# \[PATCH v3 4/4\] virtio: pci: Constify ioreadX() iomem argument (as in generic implementation)

- From: Krzysztof Kozlowski \<krzk@kernel.org\>
- Date: 2020-07-09 07:29:24 
- List: linuxppc-dev
- Page: https://ratatoskr.run/linuxppc-dev/2020/07/6030229
- Thread: https://ratatoskr.run/linux-alpha/2020/07/6030229/t.md

```text
The ioreadX() helpers have inconsistent interface.  On some architectures
void *__iomem address argument is a pointer to const, on some not.

Implementations of ioreadX() do not modify the memory under the address
so they can be converted to a "const" version for const-safety and
consistency among architectures.

Signed-off-by: Krzysztof Kozlowski <krzk@kernel.org>
Reviewed-by: Geert Uytterhoeven <geert+renesas@glider.be>
---
 drivers/virtio/virtio_pci_modern.c | 6 +++---
 1 file changed, 3 insertions(+), 3 deletions(-)

diff --git a/drivers/virtio/virtio_pci_modern.c b/drivers/virtio/virtio_pci_modern.c
index db93cedd262f..90eff165a719 100644
--- a/drivers/virtio/virtio_pci_modern.c
+++ b/drivers/virtio/virtio_pci_modern.c
@@ -27,16 +27,16 @@
  * method, i.e. 32-bit accesses for 32-bit fields, 16-bit accesses
  * for 16-bit fields and 8-bit accesses for 8-bit fields.
  */
-static inline u8 vp_ioread8(u8 __iomem *addr)
+static inline u8 vp_ioread8(const u8 __iomem *addr)
 {
 	return ioread8(addr);
 }
-static inline u16 vp_ioread16 (__le16 __iomem *addr)
+static inline u16 vp_ioread16 (const __le16 __iomem *addr)
 {
 	return ioread16(addr);
 }
 
-static inline u32 vp_ioread32(__le32 __iomem *addr)
+static inline u32 vp_ioread32(const __le32 __iomem *addr)
 {
 	return ioread32(addr);
 }
-- 
2.17.1

```
