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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); | |
48 | while (desc->status & IRQ_INPROGRESS) | |
49 | cpu_relax(); | |
50 | raw_spin_lock(&desc->lock); | |
51 | } while (desc->status & IRQ_INPROGRESS); | |
52 | /* Might have been disabled in meantime */ | |
53 | return !(desc->status & IRQ_DISABLED) && desc->action; | |
54 | #else | |
55 | return false; | |
56 | #endif | |
57 | } | |
58 | ||
200803df AC |
59 | /* |
60 | * Recovery handler for misrouted interrupts. | |
61 | */ | |
c7259cd7 | 62 | static int try_one_irq(int irq, struct irq_desc *desc, bool force) |
200803df | 63 | { |
f84dbb91 | 64 | struct irqaction *action; |
fe200ae4 | 65 | int ok = 0; |
200803df | 66 | |
239007b8 | 67 | raw_spin_lock(&desc->lock); |
c7259cd7 TG |
68 | |
69 | /* PER_CPU and nested thread interrupts are never polled */ | |
70 | if (desc->status & (IRQ_PER_CPU | IRQ_NESTED_THREAD)) | |
71 | goto out; | |
72 | ||
73 | /* | |
74 | * Do not poll disabled interrupts unless the spurious | |
75 | * disabled poller asks explicitely. | |
76 | */ | |
77 | if ((desc->status & IRQ_DISABLED) && !force) | |
78 | goto out; | |
79 | ||
80 | /* | |
81 | * All handlers must agree on IRQF_SHARED, so we test just the | |
82 | * first. Check for action->next as well. | |
83 | */ | |
84 | action = desc->action; | |
85 | if (!action || !(action->flags & IRQF_SHARED) || | |
86 | (action->flags & __IRQF_TIMER) || !action->next) | |
87 | goto out; | |
88 | ||
f84dbb91 EB |
89 | /* Already running on another processor */ |
90 | if (desc->status & IRQ_INPROGRESS) { | |
91 | /* | |
92 | * Already running: If it is shared get the other | |
93 | * CPU to go looking for our mystery interrupt too | |
94 | */ | |
c7259cd7 | 95 | desc->status |= IRQ_PENDING; |
fa27271b | 96 | goto out; |
c7259cd7 | 97 | } |
fa27271b | 98 | |
fe200ae4 TG |
99 | /* Honour the normal IRQ locking and mark it poll in progress */ |
100 | desc->status |= IRQ_INPROGRESS | IRQ_POLL_INPROGRESS; | |
fa27271b | 101 | do { |
fa27271b | 102 | desc->status &= ~IRQ_PENDING; |
239007b8 | 103 | raw_spin_unlock(&desc->lock); |
fa27271b TG |
104 | if (handle_IRQ_event(irq, action) != IRQ_NONE) |
105 | ok = 1; | |
239007b8 | 106 | raw_spin_lock(&desc->lock); |
fa27271b TG |
107 | action = desc->action; |
108 | } while ((desc->status & IRQ_PENDING) && action); | |
109 | ||
fe200ae4 | 110 | desc->status &= ~(IRQ_INPROGRESS | IRQ_POLL_INPROGRESS); |
fa27271b TG |
111 | out: |
112 | raw_spin_unlock(&desc->lock); | |
f84dbb91 EB |
113 | return ok; |
114 | } | |
115 | ||
116 | static int misrouted_irq(int irq) | |
117 | { | |
e00585bb | 118 | struct irq_desc *desc; |
d3c60047 | 119 | int i, ok = 0; |
f84dbb91 | 120 | |
d05c65ff TG |
121 | if (atomic_inc_return(&irq_poll_active) == 1) |
122 | goto out; | |
123 | ||
124 | irq_poll_cpu = smp_processor_id(); | |
125 | ||
e00585bb YL |
126 | for_each_irq_desc(i, desc) { |
127 | if (!i) | |
128 | continue; | |
f84dbb91 EB |
129 | |
130 | if (i == irq) /* Already tried */ | |
131 | continue; | |
132 | ||
c7259cd7 | 133 | if (try_one_irq(i, desc, false)) |
f84dbb91 | 134 | ok = 1; |
200803df | 135 | } |
d05c65ff TG |
136 | out: |
137 | atomic_dec(&irq_poll_active); | |
200803df AC |
138 | /* So the caller can adjust the irq error counts */ |
139 | return ok; | |
140 | } | |
141 | ||
663e6959 | 142 | static void poll_spurious_irqs(unsigned long dummy) |
f84dbb91 | 143 | { |
e00585bb | 144 | struct irq_desc *desc; |
d3c60047 | 145 | int i; |
e00585bb | 146 | |
d05c65ff TG |
147 | if (atomic_inc_return(&irq_poll_active) != 1) |
148 | goto out; | |
149 | irq_poll_cpu = smp_processor_id(); | |
150 | ||
e00585bb | 151 | for_each_irq_desc(i, desc) { |
f84dbb91 EB |
152 | unsigned int status; |
153 | ||
e00585bb YL |
154 | if (!i) |
155 | continue; | |
156 | ||
f84dbb91 EB |
157 | /* Racy but it doesn't matter */ |
158 | status = desc->status; | |
159 | barrier(); | |
160 | if (!(status & IRQ_SPURIOUS_DISABLED)) | |
161 | continue; | |
162 | ||
e7e7e0c0 | 163 | local_irq_disable(); |
c7259cd7 | 164 | try_one_irq(i, desc, true); |
e7e7e0c0 | 165 | local_irq_enable(); |
f84dbb91 | 166 | } |
d05c65ff TG |
167 | out: |
168 | atomic_dec(&irq_poll_active); | |
d3c60047 TG |
169 | mod_timer(&poll_spurious_irq_timer, |
170 | jiffies + POLL_SPURIOUS_IRQ_INTERVAL); | |
f84dbb91 EB |
171 | } |
172 | ||
1da177e4 LT |
173 | /* |
174 | * If 99,900 of the previous 100,000 interrupts have not been handled | |
175 | * then assume that the IRQ is stuck in some manner. Drop a diagnostic | |
176 | * and try to turn the IRQ off. | |
177 | * | |
178 | * (The other 100-of-100,000 interrupts may have been a correctly | |
179 | * functioning device sharing an IRQ with the failing one) | |
1da177e4 | 180 | */ |
1da177e4 | 181 | static void |
34ffdb72 IM |
182 | __report_bad_irq(unsigned int irq, struct irq_desc *desc, |
183 | irqreturn_t action_ret) | |
1da177e4 LT |
184 | { |
185 | struct irqaction *action; | |
1082687e | 186 | unsigned long flags; |
1da177e4 LT |
187 | |
188 | if (action_ret != IRQ_HANDLED && action_ret != IRQ_NONE) { | |
189 | printk(KERN_ERR "irq event %d: bogus return value %x\n", | |
190 | irq, action_ret); | |
191 | } else { | |
200803df AC |
192 | printk(KERN_ERR "irq %d: nobody cared (try booting with " |
193 | "the \"irqpoll\" option)\n", irq); | |
1da177e4 LT |
194 | } |
195 | dump_stack(); | |
196 | printk(KERN_ERR "handlers:\n"); | |
06fcb0c6 | 197 | |
1082687e TG |
198 | /* |
199 | * We need to take desc->lock here. note_interrupt() is called | |
200 | * w/o desc->lock held, but IRQ_PROGRESS set. We might race | |
201 | * with something else removing an action. It's ok to take | |
202 | * desc->lock here. See synchronize_irq(). | |
203 | */ | |
204 | raw_spin_lock_irqsave(&desc->lock, flags); | |
1da177e4 LT |
205 | action = desc->action; |
206 | while (action) { | |
207 | printk(KERN_ERR "[<%p>]", action->handler); | |
208 | print_symbol(" (%s)", | |
209 | (unsigned long)action->handler); | |
210 | printk("\n"); | |
211 | action = action->next; | |
212 | } | |
1082687e | 213 | raw_spin_unlock_irqrestore(&desc->lock, flags); |
1da177e4 LT |
214 | } |
215 | ||
06fcb0c6 | 216 | static void |
34ffdb72 | 217 | report_bad_irq(unsigned int irq, struct irq_desc *desc, irqreturn_t action_ret) |
1da177e4 LT |
218 | { |
219 | static int count = 100; | |
220 | ||
221 | if (count > 0) { | |
222 | count--; | |
223 | __report_bad_irq(irq, desc, action_ret); | |
224 | } | |
225 | } | |
226 | ||
d3c60047 TG |
227 | static inline int |
228 | try_misrouted_irq(unsigned int irq, struct irq_desc *desc, | |
229 | irqreturn_t action_ret) | |
92ea7727 LT |
230 | { |
231 | struct irqaction *action; | |
232 | ||
233 | if (!irqfixup) | |
234 | return 0; | |
235 | ||
236 | /* We didn't actually handle the IRQ - see if it was misrouted? */ | |
237 | if (action_ret == IRQ_NONE) | |
238 | return 1; | |
239 | ||
240 | /* | |
241 | * But for 'irqfixup == 2' we also do it for handled interrupts if | |
242 | * they are marked as IRQF_IRQPOLL (or for irq zero, which is the | |
243 | * traditional PC timer interrupt.. Legacy) | |
244 | */ | |
245 | if (irqfixup < 2) | |
246 | return 0; | |
247 | ||
248 | if (!irq) | |
249 | return 1; | |
250 | ||
251 | /* | |
252 | * Since we don't get the descriptor lock, "action" can | |
253 | * change under us. We don't really care, but we don't | |
254 | * want to follow a NULL pointer. So tell the compiler to | |
255 | * just load it once by using a barrier. | |
256 | */ | |
257 | action = desc->action; | |
258 | barrier(); | |
259 | return action && (action->flags & IRQF_IRQPOLL); | |
260 | } | |
261 | ||
34ffdb72 | 262 | void note_interrupt(unsigned int irq, struct irq_desc *desc, |
7d12e780 | 263 | irqreturn_t action_ret) |
1da177e4 | 264 | { |
fe200ae4 TG |
265 | if (desc->status & IRQ_POLL_INPROGRESS) |
266 | return; | |
267 | ||
83d4e6e7 | 268 | if (unlikely(action_ret != IRQ_HANDLED)) { |
4f27c00b AC |
269 | /* |
270 | * If we are seeing only the odd spurious IRQ caused by | |
271 | * bus asynchronicity then don't eventually trigger an error, | |
fbfecd37 | 272 | * otherwise the counter becomes a doomsday timer for otherwise |
4f27c00b AC |
273 | * working systems |
274 | */ | |
188fd89d | 275 | if (time_after(jiffies, desc->last_unhandled + HZ/10)) |
4f27c00b AC |
276 | desc->irqs_unhandled = 1; |
277 | else | |
278 | desc->irqs_unhandled++; | |
279 | desc->last_unhandled = jiffies; | |
83d4e6e7 | 280 | if (unlikely(action_ret != IRQ_NONE)) |
1da177e4 LT |
281 | report_bad_irq(irq, desc, action_ret); |
282 | } | |
283 | ||
92ea7727 LT |
284 | if (unlikely(try_misrouted_irq(irq, desc, action_ret))) { |
285 | int ok = misrouted_irq(irq); | |
286 | if (action_ret == IRQ_NONE) | |
287 | desc->irqs_unhandled -= ok; | |
200803df AC |
288 | } |
289 | ||
1da177e4 | 290 | desc->irq_count++; |
83d4e6e7 | 291 | if (likely(desc->irq_count < 100000)) |
1da177e4 LT |
292 | return; |
293 | ||
294 | desc->irq_count = 0; | |
83d4e6e7 | 295 | if (unlikely(desc->irqs_unhandled > 99900)) { |
1da177e4 LT |
296 | /* |
297 | * The interrupt is stuck | |
298 | */ | |
299 | __report_bad_irq(irq, desc, action_ret); | |
300 | /* | |
301 | * Now kill the IRQ | |
302 | */ | |
303 | printk(KERN_EMERG "Disabling IRQ #%d\n", irq); | |
1adb0850 TG |
304 | desc->status |= IRQ_DISABLED | IRQ_SPURIOUS_DISABLED; |
305 | desc->depth++; | |
bc310dda | 306 | desc->irq_data.chip->irq_disable(&desc->irq_data); |
f84dbb91 | 307 | |
d3c60047 TG |
308 | mod_timer(&poll_spurious_irq_timer, |
309 | jiffies + POLL_SPURIOUS_IRQ_INTERVAL); | |
1da177e4 LT |
310 | } |
311 | desc->irqs_unhandled = 0; | |
312 | } | |
313 | ||
83d4e6e7 | 314 | int noirqdebug __read_mostly; |
1da177e4 | 315 | |
343cde51 | 316 | int noirqdebug_setup(char *str) |
1da177e4 LT |
317 | { |
318 | noirqdebug = 1; | |
319 | printk(KERN_INFO "IRQ lockup detection disabled\n"); | |
06fcb0c6 | 320 | |
1da177e4 LT |
321 | return 1; |
322 | } | |
323 | ||
324 | __setup("noirqdebug", noirqdebug_setup); | |
9e094c17 AK |
325 | module_param(noirqdebug, bool, 0644); |
326 | MODULE_PARM_DESC(noirqdebug, "Disable irq lockup detection when true"); | |
1da177e4 | 327 | |
200803df AC |
328 | static int __init irqfixup_setup(char *str) |
329 | { | |
330 | irqfixup = 1; | |
331 | printk(KERN_WARNING "Misrouted IRQ fixup support enabled.\n"); | |
332 | printk(KERN_WARNING "This may impact system performance.\n"); | |
06fcb0c6 | 333 | |
200803df AC |
334 | return 1; |
335 | } | |
336 | ||
337 | __setup("irqfixup", irqfixup_setup); | |
9e094c17 | 338 | module_param(irqfixup, int, 0644); |
200803df AC |
339 | |
340 | static int __init irqpoll_setup(char *str) | |
341 | { | |
342 | irqfixup = 2; | |
343 | printk(KERN_WARNING "Misrouted IRQ fixup and polling support " | |
344 | "enabled\n"); | |
345 | printk(KERN_WARNING "This may significantly impact system " | |
346 | "performance\n"); | |
347 | return 1; | |
348 | } | |
349 | ||
350 | __setup("irqpoll", irqpoll_setup); |