[PATCH v2 05/17] ibmvfc: add Sub-CRQ IRQ enable/disable routine

[Tyrel Datwyler]

Each Sub-CRQ has its own interrupt. A hypercall is required to toggle
the IRQ state. Provide the necessary mechanism via a helper function.

Signed-off-by: Tyrel Datwyler <tyreld at linux.ibm.com>
Reviewed-by: Brian King <brking at linux.vnet.ibm.com>
---
 drivers/scsi/ibmvscsi/ibmvfc.c | 20 ++++++++++++++++++++
 1 file changed, 20 insertions(+)

diff --git a/drivers/scsi/ibmvscsi/ibmvfc.c b/drivers/scsi/ibmvscsi/ibmvfc.c
index 4860487c6779..97f00fefa809 100644
--- a/drivers/scsi/ibmvscsi/ibmvfc.c
+++ b/drivers/scsi/ibmvscsi/ibmvfc.c
@@ -3361,6 +3361,26 @@ static void ibmvfc_tasklet(void *data)
 	spin_unlock_irqrestore(vhost->host->host_lock, flags);
 }
 
+static int ibmvfc_toggle_scrq_irq(struct ibmvfc_sub_queue *scrq, int enable)
+{
+	struct device *dev = scrq->vhost->dev;
+	struct vio_dev *vdev = to_vio_dev(dev);
+	unsigned long rc;
+	int irq_action = H_ENABLE_VIO_INTERRUPT;
+
+	if (!enable)
+		irq_action = H_DISABLE_VIO_INTERRUPT;
+
+	rc = plpar_hcall_norets(H_VIOCTL, vdev->unit_address, irq_action,
+				scrq->hw_irq, 0, 0);
+
+	if (rc)
+		dev_err(dev, "Couldn't %s sub-crq[%lu] irq. rc=%ld\n",
+			enable ? "enable" : "disable", scrq->hwq_id, rc);
+
+	return rc;
+}
+
 /**
  * ibmvfc_init_tgt - Set the next init job step for the target
  * @tgt:		ibmvfc target struct
-- 
2.27.0