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b.liue9582032025-04-17 19:18:16 +08001/* SPDX-License-Identifier: GPL-2.0-only */
2/*
3 * Copyright (C) 2012 Regents of the University of California
4 *
5 * Derived from arch/x86/include/asm/word-at-a-time.h
6 */
7
8#ifndef _ASM_RISCV_WORD_AT_A_TIME_H
9#define _ASM_RISCV_WORD_AT_A_TIME_H
10
11
12#include <linux/kernel.h>
13
14struct word_at_a_time {
15 const unsigned long one_bits, high_bits;
16};
17
18#define WORD_AT_A_TIME_CONSTANTS { REPEAT_BYTE(0x01), REPEAT_BYTE(0x80) }
19
20static inline unsigned long has_zero(unsigned long val,
21 unsigned long *bits, const struct word_at_a_time *c)
22{
23 unsigned long mask = ((val - c->one_bits) & ~val) & c->high_bits;
24 *bits = mask;
25 return mask;
26}
27
28static inline unsigned long prep_zero_mask(unsigned long val,
29 unsigned long bits, const struct word_at_a_time *c)
30{
31 return bits;
32}
33
34static inline unsigned long create_zero_mask(unsigned long bits)
35{
36 bits = (bits - 1) & ~bits;
37 return bits >> 7;
38}
39
40static inline unsigned long find_zero(unsigned long mask)
41{
42 return fls64(mask) >> 3;
43}
44
45/* The mask we created is directly usable as a bytemask */
46#define zero_bytemask(mask) (mask)
47
48#endif /* _ASM_RISCV_WORD_AT_A_TIME_H */