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