2 * Copyright 2011 Tilera Corporation. All Rights Reserved.
4 * This program is free software; you can redistribute it and/or
5 * modify it under the terms of the GNU General Public License
6 * as published by the Free Software Foundation, version 2.
8 * This program is distributed in the hope that it will be useful, but
9 * WITHOUT ANY WARRANTY; without even the implied warranty of
10 * MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE, GOOD TITLE or
11 * NON INFRINGEMENT. See the GNU General Public License for
14 * Do not include directly; use <linux/atomic.h>.
17 #ifndef _ASM_TILE_ATOMIC_64_H
18 #define _ASM_TILE_ATOMIC_64_H
22 #include <asm/barrier.h>
23 #include <arch/spr_def.h>
25 /* First, the 32-bit atomic ops that are "real" on our 64-bit platform. */
27 #define atomic_set(v, i) ((v)->counter = (i))
30 * The smp_mb() operations throughout are to support the fact that
31 * Linux requires memory barriers before and after the operation,
32 * on any routine which updates memory and returns a value.
35 static inline int atomic_cmpxchg(atomic_t *v, int o, int n)
38 __insn_mtspr(SPR_CMPEXCH_VALUE, o);
39 smp_mb(); /* barrier for proper semantics */
40 val = __insn_cmpexch4((void *)&v->counter, n);
41 smp_mb(); /* barrier for proper semantics */
45 static inline int atomic_xchg(atomic_t *v, int n)
48 smp_mb(); /* barrier for proper semantics */
49 val = __insn_exch4((void *)&v->counter, n);
50 smp_mb(); /* barrier for proper semantics */
54 static inline void atomic_add(int i, atomic_t *v)
56 __insn_fetchadd4((void *)&v->counter, i);
59 static inline int atomic_add_return(int i, atomic_t *v)
62 smp_mb(); /* barrier for proper semantics */
63 val = __insn_fetchadd4((void *)&v->counter, i) + i;
64 barrier(); /* the "+ i" above will wait on memory */
68 static inline int __atomic_add_unless(atomic_t *v, int a, int u)
70 int guess, oldval = v->counter;
75 oldval = atomic_cmpxchg(v, guess, guess + a);
76 } while (guess != oldval);
80 /* Now the true 64-bit operations. */
82 #define ATOMIC64_INIT(i) { (i) }
84 #define atomic64_read(v) ((v)->counter)
85 #define atomic64_set(v, i) ((v)->counter = (i))
87 static inline long atomic64_cmpxchg(atomic64_t *v, long o, long n)
90 smp_mb(); /* barrier for proper semantics */
91 __insn_mtspr(SPR_CMPEXCH_VALUE, o);
92 val = __insn_cmpexch((void *)&v->counter, n);
93 smp_mb(); /* barrier for proper semantics */
97 static inline long atomic64_xchg(atomic64_t *v, long n)
100 smp_mb(); /* barrier for proper semantics */
101 val = __insn_exch((void *)&v->counter, n);
102 smp_mb(); /* barrier for proper semantics */
106 static inline void atomic64_add(long i, atomic64_t *v)
108 __insn_fetchadd((void *)&v->counter, i);
111 static inline long atomic64_add_return(long i, atomic64_t *v)
114 smp_mb(); /* barrier for proper semantics */
115 val = __insn_fetchadd((void *)&v->counter, i) + i;
116 barrier(); /* the "+ i" above will wait on memory */
120 static inline long atomic64_add_unless(atomic64_t *v, long a, long u)
122 long guess, oldval = v->counter;
127 oldval = atomic64_cmpxchg(v, guess, guess + a);
128 } while (guess != oldval);
132 #define atomic64_sub_return(i, v) atomic64_add_return(-(i), (v))
133 #define atomic64_sub(i, v) atomic64_add(-(i), (v))
134 #define atomic64_inc_return(v) atomic64_add_return(1, (v))
135 #define atomic64_dec_return(v) atomic64_sub_return(1, (v))
136 #define atomic64_inc(v) atomic64_add(1, (v))
137 #define atomic64_dec(v) atomic64_sub(1, (v))
139 #define atomic64_inc_and_test(v) (atomic64_inc_return(v) == 0)
140 #define atomic64_dec_and_test(v) (atomic64_dec_return(v) == 0)
141 #define atomic64_sub_and_test(i, v) (atomic64_sub_return((i), (v)) == 0)
142 #define atomic64_add_negative(i, v) (atomic64_add_return((i), (v)) < 0)
144 #define atomic64_inc_not_zero(v) atomic64_add_unless((v), 1, 0)
146 /* Atomic dec and inc don't implement barrier, so provide them if needed. */
147 #define smp_mb__before_atomic_dec() smp_mb()
148 #define smp_mb__after_atomic_dec() smp_mb()
149 #define smp_mb__before_atomic_inc() smp_mb()
150 #define smp_mb__after_atomic_inc() smp_mb()
152 /* Define this to indicate that cmpxchg is an efficient operation. */
153 #define __HAVE_ARCH_CMPXCHG
155 #endif /* !__ASSEMBLY__ */
157 #endif /* _ASM_TILE_ATOMIC_64_H */