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 #define div64_long(x, y) div64_s64((x), (y))
10 #define div64_ul(x, y) div64_u64((x), (y))
11
12 /**
13 * div_u64_rem - unsigned 64bit divide with 32bit divisor with remainder
14 *
15 * This is commonly provided by 32bit archs to provide an optimized 64bit
16 * divide.
17 */
div_u64_rem(u64 dividend,u32 divisor,u32 * remainder)18 static inline u64 div_u64_rem(u64 dividend, u32 divisor, u32 *remainder)
19 {
20 *remainder = dividend % divisor;
21 return dividend / divisor;
22 }
23
24 /**
25 * div_s64_rem - signed 64bit divide with 32bit divisor with remainder
26 */
div_s64_rem(s64 dividend,s32 divisor,s32 * remainder)27 static inline s64 div_s64_rem(s64 dividend, s32 divisor, s32 *remainder)
28 {
29 *remainder = dividend % divisor;
30 return dividend / divisor;
31 }
32
33 /**
34 * div64_u64_rem - unsigned 64bit divide with 64bit divisor and remainder
35 */
div64_u64_rem(u64 dividend,u64 divisor,u64 * remainder)36 static inline u64 div64_u64_rem(u64 dividend, u64 divisor, u64 *remainder)
37 {
38 *remainder = dividend % divisor;
39 return dividend / divisor;
40 }
41
42 /**
43 * div64_u64 - unsigned 64bit divide with 64bit divisor
44 */
div64_u64(u64 dividend,u64 divisor)45 static inline u64 div64_u64(u64 dividend, u64 divisor)
46 {
47 return dividend / divisor;
48 }
49
50 /**
51 * div64_s64 - signed 64bit divide with 64bit divisor
52 */
div64_s64(s64 dividend,s64 divisor)53 static inline s64 div64_s64(s64 dividend, s64 divisor)
54 {
55 return dividend / divisor;
56 }
57
58 #elif BITS_PER_LONG == 32
59
60 #define div64_long(x, y) div_s64((x), (y))
61 #define div64_ul(x, y) div_u64((x), (y))
62
63 #ifndef div_u64_rem
div_u64_rem(u64 dividend,u32 divisor,u32 * remainder)64 static inline u64 div_u64_rem(u64 dividend, u32 divisor, u32 *remainder)
65 {
66 *remainder = do_div(dividend, divisor);
67 return dividend;
68 }
69 #endif
70
71 #ifndef div_s64_rem
72 extern s64 div_s64_rem(s64 dividend, s32 divisor, s32 *remainder);
73 #endif
74
75 #ifndef div64_u64_rem
76 extern u64 div64_u64_rem(u64 dividend, u64 divisor, u64 *remainder);
77 #endif
78
79 #ifndef div64_u64
80 extern u64 div64_u64(u64 dividend, u64 divisor);
81 #endif
82
83 #ifndef div64_s64
84 extern s64 div64_s64(s64 dividend, s64 divisor);
85 #endif
86
87 #endif /* BITS_PER_LONG */
88
89 /**
90 * div_u64 - unsigned 64bit divide with 32bit divisor
91 *
92 * This is the most common 64bit divide and should be used if possible,
93 * as many 32bit archs can optimize this variant better than a full 64bit
94 * divide.
95 */
96 #ifndef div_u64
div_u64(u64 dividend,u32 divisor)97 static inline u64 div_u64(u64 dividend, u32 divisor)
98 {
99 u32 remainder;
100 return div_u64_rem(dividend, divisor, &remainder);
101 }
102 #endif
103
104 /**
105 * div_s64 - signed 64bit divide with 32bit divisor
106 */
107 #ifndef div_s64
div_s64(s64 dividend,s32 divisor)108 static inline s64 div_s64(s64 dividend, s32 divisor)
109 {
110 s32 remainder;
111 return div_s64_rem(dividend, divisor, &remainder);
112 }
113 #endif
114
115 u32 iter_div_u64_rem(u64 dividend, u32 divisor, u64 *remainder);
116
117 static __always_inline u32
__iter_div_u64_rem(u64 dividend,u32 divisor,u64 * remainder)118 __iter_div_u64_rem(u64 dividend, u32 divisor, u64 *remainder)
119 {
120 u32 ret = 0;
121
122 while (dividend >= divisor) {
123 /* The following asm() prevents the compiler from
124 optimising this loop into a modulo operation. */
125 asm("" : "+rm"(dividend));
126
127 dividend -= divisor;
128 ret++;
129 }
130
131 *remainder = dividend;
132
133 return ret;
134 }
135
136 #endif /* _LINUX_MATH64_H */
137