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fb1c8f93 IM |
1 | /* |
2 | * Copyright 2005, Red Hat, Inc., Ingo Molnar | |
3 | * Released under the General Public License (GPL). | |
4 | * | |
5 | * This file contains the spinlock/rwlock implementations for | |
6 | * DEBUG_SPINLOCK. | |
7 | */ | |
8 | ||
9 | #include <linux/config.h> | |
10 | #include <linux/spinlock.h> | |
11 | #include <linux/interrupt.h> | |
12 | #include <linux/delay.h> | |
13 | ||
14 | static void spin_bug(spinlock_t *lock, const char *msg) | |
15 | { | |
16 | static long print_once = 1; | |
17 | struct task_struct *owner = NULL; | |
18 | ||
19 | if (xchg(&print_once, 0)) { | |
20 | if (lock->owner && lock->owner != SPINLOCK_OWNER_INIT) | |
21 | owner = lock->owner; | |
51989b9f | 22 | printk(KERN_EMERG "BUG: spinlock %s on CPU#%d, %s/%d\n", |
bb44f116 IM |
23 | msg, raw_smp_processor_id(), |
24 | current->comm, current->pid); | |
51989b9f DJ |
25 | printk(KERN_EMERG " lock: %p, .magic: %08x, .owner: %s/%d, " |
26 | ".owner_cpu: %d\n", | |
fb1c8f93 IM |
27 | lock, lock->magic, |
28 | owner ? owner->comm : "<none>", | |
29 | owner ? owner->pid : -1, | |
30 | lock->owner_cpu); | |
31 | dump_stack(); | |
32 | #ifdef CONFIG_SMP | |
33 | /* | |
34 | * We cannot continue on SMP: | |
35 | */ | |
36 | // panic("bad locking"); | |
37 | #endif | |
38 | } | |
39 | } | |
40 | ||
41 | #define SPIN_BUG_ON(cond, lock, msg) if (unlikely(cond)) spin_bug(lock, msg) | |
42 | ||
43 | static inline void debug_spin_lock_before(spinlock_t *lock) | |
44 | { | |
45 | SPIN_BUG_ON(lock->magic != SPINLOCK_MAGIC, lock, "bad magic"); | |
46 | SPIN_BUG_ON(lock->owner == current, lock, "recursion"); | |
47 | SPIN_BUG_ON(lock->owner_cpu == raw_smp_processor_id(), | |
48 | lock, "cpu recursion"); | |
49 | } | |
50 | ||
51 | static inline void debug_spin_lock_after(spinlock_t *lock) | |
52 | { | |
53 | lock->owner_cpu = raw_smp_processor_id(); | |
54 | lock->owner = current; | |
55 | } | |
56 | ||
57 | static inline void debug_spin_unlock(spinlock_t *lock) | |
58 | { | |
59 | SPIN_BUG_ON(lock->magic != SPINLOCK_MAGIC, lock, "bad magic"); | |
60 | SPIN_BUG_ON(!spin_is_locked(lock), lock, "already unlocked"); | |
61 | SPIN_BUG_ON(lock->owner != current, lock, "wrong owner"); | |
62 | SPIN_BUG_ON(lock->owner_cpu != raw_smp_processor_id(), | |
63 | lock, "wrong CPU"); | |
64 | lock->owner = SPINLOCK_OWNER_INIT; | |
65 | lock->owner_cpu = -1; | |
66 | } | |
67 | ||
68 | static void __spin_lock_debug(spinlock_t *lock) | |
69 | { | |
70 | int print_once = 1; | |
71 | u64 i; | |
72 | ||
73 | for (;;) { | |
74 | for (i = 0; i < loops_per_jiffy * HZ; i++) { | |
75 | cpu_relax(); | |
76 | if (__raw_spin_trylock(&lock->raw_lock)) | |
77 | return; | |
78 | } | |
79 | /* lockup suspected: */ | |
80 | if (print_once) { | |
81 | print_once = 0; | |
51989b9f DJ |
82 | printk(KERN_EMERG "BUG: spinlock lockup on CPU#%d, " |
83 | "%s/%d, %p\n", | |
bb44f116 IM |
84 | raw_smp_processor_id(), current->comm, |
85 | current->pid, lock); | |
fb1c8f93 IM |
86 | dump_stack(); |
87 | } | |
88 | } | |
89 | } | |
90 | ||
91 | void _raw_spin_lock(spinlock_t *lock) | |
92 | { | |
93 | debug_spin_lock_before(lock); | |
94 | if (unlikely(!__raw_spin_trylock(&lock->raw_lock))) | |
95 | __spin_lock_debug(lock); | |
96 | debug_spin_lock_after(lock); | |
97 | } | |
98 | ||
99 | int _raw_spin_trylock(spinlock_t *lock) | |
100 | { | |
101 | int ret = __raw_spin_trylock(&lock->raw_lock); | |
102 | ||
103 | if (ret) | |
104 | debug_spin_lock_after(lock); | |
105 | #ifndef CONFIG_SMP | |
106 | /* | |
107 | * Must not happen on UP: | |
108 | */ | |
109 | SPIN_BUG_ON(!ret, lock, "trylock failure on UP"); | |
110 | #endif | |
111 | return ret; | |
112 | } | |
113 | ||
114 | void _raw_spin_unlock(spinlock_t *lock) | |
115 | { | |
116 | debug_spin_unlock(lock); | |
117 | __raw_spin_unlock(&lock->raw_lock); | |
118 | } | |
119 | ||
120 | static void rwlock_bug(rwlock_t *lock, const char *msg) | |
121 | { | |
122 | static long print_once = 1; | |
123 | ||
124 | if (xchg(&print_once, 0)) { | |
51989b9f DJ |
125 | printk(KERN_EMERG "BUG: rwlock %s on CPU#%d, %s/%d, %p\n", |
126 | msg, raw_smp_processor_id(), current->comm, | |
bb44f116 | 127 | current->pid, lock); |
fb1c8f93 IM |
128 | dump_stack(); |
129 | #ifdef CONFIG_SMP | |
130 | /* | |
131 | * We cannot continue on SMP: | |
132 | */ | |
133 | panic("bad locking"); | |
134 | #endif | |
135 | } | |
136 | } | |
137 | ||
138 | #define RWLOCK_BUG_ON(cond, lock, msg) if (unlikely(cond)) rwlock_bug(lock, msg) | |
139 | ||
140 | static void __read_lock_debug(rwlock_t *lock) | |
141 | { | |
142 | int print_once = 1; | |
143 | u64 i; | |
144 | ||
145 | for (;;) { | |
146 | for (i = 0; i < loops_per_jiffy * HZ; i++) { | |
147 | cpu_relax(); | |
148 | if (__raw_read_trylock(&lock->raw_lock)) | |
149 | return; | |
150 | } | |
151 | /* lockup suspected: */ | |
152 | if (print_once) { | |
153 | print_once = 0; | |
51989b9f DJ |
154 | printk(KERN_EMERG "BUG: read-lock lockup on CPU#%d, " |
155 | "%s/%d, %p\n", | |
bb44f116 IM |
156 | raw_smp_processor_id(), current->comm, |
157 | current->pid, lock); | |
fb1c8f93 IM |
158 | dump_stack(); |
159 | } | |
160 | } | |
161 | } | |
162 | ||
163 | void _raw_read_lock(rwlock_t *lock) | |
164 | { | |
165 | RWLOCK_BUG_ON(lock->magic != RWLOCK_MAGIC, lock, "bad magic"); | |
166 | if (unlikely(!__raw_read_trylock(&lock->raw_lock))) | |
167 | __read_lock_debug(lock); | |
168 | } | |
169 | ||
170 | int _raw_read_trylock(rwlock_t *lock) | |
171 | { | |
172 | int ret = __raw_read_trylock(&lock->raw_lock); | |
173 | ||
174 | #ifndef CONFIG_SMP | |
175 | /* | |
176 | * Must not happen on UP: | |
177 | */ | |
178 | RWLOCK_BUG_ON(!ret, lock, "trylock failure on UP"); | |
179 | #endif | |
180 | return ret; | |
181 | } | |
182 | ||
183 | void _raw_read_unlock(rwlock_t *lock) | |
184 | { | |
185 | RWLOCK_BUG_ON(lock->magic != RWLOCK_MAGIC, lock, "bad magic"); | |
186 | __raw_read_unlock(&lock->raw_lock); | |
187 | } | |
188 | ||
189 | static inline void debug_write_lock_before(rwlock_t *lock) | |
190 | { | |
191 | RWLOCK_BUG_ON(lock->magic != RWLOCK_MAGIC, lock, "bad magic"); | |
192 | RWLOCK_BUG_ON(lock->owner == current, lock, "recursion"); | |
193 | RWLOCK_BUG_ON(lock->owner_cpu == raw_smp_processor_id(), | |
194 | lock, "cpu recursion"); | |
195 | } | |
196 | ||
197 | static inline void debug_write_lock_after(rwlock_t *lock) | |
198 | { | |
199 | lock->owner_cpu = raw_smp_processor_id(); | |
200 | lock->owner = current; | |
201 | } | |
202 | ||
203 | static inline void debug_write_unlock(rwlock_t *lock) | |
204 | { | |
205 | RWLOCK_BUG_ON(lock->magic != RWLOCK_MAGIC, lock, "bad magic"); | |
206 | RWLOCK_BUG_ON(lock->owner != current, lock, "wrong owner"); | |
207 | RWLOCK_BUG_ON(lock->owner_cpu != raw_smp_processor_id(), | |
208 | lock, "wrong CPU"); | |
209 | lock->owner = SPINLOCK_OWNER_INIT; | |
210 | lock->owner_cpu = -1; | |
211 | } | |
212 | ||
213 | static void __write_lock_debug(rwlock_t *lock) | |
214 | { | |
215 | int print_once = 1; | |
216 | u64 i; | |
217 | ||
218 | for (;;) { | |
219 | for (i = 0; i < loops_per_jiffy * HZ; i++) { | |
220 | cpu_relax(); | |
221 | if (__raw_write_trylock(&lock->raw_lock)) | |
222 | return; | |
223 | } | |
224 | /* lockup suspected: */ | |
225 | if (print_once) { | |
226 | print_once = 0; | |
51989b9f DJ |
227 | printk(KERN_EMERG "BUG: write-lock lockup on CPU#%d, " |
228 | "%s/%d, %p\n", | |
bb44f116 IM |
229 | raw_smp_processor_id(), current->comm, |
230 | current->pid, lock); | |
fb1c8f93 IM |
231 | dump_stack(); |
232 | } | |
233 | } | |
234 | } | |
235 | ||
236 | void _raw_write_lock(rwlock_t *lock) | |
237 | { | |
238 | debug_write_lock_before(lock); | |
239 | if (unlikely(!__raw_write_trylock(&lock->raw_lock))) | |
240 | __write_lock_debug(lock); | |
241 | debug_write_lock_after(lock); | |
242 | } | |
243 | ||
244 | int _raw_write_trylock(rwlock_t *lock) | |
245 | { | |
246 | int ret = __raw_write_trylock(&lock->raw_lock); | |
247 | ||
248 | if (ret) | |
249 | debug_write_lock_after(lock); | |
250 | #ifndef CONFIG_SMP | |
251 | /* | |
252 | * Must not happen on UP: | |
253 | */ | |
254 | RWLOCK_BUG_ON(!ret, lock, "trylock failure on UP"); | |
255 | #endif | |
256 | return ret; | |
257 | } | |
258 | ||
259 | void _raw_write_unlock(rwlock_t *lock) | |
260 | { | |
261 | debug_write_unlock(lock); | |
262 | __raw_write_unlock(&lock->raw_lock); | |
263 | } |