1 /*
2 * Copyright (c) 2003, 2011, Oracle and/or its affiliates. All rights reserved.
3 * Copyright 2007, 2008, 2011 Red Hat, Inc.
4 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
5 *
6 * This code is free software; you can redistribute it and/or modify it
7 * under the terms of the GNU General Public License version 2 only, as
8 * published by the Free Software Foundation.
9 *
10 * This code is distributed in the hope that it will be useful, but WITHOUT
11 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
12 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
13 * version 2 for more details (a copy is included in the LICENSE file that
14 * accompanied this code).
15 *
16 * You should have received a copy of the GNU General Public License version
17 * 2 along with this work; if not, write to the Free Software Foundation,
18 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
19 *
20 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
21 * or visit www.oracle.com if you need additional information or have any
22 * questions.
23 *
24 */
25
26 #ifndef OS_CPU_BSD_ZERO_VM_ATOMIC_BSD_ZERO_INLINE_HPP
27 #define OS_CPU_BSD_ZERO_VM_ATOMIC_BSD_ZERO_INLINE_HPP
28
29 #include "orderAccess_bsd_zero.inline.hpp"
30 #include "runtime/atomic.hpp"
31 #include "runtime/os.hpp"
32 #include "vm_version_zero.hpp"
33
34 // Implementation of class atomic
35
36 #ifdef M68K
37
38 /*
39 * __m68k_cmpxchg
40 *
41 * Atomically store newval in *ptr if *ptr is equal to oldval for user space.
42 * Returns newval on success and oldval if no exchange happened.
43 * This implementation is processor specific and works on
44 * 68020 68030 68040 and 68060.
45 *
46 * It will not work on ColdFire, 68000 and 68010 since they lack the CAS
47 * instruction.
48 * Using a kernelhelper would be better for arch complete implementation.
49 *
50 */
51
52 static inline int __m68k_cmpxchg(int oldval, int newval, volatile int *ptr) {
53 int ret;
54 __asm __volatile ("cas%.l %0,%2,%1"
55 : "=d" (ret), "+m" (*(ptr))
56 : "d" (newval), "0" (oldval));
57 return ret;
58 }
59
60 /* Perform an atomic compare and swap: if the current value of `*PTR'
61 is OLDVAL, then write NEWVAL into `*PTR'. Return the contents of
62 `*PTR' before the operation.*/
63 static inline int m68k_compare_and_swap(volatile int *ptr,
64 int oldval,
65 int newval) {
66 for (;;) {
67 int prev = *ptr;
68 if (prev != oldval)
69 return prev;
70
71 if (__m68k_cmpxchg (prev, newval, ptr) == newval)
72 // Success.
73 return prev;
74
75 // We failed even though prev == oldval. Try again.
76 }
77 }
78
79 /* Atomically add an int to memory. */
80 static inline int m68k_add_and_fetch(volatile int *ptr, int add_value) {
81 for (;;) {
82 // Loop until success.
83
84 int prev = *ptr;
85
86 if (__m68k_cmpxchg (prev, prev + add_value, ptr) == prev + add_value)
87 return prev + add_value;
88 }
89 }
90
91 /* Atomically write VALUE into `*PTR' and returns the previous
92 contents of `*PTR'. */
93 static inline int m68k_lock_test_and_set(volatile int *ptr, int newval) {
94 for (;;) {
95 // Loop until success.
96 int prev = *ptr;
97
98 if (__m68k_cmpxchg (prev, newval, ptr) == prev)
99 return prev;
100 }
101 }
102 #endif // M68K
103
104 #ifdef ARM
105
106 /*
107 * __kernel_cmpxchg
108 *
109 * Atomically store newval in *ptr if *ptr is equal to oldval for user space.
110 * Return zero if *ptr was changed or non-zero if no exchange happened.
111 * The C flag is also set if *ptr was changed to allow for assembly
112 * optimization in the calling code.
113 *
114 */
115
116 typedef int (__kernel_cmpxchg_t)(int oldval, int newval, volatile int *ptr);
117 #define __kernel_cmpxchg (*(__kernel_cmpxchg_t *) 0xffff0fc0)
118
119
120
121 /* Perform an atomic compare and swap: if the current value of `*PTR'
122 is OLDVAL, then write NEWVAL into `*PTR'. Return the contents of
123 `*PTR' before the operation.*/
124 static inline int arm_compare_and_swap(volatile int *ptr,
125 int oldval,
126 int newval) {
127 for (;;) {
128 int prev = *ptr;
129 if (prev != oldval)
130 return prev;
131
132 if (__kernel_cmpxchg (prev, newval, ptr) == 0)
133 // Success.
134 return prev;
135
136 // We failed even though prev == oldval. Try again.
137 }
138 }
139
140 /* Atomically add an int to memory. */
141 static inline int arm_add_and_fetch(volatile int *ptr, int add_value) {
142 for (;;) {
143 // Loop until a __kernel_cmpxchg succeeds.
144
145 int prev = *ptr;
146
147 if (__kernel_cmpxchg (prev, prev + add_value, ptr) == 0)
148 return prev + add_value;
149 }
150 }
151
152 /* Atomically write VALUE into `*PTR' and returns the previous
153 contents of `*PTR'. */
154 static inline int arm_lock_test_and_set(volatile int *ptr, int newval) {
155 for (;;) {
156 // Loop until a __kernel_cmpxchg succeeds.
157 int prev = *ptr;
158
159 if (__kernel_cmpxchg (prev, newval, ptr) == 0)
160 return prev;
161 }
162 }
163 #endif // ARM
164
165 inline void Atomic::store(jint store_value, volatile jint* dest) {
166 #if !defined(ARM) && !defined(M68K)
167 __sync_synchronize();
168 #endif
169 *dest = store_value;
170 }
171
172 inline void Atomic::store_ptr(intptr_t store_value, intptr_t* dest) {
173 #if !defined(ARM) && !defined(M68K)
174 __sync_synchronize();
175 #endif
176 *dest = store_value;
177 }
178
179 inline jint Atomic::add(jint add_value, volatile jint* dest) {
180 #ifdef ARM
181 return arm_add_and_fetch(dest, add_value);
182 #else
183 #ifdef M68K
184 return m68k_add_and_fetch(dest, add_value);
185 #else
186 return __sync_add_and_fetch(dest, add_value);
187 #endif // M68K
188 #endif // ARM
189 }
190
191 inline intptr_t Atomic::add_ptr(intptr_t add_value, volatile intptr_t* dest) {
192 #ifdef ARM
193 return arm_add_and_fetch(dest, add_value);
194 #else
195 #ifdef M68K
196 return m68k_add_and_fetch(dest, add_value);
197 #else
198 return __sync_add_and_fetch(dest, add_value);
199 #endif // M68K
200 #endif // ARM
201 }
202
203 inline void* Atomic::add_ptr(intptr_t add_value, volatile void* dest) {
204 return (void *) add_ptr(add_value, (volatile intptr_t *) dest);
205 }
206
207 inline void Atomic::inc(volatile jint* dest) {
208 add(1, dest);
209 }
210
211 inline void Atomic::inc_ptr(volatile intptr_t* dest) {
212 add_ptr(1, dest);
213 }
214
215 inline void Atomic::inc_ptr(volatile void* dest) {
216 add_ptr(1, dest);
217 }
218
219 inline void Atomic::dec(volatile jint* dest) {
220 add(-1, dest);
221 }
222
223 inline void Atomic::dec_ptr(volatile intptr_t* dest) {
224 add_ptr(-1, dest);
225 }
226
227 inline void Atomic::dec_ptr(volatile void* dest) {
228 add_ptr(-1, dest);
229 }
230
231 inline jint Atomic::xchg(jint exchange_value, volatile jint* dest) {
232 #ifdef ARM
233 return arm_lock_test_and_set(dest, exchange_value);
234 #else
235 #ifdef M68K
236 return m68k_lock_test_and_set(dest, exchange_value);
237 #else
238 // __sync_lock_test_and_set is a bizarrely named atomic exchange
239 // operation. Note that some platforms only support this with the
240 // limitation that the only valid value to store is the immediate
241 // constant 1. There is a test for this in JNI_CreateJavaVM().
242 return __sync_lock_test_and_set (dest, exchange_value);
243 #endif // M68K
244 #endif // ARM
245 }
246
247 inline intptr_t Atomic::xchg_ptr(intptr_t exchange_value,
248 volatile intptr_t* dest) {
249 #ifdef ARM
250 return arm_lock_test_and_set(dest, exchange_value);
251 #else
252 #ifdef M68K
253 return m68k_lock_test_and_set(dest, exchange_value);
254 #else
255 return __sync_lock_test_and_set (dest, exchange_value);
256 #endif // M68K
257 #endif // ARM
258 }
259
260 inline void* Atomic::xchg_ptr(void* exchange_value, volatile void* dest) {
261 return (void *) xchg_ptr((intptr_t) exchange_value,
262 (volatile intptr_t*) dest);
263 }
264
265 inline jint Atomic::cmpxchg(jint exchange_value,
266 volatile jint* dest,
267 jint compare_value) {
268 #ifdef ARM
269 return arm_compare_and_swap(dest, compare_value, exchange_value);
270 #else
271 #ifdef M68K
272 return m68k_compare_and_swap(dest, compare_value, exchange_value);
273 #else
274 return __sync_val_compare_and_swap(dest, compare_value, exchange_value);
275 #endif // M68K
276 #endif // ARM
277 }
278
279 inline jlong Atomic::cmpxchg(jlong exchange_value,
280 volatile jlong* dest,
281 jlong compare_value) {
282
283 return __sync_val_compare_and_swap(dest, compare_value, exchange_value);
284 }
285
286 inline intptr_t Atomic::cmpxchg_ptr(intptr_t exchange_value,
287 volatile intptr_t* dest,
288 intptr_t compare_value) {
289 #ifdef ARM
290 return arm_compare_and_swap(dest, compare_value, exchange_value);
291 #else
292 #ifdef M68K
293 return m68k_compare_and_swap(dest, compare_value, exchange_value);
294 #else
295 return __sync_val_compare_and_swap(dest, compare_value, exchange_value);
296 #endif // M68K
297 #endif // ARM
298 }
299
300 inline void* Atomic::cmpxchg_ptr(void* exchange_value,
301 volatile void* dest,
302 void* compare_value) {
303
304 return (void *) cmpxchg_ptr((intptr_t) exchange_value,
305 (volatile intptr_t*) dest,
306 (intptr_t) compare_value);
307 }
308
309 inline jlong Atomic::load(volatile jlong* src) {
310 volatile jlong dest;
311 os::atomic_copy64(src, &dest);
312 return dest;
313 }
314
315 inline void Atomic::store(jlong store_value, jlong* dest) {
316 os::atomic_copy64((volatile jlong*)&store_value, (volatile jlong*)dest);
317 }
318
319 inline void Atomic::store(jlong store_value, volatile jlong* dest) {
320 os::atomic_copy64((volatile jlong*)&store_value, dest);
321 }
322
323 #endif // OS_CPU_BSD_ZERO_VM_ATOMIC_BSD_ZERO_INLINE_HPP