virtio: Don't use PAGE_SIZE in virtio_pci.c
The virtio PCI devices don't depend on the guest page size. This matters
now PowerPC virtio is gaining ground (they like 64k pages).
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
diff --git a/drivers/virtio/virtio_pci.c b/drivers/virtio/virtio_pci.c
index e37d686..c2cd69b 100644
--- a/drivers/virtio/virtio_pci.c
+++ b/drivers/virtio/virtio_pci.c
@@ -245,7 +245,7 @@
}
/* activate the queue */
- iowrite32(virt_to_phys(info->queue) >> PAGE_SHIFT,
+ iowrite32(virt_to_phys(info->queue) >> VIRTIO_PCI_QUEUE_ADDR_SHIFT,
vp_dev->ioaddr + VIRTIO_PCI_QUEUE_PFN);
/* create the vring */
diff --git a/include/linux/virtio_pci.h b/include/linux/virtio_pci.h
index cdef357..e13d7eb 100644
--- a/include/linux/virtio_pci.h
+++ b/include/linux/virtio_pci.h
@@ -53,4 +53,8 @@
/* Virtio ABI version, this must match exactly */
#define VIRTIO_PCI_ABI_VERSION 0
+
+/* How many bits to shift physical queue address written to QUEUE_PFN.
+ * 12 is historical, and due to x86 page size. */
+#define VIRTIO_PCI_QUEUE_ADDR_SHIFT 12
#endif