diff options
| author | Jiri Kosina <jkosina@suse.cz> | 2013-12-19 15:08:03 +0100 |
|---|---|---|
| committer | Jiri Kosina <jkosina@suse.cz> | 2013-12-19 15:08:32 +0100 |
| commit | e23c34bb41da65f354fb7eee04300c56ee48f60c (patch) | |
| tree | 549fbe449d55273b81ef104a9755109bf4ae7817 /lib/div64.c | |
| parent | b481c2cb3534c85dca625973b33eba15f9af3e4c (diff) | |
| parent | 319e2e3f63c348a9b66db4667efa73178e18b17d (diff) | |
Merge branch 'master' into for-next
Sync with Linus' tree to be able to apply fixes on top of newer things
in tree (efi-stub).
Signed-off-by: Jiri Kosina <jkosina@suse.cz>
Diffstat (limited to 'lib/div64.c')
| -rw-r--r-- | lib/div64.c | 40 |
1 files changed, 40 insertions, 0 deletions
diff --git a/lib/div64.c b/lib/div64.c index a163b6caef73..4382ad77777e 100644 --- a/lib/div64.c +++ b/lib/div64.c @@ -79,6 +79,46 @@ EXPORT_SYMBOL(div_s64_rem); #endif /** + * div64_u64_rem - unsigned 64bit divide with 64bit divisor and remainder + * @dividend: 64bit dividend + * @divisor: 64bit divisor + * @remainder: 64bit remainder + * + * This implementation is a comparable to algorithm used by div64_u64. + * But this operation, which includes math for calculating the remainder, + * is kept distinct to avoid slowing down the div64_u64 operation on 32bit + * systems. + */ +#ifndef div64_u64_rem +u64 div64_u64_rem(u64 dividend, u64 divisor, u64 *remainder) +{ + u32 high = divisor >> 32; + u64 quot; + + if (high == 0) { + u32 rem32; + quot = div_u64_rem(dividend, divisor, &rem32); + *remainder = rem32; + } else { + int n = 1 + fls(high); + quot = div_u64(dividend >> n, divisor >> n); + + if (quot != 0) + quot--; + + *remainder = dividend - quot * divisor; + if (*remainder >= divisor) { + quot++; + *remainder -= divisor; + } + } + + return quot; +} +EXPORT_SYMBOL(div64_u64_rem); +#endif + +/** * div64_u64 - unsigned 64bit divide with 64bit divisor * @dividend: 64bit dividend * @divisor: 64bit divisor |
