1 /*-
2 * Copyright (c) 2010 Isilon Systems, Inc.
3 * Copyright (c) 2010 iX Systems, Inc.
4 * Copyright (c) 2010 Panasas, Inc.
5 * Copyright (c) 2013-2018 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
32 #ifndef _LINUXKPI_ASM_ATOMIC_H_
33 #define _LINUXKPI_ASM_ATOMIC_H_
34
35 #include <linux/compiler.h>
36 #include <sys/types.h>
37 #include <machine/atomic.h>
38 #define ATOMIC_INIT(x) { .counter = (x) }
39
40 typedef struct {
41 volatile int counter;
42 } atomic_t;
43
44 /*------------------------------------------------------------------------*
45 * 32-bit atomic operations
46 *------------------------------------------------------------------------*/
47
48 #define atomic_add(i, v) atomic_add_return((i), (v))
49 #define atomic_sub(i, v) atomic_sub_return((i), (v))
50 #define atomic_inc_return(v) atomic_add_return(1, (v))
51 #define atomic_add_negative(i, v) (atomic_add_return((i), (v)) < 0)
52 #define atomic_add_and_test(i, v) (atomic_add_return((i), (v)) == 0)
53 #define atomic_sub_and_test(i, v) (atomic_sub_return((i), (v)) == 0)
54 #define atomic_dec_and_test(v) (atomic_sub_return(1, (v)) == 0)
55 #define atomic_inc_and_test(v) (atomic_add_return(1, (v)) == 0)
56 #define atomic_dec_return(v) atomic_sub_return(1, (v))
57 #define atomic_inc_not_zero(v) atomic_add_unless((v), 1, 0)
58
59 static inline int
atomic_add_return(int i,atomic_t * v)60 atomic_add_return(int i, atomic_t *v)
61 {
62 return i + atomic_fetchadd_int(&v->counter, i);
63 }
64
65 static inline int
atomic_sub_return(int i,atomic_t * v)66 atomic_sub_return(int i, atomic_t *v)
67 {
68 return atomic_fetchadd_int(&v->counter, -i) - i;
69 }
70
71 static inline void
atomic_set(atomic_t * v,int i)72 atomic_set(atomic_t *v, int i)
73 {
74 WRITE_ONCE(v->counter, i);
75 }
76
77 static inline void
atomic_set_release(atomic_t * v,int i)78 atomic_set_release(atomic_t *v, int i)
79 {
80 atomic_store_rel_int(&v->counter, i);
81 }
82
83 static inline void
atomic_set_mask(unsigned int mask,atomic_t * v)84 atomic_set_mask(unsigned int mask, atomic_t *v)
85 {
86 atomic_set_int(&v->counter, mask);
87 }
88
89 static inline int
atomic_read(const atomic_t * v)90 atomic_read(const atomic_t *v)
91 {
92 return READ_ONCE(v->counter);
93 }
94
95 static inline int
atomic_inc(atomic_t * v)96 atomic_inc(atomic_t *v)
97 {
98 return atomic_fetchadd_int(&v->counter, 1) + 1;
99 }
100
101 static inline int
atomic_dec(atomic_t * v)102 atomic_dec(atomic_t *v)
103 {
104 return atomic_fetchadd_int(&v->counter, -1) - 1;
105 }
106
107 static inline int
atomic_add_unless(atomic_t * v,int a,int u)108 atomic_add_unless(atomic_t *v, int a, int u)
109 {
110 int c = atomic_read(v);
111
112 for (;;) {
113 if (unlikely(c == u))
114 break;
115 if (likely(atomic_fcmpset_int(&v->counter, &c, c + a)))
116 break;
117 }
118 return (c != u);
119 }
120
121 static inline int
atomic_fetch_add_unless(atomic_t * v,int a,int u)122 atomic_fetch_add_unless(atomic_t *v, int a, int u)
123 {
124 int c = atomic_read(v);
125
126 for (;;) {
127 if (unlikely(c == u))
128 break;
129 if (likely(atomic_fcmpset_int(&v->counter, &c, c + a)))
130 break;
131 }
132 return (c);
133 }
134
135 static inline void
atomic_clear_mask(unsigned int mask,atomic_t * v)136 atomic_clear_mask(unsigned int mask, atomic_t *v)
137 {
138 atomic_clear_int(&v->counter, mask);
139 }
140
141 static inline int
atomic_xchg(atomic_t * v,int i)142 atomic_xchg(atomic_t *v, int i)
143 {
144 return (atomic_swap_int(&v->counter, i));
145 }
146
147 static inline int
atomic_cmpxchg(atomic_t * v,int old,int new)148 atomic_cmpxchg(atomic_t *v, int old, int new)
149 {
150 int ret = old;
151
152 for (;;) {
153 if (atomic_fcmpset_int(&v->counter, &ret, new))
154 break;
155 if (ret != old)
156 break;
157 }
158 return (ret);
159 }
160
161 #if defined(__amd64__) || defined(__arm64__) || defined(__i386__)
162 #define LINUXKPI_ATOMIC_8(...) __VA_ARGS__
163 #define LINUXKPI_ATOMIC_16(...) __VA_ARGS__
164 #else
165 #define LINUXKPI_ATOMIC_8(...)
166 #define LINUXKPI_ATOMIC_16(...)
167 #endif
168
169 #if !(defined(i386) || (defined(__mips__) && !(defined(__mips_n32) || \
170 defined(__mips_n64))) || (defined(__powerpc__) && \
171 !defined(__powerpc64__)))
172 #define LINUXKPI_ATOMIC_64(...) __VA_ARGS__
173 #else
174 #define LINUXKPI_ATOMIC_64(...)
175 #endif
176
177 #define cmpxchg(ptr, old, new) ({ \
178 union { \
179 __typeof(*(ptr)) val; \
180 u8 u8[0]; \
181 u16 u16[0]; \
182 u32 u32[0]; \
183 u64 u64[0]; \
184 } __ret = { .val = (old) }, __new = { .val = (new) }; \
185 \
186 CTASSERT( \
187 LINUXKPI_ATOMIC_8(sizeof(__ret.val) == 1 ||) \
188 LINUXKPI_ATOMIC_16(sizeof(__ret.val) == 2 ||) \
189 LINUXKPI_ATOMIC_64(sizeof(__ret.val) == 8 ||) \
190 sizeof(__ret.val) == 4); \
191 \
192 switch (sizeof(__ret.val)) { \
193 LINUXKPI_ATOMIC_8( \
194 case 1: \
195 while (!atomic_fcmpset_8((volatile u8 *)(ptr), \
196 __ret.u8, __new.u8[0]) && __ret.val == (old)) \
197 ; \
198 break; \
199 ) \
200 LINUXKPI_ATOMIC_16( \
201 case 2: \
202 while (!atomic_fcmpset_16((volatile u16 *)(ptr), \
203 __ret.u16, __new.u16[0]) && __ret.val == (old)) \
204 ; \
205 break; \
206 ) \
207 case 4: \
208 while (!atomic_fcmpset_32((volatile u32 *)(ptr), \
209 __ret.u32, __new.u32[0]) && __ret.val == (old)) \
210 ; \
211 break; \
212 LINUXKPI_ATOMIC_64( \
213 case 8: \
214 while (!atomic_fcmpset_64((volatile u64 *)(ptr), \
215 __ret.u64, __new.u64[0]) && __ret.val == (old)) \
216 ; \
217 break; \
218 ) \
219 } \
220 __ret.val; \
221 })
222
223 #define cmpxchg_relaxed(...) cmpxchg(__VA_ARGS__)
224
225 #define xchg(ptr, new) ({ \
226 union { \
227 __typeof(*(ptr)) val; \
228 u8 u8[0]; \
229 u16 u16[0]; \
230 u32 u32[0]; \
231 u64 u64[0]; \
232 } __ret, __new = { .val = (new) }; \
233 \
234 CTASSERT( \
235 LINUXKPI_ATOMIC_8(sizeof(__ret.val) == 1 ||) \
236 LINUXKPI_ATOMIC_16(sizeof(__ret.val) == 2 ||) \
237 LINUXKPI_ATOMIC_64(sizeof(__ret.val) == 8 ||) \
238 sizeof(__ret.val) == 4); \
239 \
240 switch (sizeof(__ret.val)) { \
241 LINUXKPI_ATOMIC_8( \
242 case 1: \
243 __ret.val = READ_ONCE(*ptr); \
244 while (!atomic_fcmpset_8((volatile u8 *)(ptr), \
245 __ret.u8, __new.u8[0])) \
246 ; \
247 break; \
248 ) \
249 LINUXKPI_ATOMIC_16( \
250 case 2: \
251 __ret.val = READ_ONCE(*ptr); \
252 while (!atomic_fcmpset_16((volatile u16 *)(ptr), \
253 __ret.u16, __new.u16[0])) \
254 ; \
255 break; \
256 ) \
257 case 4: \
258 __ret.u32[0] = atomic_swap_32((volatile u32 *)(ptr), \
259 __new.u32[0]); \
260 break; \
261 LINUXKPI_ATOMIC_64( \
262 case 8: \
263 __ret.u64[0] = atomic_swap_64((volatile u64 *)(ptr), \
264 __new.u64[0]); \
265 break; \
266 ) \
267 } \
268 __ret.val; \
269 })
270
271 static inline int
atomic_dec_if_positive(atomic_t * v)272 atomic_dec_if_positive(atomic_t *v)
273 {
274 int retval;
275 int old;
276
277 old = atomic_read(v);
278 for (;;) {
279 retval = old - 1;
280 if (unlikely(retval < 0))
281 break;
282 if (likely(atomic_fcmpset_int(&v->counter, &old, retval)))
283 break;
284 }
285 return (retval);
286 }
287
288 #define LINUX_ATOMIC_OP(op, c_op) \
289 static inline void atomic_##op(int i, atomic_t *v) \
290 { \
291 int c, old; \
292 \
293 c = v->counter; \
294 while ((old = atomic_cmpxchg(v, c, c c_op i)) != c) \
295 c = old; \
296 }
297
298 #define LINUX_ATOMIC_FETCH_OP(op, c_op) \
299 static inline int atomic_fetch_##op(int i, atomic_t *v) \
300 { \
301 int c, old; \
302 \
303 c = v->counter; \
304 while ((old = atomic_cmpxchg(v, c, c c_op i)) != c) \
305 c = old; \
306 \
307 return (c); \
308 }
309
310 LINUX_ATOMIC_OP(or, |)
311 LINUX_ATOMIC_OP(and, &)
312 LINUX_ATOMIC_OP(andnot, &~)
313 LINUX_ATOMIC_OP(xor, ^)
314
315 LINUX_ATOMIC_FETCH_OP(or, |)
316 LINUX_ATOMIC_FETCH_OP(and, &)
317 LINUX_ATOMIC_FETCH_OP(andnot, &~)
318 LINUX_ATOMIC_FETCH_OP(xor, ^)
319
320 #endif /* _LINUXKPI_ASM_ATOMIC_H_ */
321