generic: make PFN_PHYS explicitly return phys_addr_t

PFN_PHYS, as its name suggests, turns a pfn into a physical address.
However, it is a macro which just operates on its argument without
modifying its type.  pfns are typed unsigned long, but an unsigned
long may not be long enough to hold a physical address (32-bit systems
with more than 32 bits of physcial address).

Make sure we cast to phys_addr_t to return a complete result.

Signed-off-by: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>

1 files changed, 5 insertions, 1 deletions

diff --git a/include/linux/pfn.h b/include/linux/pfn.h
index bb01f8b92b56..7646637221f3 100644
--- a/include/linux/pfn.h
+++ b/include/linux/pfn.h
@@ -1,9 +1,13 @@
 #ifndef _LINUX_PFN_H_
 #define _LINUX_PFN_H_
 
+#ifndef __ASSEMBLY__
+#include <linux/types.h>
+#endif
+
 #define PFN_ALIGN(x)    (((unsigned long)(x) + (PAGE_SIZE - 1)) & PAGE_MASK)
 #define PFN_UP(x)       (((x) + PAGE_SIZE-1) >> PAGE_SHIFT)
 #define PFN_DOWN(x)     ((x) >> PAGE_SHIFT)
-#define PFN_PHYS(x)     ((x) << PAGE_SHIFT)
+#define PFN_PHYS(x)     ((phys_addr_t)(x) << PAGE_SHIFT)
 
 #endif