From 2c861b73a23b1237bdd054b6023bb27f6747c2b9 Mon Sep 17 00:00:00 2001
From: =?utf8?q?Pali=20Roh=C3=A1r?= <pali@kernel.org>
Date: Sat, 19 Feb 2022 16:28:13 +0100
Subject: [PATCH] math64: New DIV_U64_ROUND_CLOSEST helper
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Provide DIV_U64_ROUND_CLOSEST helper which uses div_u64 to perform
division rounded to the closest integer using unsigned 64bit
dividend and unsigned 32bit divisor.
Reviewed-by: Marek Behún <kabel@kernel.org>
Signed-off-by: Pali Rohár <pali@kernel.org>
Signed-off-by: Marek Behún <kabel@kernel.org>
Link: https://lore.kernel.org/r/20220219152818.4319-2-kabel@kernel.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
include/linux/math64.h | 13 +++++++++++++
1 file changed, 13 insertions(+)
diff --git a/include/linux/math64.h b/include/linux/math64.h
index 2928f03d6d46a..a14f40de1dca4 100644
--- a/include/linux/math64.h
+++ b/include/linux/math64.h
@@ -300,6 +300,19 @@ u64 mul_u64_u64_div_u64(u64 a, u64 mul, u64 div);
#define DIV64_U64_ROUND_CLOSEST(dividend, divisor) \
({ u64 _tmp = (divisor); div64_u64((dividend) + _tmp / 2, _tmp); })
+/*
+ * DIV_U64_ROUND_CLOSEST - unsigned 64bit divide with 32bit divisor rounded to nearest integer
+ * @dividend: unsigned 64bit dividend
+ * @divisor: unsigned 32bit divisor
+ *
+ * Divide unsigned 64bit dividend by unsigned 32bit divisor
+ * and round to closest integer.
+ *
+ * Return: dividend / divisor rounded to nearest integer
+ */
+#define DIV_U64_ROUND_CLOSEST(dividend, divisor) \
+ ({ u32 _tmp = (divisor); div_u64((u64)(dividend) + _tmp / 2, _tmp); })
+
/*
* DIV_S64_ROUND_CLOSEST - signed 64bit divide with 32bit divisor rounded to nearest integer
* @dividend: signed 64bit dividend
--
2.30.2