blob: d83314435d860d59ffb9d5a14284d70a3c3a4453
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 | |
22 | extern uint32_t __div64_32(uint64_t *dividend, uint32_t divisor); |
23 | |
24 | /* The unnecessary pointer compare is there |
25 | * to check for type safety (n must be 64bit) |
26 | */ |
27 | # define do_div(n,base) ({ \ |
28 | uint32_t __base = (base); \ |
29 | uint32_t __rem; \ |
30 | (void)(((typeof((n)) *)0) == ((uint64_t *)0)); \ |
31 | if (((n) >> 32) == 0) { \ |
32 | __rem = (uint32_t)(n) % __base; \ |
33 | (n) = (uint32_t)(n) / __base; \ |
34 | } else \ |
35 | __rem = __div64_32(&(n), __base); \ |
36 | __rem; \ |
37 | }) |
38 | |
39 | /* Wrapper for do_div(). Doesn't modify dividend and returns |
40 | * the result, not reminder. |
41 | */ |
42 | static inline uint64_t lldiv(uint64_t dividend, uint32_t divisor) |
43 | { |
44 | uint64_t __res = dividend; |
45 | do_div(__res, divisor); |
46 | return(__res); |
47 | } |
48 | |
49 | #endif /* _ASM_GENERIC_DIV64_H */ |
50 |