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