xref: /openbmc/linux/arch/m68k/include/asm/atomic.h (revision 86e281fc)
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 arch_atomic_read(v)	READ_ONCE((v)->counter)
20 #define arch_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 arch_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 arch_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 			: "di" (i), "2" (arch_atomic_read(v)));		\
52 	return t;							\
53 }
54 
55 #define ATOMIC_FETCH_OP(op, c_op, asm_op)				\
56 static inline int arch_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 			: "di" (i), "2" (arch_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 arch_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 arch_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 #define arch_atomic_add_return			arch_atomic_add_return
110 #define arch_atomic_sub_return			arch_atomic_sub_return
111 #define arch_atomic_fetch_add			arch_atomic_fetch_add
112 #define arch_atomic_fetch_sub			arch_atomic_fetch_sub
113 
114 #undef ATOMIC_OPS
115 #define ATOMIC_OPS(op, c_op, asm_op)					\
116 	ATOMIC_OP(op, c_op, asm_op)					\
117 	ATOMIC_FETCH_OP(op, c_op, asm_op)
118 
119 ATOMIC_OPS(and, &=, and)
120 ATOMIC_OPS(or, |=, or)
121 ATOMIC_OPS(xor, ^=, eor)
122 
123 #define arch_atomic_fetch_and			arch_atomic_fetch_and
124 #define arch_atomic_fetch_or			arch_atomic_fetch_or
125 #define arch_atomic_fetch_xor			arch_atomic_fetch_xor
126 
127 #undef ATOMIC_OPS
128 #undef ATOMIC_FETCH_OP
129 #undef ATOMIC_OP_RETURN
130 #undef ATOMIC_OP
131 
132 static inline void arch_atomic_inc(atomic_t *v)
133 {
134 	__asm__ __volatile__("addql #1,%0" : "+m" (*v));
135 }
136 #define arch_atomic_inc arch_atomic_inc
137 
138 static inline void arch_atomic_dec(atomic_t *v)
139 {
140 	__asm__ __volatile__("subql #1,%0" : "+m" (*v));
141 }
142 #define arch_atomic_dec arch_atomic_dec
143 
144 static inline int arch_atomic_dec_and_test(atomic_t *v)
145 {
146 	char c;
147 	__asm__ __volatile__("subql #1,%1; seq %0" : "=d" (c), "+m" (*v));
148 	return c != 0;
149 }
150 #define arch_atomic_dec_and_test arch_atomic_dec_and_test
151 
152 static inline int arch_atomic_dec_and_test_lt(atomic_t *v)
153 {
154 	char c;
155 	__asm__ __volatile__(
156 		"subql #1,%1; slt %0"
157 		: "=d" (c), "=m" (*v)
158 		: "m" (*v));
159 	return c != 0;
160 }
161 
162 static inline int arch_atomic_inc_and_test(atomic_t *v)
163 {
164 	char c;
165 	__asm__ __volatile__("addql #1,%1; seq %0" : "=d" (c), "+m" (*v));
166 	return c != 0;
167 }
168 #define arch_atomic_inc_and_test arch_atomic_inc_and_test
169 
170 #ifndef CONFIG_RMW_INSNS
171 
172 static inline int arch_atomic_cmpxchg(atomic_t *v, int old, int new)
173 {
174 	unsigned long flags;
175 	int prev;
176 
177 	local_irq_save(flags);
178 	prev = arch_atomic_read(v);
179 	if (prev == old)
180 		arch_atomic_set(v, new);
181 	local_irq_restore(flags);
182 	return prev;
183 }
184 #define arch_atomic_cmpxchg arch_atomic_cmpxchg
185 
186 static inline int arch_atomic_xchg(atomic_t *v, int new)
187 {
188 	unsigned long flags;
189 	int prev;
190 
191 	local_irq_save(flags);
192 	prev = arch_atomic_read(v);
193 	arch_atomic_set(v, new);
194 	local_irq_restore(flags);
195 	return prev;
196 }
197 #define arch_atomic_xchg arch_atomic_xchg
198 
199 #endif /* !CONFIG_RMW_INSNS */
200 
201 static inline int arch_atomic_sub_and_test(int i, atomic_t *v)
202 {
203 	char c;
204 	__asm__ __volatile__("subl %2,%1; seq %0"
205 			     : "=d" (c), "+m" (*v)
206 			     : ASM_DI (i));
207 	return c != 0;
208 }
209 #define arch_atomic_sub_and_test arch_atomic_sub_and_test
210 
211 static inline int arch_atomic_add_negative(int i, atomic_t *v)
212 {
213 	char c;
214 	__asm__ __volatile__("addl %2,%1; smi %0"
215 			     : "=d" (c), "+m" (*v)
216 			     : ASM_DI (i));
217 	return c != 0;
218 }
219 #define arch_atomic_add_negative arch_atomic_add_negative
220 
221 #endif /* __ARCH_M68K_ATOMIC __ */
222