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authorChunyan Zhang <chunyan.zhang@unisoc.com>2020-07-24 15:21:47 +0300
committerSebastian Reichel <sebastian.reichel@collabora.com>2020-07-28 01:47:18 +0300
commitaf60459a543483c5ad155a92daa8c3a6c00a0829 (patch)
tree7c38ee31d9ee6f37e750033a6df3ca2094ff7187 /include/linux/math64.h
parentab92ffd5f6ac3ebd4a7650ef906702ab86127b45 (diff)
downloadlinux-af60459a543483c5ad155a92daa8c3a6c00a0829.tar.xz
math64: New DIV_S64_ROUND_CLOSEST helper
Provide DIV_S64_ROUND_CLOSEST helper which uses div_s64 to perform division rounded to the closest integer using signed 64bit dividend and signed 32bit divisor. Signed-off-by: Chunyan Zhang <chunyan.zhang@unisoc.com> Signed-off-by: Sebastian Reichel <sebastian.reichel@collabora.com>
Diffstat (limited to 'include/linux/math64.h')
-rw-r--r--include/linux/math64.h19
1 files changed, 19 insertions, 0 deletions
diff --git a/include/linux/math64.h b/include/linux/math64.h
index 11a267413e8e..cd0693989436 100644
--- a/include/linux/math64.h
+++ b/include/linux/math64.h
@@ -279,4 +279,23 @@ static inline u64 mul_u64_u32_div(u64 a, u32 mul, u32 divisor)
#define DIV64_U64_ROUND_CLOSEST(dividend, divisor) \
({ u64 _tmp = (divisor); div64_u64((dividend) + _tmp / 2, _tmp); })
+/*
+ * DIV_S64_ROUND_CLOSEST - signed 64bit divide with 32bit divisor rounded to nearest integer
+ * @dividend: signed 64bit dividend
+ * @divisor: signed 32bit divisor
+ *
+ * Divide signed 64bit dividend by signed 32bit divisor
+ * and round to closest integer.
+ *
+ * Return: dividend / divisor rounded to nearest integer
+ */
+#define DIV_S64_ROUND_CLOSEST(dividend, divisor)( \
+{ \
+ s64 __x = (dividend); \
+ s32 __d = (divisor); \
+ ((__x > 0) == (__d > 0)) ? \
+ div_s64((__x + (__d / 2)), __d) : \
+ div_s64((__x - (__d / 2)), __d); \
+} \
+)
#endif /* _LINUX_MATH64_H */