sgi-xp: define BYTES_PER_WORD

Add a BYTES_PER_WORD #define.

Signed-off-by: Dean Nelson <dcn@sgi.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
diff --git a/drivers/misc/sgi-xp/xp.h b/drivers/misc/sgi-xp/xp.h
index 21cb8a3..867fb48 100644
--- a/drivers/misc/sgi-xp/xp.h
+++ b/drivers/misc/sgi-xp/xp.h
@@ -19,6 +19,9 @@
 #include <asm/sn/types.h>
 #include <asm/sn/bte.h>
 
+/* >>> Add this #define to some linux header file some day. */
+#define BYTES_PER_WORD	sizeof(void *)
+
 #ifdef USE_DBUG_ON
 #define DBUG_ON(condition)	BUG_ON(condition)
 #else