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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 | /** |
|
- | 30 | * @file spinlock.c |
|
- | 31 | * @brief Spinlocks. |
|
- | 32 | */ |
|
- | 33 | ||
29 | #include <synch/spinlock.h> |
34 | #include <synch/spinlock.h> |
30 | #include <atomic.h> |
35 | #include <atomic.h> |
31 | #include <arch/barrier.h> |
36 | #include <arch/barrier.h> |
32 | #include <arch.h> |
37 | #include <arch.h> |
33 | #include <preemption.h> |
38 | #include <preemption.h> |
34 | #include <print.h> |
39 | #include <print.h> |
35 | #include <debug.h> |
40 | #include <debug.h> |
36 | #include <symtab.h> |
41 | #include <symtab.h> |
37 | 42 | ||
38 | #ifdef CONFIG_SMP |
43 | #ifdef CONFIG_SMP |
39 | 44 | ||
40 | /** Initialize spinlock |
45 | /** Initialize spinlock |
41 | * |
46 | * |
42 | * Initialize spinlock. |
47 | * Initialize spinlock. |
43 | * |
48 | * |
44 | * @param sl Pointer to spinlock_t structure. |
49 | * @param sl Pointer to spinlock_t structure. |
45 | */ |
50 | */ |
46 | void spinlock_initialize(spinlock_t *sl, char *name) |
51 | void spinlock_initialize(spinlock_t *sl, char *name) |
47 | { |
52 | { |
48 | atomic_set(&sl->val, 0); |
53 | atomic_set(&sl->val, 0); |
49 | #ifdef CONFIG_DEBUG_SPINLOCK |
54 | #ifdef CONFIG_DEBUG_SPINLOCK |
50 | sl->name = name; |
55 | sl->name = name; |
51 | #endif |
56 | #endif |
52 | } |
57 | } |
53 | 58 | ||
54 | /** Lock spinlock |
59 | /** Lock spinlock |
55 | * |
60 | * |
56 | * Lock spinlock. |
61 | * Lock spinlock. |
57 | * This version has limitted ability to report |
62 | * This version has limitted ability to report |
58 | * possible occurence of deadlock. |
63 | * possible occurence of deadlock. |
59 | * |
64 | * |
60 | * @param sl Pointer to spinlock_t structure. |
65 | * @param sl Pointer to spinlock_t structure. |
61 | */ |
66 | */ |
62 | #ifdef CONFIG_DEBUG_SPINLOCK |
67 | #ifdef CONFIG_DEBUG_SPINLOCK |
63 | void spinlock_lock_debug(spinlock_t *sl) |
68 | void spinlock_lock_debug(spinlock_t *sl) |
64 | { |
69 | { |
65 | count_t i = 0; |
70 | count_t i = 0; |
66 | char *symbol; |
71 | char *symbol; |
67 | bool deadlock_reported = false; |
72 | bool deadlock_reported = false; |
68 | 73 | ||
69 | preemption_disable(); |
74 | preemption_disable(); |
70 | while (test_and_set(&sl->val)) { |
75 | while (test_and_set(&sl->val)) { |
71 | if (i++ > 300000 && sl!=&printflock) { |
76 | if (i++ > 300000 && sl!=&printflock) { |
72 | printf("cpu%d: looping on spinlock %.*p:%s, caller=%.*p", |
77 | printf("cpu%d: looping on spinlock %.*p:%s, caller=%.*p", |
73 | CPU->id, sizeof(__address) * 2, sl, sl->name, sizeof(__address) * 2, CALLER); |
78 | CPU->id, sizeof(__address) * 2, sl, sl->name, sizeof(__address) * 2, CALLER); |
74 | symbol = get_symtab_entry(CALLER); |
79 | symbol = get_symtab_entry(CALLER); |
75 | if (symbol) |
80 | if (symbol) |
76 | printf("(%s)", symbol); |
81 | printf("(%s)", symbol); |
77 | printf("\n"); |
82 | printf("\n"); |
78 | i = 0; |
83 | i = 0; |
79 | deadlock_reported = true; |
84 | deadlock_reported = true; |
80 | } |
85 | } |
81 | } |
86 | } |
82 | 87 | ||
83 | if (deadlock_reported) |
88 | if (deadlock_reported) |
84 | printf("cpu%d: not deadlocked\n", CPU->id); |
89 | printf("cpu%d: not deadlocked\n", CPU->id); |
85 | 90 | ||
86 | /* |
91 | /* |
87 | * Prevent critical section code from bleeding out this way up. |
92 | * Prevent critical section code from bleeding out this way up. |
88 | */ |
93 | */ |
89 | CS_ENTER_BARRIER(); |
94 | CS_ENTER_BARRIER(); |
90 | } |
95 | } |
91 | #endif |
96 | #endif |
92 | 97 | ||
93 | /** Lock spinlock conditionally |
98 | /** Lock spinlock conditionally |
94 | * |
99 | * |
95 | * Lock spinlock conditionally. |
100 | * Lock spinlock conditionally. |
96 | * If the spinlock is not available at the moment, |
101 | * If the spinlock is not available at the moment, |
97 | * signal failure. |
102 | * signal failure. |
98 | * |
103 | * |
99 | * @param sl Pointer to spinlock_t structure. |
104 | * @param sl Pointer to spinlock_t structure. |
100 | * |
105 | * |
101 | * @return Zero on failure, non-zero otherwise. |
106 | * @return Zero on failure, non-zero otherwise. |
102 | */ |
107 | */ |
103 | int spinlock_trylock(spinlock_t *sl) |
108 | int spinlock_trylock(spinlock_t *sl) |
104 | { |
109 | { |
105 | int rc; |
110 | int rc; |
106 | 111 | ||
107 | preemption_disable(); |
112 | preemption_disable(); |
108 | rc = !test_and_set(&sl->val); |
113 | rc = !test_and_set(&sl->val); |
109 | 114 | ||
110 | /* |
115 | /* |
111 | * Prevent critical section code from bleeding out this way up. |
116 | * Prevent critical section code from bleeding out this way up. |
112 | */ |
117 | */ |
113 | CS_ENTER_BARRIER(); |
118 | CS_ENTER_BARRIER(); |
114 | 119 | ||
115 | if (!rc) |
120 | if (!rc) |
116 | preemption_enable(); |
121 | preemption_enable(); |
117 | 122 | ||
118 | return rc; |
123 | return rc; |
119 | } |
124 | } |
120 | 125 | ||
121 | #endif |
126 | #endif |
122 | 127 |