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 static __inline__ int get_bitmask_order(unsigned int count)
  12 {
  13         int order;
  14
  15         order = fls(count);
  16         return order;   /* We could be slightly more clever with -1 here... */
  17 }
  18
  19 static __inline__ int get_count_order(unsigned int count)
  20 {
  21         int order;
  22
  23         order = fls(count) - 1;
  24         if (count & (count - 1))
  25                 order++;
  26         return order;
  27 }
  28
  29 static inline unsigned long hweight_long(unsigned long w)
  30 {
  31         return sizeof(w) == 4 ? hweight32(w) : hweight64(w);
  32 }
  33
  34 /**
  35  * rol32 - rotate a 32-bit value left
  36  * @word: value to rotate
  37  * @shift: bits to roll
  38  */
  39 static inline __u32 rol32(__u32 word, unsigned int shift)
  40 {
  41         return (word << shift) | (word >> (32 - shift));
  42 }
  43
  44 /**
  45  * ror32 - rotate a 32-bit value right
  46  * @word: value to rotate
  47  * @shift: bits to roll
  48  */
  49 static inline __u32 ror32(__u32 word, unsigned int shift)
  50 {
  51         return (word >> shift) | (word << (32 - shift));
  52 }
  53
  54 static inline unsigned fls_long(unsigned long l)
  55 {
  56         if (sizeof(l) == 4)
  57                 return fls(l);
  58         return fls64(l);
  59 }
  60
  61 #endif