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| author | Rob Herring <robh@kernel.org> | 2021-04-14 18:54:09 +0300 |
|---|---|---|
| committer | Arnaldo Carvalho de Melo <acme@redhat.com> | 2021-04-15 22:38:02 +0300 |
| commit | 2fc83c2cd77703cfcfc1ffaa092614fb1f837292 (patch) | |
| tree | 89f326cf79bb774df2d36ed699dc41684cdb1d75 /init/do_mounts.h | |
| parent | 2e1daee14e67fbf9b27280b974e2c680a22cabea (diff) | |
| download | linux-2fc83c2cd77703cfcfc1ffaa092614fb1f837292.tar.xz | |
tools include: Add an initial math64.h
Add an initial math64.h similar to linux/math64.h with functions
mul_u64_u64_div64() and mul_u64_u32_shr(). This isn't a direct copy of
include/linux/math64.h as that doesn't define mul_u64_u64_div64().
Implementation was written by Peter Zilkstra based on linux/math64.h
and div64.h[1]. The original implementation was not optimal on arm64 as
__int128 division is not optimal with a call out to __udivti3, so I
dropped the __int128 variant of mul_u64_u64_div64().
[1] https://lore.kernel.org/lkml/20200322101848.GF2452@worktop.programming.kicks-ass.net/
Signed-off-by: Rob Herring <robh@kernel.org>
Acked-by: Jiri Olsa <jolsa@redhat.com>
Acked-by: Namhyung Kim <namhyung@kernel.org>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Itaru Kitayama <itaru.kitayama@gmail.com>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Will Deacon <will@kernel.org>
Link: http://lore.kernel.org/lkml/20210414155412.3697605-2-robh@kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Diffstat (limited to 'init/do_mounts.h')
0 files changed, 0 insertions, 0 deletions