virtio: pci: constify ioreadX() iomem argument (as in generic implementation)

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 <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
Reviewed-by: Geert Uytterhoeven <[email protected]>
Cc: Allen Hubbe <[email protected]>
Cc: Arnd Bergmann <[email protected]>
Cc: Benjamin Herrenschmidt <[email protected]>
Cc: Dave Jiang <[email protected]>
Cc: "David S. Miller" <[email protected]>
Cc: Geert Uytterhoeven <[email protected]>
Cc: Helge Deller <[email protected]>
Cc: Ivan Kokshaysky <[email protected]>
Cc: Jakub Kicinski <[email protected]>
Cc: "James E.J. Bottomley" <[email protected]>
Cc: Jason Wang <[email protected]>
Cc: Jon Mason <[email protected]>
Cc: Kalle Valo <[email protected]>
Cc: Matt Turner <[email protected]>
Cc: Michael Ellerman <[email protected]>
Cc: "Michael S. Tsirkin" <[email protected]>
Cc: Paul Mackerras <[email protected]>
Cc: Richard Henderson <[email protected]>
Cc: Rich Felker <[email protected]>
Cc: Yoshinori Sato <[email protected]>
Link: http://lkml.kernel.org/r/[email protected]
Signed-off-by: Linus Torvalds <[email protected]>

Author: krzk

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);
 }