include/linux/math64.h

   1 #ifndef _LINUX_MATH64_H
   2 #define _LINUX_MATH64_H
   3
   4 #include <linux/types.h>
   5
   6 #if BITS_PER_LONG == 64
   7
   8 /**
   9  * div_u64_rem - unsigned 64bit divide with 32bit divisor with remainder
  10  *
  11  * This is commonly provided by 32bit archs to provide an optimized 64bit
  12  * divide.
  13  */
  14 static inline u64 div_u64_rem(u64 dividend, u32 divisor, u32 *remainder)
  15 {
  16         *remainder = dividend % divisor;
  17         return dividend / divisor;
  18 }
  19
  20 /**
  21  * div_s64_rem - signed 64bit divide with 32bit divisor with remainder
  22  */
  23 static inline s64 div_s64_rem(s64 dividend, s32 divisor, s32 *remainder)
  24 {
  25         *remainder = dividend % divisor;
  26         return dividend / divisor;
  27 }
  28
  29 /**
  30  * div64_u64 - unsigned 64bit divide with 64bit divisor
  31  */
  32 static inline u64 div64_u64(u64 dividend, u64 divisor)
  33 {
  34         return dividend / divisor;
  35 }
  36
  37 #elif BITS_PER_LONG == 32
  38
  39 #ifndef div_u64_rem
  40 static inline u64 div_u64_rem(u64 dividend, u32 divisor, u32 *remainder)
  41 {
  42         *remainder = do_div(dividend, divisor);
  43         return dividend;
  44 }
  45 #endif
  46
  47 #ifndef div_s64_rem
  48 extern s64 div_s64_rem(s64 dividend, s32 divisor, s32 *remainder);
  49 #endif
  50
  51 #ifndef div64_u64
  52 extern u64 div64_u64(u64 dividend, u64 divisor);
  53 #endif
  54
  55 #endif /* BITS_PER_LONG */
  56
  57 /**
  58  * div_u64 - unsigned 64bit divide with 32bit divisor
  59  *
  60  * This is the most common 64bit divide and should be used if possible,
  61  * as many 32bit archs can optimize this variant better than a full 64bit
  62  * divide.
  63  */
  64 #ifndef div_u64
  65 static inline u64 div_u64(u64 dividend, u32 divisor)
  66 {
  67         u32 remainder;
  68         return div_u64_rem(dividend, divisor, &remainder);
  69 }
  70 #endif
  71
  72 /**
  73  * div_s64 - signed 64bit divide with 32bit divisor
  74  */
  75 #ifndef div_s64
  76 static inline s64 div_s64(s64 dividend, s32 divisor)
  77 {
  78         s32 remainder;
  79         return div_s64_rem(dividend, divisor, &remainder);
  80 }
  81 #endif
  82
  83 u32 iter_div_u64_rem(u64 dividend, u32 divisor, u64 *remainder);
  84
  85 #endif /* _LINUX_MATH64_H */