Thomas Gleixner | a4633adc | 2006-06-29 02:24:48 -0700 | [diff] [blame] | 1 | /* |
| 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: */ |
| 26 | static DECLARE_BITMAP(irqs_resend, NR_IRQS); |
| 27 | |
| 28 | /* |
| 29 | * Run software resends of IRQ's |
| 30 | */ |
| 31 | static void resend_irqs(unsigned long arg) |
| 32 | { |
| 33 | struct irq_desc *desc; |
| 34 | int irq; |
| 35 | |
| 36 | while (!bitmap_empty(irqs_resend, NR_IRQS)) { |
| 37 | irq = find_first_bit(irqs_resend, NR_IRQS); |
| 38 | clear_bit(irq, irqs_resend); |
| 39 | desc = irq_desc + irq; |
Thomas Gleixner | 6a6de9e | 2006-06-29 02:24:51 -0700 | [diff] [blame] | 40 | local_irq_disable(); |
Frederik Deweerdt | e317c8c | 2006-10-06 18:58:24 +0000 | [diff] [blame] | 41 | desc->handle_irq(irq, desc); |
Thomas Gleixner | 6a6de9e | 2006-06-29 02:24:51 -0700 | [diff] [blame] | 42 | local_irq_enable(); |
Thomas Gleixner | a4633adc | 2006-06-29 02:24:48 -0700 | [diff] [blame] | 43 | } |
| 44 | } |
| 45 | |
| 46 | /* Tasklet to handle resend: */ |
| 47 | static 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 | */ |
| 56 | void check_irq_resend(struct irq_desc *desc, unsigned int irq) |
| 57 | { |
| 58 | unsigned int status = desc->status; |
| 59 | |
| 60 | /* |
| 61 | * Make sure the interrupt is enabled, before resending it: |
| 62 | */ |
| 63 | desc->chip->enable(irq); |
| 64 | |
Thomas Gleixner | 2464286 | 2007-08-12 15:46:35 +0000 | [diff] [blame] | 65 | /* |
| 66 | * We do not resend level type interrupts. Level type |
| 67 | * interrupts are resent by hardware when they are still |
| 68 | * active. |
| 69 | */ |
| 70 | if ((status & (IRQ_LEVEL | IRQ_PENDING | IRQ_REPLAY)) == IRQ_PENDING) { |
Imre Deak | e1ed7ac | 2006-09-16 12:15:35 -0700 | [diff] [blame] | 71 | desc->status = (status & ~IRQ_PENDING) | IRQ_REPLAY; |
Thomas Gleixner | a4633adc | 2006-06-29 02:24:48 -0700 | [diff] [blame] | 72 | |
| 73 | if (!desc->chip || !desc->chip->retrigger || |
| 74 | !desc->chip->retrigger(irq)) { |
| 75 | #ifdef CONFIG_HARDIRQS_SW_RESEND |
| 76 | /* Set it pending and activate the softirq: */ |
| 77 | set_bit(irq, irqs_resend); |
| 78 | tasklet_schedule(&resend_tasklet); |
| 79 | #endif |
| 80 | } |
| 81 | } |
| 82 | } |