From: Zhang Yi <[email protected]>
Add a new helper rem_u64() to only get the remainder of unsigned 64bit
divide with 32bit divisor.
Signed-off-by: Zhang Yi <[email protected]>
Reviewed-by: Christoph Hellwig <[email protected]>
Reviewed-by: Darrick J. Wong <[email protected]>
---
include/linux/math64.h | 22 ++++++++++++++++++++++
1 file changed, 22 insertions(+)
diff --git a/include/linux/math64.h b/include/linux/math64.h
index d34def7f9a8c..efbe58c157e3 100644
--- a/include/linux/math64.h
+++ b/include/linux/math64.h
@@ -3,6 +3,7 @@
#define _LINUX_MATH64_H
#include <linux/types.h>
+#include <linux/log2.h>
#include <linux/math.h>
#include <asm/div64.h>
#include <vdso/math64.h>
@@ -12,6 +13,20 @@
#define div64_long(x, y) div64_s64((x), (y))
#define div64_ul(x, y) div64_u64((x), (y))
+/**
+ * rem_u64 - remainder of unsigned 64bit divide with 32bit divisor
+ * @dividend: unsigned 64bit dividend
+ * @divisor: unsigned 32bit divisor
+ *
+ * Return: dividend % divisor
+ */
+static inline u32 rem_u64(u64 dividend, u32 divisor)
+{
+ if (is_power_of_2(divisor))
+ return dividend & (divisor - 1);
+ return dividend % divisor;
+}
+
/**
* div_u64_rem - unsigned 64bit divide with 32bit divisor with remainder
* @dividend: unsigned 64bit dividend
@@ -86,6 +101,13 @@ static inline s64 div64_s64(s64 dividend, s64 divisor)
#define div64_long(x, y) div_s64((x), (y))
#define div64_ul(x, y) div_u64((x), (y))
+static inline u32 rem_u64(u64 dividend, u32 divisor)
+{
+ if (is_power_of_2(divisor))
+ return dividend & (divisor - 1);
+ return do_div(dividend, divisor);
+}
+
#ifndef div_u64_rem
static inline u64 div_u64_rem(u64 dividend, u32 divisor, u32 *remainder)
{
--
2.39.2