xref: /freebsd/sys/contrib/openzfs/lib/libspl/atomic.c (revision 43a5ec4eb41567cc92586503212743d89686d78f)
1 /*
2  * CDDL HEADER START
3  *
4  * The contents of this file are subject to the terms of the
5  * Common Development and Distribution License, Version 1.0 only
6  * (the "License").  You may not use this file except in compliance
7  * with the License.
8  *
9  * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
10  * or http://www.opensolaris.org/os/licensing.
11  * See the License for the specific language governing permissions
12  * and limitations under the License.
13  *
14  * When distributing Covered Code, include this CDDL HEADER in each
15  * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
16  * If applicable, add the following below this CDDL HEADER, with the
17  * fields enclosed by brackets "[]" replaced with your own identifying
18  * information: Portions Copyright [yyyy] [name of copyright owner]
19  *
20  * CDDL HEADER END
21  */
22 /*
23  * Copyright (c) 2009 by Sun Microsystems, Inc.  All rights reserved.
24  * Use is subject to license terms.
25  */
26 
27 #include <atomic.h>
28 
29 /*
30  * These are the void returning variants
31  */
32 /* BEGIN CSTYLED */
33 #define	ATOMIC_INC(name, type) \
34 	void atomic_inc_##name(volatile type *target)			\
35 	{								\
36 		(void) __atomic_add_fetch(target, 1, __ATOMIC_SEQ_CST);	\
37 	}
38 
39 ATOMIC_INC(8, uint8_t)
40 ATOMIC_INC(uchar, uchar_t)
41 ATOMIC_INC(16, uint16_t)
42 ATOMIC_INC(ushort, ushort_t)
43 ATOMIC_INC(32, uint32_t)
44 ATOMIC_INC(uint, uint_t)
45 ATOMIC_INC(ulong, ulong_t)
46 ATOMIC_INC(64, uint64_t)
47 
48 
49 #define	ATOMIC_DEC(name, type) \
50 	void atomic_dec_##name(volatile type *target)			\
51 	{								\
52 		(void) __atomic_sub_fetch(target, 1, __ATOMIC_SEQ_CST);	\
53 	}
54 
55 ATOMIC_DEC(8, uint8_t)
56 ATOMIC_DEC(uchar, uchar_t)
57 ATOMIC_DEC(16, uint16_t)
58 ATOMIC_DEC(ushort, ushort_t)
59 ATOMIC_DEC(32, uint32_t)
60 ATOMIC_DEC(uint, uint_t)
61 ATOMIC_DEC(ulong, ulong_t)
62 ATOMIC_DEC(64, uint64_t)
63 
64 
65 #define	ATOMIC_ADD(name, type1, type2) \
66 	void atomic_add_##name(volatile type1 *target, type2 bits)	\
67 	{								\
68 		(void) __atomic_add_fetch(target, bits, __ATOMIC_SEQ_CST); \
69 	}
70 
71 ATOMIC_ADD(8, uint8_t, int8_t)
72 ATOMIC_ADD(char, uchar_t, signed char)
73 ATOMIC_ADD(16, uint16_t, int16_t)
74 ATOMIC_ADD(short, ushort_t, short)
75 ATOMIC_ADD(32, uint32_t, int32_t)
76 ATOMIC_ADD(int, uint_t, int)
77 ATOMIC_ADD(long, ulong_t, long)
78 ATOMIC_ADD(64, uint64_t, int64_t)
79 
80 void
81 atomic_add_ptr(volatile void *target, ssize_t bits)
82 {
83 	(void) __atomic_add_fetch((void **)target, bits, __ATOMIC_SEQ_CST);
84 }
85 
86 
87 #define	ATOMIC_SUB(name, type1, type2) \
88 	void atomic_sub_##name(volatile type1 *target, type2 bits)	\
89 	{								\
90 		(void) __atomic_sub_fetch(target, bits, __ATOMIC_SEQ_CST); \
91 	}
92 
93 ATOMIC_SUB(8, uint8_t, int8_t)
94 ATOMIC_SUB(char, uchar_t, signed char)
95 ATOMIC_SUB(16, uint16_t, int16_t)
96 ATOMIC_SUB(short, ushort_t, short)
97 ATOMIC_SUB(32, uint32_t, int32_t)
98 ATOMIC_SUB(int, uint_t, int)
99 ATOMIC_SUB(long, ulong_t, long)
100 ATOMIC_SUB(64, uint64_t, int64_t)
101 
102 void
103 atomic_sub_ptr(volatile void *target, ssize_t bits)
104 {
105 	(void) __atomic_sub_fetch((void **)target, bits, __ATOMIC_SEQ_CST);
106 }
107 
108 
109 #define	ATOMIC_OR(name, type) \
110 	void atomic_or_##name(volatile type *target, type bits)		\
111 	{								\
112 		(void) __atomic_or_fetch(target, bits, __ATOMIC_SEQ_CST); \
113 	}
114 
115 ATOMIC_OR(8, uint8_t)
116 ATOMIC_OR(uchar, uchar_t)
117 ATOMIC_OR(16, uint16_t)
118 ATOMIC_OR(ushort, ushort_t)
119 ATOMIC_OR(32, uint32_t)
120 ATOMIC_OR(uint, uint_t)
121 ATOMIC_OR(ulong, ulong_t)
122 ATOMIC_OR(64, uint64_t)
123 
124 
125 #define	ATOMIC_AND(name, type) \
126 	void atomic_and_##name(volatile type *target, type bits)	\
127 	{								\
128 		(void) __atomic_and_fetch(target, bits, __ATOMIC_SEQ_CST); \
129 	}
130 
131 ATOMIC_AND(8, uint8_t)
132 ATOMIC_AND(uchar, uchar_t)
133 ATOMIC_AND(16, uint16_t)
134 ATOMIC_AND(ushort, ushort_t)
135 ATOMIC_AND(32, uint32_t)
136 ATOMIC_AND(uint, uint_t)
137 ATOMIC_AND(ulong, ulong_t)
138 ATOMIC_AND(64, uint64_t)
139 
140 
141 /*
142  * New value returning variants
143  */
144 
145 #define	ATOMIC_INC_NV(name, type) \
146 	type atomic_inc_##name##_nv(volatile type *target)		\
147 	{								\
148 		return (__atomic_add_fetch(target, 1, __ATOMIC_SEQ_CST)); \
149 	}
150 
151 ATOMIC_INC_NV(8, uint8_t)
152 ATOMIC_INC_NV(uchar, uchar_t)
153 ATOMIC_INC_NV(16, uint16_t)
154 ATOMIC_INC_NV(ushort, ushort_t)
155 ATOMIC_INC_NV(32, uint32_t)
156 ATOMIC_INC_NV(uint, uint_t)
157 ATOMIC_INC_NV(ulong, ulong_t)
158 ATOMIC_INC_NV(64, uint64_t)
159 
160 
161 #define	ATOMIC_DEC_NV(name, type) \
162 	type atomic_dec_##name##_nv(volatile type *target)		\
163 	{								\
164 		return (__atomic_sub_fetch(target, 1, __ATOMIC_SEQ_CST)); \
165 	}
166 
167 ATOMIC_DEC_NV(8, uint8_t)
168 ATOMIC_DEC_NV(uchar, uchar_t)
169 ATOMIC_DEC_NV(16, uint16_t)
170 ATOMIC_DEC_NV(ushort, ushort_t)
171 ATOMIC_DEC_NV(32, uint32_t)
172 ATOMIC_DEC_NV(uint, uint_t)
173 ATOMIC_DEC_NV(ulong, ulong_t)
174 ATOMIC_DEC_NV(64, uint64_t)
175 
176 
177 #define	ATOMIC_ADD_NV(name, type1, type2) \
178 	type1 atomic_add_##name##_nv(volatile type1 *target, type2 bits) \
179 	{								\
180 		return (__atomic_add_fetch(target, bits, __ATOMIC_SEQ_CST)); \
181 	}
182 
183 ATOMIC_ADD_NV(8, uint8_t, int8_t)
184 ATOMIC_ADD_NV(char, uchar_t, signed char)
185 ATOMIC_ADD_NV(16, uint16_t, int16_t)
186 ATOMIC_ADD_NV(short, ushort_t, short)
187 ATOMIC_ADD_NV(32, uint32_t, int32_t)
188 ATOMIC_ADD_NV(int, uint_t, int)
189 ATOMIC_ADD_NV(long, ulong_t, long)
190 ATOMIC_ADD_NV(64, uint64_t, int64_t)
191 
192 void *
193 atomic_add_ptr_nv(volatile void *target, ssize_t bits)
194 {
195 	return (__atomic_add_fetch((void **)target, bits, __ATOMIC_SEQ_CST));
196 }
197 
198 
199 #define	ATOMIC_SUB_NV(name, type1, type2) \
200 	type1 atomic_sub_##name##_nv(volatile type1 *target, type2 bits) \
201 	{								\
202 		return (__atomic_sub_fetch(target, bits, __ATOMIC_SEQ_CST)); \
203 	}
204 
205 ATOMIC_SUB_NV(8, uint8_t, int8_t)
206 ATOMIC_SUB_NV(char, uchar_t, signed char)
207 ATOMIC_SUB_NV(16, uint16_t, int16_t)
208 ATOMIC_SUB_NV(short, ushort_t, short)
209 ATOMIC_SUB_NV(32, uint32_t, int32_t)
210 ATOMIC_SUB_NV(int, uint_t, int)
211 ATOMIC_SUB_NV(long, ulong_t, long)
212 ATOMIC_SUB_NV(64, uint64_t, int64_t)
213 
214 void *
215 atomic_sub_ptr_nv(volatile void *target, ssize_t bits)
216 {
217 	return (__atomic_sub_fetch((void **)target, bits, __ATOMIC_SEQ_CST));
218 }
219 
220 
221 #define	ATOMIC_OR_NV(name, type) \
222 	type atomic_or_##name##_nv(volatile type *target, type bits)	\
223 	{								\
224 		return (__atomic_or_fetch(target, bits, __ATOMIC_SEQ_CST)); \
225 	}
226 
227 ATOMIC_OR_NV(8, uint8_t)
228 ATOMIC_OR_NV(uchar, uchar_t)
229 ATOMIC_OR_NV(16, uint16_t)
230 ATOMIC_OR_NV(ushort, ushort_t)
231 ATOMIC_OR_NV(32, uint32_t)
232 ATOMIC_OR_NV(uint, uint_t)
233 ATOMIC_OR_NV(ulong, ulong_t)
234 ATOMIC_OR_NV(64, uint64_t)
235 
236 
237 #define	ATOMIC_AND_NV(name, type) \
238 	type atomic_and_##name##_nv(volatile type *target, type bits)	\
239 	{								\
240 		return (__atomic_and_fetch(target, bits, __ATOMIC_SEQ_CST)); \
241 	}
242 
243 ATOMIC_AND_NV(8, uint8_t)
244 ATOMIC_AND_NV(uchar, uchar_t)
245 ATOMIC_AND_NV(16, uint16_t)
246 ATOMIC_AND_NV(ushort, ushort_t)
247 ATOMIC_AND_NV(32, uint32_t)
248 ATOMIC_AND_NV(uint, uint_t)
249 ATOMIC_AND_NV(ulong, ulong_t)
250 ATOMIC_AND_NV(64, uint64_t)
251 
252 
253 /*
254  * If *tgt == exp, set *tgt = des; return old value
255  *
256  * This may not look right on the first pass (or the sixteenth), but,
257  * from https://gcc.gnu.org/onlinedocs/gcc/_005f_005fatomic-Builtins.html:
258  * > If they are not equal, the operation is a read
259  * > and the current contents of *ptr are written into *expected.
260  * And, in the converse case, exp is already *target by definition.
261  */
262 
263 #define	ATOMIC_CAS(name, type) \
264 	type atomic_cas_##name(volatile type *target, type exp, type des) \
265 	{								\
266 		__atomic_compare_exchange_n(target, &exp, des, B_FALSE,	\
267 		    __ATOMIC_SEQ_CST, __ATOMIC_SEQ_CST);		\
268 		return (exp);						\
269 	}
270 
271 ATOMIC_CAS(8, uint8_t)
272 ATOMIC_CAS(uchar, uchar_t)
273 ATOMIC_CAS(16, uint16_t)
274 ATOMIC_CAS(ushort, ushort_t)
275 ATOMIC_CAS(32, uint32_t)
276 ATOMIC_CAS(uint, uint_t)
277 ATOMIC_CAS(ulong, ulong_t)
278 ATOMIC_CAS(64, uint64_t)
279 
280 void *
281 atomic_cas_ptr(volatile void *target, void *exp, void *des)
282 {
283 
284 	__atomic_compare_exchange_n((void **)target, &exp, des, B_FALSE,
285 	    __ATOMIC_SEQ_CST, __ATOMIC_SEQ_CST);
286 	return (exp);
287 }
288 
289 
290 /*
291  * Swap target and return old value
292  */
293 
294 #define	ATOMIC_SWAP(name, type) \
295 	type atomic_swap_##name(volatile type *target, type bits)	\
296 	{								\
297 		return (__atomic_exchange_n(target, bits, __ATOMIC_SEQ_CST)); \
298 	}
299 
300 ATOMIC_SWAP(8, uint8_t)
301 ATOMIC_SWAP(uchar, uchar_t)
302 ATOMIC_SWAP(16, uint16_t)
303 ATOMIC_SWAP(ushort, ushort_t)
304 ATOMIC_SWAP(32, uint32_t)
305 ATOMIC_SWAP(uint, uint_t)
306 ATOMIC_SWAP(ulong, ulong_t)
307 ATOMIC_SWAP(64, uint64_t)
308 /* END CSTYLED */
309 
310 void *
311 atomic_swap_ptr(volatile void *target, void *bits)
312 {
313 	return (__atomic_exchange_n((void **)target, bits, __ATOMIC_SEQ_CST));
314 }
315 
316 #ifndef _LP64
317 uint64_t
318 atomic_load_64(volatile uint64_t *target)
319 {
320 	return (__atomic_load_n(target, __ATOMIC_RELAXED));
321 }
322 
323 void
324 atomic_store_64(volatile uint64_t *target, uint64_t bits)
325 {
326 	return (__atomic_store_n(target, bits, __ATOMIC_RELAXED));
327 }
328 #endif
329 
330 int
331 atomic_set_long_excl(volatile ulong_t *target, uint_t value)
332 {
333 	ulong_t bit = 1UL << value;
334 	ulong_t old = __atomic_fetch_or(target, bit, __ATOMIC_SEQ_CST);
335 	return ((old & bit) ? -1 : 0);
336 }
337 
338 int
339 atomic_clear_long_excl(volatile ulong_t *target, uint_t value)
340 {
341 	ulong_t bit = 1UL << value;
342 	ulong_t old = __atomic_fetch_and(target, ~bit, __ATOMIC_SEQ_CST);
343 	return ((old & bit) ? 0 : -1);
344 }
345 
346 void
347 membar_enter(void)
348 {
349 	__atomic_thread_fence(__ATOMIC_SEQ_CST);
350 }
351 
352 void
353 membar_exit(void)
354 {
355 	__atomic_thread_fence(__ATOMIC_SEQ_CST);
356 }
357 
358 void
359 membar_producer(void)
360 {
361 	__atomic_thread_fence(__ATOMIC_RELEASE);
362 }
363 
364 void
365 membar_consumer(void)
366 {
367 	__atomic_thread_fence(__ATOMIC_ACQUIRE);
368 }
369