LXR uboot/include/asm-m68k/bitops.h

   1/*
   2 * bitops.h: Bit string operations on the m68k
   3 */
   4
   5#ifndef _M68K_BITOPS_H
   6#define _M68K_BITOPS_H
   7
   8#include <linux/config.h>
   9#include <asm/byteorder.h>
  10
  11extern void set_bit(int nr, volatile void *addr);
  12extern void clear_bit(int nr, volatile void *addr);
  13extern void change_bit(int nr, volatile void *addr);
  14extern int test_and_set_bit(int nr, volatile void *addr);
  15extern int test_and_clear_bit(int nr, volatile void *addr);
  16extern int test_and_change_bit(int nr, volatile void *addr);
  17
  18#ifdef __KERNEL__
  19
  20/*
  21 * ffs: find first bit set. This is defined the same way as
  22 * the libc and compiler builtin ffs routines, therefore
  23 * differs in spirit from the above ffz (man ffs).
  24 */
  25extern __inline__ int ffs(int x)
  26{
  27        int r = 1;
  28
  29        if (!x)
  30                return 0;
  31        if (!(x & 0xffff)) {
  32                x >>= 16;
  33                r += 16;
  34        }
  35        if (!(x & 0xff)) {
  36                x >>= 8;
  37                r += 8;
  38        }
  39        if (!(x & 0xf)) {
  40                x >>= 4;
  41                r += 4;
  42        }
  43        if (!(x & 3)) {
  44                x >>= 2;
  45                r += 2;
  46        }
  47        if (!(x & 1)) {
  48                x >>= 1;
  49                r += 1;
  50        }
  51        return r;
  52}
  53#define __ffs(x) (ffs(x) - 1)
  54#define PLATFORM_FFS
  55
  56#endif /* __KERNEL__ */
  57
  58#endif /* _M68K_BITOPS_H */
  59