virtio_pci: add isr field

Use isr field instead of direct access to ioaddr.
This way generalizes easily to virtio 1.0.

Signed-off-by: Michael S. Tsirkin <mst@redhat.com>

1 files changed, 6 insertions, 1 deletions

diff --git a/drivers/virtio/virtio_pci.c b/drivers/virtio/virtio_pci.c
index 9be59d9f2f19..ee1b54c93913 100644
--- a/drivers/virtio/virtio_pci.c
+++ b/drivers/virtio/virtio_pci.c
@@ -40,6 +40,9 @@ struct virtio_pci_device
         /* the IO mapping for the PCI config space */
         void __iomem *ioaddr;
 
+        /* the IO mapping for ISR operation */
+        void __iomem *isr;
+
         /* a list of queues so we can dispatch IRQs */
         spinlock_t lock;
         struct list_head virtqueues;
@@ -248,7 +251,7 @@ static irqreturn_t vp_interrupt(int irq, void *opaque)
 
         /* reading the ISR has the effect of also clearing it so it's very
          * important to save off the value. */
-        isr = ioread8(vp_dev->ioaddr + VIRTIO_PCI_ISR);
+        isr = ioread8(vp_dev->isr);
 
         /* It's definitely not us if the ISR was not high */
         if (!isr)
@@ -719,6 +722,8 @@ static int virtio_pci_probe(struct pci_dev *pci_dev,
                 goto out_req_regions;
         }
 
+        vp_dev->isr = vp_dev->ioaddr + VIRTIO_PCI_ISR;
+
         pci_set_drvdata(pci_dev, vp_dev);
         pci_set_master(pci_dev);