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
30 #ifndef _LINUXKPI_ASM_ATOMIC_H_
31 #define _LINUXKPI_ASM_ATOMIC_H_
32
33 #include <linux/compiler.h>
34 #include <sys/types.h>
35 #include <machine/atomic.h>
36 #define ATOMIC_INIT(x) { .counter = (x) }
37
38 typedef struct {
39 volatile int counter;
40 } atomic_t;
41
42 /*------------------------------------------------------------------------*
43 * 32-bit atomic operations
44 *------------------------------------------------------------------------*/
45
46 #define atomic_add(i, v) atomic_add_return((i), (v))
47 #define atomic_sub(i, v) atomic_sub_return((i), (v))
48 #define atomic_inc_return(v) atomic_add_return(1, (v))
49 #define atomic_add_negative(i, v) (atomic_add_return((i), (v)) < 0)
50 #define atomic_add_and_test(i, v) (atomic_add_return((i), (v)) == 0)
51 #define atomic_sub_and_test(i, v) (atomic_sub_return((i), (v)) == 0)
52 #define atomic_dec_and_test(v) (atomic_sub_return(1, (v)) == 0)
53 #define atomic_inc_and_test(v) (atomic_add_return(1, (v)) == 0)
54 #define atomic_dec_return(v) atomic_sub_return(1, (v))
55 #define atomic_inc_not_zero(v) atomic_add_unless((v), 1, 0)
56
57 static inline int
atomic_add_return(int i,atomic_t * v)58 atomic_add_return(int i, atomic_t *v)
59 {
60 return i + atomic_fetchadd_int(&v->counter, i);
61 }
62
63 static inline int
atomic_sub_return(int i,atomic_t * v)64 atomic_sub_return(int i, atomic_t *v)
65 {
66 return atomic_fetchadd_int(&v->counter, -i) - i;
67 }
68
69 static inline void
atomic_set(atomic_t * v,int i)70 atomic_set(atomic_t *v, int i)
71 {
72 WRITE_ONCE(v->counter, i);
73 }
74
75 static inline void
atomic_set_release(atomic_t * v,int i)76 atomic_set_release(atomic_t *v, int i)
77 {
78 atomic_store_rel_int(&v->counter, i);
79 }
80
81 static inline void
atomic_set_mask(unsigned int mask,atomic_t * v)82 atomic_set_mask(unsigned int mask, atomic_t *v)
83 {
84 atomic_set_int(&v->counter, mask);
85 }
86
87 static inline int
atomic_read(const atomic_t * v)88 atomic_read(const atomic_t *v)
89 {
90 return READ_ONCE(v->counter);
91 }
92
93 static inline int
atomic_inc(atomic_t * v)94 atomic_inc(atomic_t *v)
95 {
96 return atomic_fetchadd_int(&v->counter, 1) + 1;
97 }
98
99 static inline int
atomic_dec(atomic_t * v)100 atomic_dec(atomic_t *v)
101 {
102 return atomic_fetchadd_int(&v->counter, -1) - 1;
103 }
104
105 static inline int
atomic_add_unless(atomic_t * v,int a,int u)106 atomic_add_unless(atomic_t *v, int a, int u)
107 {
108 int c = atomic_read(v);
109
110 for (;;) {
111 if (unlikely(c == u))
112 break;
113 if (likely(atomic_fcmpset_int(&v->counter, &c, c + a)))
114 break;
115 }
116 return (c != u);
117 }
118
119 static inline int
atomic_fetch_add_unless(atomic_t * v,int a,int u)120 atomic_fetch_add_unless(atomic_t *v, int a, int u)
121 {
122 int c = atomic_read(v);
123
124 for (;;) {
125 if (unlikely(c == u))
126 break;
127 if (likely(atomic_fcmpset_int(&v->counter, &c, c + a)))
128 break;
129 }
130 return (c);
131 }
132
133 static inline void
atomic_clear_mask(unsigned int mask,atomic_t * v)134 atomic_clear_mask(unsigned int mask, atomic_t *v)
135 {
136 atomic_clear_int(&v->counter, mask);
137 }
138
139 static inline int
atomic_xchg(atomic_t * v,int i)140 atomic_xchg(atomic_t *v, int i)
141 {
142 return (atomic_swap_int(&v->counter, i));
143 }
144
145 static inline int
atomic_cmpxchg(atomic_t * v,int old,int new)146 atomic_cmpxchg(atomic_t *v, int old, int new)
147 {
148 int ret = old;
149
150 for (;;) {
151 if (atomic_fcmpset_int(&v->counter, &ret, new))
152 break;
153 if (ret != old)
154 break;
155 }
156 return (ret);
157 }
158
159 #if defined(__amd64__) || defined(__arm64__) || defined(__i386__)
160 #define LINUXKPI_ATOMIC_8(...) __VA_ARGS__
161 #define LINUXKPI_ATOMIC_16(...) __VA_ARGS__
162 #else
163 #define LINUXKPI_ATOMIC_8(...)
164 #define LINUXKPI_ATOMIC_16(...)
165 #endif
166
167 #if !(defined(i386) || (defined(__powerpc__) && !defined(__powerpc64__)))
168 #define LINUXKPI_ATOMIC_64(...) __VA_ARGS__
169 #else
170 #define LINUXKPI_ATOMIC_64(...)
171 #endif
172
173 #define cmpxchg(ptr, old, new) ({ \
174 union { \
175 __typeof(*(ptr)) val; \
176 u8 u8[0]; \
177 u16 u16[0]; \
178 u32 u32[0]; \
179 u64 u64[0]; \
180 } __ret = { .val = (old) }, __new = { .val = (new) }; \
181 \
182 CTASSERT( \
183 LINUXKPI_ATOMIC_8(sizeof(__ret.val) == 1 ||) \
184 LINUXKPI_ATOMIC_16(sizeof(__ret.val) == 2 ||) \
185 LINUXKPI_ATOMIC_64(sizeof(__ret.val) == 8 ||) \
186 sizeof(__ret.val) == 4); \
187 \
188 switch (sizeof(__ret.val)) { \
189 LINUXKPI_ATOMIC_8( \
190 case 1: \
191 while (!atomic_fcmpset_8((volatile u8 *)(ptr), \
192 __ret.u8, __new.u8[0]) && __ret.val == (old)) \
193 ; \
194 break; \
195 ) \
196 LINUXKPI_ATOMIC_16( \
197 case 2: \
198 while (!atomic_fcmpset_16((volatile u16 *)(ptr), \
199 __ret.u16, __new.u16[0]) && __ret.val == (old)) \
200 ; \
201 break; \
202 ) \
203 case 4: \
204 while (!atomic_fcmpset_32((volatile u32 *)(ptr), \
205 __ret.u32, __new.u32[0]) && __ret.val == (old)) \
206 ; \
207 break; \
208 LINUXKPI_ATOMIC_64( \
209 case 8: \
210 while (!atomic_fcmpset_64((volatile u64 *)(ptr), \
211 __ret.u64, __new.u64[0]) && __ret.val == (old)) \
212 ; \
213 break; \
214 ) \
215 } \
216 __ret.val; \
217 })
218
219 #define cmpxchg64(...) cmpxchg(__VA_ARGS__)
220 #define cmpxchg_relaxed(...) cmpxchg(__VA_ARGS__)
221
222 #define xchg(ptr, new) ({ \
223 union { \
224 __typeof(*(ptr)) val; \
225 u8 u8[0]; \
226 u16 u16[0]; \
227 u32 u32[0]; \
228 u64 u64[0]; \
229 } __ret, __new = { .val = (new) }; \
230 \
231 CTASSERT( \
232 LINUXKPI_ATOMIC_8(sizeof(__ret.val) == 1 ||) \
233 LINUXKPI_ATOMIC_16(sizeof(__ret.val) == 2 ||) \
234 LINUXKPI_ATOMIC_64(sizeof(__ret.val) == 8 ||) \
235 sizeof(__ret.val) == 4); \
236 \
237 switch (sizeof(__ret.val)) { \
238 LINUXKPI_ATOMIC_8( \
239 case 1: \
240 __ret.val = READ_ONCE(*ptr); \
241 while (!atomic_fcmpset_8((volatile u8 *)(ptr), \
242 __ret.u8, __new.u8[0])) \
243 ; \
244 break; \
245 ) \
246 LINUXKPI_ATOMIC_16( \
247 case 2: \
248 __ret.val = READ_ONCE(*ptr); \
249 while (!atomic_fcmpset_16((volatile u16 *)(ptr), \
250 __ret.u16, __new.u16[0])) \
251 ; \
252 break; \
253 ) \
254 case 4: \
255 __ret.u32[0] = atomic_swap_32((volatile u32 *)(ptr), \
256 __new.u32[0]); \
257 break; \
258 LINUXKPI_ATOMIC_64( \
259 case 8: \
260 __ret.u64[0] = atomic_swap_64((volatile u64 *)(ptr), \
261 __new.u64[0]); \
262 break; \
263 ) \
264 } \
265 __ret.val; \
266 })
267
268 #define try_cmpxchg(p, op, n) \
269 ({ \
270 __typeof(p) __op = (__typeof((p)))(op); \
271 __typeof(*(p)) __o = *__op; \
272 __typeof(*(p)) __p = __sync_val_compare_and_swap((p), (__o), (n)); \
273 if (__p != __o) \
274 *__op = __p; \
275 (__p == __o); \
276 })
277
278 #define __atomic_try_cmpxchg(type, _p, _po, _n) \
279 ({ \
280 __typeof(_po) __po = (_po); \
281 __typeof(*(_po)) __r, __o = *__po; \
282 __r = atomic_cmpxchg##type((_p), __o, (_n)); \
283 if (unlikely(__r != __o)) \
284 *__po = __r; \
285 likely(__r == __o); \
286 })
287
288 #define atomic_try_cmpxchg(_p, _po, _n) __atomic_try_cmpxchg(, _p, _po, _n)
289
290 static inline int
atomic_dec_if_positive(atomic_t * v)291 atomic_dec_if_positive(atomic_t *v)
292 {
293 int retval;
294 int old;
295
296 old = atomic_read(v);
297 for (;;) {
298 retval = old - 1;
299 if (unlikely(retval < 0))
300 break;
301 if (likely(atomic_fcmpset_int(&v->counter, &old, retval)))
302 break;
303 }
304 return (retval);
305 }
306
307 #define LINUX_ATOMIC_OP(op, c_op) \
308 static inline void atomic_##op(int i, atomic_t *v) \
309 { \
310 int c, old; \
311 \
312 c = v->counter; \
313 while ((old = atomic_cmpxchg(v, c, c c_op i)) != c) \
314 c = old; \
315 }
316
317 #define LINUX_ATOMIC_FETCH_OP(op, c_op) \
318 static inline int atomic_fetch_##op(int i, atomic_t *v) \
319 { \
320 int c, old; \
321 \
322 c = v->counter; \
323 while ((old = atomic_cmpxchg(v, c, c c_op i)) != c) \
324 c = old; \
325 \
326 return (c); \
327 }
328
329 static inline int
atomic_fetch_inc(atomic_t * v)330 atomic_fetch_inc(atomic_t *v)
331 {
332
333 return ((atomic_inc_return(v) - 1));
334 }
335
336 LINUX_ATOMIC_OP(or, |)
337 LINUX_ATOMIC_OP(and, &)
338 LINUX_ATOMIC_OP(andnot, &~)
339 LINUX_ATOMIC_OP(xor, ^)
340
341 LINUX_ATOMIC_FETCH_OP(or, |)
342 LINUX_ATOMIC_FETCH_OP(and, &)
343 LINUX_ATOMIC_FETCH_OP(andnot, &~)
344 LINUX_ATOMIC_FETCH_OP(xor, ^)
345
346 #endif /* _LINUXKPI_ASM_ATOMIC_H_ */
347