Linux Virtualization - May 2021 - [PATCH 1/2] virtio_pci_modern: __force cast the notify mapping

When switching virtio_pci_modern to use a helper for mappings we lost an
__iomem tag. We should restore it.

However, virtio_pci_modern is playing tricks by hiding an iomem pointer
in a regular vq->priv pointer. Which is okay as long as it's
all contained within a single file, but we need to __force cast
the value otherwise we'll get sparse warnings.

Reported-by: kernel test robot <lkp at intel.com>
Fixes: 7dca6c0ea96b ("virtio-pci library: switch to use
vp_modern_map_vq_notify()")
Signed-off-by: Michael S. Tsirkin <mst at redhat.com>
---
 drivers/virtio/virtio_pci_modern.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/virtio/virtio_pci_modern.c
b/drivers/virtio/virtio_pci_modern.c
index 722ea44e7579..30654d3a0b41 100644
--- a/drivers/virtio/virtio_pci_modern.c
+++ b/drivers/virtio/virtio_pci_modern.c
@@ -224,7 +224,7 @@ static struct virtqueue *setup_vq(struct virtio_pci_device
*vp_dev,
 				virtqueue_get_avail_addr(vq),
 				virtqueue_get_used_addr(vq));
 
-	vq->priv = vp_modern_map_vq_notify(mdev, index, NULL);
+	vq->priv = (void __force *)vp_modern_map_vq_notify(mdev, index, NULL);
 	if (!vq->priv) {
 		err = -ENOMEM;
 		goto err_map_notify;
-- 
MST

When switching virtio_pci_modern to use a helper for mappings we lost an
__iomem tag. Restore it.

Reported-by: kernel test robot <lkp at intel.com>
Fixes: 9e3bb9b79a71 ("virtio_pci_modern: introduce helper to map vq notify
area")
Signed-off-by: Michael S. Tsirkin <mst at redhat.com>
---
 drivers/virtio/virtio_pci_modern_dev.c | 9 ++++-----
 include/linux/virtio_pci_modern.h      | 4 ++--
 2 files changed, 6 insertions(+), 7 deletions(-)

diff --git a/drivers/virtio/virtio_pci_modern_dev.c
b/drivers/virtio/virtio_pci_modern_dev.c
index ae87b3fa8858..54f297028586 100644
--- a/drivers/virtio/virtio_pci_modern_dev.c
+++ b/drivers/virtio/virtio_pci_modern_dev.c
@@ -605,8 +605,8 @@ static u16 vp_modern_get_queue_notify_off(struct
virtio_pci_modern_device *mdev,
  *
  * Returns the address of the notification area
  */
-void *vp_modern_map_vq_notify(struct virtio_pci_modern_device *mdev,
-			      u16 index, resource_size_t *pa)
+void __iomem *vp_modern_map_vq_notify(struct virtio_pci_modern_device *mdev,
+				      u16 index, resource_size_t *pa)
 {
 	u16 off = vp_modern_get_queue_notify_off(mdev, index);
 
@@ -624,10 +624,9 @@ void *vp_modern_map_vq_notify(struct
virtio_pci_modern_device *mdev,
 		if (pa)
 			*pa = mdev->notify_pa +
 			      off * mdev->notify_offset_multiplier;
-		return (void __force *)mdev->notify_base +
-			off * mdev->notify_offset_multiplier;
+		return mdev->notify_base + off * mdev->notify_offset_multiplier;
 	} else {
-		return (void __force *)vp_modern_map_capability(mdev,
+		return vp_modern_map_capability(mdev,
 				       mdev->notify_map_cap, 2, 2,
 				       off * mdev->notify_offset_multiplier, 2,
 				       NULL, pa);
diff --git a/include/linux/virtio_pci_modern.h
b/include/linux/virtio_pci_modern.h
index cdfabbefacdf..6a95b58fd0f4 100644
--- a/include/linux/virtio_pci_modern.h
+++ b/include/linux/virtio_pci_modern.h
@@ -101,8 +101,8 @@ void vp_modern_set_queue_size(struct
virtio_pci_modern_device *mdev,
 u16 vp_modern_get_queue_size(struct virtio_pci_modern_device *mdev,
 			     u16 idx);
 u16 vp_modern_get_num_queues(struct virtio_pci_modern_device *mdev);
-void *vp_modern_map_vq_notify(struct virtio_pci_modern_device *mdev,
-                              u16 index, resource_size_t *pa);
+void __iomem * vp_modern_map_vq_notify(struct virtio_pci_modern_device *mdev,
+				       u16 index, resource_size_t *pa);
 int vp_modern_probe(struct virtio_pci_modern_device *mdev);
 void vp_modern_remove(struct virtio_pci_modern_device *mdev);
 #endif
-- 
MST