Revert "qsbr urcu: make it safe to call rcu_sychronize from a registered thread."
[urcu.git] / arch_atomic_s390.h
1 #ifndef _ARCH_ATOMIC_S390_H
2 #define _ARCH_ATOMIC_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 *
12 * Permission is hereby granted, free of charge, to any person obtaining a copy
13 * of this software and associated documentation files (the "Software"), to
14 * deal in the Software without restriction, including without limitation the
15 * rights to use, copy, modify, merge, publish, distribute, sublicense, and/or
16 * sell copies of the Software, and to permit persons to whom the Software is
17 * furnished to do so, subject to the following conditions:
18 *
19 * The above copyright notice and this permission notice shall be included in
20 * all copies or substantial portions of the Software.
21 *
22 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
23 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
24 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
25 * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
26 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
27 * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS
28 * IN THE SOFTWARE.
29 */
30
31 #ifndef __SIZEOF_LONG__
32 #ifdef __s390x__
33 #define __SIZEOF_LONG__ 8
34 #else
35 #define __SIZEOF_LONG__ 4
36 #endif
37 #endif
38
39 #ifndef BITS_PER_LONG
40 #define BITS_PER_LONG (__SIZEOF_LONG__ * 8)
41 #endif
42
43 #ifndef _INCLUDE_API_H
44
45 static inline __attribute__((always_inline))
46 unsigned int atomic_exchange_32(volatile unsigned int *addr, unsigned int val)
47 {
48 unsigned int result;
49
50 __asm__ __volatile__(
51 "0: cs %0,%2,%1\n"
52 " brc 4,0b\n"
53 : "=&r"(result), "=m" (*addr)
54 : "r"(val), "m" (*addr)
55 : "memory", "cc");
56
57 return result;
58 }
59
60 #if (BITS_PER_LONG == 64)
61
62 static inline __attribute__((always_inline))
63 unsigned long atomic_exchange_64(volatile unsigned long *addr,
64 unsigned long val)
65 {
66 unsigned long result;
67
68 __asm__ __volatile__(
69 "0: csg %0,%2,%1\n"
70 " brc 4,0b\n"
71 : "=&r"(result), "=m" (*addr)
72 : "r"(val), "m" (*addr)
73 : "memory", "cc");
74
75 return result;
76 }
77
78 #endif
79
80 static inline __attribute__((always_inline))
81 unsigned long _atomic_exchange(volatile void *addr, unsigned long val, int len)
82 {
83 switch (len) {
84 case 4:
85 return atomic_exchange_32(addr, val);
86 #if (BITS_PER_LONG == 64)
87 case 8:
88 return atomic_exchange_64(addr, val);
89 #endif
90 default:
91 __asm__ __volatile__(".long 0xd00d00");
92 }
93
94 return 0;
95 }
96
97 #define xchg(addr, v) \
98 (__typeof__(*(addr))) _atomic_exchange((addr), (unsigned long)(v), \
99 sizeof(*(addr)))
100
101 #endif /* #ifndef _INCLUDE_API_H */
102
103 #endif /* ARCH_ATOMIC_S390_H */
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