math: Introduce div64_long

Add a div64_long macro which is used to devide a 64bit number by a long (which
can be 4 bytes on 32bit systems and 8 bytes on 64bit systems).

Suggested-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Sasha Levin <levinsasha928@gmail.com>
Cc: johnstul@us.ibm.com
Link: http://lkml.kernel.org/r/1331829374-31543-1-git-send-email-levinsasha928@gmail.com
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>

include/linux/math64.h

@@ -6,6 +6,8 @@
 
 #if BITS_PER_LONG == 64
 
+#define div64_long(x,y) div64_s64((x),(y))
+
 /**
  * div_u64_rem - unsigned 64bit divide with 32bit divisor with remainder
  *
@@ -45,6 +47,8 @@ static inline s64 div64_s64(s64 dividend, s64 divisor)
 
 #elif BITS_PER_LONG == 32
 
+#define div64_long(x,y) div_s64((x),(y))
+
 #ifndef div_u64_rem
 static inline u64 div_u64_rem(u64 dividend, u32 divisor, u32 *remainder)
 {