From: Stanislav Kinsburskii <stanislav.kinsburskii@gmail.com>

These helper function - virt_to_phys - doesn't need the address pointer to
be mutable.

In the same time expecting it to be mutable leads to the following build
warning for constant pointers:

  warning: passing argument 1 of ‘virt_to_phys’ discards ‘const’ qualifier from pointer target type

Signed-off-by: Stanislav Kinsburskii <stanislav.kinsburskii@gmail.com>
CC: Geert Uytterhoeven <geert@linux-m68k.org>
CC: Helge Deller <deller@gmx.de>
CC: Arnd Bergmann <arnd@arndb.de>
CC: Andrew Morton <akpm@linux-foundation.org>
CC: Bjorn Helgaas <bhelgaas@google.com>
CC: Stanislav Kinsburskii <stanislav.kinsburskii@gmail.com>
CC: linux-ia64@vger.kernel.org
CC: linux-kernel@vger.kernel.org
---
 arch/ia64/include/asm/io.h |    2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/arch/ia64/include/asm/io.h b/arch/ia64/include/asm/io.h
index 83a492c8d298..c56ad21ba1e9 100644
--- a/arch/ia64/include/asm/io.h
+++ b/arch/ia64/include/asm/io.h
@@ -74,7 +74,7 @@ extern unsigned int num_io_spaces;
  * Change virtual addresses to physical addresses and vv.
  */
 static inline unsigned long
-virt_to_phys (volatile void *address)
+virt_to_phys (const volatile void *address)
 {
 	return (unsigned long) address - PAGE_OFFSET;
 }