WebSVN – HelenOS – Diff – /branches/network/kernel/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 arm32
 * @{
 */
/** @file
 *  @brief Atomic operations.
 */
 
#ifndef KERN_arm32_ATOMIC_H_
#define KERN_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, [%[mem]]\n"
            "add r3, r2, %[i]\n"
            "str r3, %[ret]\n"
            "swp r3, r3, [%[mem]]\n"
            "cmp r3, r2\n"
            "bne 1b\n"
 
        : [ret] "=m" (ret)
        : [mem] "r" (mem), [i] "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 3386	Rev 4153
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 arm32	29	/** @addtogroup arm32
30	* @{	30	* @{
31	*/	31	*/
32	/** @file	32	/** @file
33	* @brief Atomic operations.	33	* @brief Atomic operations.
34	*/	34	*/
35		35
36	#ifndef KERN_arm32_ATOMIC_H_	36	#ifndef KERN_arm32_ATOMIC_H_
37	#define KERN_arm32_ATOMIC_H_	37	#define KERN_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	*/
46	static inline long atomic_add(atomic_t *val, int i)	47	static inline long atomic_add(atomic_t *val, int i)
47	{	48	{
48	int ret;	49	int ret;
49	volatile long *mem = &(val->count);	50	volatile long *mem = &(val->count);
50		51
51	asm volatile (	52	asm volatile (
52	"1:\n"	53	"1:\n"
53	"ldr r2, [%1] \n"	54	"ldr r2, [%[mem]]\n"
54	"add r3, r2, %2 \n"	55	"add r3, r2, %[i]\n"
55	"str r3, %0 \n"	56	"str r3, %[ret]\n"
56	"swp r3, r3, [%1] \n"	57	"swp r3, r3, [%[mem]]\n"
57	"cmp r3, r2 \n"	58	"cmp r3, r2\n"
58	"bne 1b \n"	59	"bne 1b\n"
59		-
60	: "=m" (ret)	60	: [ret] "=m" (ret)
61	: "r" (mem), "r" (i)	61	: [mem] "r" (mem), [i] "r" (i)
62	: "r3", "r2"	62	: "r3", "r2"
63	);	63	);
64		64
65	return ret;	65	return ret;
66	}	66	}
67		67
68	/** Atomic increment.	68	/** Atomic increment.
69	*	69	*
70	* @param val Variable to be incremented.	70	* @param val Variable to be incremented.
71	*/	71	*/
72	static inline void atomic_inc(atomic_t *val)	72	static inline void atomic_inc(atomic_t *val)
73	{	73	{
74	atomic_add(val, 1);	74	atomic_add(val, 1);
75	}	75	}
76		76
77	/** Atomic decrement.	77	/** Atomic decrement.
78	*	78	*
79	* @param val Variable to be decremented.	79	* @param val Variable to be decremented.
80	*/	80	*/
81	static inline void atomic_dec(atomic_t *val) {	81	static inline void atomic_dec(atomic_t *val) {
82	atomic_add(val, -1);	82	atomic_add(val, -1);
83	}	83	}
84		84
85	/** Atomic pre-increment.	85	/** Atomic pre-increment.
86	*	86	*
87	* @param val Variable to be incremented.	87	* @param val Variable to be incremented.
88	* @return Value after incrementation.	88	* @return Value after incrementation.
89	*/	89	*/
90	static inline long atomic_preinc(atomic_t *val)	90	static inline long atomic_preinc(atomic_t *val)
91	{	91	{
92	return atomic_add(val, 1);	92	return atomic_add(val, 1);
93	}	93	}
94		94
95	/** Atomic pre-decrement.	95	/** Atomic pre-decrement.
96	*	96	*
97	* @param val Variable to be decremented.	97	* @param val Variable to be decremented.
98	* @return Value after decrementation.	98	* @return Value after decrementation.
99	*/	99	*/
100	static inline long atomic_predec(atomic_t *val)	100	static inline long atomic_predec(atomic_t *val)
101	{	101	{
102	return atomic_add(val, -1);	102	return atomic_add(val, -1);
103	}	103	}
104		104
105	/** Atomic post-increment.	105	/** Atomic post-increment.
106	*	106	*
107	* @param val Variable to be incremented.	107	* @param val Variable to be incremented.
108	* @return Value before incrementation.	108	* @return Value before incrementation.
109	*/	109	*/
110	static inline long atomic_postinc(atomic_t *val)	110	static inline long atomic_postinc(atomic_t *val)
111	{	111	{
112	return atomic_add(val, 1) - 1;	112	return atomic_add(val, 1) - 1;
113	}	113	}
114		114
115	/** Atomic post-decrement.	115	/** Atomic post-decrement.
116	*	116	*
117	* @param val Variable to be decremented.	117	* @param val Variable to be decremented.
118	* @return Value before decrementation.	118	* @return Value before decrementation.
119	*/	119	*/
120	static inline long atomic_postdec(atomic_t *val)	120	static inline long atomic_postdec(atomic_t *val)
121	{	121	{
122	return atomic_add(val, -1) + 1;	122	return atomic_add(val, -1) + 1;
123	}	123	}
124		124
125	#endif	125	#endif
126		126
127	/** @}	127	/** @}
128	*/	128	*/
129		129

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