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 */
18static 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 */
27static 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 */
36static 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 */
45static 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 */
53static 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
64static 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
72extern s64 div_s64_rem(s64 dividend, s32 divisor, s32 *remainder);
73#endif
74
75#ifndef div64_u64_rem
76extern u64 div64_u64_rem(u64 dividend, u64 divisor, u64 *remainder);
77#endif
78
79#ifndef div64_u64
80extern u64 div64_u64(u64 dividend, u64 divisor);
81#endif
82
83#ifndef div64_s64
84extern 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
97static 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
108static inline s64 div_s64(s64 dividend, s32 divisor)
109{
110	s32 remainder;
111	return div_s64_rem(dividend, divisor, &remainder);
112}
113#endif
114
115u32 iter_div_u64_rem(u64 dividend, u32 divisor, u64 *remainder);
116
117static __always_inline u32
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#if defined(CONFIG_ARCH_SUPPORTS_INT128) && defined(__SIZEOF_INT128__)
137
138#ifndef mul_u64_u32_shr
139static inline u64 mul_u64_u32_shr(u64 a, u32 mul, unsigned int shift)
140{
141	return (u64)(((unsigned __int128)a * mul) >> shift);
142}
143#endif /* mul_u64_u32_shr */
144
145#else
146
147#ifndef mul_u64_u32_shr
148static inline u64 mul_u64_u32_shr(u64 a, u32 mul, unsigned int shift)
149{
150	u32 ah, al;
151	u64 ret;
152
153	al = a;
154	ah = a >> 32;
155
156	ret = ((u64)al * mul) >> shift;
157	if (ah)
158		ret += ((u64)ah * mul) << (32 - shift);
159
160	return ret;
161}
162#endif /* mul_u64_u32_shr */
163
164#endif
165
166#endif /* _LINUX_MATH64_H */
167