summaryrefslogtreecommitdiffstats
path: root/arch/arm64/include/asm/cmpxchg.h
blob: d7a5407367414df69a898bef948f7c896778f38b (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
/* SPDX-License-Identifier: GPL-2.0-only */
/*
 * Based on arch/arm/include/asm/cmpxchg.h
 *
 * Copyright (C) 2012 ARM Ltd.
 */
#ifndef __ASM_CMPXCHG_H
#define __ASM_CMPXCHG_H

#include <linux/build_bug.h>
#include <linux/compiler.h>

#include <asm/barrier.h>
#include <asm/lse.h>

/*
 * We need separate acquire parameters for ll/sc and lse, since the full
 * barrier case is generated as release+dmb for the former and
 * acquire+release for the latter.
 */
#define __XCHG_CASE(w, sfx, name, sz, mb, nop_lse, acq, acq_lse, rel, cl)	\
static inline u##sz __xchg_case_##name##sz(u##sz x, volatile void *ptr)		\
{										\
	u##sz ret;								\
	unsigned long tmp;							\
										\
	asm volatile(ARM64_LSE_ATOMIC_INSN(					\
	/* LL/SC */								\
	"	prfm	pstl1strm, %2\n"					\
	"1:	ld" #acq "xr" #sfx "\t%" #w "0, %2\n"				\
	"	st" #rel "xr" #sfx "\t%w1, %" #w "3, %2\n"			\
	"	cbnz	%w1, 1b\n"						\
	"	" #mb,								\
	/* LSE atomics */							\
	"	swp" #acq_lse #rel #sfx "\t%" #w "3, %" #w "0, %2\n"		\
		__nops(3)							\
	"	" #nop_lse)							\
	: "=&r" (ret), "=&r" (tmp), "+Q" (*(u##sz *)ptr)			\
	: "r" (x)								\
	: cl);									\
										\
	return ret;								\
}

__XCHG_CASE(w, b,     ,  8,        ,    ,  ,  ,  ,         )
__XCHG_CASE(w, h,     , 16,        ,    ,  ,  ,  ,         )
__XCHG_CASE(w,  ,     , 32,        ,    ,  ,  ,  ,         )
__XCHG_CASE( ,  ,     , 64,        ,    ,  ,  ,  ,         )
__XCHG_CASE(w, b, acq_,  8,        ,    , a, a,  , "memory")
__XCHG_CASE(w, h, acq_, 16,        ,    , a, a,  , "memory")
__XCHG_CASE(w,  , acq_, 32,        ,    , a, a,  , "memory")
__XCHG_CASE( ,  , acq_, 64,        ,    , a, a,  , "memory")
__XCHG_CASE(w, b, rel_,  8,        ,    ,  ,  , l, "memory")
__XCHG_CASE(w, h, rel_, 16,        ,    ,  ,  , l, "memory")
__XCHG_CASE(w,  , rel_, 32,        ,    ,  ,  , l, "memory")
__XCHG_CASE( ,  , rel_, 64,        ,    ,  ,  , l, "memory")
__XCHG_CASE(w, b,  mb_,  8, dmb ish, nop,  , a, l, "memory")
__XCHG_CASE(w, h,  mb_, 16, dmb ish, nop,  , a, l, "memory")
__XCHG_CASE(w,  ,  mb_, 32, dmb ish, nop,  , a, l, "memory")
__XCHG_CASE( ,  ,  mb_, 64, dmb ish, nop,  , a, l, "memory")

#undef __XCHG_CASE

#define __XCHG_GEN(sfx)							\
static __always_inline unsigned long					\
__arch_xchg##sfx(unsigned long x, volatile void *ptr, int size)		\
{									\
	switch (size) {							\
	case 1:								\
		return __xchg_case##sfx##_8(x, ptr);			\
	case 2:								\
		return __xchg_case##sfx##_16(x, ptr);			\
	case 4:								\
		return __xchg_case##sfx##_32(x, ptr);			\
	case 8:								\
		return __xchg_case##sfx##_64(x, ptr);			\
	default:							\
		BUILD_BUG();						\
	}								\
									\
	unreachable();							\
}

__XCHG_GEN()
__XCHG_GEN(_acq)
__XCHG_GEN(_rel)
__XCHG_GEN(_mb)

#undef __XCHG_GEN

#define __xchg_wrapper(sfx, ptr, x)					\
({									\
	__typeof__(*(ptr)) __ret;					\
	__ret = (__typeof__(*(ptr)))					\
		__arch_xchg##sfx((unsigned long)(x), (ptr), sizeof(*(ptr))); \
	__ret;								\
})

/* xchg */
#define arch_xchg_relaxed(...)	__xchg_wrapper(    , __VA_ARGS__)
#define arch_xchg_acquire(...)	__xchg_wrapper(_acq, __VA_ARGS__)
#define arch_xchg_release(...)	__xchg_wrapper(_rel, __VA_ARGS__)
#define arch_xchg(...)		__xchg_wrapper( _mb, __VA_ARGS__)

#define __CMPXCHG_CASE(name, sz)			\
static inline u##sz __cmpxchg_case_##name##sz(volatile void *ptr,	\
					      u##sz old,		\
					      u##sz new)		\
{									\
	return __lse_ll_sc_body(_cmpxchg_case_##name##sz,		\
				ptr, old, new);				\
}

__CMPXCHG_CASE(    ,  8)
__CMPXCHG_CASE(    , 16)
__CMPXCHG_CASE(    , 32)
__CMPXCHG_CASE(    , 64)
__CMPXCHG_CASE(acq_,  8)
__CMPXCHG_CASE(acq_, 16)
__CMPXCHG_CASE(acq_, 32)
__CMPXCHG_CASE(acq_, 64)
__CMPXCHG_CASE(rel_,  8)
__CMPXCHG_CASE(rel_, 16)
__CMPXCHG_CASE(rel_, 32)
__CMPXCHG_CASE(rel_, 64)
__CMPXCHG_CASE(mb_,  8)
__CMPXCHG_CASE(mb_, 16)
__CMPXCHG_CASE(mb_, 32)
__CMPXCHG_CASE(mb_, 64)

#undef __CMPXCHG_CASE

#define __CMPXCHG128(name)						\
static inline u128 __cmpxchg128##name(volatile u128 *ptr,		\
				      u128 old, u128 new)		\
{									\
	return __lse_ll_sc_body(_cmpxchg128##name,			\
				ptr, old, new);				\
}

__CMPXCHG128(   )
__CMPXCHG128(_mb)

#undef __CMPXCHG128

#define __CMPXCHG_GEN(sfx)						\
static __always_inline unsigned long __cmpxchg##sfx(volatile void *ptr,	\
					   unsigned long old,		\
					   unsigned long new,		\
					   int size)			\
{									\
	switch (size) {							\
	case 1:								\
		return __cmpxchg_case##sfx##_8(ptr, old, new);		\
	case 2:								\
		return __cmpxchg_case##sfx##_16(ptr, old, new);		\
	case 4:								\
		return __cmpxchg_case##sfx##_32(ptr, old, new);		\
	case 8:								\
		return __cmpxchg_case##sfx##_64(ptr, old, new);		\
	default:							\
		BUILD_BUG();						\
	}								\
									\
	unreachable();							\
}

__CMPXCHG_GEN()
__CMPXCHG_GEN(_acq)
__CMPXCHG_GEN(_rel)
__CMPXCHG_GEN(_mb)

#undef __CMPXCHG_GEN

#define __cmpxchg_wrapper(sfx, ptr, o, n)				\
({									\
	__typeof__(*(ptr)) __ret;					\
	__ret = (__typeof__(*(ptr)))					\
		__cmpxchg##sfx((ptr), (unsigned long)(o),		\
				(unsigned long)(n), sizeof(*(ptr)));	\
	__ret;								\
})

/* cmpxchg */
#define arch_cmpxchg_relaxed(...)	__cmpxchg_wrapper(    , __VA_ARGS__)
#define arch_cmpxchg_acquire(...)	__cmpxchg_wrapper(_acq, __VA_ARGS__)
#define arch_cmpxchg_release(...)	__cmpxchg_wrapper(_rel, __VA_ARGS__)
#define arch_cmpxchg(...)		__cmpxchg_wrapper( _mb, __VA_ARGS__)
#define arch_cmpxchg_local		arch_cmpxchg_relaxed

/* cmpxchg64 */
#define arch_cmpxchg64_relaxed		arch_cmpxchg_relaxed
#define arch_cmpxchg64_acquire		arch_cmpxchg_acquire
#define arch_cmpxchg64_release		arch_cmpxchg_release
#define arch_cmpxchg64			arch_cmpxchg
#define arch_cmpxchg64_local		arch_cmpxchg_local

/* cmpxchg128 */
#define system_has_cmpxchg128()		1

#define arch_cmpxchg128(ptr, o, n)						\
({										\
	__cmpxchg128_mb((ptr), (o), (n));					\
})

#define arch_cmpxchg128_local(ptr, o, n)					\
({										\
	__cmpxchg128((ptr), (o), (n));						\
})

#define __CMPWAIT_CASE(w, sfx, sz)					\
static inline void __cmpwait_case_##sz(volatile void *ptr,		\
				       unsigned long val)		\
{									\
	unsigned long tmp;						\
									\
	asm volatile(							\
	"	sevl\n"							\
	"	wfe\n"							\
	"	ldxr" #sfx "\t%" #w "[tmp], %[v]\n"			\
	"	eor	%" #w "[tmp], %" #w "[tmp], %" #w "[val]\n"	\
	"	cbnz	%" #w "[tmp], 1f\n"				\
	"	wfe\n"							\
	"1:"								\
	: [tmp] "=&r" (tmp), [v] "+Q" (*(u##sz *)ptr)			\
	: [val] "r" (val));						\
}

__CMPWAIT_CASE(w, b, 8);
__CMPWAIT_CASE(w, h, 16);
__CMPWAIT_CASE(w,  , 32);
__CMPWAIT_CASE( ,  , 64);

#undef __CMPWAIT_CASE

#define __CMPWAIT_GEN(sfx)						\
static __always_inline void __cmpwait##sfx(volatile void *ptr,		\
				  unsigned long val,			\
				  int size)				\
{									\
	switch (size) {							\
	case 1:								\
		return __cmpwait_case##sfx##_8(ptr, (u8)val);		\
	case 2:								\
		return __cmpwait_case##sfx##_16(ptr, (u16)val);		\
	case 4:								\
		return __cmpwait_case##sfx##_32(ptr, val);		\
	case 8:								\
		return __cmpwait_case##sfx##_64(ptr, val);		\
	default:							\
		BUILD_BUG();						\
	}								\
									\
	unreachable();							\
}

__CMPWAIT_GEN()

#undef __CMPWAIT_GEN

#define __cmpwait_relaxed(ptr, val) \
	__cmpwait((ptr), (unsigned long)(val), sizeof(*(ptr)))

#endif	/* __ASM_CMPXCHG_H */