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Wolfgang Denk7b64fef2006-10-24 14:21:16 +02001#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 * {
Wolfgang Denk53677ef2008-05-20 16:00:29 +020011 * uint32_t remainder = *n % base;
12 * *n = *n / base;
13 * return remainder;
Wolfgang Denk7b64fef2006-10-24 14:21:16 +020014 * }
15 *
16 * NOTE: macro parameter n is evaluated multiple times,
17 * beware of side effects!
18 */
19
20#include <linux/types.h>
21
22extern 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; \
Wolfgang Denk53677ef2008-05-20 16:00:29 +020034 } else \
Wolfgang Denk7b64fef2006-10-24 14:21:16 +020035 __rem = __div64_32(&(n), __base); \
36 __rem; \
37 })
38
Sergei Poselenov3feb6472008-11-04 13:51:18 +010039/* Wrapper for do_div(). Doesn't modify dividend and returns
40 * the result, not reminder.
41 */
42static 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
Wolfgang Denk7b64fef2006-10-24 14:21:16 +020049#endif /* _ASM_GENERIC_DIV64_H */