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2418f4f2 RZ |
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 | ||
6f6d6a1a RZ |
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 | ||
2418f4f2 RZ |
38 | #elif BITS_PER_LONG == 32 |
39 | ||
40 | #ifndef div_u64_rem | |
41 | static inline u64 div_u64_rem(u64 dividend, u32 divisor, u32 *remainder) | |
42 | { | |
43 | *remainder = do_div(dividend, divisor); | |
44 | return dividend; | |
45 | } | |
46 | #endif | |
47 | ||
48 | #ifndef div_s64_rem | |
49 | extern s64 div_s64_rem(s64 dividend, s32 divisor, s32 *remainder); | |
50 | #endif | |
51 | ||
6f6d6a1a RZ |
52 | #ifndef div64_u64 |
53 | extern u64 div64_u64(u64 dividend, u64 divisor); | |
54 | #endif | |
55 | ||
2418f4f2 RZ |
56 | #endif /* BITS_PER_LONG */ |
57 | ||
58 | /** | |
59 | * div_u64 - unsigned 64bit divide with 32bit divisor | |
60 | * | |
61 | * This is the most common 64bit divide and should be used if possible, | |
62 | * as many 32bit archs can optimize this variant better than a full 64bit | |
63 | * divide. | |
64 | */ | |
65 | #ifndef div_u64 | |
66 | static inline u64 div_u64(u64 dividend, u32 divisor) | |
67 | { | |
68 | u32 remainder; | |
69 | return div_u64_rem(dividend, divisor, &remainder); | |
70 | } | |
71 | #endif | |
72 | ||
73 | /** | |
74 | * div_s64 - signed 64bit divide with 32bit divisor | |
75 | */ | |
76 | #ifndef div_s64 | |
77 | static inline s64 div_s64(s64 dividend, s32 divisor) | |
78 | { | |
79 | s32 remainder; | |
80 | return div_s64_rem(dividend, divisor, &remainder); | |
81 | } | |
82 | #endif | |
83 | ||
f595ec96 JF |
84 | u32 iter_div_u64_rem(u64 dividend, u32 divisor, u64 *remainder); |
85 | ||
d5e181f7 JF |
86 | static __always_inline u32 |
87 | __iter_div_u64_rem(u64 dividend, u32 divisor, u64 *remainder) | |
88 | { | |
89 | u32 ret = 0; | |
90 | ||
91 | while (dividend >= divisor) { | |
92 | /* The following asm() prevents the compiler from | |
93 | optimising this loop into a modulo operation. */ | |
94 | asm("" : "+rm"(dividend)); | |
95 | ||
96 | dividend -= divisor; | |
97 | ret++; | |
98 | } | |
99 | ||
100 | *remainder = dividend; | |
101 | ||
102 | return ret; | |
103 | } | |
104 | ||
2418f4f2 | 105 | #endif /* _LINUX_MATH64_H */ |