From eb18cba78c2b9250663021e17e1e9cc34630e92a Mon Sep 17 00:00:00 2001 From: Mike Snitzer Date: Tue, 20 Aug 2013 15:05:17 -0400 Subject: math64: New separate div64_u64_rem helper Commit f792685006274a850e6cc0ea9ade275ccdfc90bc ("math64: New div64_u64_rem helper") implemented div64_u64 in terms of div64_u64_rem. But div64_u64_rem was removed because it slowed down div64_u64 (and there were no other users of div64_u64_rem). Device Mapper's I/O statistics support has a need for div64_u64_rem; reintroduce this helper as a separate method that doesn't slow down div64_u64, especially on 32-bit systems. Signed-off-by: Mike Snitzer Cc: Stanislaw Gruszka Cc: Ingo Molnar Cc: Frederic Weisbecker Cc: Mikulas Patocka Signed-off-by: Alasdair G Kergon --- include/linux/math64.h | 13 +++++++++++++ 1 file changed, 13 insertions(+) (limited to 'include/linux/math64.h') diff --git a/include/linux/math64.h b/include/linux/math64.h index 2913b86eb12a..69ed5f5e9f6e 100644 --- a/include/linux/math64.h +++ b/include/linux/math64.h @@ -30,6 +30,15 @@ static inline s64 div_s64_rem(s64 dividend, s32 divisor, s32 *remainder) return dividend / divisor; } +/** + * div64_u64_rem - unsigned 64bit divide with 64bit divisor and remainder + */ +static inline u64 div64_u64_rem(u64 dividend, u64 divisor, u64 *remainder) +{ + *remainder = dividend % divisor; + return dividend / divisor; +} + /** * div64_u64 - unsigned 64bit divide with 64bit divisor */ @@ -63,6 +72,10 @@ static inline u64 div_u64_rem(u64 dividend, u32 divisor, u32 *remainder) extern s64 div_s64_rem(s64 dividend, s32 divisor, s32 *remainder); #endif +#ifndef div64_u64_rem +extern u64 div64_u64_rem(u64 dividend, u64 divisor, u64 *remainder); +#endif + #ifndef div64_u64 extern u64 div64_u64(u64 dividend, u64 divisor); #endif -- cgit v1.2.3