Viewing file:  word-at-a-time.h (1.34 KB) -rw-r--r--
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/* SPDX-License-Identifier: GPL-2.0 */
#ifndef _ASM_WORD_AT_A_TIME_H
#define _ASM_WORD_AT_A_TIME_H
#include <asm/compiler.h>
/*
* word-at-a-time interface for Alpha.
*/
/*
* We do not use the word_at_a_time struct on Alpha, but it needs to be
* implemented to humour the generic code.
*/
struct word_at_a_time {
const unsigned long unused;
};
#define WORD_AT_A_TIME_CONSTANTS { 0 }
/* Return nonzero if val has a zero */
static inline unsigned long has_zero(unsigned long val, unsigned long *bits, const struct word_at_a_time *c)
{
unsigned long zero_locations = __kernel_cmpbge(0, val);
*bits = zero_locations;
return zero_locations;
}
static inline unsigned long prep_zero_mask(unsigned long val, unsigned long bits, const struct word_at_a_time *c)
{
return bits;
}
#define create_zero_mask(bits) (bits)
static inline unsigned long find_zero(unsigned long bits)
{
#if defined(CONFIG_ALPHA_EV6) && defined(CONFIG_ALPHA_EV67)
/* Simple if have CIX instructions */
return __kernel_cttz(bits);
#else
unsigned long t1, t2, t3;
/* Retain lowest set bit only */
bits &= -bits;
/* Binary search for lowest set bit */
t1 = bits & 0xf0;
t2 = bits & 0xcc;
t3 = bits & 0xaa;
if (t1) t1 = 4;
if (t2) t2 = 2;
if (t3) t3 = 1;
return t1 + t2 + t3;
#endif
}
#define zero_bytemask(mask) ((2ul << (find_zero(mask) * 8)) - 1)
#endif /* _ASM_WORD_AT_A_TIME_H */
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