asm-generic/gpio.h: add some forward decls of the device struct
[linux-2.6.git] / include / asm-generic / div64.h
1 #ifndef _ASM_GENERIC_DIV64_H
2 #define _ASM_GENERIC_DIV64_H
3 /*
4  * Copyright (C) 2003 Bernardo Innocenti <bernie@develer.com>
5  * Based on former asm-ppc/div64.h and asm-m68knommu/div64.h
6  *
7  * The semantics of do_div() are:
8  *
9  * uint32_t do_div(uint64_t *n, uint32_t base)
10  * {
11  *      uint32_t remainder = *n % base;
12  *      *n = *n / base;
13  *      return remainder;
14  * }
15  *
16  * NOTE: macro parameter n is evaluated multiple times,
17  *       beware of side effects!
18  */
19
20 #include <linux/types.h>
21 #include <linux/compiler.h>
22
23 #if BITS_PER_LONG == 64
24
25 # define do_div(n,base) ({                                      \
26         uint32_t __base = (base);                               \
27         uint32_t __rem;                                         \
28         __rem = ((uint64_t)(n)) % __base;                       \
29         (n) = ((uint64_t)(n)) / __base;                         \
30         __rem;                                                  \
31  })
32
33 #elif BITS_PER_LONG == 32
34
35 extern uint32_t __div64_32(uint64_t *dividend, uint32_t divisor);
36
37 /* The unnecessary pointer compare is there
38  * to check for type safety (n must be 64bit)
39  */
40 # define do_div(n,base) ({                              \
41         uint32_t __base = (base);                       \
42         uint32_t __rem;                                 \
43         (void)(((typeof((n)) *)0) == ((uint64_t *)0));  \
44         if (likely(((n) >> 32) == 0)) {                 \
45                 __rem = (uint32_t)(n) % __base;         \
46                 (n) = (uint32_t)(n) / __base;           \
47         } else                                          \
48                 __rem = __div64_32(&(n), __base);       \
49         __rem;                                          \
50  })
51
52 #else /* BITS_PER_LONG == ?? */
53
54 # error do_div() does not yet support the C64
55
56 #endif /* BITS_PER_LONG */
57
58 #endif /* _ASM_GENERIC_DIV64_H */