| 1 | #ifndef _LINUX_MATH64_H |
| 2 | #define _LINUX_MATH64_H |
| 3 | |
| 4 | #include <linux/types.h> |
| 5 | #include <asm/div64.h> |
| 6 | |
| 7 | #if BITS_PER_LONG == 64 |
| 8 | |
| 9 | /** |
| 10 | * div_u64_rem - unsigned 64bit divide with 32bit divisor with remainder |
| 11 | * |
| 12 | * This is commonly provided by 32bit archs to provide an optimized 64bit |
| 13 | * divide. |
| 14 | */ |
| 15 | static inline u64 div_u64_rem(u64 dividend, u32 divisor, u32 *remainder) |
| 16 | { |
| 17 | *remainder = dividend % divisor; |
| 18 | return dividend / divisor; |
| 19 | } |
| 20 | |
| 21 | /** |
| 22 | * div_s64_rem - signed 64bit divide with 32bit divisor with remainder |
| 23 | */ |
| 24 | static inline s64 div_s64_rem(s64 dividend, s32 divisor, s32 *remainder) |
| 25 | { |
| 26 | *remainder = dividend % divisor; |
| 27 | return dividend / divisor; |
| 28 | } |
| 29 | |
| 30 | /** |
| 31 | * div64_u64 - unsigned 64bit divide with 64bit divisor |
| 32 | */ |
| 33 | static inline u64 div64_u64(u64 dividend, u64 divisor) |
| 34 | { |
| 35 | return dividend / divisor; |
| 36 | } |
| 37 | |
| 38 | /** |
| 39 | * div64_s64 - signed 64bit divide with 64bit divisor |
| 40 | */ |
| 41 | static inline s64 div64_s64(s64 dividend, s64 divisor) |
| 42 | { |
| 43 | return dividend / divisor; |
| 44 | } |
| 45 | |
| 46 | #elif BITS_PER_LONG == 32 |
| 47 | |
| 48 | #ifndef div_u64_rem |
| 49 | static inline u64 div_u64_rem(u64 dividend, u32 divisor, u32 *remainder) |
| 50 | { |
| 51 | *remainder = do_div(dividend, divisor); |
| 52 | return dividend; |
| 53 | } |
| 54 | #endif |
| 55 | |
| 56 | #ifndef div_s64_rem |
| 57 | extern s64 div_s64_rem(s64 dividend, s32 divisor, s32 *remainder); |
| 58 | #endif |
| 59 | |
| 60 | #ifndef div64_u64 |
| 61 | extern u64 div64_u64(u64 dividend, u64 divisor); |
| 62 | #endif |
| 63 | |
| 64 | #ifndef div64_s64 |
| 65 | extern s64 div64_s64(s64 dividend, s64 divisor); |
| 66 | #endif |
| 67 | |
| 68 | #endif /* BITS_PER_LONG */ |
| 69 | |
| 70 | /** |
| 71 | * div_u64 - unsigned 64bit divide with 32bit divisor |
| 72 | * |
| 73 | * This is the most common 64bit divide and should be used if possible, |
| 74 | * as many 32bit archs can optimize this variant better than a full 64bit |
| 75 | * divide. |
| 76 | */ |
| 77 | #ifndef div_u64 |
| 78 | static inline u64 div_u64(u64 dividend, u32 divisor) |
| 79 | { |
| 80 | u32 remainder; |
| 81 | return div_u64_rem(dividend, divisor, &remainder); |
| 82 | } |
| 83 | #endif |
| 84 | |
| 85 | /** |
| 86 | * div_s64 - signed 64bit divide with 32bit divisor |
| 87 | */ |
| 88 | #ifndef div_s64 |
| 89 | static inline s64 div_s64(s64 dividend, s32 divisor) |
| 90 | { |
| 91 | s32 remainder; |
| 92 | return div_s64_rem(dividend, divisor, &remainder); |
| 93 | } |
| 94 | #endif |
| 95 | |
| 96 | u32 iter_div_u64_rem(u64 dividend, u32 divisor, u64 *remainder); |
| 97 | |
| 98 | static __always_inline u32 |
| 99 | __iter_div_u64_rem(u64 dividend, u32 divisor, u64 *remainder) |
| 100 | { |
| 101 | u32 ret = 0; |
| 102 | |
| 103 | while (dividend >= divisor) { |
| 104 | /* The following asm() prevents the compiler from |
| 105 | optimising this loop into a modulo operation. */ |
| 106 | asm("" : "+rm"(dividend)); |
| 107 | |
| 108 | dividend -= divisor; |
| 109 | ret++; |
| 110 | } |
| 111 | |
| 112 | *remainder = dividend; |
| 113 | |
| 114 | return ret; |
| 115 | } |
| 116 | |
| 117 | #endif /* _LINUX_MATH64_H */ |