ibmvnic: Handle processing of CRQ messages in a tasklet

Create a tasklet to process queued commands or messages received from
firmware instead of processing them in the interrupt handler. Note that
this handler does not process network traffic, but communications related
to resource allocation and device settings.

Signed-off-by: Thomas Falcon <[e-mail]>
Signed-off-by: David S. Miller <[e-mail]>

drivers/net/ethernet/ibm/ibmvnic.c

···
 static irqreturn_t ibmvnic_interrupt(int irq, void *instance)
 {
 	struct ibmvnic_adapter *adapter = instance;
+	unsigned long flags;
+
+	spin_lock_irqsave(&adapter->crq.lock, flags);
+	vio_disable_interrupts(adapter->vdev);
+	tasklet_schedule(&adapter->tasklet);
+	spin_unlock_irqrestore(&adapter->crq.lock, flags);
+	return IRQ_HANDLED;
+}
+
+static void ibmvnic_tasklet(void *data)
+{
+	struct ibmvnic_adapter *adapter = data;
 	struct ibmvnic_crq_queue *queue = &adapter->crq;
 	struct vio_dev *vdev = adapter->vdev;
 	union ibmvnic_crq *crq;
···
 		}
 	}
 	spin_unlock_irqrestore(&queue->lock, flags);
-	return IRQ_HANDLED;
 }
 
 static int ibmvnic_reenable_crq_queue(struct ibmvnic_adapter *adapter)
···
 
 	netdev_dbg(adapter->netdev, "Releasing CRQ\n");
 	free_irq(vdev->irq, adapter);
+	tasklet_kill(&adapter->tasklet);
 	do {
 		rc = plpar_hcall_norets(H_FREE_CRQ, vdev->unit_address);
 	} while (rc == H_BUSY || H_IS_LONG_BUSY(rc));
···
 
 	retrc = 0;
 
+	tasklet_init(&adapter->tasklet, (void *)ibmvnic_tasklet,
+		     (unsigned long)adapter);
+
 	netdev_dbg(adapter->netdev, "registering irq 0x%x\n", vdev->irq);
 	rc = request_irq(vdev->irq, ibmvnic_interrupt, 0, IBMVNIC_NAME,
 			 adapter);
···
 	return retrc;
 
 req_irq_failed:
+	tasklet_kill(&adapter->tasklet);
 	do {
 		rc = plpar_hcall_norets(H_FREE_CRQ, vdev->unit_address);
 	} while (rc == H_BUSY || H_IS_LONG_BUSY(rc));

drivers/net/ethernet/ibm/ibmvnic.h

···
 
 	struct work_struct vnic_crq_init;
 	struct work_struct ibmvnic_xport;
+	struct tasklet_struct tasklet;
 	bool failover;
 };