Commit | Line | Data |
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1da177e4 LT |
1 | /* |
2 | * linux/kernel/irq/spurious.c | |
3 | * | |
4 | * Copyright (C) 1992, 1998-2004 Linus Torvalds, Ingo Molnar | |
5 | * | |
6 | * This file contains spurious interrupt handling. | |
7 | */ | |
8 | ||
188fd89d | 9 | #include <linux/jiffies.h> |
1da177e4 LT |
10 | #include <linux/irq.h> |
11 | #include <linux/module.h> | |
12 | #include <linux/kallsyms.h> | |
13 | #include <linux/interrupt.h> | |
9e094c17 | 14 | #include <linux/moduleparam.h> |
f84dbb91 | 15 | #include <linux/timer.h> |
1da177e4 | 16 | |
bd151412 TG |
17 | #include "internals.h" |
18 | ||
83d4e6e7 | 19 | static int irqfixup __read_mostly; |
200803df | 20 | |
f84dbb91 EB |
21 | #define POLL_SPURIOUS_IRQ_INTERVAL (HZ/10) |
22 | static void poll_spurious_irqs(unsigned long dummy); | |
23 | static DEFINE_TIMER(poll_spurious_irq_timer, poll_spurious_irqs, 0, 0); | |
d05c65ff TG |
24 | static int irq_poll_cpu; |
25 | static atomic_t irq_poll_active; | |
f84dbb91 | 26 | |
fe200ae4 TG |
27 | /* |
28 | * We wait here for a poller to finish. | |
29 | * | |
30 | * If the poll runs on this CPU, then we yell loudly and return | |
31 | * false. That will leave the interrupt line disabled in the worst | |
32 | * case, but it should never happen. | |
33 | * | |
34 | * We wait until the poller is done and then recheck disabled and | |
35 | * action (about to be disabled). Only if it's still active, we return | |
36 | * true and let the handler run. | |
37 | */ | |
38 | bool irq_wait_for_poll(struct irq_desc *desc) | |
39 | { | |
40 | if (WARN_ONCE(irq_poll_cpu == smp_processor_id(), | |
41 | "irq poll in progress on cpu %d for irq %d\n", | |
42 | smp_processor_id(), desc->irq_data.irq)) | |
43 | return false; | |
44 | ||
45 | #ifdef CONFIG_SMP | |
46 | do { | |
47 | raw_spin_unlock(&desc->lock); | |
32f4125e | 48 | while (irqd_irq_inprogress(&desc->irq_data)) |
fe200ae4 TG |
49 | cpu_relax(); |
50 | raw_spin_lock(&desc->lock); | |
a6aeddd1 | 51 | } while (irqd_irq_inprogress(&desc->irq_data)); |
fe200ae4 | 52 | /* Might have been disabled in meantime */ |
32f4125e | 53 | return !irqd_irq_disabled(&desc->irq_data) && desc->action; |
fe200ae4 TG |
54 | #else |
55 | return false; | |
56 | #endif | |
57 | } | |
58 | ||
0877d662 | 59 | |
200803df AC |
60 | /* |
61 | * Recovery handler for misrouted interrupts. | |
62 | */ | |
c7259cd7 | 63 | static int try_one_irq(int irq, struct irq_desc *desc, bool force) |
200803df | 64 | { |
0877d662 | 65 | irqreturn_t ret = IRQ_NONE; |
f84dbb91 | 66 | struct irqaction *action; |
200803df | 67 | |
239007b8 | 68 | raw_spin_lock(&desc->lock); |
c7259cd7 TG |
69 | |
70 | /* PER_CPU and nested thread interrupts are never polled */ | |
1ccb4e61 | 71 | if (irq_settings_is_per_cpu(desc) || irq_settings_is_nested_thread(desc)) |
c7259cd7 TG |
72 | goto out; |
73 | ||
74 | /* | |
75 | * Do not poll disabled interrupts unless the spurious | |
76 | * disabled poller asks explicitely. | |
77 | */ | |
32f4125e | 78 | if (irqd_irq_disabled(&desc->irq_data) && !force) |
c7259cd7 TG |
79 | goto out; |
80 | ||
81 | /* | |
82 | * All handlers must agree on IRQF_SHARED, so we test just the | |
83 | * first. Check for action->next as well. | |
84 | */ | |
85 | action = desc->action; | |
86 | if (!action || !(action->flags & IRQF_SHARED) || | |
52553ddf ED |
87 | (action->flags & __IRQF_TIMER) || |
88 | (action->handler(irq, action->dev_id) == IRQ_HANDLED) || | |
89 | !action->next) | |
c7259cd7 TG |
90 | goto out; |
91 | ||
f84dbb91 | 92 | /* Already running on another processor */ |
32f4125e | 93 | if (irqd_irq_inprogress(&desc->irq_data)) { |
f84dbb91 EB |
94 | /* |
95 | * Already running: If it is shared get the other | |
96 | * CPU to go looking for our mystery interrupt too | |
97 | */ | |
2a0d6fb3 | 98 | desc->istate |= IRQS_PENDING; |
fa27271b | 99 | goto out; |
c7259cd7 | 100 | } |
fa27271b | 101 | |
0877d662 | 102 | /* Mark it poll in progress */ |
6954b75b | 103 | desc->istate |= IRQS_POLL_INPROGRESS; |
fa27271b | 104 | do { |
0877d662 TG |
105 | if (handle_irq_event(desc) == IRQ_HANDLED) |
106 | ret = IRQ_HANDLED; | |
fa27271b | 107 | action = desc->action; |
2a0d6fb3 | 108 | } while ((desc->istate & IRQS_PENDING) && action); |
6954b75b | 109 | desc->istate &= ~IRQS_POLL_INPROGRESS; |
fa27271b TG |
110 | out: |
111 | raw_spin_unlock(&desc->lock); | |
0877d662 | 112 | return ret == IRQ_HANDLED; |
f84dbb91 EB |
113 | } |
114 | ||
115 | static int misrouted_irq(int irq) | |
116 | { | |
e00585bb | 117 | struct irq_desc *desc; |
d3c60047 | 118 | int i, ok = 0; |
f84dbb91 | 119 | |
c75d720f | 120 | if (atomic_inc_return(&irq_poll_active) != 1) |
d05c65ff TG |
121 | goto out; |
122 | ||
123 | irq_poll_cpu = smp_processor_id(); | |
124 | ||
e00585bb YL |
125 | for_each_irq_desc(i, desc) { |
126 | if (!i) | |
127 | continue; | |
f84dbb91 EB |
128 | |
129 | if (i == irq) /* Already tried */ | |
130 | continue; | |
131 | ||
c7259cd7 | 132 | if (try_one_irq(i, desc, false)) |
f84dbb91 | 133 | ok = 1; |
200803df | 134 | } |
d05c65ff TG |
135 | out: |
136 | atomic_dec(&irq_poll_active); | |
200803df AC |
137 | /* So the caller can adjust the irq error counts */ |
138 | return ok; | |
139 | } | |
140 | ||
663e6959 | 141 | static void poll_spurious_irqs(unsigned long dummy) |
f84dbb91 | 142 | { |
e00585bb | 143 | struct irq_desc *desc; |
d3c60047 | 144 | int i; |
e00585bb | 145 | |
d05c65ff TG |
146 | if (atomic_inc_return(&irq_poll_active) != 1) |
147 | goto out; | |
148 | irq_poll_cpu = smp_processor_id(); | |
149 | ||
e00585bb | 150 | for_each_irq_desc(i, desc) { |
7acdd53e | 151 | unsigned int state; |
f84dbb91 | 152 | |
e00585bb YL |
153 | if (!i) |
154 | continue; | |
155 | ||
f84dbb91 | 156 | /* Racy but it doesn't matter */ |
7acdd53e | 157 | state = desc->istate; |
f84dbb91 | 158 | barrier(); |
7acdd53e | 159 | if (!(state & IRQS_SPURIOUS_DISABLED)) |
f84dbb91 EB |
160 | continue; |
161 | ||
e7e7e0c0 | 162 | local_irq_disable(); |
c7259cd7 | 163 | try_one_irq(i, desc, true); |
e7e7e0c0 | 164 | local_irq_enable(); |
f84dbb91 | 165 | } |
d05c65ff TG |
166 | out: |
167 | atomic_dec(&irq_poll_active); | |
d3c60047 TG |
168 | mod_timer(&poll_spurious_irq_timer, |
169 | jiffies + POLL_SPURIOUS_IRQ_INTERVAL); | |
f84dbb91 EB |
170 | } |
171 | ||
3a43e05f SAS |
172 | static inline int bad_action_ret(irqreturn_t action_ret) |
173 | { | |
174 | if (likely(action_ret <= (IRQ_HANDLED | IRQ_WAKE_THREAD))) | |
175 | return 0; | |
176 | return 1; | |
177 | } | |
178 | ||
1da177e4 LT |
179 | /* |
180 | * If 99,900 of the previous 100,000 interrupts have not been handled | |
181 | * then assume that the IRQ is stuck in some manner. Drop a diagnostic | |
182 | * and try to turn the IRQ off. | |
183 | * | |
184 | * (The other 100-of-100,000 interrupts may have been a correctly | |
185 | * functioning device sharing an IRQ with the failing one) | |
1da177e4 | 186 | */ |
1da177e4 | 187 | static void |
34ffdb72 IM |
188 | __report_bad_irq(unsigned int irq, struct irq_desc *desc, |
189 | irqreturn_t action_ret) | |
1da177e4 LT |
190 | { |
191 | struct irqaction *action; | |
1082687e | 192 | unsigned long flags; |
1da177e4 | 193 | |
3a43e05f | 194 | if (bad_action_ret(action_ret)) { |
1da177e4 LT |
195 | printk(KERN_ERR "irq event %d: bogus return value %x\n", |
196 | irq, action_ret); | |
197 | } else { | |
200803df AC |
198 | printk(KERN_ERR "irq %d: nobody cared (try booting with " |
199 | "the \"irqpoll\" option)\n", irq); | |
1da177e4 LT |
200 | } |
201 | dump_stack(); | |
202 | printk(KERN_ERR "handlers:\n"); | |
06fcb0c6 | 203 | |
1082687e TG |
204 | /* |
205 | * We need to take desc->lock here. note_interrupt() is called | |
206 | * w/o desc->lock held, but IRQ_PROGRESS set. We might race | |
207 | * with something else removing an action. It's ok to take | |
208 | * desc->lock here. See synchronize_irq(). | |
209 | */ | |
210 | raw_spin_lock_irqsave(&desc->lock, flags); | |
1da177e4 LT |
211 | action = desc->action; |
212 | while (action) { | |
ef26f20c SAS |
213 | printk(KERN_ERR "[<%p>] %pf", action->handler, action->handler); |
214 | if (action->thread_fn) | |
215 | printk(KERN_CONT " threaded [<%p>] %pf", | |
216 | action->thread_fn, action->thread_fn); | |
217 | printk(KERN_CONT "\n"); | |
1da177e4 LT |
218 | action = action->next; |
219 | } | |
1082687e | 220 | raw_spin_unlock_irqrestore(&desc->lock, flags); |
1da177e4 LT |
221 | } |
222 | ||
06fcb0c6 | 223 | static void |
34ffdb72 | 224 | report_bad_irq(unsigned int irq, struct irq_desc *desc, irqreturn_t action_ret) |
1da177e4 LT |
225 | { |
226 | static int count = 100; | |
227 | ||
228 | if (count > 0) { | |
229 | count--; | |
230 | __report_bad_irq(irq, desc, action_ret); | |
231 | } | |
232 | } | |
233 | ||
d3c60047 TG |
234 | static inline int |
235 | try_misrouted_irq(unsigned int irq, struct irq_desc *desc, | |
236 | irqreturn_t action_ret) | |
92ea7727 LT |
237 | { |
238 | struct irqaction *action; | |
239 | ||
240 | if (!irqfixup) | |
241 | return 0; | |
242 | ||
243 | /* We didn't actually handle the IRQ - see if it was misrouted? */ | |
244 | if (action_ret == IRQ_NONE) | |
245 | return 1; | |
246 | ||
247 | /* | |
248 | * But for 'irqfixup == 2' we also do it for handled interrupts if | |
249 | * they are marked as IRQF_IRQPOLL (or for irq zero, which is the | |
250 | * traditional PC timer interrupt.. Legacy) | |
251 | */ | |
252 | if (irqfixup < 2) | |
253 | return 0; | |
254 | ||
255 | if (!irq) | |
256 | return 1; | |
257 | ||
258 | /* | |
259 | * Since we don't get the descriptor lock, "action" can | |
260 | * change under us. We don't really care, but we don't | |
261 | * want to follow a NULL pointer. So tell the compiler to | |
262 | * just load it once by using a barrier. | |
263 | */ | |
264 | action = desc->action; | |
265 | barrier(); | |
266 | return action && (action->flags & IRQF_IRQPOLL); | |
267 | } | |
268 | ||
34ffdb72 | 269 | void note_interrupt(unsigned int irq, struct irq_desc *desc, |
7d12e780 | 270 | irqreturn_t action_ret) |
1da177e4 | 271 | { |
6954b75b | 272 | if (desc->istate & IRQS_POLL_INPROGRESS) |
fe200ae4 TG |
273 | return; |
274 | ||
3a43e05f SAS |
275 | /* we get here again via the threaded handler */ |
276 | if (action_ret == IRQ_WAKE_THREAD) | |
277 | return; | |
278 | ||
279 | if (bad_action_ret(action_ret)) { | |
280 | report_bad_irq(irq, desc, action_ret); | |
281 | return; | |
282 | } | |
283 | ||
284 | if (unlikely(action_ret == IRQ_NONE)) { | |
4f27c00b AC |
285 | /* |
286 | * If we are seeing only the odd spurious IRQ caused by | |
287 | * bus asynchronicity then don't eventually trigger an error, | |
fbfecd37 | 288 | * otherwise the counter becomes a doomsday timer for otherwise |
4f27c00b AC |
289 | * working systems |
290 | */ | |
188fd89d | 291 | if (time_after(jiffies, desc->last_unhandled + HZ/10)) |
4f27c00b AC |
292 | desc->irqs_unhandled = 1; |
293 | else | |
294 | desc->irqs_unhandled++; | |
295 | desc->last_unhandled = jiffies; | |
1da177e4 LT |
296 | } |
297 | ||
92ea7727 LT |
298 | if (unlikely(try_misrouted_irq(irq, desc, action_ret))) { |
299 | int ok = misrouted_irq(irq); | |
300 | if (action_ret == IRQ_NONE) | |
301 | desc->irqs_unhandled -= ok; | |
200803df AC |
302 | } |
303 | ||
1da177e4 | 304 | desc->irq_count++; |
83d4e6e7 | 305 | if (likely(desc->irq_count < 100000)) |
1da177e4 LT |
306 | return; |
307 | ||
308 | desc->irq_count = 0; | |
83d4e6e7 | 309 | if (unlikely(desc->irqs_unhandled > 99900)) { |
1da177e4 LT |
310 | /* |
311 | * The interrupt is stuck | |
312 | */ | |
313 | __report_bad_irq(irq, desc, action_ret); | |
314 | /* | |
315 | * Now kill the IRQ | |
316 | */ | |
317 | printk(KERN_EMERG "Disabling IRQ #%d\n", irq); | |
7acdd53e | 318 | desc->istate |= IRQS_SPURIOUS_DISABLED; |
1adb0850 | 319 | desc->depth++; |
87923470 | 320 | irq_disable(desc); |
f84dbb91 | 321 | |
d3c60047 TG |
322 | mod_timer(&poll_spurious_irq_timer, |
323 | jiffies + POLL_SPURIOUS_IRQ_INTERVAL); | |
1da177e4 LT |
324 | } |
325 | desc->irqs_unhandled = 0; | |
326 | } | |
327 | ||
2329abfa | 328 | bool noirqdebug __read_mostly; |
1da177e4 | 329 | |
343cde51 | 330 | int noirqdebug_setup(char *str) |
1da177e4 LT |
331 | { |
332 | noirqdebug = 1; | |
333 | printk(KERN_INFO "IRQ lockup detection disabled\n"); | |
06fcb0c6 | 334 | |
1da177e4 LT |
335 | return 1; |
336 | } | |
337 | ||
338 | __setup("noirqdebug", noirqdebug_setup); | |
9e094c17 AK |
339 | module_param(noirqdebug, bool, 0644); |
340 | MODULE_PARM_DESC(noirqdebug, "Disable irq lockup detection when true"); | |
1da177e4 | 341 | |
200803df AC |
342 | static int __init irqfixup_setup(char *str) |
343 | { | |
344 | irqfixup = 1; | |
345 | printk(KERN_WARNING "Misrouted IRQ fixup support enabled.\n"); | |
346 | printk(KERN_WARNING "This may impact system performance.\n"); | |
06fcb0c6 | 347 | |
200803df AC |
348 | return 1; |
349 | } | |
350 | ||
351 | __setup("irqfixup", irqfixup_setup); | |
9e094c17 | 352 | module_param(irqfixup, int, 0644); |
200803df AC |
353 | |
354 | static int __init irqpoll_setup(char *str) | |
355 | { | |
356 | irqfixup = 2; | |
357 | printk(KERN_WARNING "Misrouted IRQ fixup and polling support " | |
358 | "enabled\n"); | |
359 | printk(KERN_WARNING "This may significantly impact system " | |
360 | "performance\n"); | |
361 | return 1; | |
362 | } | |
363 | ||
364 | __setup("irqpoll", irqpoll_setup); |