xref: /freebsd/sys/arm/include/atomic.h (revision ca9ac06c99bfd0150b85d4d83c396ce6237c0e05)
1 /* $NetBSD: atomic.h,v 1.1 2002/10/19 12:22:34 bsh Exp $ */
2 
3 /*-
4  * Copyright (C) 2003-2004 Olivier Houchard
5  * Copyright (C) 1994-1997 Mark Brinicombe
6  * Copyright (C) 1994 Brini
7  * All rights reserved.
8  *
9  * This code is derived from software written for Brini by Mark Brinicombe
10  *
11  * Redistribution and use in source and binary forms, with or without
12  * modification, are permitted provided that the following conditions
13  * are met:
14  * 1. Redistributions of source code must retain the above copyright
15  *    notice, this list of conditions and the following disclaimer.
16  * 2. Redistributions in binary form must reproduce the above copyright
17  *    notice, this list of conditions and the following disclaimer in the
18  *    documentation and/or other materials provided with the distribution.
19  * 3. All advertising materials mentioning features or use of this software
20  *    must display the following acknowledgement:
21  *	This product includes software developed by Brini.
22  * 4. The name of Brini may not be used to endorse or promote products
23  *    derived from this software without specific prior written permission.
24  *
25  * THIS SOFTWARE IS PROVIDED BY BRINI ``AS IS'' AND ANY EXPRESS OR
26  * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
27  * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
28  * IN NO EVENT SHALL BRINI BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
29  * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
30  * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS;
31  * OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY,
32  * WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR
33  * OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF
34  * ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
35  *
36  * $FreeBSD$
37  */
38 
39 #ifndef	_MACHINE_ATOMIC_H_
40 #define	_MACHINE_ATOMIC_H_
41 
42 
43 
44 #ifndef _LOCORE
45 
46 #include <sys/types.h>
47 
48 #ifndef I32_bit
49 #define I32_bit (1 << 7)        /* IRQ disable */
50 #endif
51 #ifndef F32_bit
52 #define F32_bit (1 << 6)        /* FIQ disable */
53 #endif
54 
55 #define __with_interrupts_disabled(expr) \
56 	do {						\
57 		u_int cpsr_save, tmp;			\
58 							\
59 		__asm __volatile(			\
60 			"mrs  %0, cpsr;"		\
61 			"orr  %1, %0, %2;"		\
62 			"msr  cpsr_all, %1;"		\
63 			: "=r" (cpsr_save), "=r" (tmp)	\
64 			: "I" (I32_bit)		\
65 		        : "cc" );		\
66 		(expr);				\
67 		 __asm __volatile(		\
68 			"msr  cpsr_all, %0"	\
69 			: /* no output */	\
70 			: "r" (cpsr_save)	\
71 			: "cc" );		\
72 	} while(0)
73 
74 static __inline uint32_t
75 __swp(uint32_t val, volatile uint32_t *ptr)
76 {
77 	__asm __volatile("swp	%0, %1, [%2]"
78 	    : "=&r" (val) : "r" (val) , "r" (ptr) : "memory");
79 	return (val);
80 }
81 
82 
83 #define atomic_op(v, op, p) ({			\
84     uint32_t e, r, s;				\
85     for (e = *(volatile uint32_t *)p;; e = r) {	\
86     	s = e op v;				\
87     	r = __swp(s, p);			\
88     	if (r == e)				\
89     		break;				\
90     }						\
91     e;						\
92 })
93 static __inline void
94 atomic_set_32(volatile uint32_t *address, uint32_t setmask)
95 {
96 	atomic_op(setmask, |, address);
97 }
98 
99 static __inline void
100 atomic_clear_32(volatile uint32_t *address, uint32_t clearmask)
101 {
102 	atomic_op(clearmask, &~, address);
103 }
104 
105 static __inline int
106 atomic_load_32(volatile uint32_t *v)
107 {
108 
109 	return (atomic_op(0, +, v));
110 }
111 
112 static __inline void
113 atomic_store_32(volatile uint32_t *dst, uint32_t src)
114 {
115 	__swp(src, dst);
116 }
117 
118 static __inline uint32_t
119 atomic_readandclear_32(volatile u_int32_t *p)
120 {
121 
122 	return (__swp(0, p));
123 }
124 
125 #ifdef _KERNEL
126 static __inline u_int32_t
127 atomic_cmpset_32(volatile u_int32_t *p, u_int32_t cmpval, u_int32_t newval)
128 {
129 	int done;
130 
131 	__with_interrupts_disabled(
132 	{
133 	    	if (*p == cmpval) {
134 			*p = newval;
135 			done = 1;
136 		} else
137 			done = 0;
138 	});
139 	return (done);
140 }
141 #endif
142 
143 static __inline void
144 atomic_add_32(volatile u_int32_t *p, u_int32_t val)
145 {
146 	atomic_op(val, +, p);
147 }
148 
149 static __inline void
150 atomic_subtract_32(volatile u_int32_t *p, u_int32_t val)
151 {
152 	atomic_op(val, -, p);
153 }
154 
155 #undef __with_interrupts_disabled
156 
157 #endif /* _LOCORE */
158 
159 
160 #define atomic_set_rel_int		atomic_set_32
161 #define atomic_set_int			atomic_set_32
162 #define atomic_readandclear_int		atomic_readandclear_32
163 #define atomic_clear_int		atomic_clear_32
164 #define atomic_subtract_int		atomic_subtract_32
165 #define atomic_subtract_rel_int		atomic_subtract_32
166 #define atomic_subtract_acq_int		atomic_subtract_32
167 #define atomic_add_int			atomic_add_32
168 #define atomic_add_rel_int		atomic_add_32
169 #define atomic_add_acq_int		atomic_add_32
170 #define atomic_cmpset_int		atomic_cmpset_32
171 #define atomic_cmpset_rel_int		atomic_cmpset_32
172 #define atomic_cmpset_rel_ptr		atomic_cmpset_ptr
173 #define atomic_cmpset_acq_int		atomic_cmpset_32
174 #define atomic_cmpset_acq_ptr		atomic_cmpset_ptr
175 #define atomic_store_rel_ptr		atomic_store_ptr
176 #define atomic_store_rel_int		atomic_store_32
177 #define atomic_cmpset_rel_32		atomic_cmpset_32
178 #define atomic_smpset_rel_ptr		atomic_cmpset_ptr
179 #define atomic_load_acq_int		atomic_load_32
180 #define atomic_clear_ptr(ptr, bit)	atomic_clear_32( \
181     (volatile uint32_t *)ptr, (uint32_t)bit)
182 #define atomic_store_ptr(ptr, bit)	atomic_store_32( \
183     (volatile uint32_t *)ptr, (uint32_t)bit)
184 #define atomic_cmpset_ptr(dst, exp, s)	atomic_cmpset_32( \
185     (volatile uint32_t *)dst, (uint32_t)exp, (uint32_t)s)
186 #define atomic_set_ptr(ptr, src)	atomic_set_32( \
187     (volatile uint32_t *)ptr,  (uint32_t)src)
188 
189 #endif /* _MACHINE_ATOMIC_H_ */
190