include/linux/bitops.h

   1 #ifndef _LINUX_BITOPS_H
   2 #define _LINUX_BITOPS_H
   3 #include <asm/types.h>
   4
   5 #ifdef  __KERNEL__
   6 #define BIT(nr)                 (1UL << (nr))
   7 #define BIT_MASK(nr)            (1UL << ((nr) % BITS_PER_LONG))
   8 #define BIT_WORD(nr)            ((nr) / BITS_PER_LONG)
   9 #define BITS_TO_TYPE(nr, t)     (((nr)+(t)-1)/(t))
  10 #define BITS_TO_LONGS(nr)       BITS_TO_TYPE(nr, BITS_PER_LONG)
  11 #define BITS_PER_BYTE           8
  12 #endif
  13
  14 /*
  15  * Include this here because some architectures need generic_ffs/fls in
  16  * scope
  17  */
  18 #include <asm/bitops.h>
  19
  20 #define for_each_bit(bit, addr, size) \
  21         for ((bit) = find_first_bit((addr), (size)); \
  22              (bit) < (size); \
  23              (bit) = find_next_bit((addr), (size), (bit) + 1))
  24
  25
  26 static __inline__ int get_bitmask_order(unsigned int count)
  27 {
  28         int order;
  29
  30         order = fls(count);
  31         return order;   /* We could be slightly more clever with -1 here... */
  32 }
  33
  34 static __inline__ int get_count_order(unsigned int count)
  35 {
  36         int order;
  37
  38         order = fls(count) - 1;
  39         if (count & (count - 1))
  40                 order++;
  41         return order;
  42 }
  43
  44 static inline unsigned long hweight_long(unsigned long w)
  45 {
  46         return sizeof(w) == 4 ? hweight32(w) : hweight64(w);
  47 }
  48
  49 /**
  50  * rol32 - rotate a 32-bit value left
  51  * @word: value to rotate
  52  * @shift: bits to roll
  53  */
  54 static inline __u32 rol32(__u32 word, unsigned int shift)
  55 {
  56         return (word << shift) | (word >> (32 - shift));
  57 }
  58
  59 /**
  60  * ror32 - rotate a 32-bit value right
  61  * @word: value to rotate
  62  * @shift: bits to roll
  63  */
  64 static inline __u32 ror32(__u32 word, unsigned int shift)
  65 {
  66         return (word >> shift) | (word << (32 - shift));
  67 }
  68
  69 static inline unsigned fls_long(unsigned long l)
  70 {
  71         if (sizeof(l) == 4)
  72                 return fls(l);
  73         return fls64(l);
  74 }
  75
  76 #endif