Messages in this thread Patch in this message | | | Date | Wed, 17 May 2006 02:16:56 +0200 | From | Ingo Molnar <> | Subject | [patch 22/50] genirq: add irq-chip support |
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From: Thomas Gleixner <tglx@linutronix.de>
enable platforms to use the irq-chip and irq-flow abstractions: allow setting of the chip, the type and provide highlevel handlers for common irq-flows.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Ingo Molnar <mingo@elte.hu> --- include/linux/irq.h | 14 + kernel/irq/Makefile | 2 kernel/irq/chip.c | 370 ++++++++++++++++++++++++++++++++++++++++++++++++++++ 3 files changed, 385 insertions(+), 1 deletion(-)
Index: linux-genirq.q/include/linux/irq.h =================================================================== --- linux-genirq.q.orig/include/linux/irq.h +++ linux-genirq.q/include/linux/irq.h @@ -308,6 +308,20 @@ extern int can_request_irq(unsigned int /* Dummy irq-chip implementation: */ extern struct irq_chip no_irq_chip; +/* Set/get chip/data for an IRQ: */ + +extern int set_irq_chip(unsigned int irq, struct irq_chip *chip); +extern int set_irq_data(unsigned int irq, void *data); +extern int set_irq_chip_data(unsigned int irq, void *data); +extern int set_irq_type(unsigned int irq, unsigned int type); + +#define get_irq_chip(irq) (irq_desc[irq].handler) +#define get_irq_chip_data(irq) (irq_desc[irq].chip_data) +#define get_irq_data(irq) (irq_desc[irq].handler_data) + +/* Set default functions for irq_chip structures: */ +extern void irq_chip_set_defaults(struct irq_chip *chip); + #endif /* CONFIG_GENERIC_HARDIRQS */ #endif /* !CONFIG_S390 */ Index: linux-genirq.q/kernel/irq/Makefile =================================================================== --- linux-genirq.q.orig/kernel/irq/Makefile +++ linux-genirq.q/kernel/irq/Makefile @@ -1,5 +1,5 @@ -obj-y := handle.o manage.o spurious.o resend.o +obj-y := handle.o manage.o spurious.o resend.o chip.o obj-$(CONFIG_GENERIC_IRQ_PROBE) += autoprobe.o obj-$(CONFIG_PROC_FS) += proc.o obj-$(CONFIG_GENERIC_PENDING_IRQ) += migration.o Index: linux-genirq.q/kernel/irq/chip.c =================================================================== --- /dev/null +++ linux-genirq.q/kernel/irq/chip.c @@ -0,0 +1,370 @@ +/* + * 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" + +/** + * 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->handler = 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->handler->set_type) { + spin_lock_irqsave(&desc->lock, flags); + ret = desc->handler->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_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->handler) { + 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->handler->unmask(irq); + desc->status &= ~IRQ_MASKED; +} + +/* + * default disable function + */ +static void default_disable(unsigned int irq) +{ + irq_desc[irq].handler->mask(irq); +} + +/* + * default startup function + */ +static unsigned int default_startup(unsigned int irq) +{ + irq_desc[irq].handler->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; +} + +static inline void mask_ack_irq(struct irq_desc *desc, int irq) +{ + if (desc->handler->mask_ack) + desc->handler->mask_ack(irq); + else { + desc->handler->mask(irq); + desc->handler->ack(irq); + } +} + +/** + * handle_simple_irq - Simple and software-decoded IRQs. + * @irq: the interrupt number + * @desc: the interrupt description structure for this irq + * @regs: pointer to a register structure + * + * 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. + * + * Must be called with the irq_desc->lock held + */ +void +handle_simple_irq(unsigned int irq, struct irq_desc *desc, struct pt_regs *regs) +{ + struct irqaction *action; + irqreturn_t action_ret; + const unsigned int cpu = smp_processor_id(); + + kstat_cpu(cpu).irqs[irq]++; + + desc->status &= ~(IRQ_REPLAY | IRQ_WAITING); + + action = desc->action; + if (unlikely(!action || desc->depth)) + return; + + desc->status |= IRQ_INPROGRESS; + spin_unlock(&desc->lock); + action_ret = handle_IRQ_event(irq, regs, action); + if (!noirqdebug) + note_interrupt(irq, desc, action_ret, regs); + spin_lock(&desc->lock); + desc->status &= ~IRQ_INPROGRESS; +} + +/** + * handle_level_irq - Level type irq handler + * @irq: the interrupt number + * @desc: the interrupt description structure for this irq + * @regs: pointer to a register structure + * + * 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. + * + * Must be called with the irq_desc->lock held + */ +void +handle_level_irq(unsigned int irq, struct irq_desc *desc, struct pt_regs *regs) +{ + struct irqaction *action; + irqreturn_t action_ret; + const unsigned int cpu = smp_processor_id(); + + kstat_cpu(cpu).irqs[irq]++; + + desc->status &= ~(IRQ_REPLAY | IRQ_WAITING); + + mask_ack_irq(desc, irq); + + /* + * If its disabled or no action available + * keep it masked and get out of here + */ + action = desc->action; + if (unlikely(!action || desc->depth)) + goto out; + + desc->status |= IRQ_INPROGRESS; + spin_unlock(&desc->lock); + action_ret = handle_IRQ_event(irq, regs, action); + if (!noirqdebug) + note_interrupt(irq, desc, action_ret, regs); + spin_lock(&desc->lock); + + desc->status &= ~IRQ_INPROGRESS; +out: + if (!desc->depth && desc->handler->unmask) + desc->handler->unmask(irq); +} + +/** + * handle_edge_irq - edge type IRQ handler + * @irq: the interrupt number + * @desc: the interrupt description structure for this irq + * @regs: pointer to a register structure + * + * 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 and depending on the hardware controller some final + * ack might be necessary. + * + * Must be called with the irq_desc->lock held + */ +void +handle_edge_irq(unsigned int irq, struct irq_desc *desc, struct pt_regs *regs) +{ + const unsigned int cpu = smp_processor_id(); + + kstat_cpu(cpu).irqs[irq]++; + + 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) || desc->depth || + !desc->action)) { + desc->status |= (IRQ_PENDING | IRQ_MASKED); + mask_ack_irq(desc, irq); + return; + } + + /* Start handling the irq */ + desc->handler->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->handler->mask(irq); + return; + } + + /* + * 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_PENDING | IRQ_MASKED)) && !desc->depth)) { + desc->handler->unmask(irq); + desc->status &= ~IRQ_MASKED; + } + + desc->status &= ~IRQ_PENDING; + spin_unlock(&desc->lock); + action_ret = handle_IRQ_event(irq, regs, action); + if (!noirqdebug) + note_interrupt(irq, desc, action_ret, regs); + spin_lock(&desc->lock); + + } while ((desc->status & IRQ_PENDING) && !desc->depth); + + desc->status &= ~IRQ_INPROGRESS; +} + +#ifdef CONFIG_SMP +/** + * handle_percpu_IRQ - Per CPU local irq handler + * @irq: the interrupt number + * @desc: the interrupt description structure for this irq + * @regs: pointer to a register structure + * + * Per CPU interrupts on SMP machines without locking requirements + */ +void +handle_percpu_irq(unsigned int irq, struct irq_desc *desc, struct pt_regs *regs) +{ + irqreturn_t action_ret; + + kstat_this_cpu.irqs[irq]++; + + if (desc->handler->ack) + desc->handler->ack(irq); + + action_ret = handle_IRQ_event(irq, regs, desc->action); + if (!noirqdebug) + note_interrupt(irq, desc, action_ret, regs); + + if (desc->handler->end) + desc->handler->end(irq); +} +#endif /* CONFIG_SMP */ - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
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