async: make sure independent async domains can't accidentally entangle
[linux-2.6/mini2440.git] / include / linux / math64.h
blobc87f1528703a68c2dd024d612a203ae4517b5cea
1 #ifndef _LINUX_MATH64_H
2 #define _LINUX_MATH64_H
4 #include <linux/types.h>
5 #include <asm/div64.h>
7 #if BITS_PER_LONG == 64
9 /**
10 * div_u64_rem - unsigned 64bit divide with 32bit divisor with remainder
12 * This is commonly provided by 32bit archs to provide an optimized 64bit
13 * divide.
15 static inline u64 div_u64_rem(u64 dividend, u32 divisor, u32 *remainder)
17 *remainder = dividend % divisor;
18 return dividend / divisor;
21 /**
22 * div_s64_rem - signed 64bit divide with 32bit divisor with remainder
24 static inline s64 div_s64_rem(s64 dividend, s32 divisor, s32 *remainder)
26 *remainder = dividend % divisor;
27 return dividend / divisor;
30 /**
31 * div64_u64 - unsigned 64bit divide with 64bit divisor
33 static inline u64 div64_u64(u64 dividend, u64 divisor)
35 return dividend / divisor;
38 #elif BITS_PER_LONG == 32
40 #ifndef div_u64_rem
41 static inline u64 div_u64_rem(u64 dividend, u32 divisor, u32 *remainder)
43 *remainder = do_div(dividend, divisor);
44 return dividend;
46 #endif
48 #ifndef div_s64_rem
49 extern s64 div_s64_rem(s64 dividend, s32 divisor, s32 *remainder);
50 #endif
52 #ifndef div64_u64
53 extern u64 div64_u64(u64 dividend, u64 divisor);
54 #endif
56 #endif /* BITS_PER_LONG */
58 /**
59 * div_u64 - unsigned 64bit divide with 32bit divisor
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.
65 #ifndef div_u64
66 static inline u64 div_u64(u64 dividend, u32 divisor)
68 u32 remainder;
69 return div_u64_rem(dividend, divisor, &remainder);
71 #endif
73 /**
74 * div_s64 - signed 64bit divide with 32bit divisor
76 #ifndef div_s64
77 static inline s64 div_s64(s64 dividend, s32 divisor)
79 s32 remainder;
80 return div_s64_rem(dividend, divisor, &remainder);
82 #endif
84 u32 iter_div_u64_rem(u64 dividend, u32 divisor, u64 *remainder);
86 static __always_inline u32
87 __iter_div_u64_rem(u64 dividend, u32 divisor, u64 *remainder)
89 u32 ret = 0;
91 while (dividend >= divisor) {
92 /* The following asm() prevents the compiler from
93 optimising this loop into a modulo operation. */
94 asm("" : "+rm"(dividend));
96 dividend -= divisor;
97 ret++;
100 *remainder = dividend;
102 return ret;
105 #endif /* _LINUX_MATH64_H */