LXR uboot/include/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
  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;           \
  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 */
  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
  49#endif /* _ASM_GENERIC_DIV64_H */
  50