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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#include <asm/system.h>
25
26#ifdef CONFIG_SMP
27# error SMP not supported on this architecture
28#endif
29
30#define smp_mb__before_clear_bit() barrier()
31#define smp_mb__after_clear_bit() barrier()
32
33#include <asm-generic/bitops/atomic.h>
34#include <asm-generic/bitops/non-atomic.h>
35
36#if XCHAL_HAVE_NSA
37
38static inline unsigned long __cntlz (unsigned long x)
39{
40 int lz;
41 asm ("nsau %0, %1" : "=r" (lz) : "r" (x));
42 return lz;
43}
44
45/*
46 * ffz: Find first zero in word. Undefined if no zero exists.
47 * bit 0 is the LSB of addr; bit 32 is the LSB of (addr+1).
48 */
49
50static inline int ffz(unsigned long x)
51{
52 return 31 - __cntlz(~x & -~x);
53}
54
55/*
56 * __ffs: Find first bit set in word. Return 0 for bit 0
57 */
58
59static inline int __ffs(unsigned long x)
60{
61 return 31 - __cntlz(x & -x);
62}
63
64/*
65 * ffs: Find first bit set in word. This is defined the same way as
66 * the libc and compiler builtin ffs routines, therefore
67 * differs in spirit from the above ffz (man ffs).
68 */
69
70static inline int ffs(unsigned long x)
71{
72 return 32 - __cntlz(x & -x);
73}
74
75/*
76 * fls: Find last (most-significant) bit set in word.
77 * Note fls(0) = 0, fls(1) = 1, fls(0x80000000) = 32.
78 */
79
80static inline int fls (unsigned int x)
81{
82 return 32 - __cntlz(x);
83}
84
85#else
86
87/* Use the generic implementation if we don't have the nsa/nsau instructions. */
88
89# include <asm-generic/bitops/ffs.h>
90# include <asm-generic/bitops/__ffs.h>
91# include <asm-generic/bitops/ffz.h>
92# include <asm-generic/bitops/fls.h>
93
94#endif
95
96#include <asm-generic/bitops/fls64.h>
97#include <asm-generic/bitops/find.h>
98#include <asm-generic/bitops/ext2-non-atomic.h>
99
100#ifdef __XTENSA_EL__
101# define ext2_set_bit_atomic(lock,nr,addr) \
102 test_and_set_bit((nr), (unsigned long*)(addr))
103# define ext2_clear_bit_atomic(lock,nr,addr) \
104 test_and_clear_bit((nr), (unsigned long*)(addr))
105#elif defined(__XTENSA_EB__)
106# define ext2_set_bit_atomic(lock,nr,addr) \
107 test_and_set_bit((nr) ^ 0x18, (unsigned long*)(addr))
108# define ext2_clear_bit_atomic(lock,nr,addr) \
109 test_and_clear_bit((nr) ^ 0x18, (unsigned long*)(addr))
110#else
111# error processor byte order undefined!
112#endif
113
114#include <asm-generic/bitops/hweight.h>
115#include <asm-generic/bitops/lock.h>
116#include <asm-generic/bitops/sched.h>
117#include <asm-generic/bitops/minix.h>
118
119#endif /* __KERNEL__ */
120
121#endif /* _XTENSA_BITOPS_H */