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>
#include <symtab.h>
 
#ifdef CONFIG_SMP
 
/** Initialize spinlock
 *
 * Initialize spinlock.
 *
 * @param sl Pointer to spinlock_t structure.
 */
void spinlock_initialize(spinlock_t *sl, char *name)
{
    sl->val = 0;
#ifdef CONFIG_DEBUG_SPINLOCK
    sl->name = name;
#endif  
}
 
#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 = ((__address *) &sl)[-1];
    char *symbol;
 
    preemption_disable();
    while (test_and_set(&sl->val)) {
        if (i++ > 300000) {
            printf("cpu%d: looping on spinlock %p:%s, caller=%p",
                   CPU->id, sl, sl->name, caller);
            symbol = get_symtab_entry(caller);
            if (symbol)
                printf("(%s)", symbol);
            printf("\n");
            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 534	Rev 552
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	#include <symtab.h>
36		37
37	#ifdef CONFIG_SMP	38	#ifdef CONFIG_SMP
38		39
39	/** Initialize spinlock	40	/** Initialize spinlock
40	*	41	*
41	* Initialize spinlock.	42	* Initialize spinlock.
42	*	43	*
43	* @param sl Pointer to spinlock_t structure.	44	* @param sl Pointer to spinlock_t structure.
44	*/	45	*/
45	void spinlock_initialize(spinlock_t *sl)	46	void spinlock_initialize(spinlock_t sl, char name)
46	{	47	{
47	sl->val = 0;	48	sl->val = 0;
-		49	#ifdef CONFIG_DEBUG_SPINLOCK
-		50	sl->name = name;
-		51	#endif
48	}	52	}
49		53
50	#ifdef CONFIG_DEBUG_SPINLOCK	54	#ifdef CONFIG_DEBUG_SPINLOCK
51	/** Lock spinlock	55	/** Lock spinlock
52	*	56	*
53	* Lock spinlock.	57	* Lock spinlock.
54	* This version has limitted ability to report	58	* This version has limitted ability to report
55	* possible occurence of deadlock.	59	* possible occurence of deadlock.
56	*	60	*
57	* @param sl Pointer to spinlock_t structure.	61	* @param sl Pointer to spinlock_t structure.
58	*/	62	*/
59	void spinlock_lock(spinlock_t *sl)	63	void spinlock_lock(spinlock_t *sl)
60	{	64	{
61	int i = 0;	65	int i = 0;
62	__address caller = ((__u32 *) &sl)[-1];	66	__address caller = ((__address *) &sl)[-1];
-		67	char *symbol;
63		68
64	preemption_disable();	69	preemption_disable();
65	while (test_and_set(&sl->val)) {	70	while (test_and_set(&sl->val)) {
66	if (i++ > 300000) {	71	if (i++ > 300000) {
67	printf("cpu%d: looping on spinlock %X, caller=%X\n", CPU->id, sl, caller);	72	printf("cpu%d: looping on spinlock %p:%s, caller=%p",
-		73	CPU->id, sl, sl->name, caller);
-		74	symbol = get_symtab_entry(caller);
-		75	if (symbol)
-		76	printf("(%s)", symbol);
-		77	printf("\n");
68	i = 0;	78	i = 0;
69	}	79	}
70	}	80	}
71		81
72	/*	82	/*
73	* Prevent critical section code from bleeding out this way up.	83	* Prevent critical section code from bleeding out this way up.
74	*/	84	*/
75	CS_ENTER_BARRIER();	85	CS_ENTER_BARRIER();
76		86
77	}	87	}
78		88
79	#else	89	#else
80		90
81	/** Lock spinlock	91	/** Lock spinlock
82	*	92	*
83	* Lock spinlock.	93	* Lock spinlock.
84	*	94	*
85	* @param sl Pointer to spinlock_t structure.	95	* @param sl Pointer to spinlock_t structure.
86	*/	96	*/
87	void spinlock_lock(spinlock_t *sl)	97	void spinlock_lock(spinlock_t *sl)
88	{	98	{
89	preemption_disable();	99	preemption_disable();
90		100
91	/*	101	/*
92	* Each architecture has its own efficient/recommended	102	* Each architecture has its own efficient/recommended
93	* implementation of spinlock.	103	* implementation of spinlock.
94	*/	104	*/
95	spinlock_arch(&sl->val);	105	spinlock_arch(&sl->val);
96		106
97	/*	107	/*
98	* Prevent critical section code from bleeding out this way up.	108	* Prevent critical section code from bleeding out this way up.
99	*/	109	*/
100	CS_ENTER_BARRIER();	110	CS_ENTER_BARRIER();
101	}	111	}
102	#endif	112	#endif
103		113
104	/** Lock spinlock conditionally	114	/** Lock spinlock conditionally
105	*	115	*
106	* Lock spinlock conditionally.	116	* Lock spinlock conditionally.
107	* If the spinlock is not available at the moment,	117	* If the spinlock is not available at the moment,
108	* signal failure.	118	* signal failure.
109	*	119	*
110	* @param sl Pointer to spinlock_t structure.	120	* @param sl Pointer to spinlock_t structure.
111	*	121	*
112	* @return Zero on failure, non-zero otherwise.	122	* @return Zero on failure, non-zero otherwise.
113	*/	123	*/
114	int spinlock_trylock(spinlock_t *sl)	124	int spinlock_trylock(spinlock_t *sl)
115	{	125	{
116	int rc;	126	int rc;
117		127
118	preemption_disable();	128	preemption_disable();
119	rc = !test_and_set(&sl->val);	129	rc = !test_and_set(&sl->val);
120		130
121	/*	131	/*
122	* Prevent critical section code from bleeding out this way up.	132	* Prevent critical section code from bleeding out this way up.
123	*/	133	*/
124	CS_ENTER_BARRIER();	134	CS_ENTER_BARRIER();
125		135
126	if (!rc)	136	if (!rc)
127	preemption_enable();	137	preemption_enable();
128		138
129	return rc;	139	return rc;
130	}	140	}
131		141
132	/** Unlock spinlock	142	/** Unlock spinlock
133	*	143	*
134	* Unlock spinlock.	144	* Unlock spinlock.
135	*	145	*
136	* @param sl Pointer to spinlock_t structure.	146	* @param sl Pointer to spinlock_t structure.
137	*/	147	*/
138	void spinlock_unlock(spinlock_t *sl)	148	void spinlock_unlock(spinlock_t *sl)
139	{	149	{
140	ASSERT(sl->val != 0);	150	ASSERT(sl->val != 0);
141		151
142	/*	152	/*
143	* Prevent critical section code from bleeding out this way down.	153	* Prevent critical section code from bleeding out this way down.
144	*/	154	*/
145	CS_LEAVE_BARRIER();	155	CS_LEAVE_BARRIER();
146		156
147	sl->val = 0;	157	sl->val = 0;
148	preemption_enable();	158	preemption_enable();
149	}	159	}
150		160
151	#endif	161	#endif
152		162

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(root)/kernel/trunk/generic/src/synch/spinlock.c – Rev 534 → 552