Add extern "C" to support linking userspace RCU library with C++ applications
[urcu.git] / urcu / uatomic_arch_s390.h
1 #ifndef _URCU_UATOMIC_ARCH_S390_H
2 #define _URCU_UATOMIC_ARCH_S390_H
3
4 /*
5 * Atomic exchange operations for the S390 architecture. Based on information
6 * taken from the Principles of Operation Appendix A "Conditional Swapping
7 * Instructions (CS, CDS)".
8 *
9 * Copyright (c) 2009 Novell, Inc.
10 * Author: Jan Blunck <jblunck@suse.de>
11 * Copyright (c) 2009 Mathieu Desnoyers <mathieu.desnoyers@polymtl.ca>
12 *
13 * Permission is hereby granted, free of charge, to any person obtaining a copy
14 * of this software and associated documentation files (the "Software"), to
15 * deal in the Software without restriction, including without limitation the
16 * rights to use, copy, modify, merge, publish, distribute, sublicense, and/or
17 * sell copies of the Software, and to permit persons to whom the Software is
18 * furnished to do so, subject to the following conditions:
19 *
20 * The above copyright notice and this permission notice shall be included in
21 * all copies or substantial portions of the Software.
22 *
23 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
24 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
25 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
26 * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
27 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
28 * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS
29 * IN THE SOFTWARE.
30 */
31
32 #include <urcu/compiler.h>
33 #include <urcu/system.h>
34
35 #ifdef __cplusplus
36 extern "C" {
37 #endif
38
39 #ifndef __SIZEOF_LONG__
40 #ifdef __s390x__
41 #define __SIZEOF_LONG__ 8
42 #else
43 #define __SIZEOF_LONG__ 4
44 #endif
45 #endif
46
47 #ifndef BITS_PER_LONG
48 #define BITS_PER_LONG (__SIZEOF_LONG__ * 8)
49 #endif
50
51 #if __GNUC__ > 3 || (__GNUC__ == 3 && __GNUC_MINOR__ > 2)
52 #define COMPILER_HAVE_SHORT_MEM_OPERAND
53 #endif
54
55 /*
56 * MEMOP assembler operand rules:
57 * - op refer to MEMOP_IN operand
58 * - MEMOP_IN can expand to more than a single operand. Use it at the end of
59 * operand list only.
60 */
61
62 #ifdef COMPILER_HAVE_SHORT_MEM_OPERAND
63
64 #define MEMOP_OUT(addr) "=Q" (*(addr))
65 #define MEMOP_IN "Q" (*(addr))
66 #define MEMOP_REF(op) #op /* op refer to MEMOP_IN operand */
67
68 #else /* !COMPILER_HAVE_SHORT_MEM_OPERAND */
69
70 #define MEMOP_OUT(addr) "=m" (*(addr))
71 #define MEMOP_IN "a" (addr), "m" (*(addr))
72 #define MEMOP_REF(op) "0(" #op ")" /* op refer to MEMOP_IN operand */
73
74 #endif /* !COMPILER_HAVE_SHORT_MEM_OPERAND */
75
76 struct __uatomic_dummy {
77 unsigned long v[10];
78 };
79 #define __hp(x) ((struct __uatomic_dummy *)(x))
80
81 #define uatomic_set(addr, v) STORE_SHARED(*(addr), (v))
82 #define uatomic_read(addr) LOAD_SHARED(*(addr))
83
84 /* xchg */
85
86 static inline __attribute__((always_inline))
87 unsigned long _uatomic_exchange(volatile void *addr, unsigned long val, int len)
88 {
89 switch (len) {
90 case 4:
91 {
92 unsigned int old_val;
93
94 __asm__ __volatile__(
95 "0: cs %0,%2," MEMOP_REF(%3) "\n"
96 " brc 4,0b\n"
97 : "=&r" (old_val), MEMOP_OUT (__hp(addr))
98 : "r" (val), MEMOP_IN (__hp(addr))
99 : "memory", "cc");
100 return old_val;
101 }
102 #if (BITS_PER_LONG == 64)
103 case 8:
104 {
105 unsigned long old_val;
106
107 __asm__ __volatile__(
108 "0: csg %0,%2," MEMOP_REF(%3) "\n"
109 " brc 4,0b\n"
110 : "=&r" (old_val), MEMOP_OUT (__hp(addr))
111 : "r" (val), MEMOP_IN (__hp(addr))
112 : "memory", "cc");
113 return old_val;
114 }
115 #endif
116 default:
117 __asm__ __volatile__(".long 0xd00d00");
118 }
119
120 return 0;
121 }
122
123 #define uatomic_xchg(addr, v) \
124 (__typeof__(*(addr))) _uatomic_exchange((addr), (unsigned long)(v), \
125 sizeof(*(addr)))
126
127 /* cmpxchg */
128
129 static inline __attribute__((always_inline))
130 unsigned long _uatomic_cmpxchg(void *addr, unsigned long old,
131 unsigned long _new, int len)
132 {
133 switch (len) {
134 case 4:
135 {
136 unsigned int old_val = (unsigned int)old;
137
138 __asm__ __volatile__(
139 " cs %0,%2," MEMOP_REF(%3) "\n"
140 : "+r" (old_val), MEMOP_OUT (__hp(addr))
141 : "r" (_new), MEMOP_IN (__hp(addr))
142 : "memory", "cc");
143 return old_val;
144 }
145 #if (BITS_PER_LONG == 64)
146 case 8:
147 {
148 __asm__ __volatile__(
149 " csg %0,%2," MEMOP_REF(%3) "\n"
150 : "+r" (old), MEMOP_OUT (__hp(addr))
151 : "r" (_new), MEMOP_IN (__hp(addr))
152 : "memory", "cc");
153 return old;
154 }
155 #endif
156 default:
157 __asm__ __volatile__(".long 0xd00d00");
158 }
159
160 return 0;
161 }
162
163 #define uatomic_cmpxchg(addr, old, _new) \
164 (__typeof__(*(addr))) _uatomic_cmpxchg((addr), \
165 (unsigned long)(old), \
166 (unsigned long)(_new), \
167 sizeof(*(addr)))
168
169 /* uatomic_add_return */
170
171 static inline __attribute__((always_inline))
172 unsigned long _uatomic_add_return(void *addr, unsigned long val, int len)
173 {
174 switch (len) {
175 case 4:
176 {
177 unsigned int old, oldt;
178
179 oldt = uatomic_read((unsigned int *)addr);
180 do {
181 old = oldt;
182 oldt = _uatomic_cmpxchg(addr, old, old + val, 4);
183 } while (oldt != old);
184
185 return old + val;
186 }
187 #if (BITS_PER_LONG == 64)
188 case 8:
189 {
190 unsigned long old, oldt;
191
192 oldt = uatomic_read((unsigned long *)addr);
193 do {
194 old = oldt;
195 oldt = _uatomic_cmpxchg(addr, old, old + val, 8);
196 } while (oldt != old);
197
198 return old + val;
199 }
200 #endif
201 }
202 __builtin_trap();
203 return 0;
204 }
205
206 #define uatomic_add_return(addr, v) \
207 ((__typeof__(*(addr))) _uatomic_add_return((addr), \
208 (unsigned long)(v), \
209 sizeof(*(addr))))
210
211 /* uatomic_sub_return, uatomic_add, uatomic_sub, uatomic_inc, uatomic_dec */
212
213 #define uatomic_sub_return(addr, v) uatomic_add_return((addr), -(v))
214
215 #define uatomic_add(addr, v) (void)uatomic_add_return((addr), (v))
216 #define uatomic_sub(addr, v) (void)uatomic_sub_return((addr), (v))
217
218 #define uatomic_inc(addr) uatomic_add((addr), 1)
219 #define uatomic_dec(addr) uatomic_add((addr), -1)
220
221 #define compat_uatomic_cmpxchg(ptr, old, _new) uatomic_cmpxchg(ptr, old, _new)
222
223 #ifdef __cplusplus
224 }
225 #endif
226
227 #endif /* _URCU_UATOMIC_ARCH_S390_H */
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