1#ifndef _ASM_WORD_AT_A_TIME_H
2#define _ASM_WORD_AT_A_TIME_H
3
4/*
5 * This says "generic", but it's actually big-endian only.
6 * Little-endian can use more efficient versions of these
7 * interfaces, see for example
8 *	 arch/x86/include/asm/word-at-a-time.h
9 * for those.
10 */
11
12#include <linux/kernel.h>
13
14struct word_at_a_time {
15	const unsigned long high_bits, low_bits;
16};
17
18#define WORD_AT_A_TIME_CONSTANTS { REPEAT_BYTE(0xfe) + 1, REPEAT_BYTE(0x7f) }
19
20/* Bit set in the bytes that have a zero */
21static inline long prep_zero_mask(unsigned long val, unsigned long rhs, const struct word_at_a_time *c)
22{
23	unsigned long mask = (val & c->low_bits) + c->low_bits;
24	return ~(mask | rhs);
25}
26
27#define create_zero_mask(mask) (mask)
28
29static inline long find_zero(unsigned long mask)
30{
31	long byte = 0;
32#ifdef CONFIG_64BIT
33	if (mask >> 32)
34		mask >>= 32;
35	else
36		byte = 4;
37#endif
38	if (mask >> 16)
39		mask >>= 16;
40	else
41		byte += 2;
42	return (mask >> 8) ? byte : byte + 1;
43}
44
45static inline bool has_zero(unsigned long val, unsigned long *data, const struct word_at_a_time *c)
46{
47	unsigned long rhs = val | c->low_bits;
48	*data = rhs;
49	return (val + c->high_bits) & ~rhs;
50}
51
52#ifndef zero_bytemask
53#define zero_bytemask(mask) (~1ul << __fls(mask))
54#endif
55
56#endif /* _ASM_WORD_AT_A_TIME_H */
57