cpumask: update irq_desc to use cpumask_var_t
[linux-2.6.git] / kernel / irq / spurious.c
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
9 #include <linux/jiffies.h>
10 #include <linux/irq.h>
11 #include <linux/module.h>
12 #include <linux/kallsyms.h>
13 #include <linux/interrupt.h>
14 #include <linux/moduleparam.h>
15 #include <linux/timer.h>
16
17 static int irqfixup __read_mostly;
18
19 #define POLL_SPURIOUS_IRQ_INTERVAL (HZ/10)
20 static void poll_spurious_irqs(unsigned long dummy);
21 static DEFINE_TIMER(poll_spurious_irq_timer, poll_spurious_irqs, 0, 0);
22
23 /*
24  * Recovery handler for misrouted interrupts.
25  */
26 static int try_one_irq(int irq, struct irq_desc *desc)
27 {
28         struct irqaction *action;
29         int ok = 0, work = 0;
30
31         spin_lock(&desc->lock);
32         /* Already running on another processor */
33         if (desc->status & IRQ_INPROGRESS) {
34                 /*
35                  * Already running: If it is shared get the other
36                  * CPU to go looking for our mystery interrupt too
37                  */
38                 if (desc->action && (desc->action->flags & IRQF_SHARED))
39                         desc->status |= IRQ_PENDING;
40                 spin_unlock(&desc->lock);
41                 return ok;
42         }
43         /* Honour the normal IRQ locking */
44         desc->status |= IRQ_INPROGRESS;
45         action = desc->action;
46         spin_unlock(&desc->lock);
47
48         while (action) {
49                 /* Only shared IRQ handlers are safe to call */
50                 if (action->flags & IRQF_SHARED) {
51                         if (action->handler(irq, action->dev_id) ==
52                                 IRQ_HANDLED)
53                                 ok = 1;
54                 }
55                 action = action->next;
56         }
57         local_irq_disable();
58         /* Now clean up the flags */
59         spin_lock(&desc->lock);
60         action = desc->action;
61
62         /*
63          * While we were looking for a fixup someone queued a real
64          * IRQ clashing with our walk:
65          */
66         while ((desc->status & IRQ_PENDING) && action) {
67                 /*
68                  * Perform real IRQ processing for the IRQ we deferred
69                  */
70                 work = 1;
71                 spin_unlock(&desc->lock);
72                 handle_IRQ_event(irq, action);
73                 spin_lock(&desc->lock);
74                 desc->status &= ~IRQ_PENDING;
75         }
76         desc->status &= ~IRQ_INPROGRESS;
77         /*
78          * If we did actual work for the real IRQ line we must let the
79          * IRQ controller clean up too
80          */
81         if (work && desc->chip && desc->chip->end)
82                 desc->chip->end(irq);
83         spin_unlock(&desc->lock);
84
85         return ok;
86 }
87
88 static int misrouted_irq(int irq)
89 {
90         struct irq_desc *desc;
91         int i, ok = 0;
92
93         for_each_irq_desc(i, desc) {
94                 if (!i)
95                          continue;
96
97                 if (i == irq)   /* Already tried */
98                         continue;
99
100                 if (try_one_irq(i, desc))
101                         ok = 1;
102         }
103         /* So the caller can adjust the irq error counts */
104         return ok;
105 }
106
107 static void poll_spurious_irqs(unsigned long dummy)
108 {
109         struct irq_desc *desc;
110         int i;
111
112         for_each_irq_desc(i, desc) {
113                 unsigned int status;
114
115                 if (!i)
116                          continue;
117
118                 /* Racy but it doesn't matter */
119                 status = desc->status;
120                 barrier();
121                 if (!(status & IRQ_SPURIOUS_DISABLED))
122                         continue;
123
124                 try_one_irq(i, desc);
125         }
126
127         mod_timer(&poll_spurious_irq_timer,
128                   jiffies + POLL_SPURIOUS_IRQ_INTERVAL);
129 }
130
131 /*
132  * If 99,900 of the previous 100,000 interrupts have not been handled
133  * then assume that the IRQ is stuck in some manner. Drop a diagnostic
134  * and try to turn the IRQ off.
135  *
136  * (The other 100-of-100,000 interrupts may have been a correctly
137  *  functioning device sharing an IRQ with the failing one)
138  *
139  * Called under desc->lock
140  */
141
142 static void
143 __report_bad_irq(unsigned int irq, struct irq_desc *desc,
144                  irqreturn_t action_ret)
145 {
146         struct irqaction *action;
147
148         if (action_ret != IRQ_HANDLED && action_ret != IRQ_NONE) {
149                 printk(KERN_ERR "irq event %d: bogus return value %x\n",
150                                 irq, action_ret);
151         } else {
152                 printk(KERN_ERR "irq %d: nobody cared (try booting with "
153                                 "the \"irqpoll\" option)\n", irq);
154         }
155         dump_stack();
156         printk(KERN_ERR "handlers:\n");
157
158         action = desc->action;
159         while (action) {
160                 printk(KERN_ERR "[<%p>]", action->handler);
161                 print_symbol(" (%s)",
162                         (unsigned long)action->handler);
163                 printk("\n");
164                 action = action->next;
165         }
166 }
167
168 static void
169 report_bad_irq(unsigned int irq, struct irq_desc *desc, irqreturn_t action_ret)
170 {
171         static int count = 100;
172
173         if (count > 0) {
174                 count--;
175                 __report_bad_irq(irq, desc, action_ret);
176         }
177 }
178
179 static inline int
180 try_misrouted_irq(unsigned int irq, struct irq_desc *desc,
181                   irqreturn_t action_ret)
182 {
183         struct irqaction *action;
184
185         if (!irqfixup)
186                 return 0;
187
188         /* We didn't actually handle the IRQ - see if it was misrouted? */
189         if (action_ret == IRQ_NONE)
190                 return 1;
191
192         /*
193          * But for 'irqfixup == 2' we also do it for handled interrupts if
194          * they are marked as IRQF_IRQPOLL (or for irq zero, which is the
195          * traditional PC timer interrupt.. Legacy)
196          */
197         if (irqfixup < 2)
198                 return 0;
199
200         if (!irq)
201                 return 1;
202
203         /*
204          * Since we don't get the descriptor lock, "action" can
205          * change under us.  We don't really care, but we don't
206          * want to follow a NULL pointer. So tell the compiler to
207          * just load it once by using a barrier.
208          */
209         action = desc->action;
210         barrier();
211         return action && (action->flags & IRQF_IRQPOLL);
212 }
213
214 void note_interrupt(unsigned int irq, struct irq_desc *desc,
215                     irqreturn_t action_ret)
216 {
217         if (unlikely(action_ret != IRQ_HANDLED)) {
218                 /*
219                  * If we are seeing only the odd spurious IRQ caused by
220                  * bus asynchronicity then don't eventually trigger an error,
221                  * otherwise the couter becomes a doomsday timer for otherwise
222                  * working systems
223                  */
224                 if (time_after(jiffies, desc->last_unhandled + HZ/10))
225                         desc->irqs_unhandled = 1;
226                 else
227                         desc->irqs_unhandled++;
228                 desc->last_unhandled = jiffies;
229                 if (unlikely(action_ret != IRQ_NONE))
230                         report_bad_irq(irq, desc, action_ret);
231         }
232
233         if (unlikely(try_misrouted_irq(irq, desc, action_ret))) {
234                 int ok = misrouted_irq(irq);
235                 if (action_ret == IRQ_NONE)
236                         desc->irqs_unhandled -= ok;
237         }
238
239         desc->irq_count++;
240         if (likely(desc->irq_count < 100000))
241                 return;
242
243         desc->irq_count = 0;
244         if (unlikely(desc->irqs_unhandled > 99900)) {
245                 /*
246                  * The interrupt is stuck
247                  */
248                 __report_bad_irq(irq, desc, action_ret);
249                 /*
250                  * Now kill the IRQ
251                  */
252                 printk(KERN_EMERG "Disabling IRQ #%d\n", irq);
253                 desc->status |= IRQ_DISABLED | IRQ_SPURIOUS_DISABLED;
254                 desc->depth++;
255                 desc->chip->disable(irq);
256
257                 mod_timer(&poll_spurious_irq_timer,
258                           jiffies + POLL_SPURIOUS_IRQ_INTERVAL);
259         }
260         desc->irqs_unhandled = 0;
261 }
262
263 int noirqdebug __read_mostly;
264
265 int noirqdebug_setup(char *str)
266 {
267         noirqdebug = 1;
268         printk(KERN_INFO "IRQ lockup detection disabled\n");
269
270         return 1;
271 }
272
273 __setup("noirqdebug", noirqdebug_setup);
274 module_param(noirqdebug, bool, 0644);
275 MODULE_PARM_DESC(noirqdebug, "Disable irq lockup detection when true");
276
277 static int __init irqfixup_setup(char *str)
278 {
279         irqfixup = 1;
280         printk(KERN_WARNING "Misrouted IRQ fixup support enabled.\n");
281         printk(KERN_WARNING "This may impact system performance.\n");
282
283         return 1;
284 }
285
286 __setup("irqfixup", irqfixup_setup);
287 module_param(irqfixup, int, 0644);
288 MODULE_PARM_DESC("irqfixup", "0: No fixup, 1: irqfixup mode, 2: irqpoll mode");
289
290 static int __init irqpoll_setup(char *str)
291 {
292         irqfixup = 2;
293         printk(KERN_WARNING "Misrouted IRQ fixup and polling support "
294                                 "enabled\n");
295         printk(KERN_WARNING "This may significantly impact system "
296                                 "performance\n");
297         return 1;
298 }
299
300 __setup("irqpoll", irqpoll_setup);