WebSVN – HelenOS-historic – Diff – /kernel/trunk/generic/src/synch/spinlock.c


/*
 * Copyright (C) 2001-2004 Jakub Jermar
 * 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.
 */
 
#include <synch/spinlock.h>
#include <arch/atomic.h>
#include <arch/barrier.h>
#include <arch.h>
#include <preemption.h>
#include <print.h>
#include <debug.h>
 
#ifdef CONFIG_SMP
 
/** Initialize spinlock
 *
 * Initialize spinlock.
 *
 * @param sl Pointer to spinlock_t structure.
 */
void spinlock_initialize(spinlock_t *sl)
{
    sl->val = 0;
}
 
#ifdef CONFIG_DEBUG_SPINLOCK
/** Lock spinlock
 *
 * Lock spinlock.
 * This version has limitted ability to report
 * possible occurence of deadlock.
 *
 * @param sl Pointer to spinlock_t structure.
 */
void spinlock_lock(spinlock_t *sl)
{
    int i = 0;
    __address caller = ((__u32 *) &sl)[-1];
 
    preemption_disable();
    while (test_and_set(&sl->val)) {
        if (i++ > 300000) {
            printf("cpu%d: looping on spinlock %X, caller=%X\n", CPU->id, sl, caller);
            i = 0;
        }
    }
 
    /*
     * Prevent critical section code from bleeding out this way up.
     */
    CS_ENTER_BARRIER();
 
}
 
#else
 
/** Lock spinlock
 *
 * Lock spinlock.
 *
 * @param sl Pointer to spinlock_t structure.
 */
void spinlock_lock(spinlock_t *sl)
{
    preemption_disable();
 
    /*
     * Each architecture has its own efficient/recommended
     * implementation of spinlock.
     */
    spinlock_arch(&sl->val);
 
    /*
     * Prevent critical section code from bleeding out this way up.
     */
    CS_ENTER_BARRIER();
}
#endif
 
/** Lock spinlock conditionally
 *
 * Lock spinlock conditionally.
 * If the spinlock is not available at the moment,
 * signal failure.
 *
 * @param sl Pointer to spinlock_t structure.
 *
 * @return Zero on failure, non-zero otherwise.
 */
int spinlock_trylock(spinlock_t *sl)
{
    int rc;
   
    preemption_disable();
    rc = !test_and_set(&sl->val);
 
    /*
     * Prevent critical section code from bleeding out this way up.
     */
    CS_ENTER_BARRIER();
 
    if (!rc)
        preemption_enable();
   
    return rc;
}
 
/** Unlock spinlock
 *
 * Unlock spinlock.
 *
 * @param sl Pointer to spinlock_t structure.
 */
void spinlock_unlock(spinlock_t *sl)
{
    ASSERT(sl->val != 0);
 
    /*
     * Prevent critical section code from bleeding out this way down.
     */
    CS_LEAVE_BARRIER();
   
    sl->val = 0;
    preemption_enable();
}
 
#endif
 

Rev 430	Rev 458
1	/*	1	/*
2	* Copyright (C) 2001-2004 Jakub Jermar	2	* Copyright (C) 2001-2004 Jakub Jermar
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	#include <synch/spinlock.h>	29	#include <synch/spinlock.h>
30	#include <arch/atomic.h>	30	#include <arch/atomic.h>
31	#include <arch/barrier.h>	31	#include <arch/barrier.h>
32	#include <arch.h>	32	#include <arch.h>
33	#include <preemption.h>	33	#include <preemption.h>
34	#include <print.h>	34	#include <print.h>
35	#include <debug.h>	35	#include <debug.h>
36		36
37	#ifdef __SMP__	37	#ifdef CONFIG_SMP
38		38
39	/** Initialize spinlock	39	/** Initialize spinlock
40	*	40	*
41	* Initialize spinlock.	41	* Initialize spinlock.
42	*	42	*
43	* @param sl Pointer to spinlock_t structure.	43	* @param sl Pointer to spinlock_t structure.
44	*/	44	*/
45	void spinlock_initialize(spinlock_t *sl)	45	void spinlock_initialize(spinlock_t *sl)
46	{	46	{
47	sl->val = 0;	47	sl->val = 0;
48	}	48	}
49		49
50	#ifdef DEBUG_SPINLOCK	50	#ifdef CONFIG_DEBUG_SPINLOCK
51	/** Lock spinlock	51	/** Lock spinlock
52	*	52	*
53	* Lock spinlock.	53	* Lock spinlock.
54	* This version has limitted ability to report	54	* This version has limitted ability to report
55	* possible occurence of deadlock.	55	* possible occurence of deadlock.
56	*	56	*
57	* @param sl Pointer to spinlock_t structure.	57	* @param sl Pointer to spinlock_t structure.
58	*/	58	*/
59	void spinlock_lock(spinlock_t *sl)	59	void spinlock_lock(spinlock_t *sl)
60	{	60	{
61	int i = 0;	61	int i = 0;
62	__address caller = ((__u32 *) &sl)[-1];	62	__address caller = ((__u32 *) &sl)[-1];
63		63
64	preemption_disable();	64	preemption_disable();
65	while (test_and_set(&sl->val)) {	65	while (test_and_set(&sl->val)) {
66	if (i++ > 300000) {	66	if (i++ > 300000) {
67	printf("cpu%d: looping on spinlock %X, caller=%X\n", CPU->id, sl, caller);	67	printf("cpu%d: looping on spinlock %X, caller=%X\n", CPU->id, sl, caller);
68	i = 0;	68	i = 0;
69	}	69	}
70	}	70	}
71		71
72	/*	72	/*
73	* Prevent critical section code from bleeding out this way up.	73	* Prevent critical section code from bleeding out this way up.
74	*/	74	*/
75	CS_ENTER_BARRIER();	75	CS_ENTER_BARRIER();
76		76
77	}	77	}
78		78
79	#else	79	#else
80		80
81	/** Lock spinlock	81	/** Lock spinlock
82	*	82	*
83	* Lock spinlock.	83	* Lock spinlock.
84	*	84	*
85	* @param sl Pointer to spinlock_t structure.	85	* @param sl Pointer to spinlock_t structure.
86	*/	86	*/
87	void spinlock_lock(spinlock_t *sl)	87	void spinlock_lock(spinlock_t *sl)
88	{	88	{
89	preemption_disable();	89	preemption_disable();
90		90
91	/*	91	/*
92	* Each architecture has its own efficient/recommended	92	* Each architecture has its own efficient/recommended
93	* implementation of spinlock.	93	* implementation of spinlock.
94	*/	94	*/
95	spinlock_arch(&sl->val);	95	spinlock_arch(&sl->val);
96		96
97	/*	97	/*
98	* Prevent critical section code from bleeding out this way up.	98	* Prevent critical section code from bleeding out this way up.
99	*/	99	*/
100	CS_ENTER_BARRIER();	100	CS_ENTER_BARRIER();
101	}	101	}
102	#endif	102	#endif
103		103
104	/** Lock spinlock conditionally	104	/** Lock spinlock conditionally
105	*	105	*
106	* Lock spinlock conditionally.	106	* Lock spinlock conditionally.
107	* If the spinlock is not available at the moment,	107	* If the spinlock is not available at the moment,
108	* signal failure.	108	* signal failure.
109	*	109	*
110	* @param sl Pointer to spinlock_t structure.	110	* @param sl Pointer to spinlock_t structure.
111	*	111	*
112	* @return Zero on failure, non-zero otherwise.	112	* @return Zero on failure, non-zero otherwise.
113	*/	113	*/
114	int spinlock_trylock(spinlock_t *sl)	114	int spinlock_trylock(spinlock_t *sl)
115	{	115	{
116	int rc;	116	int rc;
117		117
118	preemption_disable();	118	preemption_disable();
119	rc = !test_and_set(&sl->val);	119	rc = !test_and_set(&sl->val);
120		120
121	/*	121	/*
122	* Prevent critical section code from bleeding out this way up.	122	* Prevent critical section code from bleeding out this way up.
123	*/	123	*/
124	CS_ENTER_BARRIER();	124	CS_ENTER_BARRIER();
125		125
126	if (!rc)	126	if (!rc)
127	preemption_enable();	127	preemption_enable();
128		128
129	return rc;	129	return rc;
130	}	130	}
131		131
132	/** Unlock spinlock	132	/** Unlock spinlock
133	*	133	*
134	* Unlock spinlock.	134	* Unlock spinlock.
135	*	135	*
136	* @param sl Pointer to spinlock_t structure.	136	* @param sl Pointer to spinlock_t structure.
137	*/	137	*/
138	void spinlock_unlock(spinlock_t *sl)	138	void spinlock_unlock(spinlock_t *sl)
139	{	139	{
140	ASSERT(sl->val != 0);	140	ASSERT(sl->val != 0);
141		141
142	/*	142	/*
143	* Prevent critical section code from bleeding out this way down.	143	* Prevent critical section code from bleeding out this way down.
144	*/	144	*/
145	CS_LEAVE_BARRIER();	145	CS_LEAVE_BARRIER();
146		146
147	sl->val = 0;	147	sl->val = 0;
148	preemption_enable();	148	preemption_enable();
149	}	149	}
150		150
151	#endif	151	#endif
152		152

Subversion Repositories HelenOS-historic

(root)/kernel/trunk/generic/src/synch/spinlock.c @ 1757 – Rev 430 → 458