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![Vincenzo Frascino](/assets/img/avatar_default.png)
The vDSO library should only include the necessary headers required for a userspace library (UAPI and a minimal set of kernel headers). To make this possible it is necessary to isolate from the kernel headers the common parts that are strictly necessary to build the library. Split math64.h into linux and common headers to make the latter suitable for inclusion in the vDSO library. Signed-off-by: Vincenzo Frascino <vincenzo.frascino@arm.com> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Link: https://lkml.kernel.org/r/20200320145351.32292-10-vincenzo.frascino@arm.com
282 lines
6.5 KiB
C
282 lines
6.5 KiB
C
/* SPDX-License-Identifier: GPL-2.0 */
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#ifndef _LINUX_MATH64_H
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#define _LINUX_MATH64_H
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#include <linux/types.h>
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#include <vdso/math64.h>
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#include <asm/div64.h>
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#if BITS_PER_LONG == 64
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#define div64_long(x, y) div64_s64((x), (y))
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#define div64_ul(x, y) div64_u64((x), (y))
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/**
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* div_u64_rem - unsigned 64bit divide with 32bit divisor with remainder
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* @dividend: unsigned 64bit dividend
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* @divisor: unsigned 32bit divisor
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* @remainder: pointer to unsigned 32bit remainder
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*
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* Return: sets ``*remainder``, then returns dividend / divisor
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*
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* This is commonly provided by 32bit archs to provide an optimized 64bit
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* divide.
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*/
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static inline u64 div_u64_rem(u64 dividend, u32 divisor, u32 *remainder)
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{
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*remainder = dividend % divisor;
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return dividend / divisor;
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}
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/**
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* div_s64_rem - signed 64bit divide with 32bit divisor with remainder
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* @dividend: signed 64bit dividend
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* @divisor: signed 32bit divisor
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* @remainder: pointer to signed 32bit remainder
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*
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* Return: sets ``*remainder``, then returns dividend / divisor
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*/
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static inline s64 div_s64_rem(s64 dividend, s32 divisor, s32 *remainder)
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{
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*remainder = dividend % divisor;
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return dividend / divisor;
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}
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/**
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* div64_u64_rem - unsigned 64bit divide with 64bit divisor and remainder
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* @dividend: unsigned 64bit dividend
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* @divisor: unsigned 64bit divisor
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* @remainder: pointer to unsigned 64bit remainder
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*
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* Return: sets ``*remainder``, then returns dividend / divisor
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*/
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static inline u64 div64_u64_rem(u64 dividend, u64 divisor, u64 *remainder)
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{
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*remainder = dividend % divisor;
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return dividend / divisor;
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}
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/**
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* div64_u64 - unsigned 64bit divide with 64bit divisor
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* @dividend: unsigned 64bit dividend
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* @divisor: unsigned 64bit divisor
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*
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* Return: dividend / divisor
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*/
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static inline u64 div64_u64(u64 dividend, u64 divisor)
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{
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return dividend / divisor;
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}
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/**
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* div64_s64 - signed 64bit divide with 64bit divisor
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* @dividend: signed 64bit dividend
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* @divisor: signed 64bit divisor
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*
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* Return: dividend / divisor
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*/
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static inline s64 div64_s64(s64 dividend, s64 divisor)
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{
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return dividend / divisor;
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}
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#elif BITS_PER_LONG == 32
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#define div64_long(x, y) div_s64((x), (y))
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#define div64_ul(x, y) div_u64((x), (y))
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#ifndef div_u64_rem
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static inline u64 div_u64_rem(u64 dividend, u32 divisor, u32 *remainder)
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{
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*remainder = do_div(dividend, divisor);
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return dividend;
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}
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#endif
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#ifndef div_s64_rem
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extern s64 div_s64_rem(s64 dividend, s32 divisor, s32 *remainder);
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#endif
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#ifndef div64_u64_rem
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extern u64 div64_u64_rem(u64 dividend, u64 divisor, u64 *remainder);
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#endif
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#ifndef div64_u64
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extern u64 div64_u64(u64 dividend, u64 divisor);
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#endif
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#ifndef div64_s64
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extern s64 div64_s64(s64 dividend, s64 divisor);
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#endif
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#endif /* BITS_PER_LONG */
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/**
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* div_u64 - unsigned 64bit divide with 32bit divisor
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* @dividend: unsigned 64bit dividend
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* @divisor: unsigned 32bit divisor
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*
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* This is the most common 64bit divide and should be used if possible,
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* as many 32bit archs can optimize this variant better than a full 64bit
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* divide.
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*/
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#ifndef div_u64
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static inline u64 div_u64(u64 dividend, u32 divisor)
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{
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u32 remainder;
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return div_u64_rem(dividend, divisor, &remainder);
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}
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#endif
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/**
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* div_s64 - signed 64bit divide with 32bit divisor
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* @dividend: signed 64bit dividend
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* @divisor: signed 32bit divisor
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*/
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#ifndef div_s64
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static inline s64 div_s64(s64 dividend, s32 divisor)
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{
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s32 remainder;
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return div_s64_rem(dividend, divisor, &remainder);
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}
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#endif
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u32 iter_div_u64_rem(u64 dividend, u32 divisor, u64 *remainder);
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#ifndef mul_u32_u32
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/*
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* Many a GCC version messes this up and generates a 64x64 mult :-(
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*/
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static inline u64 mul_u32_u32(u32 a, u32 b)
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{
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return (u64)a * b;
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}
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#endif
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#if defined(CONFIG_ARCH_SUPPORTS_INT128) && defined(__SIZEOF_INT128__)
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#ifndef mul_u64_u32_shr
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static inline u64 mul_u64_u32_shr(u64 a, u32 mul, unsigned int shift)
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{
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return (u64)(((unsigned __int128)a * mul) >> shift);
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}
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#endif /* mul_u64_u32_shr */
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#ifndef mul_u64_u64_shr
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static inline u64 mul_u64_u64_shr(u64 a, u64 mul, unsigned int shift)
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{
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return (u64)(((unsigned __int128)a * mul) >> shift);
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}
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#endif /* mul_u64_u64_shr */
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#else
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#ifndef mul_u64_u32_shr
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static inline u64 mul_u64_u32_shr(u64 a, u32 mul, unsigned int shift)
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{
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u32 ah, al;
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u64 ret;
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al = a;
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ah = a >> 32;
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ret = mul_u32_u32(al, mul) >> shift;
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if (ah)
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ret += mul_u32_u32(ah, mul) << (32 - shift);
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return ret;
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}
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#endif /* mul_u64_u32_shr */
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#ifndef mul_u64_u64_shr
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static inline u64 mul_u64_u64_shr(u64 a, u64 b, unsigned int shift)
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{
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union {
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u64 ll;
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struct {
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#ifdef __BIG_ENDIAN
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u32 high, low;
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#else
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u32 low, high;
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#endif
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} l;
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} rl, rm, rn, rh, a0, b0;
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u64 c;
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a0.ll = a;
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b0.ll = b;
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rl.ll = mul_u32_u32(a0.l.low, b0.l.low);
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rm.ll = mul_u32_u32(a0.l.low, b0.l.high);
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rn.ll = mul_u32_u32(a0.l.high, b0.l.low);
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rh.ll = mul_u32_u32(a0.l.high, b0.l.high);
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/*
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* Each of these lines computes a 64-bit intermediate result into "c",
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* starting at bits 32-95. The low 32-bits go into the result of the
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* multiplication, the high 32-bits are carried into the next step.
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*/
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rl.l.high = c = (u64)rl.l.high + rm.l.low + rn.l.low;
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rh.l.low = c = (c >> 32) + rm.l.high + rn.l.high + rh.l.low;
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rh.l.high = (c >> 32) + rh.l.high;
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/*
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* The 128-bit result of the multiplication is in rl.ll and rh.ll,
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* shift it right and throw away the high part of the result.
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*/
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if (shift == 0)
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return rl.ll;
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if (shift < 64)
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return (rl.ll >> shift) | (rh.ll << (64 - shift));
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return rh.ll >> (shift & 63);
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}
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#endif /* mul_u64_u64_shr */
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#endif
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#ifndef mul_u64_u32_div
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static inline u64 mul_u64_u32_div(u64 a, u32 mul, u32 divisor)
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{
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union {
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u64 ll;
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struct {
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#ifdef __BIG_ENDIAN
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u32 high, low;
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#else
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u32 low, high;
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#endif
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} l;
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} u, rl, rh;
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u.ll = a;
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rl.ll = mul_u32_u32(u.l.low, mul);
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rh.ll = mul_u32_u32(u.l.high, mul) + rl.l.high;
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/* Bits 32-63 of the result will be in rh.l.low. */
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rl.l.high = do_div(rh.ll, divisor);
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/* Bits 0-31 of the result will be in rl.l.low. */
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do_div(rl.ll, divisor);
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rl.l.high = rh.l.low;
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return rl.ll;
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}
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#endif /* mul_u64_u32_div */
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#define DIV64_U64_ROUND_UP(ll, d) \
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({ u64 _tmp = (d); div64_u64((ll) + _tmp - 1, _tmp); })
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/**
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* DIV64_U64_ROUND_CLOSEST - unsigned 64bit divide with 64bit divisor rounded to nearest integer
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* @dividend: unsigned 64bit dividend
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* @divisor: unsigned 64bit divisor
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*
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* Divide unsigned 64bit dividend by unsigned 64bit divisor
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* and round to closest integer.
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*
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* Return: dividend / divisor rounded to nearest integer
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*/
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#define DIV64_U64_ROUND_CLOSEST(dividend, divisor) \
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({ u64 _tmp = (divisor); div64_u64((dividend) + _tmp / 2, _tmp); })
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#endif /* _LINUX_MATH64_H */
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