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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_ULL(nr) (1ULL << (nr))
8 #define BIT_MASK(nr) (1UL << ((nr) % BITS_PER_LONG))
9 #define BIT_WORD(nr) ((nr) / BITS_PER_LONG)
10 #define BIT_ULL_MASK(nr) (1ULL << ((nr) % BITS_PER_LONG_LONG))
11 #define BIT_ULL_WORD(nr) ((nr) / BITS_PER_LONG_LONG)
12 #define BITS_PER_BYTE 8
13 #define BITS_TO_LONGS(nr) DIV_ROUND_UP(nr, BITS_PER_BYTE * sizeof(long))
14 #endif
15
16 /*
17 * Create a contiguous bitmask starting at bit position @l and ending at
18 * position @h. For example
19 * GENMASK_ULL(39, 21) gives us the 64bit vector 0x000000ffffe00000.
20 */
21 #define GENMASK(h, l) (((U32_C(1) << ((h) - (l) + 1)) - 1) << (l))
22 #define GENMASK_ULL(h, l) (((U64_C(1) << ((h) - (l) + 1)) - 1) << (l))
23
24 extern unsigned int __sw_hweight8(unsigned int w);
25 extern unsigned int __sw_hweight16(unsigned int w);
26 extern unsigned int __sw_hweight32(unsigned int w);
27 extern unsigned long __sw_hweight64(__u64 w);
28
29 /*
30 * Include this here because some architectures need generic_ffs/fls in
31 * scope
32 */
33 #include <asm/bitops.h>
34
35 #define for_each_set_bit(bit, addr, size) \
36 for ((bit) = find_first_bit((addr), (size)); \
37 (bit) < (size); \
38 (bit) = find_next_bit((addr), (size), (bit) + 1))
39
40 /* same as for_each_set_bit() but use bit as value to start with */
41 #define for_each_set_bit_from(bit, addr, size) \
42 for ((bit) = find_next_bit((addr), (size), (bit)); \
43 (bit) < (size); \
44 (bit) = find_next_bit((addr), (size), (bit) + 1))
45
46 #define for_each_clear_bit(bit, addr, size) \
47 for ((bit) = find_first_zero_bit((addr), (size)); \
48 (bit) < (size); \
49 (bit) = find_next_zero_bit((addr), (size), (bit) + 1))
50
51 /* same as for_each_clear_bit() but use bit as value to start with */
52 #define for_each_clear_bit_from(bit, addr, size) \
53 for ((bit) = find_next_zero_bit((addr), (size), (bit)); \
54 (bit) < (size); \
55 (bit) = find_next_zero_bit((addr), (size), (bit) + 1))
56
57 static __inline__ int get_bitmask_order(unsigned int count)
58 {
59 int order;
60
61 order = fls(count);
62 return order; /* We could be slightly more clever with -1 here... */
63 }
64
65 static __inline__ int get_count_order(unsigned int count)
66 {
67 int order;
68
69 order = fls(count) - 1;
70 if (count & (count - 1))
71 order++;
72 return order;
73 }
74
75 static inline unsigned long hweight_long(unsigned long w)
76 {
77 return sizeof(w) == 4 ? hweight32(w) : hweight64(w);
78 }
79
80 /**
81 * rol64 - rotate a 64-bit value left
82 * @word: value to rotate
83 * @shift: bits to roll
84 */
85 static inline __u64 rol64(__u64 word, unsigned int shift)
86 {
87 return (word << shift) | (word >> (64 - shift));
88 }
89
90 /**
91 * ror64 - rotate a 64-bit value right
92 * @word: value to rotate
93 * @shift: bits to roll
94 */
95 static inline __u64 ror64(__u64 word, unsigned int shift)
96 {
97 return (word >> shift) | (word << (64 - shift));
98 }
99
100 /**
101 * rol32 - rotate a 32-bit value left
102 * @word: value to rotate
103 * @shift: bits to roll
104 */
105 static inline __u32 rol32(__u32 word, unsigned int shift)
106 {
107 return (word << shift) | (word >> (32 - shift));
108 }
109
110 /**
111 * ror32 - rotate a 32-bit value right
112 * @word: value to rotate
113 * @shift: bits to roll
114 */
115 static inline __u32 ror32(__u32 word, unsigned int shift)
116 {
117 return (word >> shift) | (word << (32 - shift));
118 }
119
120 /**
121 * rol16 - rotate a 16-bit value left
122 * @word: value to rotate
123 * @shift: bits to roll
124 */
125 static inline __u16 rol16(__u16 word, unsigned int shift)
126 {
127 return (word << shift) | (word >> (16 - shift));
128 }
129
130 /**
131 * ror16 - rotate a 16-bit value right
132 * @word: value to rotate
133 * @shift: bits to roll
134 */
135 static inline __u16 ror16(__u16 word, unsigned int shift)
136 {
137 return (word >> shift) | (word << (16 - shift));
138 }
139
140 /**
141 * rol8 - rotate an 8-bit value left
142 * @word: value to rotate
143 * @shift: bits to roll
144 */
145 static inline __u8 rol8(__u8 word, unsigned int shift)
146 {
147 return (word << shift) | (word >> (8 - shift));
148 }
149
150 /**
151 * ror8 - rotate an 8-bit value right
152 * @word: value to rotate
153 * @shift: bits to roll
154 */
155 static inline __u8 ror8(__u8 word, unsigned int shift)
156 {
157 return (word >> shift) | (word << (8 - shift));
158 }
159
160 /**
161 * sign_extend32 - sign extend a 32-bit value using specified bit as sign-bit
162 * @value: value to sign extend
163 * @index: 0 based bit index (0<=index<32) to sign bit
164 */
165 static inline __s32 sign_extend32(__u32 value, int index)
166 {
167 __u8 shift = 31 - index;
168 return (__s32)(value << shift) >> shift;
169 }
170
171 static inline unsigned fls_long(unsigned long l)
172 {
173 if (sizeof(l) == 4)
174 return fls(l);
175 return fls64(l);
176 }
177
178 /**
179 * __ffs64 - find first set bit in a 64 bit word
180 * @word: The 64 bit word
181 *
182 * On 64 bit arches this is a synomyn for __ffs
183 * The result is not defined if no bits are set, so check that @word
184 * is non-zero before calling this.
185 */
186 static inline unsigned long __ffs64(u64 word)
187 {
188 #if BITS_PER_LONG == 32
189 if (((u32)word) == 0UL)
190 return __ffs((u32)(word >> 32)) + 32;
191 #elif BITS_PER_LONG != 64
192 #error BITS_PER_LONG not 32 or 64
193 #endif
194 return __ffs((unsigned long)word);
195 }
196
197 #ifdef __KERNEL__
198
199 #ifndef set_mask_bits
200 #define set_mask_bits(ptr, _mask, _bits) \
201 ({ \
202 const typeof(*ptr) mask = (_mask), bits = (_bits); \
203 typeof(*ptr) old, new; \
204 \
205 do { \
206 old = ACCESS_ONCE(*ptr); \
207 new = (old & ~mask) | bits; \
208 } while (cmpxchg(ptr, old, new) != old); \
209 \
210 new; \
211 })
212 #endif
213
214 #ifndef find_last_bit
215 /**
216 * find_last_bit - find the last set bit in a memory region
217 * @addr: The address to start the search at
218 * @size: The maximum size to search
219 *
220 * Returns the bit number of the first set bit, or size.
221 */
222 extern unsigned long find_last_bit(const unsigned long *addr,
223 unsigned long size);
224 #endif
225
226 #endif /* __KERNEL__ */
227 #endif