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-rw-r--r--arch/s390/include/asm/cmpxchg.h205
1 files changed, 205 insertions, 0 deletions
diff --git a/arch/s390/include/asm/cmpxchg.h b/arch/s390/include/asm/cmpxchg.h
new file mode 100644
index 000000000000..4052df9030cb
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+++ b/arch/s390/include/asm/cmpxchg.h
@@ -0,0 +1,205 @@
1/*
2 * Copyright IBM Corp. 1999, 2011
3 *
4 * Author(s): Martin Schwidefsky <schwidefsky@de.ibm.com>,
5 */
6
7#ifndef __ASM_CMPXCHG_H
8#define __ASM_CMPXCHG_H
9
10#include <linux/types.h>
11
12extern void __xchg_called_with_bad_pointer(void);
13
14static inline unsigned long __xchg(unsigned long x, void *ptr, int size)
15{
16 unsigned long addr, old;
17 int shift;
18
19 switch (size) {
20 case 1:
21 addr = (unsigned long) ptr;
22 shift = (3 ^ (addr & 3)) << 3;
23 addr ^= addr & 3;
24 asm volatile(
25 " l %0,%4\n"
26 "0: lr 0,%0\n"
27 " nr 0,%3\n"
28 " or 0,%2\n"
29 " cs %0,0,%4\n"
30 " jl 0b\n"
31 : "=&d" (old), "=Q" (*(int *) addr)
32 : "d" (x << shift), "d" (~(255 << shift)),
33 "Q" (*(int *) addr) : "memory", "cc", "0");
34 return old >> shift;
35 case 2:
36 addr = (unsigned long) ptr;
37 shift = (2 ^ (addr & 2)) << 3;
38 addr ^= addr & 2;
39 asm volatile(
40 " l %0,%4\n"
41 "0: lr 0,%0\n"
42 " nr 0,%3\n"
43 " or 0,%2\n"
44 " cs %0,0,%4\n"
45 " jl 0b\n"
46 : "=&d" (old), "=Q" (*(int *) addr)
47 : "d" (x << shift), "d" (~(65535 << shift)),
48 "Q" (*(int *) addr) : "memory", "cc", "0");
49 return old >> shift;
50 case 4:
51 asm volatile(
52 " l %0,%3\n"
53 "0: cs %0,%2,%3\n"
54 " jl 0b\n"
55 : "=&d" (old), "=Q" (*(int *) ptr)
56 : "d" (x), "Q" (*(int *) ptr)
57 : "memory", "cc");
58 return old;
59#ifdef CONFIG_64BIT
60 case 8:
61 asm volatile(
62 " lg %0,%3\n"
63 "0: csg %0,%2,%3\n"
64 " jl 0b\n"
65 : "=&d" (old), "=m" (*(long *) ptr)
66 : "d" (x), "Q" (*(long *) ptr)
67 : "memory", "cc");
68 return old;
69#endif /* CONFIG_64BIT */
70 }
71 __xchg_called_with_bad_pointer();
72 return x;
73}
74
75#define xchg(ptr, x) \
76({ \
77 __typeof__(*(ptr)) __ret; \
78 __ret = (__typeof__(*(ptr))) \
79 __xchg((unsigned long)(x), (void *)(ptr), sizeof(*(ptr)));\
80 __ret; \
81})
82
83/*
84 * Atomic compare and exchange. Compare OLD with MEM, if identical,
85 * store NEW in MEM. Return the initial value in MEM. Success is
86 * indicated by comparing RETURN with OLD.
87 */
88
89#define __HAVE_ARCH_CMPXCHG
90
91extern void __cmpxchg_called_with_bad_pointer(void);
92
93static inline unsigned long __cmpxchg(void *ptr, unsigned long old,
94 unsigned long new, int size)
95{
96 unsigned long addr, prev, tmp;
97 int shift;
98
99 switch (size) {
100 case 1:
101 addr = (unsigned long) ptr;
102 shift = (3 ^ (addr & 3)) << 3;
103 addr ^= addr & 3;
104 asm volatile(
105 " l %0,%2\n"
106 "0: nr %0,%5\n"
107 " lr %1,%0\n"
108 " or %0,%3\n"
109 " or %1,%4\n"
110 " cs %0,%1,%2\n"
111 " jnl 1f\n"
112 " xr %1,%0\n"
113 " nr %1,%5\n"
114 " jnz 0b\n"
115 "1:"
116 : "=&d" (prev), "=&d" (tmp), "=Q" (*(int *) ptr)
117 : "d" (old << shift), "d" (new << shift),
118 "d" (~(255 << shift)), "Q" (*(int *) ptr)
119 : "memory", "cc");
120 return prev >> shift;
121 case 2:
122 addr = (unsigned long) ptr;
123 shift = (2 ^ (addr & 2)) << 3;
124 addr ^= addr & 2;
125 asm volatile(
126 " l %0,%2\n"
127 "0: nr %0,%5\n"
128 " lr %1,%0\n"
129 " or %0,%3\n"
130 " or %1,%4\n"
131 " cs %0,%1,%2\n"
132 " jnl 1f\n"
133 " xr %1,%0\n"
134 " nr %1,%5\n"
135 " jnz 0b\n"
136 "1:"
137 : "=&d" (prev), "=&d" (tmp), "=Q" (*(int *) ptr)
138 : "d" (old << shift), "d" (new << shift),
139 "d" (~(65535 << shift)), "Q" (*(int *) ptr)
140 : "memory", "cc");
141 return prev >> shift;
142 case 4:
143 asm volatile(
144 " cs %0,%3,%1\n"
145 : "=&d" (prev), "=Q" (*(int *) ptr)
146 : "0" (old), "d" (new), "Q" (*(int *) ptr)
147 : "memory", "cc");
148 return prev;
149#ifdef CONFIG_64BIT
150 case 8:
151 asm volatile(
152 " csg %0,%3,%1\n"
153 : "=&d" (prev), "=Q" (*(long *) ptr)
154 : "0" (old), "d" (new), "Q" (*(long *) ptr)
155 : "memory", "cc");
156 return prev;
157#endif /* CONFIG_64BIT */
158 }
159 __cmpxchg_called_with_bad_pointer();
160 return old;
161}
162
163#define cmpxchg(ptr, o, n) \
164 ((__typeof__(*(ptr)))__cmpxchg((ptr), (unsigned long)(o), \
165 (unsigned long)(n), sizeof(*(ptr))))
166
167#include <asm-generic/cmpxchg-local.h>
168
169static inline unsigned long __cmpxchg_local(void *ptr,
170 unsigned long old,
171 unsigned long new, int size)
172{
173 switch (size) {
174 case 1:
175 case 2:
176 case 4:
177#ifdef CONFIG_64BIT
178 case 8:
179#endif
180 return __cmpxchg(ptr, old, new, size);
181 default:
182 return __cmpxchg_local_generic(ptr, old, new, size);
183 }
184
185 return old;
186}
187
188/*
189 * cmpxchg_local and cmpxchg64_local are atomic wrt current CPU. Always make
190 * them available.
191 */
192#define cmpxchg_local(ptr, o, n) \
193 ((__typeof__(*(ptr)))__cmpxchg_local((ptr), (unsigned long)(o), \
194 (unsigned long)(n), sizeof(*(ptr))))
195#ifdef CONFIG_64BIT
196#define cmpxchg64_local(ptr, o, n) \
197({ \
198 BUILD_BUG_ON(sizeof(*(ptr)) != 8); \
199 cmpxchg_local((ptr), (o), (n)); \
200})
201#else
202#define cmpxchg64_local(ptr, o, n) __cmpxchg64_local_generic((ptr), (o), (n))
203#endif
204
205#endif /* __ASM_CMPXCHG_H */
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