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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 | ||
fb1c8f93 IM |
9 | #include <linux/spinlock.h> |
10 | #include <linux/interrupt.h> | |
11 | #include <linux/delay.h> | |
12 | ||
13 | static void spin_bug(spinlock_t *lock, const char *msg) | |
14 | { | |
15 | static long print_once = 1; | |
16 | struct task_struct *owner = NULL; | |
17 | ||
18 | if (xchg(&print_once, 0)) { | |
19 | if (lock->owner && lock->owner != SPINLOCK_OWNER_INIT) | |
20 | owner = lock->owner; | |
51989b9f | 21 | printk(KERN_EMERG "BUG: spinlock %s on CPU#%d, %s/%d\n", |
bb44f116 IM |
22 | msg, raw_smp_processor_id(), |
23 | current->comm, current->pid); | |
51989b9f DJ |
24 | printk(KERN_EMERG " lock: %p, .magic: %08x, .owner: %s/%d, " |
25 | ".owner_cpu: %d\n", | |
fb1c8f93 IM |
26 | lock, lock->magic, |
27 | owner ? owner->comm : "<none>", | |
28 | owner ? owner->pid : -1, | |
29 | lock->owner_cpu); | |
30 | dump_stack(); | |
31 | #ifdef CONFIG_SMP | |
32 | /* | |
33 | * We cannot continue on SMP: | |
34 | */ | |
35 | // panic("bad locking"); | |
36 | #endif | |
37 | } | |
38 | } | |
39 | ||
40 | #define SPIN_BUG_ON(cond, lock, msg) if (unlikely(cond)) spin_bug(lock, msg) | |
41 | ||
42 | static inline void debug_spin_lock_before(spinlock_t *lock) | |
43 | { | |
44 | SPIN_BUG_ON(lock->magic != SPINLOCK_MAGIC, lock, "bad magic"); | |
45 | SPIN_BUG_ON(lock->owner == current, lock, "recursion"); | |
46 | SPIN_BUG_ON(lock->owner_cpu == raw_smp_processor_id(), | |
47 | lock, "cpu recursion"); | |
48 | } | |
49 | ||
50 | static inline void debug_spin_lock_after(spinlock_t *lock) | |
51 | { | |
52 | lock->owner_cpu = raw_smp_processor_id(); | |
53 | lock->owner = current; | |
54 | } | |
55 | ||
56 | static inline void debug_spin_unlock(spinlock_t *lock) | |
57 | { | |
58 | SPIN_BUG_ON(lock->magic != SPINLOCK_MAGIC, lock, "bad magic"); | |
59 | SPIN_BUG_ON(!spin_is_locked(lock), lock, "already unlocked"); | |
60 | SPIN_BUG_ON(lock->owner != current, lock, "wrong owner"); | |
61 | SPIN_BUG_ON(lock->owner_cpu != raw_smp_processor_id(), | |
62 | lock, "wrong CPU"); | |
63 | lock->owner = SPINLOCK_OWNER_INIT; | |
64 | lock->owner_cpu = -1; | |
65 | } | |
66 | ||
67 | static void __spin_lock_debug(spinlock_t *lock) | |
68 | { | |
69 | int print_once = 1; | |
70 | u64 i; | |
71 | ||
72 | for (;;) { | |
73 | for (i = 0; i < loops_per_jiffy * HZ; i++) { | |
fb1c8f93 IM |
74 | if (__raw_spin_trylock(&lock->raw_lock)) |
75 | return; | |
e0a60296 | 76 | __delay(1); |
fb1c8f93 IM |
77 | } |
78 | /* lockup suspected: */ | |
79 | if (print_once) { | |
80 | print_once = 0; | |
51989b9f DJ |
81 | printk(KERN_EMERG "BUG: spinlock lockup on CPU#%d, " |
82 | "%s/%d, %p\n", | |
bb44f116 IM |
83 | raw_smp_processor_id(), current->comm, |
84 | current->pid, lock); | |
fb1c8f93 IM |
85 | dump_stack(); |
86 | } | |
87 | } | |
88 | } | |
89 | ||
90 | void _raw_spin_lock(spinlock_t *lock) | |
91 | { | |
92 | debug_spin_lock_before(lock); | |
93 | if (unlikely(!__raw_spin_trylock(&lock->raw_lock))) | |
94 | __spin_lock_debug(lock); | |
95 | debug_spin_lock_after(lock); | |
96 | } | |
97 | ||
98 | int _raw_spin_trylock(spinlock_t *lock) | |
99 | { | |
100 | int ret = __raw_spin_trylock(&lock->raw_lock); | |
101 | ||
102 | if (ret) | |
103 | debug_spin_lock_after(lock); | |
104 | #ifndef CONFIG_SMP | |
105 | /* | |
106 | * Must not happen on UP: | |
107 | */ | |
108 | SPIN_BUG_ON(!ret, lock, "trylock failure on UP"); | |
109 | #endif | |
110 | return ret; | |
111 | } | |
112 | ||
113 | void _raw_spin_unlock(spinlock_t *lock) | |
114 | { | |
115 | debug_spin_unlock(lock); | |
116 | __raw_spin_unlock(&lock->raw_lock); | |
117 | } | |
118 | ||
119 | static void rwlock_bug(rwlock_t *lock, const char *msg) | |
120 | { | |
121 | static long print_once = 1; | |
122 | ||
123 | if (xchg(&print_once, 0)) { | |
51989b9f DJ |
124 | printk(KERN_EMERG "BUG: rwlock %s on CPU#%d, %s/%d, %p\n", |
125 | msg, raw_smp_processor_id(), current->comm, | |
bb44f116 | 126 | current->pid, lock); |
fb1c8f93 IM |
127 | dump_stack(); |
128 | #ifdef CONFIG_SMP | |
129 | /* | |
130 | * We cannot continue on SMP: | |
131 | */ | |
132 | panic("bad locking"); | |
133 | #endif | |
134 | } | |
135 | } | |
136 | ||
137 | #define RWLOCK_BUG_ON(cond, lock, msg) if (unlikely(cond)) rwlock_bug(lock, msg) | |
138 | ||
139 | static void __read_lock_debug(rwlock_t *lock) | |
140 | { | |
141 | int print_once = 1; | |
142 | u64 i; | |
143 | ||
144 | for (;;) { | |
145 | for (i = 0; i < loops_per_jiffy * HZ; i++) { | |
fb1c8f93 IM |
146 | if (__raw_read_trylock(&lock->raw_lock)) |
147 | return; | |
e0a60296 | 148 | __delay(1); |
fb1c8f93 IM |
149 | } |
150 | /* lockup suspected: */ | |
151 | if (print_once) { | |
152 | print_once = 0; | |
51989b9f DJ |
153 | printk(KERN_EMERG "BUG: read-lock lockup on CPU#%d, " |
154 | "%s/%d, %p\n", | |
bb44f116 IM |
155 | raw_smp_processor_id(), current->comm, |
156 | current->pid, lock); | |
fb1c8f93 IM |
157 | dump_stack(); |
158 | } | |
159 | } | |
160 | } | |
161 | ||
162 | void _raw_read_lock(rwlock_t *lock) | |
163 | { | |
164 | RWLOCK_BUG_ON(lock->magic != RWLOCK_MAGIC, lock, "bad magic"); | |
165 | if (unlikely(!__raw_read_trylock(&lock->raw_lock))) | |
166 | __read_lock_debug(lock); | |
167 | } | |
168 | ||
169 | int _raw_read_trylock(rwlock_t *lock) | |
170 | { | |
171 | int ret = __raw_read_trylock(&lock->raw_lock); | |
172 | ||
173 | #ifndef CONFIG_SMP | |
174 | /* | |
175 | * Must not happen on UP: | |
176 | */ | |
177 | RWLOCK_BUG_ON(!ret, lock, "trylock failure on UP"); | |
178 | #endif | |
179 | return ret; | |
180 | } | |
181 | ||
182 | void _raw_read_unlock(rwlock_t *lock) | |
183 | { | |
184 | RWLOCK_BUG_ON(lock->magic != RWLOCK_MAGIC, lock, "bad magic"); | |
185 | __raw_read_unlock(&lock->raw_lock); | |
186 | } | |
187 | ||
188 | static inline void debug_write_lock_before(rwlock_t *lock) | |
189 | { | |
190 | RWLOCK_BUG_ON(lock->magic != RWLOCK_MAGIC, lock, "bad magic"); | |
191 | RWLOCK_BUG_ON(lock->owner == current, lock, "recursion"); | |
192 | RWLOCK_BUG_ON(lock->owner_cpu == raw_smp_processor_id(), | |
193 | lock, "cpu recursion"); | |
194 | } | |
195 | ||
196 | static inline void debug_write_lock_after(rwlock_t *lock) | |
197 | { | |
198 | lock->owner_cpu = raw_smp_processor_id(); | |
199 | lock->owner = current; | |
200 | } | |
201 | ||
202 | static inline void debug_write_unlock(rwlock_t *lock) | |
203 | { | |
204 | RWLOCK_BUG_ON(lock->magic != RWLOCK_MAGIC, lock, "bad magic"); | |
205 | RWLOCK_BUG_ON(lock->owner != current, lock, "wrong owner"); | |
206 | RWLOCK_BUG_ON(lock->owner_cpu != raw_smp_processor_id(), | |
207 | lock, "wrong CPU"); | |
208 | lock->owner = SPINLOCK_OWNER_INIT; | |
209 | lock->owner_cpu = -1; | |
210 | } | |
211 | ||
212 | static void __write_lock_debug(rwlock_t *lock) | |
213 | { | |
214 | int print_once = 1; | |
215 | u64 i; | |
216 | ||
217 | for (;;) { | |
218 | for (i = 0; i < loops_per_jiffy * HZ; i++) { | |
fb1c8f93 IM |
219 | if (__raw_write_trylock(&lock->raw_lock)) |
220 | return; | |
e0a60296 | 221 | __delay(1); |
fb1c8f93 IM |
222 | } |
223 | /* lockup suspected: */ | |
224 | if (print_once) { | |
225 | print_once = 0; | |
51989b9f DJ |
226 | printk(KERN_EMERG "BUG: write-lock lockup on CPU#%d, " |
227 | "%s/%d, %p\n", | |
bb44f116 IM |
228 | raw_smp_processor_id(), current->comm, |
229 | current->pid, lock); | |
fb1c8f93 IM |
230 | dump_stack(); |
231 | } | |
232 | } | |
233 | } | |
234 | ||
235 | void _raw_write_lock(rwlock_t *lock) | |
236 | { | |
237 | debug_write_lock_before(lock); | |
238 | if (unlikely(!__raw_write_trylock(&lock->raw_lock))) | |
239 | __write_lock_debug(lock); | |
240 | debug_write_lock_after(lock); | |
241 | } | |
242 | ||
243 | int _raw_write_trylock(rwlock_t *lock) | |
244 | { | |
245 | int ret = __raw_write_trylock(&lock->raw_lock); | |
246 | ||
247 | if (ret) | |
248 | debug_write_lock_after(lock); | |
249 | #ifndef CONFIG_SMP | |
250 | /* | |
251 | * Must not happen on UP: | |
252 | */ | |
253 | RWLOCK_BUG_ON(!ret, lock, "trylock failure on UP"); | |
254 | #endif | |
255 | return ret; | |
256 | } | |
257 | ||
258 | void _raw_write_unlock(rwlock_t *lock) | |
259 | { | |
260 | debug_write_unlock(lock); | |
261 | __raw_write_unlock(&lock->raw_lock); | |
262 | } |