xref: /linux/arch/m68k/include/asm/atomic.h (revision 0d3b051adbb72ed81956447d0d1e54d5943ee6f5)
1 /* SPDX-License-Identifier: GPL-2.0 */
2 #ifndef __ARCH_M68K_ATOMIC__
3 #define __ARCH_M68K_ATOMIC__
4 
5 #include <linux/types.h>
6 #include <linux/irqflags.h>
7 #include <asm/cmpxchg.h>
8 #include <asm/barrier.h>
9 
10 /*
11  * Atomic operations that C can't guarantee us.  Useful for
12  * resource counting etc..
13  */
14 
15 /*
16  * We do not have SMP m68k systems, so we don't have to deal with that.
17  */
18 
19 #define atomic_read(v)		READ_ONCE((v)->counter)
20 #define atomic_set(v, i)	WRITE_ONCE(((v)->counter), (i))
21 
22 /*
23  * The ColdFire parts cannot do some immediate to memory operations,
24  * so for them we do not specify the "i" asm constraint.
25  */
26 #ifdef CONFIG_COLDFIRE
27 #define	ASM_DI	"d"
28 #else
29 #define	ASM_DI	"di"
30 #endif
31 
32 #define ATOMIC_OP(op, c_op, asm_op)					\
33 static inline void atomic_##op(int i, atomic_t *v)			\
34 {									\
35 	__asm__ __volatile__(#asm_op "l %1,%0" : "+m" (*v) : ASM_DI (i));\
36 }									\
37 
38 #ifdef CONFIG_RMW_INSNS
39 
40 #define ATOMIC_OP_RETURN(op, c_op, asm_op)				\
41 static inline int atomic_##op##_return(int i, atomic_t *v)		\
42 {									\
43 	int t, tmp;							\
44 									\
45 	__asm__ __volatile__(						\
46 			"1:	movel %2,%1\n"				\
47 			"	" #asm_op "l %3,%1\n"			\
48 			"	casl %2,%1,%0\n"			\
49 			"	jne 1b"					\
50 			: "+m" (*v), "=&d" (t), "=&d" (tmp)		\
51 			: "g" (i), "2" (atomic_read(v)));		\
52 	return t;							\
53 }
54 
55 #define ATOMIC_FETCH_OP(op, c_op, asm_op)				\
56 static inline int atomic_fetch_##op(int i, atomic_t *v)			\
57 {									\
58 	int t, tmp;							\
59 									\
60 	__asm__ __volatile__(						\
61 			"1:	movel %2,%1\n"				\
62 			"	" #asm_op "l %3,%1\n"			\
63 			"	casl %2,%1,%0\n"			\
64 			"	jne 1b"					\
65 			: "+m" (*v), "=&d" (t), "=&d" (tmp)		\
66 			: "g" (i), "2" (atomic_read(v)));		\
67 	return tmp;							\
68 }
69 
70 #else
71 
72 #define ATOMIC_OP_RETURN(op, c_op, asm_op)				\
73 static inline int atomic_##op##_return(int i, atomic_t * v)		\
74 {									\
75 	unsigned long flags;						\
76 	int t;								\
77 									\
78 	local_irq_save(flags);						\
79 	t = (v->counter c_op i);					\
80 	local_irq_restore(flags);					\
81 									\
82 	return t;							\
83 }
84 
85 #define ATOMIC_FETCH_OP(op, c_op, asm_op)				\
86 static inline int atomic_fetch_##op(int i, atomic_t * v)		\
87 {									\
88 	unsigned long flags;						\
89 	int t;								\
90 									\
91 	local_irq_save(flags);						\
92 	t = v->counter;							\
93 	v->counter c_op i;						\
94 	local_irq_restore(flags);					\
95 									\
96 	return t;							\
97 }
98 
99 #endif /* CONFIG_RMW_INSNS */
100 
101 #define ATOMIC_OPS(op, c_op, asm_op)					\
102 	ATOMIC_OP(op, c_op, asm_op)					\
103 	ATOMIC_OP_RETURN(op, c_op, asm_op)				\
104 	ATOMIC_FETCH_OP(op, c_op, asm_op)
105 
106 ATOMIC_OPS(add, +=, add)
107 ATOMIC_OPS(sub, -=, sub)
108 
109 #undef ATOMIC_OPS
110 #define ATOMIC_OPS(op, c_op, asm_op)					\
111 	ATOMIC_OP(op, c_op, asm_op)					\
112 	ATOMIC_FETCH_OP(op, c_op, asm_op)
113 
114 ATOMIC_OPS(and, &=, and)
115 ATOMIC_OPS(or, |=, or)
116 ATOMIC_OPS(xor, ^=, eor)
117 
118 #undef ATOMIC_OPS
119 #undef ATOMIC_FETCH_OP
120 #undef ATOMIC_OP_RETURN
121 #undef ATOMIC_OP
122 
123 static inline void atomic_inc(atomic_t *v)
124 {
125 	__asm__ __volatile__("addql #1,%0" : "+m" (*v));
126 }
127 #define atomic_inc atomic_inc
128 
129 static inline void atomic_dec(atomic_t *v)
130 {
131 	__asm__ __volatile__("subql #1,%0" : "+m" (*v));
132 }
133 #define atomic_dec atomic_dec
134 
135 static inline int atomic_dec_and_test(atomic_t *v)
136 {
137 	char c;
138 	__asm__ __volatile__("subql #1,%1; seq %0" : "=d" (c), "+m" (*v));
139 	return c != 0;
140 }
141 #define atomic_dec_and_test atomic_dec_and_test
142 
143 static inline int atomic_dec_and_test_lt(atomic_t *v)
144 {
145 	char c;
146 	__asm__ __volatile__(
147 		"subql #1,%1; slt %0"
148 		: "=d" (c), "=m" (*v)
149 		: "m" (*v));
150 	return c != 0;
151 }
152 
153 static inline int atomic_inc_and_test(atomic_t *v)
154 {
155 	char c;
156 	__asm__ __volatile__("addql #1,%1; seq %0" : "=d" (c), "+m" (*v));
157 	return c != 0;
158 }
159 #define atomic_inc_and_test atomic_inc_and_test
160 
161 #ifdef CONFIG_RMW_INSNS
162 
163 #define atomic_cmpxchg(v, o, n) ((int)cmpxchg(&((v)->counter), (o), (n)))
164 #define atomic_xchg(v, new) (xchg(&((v)->counter), new))
165 
166 #else /* !CONFIG_RMW_INSNS */
167 
168 static inline int atomic_cmpxchg(atomic_t *v, int old, int new)
169 {
170 	unsigned long flags;
171 	int prev;
172 
173 	local_irq_save(flags);
174 	prev = atomic_read(v);
175 	if (prev == old)
176 		atomic_set(v, new);
177 	local_irq_restore(flags);
178 	return prev;
179 }
180 
181 static inline int atomic_xchg(atomic_t *v, int new)
182 {
183 	unsigned long flags;
184 	int prev;
185 
186 	local_irq_save(flags);
187 	prev = atomic_read(v);
188 	atomic_set(v, new);
189 	local_irq_restore(flags);
190 	return prev;
191 }
192 
193 #endif /* !CONFIG_RMW_INSNS */
194 
195 static inline int atomic_sub_and_test(int i, atomic_t *v)
196 {
197 	char c;
198 	__asm__ __volatile__("subl %2,%1; seq %0"
199 			     : "=d" (c), "+m" (*v)
200 			     : ASM_DI (i));
201 	return c != 0;
202 }
203 #define atomic_sub_and_test atomic_sub_and_test
204 
205 static inline int atomic_add_negative(int i, atomic_t *v)
206 {
207 	char c;
208 	__asm__ __volatile__("addl %2,%1; smi %0"
209 			     : "=d" (c), "+m" (*v)
210 			     : ASM_DI (i));
211 	return c != 0;
212 }
213 #define atomic_add_negative atomic_add_negative
214 
215 #endif /* __ARCH_M68K_ATOMIC __ */
216