diff options
| -rw-r--r-- | include/asm-x86/div64.h | 20 | ||||
| -rw-r--r-- | include/linux/math64.h | 72 | ||||
| -rw-r--r-- | lib/div64.c | 23 |
3 files changed, 113 insertions, 2 deletions
diff --git a/include/asm-x86/div64.h b/include/asm-x86/div64.h index 0dbf8bf..c7892cf 100644 --- a/include/asm-x86/div64.h +++ b/include/asm-x86/div64.h @@ -51,6 +51,26 @@ static inline long div_ll_X_l_rem(long long divs, long div, long *rem) } +static inline u64 div_u64_rem(u64 dividend, u32 divisor, u32 *remainder) +{ + union { + u64 v64; + u32 v32[2]; + } d = { dividend }; + u32 upper; + + upper = d.v32[1]; + d.v32[1] = 0; + if (upper >= divisor) { + d.v32[1] = upper / divisor; + upper %= divisor; + } + asm ("divl %2" : "=a" (d.v32[0]), "=d" (*remainder) : + "rm" (divisor), "0" (d.v32[0]), "1" (upper)); + return d.v64; +} +#define div_u64_rem div_u64_rem + extern uint64_t div64_64(uint64_t dividend, uint64_t divisor); #else diff --git a/include/linux/math64.h b/include/linux/math64.h new file mode 100644 index 0000000..6d17166 --- /dev/null +++ b/include/linux/math64.h @@ -0,0 +1,72 @@ +#ifndef _LINUX_MATH64_H +#define _LINUX_MATH64_H + +#include <linux/types.h> +#include <asm/div64.h> + +#if BITS_PER_LONG == 64 + +/** + * 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; +} + +#elif BITS_PER_LONG == 32 + +#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 + +#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 + +#endif /* _LINUX_MATH64_H */ diff --git a/lib/div64.c b/lib/div64.c index b71cf93..689bd76 100644 --- a/lib/div64.c +++ b/lib/div64.c @@ -16,9 +16,8 @@ * assembly versions such as arch/ppc/lib/div64.S and arch/sh/lib/div64.S. */ -#include <linux/types.h> #include <linux/module.h> -#include <asm/div64.h> +#include <linux/math64.h> /* Not needed on 64bit architectures */ #if BITS_PER_LONG == 32 @@ -58,6 +57,26 @@ uint32_t __attribute__((weak)) __div64_32(uint64_t *n, uint32_t base) EXPORT_SYMBOL(__div64_32); +#ifndef div_s64_rem +s64 div_s64_rem(s64 dividend, s32 divisor, s32 *remainder) +{ + u64 quotient; + + if (dividend < 0) { + quotient = div_u64_rem(-dividend, abs(divisor), (u32 *)remainder); + *remainder = -*remainder; + if (divisor > 0) + quotient = -quotient; + } else { + quotient = div_u64_rem(dividend, abs(divisor), (u32 *)remainder); + if (divisor < 0) + quotient = -quotient; + } + return quotient; +} +EXPORT_SYMBOL(div_s64_rem); +#endif + /* 64bit divisor, dividend and result. dynamic precision */ uint64_t div64_64(uint64_t dividend, uint64_t divisor) { |
