1 /*
2  * Copyright (C) 2012 Regents of the University of California
3  *
4  *   This program is free software; you can redistribute it and/or
5  *   modify it under the terms of the GNU General Public License
6  *   as published by the Free Software Foundation, version 2.
7  *
8  *   This program is distributed in the hope that it will be useful,
9  *   but WITHOUT ANY WARRANTY; without even the implied warranty of
10  *   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
11  *   GNU General Public License for more details.
12  * Derived from arch/x86/include/asm/word-at-a-time.h
13  */
14 
15 #ifndef _ASM_RISCV_WORD_AT_A_TIME_H
16 #define _ASM_RISCV_WORD_AT_A_TIME_H
17 
18 
19 #include <linux/kernel.h>
20 
21 struct word_at_a_time {
22 	const unsigned long one_bits, high_bits;
23 };
24 
25 #define WORD_AT_A_TIME_CONSTANTS { REPEAT_BYTE(0x01), REPEAT_BYTE(0x80) }
26 
27 static inline unsigned long has_zero(unsigned long val,
28 	unsigned long *bits, const struct word_at_a_time *c)
29 {
30 	unsigned long mask = ((val - c->one_bits) & ~val) & c->high_bits;
31 	*bits = mask;
32 	return mask;
33 }
34 
35 static inline unsigned long prep_zero_mask(unsigned long val,
36 	unsigned long bits, const struct word_at_a_time *c)
37 {
38 	return bits;
39 }
40 
41 static inline unsigned long create_zero_mask(unsigned long bits)
42 {
43 	bits = (bits - 1) & ~bits;
44 	return bits >> 7;
45 }
46 
47 static inline unsigned long find_zero(unsigned long mask)
48 {
49 	return fls64(mask) >> 3;
50 }
51 
52 /* The mask we created is directly usable as a bytemask */
53 #define zero_bytemask(mask) (mask)
54 
55 #endif /* _ASM_RISCV_WORD_AT_A_TIME_H */
56