/* * linux/kernel/irq/resend.c * * Copyright (C) 1992, 1998-2006 Linus Torvalds, Ingo Molnar * Copyright (C) 2005-2006, Thomas Gleixner * * This file contains the IRQ-resend code * * If the interrupt is waiting to be processed, we try to re-run it. * We can't directly run it from here since the caller might be in an * interrupt-protected region. Not all irq controller chips can * retrigger interrupts at the hardware level, so in those cases * we allow the resending of IRQs via a tasklet. */ #include #include #include #include #include "internals.h" #ifdef CONFIG_HARDIRQS_SW_RESEND /* Bitmap to handle software resend of interrupts: */ static DECLARE_BITMAP(irqs_resend, IRQ_BITMAP_BITS); /* * Run software resends of IRQ's */ static void resend_irqs(unsigned long arg) { struct irq_desc *desc; int irq; while (!bitmap_empty(irqs_resend, nr_irqs)) { irq = find_first_bit(irqs_resend, nr_irqs); clear_bit(irq, irqs_resend); desc = irq_to_desc(irq); local_irq_disable(); desc->handle_irq(desc); local_irq_enable(); } } /* Tasklet to handle resend: */ static DECLARE_TASKLET(resend_tasklet, resend_irqs, 0); #endif /* * IRQ resend * * Is called with interrupts disabled and desc->lock held. */ void check_irq_resend(struct irq_desc *desc) { /* * We do not resend level type interrupts. Level type * interrupts are resent by hardware when they are still * active. Clear the pending bit so suspend/resume does not * get confused. */ if (irq_settings_is_level(desc)) { desc->istate &= ~IRQS_PENDING; return; } if (desc->istate & IRQS_REPLAY) return; if (desc->istate & IRQS_PENDING) { desc->istate &= ~IRQS_PENDING; desc->istate |= IRQS_REPLAY; if (!desc->irq_data.chip->irq_retrigger || !desc->irq_data.chip->irq_retrigger(&desc->irq_data)) { #ifdef CONFIG_HARDIRQS_SW_RESEND unsigned int irq = irq_desc_get_irq(desc); /* * If the interrupt is running in the thread * context of the parent irq we need to be * careful, because we cannot trigger it * directly. */ if (irq_settings_is_nested_thread(desc)) { /* * If the parent_irq is valid, we * retrigger the parent, otherwise we * do nothing. */ if (!desc->parent_irq) return; irq = desc->parent_irq; } /* Set it pending and activate the softirq: */ set_bit(irq, irqs_resend); tasklet_schedule(&resend_tasklet); #endif } } } >
AgeCommit message (Expand)AuthorFilesLines