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/* SPDX-License-Identifier: GPL-2.0 */ #ifndef _LINUX_MATH64_H #define _LINUX_MATH64_H #include <linux/types.h> #include <linux/math.h> #include <vdso/math64.h> #include <asm/div64.h> #if BITS_PER_LONG == 64 #define div64_long(x, y) div64_s64((x), (y)) #define div64_ul(x, y) div64_u64((x), (y)) /** * 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. */ static inline u64 div_u64_rem(u64 dividend, u32 divisor, u32 *remainder) { *remainder = dividend % divisor; return dividend / divisor; } /** * 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) { *remainder = dividend % divisor; return dividend / divisor; } /** * 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) { *remainder = dividend % divisor; return dividend / divisor; } /** * 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) { return dividend / 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) { return dividend / divisor; } #elif BITS_PER_LONG == 32 #define div64_long(x, y) div_s64((x), (y)) #define div64_ul(x, y) div_u64((x), (y)) #ifndef div_u64_rem static inline u64 div_u64_rem(u64 dividend, u32 divisor, u32 *remainder) { *remainder = do_div(dividend, divisor); return dividend; } #endif #ifndef div_s64_rem extern s64 div_s64_rem(s64 dividend, s32 divisor, s32 *remainder); #endif #ifndef div64_u64_rem extern u64 div64_u64_rem(u64 dividend, u64 divisor, u64 *remainder); #endif #ifndef div64_u64 extern u64 div64_u64(u64 dividend, u64 divisor); #endif #ifndef div64_s64 extern s64 div64_s64(s64 dividend, s64 divisor); #endif #endif /* BITS_PER_LONG */ /** * 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) { u32 remainder; return div_u64_rem(dividend, divisor, &remainder); } #endif /** * 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) { s32 remainder; return div_s64_rem(dividend, divisor, &remainder); } #endif u32 iter_div_u64_rem(u64 dividend, u32 divisor, u64 *remainder); #ifndef mul_u32_u32 /* * Many a GCC version messes this up and generates a 64x64 mult :-( */ static inline u64 mul_u32_u32(u32 a, u32 b) { return (u64)a * b; } #endif #if defined(CONFIG_ARCH_SUPPORTS_INT128) && defined(__SIZEOF_INT128__) #ifndef mul_u64_u32_shr static __always_inline u64 mul_u64_u32_shr(u64 a, u32 mul, unsigned int shift) { return (u64)(((unsigned __int128)a * mul) >> shift); } #endif /* mul_u64_u32_shr */ #ifndef mul_u64_u64_shr static __always_inline u64 mul_u64_u64_shr(u64 a, u64 mul, unsigned int shift) { return (u64)(((unsigned __int128)a * mul) >> shift); } #endif /* mul_u64_u64_shr */ #else #ifndef mul_u64_u32_shr static __always_inline u64 mul_u64_u32_shr(u64 a, u32 mul, unsigned int shift) { u32 ah, al; u64 ret; al = a; ah = a >> 32; ret = mul_u32_u32(al, mul) >> shift; if (ah) ret += mul_u32_u32(ah, mul) << (32 - shift); return ret; } #endif /* mul_u64_u32_shr */ #ifndef mul_u64_u64_shr static inline u64 mul_u64_u64_shr(u64 a, u64 b, unsigned int shift) { union { u64 ll; struct { #ifdef __BIG_ENDIAN u32 high, low; #else u32 low, high; #endif } l; } rl, rm, rn, rh, a0, b0; u64 c; a0.ll = a; b0.ll = b; rl.ll = mul_u32_u32(a0.l.low, b0.l.low); rm.ll = mul_u32_u32(a0.l.low, b0.l.high); rn.ll = mul_u32_u32(a0.l.high, b0.l.low); rh.ll = mul_u32_u32(a0.l.high, b0.l.high); /* * Each of these lines computes a 64-bit intermediate result into "c", * starting at bits 32-95. The low 32-bits go into the result of the * multiplication, the high 32-bits are carried into the next step. */ rl.l.high = c = (u64)rl.l.high + rm.l.low + rn.l.low; rh.l.low = c = (c >> 32) + rm.l.high + rn.l.high + rh.l.low; rh.l.high = (c >> 32) + rh.l.high; /* * The 128-bit result of the multiplication is in rl.ll and rh.ll, * shift it right and throw away the high part of the result. */ if (shift == 0) return rl.ll; if (shift < 64) return (rl.ll >> shift) | (rh.ll << (64 - shift)); return rh.ll >> (shift & 63); } #endif /* mul_u64_u64_shr */ #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) { union { u64 ll; struct { #ifdef __BIG_ENDIAN u32 high, low; #else u32 low, high; #endif } l; } u, rl, rh; u.ll = a; rl.ll = mul_u32_u32(u.l.low, mul); rh.ll = mul_u32_u32(u.l.high, mul) + rl.l.high; /* Bits 32-63 of the result will be in rh.l.low. */ rl.l.high = do_div(rh.ll, divisor); /* Bits 0-31 of the result will be in rl.l.low. */ do_div(rl.ll, divisor); rl.l.high = rh.l.low; return rl.ll; } #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 */