| /* SPDX-License-Identifier: GPL-2.0 */ |
| #ifndef _LINUX_MATH64_H |
| #define _LINUX_MATH64_H |
| |
| #include <linux/types.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 |
| * |
| * 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 |
| */ |
| 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 |
| */ |
| 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 |
| */ |
| static inline u64 div64_u64(u64 dividend, u64 divisor) |
| { |
| return dividend / divisor; |
| } |
| |
| /** |
| * div64_s64 - signed 64bit divide with 64bit 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 |
| * |
| * 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. |
| */ |
| #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 |
| */ |
| #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); |
| |
| static __always_inline u32 |
| __iter_div_u64_rem(u64 dividend, u32 divisor, u64 *remainder) |
| { |
| u32 ret = 0; |
| |
| while (dividend >= divisor) { |
| /* The following asm() prevents the compiler from |
| optimising this loop into a modulo operation. */ |
| asm("" : "+rm"(dividend)); |
| |
| dividend -= divisor; |
| ret++; |
| } |
| |
| *remainder = dividend; |
| |
| return ret; |
| } |
| |
| #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 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 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 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_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 */ |
| |
| #define DIV64_U64_ROUND_UP(ll, d) \ |
| ({ u64 _tmp = (d); div64_u64((ll) + _tmp - 1, _tmp); }) |
| |
| #endif /* _LINUX_MATH64_H */ |