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

   1/* SPDX-License-Identifier: GPL-2.0 */
   2#ifndef _ASM_WORD_AT_A_TIME_H
   3#define _ASM_WORD_AT_A_TIME_H
   4
   5#include <asm/compiler.h>
   6
   7/*
   8 * word-at-a-time interface for Alpha.
   9 */
  10
  11/*
  12 * We do not use the word_at_a_time struct on Alpha, but it needs to be
  13 * implemented to humour the generic code.
  14 */
  15struct word_at_a_time {
  16        const unsigned long unused;
  17};
  18
  19#define WORD_AT_A_TIME_CONSTANTS { 0 }
  20
  21/* Return nonzero if val has a zero */
  22static inline unsigned long has_zero(unsigned long val, unsigned long *bits, const struct word_at_a_time *c)
  23{
  24        unsigned long zero_locations = __kernel_cmpbge(0, val);
  25        *bits = zero_locations;
  26        return zero_locations;
  27}
  28
  29static inline unsigned long prep_zero_mask(unsigned long val, unsigned long bits, const struct word_at_a_time *c)
  30{
  31        return bits;
  32}
  33
  34#define create_zero_mask(bits) (bits)
  35
  36static inline unsigned long find_zero(unsigned long bits)
  37{
  38#if defined(CONFIG_ALPHA_EV6) && defined(CONFIG_ALPHA_EV67)
  39        /* Simple if have CIX instructions */
  40        return __kernel_cttz(bits);
  41#else
  42        unsigned long t1, t2, t3;
  43        /* Retain lowest set bit only */
  44        bits &= -bits;
  45        /* Binary search for lowest set bit */
  46        t1 = bits & 0xf0;
  47        t2 = bits & 0xcc;
  48        t3 = bits & 0xaa;
  49        if (t1) t1 = 4;
  50        if (t2) t2 = 2;
  51        if (t3) t3 = 1;
  52        return t1 + t2 + t3;
  53#endif
  54}
  55
  56#define zero_bytemask(mask) ((2ul << (find_zero(mask) * 8)) - 1)
  57
  58#endif /* _ASM_WORD_AT_A_TIME_H */
  59