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TOMOYO Linux Cross Reference
Linux/include/linux/bitops.h

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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
228 

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