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Linux kernel mirror (for testing)
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linux
1/*
2 * include/asm-xtensa/bitops.h
3 *
4 * Atomic operations that C can't guarantee us.Useful for resource counting etc.
5 *
6 * This file is subject to the terms and conditions of the GNU General Public
7 * License. See the file "COPYING" in the main directory of this archive
8 * for more details.
9 *
10 * Copyright (C) 2001 - 2007 Tensilica Inc.
11 */
12
13#ifndef _XTENSA_BITOPS_H
14#define _XTENSA_BITOPS_H
15
16#ifdef __KERNEL__
17
18#ifndef _LINUX_BITOPS_H
19#error only <linux/bitops.h> can be included directly
20#endif
21
22#include <asm/processor.h>
23#include <asm/byteorder.h>
24
25#ifdef CONFIG_SMP
26# error SMP not supported on this architecture
27#endif
28
29#define smp_mb__before_clear_bit() barrier()
30#define smp_mb__after_clear_bit() barrier()
31
32#include <asm-generic/bitops/atomic.h>
33#include <asm-generic/bitops/non-atomic.h>
34
35#if XCHAL_HAVE_NSA
36
37static inline unsigned long __cntlz (unsigned long x)
38{
39 int lz;
40 asm ("nsau %0, %1" : "=r" (lz) : "r" (x));
41 return lz;
42}
43
44/*
45 * ffz: Find first zero in word. Undefined if no zero exists.
46 * bit 0 is the LSB of addr; bit 32 is the LSB of (addr+1).
47 */
48
49static inline int ffz(unsigned long x)
50{
51 return 31 - __cntlz(~x & -~x);
52}
53
54/*
55 * __ffs: Find first bit set in word. Return 0 for bit 0
56 */
57
58static inline int __ffs(unsigned long x)
59{
60 return 31 - __cntlz(x & -x);
61}
62
63/*
64 * ffs: Find first bit set in word. This is defined the same way as
65 * the libc and compiler builtin ffs routines, therefore
66 * differs in spirit from the above ffz (man ffs).
67 */
68
69static inline int ffs(unsigned long x)
70{
71 return 32 - __cntlz(x & -x);
72}
73
74/*
75 * fls: Find last (most-significant) bit set in word.
76 * Note fls(0) = 0, fls(1) = 1, fls(0x80000000) = 32.
77 */
78
79static inline int fls (unsigned int x)
80{
81 return 32 - __cntlz(x);
82}
83
84/**
85 * __fls - find last (most-significant) set bit in a long word
86 * @word: the word to search
87 *
88 * Undefined if no set bit exists, so code should check against 0 first.
89 */
90static inline unsigned long __fls(unsigned long word)
91{
92 return 31 - __cntlz(word);
93}
94#else
95
96/* Use the generic implementation if we don't have the nsa/nsau instructions. */
97
98# include <asm-generic/bitops/ffs.h>
99# include <asm-generic/bitops/__ffs.h>
100# include <asm-generic/bitops/ffz.h>
101# include <asm-generic/bitops/fls.h>
102# include <asm-generic/bitops/__fls.h>
103
104#endif
105
106#include <asm-generic/bitops/fls64.h>
107#include <asm-generic/bitops/find.h>
108#include <asm-generic/bitops/le.h>
109
110#include <asm-generic/bitops/ext2-atomic-setbit.h>
111
112#include <asm-generic/bitops/hweight.h>
113#include <asm-generic/bitops/lock.h>
114#include <asm-generic/bitops/sched.h>
115
116#endif /* __KERNEL__ */
117
118#endif /* _XTENSA_BITOPS_H */