WebSVN – HelenOS – Diff – /branches/arm/uspace/libc/arch/arm32/include/atomic.h


/*
 * Copyright (c) 2007 Michal Kebrt
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 *
 * - Redistributions of source code must retain the above copyright
 *   notice, this list of conditions and the following disclaimer.
 * - Redistributions in binary form must reproduce the above copyright
 *   notice, this list of conditions and the following disclaimer in the
 *   documentation and/or other materials provided with the distribution.
 * - The name of the author may not be used to endorse or promote products
 *   derived from this software without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 */
 
/** @addtogroup libcarm32  
 * @{
 */
/** @file
 *  @brief Atomic operations.
 */
 
#ifndef LIBC_arm32_ATOMIC_H_
#define LIBC_arm32_ATOMIC_H_
 
/** Atomic addition.
 *
 * @param val Where to add.
 * @param i   Value to be added.
 *
 * @return Value after addition.
 */
static inline long atomic_add(atomic_t *val, int i)
{
    int ret;
    volatile long * mem = &(val->count);
 
    asm volatile (
        "1:                 \n"
        "ldr r2, [%1]       \n"
        "add r3, r2, %2     \n"
        "str r3, %0         \n"
        "swp r3, r3, [%1]   \n"
        "cmp r3, r2         \n"
        "bne 1b             \n"
 
        : "=m" (ret)
        : "r" (mem), "r" (i)
        : "r3", "r2"
    );
 
    return ret;
}
 
 
/** Atomic increment.
 *
 * @param val Variable to be incremented.
 */
static inline void atomic_inc(atomic_t *val) { atomic_add(val, 1); }
 
 
/** Atomic decrement.
 *
 * @param val Variable to be decremented.
 */
static inline void atomic_dec(atomic_t *val) { atomic_add(val, -1); }
 
 
/** Atomic pre-increment.
 *
 * @param val Variable to be incremented.
 * @return    Value after incrementation.
 */
static inline long atomic_preinc(atomic_t *val) { return atomic_add(val, 1); }
 
 
/** Atomic pre-decrement.
 *
 * @param val Variable to be decremented.
 * @return    Value after decrementation.
 */
static inline long atomic_predec(atomic_t *val) { return atomic_add(val, -1); }
 
 
/** Atomic post-increment.
 *
 * @param val Variable to be incremented.
 * @return    Value before incrementation.
 */
static inline long atomic_postinc(atomic_t *val) { return atomic_add(val, 1) - 1; }
 
 
/** Atomic post-decrement.
 *
 * @param val Variable to be decremented.
 * @return    Value before decrementation.
 */
static inline long atomic_postdec(atomic_t *val) { return atomic_add(val, -1) + 1; }
 
 
#endif
 
/** @}
 */
 

Rev 2350	Rev 2412
1	/*	1	/*
2	* Copyright (c) 2007 Michal Kebrt	2	* Copyright (c) 2007 Michal Kebrt
3	* All rights reserved.	3	* All rights reserved.
4	*	4	*
5	* Redistribution and use in source and binary forms, with or without	5	* Redistribution and use in source and binary forms, with or without
6	* modification, are permitted provided that the following conditions	6	* modification, are permitted provided that the following conditions
7	* are met:	7	* are met:
8	*	8	*
9	* - Redistributions of source code must retain the above copyright	9	* - Redistributions of source code must retain the above copyright
10	* notice, this list of conditions and the following disclaimer.	10	* notice, this list of conditions and the following disclaimer.
11	* - Redistributions in binary form must reproduce the above copyright	11	* - Redistributions in binary form must reproduce the above copyright
12	* notice, this list of conditions and the following disclaimer in the	12	* notice, this list of conditions and the following disclaimer in the
13	* documentation and/or other materials provided with the distribution.	13	* documentation and/or other materials provided with the distribution.
14	* - The name of the author may not be used to endorse or promote products	14	* - The name of the author may not be used to endorse or promote products
15	* derived from this software without specific prior written permission.	15	* derived from this software without specific prior written permission.
16	*	16	*
17	* THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR	17	* THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
18	* IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES	18	* IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
19	* OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.	19	* OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
20	* IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,	20	* IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
21	* INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT	21	* INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
22	* NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,	22	* NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
23	* DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY	23	* DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
24	* THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT	24	* THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
25	* (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF	25	* (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
26	* THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.	26	* THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
27	*/	27	*/
28		28
29	/** @addtogroup libcarm32	29	/** @addtogroup libcarm32
30	* @{	30	* @{
31	*/	31	*/
32	/** @file	32	/** @file
33	* @brief Atomic operations.	33	* @brief Atomic operations.
34	*/	34	*/
35		35
36	#ifndef LIBC_arm32_ATOMIC_H_	36	#ifndef LIBC_arm32_ATOMIC_H_
37	#define LIBC_arm32_ATOMIC_H_	37	#define LIBC_arm32_ATOMIC_H_
38		38
39	/** Atomic addition.	39	/** Atomic addition.
40	*	40	*
41	* @param val Where to add.	41	* @param val Where to add.
42	* @param i Value to be added.	42	* @param i Value to be added.
43	*	43	*
44	* @return Value after addition.	44	* @return Value after addition.
45	*/	45	*/
46	static inline long atomic_add(atomic_t *val, int i)	46	static inline long atomic_add(atomic_t *val, int i)
47	{	47	{
48	int ret;	48	int ret;
49	volatile long * mem = &(val->count);	49	volatile long * mem = &(val->count);
50		50
51	asm volatile (	51	asm volatile (
52	"1: \n"	52	"1: \n"
53	"ldr r2, [%1] \n"	53	"ldr r2, [%1] \n"
54	"add r3, r2, %2 \n"	54	"add r3, r2, %2 \n"
55	"str r3, %0 \n"	55	"str r3, %0 \n"
56	"swp r3, r3, [%1] \n"	56	"swp r3, r3, [%1] \n"
57	"cmp r3, r2 \n"	57	"cmp r3, r2 \n"
58	"bne 1b \n"	58	"bne 1b \n"
59		59
60	: "=m" (ret)	60	: "=m" (ret)
61	: "r" (mem), "r" (i)	61	: "r" (mem), "r" (i)
62	: "r3", "r2"	62	: "r3", "r2"
63	);	63	);
64		64
65	return ret;	65	return ret;
66	}	66	}
67		67
68		68
69	/** Atomic increment.	69	/** Atomic increment.
70	*	70	*
71	* @param val Variable to be incremented.	71	* @param val Variable to be incremented.
72	*/	72	*/
73	static inline void atomic_inc(atomic_t *val) { atomic_add(val, 1); }	73	static inline void atomic_inc(atomic_t *val) { atomic_add(val, 1); }
74		74
-		75
75	/** Atomic decrement.	76	/** Atomic decrement.
76	*	77	*
77	* @param val Variable to be decremented.	78	* @param val Variable to be decremented.
78	*/	79	*/
79	static inline void atomic_dec(atomic_t *val) { atomic_add(val, -1); }	80	static inline void atomic_dec(atomic_t *val) { atomic_add(val, -1); }
80		81
-		82
81	/** Atomic pre-increment.	83	/** Atomic pre-increment.
82	*	84	*
83	* @param val Variable to be incremented.	85	* @param val Variable to be incremented.
84	* @return Value after incrementation.	86	* @return Value after incrementation.
85	*/	87	*/
86	static inline long atomic_preinc(atomic_t *val) { return atomic_add(val, 1); }	88	static inline long atomic_preinc(atomic_t *val) { return atomic_add(val, 1); }
87		89
-		90
88	/** Atomic pre-decrement.	91	/** Atomic pre-decrement.
89	*	92	*
90	* @param val Variable to be decremented.	93	* @param val Variable to be decremented.
91	* @return Value after decrementation.	94	* @return Value after decrementation.
92	*/	95	*/
93	static inline long atomic_predec(atomic_t *val) { return atomic_add(val, -1); }	96	static inline long atomic_predec(atomic_t *val) { return atomic_add(val, -1); }
94		97
-		98
95	/** Atomic post-increment.	99	/** Atomic post-increment.
96	*	100	*
97	* @param val Variable to be incremented.	101	* @param val Variable to be incremented.
98	* @return Value before incrementation.	102	* @return Value before incrementation.
99	*/	103	*/
100	static inline long atomic_postinc(atomic_t *val) { return atomic_add(val, 1) - 1; }	104	static inline long atomic_postinc(atomic_t *val) { return atomic_add(val, 1) - 1; }
101		105
-		106
102	/** Atomic post-decrement.	107	/** Atomic post-decrement.
103	*	108	*
104	* @param val Variable to be decremented.	109	* @param val Variable to be decremented.
105	* @return Value before decrementation.	110	* @return Value before decrementation.
106	*/	111	*/
107	static inline long atomic_postdec(atomic_t *val) { return atomic_add(val, -1) + 1; }	112	static inline long atomic_postdec(atomic_t *val) { return atomic_add(val, -1) + 1; }
108		113
109		114
110	#endif	115	#endif
111		116
112	/** @}	117	/** @}
113	*/	118	*/
114		119

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(root)/branches/arm/uspace/libc/arch/arm32/include/atomic.h – Rev 2350 → 2412