1 /* SPDX-License-Identifier: GPL-2.0 */
2 #ifndef _LINUX_BITOPS_H
3 #define _LINUX_BITOPS_H
4 
5 #include <asm/types.h>
6 #include <linux/bits.h>
7 #include <linux/typecheck.h>
8 
9 #include <uapi/linux/kernel.h>
10 
11 /* Set bits in the first 'n' bytes when loaded from memory */
12 #ifdef __LITTLE_ENDIAN
13 #  define aligned_byte_mask(n) ((1UL << 8*(n))-1)
14 #else
15 #  define aligned_byte_mask(n) (~0xffUL << (BITS_PER_LONG - 8 - 8*(n)))
16 #endif
17 
18 #define BITS_PER_TYPE(type)	(sizeof(type) * BITS_PER_BYTE)
19 #define BITS_TO_LONGS(nr)	__KERNEL_DIV_ROUND_UP(nr, BITS_PER_TYPE(long))
20 #define BITS_TO_U64(nr)		__KERNEL_DIV_ROUND_UP(nr, BITS_PER_TYPE(u64))
21 #define BITS_TO_U32(nr)		__KERNEL_DIV_ROUND_UP(nr, BITS_PER_TYPE(u32))
22 #define BITS_TO_BYTES(nr)	__KERNEL_DIV_ROUND_UP(nr, BITS_PER_TYPE(char))
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 
get_bitmask_order(unsigned int count)35 static inline int get_bitmask_order(unsigned int count)
36 {
37 	int order;
38 
39 	order = fls(count);
40 	return order;	/* We could be slightly more clever with -1 here... */
41 }
42 
hweight_long(unsigned long w)43 static __always_inline unsigned long hweight_long(unsigned long w)
44 {
45 	return sizeof(w) == 4 ? hweight32(w) : hweight64((__u64)w);
46 }
47 
48 /**
49  * rol64 - rotate a 64-bit value left
50  * @word: value to rotate
51  * @shift: bits to roll
52  */
rol64(__u64 word,unsigned int shift)53 static inline __u64 rol64(__u64 word, unsigned int shift)
54 {
55 	return (word << (shift & 63)) | (word >> ((-shift) & 63));
56 }
57 
58 /**
59  * ror64 - rotate a 64-bit value right
60  * @word: value to rotate
61  * @shift: bits to roll
62  */
ror64(__u64 word,unsigned int shift)63 static inline __u64 ror64(__u64 word, unsigned int shift)
64 {
65 	return (word >> (shift & 63)) | (word << ((-shift) & 63));
66 }
67 
68 /**
69  * rol32 - rotate a 32-bit value left
70  * @word: value to rotate
71  * @shift: bits to roll
72  */
rol32(__u32 word,unsigned int shift)73 static inline __u32 rol32(__u32 word, unsigned int shift)
74 {
75 	return (word << (shift & 31)) | (word >> ((-shift) & 31));
76 }
77 
78 /**
79  * ror32 - rotate a 32-bit value right
80  * @word: value to rotate
81  * @shift: bits to roll
82  */
ror32(__u32 word,unsigned int shift)83 static inline __u32 ror32(__u32 word, unsigned int shift)
84 {
85 	return (word >> (shift & 31)) | (word << ((-shift) & 31));
86 }
87 
88 /**
89  * rol16 - rotate a 16-bit value left
90  * @word: value to rotate
91  * @shift: bits to roll
92  */
rol16(__u16 word,unsigned int shift)93 static inline __u16 rol16(__u16 word, unsigned int shift)
94 {
95 	return (word << (shift & 15)) | (word >> ((-shift) & 15));
96 }
97 
98 /**
99  * ror16 - rotate a 16-bit value right
100  * @word: value to rotate
101  * @shift: bits to roll
102  */
ror16(__u16 word,unsigned int shift)103 static inline __u16 ror16(__u16 word, unsigned int shift)
104 {
105 	return (word >> (shift & 15)) | (word << ((-shift) & 15));
106 }
107 
108 /**
109  * rol8 - rotate an 8-bit value left
110  * @word: value to rotate
111  * @shift: bits to roll
112  */
rol8(__u8 word,unsigned int shift)113 static inline __u8 rol8(__u8 word, unsigned int shift)
114 {
115 	return (word << (shift & 7)) | (word >> ((-shift) & 7));
116 }
117 
118 /**
119  * ror8 - rotate an 8-bit value right
120  * @word: value to rotate
121  * @shift: bits to roll
122  */
ror8(__u8 word,unsigned int shift)123 static inline __u8 ror8(__u8 word, unsigned int shift)
124 {
125 	return (word >> (shift & 7)) | (word << ((-shift) & 7));
126 }
127 
128 /**
129  * sign_extend32 - sign extend a 32-bit value using specified bit as sign-bit
130  * @value: value to sign extend
131  * @index: 0 based bit index (0<=index<32) to sign bit
132  *
133  * This is safe to use for 16- and 8-bit types as well.
134  */
sign_extend32(__u32 value,int index)135 static __always_inline __s32 sign_extend32(__u32 value, int index)
136 {
137 	__u8 shift = 31 - index;
138 	return (__s32)(value << shift) >> shift;
139 }
140 
141 /**
142  * sign_extend64 - sign extend a 64-bit value using specified bit as sign-bit
143  * @value: value to sign extend
144  * @index: 0 based bit index (0<=index<64) to sign bit
145  */
sign_extend64(__u64 value,int index)146 static __always_inline __s64 sign_extend64(__u64 value, int index)
147 {
148 	__u8 shift = 63 - index;
149 	return (__s64)(value << shift) >> shift;
150 }
151 
fls_long(unsigned long l)152 static inline unsigned fls_long(unsigned long l)
153 {
154 	if (sizeof(l) == 4)
155 		return fls(l);
156 	return fls64(l);
157 }
158 
get_count_order(unsigned int count)159 static inline int get_count_order(unsigned int count)
160 {
161 	if (count == 0)
162 		return -1;
163 
164 	return fls(--count);
165 }
166 
167 /**
168  * get_count_order_long - get order after rounding @l up to power of 2
169  * @l: parameter
170  *
171  * it is same as get_count_order() but with long type parameter
172  */
get_count_order_long(unsigned long l)173 static inline int get_count_order_long(unsigned long l)
174 {
175 	if (l == 0UL)
176 		return -1;
177 	return (int)fls_long(--l);
178 }
179 
180 /**
181  * __ffs64 - find first set bit in a 64 bit word
182  * @word: The 64 bit word
183  *
184  * On 64 bit arches this is a synonym for __ffs
185  * The result is not defined if no bits are set, so check that @word
186  * is non-zero before calling this.
187  */
__ffs64(u64 word)188 static inline unsigned long __ffs64(u64 word)
189 {
190 #if BITS_PER_LONG == 32
191 	if (((u32)word) == 0UL)
192 		return __ffs((u32)(word >> 32)) + 32;
193 #elif BITS_PER_LONG != 64
194 #error BITS_PER_LONG not 32 or 64
195 #endif
196 	return __ffs((unsigned long)word);
197 }
198 
199 /**
200  * assign_bit - Assign value to a bit in memory
201  * @nr: the bit to set
202  * @addr: the address to start counting from
203  * @value: the value to assign
204  */
assign_bit(long nr,volatile unsigned long * addr,bool value)205 static __always_inline void assign_bit(long nr, volatile unsigned long *addr,
206 				       bool value)
207 {
208 	if (value)
209 		set_bit(nr, addr);
210 	else
211 		clear_bit(nr, addr);
212 }
213 
__assign_bit(long nr,volatile unsigned long * addr,bool value)214 static __always_inline void __assign_bit(long nr, volatile unsigned long *addr,
215 					 bool value)
216 {
217 	if (value)
218 		__set_bit(nr, addr);
219 	else
220 		__clear_bit(nr, addr);
221 }
222 
223 /**
224  * __ptr_set_bit - Set bit in a pointer's value
225  * @nr: the bit to set
226  * @addr: the address of the pointer variable
227  *
228  * Example:
229  *	void *p = foo();
230  *	__ptr_set_bit(bit, &p);
231  */
232 #define __ptr_set_bit(nr, addr)                         \
233 	({                                              \
234 		typecheck_pointer(*(addr));             \
235 		__set_bit(nr, (unsigned long *)(addr)); \
236 	})
237 
238 /**
239  * __ptr_clear_bit - Clear bit in a pointer's value
240  * @nr: the bit to clear
241  * @addr: the address of the pointer variable
242  *
243  * Example:
244  *	void *p = foo();
245  *	__ptr_clear_bit(bit, &p);
246  */
247 #define __ptr_clear_bit(nr, addr)                         \
248 	({                                                \
249 		typecheck_pointer(*(addr));               \
250 		__clear_bit(nr, (unsigned long *)(addr)); \
251 	})
252 
253 /**
254  * __ptr_test_bit - Test bit in a pointer's value
255  * @nr: the bit to test
256  * @addr: the address of the pointer variable
257  *
258  * Example:
259  *	void *p = foo();
260  *	if (__ptr_test_bit(bit, &p)) {
261  *	        ...
262  *	} else {
263  *		...
264  *	}
265  */
266 #define __ptr_test_bit(nr, addr)                       \
267 	({                                             \
268 		typecheck_pointer(*(addr));            \
269 		test_bit(nr, (unsigned long *)(addr)); \
270 	})
271 
272 #ifdef __KERNEL__
273 
274 #ifndef set_mask_bits
275 #define set_mask_bits(ptr, mask, bits)	\
276 ({								\
277 	const typeof(*(ptr)) mask__ = (mask), bits__ = (bits);	\
278 	typeof(*(ptr)) old__, new__;				\
279 								\
280 	do {							\
281 		old__ = READ_ONCE(*(ptr));			\
282 		new__ = (old__ & ~mask__) | bits__;		\
283 	} while (cmpxchg(ptr, old__, new__) != old__);		\
284 								\
285 	old__;							\
286 })
287 #endif
288 
289 #ifndef bit_clear_unless
290 #define bit_clear_unless(ptr, clear, test)	\
291 ({								\
292 	const typeof(*(ptr)) clear__ = (clear), test__ = (test);\
293 	typeof(*(ptr)) old__, new__;				\
294 								\
295 	do {							\
296 		old__ = READ_ONCE(*(ptr));			\
297 		new__ = old__ & ~clear__;			\
298 	} while (!(old__ & test__) &&				\
299 		 cmpxchg(ptr, old__, new__) != old__);		\
300 								\
301 	!(old__ & test__);					\
302 })
303 #endif
304 
305 #endif /* __KERNEL__ */
306 #endif
307