[SCSI] ibmvfc: Add suspend/resume support

Adds support for resuming from suspend for IBM VFC devices. We may have
lost an interrupt over the suspend, so we just kick the interrupt handler
to process anything that is outstanding. We expect to find a transport event
indicating we need to reestablish our CRQ.

Signed-off-by: Brian King <brking@linux.vnet.ibm.com>
Signed-off-by: James Bottomley <James.Bottomley@suse.de>

drivers/scsi/ibmvscsi/ibmvfc.c

@@ -29,6 +29,7 @@
 #include <linux/interrupt.h>
 #include <linux/kthread.h>
 #include <linux/of.h>
+#include <linux/pm.h>
 #include <linux/stringify.h>
 #include <asm/firmware.h>
 #include <asm/irq.h>
@@ -4735,6 +4736,27 @@ static int ibmvfc_remove(struct vio_dev *vdev)
 	return 0;
 }
 
+/**
+ * ibmvfc_resume - Resume from suspend
+ * @dev:	device struct
+ *
+ * We may have lost an interrupt across suspend/resume, so kick the
+ * interrupt handler
+ *
+ */
+static int ibmvfc_resume(struct device *dev)
+{
+	unsigned long flags;
+	struct ibmvfc_host *vhost = dev_get_drvdata(dev);
+	struct vio_dev *vdev = to_vio_dev(dev);
+
+	spin_lock_irqsave(vhost->host->host_lock, flags);
+	vio_disable_interrupts(vdev);
+	tasklet_schedule(&vhost->tasklet);
+	spin_unlock_irqrestore(vhost->host->host_lock, flags);
+	return 0;
+}
+
 /**
  * ibmvfc_get_desired_dma - Calculate DMA resources needed by the driver
  * @vdev:	vio device struct
@@ -4755,6 +4777,10 @@ static struct vio_device_id ibmvfc_device_table[] __devinitdata = {
 };
 MODULE_DEVICE_TABLE(vio, ibmvfc_device_table);
 
+static struct dev_pm_ops ibmvfc_pm_ops = {
+	.resume = ibmvfc_resume
+};
+
 static struct vio_driver ibmvfc_driver = {
 	.id_table = ibmvfc_device_table,
 	.probe = ibmvfc_probe,
@@ -4763,6 +4789,7 @@ static struct vio_driver ibmvfc_driver = {
 	.driver = {
 		.name = IBMVFC_NAME,
 		.owner = THIS_MODULE,
+		.pm = &ibmvfc_pm_ops,
 	}
 };