[PATCH 17/26] lib: div64: sync with Linux

[Dario Binacchi]

From: Michael Trimarchi <michael at amarulasolutions.com>

Sync with Linux commit fc4a0db4149af ("Merge tag '6.5'").

Signed-off-by: Michael Trimarchi <michael at amarulasolutions.com>
Signed-off-by: Dario Binacchi <dario.binacchi at amarulasolutions.com>
---

 include/linux/math64.h | 110 +++++++++++++++++++++++++++++++++++++++++
 1 file changed, 110 insertions(+)

diff --git a/include/linux/math64.h b/include/linux/math64.h
index eaa9fd5b9685..82bd7472a32c 100644
--- a/include/linux/math64.h
+++ b/include/linux/math64.h
@@ -1,3 +1,4 @@
+/* SPDX-License-Identifier: GPL-2.0 */
 #ifndef _LINUX_MATH64_H
 #define _LINUX_MATH64_H
 
@@ -12,6 +13,11 @@
 
 /**
  * div_u64_rem - unsigned 64bit divide with 32bit divisor with remainder
+ * @dividend: unsigned 64bit dividend
+ * @divisor: unsigned 32bit divisor
+ * @remainder: pointer to unsigned 32bit remainder
+ *
+ * Return: sets ``*remainder``, then returns dividend / divisor
  *
  * This is commonly provided by 32bit archs to provide an optimized 64bit
  * divide.
@@ -24,6 +30,11 @@ static inline u64 div_u64_rem(u64 dividend, u32 divisor, u32 *remainder)
 
 /**
  * div_s64_rem - signed 64bit divide with 32bit divisor with remainder
+ * @dividend: signed 64bit dividend
+ * @divisor: signed 32bit divisor
+ * @remainder: pointer to signed 32bit remainder
+ *
+ * Return: sets ``*remainder``, then returns dividend / divisor
  */
 static inline s64 div_s64_rem(s64 dividend, s32 divisor, s32 *remainder)
 {
@@ -33,6 +44,11 @@ static inline s64 div_s64_rem(s64 dividend, s32 divisor, s32 *remainder)
 
 /**
  * div64_u64_rem - unsigned 64bit divide with 64bit divisor and remainder
+ * @dividend: unsigned 64bit dividend
+ * @divisor: unsigned 64bit divisor
+ * @remainder: pointer to unsigned 64bit remainder
+ *
+ * Return: sets ``*remainder``, then returns dividend / divisor
  */
 static inline u64 div64_u64_rem(u64 dividend, u64 divisor, u64 *remainder)
 {
@@ -42,6 +58,10 @@ static inline u64 div64_u64_rem(u64 dividend, u64 divisor, u64 *remainder)
 
 /**
  * div64_u64 - unsigned 64bit divide with 64bit divisor
+ * @dividend: unsigned 64bit dividend
+ * @divisor: unsigned 64bit divisor
+ *
+ * Return: dividend / divisor
  */
 static inline u64 div64_u64(u64 dividend, u64 divisor)
 {
@@ -53,6 +73,10 @@ static inline u64 div64_u64(u64 dividend, u64 divisor)
 
 /**
  * div64_s64 - signed 64bit divide with 64bit divisor
+ * @dividend: signed 64bit dividend
+ * @divisor: signed 64bit divisor
+ *
+ * Return: dividend / divisor
  */
 static inline s64 div64_s64(s64 dividend, s64 divisor)
 {
@@ -92,10 +116,14 @@ extern s64 div64_s64(s64 dividend, s64 divisor);
 
 /**
  * div_u64 - unsigned 64bit divide with 32bit divisor
+ * @dividend: unsigned 64bit dividend
+ * @divisor: unsigned 32bit divisor
  *
  * This is the most common 64bit divide and should be used if possible,
  * as many 32bit archs can optimize this variant better than a full 64bit
  * divide.
+ *
+ * Return: dividend / divisor
  */
 #ifndef div_u64
 static inline u64 div_u64(u64 dividend, u32 divisor)
@@ -107,6 +135,10 @@ static inline u64 div_u64(u64 dividend, u32 divisor)
 
 /**
  * div_s64 - signed 64bit divide with 32bit divisor
+ * @dividend: signed 64bit dividend
+ * @divisor: signed 32bit divisor
+ *
+ * Return: dividend / divisor
  */
 #ifndef div_s64
 static inline s64 div_s64(s64 dividend, s32 divisor)
@@ -228,6 +260,24 @@ static inline u64 mul_u64_u64_shr(u64 a, u64 b, unsigned int shift)
 
 #endif
 
+#ifndef mul_s64_u64_shr
+static inline u64 mul_s64_u64_shr(s64 a, u64 b, unsigned int shift)
+{
+	u64 ret;
+
+	/*
+	 * Extract the sign before the multiplication and put it back
+	 * afterwards if needed.
+	 */
+	ret = mul_u64_u64_shr(abs(a), b, shift);
+
+	if (a < 0)
+		ret = -((s64)ret);
+
+	return ret;
+}
+#endif /* mul_s64_u64_shr */
+
 #ifndef mul_u64_u32_div
 static inline u64 mul_u64_u32_div(u64 a, u32 mul, u32 divisor)
 {
@@ -257,4 +307,64 @@ static inline u64 mul_u64_u32_div(u64 a, u32 mul, u32 divisor)
 }
 #endif /* mul_u64_u32_div */
 
+u64 mul_u64_u64_div_u64(u64 a, u64 mul, u64 div);
+
+/**
+ * DIV64_U64_ROUND_UP - unsigned 64bit divide with 64bit divisor rounded up
+ * @ll: unsigned 64bit dividend
+ * @d: unsigned 64bit divisor
+ *
+ * Divide unsigned 64bit dividend by unsigned 64bit divisor
+ * and round up.
+ *
+ * Return: dividend / divisor rounded up
+ */
+#define DIV64_U64_ROUND_UP(ll, d)	\
+	({ u64 _tmp = (d); div64_u64((ll) + _tmp - 1, _tmp); })
+
+/**
+ * DIV64_U64_ROUND_CLOSEST - unsigned 64bit divide with 64bit divisor rounded to nearest integer
+ * @dividend: unsigned 64bit dividend
+ * @divisor: unsigned 64bit divisor
+ *
+ * Divide unsigned 64bit dividend by unsigned 64bit divisor
+ * and round to closest integer.
+ *
+ * Return: dividend / divisor rounded to nearest integer
+ */
+#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
+ * @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 */
-- 
2.43.0