270 lines
6.1 KiB
C
270 lines
6.1 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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#endif /* _LINUX_MATH64_H */
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