2 * linux/kernel/irq/handle.c
4 * Copyright (C) 1992, 1998-2006 Linus Torvalds, Ingo Molnar
5 * Copyright (C) 2005-2006, Thomas Gleixner, Russell King
7 * This file contains the core interrupt handling code.
9 * Detailed information is available in Documentation/DocBook/genericirq
13 #include <linux/irq.h>
14 #include <linux/random.h>
15 #include <linux/sched.h>
16 #include <linux/interrupt.h>
17 #include <linux/kernel_stat.h>
19 #include <trace/events/irq.h>
21 #include "internals.h"
24 * handle_bad_irq - handle spurious and unhandled irqs
25 * @irq: the interrupt number
26 * @desc: description of the interrupt
28 * Handles spurious and unhandled IRQ's. It also prints a debugmessage.
30 void handle_bad_irq(unsigned int irq
, struct irq_desc
*desc
)
32 print_irq_desc(irq
, desc
);
33 kstat_incr_irqs_this_cpu(irq
, desc
);
38 * Special, empty irq handler:
40 irqreturn_t
no_action(int cpl
, void *dev_id
)
45 static void warn_no_thread(unsigned int irq
, struct irqaction
*action
)
47 if (test_and_set_bit(IRQTF_WARNED
, &action
->thread_flags
))
50 printk(KERN_WARNING
"IRQ %d device %s returned IRQ_WAKE_THREAD "
51 "but no thread function available.", irq
, action
->name
);
55 * handle_IRQ_event - irq action chain handler
56 * @irq: the interrupt number
57 * @action: the interrupt action chain for this irq
59 * Handles the action chain of an irq event
61 irqreturn_t
handle_IRQ_event(unsigned int irq
, struct irqaction
*action
)
63 irqreturn_t ret
, retval
= IRQ_NONE
;
64 unsigned int status
= 0;
67 trace_irq_handler_entry(irq
, action
);
68 ret
= action
->handler(irq
, action
->dev_id
);
69 trace_irq_handler_exit(irq
, action
, ret
);
74 * Set result to handled so the spurious check
80 * Catch drivers which return WAKE_THREAD but
81 * did not set up a thread function
83 if (unlikely(!action
->thread_fn
)) {
84 warn_no_thread(irq
, action
);
89 * Wake up the handler thread for this
90 * action. In case the thread crashed and was
91 * killed we just pretend that we handled the
92 * interrupt. The hardirq handler above has
93 * disabled the device interrupt, so no irq
96 if (likely(!test_bit(IRQTF_DIED
,
97 &action
->thread_flags
))) {
98 set_bit(IRQTF_RUNTHREAD
, &action
->thread_flags
);
99 wake_up_process(action
->thread
);
102 /* Fall through to add to randomness */
104 status
|= action
->flags
;
112 action
= action
->next
;
115 if (status
& IRQF_SAMPLE_RANDOM
)
116 add_interrupt_randomness(irq
);