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); | |
009b4c3b | 48 | while (desc->istate & IRQS_INPROGRESS) |
fe200ae4 TG |
49 | cpu_relax(); |
50 | raw_spin_lock(&desc->lock); | |
009b4c3b | 51 | } while (desc->istate & IRQS_INPROGRESS); |
fe200ae4 | 52 | /* Might have been disabled in meantime */ |
c1594b77 | 53 | return !(desc->istate & IRQS_DISABLED) && 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 */ | |
a005677b TG |
71 | if (irq_settings_is_per_cpu(desc) || |
72 | (desc->status & IRQ_NESTED_THREAD)) | |
c7259cd7 TG |
73 | goto out; |
74 | ||
75 | /* | |
76 | * Do not poll disabled interrupts unless the spurious | |
77 | * disabled poller asks explicitely. | |
78 | */ | |
c1594b77 | 79 | if ((desc->istate & IRQS_DISABLED) && !force) |
c7259cd7 TG |
80 | goto out; |
81 | ||
82 | /* | |
83 | * All handlers must agree on IRQF_SHARED, so we test just the | |
84 | * first. Check for action->next as well. | |
85 | */ | |
86 | action = desc->action; | |
87 | if (!action || !(action->flags & IRQF_SHARED) || | |
88 | (action->flags & __IRQF_TIMER) || !action->next) | |
89 | goto out; | |
90 | ||
f84dbb91 | 91 | /* Already running on another processor */ |
009b4c3b | 92 | if (desc->istate & IRQS_INPROGRESS) { |
f84dbb91 EB |
93 | /* |
94 | * Already running: If it is shared get the other | |
95 | * CPU to go looking for our mystery interrupt too | |
96 | */ | |
2a0d6fb3 TG |
97 | irq_compat_set_pending(desc); |
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 | |
d05c65ff TG |
120 | if (atomic_inc_return(&irq_poll_active) == 1) |
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 | ||
1da177e4 LT |
172 | /* |
173 | * If 99,900 of the previous 100,000 interrupts have not been handled | |
174 | * then assume that the IRQ is stuck in some manner. Drop a diagnostic | |
175 | * and try to turn the IRQ off. | |
176 | * | |
177 | * (The other 100-of-100,000 interrupts may have been a correctly | |
178 | * functioning device sharing an IRQ with the failing one) | |
1da177e4 | 179 | */ |
1da177e4 | 180 | static void |
34ffdb72 IM |
181 | __report_bad_irq(unsigned int irq, struct irq_desc *desc, |
182 | irqreturn_t action_ret) | |
1da177e4 LT |
183 | { |
184 | struct irqaction *action; | |
1082687e | 185 | unsigned long flags; |
1da177e4 LT |
186 | |
187 | if (action_ret != IRQ_HANDLED && action_ret != IRQ_NONE) { | |
188 | printk(KERN_ERR "irq event %d: bogus return value %x\n", | |
189 | irq, action_ret); | |
190 | } else { | |
200803df AC |
191 | printk(KERN_ERR "irq %d: nobody cared (try booting with " |
192 | "the \"irqpoll\" option)\n", irq); | |
1da177e4 LT |
193 | } |
194 | dump_stack(); | |
195 | printk(KERN_ERR "handlers:\n"); | |
06fcb0c6 | 196 | |
1082687e TG |
197 | /* |
198 | * We need to take desc->lock here. note_interrupt() is called | |
199 | * w/o desc->lock held, but IRQ_PROGRESS set. We might race | |
200 | * with something else removing an action. It's ok to take | |
201 | * desc->lock here. See synchronize_irq(). | |
202 | */ | |
203 | raw_spin_lock_irqsave(&desc->lock, flags); | |
1da177e4 LT |
204 | action = desc->action; |
205 | while (action) { | |
206 | printk(KERN_ERR "[<%p>]", action->handler); | |
207 | print_symbol(" (%s)", | |
208 | (unsigned long)action->handler); | |
209 | printk("\n"); | |
210 | action = action->next; | |
211 | } | |
1082687e | 212 | raw_spin_unlock_irqrestore(&desc->lock, flags); |
1da177e4 LT |
213 | } |
214 | ||
06fcb0c6 | 215 | static void |
34ffdb72 | 216 | report_bad_irq(unsigned int irq, struct irq_desc *desc, irqreturn_t action_ret) |
1da177e4 LT |
217 | { |
218 | static int count = 100; | |
219 | ||
220 | if (count > 0) { | |
221 | count--; | |
222 | __report_bad_irq(irq, desc, action_ret); | |
223 | } | |
224 | } | |
225 | ||
d3c60047 TG |
226 | static inline int |
227 | try_misrouted_irq(unsigned int irq, struct irq_desc *desc, | |
228 | irqreturn_t action_ret) | |
92ea7727 LT |
229 | { |
230 | struct irqaction *action; | |
231 | ||
232 | if (!irqfixup) | |
233 | return 0; | |
234 | ||
235 | /* We didn't actually handle the IRQ - see if it was misrouted? */ | |
236 | if (action_ret == IRQ_NONE) | |
237 | return 1; | |
238 | ||
239 | /* | |
240 | * But for 'irqfixup == 2' we also do it for handled interrupts if | |
241 | * they are marked as IRQF_IRQPOLL (or for irq zero, which is the | |
242 | * traditional PC timer interrupt.. Legacy) | |
243 | */ | |
244 | if (irqfixup < 2) | |
245 | return 0; | |
246 | ||
247 | if (!irq) | |
248 | return 1; | |
249 | ||
250 | /* | |
251 | * Since we don't get the descriptor lock, "action" can | |
252 | * change under us. We don't really care, but we don't | |
253 | * want to follow a NULL pointer. So tell the compiler to | |
254 | * just load it once by using a barrier. | |
255 | */ | |
256 | action = desc->action; | |
257 | barrier(); | |
258 | return action && (action->flags & IRQF_IRQPOLL); | |
259 | } | |
260 | ||
34ffdb72 | 261 | void note_interrupt(unsigned int irq, struct irq_desc *desc, |
7d12e780 | 262 | irqreturn_t action_ret) |
1da177e4 | 263 | { |
6954b75b | 264 | if (desc->istate & IRQS_POLL_INPROGRESS) |
fe200ae4 TG |
265 | return; |
266 | ||
83d4e6e7 | 267 | if (unlikely(action_ret != IRQ_HANDLED)) { |
4f27c00b AC |
268 | /* |
269 | * If we are seeing only the odd spurious IRQ caused by | |
270 | * bus asynchronicity then don't eventually trigger an error, | |
fbfecd37 | 271 | * otherwise the counter becomes a doomsday timer for otherwise |
4f27c00b AC |
272 | * working systems |
273 | */ | |
188fd89d | 274 | if (time_after(jiffies, desc->last_unhandled + HZ/10)) |
4f27c00b AC |
275 | desc->irqs_unhandled = 1; |
276 | else | |
277 | desc->irqs_unhandled++; | |
278 | desc->last_unhandled = jiffies; | |
83d4e6e7 | 279 | if (unlikely(action_ret != IRQ_NONE)) |
1da177e4 LT |
280 | report_bad_irq(irq, desc, action_ret); |
281 | } | |
282 | ||
92ea7727 LT |
283 | if (unlikely(try_misrouted_irq(irq, desc, action_ret))) { |
284 | int ok = misrouted_irq(irq); | |
285 | if (action_ret == IRQ_NONE) | |
286 | desc->irqs_unhandled -= ok; | |
200803df AC |
287 | } |
288 | ||
1da177e4 | 289 | desc->irq_count++; |
83d4e6e7 | 290 | if (likely(desc->irq_count < 100000)) |
1da177e4 LT |
291 | return; |
292 | ||
293 | desc->irq_count = 0; | |
83d4e6e7 | 294 | if (unlikely(desc->irqs_unhandled > 99900)) { |
1da177e4 LT |
295 | /* |
296 | * The interrupt is stuck | |
297 | */ | |
298 | __report_bad_irq(irq, desc, action_ret); | |
299 | /* | |
300 | * Now kill the IRQ | |
301 | */ | |
302 | printk(KERN_EMERG "Disabling IRQ #%d\n", irq); | |
7acdd53e | 303 | desc->istate |= IRQS_SPURIOUS_DISABLED; |
1adb0850 | 304 | desc->depth++; |
87923470 | 305 | irq_disable(desc); |
f84dbb91 | 306 | |
d3c60047 TG |
307 | mod_timer(&poll_spurious_irq_timer, |
308 | jiffies + POLL_SPURIOUS_IRQ_INTERVAL); | |
1da177e4 LT |
309 | } |
310 | desc->irqs_unhandled = 0; | |
311 | } | |
312 | ||
83d4e6e7 | 313 | int noirqdebug __read_mostly; |
1da177e4 | 314 | |
343cde51 | 315 | int noirqdebug_setup(char *str) |
1da177e4 LT |
316 | { |
317 | noirqdebug = 1; | |
318 | printk(KERN_INFO "IRQ lockup detection disabled\n"); | |
06fcb0c6 | 319 | |
1da177e4 LT |
320 | return 1; |
321 | } | |
322 | ||
323 | __setup("noirqdebug", noirqdebug_setup); | |
9e094c17 AK |
324 | module_param(noirqdebug, bool, 0644); |
325 | MODULE_PARM_DESC(noirqdebug, "Disable irq lockup detection when true"); | |
1da177e4 | 326 | |
200803df AC |
327 | static int __init irqfixup_setup(char *str) |
328 | { | |
329 | irqfixup = 1; | |
330 | printk(KERN_WARNING "Misrouted IRQ fixup support enabled.\n"); | |
331 | printk(KERN_WARNING "This may impact system performance.\n"); | |
06fcb0c6 | 332 | |
200803df AC |
333 | return 1; |
334 | } | |
335 | ||
336 | __setup("irqfixup", irqfixup_setup); | |
9e094c17 | 337 | module_param(irqfixup, int, 0644); |
200803df AC |
338 | |
339 | static int __init irqpoll_setup(char *str) | |
340 | { | |
341 | irqfixup = 2; | |
342 | printk(KERN_WARNING "Misrouted IRQ fixup and polling support " | |
343 | "enabled\n"); | |
344 | printk(KERN_WARNING "This may significantly impact system " | |
345 | "performance\n"); | |
346 | return 1; | |
347 | } | |
348 | ||
349 | __setup("irqpoll", irqpoll_setup); |