1 /* SPDX-License-Identifier: GPL-2.0 */
2 /* Copyright (C) 2000 Philipp Rumpf <prumpf@tux.org>
3 * Copyright (C) 2006 Kyle McMartin <kyle@parisc-linux.org>
4 */
5
6 #ifndef _ASM_PARISC_ATOMIC_H_
7 #define _ASM_PARISC_ATOMIC_H_
8
9 #include <linux/types.h>
10 #include <asm/cmpxchg.h>
11 #include <asm/barrier.h>
12
13 /*
14 * Atomic operations that C can't guarantee us. Useful for
15 * resource counting etc..
16 *
17 * And probably incredibly slow on parisc. OTOH, we don't
18 * have to write any serious assembly. prumpf
19 */
20
21 #ifdef CONFIG_SMP
22 #include <asm/spinlock.h>
23 #include <asm/cache.h> /* we use L1_CACHE_BYTES */
24
25 /* Use an array of spinlocks for our atomic_ts.
26 * Hash function to index into a different SPINLOCK.
27 * Since "a" is usually an address, use one spinlock per cacheline.
28 */
29 # define ATOMIC_HASH_SIZE 4
30 # define ATOMIC_HASH(a) (&(__atomic_hash[ (((unsigned long) (a))/L1_CACHE_BYTES) & (ATOMIC_HASH_SIZE-1) ]))
31
32 extern arch_spinlock_t __atomic_hash[ATOMIC_HASH_SIZE] __lock_aligned;
33
34 /* Can't use raw_spin_lock_irq because of #include problems, so
35 * this is the substitute */
36 #define _atomic_spin_lock_irqsave(l,f) do { \
37 arch_spinlock_t *s = ATOMIC_HASH(l); \
38 local_irq_save(f); \
39 arch_spin_lock(s); \
40 } while(0)
41
42 #define _atomic_spin_unlock_irqrestore(l,f) do { \
43 arch_spinlock_t *s = ATOMIC_HASH(l); \
44 arch_spin_unlock(s); \
45 local_irq_restore(f); \
46 } while(0)
47
48
49 #else
50 # define _atomic_spin_lock_irqsave(l,f) do { local_irq_save(f); } while (0)
51 # define _atomic_spin_unlock_irqrestore(l,f) do { local_irq_restore(f); } while (0)
52 #endif
53
54 /*
55 * Note that we need not lock read accesses - aligned word writes/reads
56 * are atomic, so a reader never sees inconsistent values.
57 */
58
59 static __inline__ void arch_atomic_set(atomic_t *v, int i)
60 {
61 unsigned long flags;
62 _atomic_spin_lock_irqsave(v, flags);
63
64 v->counter = i;
65
66 _atomic_spin_unlock_irqrestore(v, flags);
67 }
68
69 #define arch_atomic_set_release(v, i) arch_atomic_set((v), (i))
70
71 static __inline__ int arch_atomic_read(const atomic_t *v)
72 {
73 return READ_ONCE((v)->counter);
74 }
75
76 #define ATOMIC_OP(op, c_op) \
77 static __inline__ void arch_atomic_##op(int i, atomic_t *v) \
78 { \
79 unsigned long flags; \
80 \
81 _atomic_spin_lock_irqsave(v, flags); \
82 v->counter c_op i; \
83 _atomic_spin_unlock_irqrestore(v, flags); \
84 }
85
86 #define ATOMIC_OP_RETURN(op, c_op) \
87 static __inline__ int arch_atomic_##op##_return(int i, atomic_t *v) \
88 { \
89 unsigned long flags; \
90 int ret; \
91 \
92 _atomic_spin_lock_irqsave(v, flags); \
93 ret = (v->counter c_op i); \
94 _atomic_spin_unlock_irqrestore(v, flags); \
95 \
96 return ret; \
97 }
98
99 #define ATOMIC_FETCH_OP(op, c_op) \
100 static __inline__ int arch_atomic_fetch_##op(int i, atomic_t *v) \
101 { \
102 unsigned long flags; \
103 int ret; \
104 \
105 _atomic_spin_lock_irqsave(v, flags); \
106 ret = v->counter; \
107 v->counter c_op i; \
108 _atomic_spin_unlock_irqrestore(v, flags); \
109 \
110 return ret; \
111 }
112
113 #define ATOMIC_OPS(op, c_op) \
114 ATOMIC_OP(op, c_op) \
115 ATOMIC_OP_RETURN(op, c_op) \
116 ATOMIC_FETCH_OP(op, c_op)
117
118 ATOMIC_OPS(add, +=)
119 ATOMIC_OPS(sub, -=)
120
121 #define arch_atomic_add_return arch_atomic_add_return
122 #define arch_atomic_sub_return arch_atomic_sub_return
123 #define arch_atomic_fetch_add arch_atomic_fetch_add
124 #define arch_atomic_fetch_sub arch_atomic_fetch_sub
125
126 #undef ATOMIC_OPS
127 #define ATOMIC_OPS(op, c_op) \
128 ATOMIC_OP(op, c_op) \
129 ATOMIC_FETCH_OP(op, c_op)
130
131 ATOMIC_OPS(and, &=)
132 ATOMIC_OPS(or, |=)
133 ATOMIC_OPS(xor, ^=)
134
135 #define arch_atomic_fetch_and arch_atomic_fetch_and
136 #define arch_atomic_fetch_or arch_atomic_fetch_or
137 #define arch_atomic_fetch_xor arch_atomic_fetch_xor
138
139 #undef ATOMIC_OPS
140 #undef ATOMIC_FETCH_OP
141 #undef ATOMIC_OP_RETURN
142 #undef ATOMIC_OP
143
144 #ifdef CONFIG_64BIT
145
146 #define ATOMIC64_INIT(i) { (i) }
147
148 #define ATOMIC64_OP(op, c_op) \
149 static __inline__ void arch_atomic64_##op(s64 i, atomic64_t *v) \
150 { \
151 unsigned long flags; \
152 \
153 _atomic_spin_lock_irqsave(v, flags); \
154 v->counter c_op i; \
155 _atomic_spin_unlock_irqrestore(v, flags); \
156 }
157
158 #define ATOMIC64_OP_RETURN(op, c_op) \
159 static __inline__ s64 arch_atomic64_##op##_return(s64 i, atomic64_t *v) \
160 { \
161 unsigned long flags; \
162 s64 ret; \
163 \
164 _atomic_spin_lock_irqsave(v, flags); \
165 ret = (v->counter c_op i); \
166 _atomic_spin_unlock_irqrestore(v, flags); \
167 \
168 return ret; \
169 }
170
171 #define ATOMIC64_FETCH_OP(op, c_op) \
172 static __inline__ s64 arch_atomic64_fetch_##op(s64 i, atomic64_t *v) \
173 { \
174 unsigned long flags; \
175 s64 ret; \
176 \
177 _atomic_spin_lock_irqsave(v, flags); \
178 ret = v->counter; \
179 v->counter c_op i; \
180 _atomic_spin_unlock_irqrestore(v, flags); \
181 \
182 return ret; \
183 }
184
185 #define ATOMIC64_OPS(op, c_op) \
186 ATOMIC64_OP(op, c_op) \
187 ATOMIC64_OP_RETURN(op, c_op) \
188 ATOMIC64_FETCH_OP(op, c_op)
189
190 ATOMIC64_OPS(add, +=)
191 ATOMIC64_OPS(sub, -=)
192
193 #define arch_atomic64_add_return arch_atomic64_add_return
194 #define arch_atomic64_sub_return arch_atomic64_sub_return
195 #define arch_atomic64_fetch_add arch_atomic64_fetch_add
196 #define arch_atomic64_fetch_sub arch_atomic64_fetch_sub
197
198 #undef ATOMIC64_OPS
199 #define ATOMIC64_OPS(op, c_op) \
200 ATOMIC64_OP(op, c_op) \
201 ATOMIC64_FETCH_OP(op, c_op)
202
203 ATOMIC64_OPS(and, &=)
204 ATOMIC64_OPS(or, |=)
205 ATOMIC64_OPS(xor, ^=)
206
207 #define arch_atomic64_fetch_and arch_atomic64_fetch_and
208 #define arch_atomic64_fetch_or arch_atomic64_fetch_or
209 #define arch_atomic64_fetch_xor arch_atomic64_fetch_xor
210
211 #undef ATOMIC64_OPS
212 #undef ATOMIC64_FETCH_OP
213 #undef ATOMIC64_OP_RETURN
214 #undef ATOMIC64_OP
215
216 static __inline__ void
217 arch_atomic64_set(atomic64_t *v, s64 i)
218 {
219 unsigned long flags;
220 _atomic_spin_lock_irqsave(v, flags);
221
222 v->counter = i;
223
224 _atomic_spin_unlock_irqrestore(v, flags);
225 }
226
227 #define arch_atomic64_set_release(v, i) arch_atomic64_set((v), (i))
228
229 static __inline__ s64
230 arch_atomic64_read(const atomic64_t *v)
231 {
232 return READ_ONCE((v)->counter);
233 }
234
235 #endif /* !CONFIG_64BIT */
236
237
238 #endif /* _ASM_PARISC_ATOMIC_H_ */
239
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