedule softirq */
-		for (qidx = 0; qidx < qs->rbdr_cnt; qidx++) {
-			if (!nicvf_is_intr_enabled(nic, NICVF_INTR_RBDR, qidx))
-				continue;
-			nicvf_disable_intr(nic, NICVF_INTR_RBDR, qidx);
-			tasklet_hi_schedule(&nic->rbdr_task);
-			clear_intr |= ((1 << qidx) << NICVF_INTR_RBDR_SHIFT);
-		}
-	}
+	nicvf_dump_intr_status(nic);
+
+	/* Disable Qset err interrupt and schedule softirq */
+	nicvf_disable_intr(nic, NICVF_INTR_QS_ERR, 0);
+	tasklet_hi_schedule(&nic->qs_err_task);
+	nicvf_clear_intr(nic, NICVF_INTR_QS_ERR, 0);
 
-	/* Clear interrupts */
-	nicvf_reg_write(nic, NIC_VF_INT, clear_intr);
 	return IRQ_HANDLED;
 }
 
@@ -754,7 +762,7 @@ static void nicvf_disable_msix(struct nicvf *nic)
 
 static int nicvf_register_interrupts(struct nicvf *nic)
 {
-	int irq, free, ret = 0;
+	int irq, ret = 0;
 	int vector;
 
 	for_each_cq_irq(irq)
@@ -769,44 +777,42 @@ static int nicvf_register_interrupts(struct nicvf *nic)
 		sprintf(nic->irq_name[irq], "NICVF%d RBDR%d",
 			nic->vf_id, irq - NICVF_INTR_ID_RBDR);
 
-	/* Register all interrupts except mailbox */
-	for (irq = 0; irq < NICVF_INTR_ID_SQ; irq++) {
+	/* Register CQ interrupts */
+	for (irq = 0; irq < nic->qs->cq_cnt; irq++) {
 		vector = nic->msix_entries[irq].vector;
 		ret = request_irq(vector, nicvf_intr_handler,
-				  0, nic->irq_name[irq], nic);
+				  0, nic->irq_name[irq], nic->napi[irq]);
 		if (ret)
-			break;
+			goto err;
 		nic->irq_allocated[irq] = true;
 	}
 
-	for (irq = NICVF_INTR_ID_SQ; irq < NICVF_INTR_ID_MISC; irq++) {
+	/* Register RBDR interrupt */
+	for (irq = NICVF_INTR_ID_RBDR;
+	     irq < (NICVF_INTR_ID_RBDR + nic->qs->rbdr_cnt); irq++) {
 		vector = nic->msix_entries[irq].vector;
-		ret = request_irq(vector, nicvf_intr_handler,
+		ret = request_irq(vector, nicvf_rbdr_intr_handler,
 				  0, nic->irq_name[irq], nic);
 		if (ret)
-			break;
+			goto err;
 		nic->irq_allocated[irq] = true;
 	}
 
+	/* Register QS error interrupt */
 	sprintf(nic->irq_name[NICVF_INTR_ID_QS_ERR],
 		"NICVF%d Qset error", nic->vf_id);
-	if (!ret) {
-		vector = nic->msix_entries[NICVF_INTR_ID_QS_ERR].vector;
-		irq = NICVF_INTR_ID_QS_ERR;
-		ret = request_irq(vector, nicvf_intr_handler,
-				  0, nic->irq_name[irq], nic);
-		if (!ret)
-			nic->irq_allocated[irq] = true;
-	}
+	irq = NICVF_INTR_ID_QS_ERR;
+	ret = request_irq(nic->msix_entries[irq].vector,
+			  nicvf_qs_err_intr_handler,
+			  0, nic->irq_name[irq], nic);
+	if (!ret)
+		nic->irq_allocated[irq] = true;
 
-	if (ret) {
-		netdev_err(nic->netdev, "Request irq failed\n");
-		for (free = 0; free < irq; free++)
-			free_irq(nic->msix_entries[free].vector, nic);
-		return ret;
-	}
+err:
+	if (ret)
+		netdev_err(nic->netdev, "request_irq failed, vector %d\n", irq);
 
-	return 0;
+	return ret;
 }
 
 static void nicvf_unregister_interrupts(struct nicvf *nic)
@@ -815,8 +821,14 @@ static void nicvf_unregister_interrupts(struct nicvf *nic)
 
 	/* Free registered interrupts */
 	for (irq = 0; irq < nic->num_vec; irq++) {
-		if (nic->irq_allocated[irq])
+		if (!nic->irq_allocated[irq])
+			continue;
+
+		if (irq < NICVF_INTR_ID_SQ)
+			free_irq(nic->msix_entries[irq].vector, nic->napi[irq]);
+		else
 			free_irq(nic->msix_entries[irq].vector, nic);
+
 		nic->irq_allocated[irq] = false;
 	}
 
@@ -888,6 +900,20 @@ static netdev_tx_t nicvf_xmit(struct sk_buff *skb, struct net_device *netdev)
 	return NETDEV_TX_OK;
 }
 
+static inline void nicvf_free_cq_poll(struct nicvf *nic)
+{
+	struct nicvf_cq_poll *cq_poll;
+	int qidx;
+
+	for (qidx = 0; qidx < nic->qs->cq_cnt; qidx++) {
+		cq_poll = nic->napi[qidx];
+		if (!cq_poll)
+			continue;
+		nic->napi[qidx] = NULL;
+		kfree(cq_poll);
+	}
+}
+
 int nicvf_stop(struct net_device *netdev)
 {
 	int irq, qidx;
@@ -922,7 +948,6 @@ int nicvf_stop(struct net_device *netdev)
 		cq_poll = nic->napi[qidx];
 		if (!cq_poll)
 			continue;
-		nic->napi[qidx] = NULL;
 		napi_synchronize(&cq_poll->napi);
 		/* CQ intr is enabled while napi_complete,
 		 * so disable it now
@@ -931,7 +956,6 @@ int nicvf_stop(struct net_device *netdev)
 		nicvf_clear_intr(nic, NICVF_INTR_CQ, qidx);
 		napi_disable(&cq_poll->napi);
 		netif_napi_del(&cq_poll->napi);
-		kfree(cq_poll);
 	}
 
 	netif_tx_disable(netdev);
@@ -947,6 +971,8 @@ int nicvf_stop(struct net_device *netdev)
 
 	nicvf_unregister_interrupts(nic);
 
+	nicvf_free_cq_poll(nic);
+
 	return 0;
 }
 
@@ -973,6 +999,7 @@ int nicvf_open(struct net_device *netdev)
 			goto napi_del;
 		}
 		cq_poll->cq_idx = qidx;
+		cq_poll->nicvf = nic;
 		netif_napi_add(netdev, &cq_poll->napi, nicvf_poll,
 			       NAPI_POLL_WEIGHT);
 		napi_enable(&cq_poll->napi);
@@ -1040,6 +1067,8 @@ int nicvf_open(struct net_device *netdev)
 cleanup:
 	nicvf_disable_intr(nic, NICVF_INTR_MBOX, 0);
 	nicvf_unregister_interrupts(nic);
+	tasklet_kill(&nic->qs_err_task);
+	tasklet_kill(&nic->rbdr_task);
 napi_del:
 	for (qidx = 0; qidx < qs->cq_cnt; qidx++) {
 		cq_poll = nic->napi[qidx];
@@ -1047,9 +1076,8 @@ napi_del:
 			continue;
 		napi_disable(&cq_poll->napi);
 		netif_napi_del(&cq_poll->napi);
-		kfree(cq_poll);
-		nic->napi[qidx] = NULL;
 	}
+	nicvf_free_cq_poll(nic);
 	return err;
 }
 
diff --git a/drivers/net/ethernet/cavium/thunder/nicvf_queues.h b/drivers/net/ethernet/cavium/thunder/nicvf_queues.h
index 8b93dd6..fb4957d 100644
--- a/drivers/net/ethernet/cavium/thunder/nicvf_queues.h
+++ b/drivers/net/ethernet/cavium/thunder/nicvf_queues.h
@@ -251,6 +251,7 @@ struct cmp_queue {
 	void		*desc;
 	struct q_desc_mem   dmem;
 	struct cmp_queue_stats	stats;
+	int		irq;
 } ____cacheline_aligned_in_smp;
 
 struct snd_queue {
-- 
2.5.0