xref: /openbmc/linux/arch/parisc/include/asm/atomic.h (revision 657c45b3)
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