blob: 14dd5761e8c96e1508c72499e12c93edeb45a7ab [file] [log] [blame]
Thomas Gleixnera4633ad2006-06-29 02:24:48 -07001/*
2 * linux/kernel/irq/resend.c
3 *
4 * Copyright (C) 1992, 1998-2006 Linus Torvalds, Ingo Molnar
5 * Copyright (C) 2005-2006, Thomas Gleixner
6 *
7 * This file contains the IRQ-resend code
8 *
9 * If the interrupt is waiting to be processed, we try to re-run it.
10 * We can't directly run it from here since the caller might be in an
11 * interrupt-protected region. Not all irq controller chips can
12 * retrigger interrupts at the hardware level, so in those cases
13 * we allow the resending of IRQs via a tasklet.
14 */
15
16#include <linux/irq.h>
17#include <linux/module.h>
18#include <linux/random.h>
19#include <linux/interrupt.h>
20
21#include "internals.h"
22
23#ifdef CONFIG_HARDIRQS_SW_RESEND
24
25/* Bitmap to handle software resend of interrupts: */
Thomas Gleixnerc1ee6262011-02-17 17:45:15 +010026static DECLARE_BITMAP(irqs_resend, IRQ_BITMAP_BITS);
Thomas Gleixnera4633ad2006-06-29 02:24:48 -070027
28/*
29 * Run software resends of IRQ's
30 */
31static void resend_irqs(unsigned long arg)
32{
33 struct irq_desc *desc;
34 int irq;
35
Yinghai Lu85c0f902008-08-19 20:49:47 -070036 while (!bitmap_empty(irqs_resend, nr_irqs)) {
37 irq = find_first_bit(irqs_resend, nr_irqs);
Thomas Gleixnera4633ad2006-06-29 02:24:48 -070038 clear_bit(irq, irqs_resend);
Yinghai Lu08678b02008-08-19 20:50:05 -070039 desc = irq_to_desc(irq);
Thomas Gleixner6a6de9e2006-06-29 02:24:51 -070040 local_irq_disable();
Frederik Deweerdte317c8c2006-10-06 18:58:24 +000041 desc->handle_irq(irq, desc);
Thomas Gleixner6a6de9e2006-06-29 02:24:51 -070042 local_irq_enable();
Thomas Gleixnera4633ad2006-06-29 02:24:48 -070043 }
44}
45
46/* Tasklet to handle resend: */
47static DECLARE_TASKLET(resend_tasklet, resend_irqs, 0);
48
49#endif
50
51/*
52 * IRQ resend
53 *
54 * Is called with interrupts disabled and desc->lock held.
55 */
56void check_irq_resend(struct irq_desc *desc, unsigned int irq)
57{
Thomas Gleixnera4633ad2006-06-29 02:24:48 -070058 /*
Thomas Gleixner24642862007-08-12 15:46:35 +000059 * We do not resend level type interrupts. Level type
60 * interrupts are resent by hardware when they are still
61 * active.
62 */
Thomas Gleixner876dbd42011-02-08 17:28:12 +010063 if (irq_settings_is_level(desc))
Thomas Gleixner87923472011-02-03 12:27:44 +010064 return;
Thomas Gleixner163ef302011-02-08 11:39:15 +010065 if (desc->istate & IRQS_REPLAY)
66 return;
Thomas Gleixner2a0d6fb2011-02-08 12:17:57 +010067 if (desc->istate & IRQS_PENDING) {
Thomas Gleixner2a0d6fb2011-02-08 12:17:57 +010068 desc->istate &= ~IRQS_PENDING;
Thomas Gleixner163ef302011-02-08 11:39:15 +010069 desc->istate |= IRQS_REPLAY;
Thomas Gleixnera4633ad2006-06-29 02:24:48 -070070
Thomas Gleixner21e2b8c2010-09-27 12:45:53 +000071 if (!desc->irq_data.chip->irq_retrigger ||
72 !desc->irq_data.chip->irq_retrigger(&desc->irq_data)) {
Thomas Gleixnera4633ad2006-06-29 02:24:48 -070073#ifdef CONFIG_HARDIRQS_SW_RESEND
74 /* Set it pending and activate the softirq: */
75 set_bit(irq, irqs_resend);
76 tasklet_schedule(&resend_tasklet);
77#endif
78 }
79 }
80}