diff options
| author | Chris Packham | 2023-03-20 10:23:43 +1300 |
|---|---|---|
| committer | Tom Rini | 2023-03-30 15:09:59 -0400 |
| commit | b5f045e12fea0a64a3749c4da1bdfd579530b67e (patch) | |
| tree | 80a9d7bee027eac1f34c6d17c7ad2400d7cc87b0 /include/linux/kernel.h | |
| parent | d87bdb82eae66512c222fd93280acaf4dd1cd4be (diff) | |
include: kernel.h: port find_closest() from Linux
The find_closest() macro can be used to find an element in a sorted
array that is closest to an input value. Bring in this macro from
Linux v6.3-rc1-2-g8ca09d5fa354.
Signed-off-by: Chris Packham <judge.packham@gmail.com>
Reviewed-by: Simon Glass <sjg@chromium.org>
Diffstat (limited to 'include/linux/kernel.h')
| -rw-r--r-- | include/linux/kernel.h | 24 |
1 files changed, 24 insertions, 0 deletions
diff --git a/include/linux/kernel.h b/include/linux/kernel.h index 3e71d61074b..5cd6c9dc821 100644 --- a/include/linux/kernel.h +++ b/include/linux/kernel.h @@ -284,4 +284,28 @@ offsetof(struct structure, member) == (offset), \ "`struct " #structure "` offset for `" #member "` is not " #offset) +#define __find_closest(x, a, as, op) \ +({ \ + typeof(as) __fc_i, __fc_as = (as) - 1; \ + typeof(x) __fc_x = (x); \ + typeof(*a) const *__fc_a = (a); \ + for (__fc_i = 0; __fc_i < __fc_as; __fc_i++) { \ + if (__fc_x op DIV_ROUND_CLOSEST(__fc_a[__fc_i] + \ + __fc_a[__fc_i + 1], 2)) \ + break; \ + } \ + (__fc_i); \ +}) + +/** + * find_closest - locate the closest element in a sorted array + * @x: The reference value. + * @a: The array in which to look for the closest element. Must be sorted + * in ascending order. + * @as: Size of 'a'. + * + * Returns the index of the element closest to 'x'. + */ +#define find_closest(x, a, as) __find_closest(x, a, as, <=) + #endif |