aboutsummaryrefslogtreecommitdiff
path: root/include/asm-xtensa/bitops.h
blob: 6c3930397bd32539716f51c0cd23a290efa74cdd (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
/*
 * include/asm-xtensa/bitops.h
 *
 * Atomic operations that C can't guarantee us.Useful for resource counting etc.
 *
 * This file is subject to the terms and conditions of the GNU General Public
 * License.  See the file "COPYING" in the main directory of this archive
 * for more details.
 *
 * Copyright (C) 2001 - 2007 Tensilica Inc.
 */

#ifndef _XTENSA_BITOPS_H
#define _XTENSA_BITOPS_H

#ifdef __KERNEL__

#ifndef _LINUX_BITOPS_H
#error only <linux/bitops.h> can be included directly
#endif

#include <asm/processor.h>
#include <asm/byteorder.h>
#include <asm/system.h>

#ifdef CONFIG_SMP
# error SMP not supported on this architecture
#endif

#define smp_mb__before_clear_bit()	barrier()
#define smp_mb__after_clear_bit()	barrier()

#include <asm-generic/bitops/atomic.h>
#include <asm-generic/bitops/non-atomic.h>

#if XCHAL_HAVE_NSA

static inline unsigned long __cntlz (unsigned long x)
{
	int lz;
	asm ("nsau %0, %1" : "=r" (lz) : "r" (x));
	return lz;
}

/*
 * ffz: Find first zero in word. Undefined if no zero exists.
 * bit 0 is the LSB of addr; bit 32 is the LSB of (addr+1).
 */

static inline int ffz(unsigned long x)
{
	return 31 - __cntlz(~x & -~x);
}

/*
 * __ffs: Find first bit set in word. Return 0 for bit 0
 */

static inline int __ffs(unsigned long x)
{
	return 31 - __cntlz(x & -x);
}

/*
 * ffs: Find first bit set in word. This is defined the same way as
 * the libc and compiler builtin ffs routines, therefore
 * differs in spirit from the above ffz (man ffs).
 */

static inline int ffs(unsigned long x)
{
	return 32 - __cntlz(x & -x);
}

/*
 * fls: Find last (most-significant) bit set in word.
 * Note fls(0) = 0, fls(1) = 1, fls(0x80000000) = 32.
 */

static inline int fls (unsigned int x)
{
	return 32 - __cntlz(x);
}

/**
 * __fls - find last (most-significant) set bit in a long word
 * @word: the word to search
 *
 * Undefined if no set bit exists, so code should check against 0 first.
 */
static inline unsigned long __fls(unsigned long word)
{
	return 31 - __cntlz(word);
}
#else

/* Use the generic implementation if we don't have the nsa/nsau instructions. */

# include <asm-generic/bitops/ffs.h>
# include <asm-generic/bitops/__ffs.h>
# include <asm-generic/bitops/ffz.h>
# include <asm-generic/bitops/fls.h>
# include <asm-generic/bitops/__fls.h>

#endif

#include <asm-generic/bitops/fls64.h>
#include <asm-generic/bitops/find.h>
#include <asm-generic/bitops/ext2-non-atomic.h>

#ifdef __XTENSA_EL__
# define ext2_set_bit_atomic(lock,nr,addr)				\
	test_and_set_bit((nr), (unsigned long*)(addr))
# define ext2_clear_bit_atomic(lock,nr,addr)				\
	test_and_clear_bit((nr), (unsigned long*)(addr))
#elif defined(__XTENSA_EB__)
# define ext2_set_bit_atomic(lock,nr,addr)				\
	test_and_set_bit((nr) ^ 0x18, (unsigned long*)(addr))
# define ext2_clear_bit_atomic(lock,nr,addr)				\
	test_and_clear_bit((nr) ^ 0x18, (unsigned long*)(addr))
#else
# error processor byte order undefined!
#endif

#include <asm-generic/bitops/hweight.h>
#include <asm-generic/bitops/lock.h>
#include <asm-generic/bitops/sched.h>
#include <asm-generic/bitops/minix.h>

#endif	/* __KERNEL__ */

#endif	/* _XTENSA_BITOPS_H */