arch/alpha/include/asm/word-at-a-time.h

   1 #ifndef _ASM_WORD_AT_A_TIME_H
   2 #define _ASM_WORD_AT_A_TIME_H
   3
   4 #include <asm/compiler.h>
   5
   6 /*
   7  * word-at-a-time interface for Alpha.
   8  */
   9
  10 /*
  11  * We do not use the word_at_a_time struct on Alpha, but it needs to be
  12  * implemented to humour the generic code.
  13  */
  14 struct word_at_a_time {
  15         const unsigned long unused;
  16 };
  17
  18 #define WORD_AT_A_TIME_CONSTANTS { 0 }
  19
  20 /* Return nonzero if val has a zero */
  21 static inline unsigned long has_zero(unsigned long val, unsigned long *bits, const struct word_at_a_time *c)
  22 {
  23         unsigned long zero_locations = __kernel_cmpbge(0, val);
  24         *bits = zero_locations;
  25         return zero_locations;
  26 }
  27
  28 static inline unsigned long prep_zero_mask(unsigned long val, unsigned long bits, const struct word_at_a_time *c)
  29 {
  30         return bits;
  31 }
  32
  33 #define create_zero_mask(bits) (bits)
  34
  35 static inline unsigned long find_zero(unsigned long bits)
  36 {
  37 #if defined(CONFIG_ALPHA_EV6) && defined(CONFIG_ALPHA_EV67)
  38         /* Simple if have CIX instructions */
  39         return __kernel_cttz(bits);
  40 #else
  41         unsigned long t1, t2, t3;
  42         /* Retain lowest set bit only */
  43         bits &= -bits;
  44         /* Binary search for lowest set bit */
  45         t1 = bits & 0xf0;
  46         t2 = bits & 0xcc;
  47         t3 = bits & 0xaa;
  48         if (t1) t1 = 4;
  49         if (t2) t2 = 2;
  50         if (t3) t3 = 1;
  51         return t1 + t2 + t3;
  52 #endif
  53 }
  54
  55 #define zero_bytemask(mask) ((2ul << (find_zero(mask) * 8)) - 1)
  56
  57 #endif /* _ASM_WORD_AT_A_TIME_H */