include/linux/bitops.h

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