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>

diff --git a/drivers/virtio/virtio_pci.c b/drivers/virtio/virtio_pci.c
index 9be59d9..ee1b54c 100644 (file)
--- 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);