Use atomic notifier chain for interrupt handling

modules/mqnic/mqnic.h

@@ -104,6 +104,7 @@ struct mqnic_dev {
 
 	int irq_count;
 	int irq_map[32];
+	struct atomic_notifier_head irq_nh[MQNIC_MAX_IRQ];
 
 	unsigned int id;
 	struct list_head dev_list_node;
@@ -255,7 +256,7 @@ struct mqnic_eq_ring {
 	int int_index;
 	int active;
 
-	int irq;
+	struct notifier_block irq_nb;
 
 	void (*handler)(struct mqnic_eq_ring *ring);
 

modules/mqnic/mqnic_eq.c

@@ -35,6 +35,16 @@
 
 #include "mqnic.h"
 
+static int mqnic_eq_int(struct notifier_block *nb, unsigned long action, void *data)
+{
+	struct mqnic_eq_ring *ring = container_of(nb, struct mqnic_eq_ring, irq_nb);
+
+	mqnic_process_eq(ring);
+	mqnic_arm_eq(ring);
+
+	return NOTIFY_DONE;
+}
+
 int mqnic_create_eq_ring(struct mqnic_priv *priv, struct mqnic_eq_ring **ring_ptr,
 		int size, int stride, int index, u8 __iomem *hw_addr)
 {
@@ -52,6 +62,8 @@ int mqnic_create_eq_ring(struct mqnic_priv *priv, struct mqnic_eq_ring **ring_pt
 	ring->ring_index = index;
 	ring->active = 0;
 
+	ring->irq_nb.notifier_call = mqnic_eq_int;
+
 	ring->size = roundup_pow_of_two(size);
 	ring->size_mask = ring->size - 1;
 	ring->stride = roundup_pow_of_two(stride);
@@ -111,10 +123,20 @@ void mqnic_destroy_eq_ring(struct mqnic_eq_ring **ring_ptr)
 
 int mqnic_activate_eq_ring(struct mqnic_eq_ring *ring, int int_index)
 {
+	int ret = 0;
+
 	if (ring->active)
 		mqnic_deactivate_eq_ring(ring);
 
+	if (int_index < 0 || int_index >= ring->priv->mdev->irq_count)
+		return -EINVAL;
+
+	// register interrupt
 	ring->int_index = int_index;
+	ret = atomic_notifier_chain_register(&ring->priv->mdev->irq_nh[int_index], &ring->irq_nb);
+
+	if (ret)
+		return ret;
 
 	// deactivate queue
 	iowrite32(0, ring->hw_addr + MQNIC_EVENT_QUEUE_ACTIVE_LOG_SIZE_REG);
@@ -134,16 +156,22 @@ int mqnic_activate_eq_ring(struct mqnic_eq_ring *ring, int int_index)
 
 	ring->active = 1;
 
-	return 0;
+	return ret;
 }
 
 void mqnic_deactivate_eq_ring(struct mqnic_eq_ring *ring)
 {
+	int ret = 0;
+
 	// deactivate queue
 	iowrite32(ilog2(ring->size), ring->hw_addr + MQNIC_EVENT_QUEUE_ACTIVE_LOG_SIZE_REG);
 	// disarm queue
 	iowrite32(ring->int_index, ring->hw_addr + MQNIC_EVENT_QUEUE_INTERRUPT_INDEX_REG);
 
+	// unregister interrupt
+	if (ring->active)
+		ret = atomic_notifier_chain_unregister(&ring->priv->mdev->irq_nh[ring->int_index], &ring->irq_nb);
+
 	ring->active = 0;
 }
 

modules/mqnic/mqnic_hw.h

@@ -38,6 +38,8 @@
 
 #include <linux/types.h>
 
+#define MQNIC_MAX_IRQ 32
+
 #define MQNIC_MAX_IF 8
 #define MQNIC_MAX_PORTS 8
 #define MQNIC_MAX_SCHED 8

modules/mqnic/mqnic_main.c

@@ -80,30 +80,9 @@ static unsigned int mqnic_get_free_id(void)
 
 static irqreturn_t mqnic_interrupt(int irq, void *data)
 {
-	struct mqnic_dev *mqnic = data;
-	struct mqnic_priv *priv;
+	struct atomic_notifier_head *nh = data;
 
-	int k, l;
-
-	for (k = 0; k < ARRAY_SIZE(mqnic->ndev); k++) {
-		if (unlikely(!mqnic->ndev[k]))
-			continue;
-
-		priv = netdev_priv(mqnic->ndev[k]);
-
-		if (unlikely(!priv->port_up))
-			continue;
-
-		for (l = 0; l < priv->event_queue_count; l++) {
-			if (unlikely(!priv->event_ring[l]))
-				continue;
-
-			if (priv->event_ring[l]->irq == irq) {
-				mqnic_process_eq(priv->event_ring[l]);
-				mqnic_arm_eq(priv->event_ring[l]);
-			}
-		}
-	}
+	atomic_notifier_call_chain(nh, 0, NULL);
 
 	return IRQ_HANDLED;
 }
@@ -291,9 +270,13 @@ static int mqnic_pci_probe(struct pci_dev *pdev, const struct pci_device_id *ent
 	}
 
 	// Set up interrupts
+	for (k = 0; k < MQNIC_MAX_IRQ; k++) {
+		ATOMIC_INIT_NOTIFIER_HEAD(&mqnic->irq_nh[k]);
+	}
+
 	for (k = 0; k < mqnic->irq_count; k++) {
 		ret = pci_request_irq(pdev, k, mqnic_interrupt, NULL,
-				mqnic, "%s-%d", mqnic->name, k);
+				&mqnic->irq_nh[k], "%s-%d", mqnic->name, k);
 		if (ret < 0) {
 			dev_err(dev, "Failed to request IRQ");
 			goto fail_irq;
@@ -366,7 +349,7 @@ fail_init_netdev:
 fail_board:
 	mqnic_board_deinit(mqnic);
 	for (k = 0; k < mqnic->irq_count; k++)
-		pci_free_irq(pdev, k, mqnic);
+		pci_free_irq(pdev, k, &mqnic->irq_nh[k]);
 fail_irq:
 	pci_free_irq_vectors(pdev);
 fail_map_bars:
@@ -409,7 +392,7 @@ static void mqnic_pci_remove(struct pci_dev *pdev)
 	pci_clear_master(pdev);
 	mqnic_board_deinit(mqnic);
 	for (k = 0; k < mqnic->irq_count; k++)
-		pci_free_irq(pdev, k, mqnic);
+		pci_free_irq(pdev, k, &mqnic->irq_nh[k]);
 	pci_free_irq_vectors(pdev);
 	if (mqnic->hw_addr)
 		pci_iounmap(pdev, mqnic->hw_addr);

modules/mqnic/mqnic_netdev.c

@@ -45,7 +45,6 @@ static int mqnic_start_port(struct net_device *ndev)
 
 	// set up event queues
 	for (k = 0; k < priv->event_queue_count; k++) {
-		priv->event_ring[k]->irq = mdev->irq_map[k % mdev->irq_count];
 		mqnic_activate_eq_ring(priv->event_ring[k], k % mdev->irq_count);
 		mqnic_arm_eq(priv->event_ring[k]);
 	}