blob: 46d696b331e78b879cd0666fe516d060f61f856d [file] [log] [blame]
Linus Torvalds1da177e2005-04-16 15:20:36 -07001/* atomic.h: atomic operation emulation for FR-V
2 *
3 * For an explanation of how atomic ops work in this arch, see:
Adrian Bunk0868ff72008-02-03 15:54:28 +02004 * Documentation/frv/atomic-ops.txt
Linus Torvalds1da177e2005-04-16 15:20:36 -07005 *
6 * Copyright (C) 2004 Red Hat, Inc. All Rights Reserved.
7 * Written by David Howells (dhowells@redhat.com)
8 *
9 * This program is free software; you can redistribute it and/or
10 * modify it under the terms of the GNU General Public License
11 * as published by the Free Software Foundation; either version
12 * 2 of the License, or (at your option) any later version.
13 */
14#ifndef _ASM_ATOMIC_H
15#define _ASM_ATOMIC_H
16
Linus Torvalds1da177e2005-04-16 15:20:36 -070017#include <linux/types.h>
18#include <asm/spr-regs.h>
Mathieu Desnoyers2856f5e2007-05-08 00:34:38 -070019#include <asm/system.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070020
21#ifdef CONFIG_SMP
22#error not SMP safe
23#endif
24
25/*
26 * Atomic operations that C can't guarantee us. Useful for
27 * resource counting etc..
28 *
29 * We do not have SMP systems, so we don't have to deal with that.
30 */
31
32/* Atomic operations are already serializing */
33#define smp_mb__before_atomic_dec() barrier()
34#define smp_mb__after_atomic_dec() barrier()
35#define smp_mb__before_atomic_inc() barrier()
36#define smp_mb__after_atomic_inc() barrier()
37
38typedef struct {
39 int counter;
40} atomic_t;
41
42#define ATOMIC_INIT(i) { (i) }
43#define atomic_read(v) ((v)->counter)
44#define atomic_set(v, i) (((v)->counter) = (i))
45
46#ifndef CONFIG_FRV_OUTOFLINE_ATOMIC_OPS
47static inline int atomic_add_return(int i, atomic_t *v)
48{
49 unsigned long val;
50
51 asm("0: \n"
52 " orcc gr0,gr0,gr0,icc3 \n" /* set ICC3.Z */
53 " ckeq icc3,cc7 \n"
54 " ld.p %M0,%1 \n" /* LD.P/ORCR must be atomic */
55 " orcr cc7,cc7,cc3 \n" /* set CC3 to true */
56 " add%I2 %1,%2,%1 \n"
57 " cst.p %1,%M0 ,cc3,#1 \n"
58 " corcc gr29,gr29,gr0 ,cc3,#1 \n" /* clear ICC3.Z if store happens */
59 " beq icc3,#0,0b \n"
60 : "+U"(v->counter), "=&r"(val)
61 : "NPr"(i)
62 : "memory", "cc7", "cc3", "icc3"
63 );
64
65 return val;
66}
67
68static inline int atomic_sub_return(int i, atomic_t *v)
69{
70 unsigned long val;
71
72 asm("0: \n"
73 " orcc gr0,gr0,gr0,icc3 \n" /* set ICC3.Z */
74 " ckeq icc3,cc7 \n"
75 " ld.p %M0,%1 \n" /* LD.P/ORCR must be atomic */
76 " orcr cc7,cc7,cc3 \n" /* set CC3 to true */
77 " sub%I2 %1,%2,%1 \n"
78 " cst.p %1,%M0 ,cc3,#1 \n"
79 " corcc gr29,gr29,gr0 ,cc3,#1 \n" /* clear ICC3.Z if store happens */
80 " beq icc3,#0,0b \n"
81 : "+U"(v->counter), "=&r"(val)
82 : "NPr"(i)
83 : "memory", "cc7", "cc3", "icc3"
84 );
85
86 return val;
87}
88
89#else
90
91extern int atomic_add_return(int i, atomic_t *v);
92extern int atomic_sub_return(int i, atomic_t *v);
93
94#endif
95
96static inline int atomic_add_negative(int i, atomic_t *v)
97{
98 return atomic_add_return(i, v) < 0;
99}
100
101static inline void atomic_add(int i, atomic_t *v)
102{
103 atomic_add_return(i, v);
104}
105
106static inline void atomic_sub(int i, atomic_t *v)
107{
108 atomic_sub_return(i, v);
109}
110
111static inline void atomic_inc(atomic_t *v)
112{
113 atomic_add_return(1, v);
114}
115
116static inline void atomic_dec(atomic_t *v)
117{
118 atomic_sub_return(1, v);
119}
120
121#define atomic_dec_return(v) atomic_sub_return(1, (v))
122#define atomic_inc_return(v) atomic_add_return(1, (v))
123
124#define atomic_sub_and_test(i,v) (atomic_sub_return((i), (v)) == 0)
125#define atomic_dec_and_test(v) (atomic_sub_return(1, (v)) == 0)
126#define atomic_inc_and_test(v) (atomic_add_return(1, (v)) == 0)
127
Linus Torvalds1da177e2005-04-16 15:20:36 -0700128/*****************************************************************************/
129/*
130 * exchange value with memory
131 */
132#ifndef CONFIG_FRV_OUTOFLINE_ATOMIC_OPS
133
134#define xchg(ptr, x) \
135({ \
136 __typeof__(ptr) __xg_ptr = (ptr); \
137 __typeof__(*(ptr)) __xg_orig; \
138 \
139 switch (sizeof(__xg_orig)) { \
Linus Torvalds1da177e2005-04-16 15:20:36 -0700140 case 4: \
141 asm volatile( \
David Howells68f624f2006-02-14 13:53:18 -0800142 "swap%I0 %M0,%1" \
143 : "+m"(*__xg_ptr), "=r"(__xg_orig) \
144 : "1"(x) \
David Howells2fa9e7e2006-01-08 01:01:17 -0800145 : "memory" \
Linus Torvalds1da177e2005-04-16 15:20:36 -0700146 ); \
147 break; \
148 \
149 default: \
Al Viro7f788432006-06-23 02:04:09 -0700150 __xg_orig = (__typeof__(__xg_orig))0; \
Linus Torvalds1da177e2005-04-16 15:20:36 -0700151 asm volatile("break"); \
152 break; \
153 } \
154 \
155 __xg_orig; \
156})
157
158#else
159
Linus Torvalds1da177e2005-04-16 15:20:36 -0700160extern uint32_t __xchg_32(uint32_t i, volatile void *v);
161
162#define xchg(ptr, x) \
163({ \
164 __typeof__(ptr) __xg_ptr = (ptr); \
165 __typeof__(*(ptr)) __xg_orig; \
166 \
167 switch (sizeof(__xg_orig)) { \
Linus Torvalds1da177e2005-04-16 15:20:36 -0700168 case 4: __xg_orig = (__typeof__(*(ptr))) __xchg_32((uint32_t) x, __xg_ptr); break; \
169 default: \
Al Viro7f788432006-06-23 02:04:09 -0700170 __xg_orig = (__typeof__(__xg_orig))0; \
Linus Torvalds1da177e2005-04-16 15:20:36 -0700171 asm volatile("break"); \
172 break; \
173 } \
174 __xg_orig; \
175})
176
177#endif
178
179#define tas(ptr) (xchg((ptr), 1))
180
David Howells2fa9e7e2006-01-08 01:01:17 -0800181#define atomic_cmpxchg(v, old, new) (cmpxchg(&((v)->counter), old, new))
Ingo Molnarffbf6702006-01-09 15:59:17 -0800182#define atomic_xchg(v, new) (xchg(&((v)->counter), new))
Nick Piggin4a6dae62005-11-13 16:07:24 -0800183
Mathieu Desnoyers2856f5e2007-05-08 00:34:38 -0700184static __inline__ int atomic_add_unless(atomic_t *v, int a, int u)
185{
186 int c, old;
187 c = atomic_read(v);
188 for (;;) {
189 if (unlikely(c == (u)))
190 break;
191 old = atomic_cmpxchg((v), c, c + (a));
192 if (likely(old == c))
193 break;
194 c = old;
195 }
196 return c != (u);
197}
David Howells2fa9e7e2006-01-08 01:01:17 -0800198
Nick Piggin8426e1f2005-11-13 16:07:25 -0800199#define atomic_inc_not_zero(v) atomic_add_unless((v), 1, 0)
200
Christoph Lameterd3cb4872006-01-06 00:11:20 -0800201#include <asm-generic/atomic.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -0700202#endif /* _ASM_ATOMIC_H */