/* * linux/kernel/irq/chip.c * * Copyright (C) 1992, 1998-2006 Linus Torvalds, Ingo Molnar * Copyright (C) 2005-2006, Thomas Gleixner, Russell King * * This file contains the core interrupt handling code, for irq-chip * based architectures. * * Detailed information is available in Documentation/DocBook/genericirq */ #include <linux/irq.h>#include <linux/module.h>#include <linux/interrupt.h>#include <linux/kernel_stat.h> #include "internals.h" /** * dynamic_irq_init - initialize a dynamically allocated irq * @irq: irq number to initialize */void dynamic_irq_init(unsigned int irq){ struct irq_desc *desc; unsigned long flags; if (irq >= NR_IRQS) { printk(KERN_ERR "Trying to initialize invalid IRQ%d\n", irq); WARN_ON(1); return; } /* Ensure we don't have left over values from a previous use of this irq */ desc = irq_desc + irq; spin_lock_irqsave(&desc->lock, flags); desc->status = IRQ_DISABLED; desc->chip = &no_irq_chip; desc->handle_irq = handle_bad_irq; desc->depth = 1; desc->msi_desc = NULL; desc->handler_data = NULL; desc->chip_data = NULL; desc->action = NULL; desc->irq_count = 0; desc->irqs_unhandled = 0;#ifdef CONFIG_SMP desc->affinity = CPU_MASK_ALL;#endif spin_unlock_irqrestore(&desc->lock, flags);} /** * dynamic_irq_cleanup - cleanup a dynamically allocated irq * @irq: irq number to initialize */void dynamic_irq_cleanup(unsigned int irq){ struct irq_desc *desc; unsigned long flags; if (irq >= NR_IRQS) { printk(KERN_ERR "Trying to cleanup invalid IRQ%d\n", irq); WARN_ON(1); return; } desc = irq_desc + irq; spin_lock_irqsave(&desc->lock, flags); if (desc->action) { spin_unlock_irqrestore(&desc->lock, flags); printk(KERN_ERR "Destroying IRQ%d without calling free_irq\n", irq); WARN_ON(1); return; } desc->msi_desc = NULL; desc->handler_data = NULL; desc->chip_data = NULL; desc->handle_irq = handle_bad_irq; desc->chip = &no_irq_chip; spin_unlock_irqrestore(&desc->lock, flags);} /** * set_irq_chip - set the irq chip for an irq * @irq: irq number * @chip: pointer to irq chip description structure */int set_irq_chip(unsigned int irq, struct irq_chip *chip){ struct irq_desc *desc; unsigned long flags; if (irq >= NR_IRQS) { printk(KERN_ERR "Trying to install chip for IRQ%d\n", irq); WARN_ON(1); return -EINVAL; } if (!chip) chip = &no_irq_chip; desc = irq_desc + irq; spin_lock_irqsave(&desc->lock, flags); irq_chip_set_defaults(chip); desc->chip = chip; spin_unlock_irqrestore(&desc->lock, flags); return 0;}EXPORT_SYMBOL(set_irq_chip); /** * set_irq_type - set the irq type for an irq * @irq: irq number * @type: interrupt type - see include/linux/interrupt.h */int set_irq_type(unsigned int irq, unsigned int type){ struct irq_desc *desc; unsigned long flags; int ret = -ENXIO; if (irq >= NR_IRQS) { printk(KERN_ERR "Trying to set irq type for IRQ%d\n", irq); return -ENODEV; } desc = irq_desc + irq; if (desc->chip->set_type) { spin_lock_irqsave(&desc->lock, flags); ret = desc->chip->set_type(irq, type); spin_unlock_irqrestore(&desc->lock, flags); } return ret;}EXPORT_SYMBOL(set_irq_type); /** * set_irq_data - set irq type data for an irq * @irq: Interrupt number * @data: Pointer to interrupt specific data * * Set the hardware irq controller data for an irq */int set_irq_data(unsigned int irq, void *data){ struct irq_desc *desc; unsigned long flags; if (irq >= NR_IRQS) { printk(KERN_ERR "Trying to install controller data for IRQ%d\n", irq); return -EINVAL; } desc = irq_desc + irq; spin_lock_irqsave(&desc->lock, flags); desc->handler_data = data; spin_unlock_irqrestore(&desc->lock, flags); return 0;}EXPORT_SYMBOL(set_irq_data); /** * set_irq_data - set irq type data for an irq * @irq: Interrupt number * @entry: Pointer to MSI descriptor data * * Set the hardware irq controller data for an irq */int set_irq_msi(unsigned int irq, struct msi_desc *entry){ struct irq_desc *desc; unsigned long flags; if (irq >= NR_IRQS) { printk(KERN_ERR "Trying to install msi data for IRQ%d\n", irq); return -EINVAL; } desc = irq_desc + irq; spin_lock_irqsave(&desc->lock, flags); desc->msi_desc = entry; spin_unlock_irqrestore(&desc->lock, flags); return 0;} /** * set_irq_chip_data - set irq chip data for an irq * @irq: Interrupt number * @data: Pointer to chip specific data * * Set the hardware irq chip data for an irq */int set_irq_chip_data(unsigned int irq, void *data){ struct irq_desc *desc = irq_desc + irq; unsigned long flags; if (irq >= NR_IRQS || !desc->chip) { printk(KERN_ERR "BUG: bad set_irq_chip_data(IRQ#%d)\n", irq); return -EINVAL; } spin_lock_irqsave(&desc->lock, flags); desc->chip_data = data; spin_unlock_irqrestore(&desc->lock, flags); return 0;}EXPORT_SYMBOL(set_irq_chip_data); /* * default enable function */static void default_enable(unsigned int irq){ struct irq_desc *desc = irq_desc + irq; desc->chip->unmask(irq); desc->status &= ~IRQ_MASKED;} /* * default disable function */static void default_disable(unsigned int irq){} /* * default startup function */static unsigned int default_startup(unsigned int irq){ irq_desc[irq].chip->enable(irq); return 0;} /* * Fixup enable/disable function pointers */void irq_chip_set_defaults(struct irq_chip *chip){ if (!chip->enable) chip->enable = default_enable; if (!chip->disable) chip->disable = default_disable; if (!chip->startup) chip->startup = default_startup; if (!chip->shutdown) chip->shutdown = chip->disable; if (!chip->name) chip->name = chip->typename; if (!chip->end) chip->end = dummy_irq_chip.end;} static inline void mask_ack_irq(struct irq_desc *desc, int irq){ if (desc->chip->mask_ack) desc->chip->mask_ack(irq); else { desc->chip->mask(irq); desc->chip->ack(irq); }} /** * handle_simple_irq - Simple and software-decoded IRQs. * @irq: the interrupt number * @desc: the interrupt description structure for this irq * * Simple interrupts are either sent from a demultiplexing interrupt * handler or come from hardware, where no interrupt hardware control * is necessary. * * Note: The caller is expected to handle the ack, clear, mask and * unmask issues if necessary. */void fastcallhandle_simple_irq(unsigned int irq, struct irq_desc *desc){ struct irqaction *action; irqreturn_t action_ret; const unsigned int cpu = smp_processor_id(); spin_lock(&desc->lock); if (unlikely(desc->status & IRQ_INPROGRESS)) goto out_unlock; kstat_cpu(cpu).irqs[irq]++; action = desc->action; if (unlikely(!action || (desc->status & IRQ_DISABLED))) { if (desc->chip->mask) desc->chip->mask(irq); desc->status &= ~(IRQ_REPLAY | IRQ_WAITING); desc->status |= IRQ_PENDING; goto out_unlock; } desc->status &= ~(IRQ_REPLAY | IRQ_WAITING | IRQ_PENDING); desc->status |= IRQ_INPROGRESS; spin_unlock(&desc->lock); action_ret = handle_IRQ_event(irq, action); if (!noirqdebug) note_interrupt(irq, desc, action_ret); spin_lock(&desc->lock); desc->status &= ~IRQ_INPROGRESS;out_unlock: spin_unlock(&desc->lock);} /** * handle_level_irq - Level type irq handler * @irq: the interrupt number * @desc: the interrupt description structure for this irq * * Level type interrupts are active as long as the hardware line has * the active level. This may require to mask the interrupt and unmask * it after the associated handler has acknowledged the device, so the * interrupt line is back to inactive. */void fastcallhandle_level_irq(unsigned int irq, struct irq_desc *desc){ unsigned int cpu = smp_processor_id(); struct irqaction *action; irqreturn_t action_ret; spin_lock(&desc->lock); mask_ack_irq(desc, irq); if (unlikely(desc->status & IRQ_INPROGRESS)) goto out_unlock; desc->status &= ~(IRQ_REPLAY | IRQ_WAITING); kstat_cpu(cpu).irqs[irq]++; /* * If its disabled or no action available * keep it masked and get out of here */ action = desc->action; if (unlikely(!action || (desc->status & IRQ_DISABLED))) { desc->status |= IRQ_PENDING; goto out_unlock; } desc->status |= IRQ_INPROGRESS; desc->status &= ~IRQ_PENDING; spin_unlock(&desc->lock); action_ret = handle_IRQ_event(irq, action); if (!noirqdebug) note_interrupt(irq, desc, action_ret); spin_lock(&desc->lock); desc->status &= ~IRQ_INPROGRESS; if (!(desc->status & IRQ_DISABLED) && desc->chip->unmask) desc->chip->unmask(irq);out_unlock: spin_unlock(&desc->lock);} /** * handle_fasteoi_irq - irq handler for transparent controllers * @irq: the interrupt number * @desc: the interrupt description structure for this irq * * Only a single callback will be issued to the chip: an ->eoi() * call when the interrupt has been serviced. This enables support * for modern forms of interrupt handlers, which handle the flow * details in hardware, transparently. */void fastcallhandle_fasteoi_irq(unsigned int irq, struct irq_desc *desc){ unsigned int cpu = smp_processor_id(); struct irqaction *action; irqreturn_t action_ret; spin_lock(&desc->lock); if (unlikely(desc->status & IRQ_INPROGRESS)) goto out; desc->status &= ~(IRQ_REPLAY | IRQ_WAITING); kstat_cpu(cpu).irqs[irq]++; /* * If its disabled or no action available * then mask it and get out of here: */ action = desc->action; if (unlikely(!action || (desc->status & IRQ_DISABLED))) { desc->status |= IRQ_PENDING; if (desc->chip->mask) desc->chip->mask(irq); goto out; } desc->status |= IRQ_INPROGRESS; desc->status &= ~IRQ_PENDING; spin_unlock(&desc->lock); action_ret = handle_IRQ_event(irq, action); if (!noirqdebug) note_interrupt(irq, desc, action_ret); spin_lock(&desc->lock); desc->status &= ~IRQ_INPROGRESS;out: desc->chip->eoi(irq); spin_unlock(&desc->lock);} /** * handle_edge_irq - edge type IRQ handler * @irq: the interrupt number * @desc: the interrupt description structure for this irq * * Interrupt occures on the falling and/or rising edge of a hardware * signal. The occurence is latched into the irq controller hardware * and must be acked in order to be reenabled. After the ack another * interrupt can happen on the same source even before the first one * is handled by the assosiacted event handler. If this happens it * might be necessary to disable (mask) the interrupt depending on the * controller hardware. This requires to reenable the interrupt inside * of the loop which handles the interrupts which have arrived while * the handler was running. If all pending interrupts are handled, the * loop is left. */void fastcallhandle_edge_irq(unsigned int irq, struct irq_desc *desc){ const unsigned int cpu = smp_processor_id(); spin_lock(&desc->lock); desc->status &= ~(IRQ_REPLAY | IRQ_WAITING); /* * If we're currently running this IRQ, or its disabled, * we shouldn't process the IRQ. Mark it pending, handle * the necessary masking and go out */ if (unlikely((desc->status & (IRQ_INPROGRESS | IRQ_DISABLED)) || !desc->action)) { desc->status |= (IRQ_PENDING | IRQ_MASKED); mask_ack_irq(desc, irq); goto out_unlock; } kstat_cpu(cpu).irqs[irq]++; /* Start handling the irq */ desc->chip->ack(irq); /* Mark the IRQ currently in progress.*/ desc->status |= IRQ_INPROGRESS; do { struct irqaction *action = desc->action; irqreturn_t action_ret; if (unlikely(!action)) { desc->chip->mask(irq); goto out_unlock; } /* * When another irq arrived while we were handling * one, we could have masked the irq. * Renable it, if it was not disabled in meantime. */ if (unlikely((desc->status & (IRQ_PENDING | IRQ_MASKED | IRQ_DISABLED)) == (IRQ_PENDING | IRQ_MASKED))) { desc->chip->unmask(irq); desc->status &= ~IRQ_MASKED; } desc->status &= ~IRQ_PENDING; spin_unlock(&desc->lock); action_ret = handle_IRQ_event(irq, action); if (!noirqdebug) note_interrupt(irq, desc, action_ret); spin_lock(&desc->lock); } while ((desc->status & (IRQ_PENDING | IRQ_DISABLED)) == IRQ_PENDING); Lines 1–500 of 599. 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/* * linux/kernel/irq/chip.c * * Copyright (C) 1992, 1998-2006 Linus Torvalds, Ingo Molnar * Copyright (C) 2005-2006, Thomas Gleixner, Russell King * * This file contains the core interrupt handling code, for irq-chip * based architectures. * * Detailed information is available in Documentation/DocBook/genericirq */ #include <linux/irq.h> #include <linux/module.h> #include <linux/interrupt.h> #include <linux/kernel_stat.h> #include "internals.h" /** * dynamic_irq_init - initialize a dynamically allocated irq * @irq: irq number to initialize */ void dynamic_irq_init(unsigned int irq) { struct irq_desc *desc; unsigned long flags; if (irq >= NR_IRQS) { printk(KERN_ERR "Trying to initialize invalid IRQ%d\n", irq); WARN_ON(1); return; } /* Ensure we don't have left over values from a previous use of this irq */ desc = irq_desc + irq; spin_lock_irqsave(&desc->lock, flags); desc->status = IRQ_DISABLED; desc->chip = &no_irq_chip; desc->handle_irq = handle_bad_irq; desc->depth = 1; desc->msi_desc = NULL; desc->handler_data = NULL; desc->chip_data = NULL; desc->action = NULL; desc->irq_count = 0; desc->irqs_unhandled = 0; #ifdef CONFIG_SMP desc->affinity = CPU_MASK_ALL; #endif spin_unlock_irqrestore(&desc->lock, flags); } /** * dynamic_irq_cleanup - cleanup a dynamically allocated irq * @irq: irq number to initialize */ void dynamic_irq_cleanup(unsigned int irq) { struct irq_desc *desc; unsigned long flags; if (irq >= NR_IRQS) { printk(KERN_ERR "Trying to cleanup invalid IRQ%d\n", irq); WARN_ON(1); return; } desc = irq_desc + irq; spin_lock_irqsave(&desc->lock, flags); if (desc->action) { spin_unlock_irqrestore(&desc->lock, flags); printk(KERN_ERR "Destroying IRQ%d without calling free_irq\n", irq); WARN_ON(1); return; } desc->msi_desc = NULL; desc->handler_data = NULL; desc->chip_data = NULL; desc->handle_irq = handle_bad_irq; desc->chip = &no_irq_chip; spin_unlock_irqrestore(&desc->lock, flags); } /** * set_irq_chip - set the irq chip for an irq * @irq: irq number * @chip: pointer to irq chip description structure */ int set_irq_chip(unsigned int irq, struct irq_chip *chip) { struct irq_desc *desc; unsigned long flags; if (irq >= NR_IRQS) { printk(KERN_ERR "Trying to install chip for IRQ%d\n", irq); WARN_ON(1); return -EINVAL; } if (!chip) chip = &no_irq_chip; desc = irq_desc + irq; spin_lock_irqsave(&desc->lock, flags); irq_chip_set_defaults(chip); desc->chip = chip; spin_unlock_irqrestore(&desc->lock, flags); return 0; } EXPORT_SYMBOL(set_irq_chip); /** * set_irq_type - set the irq type for an irq * @irq: irq number * @type: interrupt type - see include/linux/interrupt.h */ int set_irq_type(unsigned int irq, unsigned int type) { struct irq_desc *desc; unsigned long flags; int ret = -ENXIO; if (irq >= NR_IRQS) { printk(KERN_ERR "Trying to set irq type for IRQ%d\n", irq); return -ENODEV; } desc = irq_desc + irq; if (desc->chip->set_type) { spin_lock_irqsave(&desc->lock, flags); ret = desc->chip->set_type(irq, type); spin_unlock_irqrestore(&desc->lock, flags); } return ret; } EXPORT_SYMBOL(set_irq_type); /** * set_irq_data - set irq type data for an irq * @irq: Interrupt number * @data: Pointer to interrupt specific data * * Set the hardware irq controller data for an irq */ int set_irq_data(unsigned int irq, void *data) { struct irq_desc *desc; unsigned long flags; if (irq >= NR_IRQS) { printk(KERN_ERR "Trying to install controller data for IRQ%d\n", irq); return -EINVAL; } desc = irq_desc + irq; spin_lock_irqsave(&desc->lock, flags); desc->handler_data = data; spin_unlock_irqrestore(&desc->lock, flags); return 0; } EXPORT_SYMBOL(set_irq_data); /** * set_irq_data - set irq type data for an irq * @irq: Interrupt number * @entry: Pointer to MSI descriptor data * * Set the hardware irq controller data for an irq */ int set_irq_msi(unsigned int irq, struct msi_desc *entry) { struct irq_desc *desc; unsigned long flags; if (irq >= NR_IRQS) { printk(KERN_ERR "Trying to install msi data for IRQ%d\n", irq); return -EINVAL; } desc = irq_desc + irq; spin_lock_irqsave(&desc->lock, flags); desc->msi_desc = entry; spin_unlock_irqrestore(&desc->lock, flags); return 0; } /** * set_irq_chip_data - set irq chip data for an irq * @irq: Interrupt number * @data: Pointer to chip specific data * * Set the hardware irq chip data for an irq */ int set_irq_chip_data(unsigned int irq, void *data) { struct irq_desc *desc = irq_desc + irq; unsigned long flags; if (irq >= NR_IRQS || !desc->chip) { printk(KERN_ERR "BUG: bad set_irq_chip_data(IRQ#%d)\n", irq); return -EINVAL; } spin_lock_irqsave(&desc->lock, flags); desc->chip_data = data; spin_unlock_irqrestore(&desc->lock, flags); return 0; } EXPORT_SYMBOL(set_irq_chip_data); /* * default enable function */ static void default_enable(unsigned int irq) { struct irq_desc *desc = irq_desc + irq; desc->chip->unmask(irq); desc->status &= ~IRQ_MASKED; } /* * default disable function */ static void default_disable(unsigned int irq) { } /* * default startup function */ static unsigned int default_startup(unsigned int irq) { irq_desc[irq].chip->enable(irq); return 0; } /* * Fixup enable/disable function pointers */ void irq_chip_set_defaults(struct irq_chip *chip) { if (!chip->enable) chip->enable = default_enable; if (!chip->disable) chip->disable = default_disable; if (!chip->startup) chip->startup = default_startup; if (!chip->shutdown) chip->shutdown = chip->disable; if (!chip->name) chip->name = chip->typename; if (!chip->end) chip->end = dummy_irq_chip.end; } static inline void mask_ack_irq(struct irq_desc *desc, int irq) { if (desc->chip->mask_ack) desc->chip->mask_ack(irq); else { desc->chip->mask(irq); desc->chip->ack(irq); } } /** * handle_simple_irq - Simple and software-decoded IRQs. * @irq: the interrupt number * @desc: the interrupt description structure for this irq * * Simple interrupts are either sent from a demultiplexing interrupt * handler or come from hardware, where no interrupt hardware control * is necessary. * * Note: The caller is expected to handle the ack, clear, mask and * unmask issues if necessary. */ void fastcall handle_simple_irq(unsigned int irq, struct irq_desc *desc) { struct irqaction *action; irqreturn_t action_ret; const unsigned int cpu = smp_processor_id(); spin_lock(&desc->lock); if (unlikely(desc->status & IRQ_INPROGRESS)) goto out_unlock; kstat_cpu(cpu).irqs[irq]++; action = desc->action; if (unlikely(!action || (desc->status & IRQ_DISABLED))) { if (desc->chip->mask) desc->chip->mask(irq); desc->status &= ~(IRQ_REPLAY | IRQ_WAITING); desc->status |= IRQ_PENDING; goto out_unlock; } desc->status &= ~(IRQ_REPLAY | IRQ_WAITING | IRQ_PENDING); desc->status |= IRQ_INPROGRESS; spin_unlock(&desc->lock); action_ret = handle_IRQ_event(irq, action); if (!noirqdebug) note_interrupt(irq, desc, action_ret); spin_lock(&desc->lock); desc->status &= ~IRQ_INPROGRESS; out_unlock: spin_unlock(&desc->lock); } /** * handle_level_irq - Level type irq handler * @irq: the interrupt number * @desc: the interrupt description structure for this irq * * Level type interrupts are active as long as the hardware line has * the active level. This may require to mask the interrupt and unmask * it after the associated handler has acknowledged the device, so the * interrupt line is back to inactive. */ void fastcall handle_level_irq(unsigned int irq, struct irq_desc *desc) { unsigned int cpu = smp_processor_id(); struct irqaction *action; irqreturn_t action_ret; spin_lock(&desc->lock); mask_ack_irq(desc, irq); if (unlikely(desc->status & IRQ_INPROGRESS)) goto out_unlock; desc->status &= ~(IRQ_REPLAY | IRQ_WAITING); kstat_cpu(cpu).irqs[irq]++; /* * If its disabled or no action available * keep it masked and get out of here */ action = desc->action; if (unlikely(!action || (desc->status & IRQ_DISABLED))) { desc->status |= IRQ_PENDING; goto out_unlock; } desc->status |= IRQ_INPROGRESS; desc->status &= ~IRQ_PENDING; spin_unlock(&desc->lock); action_ret = handle_IRQ_event(irq, action); if (!noirqdebug) note_interrupt(irq, desc, action_ret); spin_lock(&desc->lock); desc->status &= ~IRQ_INPROGRESS; if (!(desc->status & IRQ_DISABLED) && desc->chip->unmask) desc->chip->unmask(irq); out_unlock: spin_unlock(&desc->lock); } /** * handle_fasteoi_irq - irq handler for transparent controllers * @irq: the interrupt number * @desc: the interrupt description structure for this irq * * Only a single callback will be issued to the chip: an ->eoi() * call when the interrupt has been serviced. This enables support * for modern forms of interrupt handlers, which handle the flow * details in hardware, transparently. */ void fastcall handle_fasteoi_irq(unsigned int irq, struct irq_desc *desc) { unsigned int cpu = smp_processor_id(); struct irqaction *action; irqreturn_t action_ret; spin_lock(&desc->lock); if (unlikely(desc->status & IRQ_INPROGRESS)) goto out; desc->status &= ~(IRQ_REPLAY | IRQ_WAITING); kstat_cpu(cpu).irqs[irq]++; /* * If its disabled or no action available * then mask it and get out of here: */ action = desc->action; if (unlikely(!action || (desc->status & IRQ_DISABLED))) { desc->status |= IRQ_PENDING; if (desc->chip->mask) desc->chip->mask(irq); goto out; } desc->status |= IRQ_INPROGRESS; desc->status &= ~IRQ_PENDING; spin_unlock(&desc->lock); action_ret = handle_IRQ_event(irq, action); if (!noirqdebug) note_interrupt(irq, desc, action_ret); spin_lock(&desc->lock); desc->status &= ~IRQ_INPROGRESS; out: desc->chip->eoi(irq); spin_unlock(&desc->lock); } /** * handle_edge_irq - edge type IRQ handler * @irq: the interrupt number * @desc: the interrupt description structure for this irq * * Interrupt occures on the falling and/or rising edge of a hardware * signal. The occurence is latched into the irq controller hardware * and must be acked in order to be reenabled. After the ack another * interrupt can happen on the same source even before the first one * is handled by the assosiacted event handler. If this happens it * might be necessary to disable (mask) the interrupt depending on the * controller hardware. This requires to reenable the interrupt inside * of the loop which handles the interrupts which have arrived while * the handler was running. If all pending interrupts are handled, the * loop is left. */ void fastcall handle_edge_irq(unsigned int irq, struct irq_desc *desc) { const unsigned int cpu = smp_processor_id(); spin_lock(&desc->lock); desc->status &= ~(IRQ_REPLAY | IRQ_WAITING); /* * If we're currently running this IRQ, or its disabled, * we shouldn't process the IRQ. Mark it pending, handle * the necessary masking and go out */ if (unlikely((desc->status & (IRQ_INPROGRESS | IRQ_DISABLED)) || !desc->action)) { desc->status |= (IRQ_PENDING | IRQ_MASKED); mask_ack_irq(desc, irq); goto out_unlock; } kstat_cpu(cpu).irqs[irq]++; /* Start handling the irq */ desc->chip->ack(irq); /* Mark the IRQ currently in progress.*/ desc->status |= IRQ_INPROGRESS; do { struct irqaction *action = desc->action; irqreturn_t action_ret; if (unlikely(!action)) { desc->chip->mask(irq); goto out_unlock; } /* * When another irq arrived while we were handling * one, we could have masked the irq. * Renable it, if it was not disabled in meantime. */ if (unlikely((desc->status & (IRQ_PENDING | IRQ_MASKED | IRQ_DISABLED)) == (IRQ_PENDING | IRQ_MASKED))) { desc->chip->unmask(irq); desc->status &= ~IRQ_MASKED; } desc->status &= ~IRQ_PENDING; spin_unlock(&desc->lock); action_ret = handle_IRQ_event(irq, action); if (!noirqdebug) note_interrupt(irq, desc, action_ret); spin_lock(&desc->lock); } while ((desc->status & (IRQ_PENDING | IRQ_DISABLED)) == IRQ_PENDING);