xref: /freebsd/sys/contrib/openzfs/lib/libspl/atomic.c (revision b64c5a0ace59af62eff52bfe110a521dc73c937b)
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 https://opensource.org/licenses/CDDL-1.0.
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 #define	ATOMIC_INC(name, type) \
33 	void atomic_inc_##name(volatile type *target)			\
34 	{								\
35 		(void) __atomic_add_fetch(target, 1, __ATOMIC_SEQ_CST);	\
36 	}
37 
38 ATOMIC_INC(8, uint8_t)
39 ATOMIC_INC(16, uint16_t)
40 ATOMIC_INC(32, uint32_t)
41 ATOMIC_INC(64, uint64_t)
42 ATOMIC_INC(uchar, uchar_t)
43 ATOMIC_INC(ushort, ushort_t)
44 ATOMIC_INC(uint, uint_t)
45 ATOMIC_INC(ulong, ulong_t)
46 
47 
48 #define	ATOMIC_DEC(name, type) \
49 	void atomic_dec_##name(volatile type *target)			\
50 	{								\
51 		(void) __atomic_sub_fetch(target, 1, __ATOMIC_SEQ_CST);	\
52 	}
53 
54 ATOMIC_DEC(8, uint8_t)
55 ATOMIC_DEC(16, uint16_t)
56 ATOMIC_DEC(32, uint32_t)
57 ATOMIC_DEC(64, uint64_t)
58 ATOMIC_DEC(uchar, uchar_t)
59 ATOMIC_DEC(ushort, ushort_t)
60 ATOMIC_DEC(uint, uint_t)
61 ATOMIC_DEC(ulong, ulong_t)
62 
63 
64 #define	ATOMIC_ADD(name, type1, type2) \
65 	void atomic_add_##name(volatile type1 *target, type2 bits)	\
66 	{								\
67 		(void) __atomic_add_fetch(target, bits, __ATOMIC_SEQ_CST); \
68 	}
69 
70 void
71 atomic_add_ptr(volatile void *target, ssize_t bits)
72 {
73 	(void) __atomic_add_fetch((void **)target, bits, __ATOMIC_SEQ_CST);
74 }
75 
76 ATOMIC_ADD(8, uint8_t, int8_t)
77 ATOMIC_ADD(16, uint16_t, int16_t)
78 ATOMIC_ADD(32, uint32_t, int32_t)
79 ATOMIC_ADD(64, uint64_t, int64_t)
80 ATOMIC_ADD(char, uchar_t, signed char)
81 ATOMIC_ADD(short, ushort_t, short)
82 ATOMIC_ADD(int, uint_t, int)
83 ATOMIC_ADD(long, ulong_t, long)
84 
85 
86 #define	ATOMIC_SUB(name, type1, type2) \
87 	void atomic_sub_##name(volatile type1 *target, type2 bits)	\
88 	{								\
89 		(void) __atomic_sub_fetch(target, bits, __ATOMIC_SEQ_CST); \
90 	}
91 
92 void
93 atomic_sub_ptr(volatile void *target, ssize_t bits)
94 {
95 	(void) __atomic_sub_fetch((void **)target, bits, __ATOMIC_SEQ_CST);
96 }
97 
98 ATOMIC_SUB(8, uint8_t, int8_t)
99 ATOMIC_SUB(16, uint16_t, int16_t)
100 ATOMIC_SUB(32, uint32_t, int32_t)
101 ATOMIC_SUB(64, uint64_t, int64_t)
102 ATOMIC_SUB(char, uchar_t, signed char)
103 ATOMIC_SUB(short, ushort_t, short)
104 ATOMIC_SUB(int, uint_t, int)
105 ATOMIC_SUB(long, ulong_t, long)
106 
107 
108 #define	ATOMIC_OR(name, type) \
109 	void atomic_or_##name(volatile type *target, type bits)		\
110 	{								\
111 		(void) __atomic_or_fetch(target, bits, __ATOMIC_SEQ_CST); \
112 	}
113 
114 ATOMIC_OR(8, uint8_t)
115 ATOMIC_OR(16, uint16_t)
116 ATOMIC_OR(32, uint32_t)
117 ATOMIC_OR(64, uint64_t)
118 ATOMIC_OR(uchar, uchar_t)
119 ATOMIC_OR(ushort, ushort_t)
120 ATOMIC_OR(uint, uint_t)
121 ATOMIC_OR(ulong, ulong_t)
122 
123 
124 #define	ATOMIC_AND(name, type) \
125 	void atomic_and_##name(volatile type *target, type bits)	\
126 	{								\
127 		(void) __atomic_and_fetch(target, bits, __ATOMIC_SEQ_CST); \
128 	}
129 
130 ATOMIC_AND(8, uint8_t)
131 ATOMIC_AND(16, uint16_t)
132 ATOMIC_AND(32, uint32_t)
133 ATOMIC_AND(64, uint64_t)
134 ATOMIC_AND(uchar, uchar_t)
135 ATOMIC_AND(ushort, ushort_t)
136 ATOMIC_AND(uint, uint_t)
137 ATOMIC_AND(ulong, ulong_t)
138 
139 
140 /*
141  * New value returning variants
142  */
143 
144 #define	ATOMIC_INC_NV(name, type) \
145 	type atomic_inc_##name##_nv(volatile type *target)		\
146 	{								\
147 		return (__atomic_add_fetch(target, 1, __ATOMIC_SEQ_CST)); \
148 	}
149 
150 ATOMIC_INC_NV(8, uint8_t)
151 ATOMIC_INC_NV(16, uint16_t)
152 ATOMIC_INC_NV(32, uint32_t)
153 ATOMIC_INC_NV(64, uint64_t)
154 ATOMIC_INC_NV(uchar, uchar_t)
155 ATOMIC_INC_NV(ushort, ushort_t)
156 ATOMIC_INC_NV(uint, uint_t)
157 ATOMIC_INC_NV(ulong, ulong_t)
158 
159 
160 #define	ATOMIC_DEC_NV(name, type) \
161 	type atomic_dec_##name##_nv(volatile type *target)		\
162 	{								\
163 		return (__atomic_sub_fetch(target, 1, __ATOMIC_SEQ_CST)); \
164 	}
165 
166 ATOMIC_DEC_NV(8, uint8_t)
167 ATOMIC_DEC_NV(16, uint16_t)
168 ATOMIC_DEC_NV(32, uint32_t)
169 ATOMIC_DEC_NV(64, uint64_t)
170 ATOMIC_DEC_NV(uchar, uchar_t)
171 ATOMIC_DEC_NV(ushort, ushort_t)
172 ATOMIC_DEC_NV(uint, uint_t)
173 ATOMIC_DEC_NV(ulong, ulong_t)
174 
175 
176 #define	ATOMIC_ADD_NV(name, type1, type2) \
177 	type1 atomic_add_##name##_nv(volatile type1 *target, type2 bits) \
178 	{								\
179 		return (__atomic_add_fetch(target, bits, __ATOMIC_SEQ_CST)); \
180 	}
181 
182 void *
183 atomic_add_ptr_nv(volatile void *target, ssize_t bits)
184 {
185 	return (__atomic_add_fetch((void **)target, bits, __ATOMIC_SEQ_CST));
186 }
187 
188 ATOMIC_ADD_NV(8, uint8_t, int8_t)
189 ATOMIC_ADD_NV(16, uint16_t, int16_t)
190 ATOMIC_ADD_NV(32, uint32_t, int32_t)
191 ATOMIC_ADD_NV(64, uint64_t, int64_t)
192 ATOMIC_ADD_NV(char, uchar_t, signed char)
193 ATOMIC_ADD_NV(short, ushort_t, short)
194 ATOMIC_ADD_NV(int, uint_t, int)
195 ATOMIC_ADD_NV(long, ulong_t, long)
196 
197 
198 #define	ATOMIC_SUB_NV(name, type1, type2) \
199 	type1 atomic_sub_##name##_nv(volatile type1 *target, type2 bits) \
200 	{								\
201 		return (__atomic_sub_fetch(target, bits, __ATOMIC_SEQ_CST)); \
202 	}
203 
204 void *
205 atomic_sub_ptr_nv(volatile void *target, ssize_t bits)
206 {
207 	return (__atomic_sub_fetch((void **)target, bits, __ATOMIC_SEQ_CST));
208 }
209 
210 ATOMIC_SUB_NV(8, uint8_t, int8_t)
211 ATOMIC_SUB_NV(char, uchar_t, signed char)
212 ATOMIC_SUB_NV(16, uint16_t, int16_t)
213 ATOMIC_SUB_NV(short, ushort_t, short)
214 ATOMIC_SUB_NV(32, uint32_t, int32_t)
215 ATOMIC_SUB_NV(int, uint_t, int)
216 ATOMIC_SUB_NV(long, ulong_t, long)
217 ATOMIC_SUB_NV(64, uint64_t, int64_t)
218 
219 
220 #define	ATOMIC_OR_NV(name, type) \
221 	type atomic_or_##name##_nv(volatile type *target, type bits)	\
222 	{								\
223 		return (__atomic_or_fetch(target, bits, __ATOMIC_SEQ_CST)); \
224 	}
225 
226 ATOMIC_OR_NV(8, uint8_t)
227 ATOMIC_OR_NV(16, uint16_t)
228 ATOMIC_OR_NV(32, uint32_t)
229 ATOMIC_OR_NV(64, uint64_t)
230 ATOMIC_OR_NV(uchar, uchar_t)
231 ATOMIC_OR_NV(ushort, ushort_t)
232 ATOMIC_OR_NV(uint, uint_t)
233 ATOMIC_OR_NV(ulong, ulong_t)
234 
235 
236 #define	ATOMIC_AND_NV(name, type) \
237 	type atomic_and_##name##_nv(volatile type *target, type bits)	\
238 	{								\
239 		return (__atomic_and_fetch(target, bits, __ATOMIC_SEQ_CST)); \
240 	}
241 
242 ATOMIC_AND_NV(8, uint8_t)
243 ATOMIC_AND_NV(16, uint16_t)
244 ATOMIC_AND_NV(32, uint32_t)
245 ATOMIC_AND_NV(64, uint64_t)
246 ATOMIC_AND_NV(uchar, uchar_t)
247 ATOMIC_AND_NV(ushort, ushort_t)
248 ATOMIC_AND_NV(uint, uint_t)
249 ATOMIC_AND_NV(ulong, ulong_t)
250 
251 
252 /*
253  * If *tgt == exp, set *tgt = des; return old value
254  *
255  * This may not look right on the first pass (or the sixteenth), but,
256  * from https://gcc.gnu.org/onlinedocs/gcc/_005f_005fatomic-Builtins.html:
257  * > If they are not equal, the operation is a read
258  * > and the current contents of *ptr are written into *expected.
259  * And, in the converse case, exp is already *target by definition.
260  */
261 
262 #define	ATOMIC_CAS(name, type) \
263 	type atomic_cas_##name(volatile type *target, type exp, type des) \
264 	{								\
265 		__atomic_compare_exchange_n(target, &exp, des, B_FALSE,	\
266 		    __ATOMIC_SEQ_CST, __ATOMIC_SEQ_CST);		\
267 		return (exp);						\
268 	}
269 
270 void *
271 atomic_cas_ptr(volatile void *target, void *exp, void *des)
272 {
273 
274 	__atomic_compare_exchange_n((void **)target, &exp, des, B_FALSE,
275 	    __ATOMIC_SEQ_CST, __ATOMIC_SEQ_CST);
276 	return (exp);
277 }
278 
279 ATOMIC_CAS(8, uint8_t)
280 ATOMIC_CAS(16, uint16_t)
281 ATOMIC_CAS(32, uint32_t)
282 ATOMIC_CAS(64, uint64_t)
283 ATOMIC_CAS(uchar, uchar_t)
284 ATOMIC_CAS(ushort, ushort_t)
285 ATOMIC_CAS(uint, uint_t)
286 ATOMIC_CAS(ulong, ulong_t)
287 
288 
289 /*
290  * Swap target and return old value
291  */
292 
293 #define	ATOMIC_SWAP(name, type) \
294 	type atomic_swap_##name(volatile type *target, type bits)	\
295 	{								\
296 		return (__atomic_exchange_n(target, bits, __ATOMIC_SEQ_CST)); \
297 	}
298 
299 ATOMIC_SWAP(8, uint8_t)
300 ATOMIC_SWAP(16, uint16_t)
301 ATOMIC_SWAP(32, uint32_t)
302 ATOMIC_SWAP(64, uint64_t)
303 ATOMIC_SWAP(uchar, uchar_t)
304 ATOMIC_SWAP(ushort, ushort_t)
305 ATOMIC_SWAP(uint, uint_t)
306 ATOMIC_SWAP(ulong, ulong_t)
307 
308 void *
309 atomic_swap_ptr(volatile void *target, void *bits)
310 {
311 	return (__atomic_exchange_n((void **)target, bits, __ATOMIC_SEQ_CST));
312 }
313 
314 #ifndef _LP64
315 uint64_t
316 atomic_load_64(volatile uint64_t *target)
317 {
318 	return (__atomic_load_n(target, __ATOMIC_RELAXED));
319 }
320 
321 void
322 atomic_store_64(volatile uint64_t *target, uint64_t bits)
323 {
324 	return (__atomic_store_n(target, bits, __ATOMIC_RELAXED));
325 }
326 #endif
327 
328 int
329 atomic_set_long_excl(volatile ulong_t *target, uint_t value)
330 {
331 	ulong_t bit = 1UL << value;
332 	ulong_t old = __atomic_fetch_or(target, bit, __ATOMIC_SEQ_CST);
333 	return ((old & bit) ? -1 : 0);
334 }
335 
336 int
337 atomic_clear_long_excl(volatile ulong_t *target, uint_t value)
338 {
339 	ulong_t bit = 1UL << value;
340 	ulong_t old = __atomic_fetch_and(target, ~bit, __ATOMIC_SEQ_CST);
341 	return ((old & bit) ? 0 : -1);
342 }
343 
344 void
345 membar_enter(void)
346 {
347 	__atomic_thread_fence(__ATOMIC_SEQ_CST);
348 }
349 
350 void
351 membar_exit(void)
352 {
353 	__atomic_thread_fence(__ATOMIC_SEQ_CST);
354 }
355 
356 void
357 membar_sync(void)
358 {
359 	__atomic_thread_fence(__ATOMIC_SEQ_CST);
360 }
361 
362 void
363 membar_producer(void)
364 {
365 	__atomic_thread_fence(__ATOMIC_RELEASE);
366 }
367 
368 void
369 membar_consumer(void)
370 {
371 	__atomic_thread_fence(__ATOMIC_ACQUIRE);
372 }
373