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1 /* SPDX-License-Identifier: GPL-2.0 */
2 #ifndef _LINUX_BITOPS_H
3 #define _LINUX_BITOPS_H
4 #include <asm/types.h>
5 #include <linux/bits.h>
6 
7 /* Set bits in the first 'n' bytes when loaded from memory */
8 #ifdef __LITTLE_ENDIAN
9 #  define aligned_byte_mask(n) ((1UL << 8*(n))-1)
10 #else
11 #  define aligned_byte_mask(n) (~0xffUL << (BITS_PER_LONG - 8 - 8*(n)))
12 #endif
13 
14 #define BITS_PER_TYPE(type)	(sizeof(type) * BITS_PER_BYTE)
15 #define BITS_TO_LONGS(nr)	DIV_ROUND_UP(nr, BITS_PER_TYPE(long))
16 #define BITS_TO_U64(nr)		DIV_ROUND_UP(nr, BITS_PER_TYPE(u64))
17 #define BITS_TO_U32(nr)		DIV_ROUND_UP(nr, BITS_PER_TYPE(u32))
18 #define BITS_TO_BYTES(nr)	DIV_ROUND_UP(nr, BITS_PER_TYPE(char))
19 
20 extern unsigned int __sw_hweight8(unsigned int w);
21 extern unsigned int __sw_hweight16(unsigned int w);
22 extern unsigned int __sw_hweight32(unsigned int w);
23 extern unsigned long __sw_hweight64(__u64 w);
24 
25 /*
26  * Include this here because some architectures need generic_ffs/fls in
27  * scope
28  */
29 #include <asm/bitops.h>
30 
31 #define for_each_set_bit(bit, addr, size) \
32 	for ((bit) = find_first_bit((addr), (size));		\
33 	     (bit) < (size);					\
34 	     (bit) = find_next_bit((addr), (size), (bit) + 1))
35 
36 /* same as for_each_set_bit() but use bit as value to start with */
37 #define for_each_set_bit_from(bit, addr, size) \
38 	for ((bit) = find_next_bit((addr), (size), (bit));	\
39 	     (bit) < (size);					\
40 	     (bit) = find_next_bit((addr), (size), (bit) + 1))
41 
42 #define for_each_clear_bit(bit, addr, size) \
43 	for ((bit) = find_first_zero_bit((addr), (size));	\
44 	     (bit) < (size);					\
45 	     (bit) = find_next_zero_bit((addr), (size), (bit) + 1))
46 
47 /* same as for_each_clear_bit() but use bit as value to start with */
48 #define for_each_clear_bit_from(bit, addr, size) \
49 	for ((bit) = find_next_zero_bit((addr), (size), (bit));	\
50 	     (bit) < (size);					\
51 	     (bit) = find_next_zero_bit((addr), (size), (bit) + 1))
52 
53 /**
54  * for_each_set_clump8 - iterate over bitmap for each 8-bit clump with set bits
55  * @start: bit offset to start search and to store the current iteration offset
56  * @clump: location to store copy of current 8-bit clump
57  * @bits: bitmap address to base the search on
58  * @size: bitmap size in number of bits
59  */
60 #define for_each_set_clump8(start, clump, bits, size) \
61 	for ((start) = find_first_clump8(&(clump), (bits), (size)); \
62 	     (start) < (size); \
63 	     (start) = find_next_clump8(&(clump), (bits), (size), (start) + 8))
64 
get_bitmask_order(unsigned int count)65 static inline int get_bitmask_order(unsigned int count)
66 {
67 	int order;
68 
69 	order = fls(count);
70 	return order;	/* We could be slightly more clever with -1 here... */
71 }
72 
hweight_long(unsigned long w)73 static __always_inline unsigned long hweight_long(unsigned long w)
74 {
75 	return sizeof(w) == 4 ? hweight32(w) : hweight64((__u64)w);
76 }
77 
78 /**
79  * rol64 - rotate a 64-bit value left
80  * @word: value to rotate
81  * @shift: bits to roll
82  */
rol64(__u64 word,unsigned int shift)83 static inline __u64 rol64(__u64 word, unsigned int shift)
84 {
85 	return (word << (shift & 63)) | (word >> ((-shift) & 63));
86 }
87 
88 /**
89  * ror64 - rotate a 64-bit value right
90  * @word: value to rotate
91  * @shift: bits to roll
92  */
ror64(__u64 word,unsigned int shift)93 static inline __u64 ror64(__u64 word, unsigned int shift)
94 {
95 	return (word >> (shift & 63)) | (word << ((-shift) & 63));
96 }
97 
98 /**
99  * rol32 - rotate a 32-bit value left
100  * @word: value to rotate
101  * @shift: bits to roll
102  */
rol32(__u32 word,unsigned int shift)103 static inline __u32 rol32(__u32 word, unsigned int shift)
104 {
105 	return (word << (shift & 31)) | (word >> ((-shift) & 31));
106 }
107 
108 /**
109  * ror32 - rotate a 32-bit value right
110  * @word: value to rotate
111  * @shift: bits to roll
112  */
ror32(__u32 word,unsigned int shift)113 static inline __u32 ror32(__u32 word, unsigned int shift)
114 {
115 	return (word >> (shift & 31)) | (word << ((-shift) & 31));
116 }
117 
118 /**
119  * rol16 - rotate a 16-bit value left
120  * @word: value to rotate
121  * @shift: bits to roll
122  */
rol16(__u16 word,unsigned int shift)123 static inline __u16 rol16(__u16 word, unsigned int shift)
124 {
125 	return (word << (shift & 15)) | (word >> ((-shift) & 15));
126 }
127 
128 /**
129  * ror16 - rotate a 16-bit value right
130  * @word: value to rotate
131  * @shift: bits to roll
132  */
ror16(__u16 word,unsigned int shift)133 static inline __u16 ror16(__u16 word, unsigned int shift)
134 {
135 	return (word >> (shift & 15)) | (word << ((-shift) & 15));
136 }
137 
138 /**
139  * rol8 - rotate an 8-bit value left
140  * @word: value to rotate
141  * @shift: bits to roll
142  */
rol8(__u8 word,unsigned int shift)143 static inline __u8 rol8(__u8 word, unsigned int shift)
144 {
145 	return (word << (shift & 7)) | (word >> ((-shift) & 7));
146 }
147 
148 /**
149  * ror8 - rotate an 8-bit value right
150  * @word: value to rotate
151  * @shift: bits to roll
152  */
ror8(__u8 word,unsigned int shift)153 static inline __u8 ror8(__u8 word, unsigned int shift)
154 {
155 	return (word >> (shift & 7)) | (word << ((-shift) & 7));
156 }
157 
158 /**
159  * sign_extend32 - sign extend a 32-bit value using specified bit as sign-bit
160  * @value: value to sign extend
161  * @index: 0 based bit index (0<=index<32) to sign bit
162  *
163  * This is safe to use for 16- and 8-bit types as well.
164  */
sign_extend32(__u32 value,int index)165 static __always_inline __s32 sign_extend32(__u32 value, int index)
166 {
167 	__u8 shift = 31 - index;
168 	return (__s32)(value << shift) >> shift;
169 }
170 
171 /**
172  * sign_extend64 - sign extend a 64-bit value using specified bit as sign-bit
173  * @value: value to sign extend
174  * @index: 0 based bit index (0<=index<64) to sign bit
175  */
sign_extend64(__u64 value,int index)176 static __always_inline __s64 sign_extend64(__u64 value, int index)
177 {
178 	__u8 shift = 63 - index;
179 	return (__s64)(value << shift) >> shift;
180 }
181 
fls_long(unsigned long l)182 static inline unsigned fls_long(unsigned long l)
183 {
184 	if (sizeof(l) == 4)
185 		return fls(l);
186 	return fls64(l);
187 }
188 
get_count_order(unsigned int count)189 static inline int get_count_order(unsigned int count)
190 {
191 	if (count == 0)
192 		return -1;
193 
194 	return fls(--count);
195 }
196 
197 /**
198  * get_count_order_long - get order after rounding @l up to power of 2
199  * @l: parameter
200  *
201  * it is same as get_count_order() but with long type parameter
202  */
get_count_order_long(unsigned long l)203 static inline int get_count_order_long(unsigned long l)
204 {
205 	if (l == 0UL)
206 		return -1;
207 	return (int)fls_long(--l);
208 }
209 
210 /**
211  * __ffs64 - find first set bit in a 64 bit word
212  * @word: The 64 bit word
213  *
214  * On 64 bit arches this is a synomyn for __ffs
215  * The result is not defined if no bits are set, so check that @word
216  * is non-zero before calling this.
217  */
__ffs64(u64 word)218 static inline unsigned long __ffs64(u64 word)
219 {
220 #if BITS_PER_LONG == 32
221 	if (((u32)word) == 0UL)
222 		return __ffs((u32)(word >> 32)) + 32;
223 #elif BITS_PER_LONG != 64
224 #error BITS_PER_LONG not 32 or 64
225 #endif
226 	return __ffs((unsigned long)word);
227 }
228 
229 /**
230  * assign_bit - Assign value to a bit in memory
231  * @nr: the bit to set
232  * @addr: the address to start counting from
233  * @value: the value to assign
234  */
assign_bit(long nr,volatile unsigned long * addr,bool value)235 static __always_inline void assign_bit(long nr, volatile unsigned long *addr,
236 				       bool value)
237 {
238 	if (value)
239 		set_bit(nr, addr);
240 	else
241 		clear_bit(nr, addr);
242 }
243 
__assign_bit(long nr,volatile unsigned long * addr,bool value)244 static __always_inline void __assign_bit(long nr, volatile unsigned long *addr,
245 					 bool value)
246 {
247 	if (value)
248 		__set_bit(nr, addr);
249 	else
250 		__clear_bit(nr, addr);
251 }
252 
253 #ifdef __KERNEL__
254 
255 #ifndef set_mask_bits
256 #define set_mask_bits(ptr, mask, bits)	\
257 ({								\
258 	const typeof(*(ptr)) mask__ = (mask), bits__ = (bits);	\
259 	typeof(*(ptr)) old__, new__;				\
260 								\
261 	do {							\
262 		old__ = READ_ONCE(*(ptr));			\
263 		new__ = (old__ & ~mask__) | bits__;		\
264 	} while (cmpxchg(ptr, old__, new__) != old__);		\
265 								\
266 	old__;							\
267 })
268 #endif
269 
270 #ifndef bit_clear_unless
271 #define bit_clear_unless(ptr, clear, test)	\
272 ({								\
273 	const typeof(*(ptr)) clear__ = (clear), test__ = (test);\
274 	typeof(*(ptr)) old__, new__;				\
275 								\
276 	do {							\
277 		old__ = READ_ONCE(*(ptr));			\
278 		new__ = old__ & ~clear__;			\
279 	} while (!(old__ & test__) &&				\
280 		 cmpxchg(ptr, old__, new__) != old__);		\
281 								\
282 	!(old__ & test__);					\
283 })
284 #endif
285 
286 #ifndef find_last_bit
287 /**
288  * find_last_bit - find the last set bit in a memory region
289  * @addr: The address to start the search at
290  * @size: The number of bits to search
291  *
292  * Returns the bit number of the last set bit, or size.
293  */
294 extern unsigned long find_last_bit(const unsigned long *addr,
295 				   unsigned long size);
296 #endif
297 
298 #endif /* __KERNEL__ */
299 #endif
300