bitops.h revision f2ea0f5f04c97b48c88edccba52b0682fbe45087 
1#ifndef _LINUX_BITOPS_H
2#define _LINUX_BITOPS_H
3#include <asm/types.h>
4
5#ifdef	__KERNEL__
6#define BIT(nr)			(1UL << (nr))
7#define BIT_MASK(nr)		(1UL << ((nr) % BITS_PER_LONG))
8#define BIT_WORD(nr)		((nr) / BITS_PER_LONG)
9#define BITS_PER_BYTE		8
10#define BITS_TO_LONGS(nr)	DIV_ROUND_UP(nr, BITS_PER_BYTE * sizeof(long))
11#endif
12
13extern unsigned int __sw_hweight8(unsigned int w);
14extern unsigned int __sw_hweight16(unsigned int w);
15extern unsigned int __sw_hweight32(unsigned int w);
16extern unsigned long __sw_hweight64(__u64 w);
17
18/*
19 * Include this here because some architectures need generic_ffs/fls in
20 * scope
21 */
22#include <asm/bitops.h>
23
24#define for_each_set_bit(bit, addr, size) \
25	for ((bit) = find_first_bit((addr), (size)); \
26	     (bit) < (size); \
27	     (bit) = find_next_bit((addr), (size), (bit) + 1))
28
29static __inline__ int get_bitmask_order(unsigned int count)
30{
31	int order;
32
33	order = fls(count);
34	return order;	/* We could be slightly more clever with -1 here... */
35}
36
37static __inline__ int get_count_order(unsigned int count)
38{
39	int order;
40
41	order = fls(count) - 1;
42	if (count & (count - 1))
43		order++;
44	return order;
45}
46
47static inline unsigned long hweight_long(unsigned long w)
48{
49	return sizeof(w) == 4 ? hweight32(w) : hweight64(w);
50}
51
52/**
53 * rol64 - rotate a 64-bit value left
54 * @word: value to rotate
55 * @shift: bits to roll
56 */
57static inline __u64 rol64(__u64 word, unsigned int shift)
58{
59	return (word << shift) | (word >> (64 - shift));
60}
61
62/**
63 * ror64 - rotate a 64-bit value right
64 * @word: value to rotate
65 * @shift: bits to roll
66 */
67static inline __u64 ror64(__u64 word, unsigned int shift)
68{
69	return (word >> shift) | (word << (64 - shift));
70}
71
72/**
73 * rol32 - rotate a 32-bit value left
74 * @word: value to rotate
75 * @shift: bits to roll
76 */
77static inline __u32 rol32(__u32 word, unsigned int shift)
78{
79	return (word << shift) | (word >> (32 - shift));
80}
81
82/**
83 * ror32 - rotate a 32-bit value right
84 * @word: value to rotate
85 * @shift: bits to roll
86 */
87static inline __u32 ror32(__u32 word, unsigned int shift)
88{
89	return (word >> shift) | (word << (32 - shift));
90}
91
92/**
93 * rol16 - rotate a 16-bit value left
94 * @word: value to rotate
95 * @shift: bits to roll
96 */
97static inline __u16 rol16(__u16 word, unsigned int shift)
98{
99	return (word << shift) | (word >> (16 - shift));
100}
101
102/**
103 * ror16 - rotate a 16-bit value right
104 * @word: value to rotate
105 * @shift: bits to roll
106 */
107static inline __u16 ror16(__u16 word, unsigned int shift)
108{
109	return (word >> shift) | (word << (16 - shift));
110}
111
112/**
113 * rol8 - rotate an 8-bit value left
114 * @word: value to rotate
115 * @shift: bits to roll
116 */
117static inline __u8 rol8(__u8 word, unsigned int shift)
118{
119	return (word << shift) | (word >> (8 - shift));
120}
121
122/**
123 * ror8 - rotate an 8-bit value right
124 * @word: value to rotate
125 * @shift: bits to roll
126 */
127static inline __u8 ror8(__u8 word, unsigned int shift)
128{
129	return (word >> shift) | (word << (8 - shift));
130}
131
132/**
133 * sign_extend32 - sign extend a 32-bit value using specified bit as sign-bit
134 * @value: value to sign extend
135 * @index: 0 based bit index (0<=index<32) to sign bit
136 */
137static inline __s32 sign_extend32(__u32 value, int index)
138{
139	__u8 shift = 31 - index;
140	return (__s32)(value << shift) >> shift;
141}
142
143static inline unsigned fls_long(unsigned long l)
144{
145	if (sizeof(l) == 4)
146		return fls(l);
147	return fls64(l);
148}
149
150/**
151 * __ffs64 - find first set bit in a 64 bit word
152 * @word: The 64 bit word
153 *
154 * On 64 bit arches this is a synomyn for __ffs
155 * The result is not defined if no bits are set, so check that @word
156 * is non-zero before calling this.
157 */
158static inline unsigned long __ffs64(u64 word)
159{
160#if BITS_PER_LONG == 32
161	if (((u32)word) == 0UL)
162		return __ffs((u32)(word >> 32)) + 32;
163#elif BITS_PER_LONG != 64
164#error BITS_PER_LONG not 32 or 64
165#endif
166	return __ffs((unsigned long)word);
167}
168
169#ifdef __KERNEL__
170
171#ifndef find_last_bit
172/**
173 * find_last_bit - find the last set bit in a memory region
174 * @addr: The address to start the search at
175 * @size: The maximum size to search
176 *
177 * Returns the bit number of the first set bit, or size.
178 */
179extern unsigned long find_last_bit(const unsigned long *addr,
180				   unsigned long size);
181#endif
182
183#endif /* __KERNEL__ */
184#endif
185