summaryrefslogtreecommitdiffstats
path: root/arch/powerpc/include/asm/cmpxchg.h
blob: d1a8d93cccfd483b8181046434ebc3ef55d8704a (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
#ifndef _ASM_POWERPC_CMPXCHG_H_
#define _ASM_POWERPC_CMPXCHG_H_

#ifdef __KERNEL__
#include <linux/compiler.h>
#include <asm/synch.h>
#include <asm/asm-compat.h>

/*
 * Atomic exchange
 *
 * Changes the memory location '*ptr' to be val and returns
 * the previous value stored there.
 */
static __always_inline unsigned long
__xchg_u32(volatile void *p, unsigned long val)
{
	unsigned long prev;

	__asm__ __volatile__(
	PPC_ATOMIC_ENTRY_BARRIER
"1:	lwarx	%0,0,%2 \n"
	PPC405_ERR77(0,%2)
"	stwcx.	%3,0,%2 \n\
	bne-	1b"
	PPC_ATOMIC_EXIT_BARRIER
	: "=&r" (prev), "+m" (*(volatile unsigned int *)p)
	: "r" (p), "r" (val)
	: "cc", "memory");

	return prev;
}

/*
 * Atomic exchange
 *
 * Changes the memory location '*ptr' to be val and returns
 * the previous value stored there.
 */
static __always_inline unsigned long
__xchg_u32_local(volatile void *p, unsigned long val)
{
	unsigned long prev;

	__asm__ __volatile__(
"1:	lwarx	%0,0,%2 \n"
	PPC405_ERR77(0,%2)
"	stwcx.	%3,0,%2 \n\
	bne-	1b"
	: "=&r" (prev), "+m" (*(volatile unsigned int *)p)
	: "r" (p), "r" (val)
	: "cc", "memory");

	return prev;
}

#ifdef CONFIG_PPC64
static __always_inline unsigned long
__xchg_u64(volatile void *p, unsigned long val)
{
	unsigned long prev;

	__asm__ __volatile__(
	PPC_ATOMIC_ENTRY_BARRIER
"1:	ldarx	%0,0,%2 \n"
	PPC405_ERR77(0,%2)
"	stdcx.	%3,0,%2 \n\
	bne-	1b"
	PPC_ATOMIC_EXIT_BARRIER
	: "=&r" (prev), "+m" (*(volatile unsigned long *)p)
	: "r" (p), "r" (val)
	: "cc", "memory");

	return prev;
}

static __always_inline unsigned long
__xchg_u64_local(volatile void *p, unsigned long val)
{
	unsigned long prev;

	__asm__ __volatile__(
"1:	ldarx	%0,0,%2 \n"
	PPC405_ERR77(0,%2)
"	stdcx.	%3,0,%2 \n\
	bne-	1b"
	: "=&r" (prev), "+m" (*(volatile unsigned long *)p)
	: "r" (p), "r" (val)
	: "cc", "memory");

	return prev;
}
#endif

/*
 * This function doesn't exist, so you'll get a linker error
 * if something tries to do an invalid xchg().
 */
extern void __xchg_called_with_bad_pointer(void);

static __always_inline unsigned long
__xchg(volatile void *ptr, unsigned long x, unsigned int size)
{
	switch (size) {
	case 4:
		return __xchg_u32(ptr, x);
#ifdef CONFIG_PPC64
	case 8:
		return __xchg_u64(ptr, x);
#endif
	}
	__xchg_called_with_bad_pointer();
	return x;
}

static __always_inline unsigned long
__xchg_local(volatile void *ptr, unsigned long x, unsigned int size)
{
	switch (size) {
	case 4:
		return __xchg_u32_local(ptr, x);
#ifdef CONFIG_PPC64
	case 8:
		return __xchg_u64_local(ptr, x);
#endif
	}
	__xchg_called_with_bad_pointer();
	return x;
}
#define xchg(ptr,x)							     \
  ({									     \
     __typeof__(*(ptr)) _x_ = (x);					     \
     (__typeof__(*(ptr))) __xchg((ptr), (unsigned long)_x_, sizeof(*(ptr))); \
  })

#define xchg_local(ptr,x)						     \
  ({									     \
     __typeof__(*(ptr)) _x_ = (x);					     \
     (__typeof__(*(ptr))) __xchg_local((ptr),				     \
     		(unsigned long)_x_, sizeof(*(ptr))); 			     \
  })

/*
 * Compare and exchange - if *p == old, set it to new,
 * and return the old value of *p.
 */

static __always_inline unsigned long
__cmpxchg_u32(volatile unsigned int *p, unsigned long old, unsigned long new)
{
	unsigned int prev;

	__asm__ __volatile__ (
	PPC_ATOMIC_ENTRY_BARRIER
"1:	lwarx	%0,0,%2		# __cmpxchg_u32\n\
	cmpw	0,%0,%3\n\
	bne-	2f\n"
	PPC405_ERR77(0,%2)
"	stwcx.	%4,0,%2\n\
	bne-	1b"
	PPC_ATOMIC_EXIT_BARRIER
	"\n\
2:"
	: "=&r" (prev), "+m" (*p)
	: "r" (p), "r" (old), "r" (new)
	: "cc", "memory");

	return prev;
}

static __always_inline unsigned long
__cmpxchg_u32_local(volatile unsigned int *p, unsigned long old,
			unsigned long new)
{
	unsigned int prev;

	__asm__ __volatile__ (
"1:	lwarx	%0,0,%2		# __cmpxchg_u32\n\
	cmpw	0,%0,%3\n\
	bne-	2f\n"
	PPC405_ERR77(0,%2)
"	stwcx.	%4,0,%2\n\
	bne-	1b"
	"\n\
2:"
	: "=&r" (prev), "+m" (*p)
	: "r" (p), "r" (old), "r" (new)
	: "cc", "memory");

	return prev;
}

#ifdef CONFIG_PPC64
static __always_inline unsigned long
__cmpxchg_u64(volatile unsigned long *p, unsigned long old, unsigned long new)
{
	unsigned long prev;

	__asm__ __volatile__ (
	PPC_ATOMIC_ENTRY_BARRIER
"1:	ldarx	%0,0,%2		# __cmpxchg_u64\n\
	cmpd	0,%0,%3\n\
	bne-	2f\n\
	stdcx.	%4,0,%2\n\
	bne-	1b"
	PPC_ATOMIC_EXIT_BARRIER
	"\n\
2:"
	: "=&r" (prev), "+m" (*p)
	: "r" (p), "r" (old), "r" (new)
	: "cc", "memory");

	return prev;
}

static __always_inline unsigned long
__cmpxchg_u64_local(volatile unsigned long *p, unsigned long old,
			unsigned long new)
{
	unsigned long prev;

	__asm__ __volatile__ (
"1:	ldarx	%0,0,%2		# __cmpxchg_u64\n\
	cmpd	0,%0,%3\n\
	bne-	2f\n\
	stdcx.	%4,0,%2\n\
	bne-	1b"
	"\n\
2:"
	: "=&r" (prev), "+m" (*p)
	: "r" (p), "r" (old), "r" (new)
	: "cc", "memory");

	return prev;
}
#endif

/* This function doesn't exist, so you'll get a linker error
   if something tries to do an invalid cmpxchg().  */
extern void __cmpxchg_called_with_bad_pointer(void);

static __always_inline unsigned long
__cmpxchg(volatile void *ptr, unsigned long old, unsigned long new,
	  unsigned int size)
{
	switch (size) {
	case 4:
		return __cmpxchg_u32(ptr, old, new);
#ifdef CONFIG_PPC64
	case 8:
		return __cmpxchg_u64(ptr, old, new);
#endif
	}
	__cmpxchg_called_with_bad_pointer();
	return old;
}

static __always_inline unsigned long
__cmpxchg_local(volatile void *ptr, unsigned long old, unsigned long new,
	  unsigned int size)
{
	switch (size) {
	case 4:
		return __cmpxchg_u32_local(ptr, old, new);
#ifdef CONFIG_PPC64
	case 8:
		return __cmpxchg_u64_local(ptr, old, new);
#endif
	}
	__cmpxchg_called_with_bad_pointer();
	return old;
}

#define cmpxchg(ptr, o, n)						 \
  ({									 \
     __typeof__(*(ptr)) _o_ = (o);					 \
     __typeof__(*(ptr)) _n_ = (n);					 \
     (__typeof__(*(ptr))) __cmpxchg((ptr), (unsigned long)_o_,		 \
				    (unsigned long)_n_, sizeof(*(ptr))); \
  })


#define cmpxchg_local(ptr, o, n)					 \
  ({									 \
     __typeof__(*(ptr)) _o_ = (o);					 \
     __typeof__(*(ptr)) _n_ = (n);					 \
     (__typeof__(*(ptr))) __cmpxchg_local((ptr), (unsigned long)_o_,	 \
				    (unsigned long)_n_, sizeof(*(ptr))); \
  })

#ifdef CONFIG_PPC64
#define cmpxchg64(ptr, o, n)						\
  ({									\
	BUILD_BUG_ON(sizeof(*(ptr)) != 8);				\
	cmpxchg((ptr), (o), (n));					\
  })
#define cmpxchg64_local(ptr, o, n)					\
  ({									\
	BUILD_BUG_ON(sizeof(*(ptr)) != 8);				\
	cmpxchg_local((ptr), (o), (n));					\
  })
#define cmpxchg64_relaxed	cmpxchg64_local
#else
#include <asm-generic/cmpxchg-local.h>
#define cmpxchg64_local(ptr, o, n) __cmpxchg64_local_generic((ptr), (o), (n))
#endif

#endif /* __KERNEL__ */
#endif /* _ASM_POWERPC_CMPXCHG_H_ */