[PATCH net] ibmvnic: Handle processing of CRQ messages in a tasklet

[Thomas Falcon <tlfalcon@linux.vnet.ibm.com>]

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 <tlfalcon@linux.vnet.ibm.com>
---
 drivers/net/ethernet/ibm/ibmvnic.c | 18 +++++++++++++++++-
 drivers/net/ethernet/ibm/ibmvnic.h |  1 +
 2 files changed, 18 insertions(+), 1 deletion(-)

diff --git a/drivers/net/ethernet/ibm/ibmvnic.c b/drivers/net/ethernet/ibm/ibmvnic.c
index 5b66b4f..244be77 100644
--- a/drivers/net/ethernet/ibm/ibmvnic.c
+++ b/drivers/net/ethernet/ibm/ibmvnic.c
@@ -3415,6 +3415,18 @@ static void ibmvnic_handle_crq(union ibmvnic_crq *crq,
 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;
@@ -3440,7 +3452,6 @@ static irqreturn_t ibmvnic_interrupt(int irq, void *instance)
 		}
 	}
 	spin_unlock_irqrestore(&queue->lock, flags);
-	return IRQ_HANDLED;
 }
 
 static int ibmvnic_reenable_crq_queue(struct ibmvnic_adapter *adapter)
@@ -3495,6 +3506,7 @@ static void ibmvnic_release_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));
@@ -3540,6 +3552,9 @@ static int ibmvnic_init_crq_queue(struct ibmvnic_adapter *adapter)
 
 	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);
@@ -3561,6 +3576,7 @@ static int ibmvnic_init_crq_queue(struct ibmvnic_adapter *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));
diff --git a/drivers/net/ethernet/ibm/ibmvnic.h b/drivers/net/ethernet/ibm/ibmvnic.h
index dd775d9..0d0edc3 100644
--- a/drivers/net/ethernet/ibm/ibmvnic.h
+++ b/drivers/net/ethernet/ibm/ibmvnic.h
@@ -1049,5 +1049,6 @@ struct ibmvnic_adapter {
 
 	struct work_struct vnic_crq_init;
 	struct work_struct ibmvnic_xport;
+	struct tasklet_struct tasklet;
 	bool failover;
 };
-- 
2.7.4