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_INIT(i) { (i) }
20
21 #define atomic_read(v) READ_ONCE((v)->counter)
22 #define atomic_set(v, i) WRITE_ONCE(((v)->counter), (i))
23
24 /*
25 * The ColdFire parts cannot do some immediate to memory operations,
26 * so for them we do not specify the "i" asm constraint.
27 */
28 #ifdef CONFIG_COLDFIRE
29 #define ASM_DI "d"
30 #else
31 #define ASM_DI "di"
32 #endif
33
34 #define ATOMIC_OP(op, c_op, asm_op) \
35 static inline void atomic_##op(int i, atomic_t *v) \
36 { \
37 __asm__ __volatile__(#asm_op "l %1,%0" : "+m" (*v) : ASM_DI (i));\
38 } \
39
40 #ifdef CONFIG_RMW_INSNS
41
42 #define ATOMIC_OP_RETURN(op, c_op, asm_op) \
43 static inline int atomic_##op##_return(int i, atomic_t *v) \
44 { \
45 int t, tmp; \
46 \
47 __asm__ __volatile__( \
48 "1: movel %2,%1\n" \
49 " " #asm_op "l %3,%1\n" \
50 " casl %2,%1,%0\n" \
51 " jne 1b" \
52 : "+m" (*v), "=&d" (t), "=&d" (tmp) \
53 : "g" (i), "2" (atomic_read(v))); \
54 return t; \
55 }
56
57 #define ATOMIC_FETCH_OP(op, c_op, asm_op) \
58 static inline int atomic_fetch_##op(int i, atomic_t *v) \
59 { \
60 int t, tmp; \
61 \
62 __asm__ __volatile__( \
63 "1: movel %2,%1\n" \
64 " " #asm_op "l %3,%1\n" \
65 " casl %2,%1,%0\n" \
66 " jne 1b" \
67 : "+m" (*v), "=&d" (t), "=&d" (tmp) \
68 : "g" (i), "2" (atomic_read(v))); \
69 return tmp; \
70 }
71
72 #else
73
74 #define ATOMIC_OP_RETURN(op, c_op, asm_op) \
75 static inline int atomic_##op##_return(int i, atomic_t * v) \
76 { \
77 unsigned long flags; \
78 int t; \
79 \
80 local_irq_save(flags); \
81 t = (v->counter c_op i); \
82 local_irq_restore(flags); \
83 \
84 return t; \
85 }
86
87 #define ATOMIC_FETCH_OP(op, c_op, asm_op) \
88 static inline int atomic_fetch_##op(int i, atomic_t * v) \
89 { \
90 unsigned long flags; \
91 int t; \
92 \
93 local_irq_save(flags); \
94 t = v->counter; \
95 v->counter c_op i; \
96 local_irq_restore(flags); \
97 \
98 return t; \
99 }
100
101 #endif /* CONFIG_RMW_INSNS */
102
103 #define ATOMIC_OPS(op, c_op, asm_op) \
104 ATOMIC_OP(op, c_op, asm_op) \
105 ATOMIC_OP_RETURN(op, c_op, asm_op) \
106 ATOMIC_FETCH_OP(op, c_op, asm_op)
107
108 ATOMIC_OPS(add, +=, add)
109 ATOMIC_OPS(sub, -=, sub)
110
111 #undef ATOMIC_OPS
112 #define ATOMIC_OPS(op, c_op, asm_op) \
113 ATOMIC_OP(op, c_op, asm_op) \
114 ATOMIC_FETCH_OP(op, c_op, asm_op)
115
116 ATOMIC_OPS(and, &=, and)
117 ATOMIC_OPS(or, |=, or)
118 ATOMIC_OPS(xor, ^=, eor)
119
120 #undef ATOMIC_OPS
121 #undef ATOMIC_FETCH_OP
122 #undef ATOMIC_OP_RETURN
123 #undef ATOMIC_OP
124
atomic_inc(atomic_t * v)125 static inline void atomic_inc(atomic_t *v)
126 {
127 __asm__ __volatile__("addql #1,%0" : "+m" (*v));
128 }
129 #define atomic_inc atomic_inc
130
atomic_dec(atomic_t * v)131 static inline void atomic_dec(atomic_t *v)
132 {
133 __asm__ __volatile__("subql #1,%0" : "+m" (*v));
134 }
135 #define atomic_dec atomic_dec
136
atomic_dec_and_test(atomic_t * v)137 static inline int atomic_dec_and_test(atomic_t *v)
138 {
139 char c;
140 __asm__ __volatile__("subql #1,%1; seq %0" : "=d" (c), "+m" (*v));
141 return c != 0;
142 }
143 #define atomic_dec_and_test atomic_dec_and_test
144
atomic_dec_and_test_lt(atomic_t * v)145 static inline int atomic_dec_and_test_lt(atomic_t *v)
146 {
147 char c;
148 __asm__ __volatile__(
149 "subql #1,%1; slt %0"
150 : "=d" (c), "=m" (*v)
151 : "m" (*v));
152 return c != 0;
153 }
154
atomic_inc_and_test(atomic_t * v)155 static inline int atomic_inc_and_test(atomic_t *v)
156 {
157 char c;
158 __asm__ __volatile__("addql #1,%1; seq %0" : "=d" (c), "+m" (*v));
159 return c != 0;
160 }
161 #define atomic_inc_and_test atomic_inc_and_test
162
163 #ifdef CONFIG_RMW_INSNS
164
165 #define atomic_cmpxchg(v, o, n) ((int)cmpxchg(&((v)->counter), (o), (n)))
166 #define atomic_xchg(v, new) (xchg(&((v)->counter), new))
167
168 #else /* !CONFIG_RMW_INSNS */
169
atomic_cmpxchg(atomic_t * v,int old,int new)170 static inline int atomic_cmpxchg(atomic_t *v, int old, int new)
171 {
172 unsigned long flags;
173 int prev;
174
175 local_irq_save(flags);
176 prev = atomic_read(v);
177 if (prev == old)
178 atomic_set(v, new);
179 local_irq_restore(flags);
180 return prev;
181 }
182
atomic_xchg(atomic_t * v,int new)183 static inline int atomic_xchg(atomic_t *v, int new)
184 {
185 unsigned long flags;
186 int prev;
187
188 local_irq_save(flags);
189 prev = atomic_read(v);
190 atomic_set(v, new);
191 local_irq_restore(flags);
192 return prev;
193 }
194
195 #endif /* !CONFIG_RMW_INSNS */
196
atomic_sub_and_test(int i,atomic_t * v)197 static inline int atomic_sub_and_test(int i, atomic_t *v)
198 {
199 char c;
200 __asm__ __volatile__("subl %2,%1; seq %0"
201 : "=d" (c), "+m" (*v)
202 : ASM_DI (i));
203 return c != 0;
204 }
205 #define atomic_sub_and_test atomic_sub_and_test
206
atomic_add_negative(int i,atomic_t * v)207 static inline int atomic_add_negative(int i, atomic_t *v)
208 {
209 char c;
210 __asm__ __volatile__("addl %2,%1; smi %0"
211 : "=d" (c), "+m" (*v)
212 : ASM_DI (i));
213 return c != 0;
214 }
215 #define atomic_add_negative atomic_add_negative
216
217 #endif /* __ARCH_M68K_ATOMIC __ */
218