1 /*
2 * Copyright (c) 2003, 2014, 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 "runtime/atomic.hpp"
30 #include "runtime/os.hpp"
31
32 // Implementation of class atomic
33
34 #ifdef M68K
35
36 /*
37 * __m68k_cmpxchg
38 *
39 * Atomically store newval in *ptr if *ptr is equal to oldval for user space.
40 * Returns newval on success and oldval if no exchange happened.
41 * This implementation is processor specific and works on
42 * 68020 68030 68040 and 68060.
43 *
44 * It will not work on ColdFire, 68000 and 68010 since they lack the CAS
45 * instruction.
46 * Using a kernelhelper would be better for arch complete implementation.
47 *
48 */
49
50 static inline int __m68k_cmpxchg(int oldval, int newval, volatile int *ptr) {
51 int ret;
52 __asm __volatile ("cas%.l %0,%2,%1"
53 : "=d" (ret), "+m" (*(ptr))
54 : "d" (newval), "0" (oldval));
55 return ret;
56 }
57
58 /* Perform an atomic compare and swap: if the current value of `*PTR'
59 is OLDVAL, then write NEWVAL into `*PTR'. Return the contents of
60 `*PTR' before the operation.*/
61 static inline int m68k_compare_and_swap(volatile int *ptr,
62 int oldval,
63 int newval) {
64 for (;;) {
65 int prev = *ptr;
66 if (prev != oldval)
67 return prev;
68
69 if (__m68k_cmpxchg (prev, newval, ptr) == newval)
70 // Success.
71 return prev;
72
73 // We failed even though prev == oldval. Try again.
74 }
75 }
76
77 /* Atomically add an int to memory. */
78 static inline int m68k_add_and_fetch(volatile int *ptr, int add_value) {
79 for (;;) {
80 // Loop until success.
81
82 int prev = *ptr;
83
84 if (__m68k_cmpxchg (prev, prev + add_value, ptr) == prev + add_value)
85 return prev + add_value;
86 }
87 }
88
89 /* Atomically write VALUE into `*PTR' and returns the previous
90 contents of `*PTR'. */
91 static inline int m68k_lock_test_and_set(volatile int *ptr, int newval) {
92 for (;;) {
93 // Loop until success.
94 int prev = *ptr;
95
96 if (__m68k_cmpxchg (prev, newval, ptr) == prev)
97 return prev;
98 }
99 }
100 #endif // M68K
101
102 #ifdef ARM
103
104 /*
105 * __kernel_cmpxchg
106 *
107 * Atomically store newval in *ptr if *ptr is equal to oldval for user space.
108 * Return zero if *ptr was changed or non-zero if no exchange happened.
109 * The C flag is also set if *ptr was changed to allow for assembly
110 * optimization in the calling code.
111 *
112 */
113
114 typedef int (__kernel_cmpxchg_t)(int oldval, int newval, volatile int *ptr);
115 #define __kernel_cmpxchg (*(__kernel_cmpxchg_t *) 0xffff0fc0)
116
117
118
119 /* Perform an atomic compare and swap: if the current value of `*PTR'
120 is OLDVAL, then write NEWVAL into `*PTR'. Return the contents of
121 `*PTR' before the operation.*/
122 static inline int arm_compare_and_swap(volatile int *ptr,
123 int oldval,
124 int newval) {
125 for (;;) {
126 int prev = *ptr;
127 if (prev != oldval)
128 return prev;
129
130 if (__kernel_cmpxchg (prev, newval, ptr) == 0)
131 // Success.
132 return prev;
133
134 // We failed even though prev == oldval. Try again.
135 }
136 }
137
138 /* Atomically add an int to memory. */
139 static inline int arm_add_and_fetch(volatile int *ptr, int add_value) {
140 for (;;) {
141 // Loop until a __kernel_cmpxchg succeeds.
142
143 int prev = *ptr;
144
145 if (__kernel_cmpxchg (prev, prev + add_value, ptr) == 0)
146 return prev + add_value;
147 }
148 }
149
150 /* Atomically write VALUE into `*PTR' and returns the previous
151 contents of `*PTR'. */
152 static inline int arm_lock_test_and_set(volatile int *ptr, int newval) {
153 for (;;) {
154 // Loop until a __kernel_cmpxchg succeeds.
155 int prev = *ptr;
156
157 if (__kernel_cmpxchg (prev, newval, ptr) == 0)
158 return prev;
159 }
160 }
161 #endif // ARM
162
163 inline void Atomic::store(jint store_value, volatile jint* dest) {
164 #if !defined(ARM) && !defined(M68K)
165 __sync_synchronize();
166 #endif
167 *dest = store_value;
168 }
169
170 inline void Atomic::store_ptr(intptr_t store_value, intptr_t* dest) {
171 #if !defined(ARM) && !defined(M68K)
172 __sync_synchronize();
173 #endif
174 *dest = store_value;
175 }
176
177 inline jint Atomic::add(jint add_value, volatile jint* dest) {
178 #ifdef ARM
179 return arm_add_and_fetch(dest, add_value);
180 #else
181 #ifdef M68K
182 return m68k_add_and_fetch(dest, add_value);
183 #else
184 return __sync_add_and_fetch(dest, add_value);
185 #endif // M68K
186 #endif // ARM
187 }
188
189 inline intptr_t Atomic::add_ptr(intptr_t add_value, volatile intptr_t* dest) {
190 #ifdef ARM
191 return arm_add_and_fetch(dest, add_value);
192 #else
193 #ifdef M68K
194 return m68k_add_and_fetch(dest, add_value);
195 #else
196 return __sync_add_and_fetch(dest, add_value);
197 #endif // M68K
198 #endif // ARM
199 }
200
201 inline void* Atomic::add_ptr(intptr_t add_value, volatile void* dest) {
202 return (void *) add_ptr(add_value, (volatile intptr_t *) dest);
203 }
204
205 inline void Atomic::inc(volatile jint* dest) {
206 add(1, dest);
207 }
208
209 inline void Atomic::inc_ptr(volatile intptr_t* dest) {
210 add_ptr(1, dest);
211 }
212
213 inline void Atomic::inc_ptr(volatile void* dest) {
214 add_ptr(1, dest);
215 }
216
217 inline void Atomic::dec(volatile jint* dest) {
218 add(-1, dest);
219 }
220
221 inline void Atomic::dec_ptr(volatile intptr_t* dest) {
222 add_ptr(-1, dest);
223 }
224
225 inline void Atomic::dec_ptr(volatile void* dest) {
226 add_ptr(-1, dest);
227 }
228
229 inline jint Atomic::xchg(jint exchange_value, volatile jint* dest) {
230 #ifdef ARM
231 return arm_lock_test_and_set(dest, exchange_value);
232 #else
233 #ifdef M68K
234 return m68k_lock_test_and_set(dest, exchange_value);
235 #else
236 // __sync_lock_test_and_set is a bizarrely named atomic exchange
237 // operation. Note that some platforms only support this with the
238 // limitation that the only valid value to store is the immediate
239 // constant 1. There is a test for this in JNI_CreateJavaVM().
240 return __sync_lock_test_and_set (dest, exchange_value);
241 #endif // M68K
242 #endif // ARM
243 }
244
245 inline intptr_t Atomic::xchg_ptr(intptr_t exchange_value,
246 volatile intptr_t* dest) {
247 #ifdef ARM
248 return arm_lock_test_and_set(dest, exchange_value);
249 #else
250 #ifdef M68K
251 return m68k_lock_test_and_set(dest, exchange_value);
252 #else
253 return __sync_lock_test_and_set (dest, exchange_value);
254 #endif // M68K
255 #endif // ARM
256 }
257
258 inline void* Atomic::xchg_ptr(void* exchange_value, volatile void* dest) {
259 return (void *) xchg_ptr((intptr_t) exchange_value,
260 (volatile intptr_t*) dest);
261 }
262
263 inline jint Atomic::cmpxchg(jint exchange_value,
264 volatile jint* dest,
265 jint compare_value) {
266 #ifdef ARM
267 return arm_compare_and_swap(dest, compare_value, exchange_value);
268 #else
269 #ifdef M68K
270 return m68k_compare_and_swap(dest, compare_value, exchange_value);
271 #else
272 return __sync_val_compare_and_swap(dest, compare_value, exchange_value);
273 #endif // M68K
274 #endif // ARM
275 }
276
277 inline jlong Atomic::cmpxchg(jlong exchange_value,
278 volatile jlong* dest,
279 jlong compare_value) {
280
281 return __sync_val_compare_and_swap(dest, compare_value, exchange_value);
282 }
283
284 inline intptr_t Atomic::cmpxchg_ptr(intptr_t exchange_value,
285 volatile intptr_t* dest,
286 intptr_t compare_value) {
287 #ifdef ARM
288 return arm_compare_and_swap(dest, compare_value, exchange_value);
289 #else
290 #ifdef M68K
291 return m68k_compare_and_swap(dest, compare_value, exchange_value);
292 #else
293 return __sync_val_compare_and_swap(dest, compare_value, exchange_value);
294 #endif // M68K
295 #endif // ARM
296 }
297
298 inline void* Atomic::cmpxchg_ptr(void* exchange_value,
299 volatile void* dest,
300 void* compare_value) {
301
302 return (void *) cmpxchg_ptr((intptr_t) exchange_value,
303 (volatile intptr_t*) dest,
304 (intptr_t) compare_value);
305 }
306
307 inline jlong Atomic::load(volatile jlong* src) {
308 volatile jlong dest;
309 os::atomic_copy64(src, &dest);
310 return dest;
311 }
312
313 inline void Atomic::store(jlong store_value, jlong* dest) {
314 os::atomic_copy64((volatile jlong*)&store_value, (volatile jlong*)dest);
315 }
316
317 inline void Atomic::store(jlong store_value, volatile jlong* dest) {
318 os::atomic_copy64((volatile jlong*)&store_value, dest);
319 }
320
321 #endif // OS_CPU_BSD_ZERO_VM_ATOMIC_BSD_ZERO_INLINE_HPP