xref: /freebsd/sys/compat/linuxkpi/common/include/linux/bitops.h (revision 4d846d260e2b9a3d4d0a701462568268cbfe7a5b)
1 /*-
2  * Copyright (c) 2010 Isilon Systems, Inc.
3  * Copyright (c) 2010 iX Systems, Inc.
4  * Copyright (c) 2010 Panasas, Inc.
5  * Copyright (c) 2013-2017 Mellanox Technologies, Ltd.
6  * All rights reserved.
7  *
8  * Redistribution and use in source and binary forms, with or without
9  * modification, are permitted provided that the following conditions
10  * are met:
11  * 1. Redistributions of source code must retain the above copyright
12  *    notice unmodified, this list of conditions, and the following
13  *    disclaimer.
14  * 2. Redistributions in binary form must reproduce the above copyright
15  *    notice, this list of conditions and the following disclaimer in the
16  *    documentation and/or other materials provided with the distribution.
17  *
18  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
19  * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
20  * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
21  * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
22  * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
23  * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
24  * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
25  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
26  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
27  * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
28  *
29  * $FreeBSD$
30  */
31 #ifndef	_LINUXKPI_LINUX_BITOPS_H_
32 #define	_LINUXKPI_LINUX_BITOPS_H_
33 
34 #include <sys/param.h>
35 #include <sys/types.h>
36 #include <sys/systm.h>
37 #include <sys/errno.h>
38 #include <sys/libkern.h>
39 
40 #define	BIT(nr)			(1UL << (nr))
41 #define	BIT_ULL(nr)		(1ULL << (nr))
42 #ifdef __LP64__
43 #define	BITS_PER_LONG		64
44 #else
45 #define	BITS_PER_LONG		32
46 #endif
47 
48 #define	BITS_PER_LONG_LONG	64
49 
50 #define	BITMAP_FIRST_WORD_MASK(start)	(~0UL << ((start) % BITS_PER_LONG))
51 #define	BITMAP_LAST_WORD_MASK(n)	(~0UL >> (BITS_PER_LONG - (n)))
52 #define	BITS_TO_LONGS(n)	howmany((n), BITS_PER_LONG)
53 #define	BIT_MASK(nr)		(1UL << ((nr) & (BITS_PER_LONG - 1)))
54 #define	BIT_WORD(nr)		((nr) / BITS_PER_LONG)
55 #define	GENMASK(h, l)		(((~0UL) >> (BITS_PER_LONG - (h) - 1)) & ((~0UL) << (l)))
56 #define	GENMASK_ULL(h, l)	(((~0ULL) >> (BITS_PER_LONG_LONG - (h) - 1)) & ((~0ULL) << (l)))
57 #define	BITS_PER_BYTE		8
58 #define	BITS_PER_TYPE(t)	(sizeof(t) * BITS_PER_BYTE)
59 
60 #define	hweight8(x)	bitcount((uint8_t)(x))
61 #define	hweight16(x)	bitcount16(x)
62 #define	hweight32(x)	bitcount32(x)
63 #define	hweight64(x)	bitcount64(x)
64 #define	hweight_long(x)	bitcountl(x)
65 
66 #define	HWEIGHT8(x)	(bitcount8((uint8_t)(x)) + 1)
67 #define	HWEIGHT16(x)	(bitcount16(x) + 1)
68 #define	HWEIGHT32(x)	(bitcount32(x) + 1)
69 #define	HWEIGHT64(x)	(bitcount64(x) + 1)
70 
71 static inline int
72 __ffs(int mask)
73 {
74 	return (ffs(mask) - 1);
75 }
76 
77 static inline int
78 __fls(int mask)
79 {
80 	return (fls(mask) - 1);
81 }
82 
83 static inline int
84 __ffsl(long mask)
85 {
86 	return (ffsl(mask) - 1);
87 }
88 
89 static inline unsigned long
90 __ffs64(uint64_t mask)
91 {
92 	return (ffsll(mask) - 1);
93 }
94 
95 static inline int
96 __flsl(long mask)
97 {
98 	return (flsl(mask) - 1);
99 }
100 
101 static inline int
102 fls64(uint64_t mask)
103 {
104 	return (flsll(mask));
105 }
106 
107 static inline uint32_t
108 ror32(uint32_t word, unsigned int shift)
109 {
110 	return ((word >> shift) | (word << (32 - shift)));
111 }
112 
113 #define	ffz(mask)	__ffs(~(mask))
114 
115 static inline int get_count_order(unsigned int count)
116 {
117         int order;
118 
119         order = fls(count) - 1;
120         if (count & (count - 1))
121                 order++;
122         return order;
123 }
124 
125 static inline unsigned long
126 find_first_bit(const unsigned long *addr, unsigned long size)
127 {
128 	long mask;
129 	int bit;
130 
131 	for (bit = 0; size >= BITS_PER_LONG;
132 	    size -= BITS_PER_LONG, bit += BITS_PER_LONG, addr++) {
133 		if (*addr == 0)
134 			continue;
135 		return (bit + __ffsl(*addr));
136 	}
137 	if (size) {
138 		mask = (*addr) & BITMAP_LAST_WORD_MASK(size);
139 		if (mask)
140 			bit += __ffsl(mask);
141 		else
142 			bit += size;
143 	}
144 	return (bit);
145 }
146 
147 static inline unsigned long
148 find_first_zero_bit(const unsigned long *addr, unsigned long size)
149 {
150 	long mask;
151 	int bit;
152 
153 	for (bit = 0; size >= BITS_PER_LONG;
154 	    size -= BITS_PER_LONG, bit += BITS_PER_LONG, addr++) {
155 		if (~(*addr) == 0)
156 			continue;
157 		return (bit + __ffsl(~(*addr)));
158 	}
159 	if (size) {
160 		mask = ~(*addr) & BITMAP_LAST_WORD_MASK(size);
161 		if (mask)
162 			bit += __ffsl(mask);
163 		else
164 			bit += size;
165 	}
166 	return (bit);
167 }
168 
169 static inline unsigned long
170 find_last_bit(const unsigned long *addr, unsigned long size)
171 {
172 	long mask;
173 	int offs;
174 	int bit;
175 	int pos;
176 
177 	pos = size / BITS_PER_LONG;
178 	offs = size % BITS_PER_LONG;
179 	bit = BITS_PER_LONG * pos;
180 	addr += pos;
181 	if (offs) {
182 		mask = (*addr) & BITMAP_LAST_WORD_MASK(offs);
183 		if (mask)
184 			return (bit + __flsl(mask));
185 	}
186 	while (pos--) {
187 		addr--;
188 		bit -= BITS_PER_LONG;
189 		if (*addr)
190 			return (bit + __flsl(*addr));
191 	}
192 	return (size);
193 }
194 
195 static inline unsigned long
196 find_next_bit(const unsigned long *addr, unsigned long size, unsigned long offset)
197 {
198 	long mask;
199 	int offs;
200 	int bit;
201 	int pos;
202 
203 	if (offset >= size)
204 		return (size);
205 	pos = offset / BITS_PER_LONG;
206 	offs = offset % BITS_PER_LONG;
207 	bit = BITS_PER_LONG * pos;
208 	addr += pos;
209 	if (offs) {
210 		mask = (*addr) & ~BITMAP_LAST_WORD_MASK(offs);
211 		if (mask)
212 			return (bit + __ffsl(mask));
213 		if (size - bit <= BITS_PER_LONG)
214 			return (size);
215 		bit += BITS_PER_LONG;
216 		addr++;
217 	}
218 	for (size -= bit; size >= BITS_PER_LONG;
219 	    size -= BITS_PER_LONG, bit += BITS_PER_LONG, addr++) {
220 		if (*addr == 0)
221 			continue;
222 		return (bit + __ffsl(*addr));
223 	}
224 	if (size) {
225 		mask = (*addr) & BITMAP_LAST_WORD_MASK(size);
226 		if (mask)
227 			bit += __ffsl(mask);
228 		else
229 			bit += size;
230 	}
231 	return (bit);
232 }
233 
234 static inline unsigned long
235 find_next_zero_bit(const unsigned long *addr, unsigned long size,
236     unsigned long offset)
237 {
238 	long mask;
239 	int offs;
240 	int bit;
241 	int pos;
242 
243 	if (offset >= size)
244 		return (size);
245 	pos = offset / BITS_PER_LONG;
246 	offs = offset % BITS_PER_LONG;
247 	bit = BITS_PER_LONG * pos;
248 	addr += pos;
249 	if (offs) {
250 		mask = ~(*addr) & ~BITMAP_LAST_WORD_MASK(offs);
251 		if (mask)
252 			return (bit + __ffsl(mask));
253 		if (size - bit <= BITS_PER_LONG)
254 			return (size);
255 		bit += BITS_PER_LONG;
256 		addr++;
257 	}
258 	for (size -= bit; size >= BITS_PER_LONG;
259 	    size -= BITS_PER_LONG, bit += BITS_PER_LONG, addr++) {
260 		if (~(*addr) == 0)
261 			continue;
262 		return (bit + __ffsl(~(*addr)));
263 	}
264 	if (size) {
265 		mask = ~(*addr) & BITMAP_LAST_WORD_MASK(size);
266 		if (mask)
267 			bit += __ffsl(mask);
268 		else
269 			bit += size;
270 	}
271 	return (bit);
272 }
273 
274 #define	__set_bit(i, a)							\
275     atomic_set_long(&((volatile unsigned long *)(a))[BIT_WORD(i)], BIT_MASK(i))
276 
277 #define	set_bit(i, a)							\
278     atomic_set_long(&((volatile unsigned long *)(a))[BIT_WORD(i)], BIT_MASK(i))
279 
280 #define	__clear_bit(i, a)						\
281     atomic_clear_long(&((volatile unsigned long *)(a))[BIT_WORD(i)], BIT_MASK(i))
282 
283 #define	clear_bit(i, a)							\
284     atomic_clear_long(&((volatile unsigned long *)(a))[BIT_WORD(i)], BIT_MASK(i))
285 
286 #define	clear_bit_unlock(i, a)						\
287     atomic_clear_rel_long(&((volatile unsigned long *)(a))[BIT_WORD(i)], BIT_MASK(i))
288 
289 #define	test_bit(i, a)							\
290     !!(READ_ONCE(((volatile const unsigned long *)(a))[BIT_WORD(i)]) & BIT_MASK(i))
291 
292 static inline int
293 test_and_clear_bit(long bit, volatile unsigned long *var)
294 {
295 	long val;
296 
297 	var += BIT_WORD(bit);
298 	bit %= BITS_PER_LONG;
299 	bit = (1UL << bit);
300 
301 	val = *var;
302 	while (!atomic_fcmpset_long(var, &val, val & ~bit))
303 		;
304 	return !!(val & bit);
305 }
306 
307 static inline int
308 __test_and_clear_bit(long bit, volatile unsigned long *var)
309 {
310 	long val;
311 
312 	var += BIT_WORD(bit);
313 	bit %= BITS_PER_LONG;
314 	bit = (1UL << bit);
315 
316 	val = *var;
317 	*var &= ~bit;
318 
319 	return !!(val & bit);
320 }
321 
322 static inline int
323 test_and_set_bit(long bit, volatile unsigned long *var)
324 {
325 	long val;
326 
327 	var += BIT_WORD(bit);
328 	bit %= BITS_PER_LONG;
329 	bit = (1UL << bit);
330 
331 	val = *var;
332 	while (!atomic_fcmpset_long(var, &val, val | bit))
333 		;
334 	return !!(val & bit);
335 }
336 
337 static inline int
338 __test_and_set_bit(long bit, volatile unsigned long *var)
339 {
340 	long val;
341 
342 	var += BIT_WORD(bit);
343 	bit %= BITS_PER_LONG;
344 	bit = (1UL << bit);
345 
346 	val = *var;
347 	*var |= bit;
348 
349 	return !!(val & bit);
350 }
351 
352 enum {
353         REG_OP_ISFREE,
354         REG_OP_ALLOC,
355         REG_OP_RELEASE,
356 };
357 
358 static inline int
359 linux_reg_op(unsigned long *bitmap, int pos, int order, int reg_op)
360 {
361         int nbits_reg;
362         int index;
363         int offset;
364         int nlongs_reg;
365         int nbitsinlong;
366         unsigned long mask;
367         int i;
368         int ret = 0;
369 
370         nbits_reg = 1 << order;
371         index = pos / BITS_PER_LONG;
372         offset = pos - (index * BITS_PER_LONG);
373         nlongs_reg = BITS_TO_LONGS(nbits_reg);
374         nbitsinlong = MIN(nbits_reg,  BITS_PER_LONG);
375 
376         mask = (1UL << (nbitsinlong - 1));
377         mask += mask - 1;
378         mask <<= offset;
379 
380         switch (reg_op) {
381         case REG_OP_ISFREE:
382                 for (i = 0; i < nlongs_reg; i++) {
383                         if (bitmap[index + i] & mask)
384                                 goto done;
385                 }
386                 ret = 1;
387                 break;
388 
389         case REG_OP_ALLOC:
390                 for (i = 0; i < nlongs_reg; i++)
391                         bitmap[index + i] |= mask;
392                 break;
393 
394         case REG_OP_RELEASE:
395                 for (i = 0; i < nlongs_reg; i++)
396                         bitmap[index + i] &= ~mask;
397                 break;
398         }
399 done:
400         return ret;
401 }
402 
403 #define for_each_set_bit(bit, addr, size) \
404 	for ((bit) = find_first_bit((addr), (size));		\
405 	     (bit) < (size);					\
406 	     (bit) = find_next_bit((addr), (size), (bit) + 1))
407 
408 #define	for_each_clear_bit(bit, addr, size) \
409 	for ((bit) = find_first_zero_bit((addr), (size));		\
410 	     (bit) < (size);						\
411 	     (bit) = find_next_zero_bit((addr), (size), (bit) + 1))
412 
413 static inline uint64_t
414 sign_extend64(uint64_t value, int index)
415 {
416 	uint8_t shift = 63 - index;
417 
418 	return ((int64_t)(value << shift) >> shift);
419 }
420 
421 static inline uint32_t
422 sign_extend32(uint32_t value, int index)
423 {
424 	uint8_t shift = 31 - index;
425 
426 	return ((int32_t)(value << shift) >> shift);
427 }
428 
429 #endif	/* _LINUXKPI_LINUX_BITOPS_H_ */
430