kernel-ark/kernel/irq/chip.c
Benjamin Herrenschmidt 5a43a066b1 [PATCH] genirq: Allow fasteoi handler to retrigger disabled interrupts
Make the fasteoi handler mark disabled interrupts as pending if they
happen anyway. This allow implementation of a delayed disable scheme
with the fasteoi handler.

Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Acked-by: Thomas Gleixner <tglx@linutronix.de>
Acked-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Paul Mackerras <paulus@samba.org>
2006-07-03 19:54:59 +10:00

538 lines
13 KiB
C

/*
* 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->chip = chip;
/*
* For compatibility only:
*/
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_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)
{
struct irq_desc *desc = irq_desc + irq;
if (!(desc->status & IRQ_DELAYED_DISABLE))
irq_desc[irq].chip->mask(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;
}
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
* @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.
*/
void fastcall
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();
spin_lock(&desc->lock);
if (unlikely(desc->status & IRQ_INPROGRESS))
goto out_unlock;
desc->status &= ~(IRQ_REPLAY | IRQ_WAITING);
kstat_cpu(cpu).irqs[irq]++;
action = desc->action;
if (unlikely(!action || (desc->status & IRQ_DISABLED)))
goto out_unlock;
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_unlock:
spin_unlock(&desc->lock);
}
/**
* 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.
*/
void fastcall
handle_level_irq(unsigned int irq, struct irq_desc *desc, struct pt_regs *regs)
{
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;
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;
}
desc->status |= IRQ_INPROGRESS;
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);
desc->status &= ~IRQ_INPROGRESS;
out:
if (!(desc->status & IRQ_DISABLED) && desc->chip->unmask)
desc->chip->unmask(irq);
spin_unlock(&desc->lock);
}
/**
* handle_fasteoi_irq - irq handler for transparent controllers
* @irq: the interrupt number
* @desc: the interrupt description structure for this irq
* @regs: pointer to a register structure
*
* 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,
struct pt_regs *regs)
{
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
* keep it masked and get out of here
*/
action = desc->action;
if (unlikely(!action || (desc->status & IRQ_DISABLED))) {
desc->status |= IRQ_PENDING;
goto out;
}
desc->status |= IRQ_INPROGRESS;
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);
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
* @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.
*/
void fastcall
handle_edge_irq(unsigned int irq, struct irq_desc *desc, struct pt_regs *regs)
{
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, regs, action);
if (!noirqdebug)
note_interrupt(irq, desc, action_ret, regs);
spin_lock(&desc->lock);
} while ((desc->status & (IRQ_PENDING | IRQ_DISABLED)) == IRQ_PENDING);
desc->status &= ~IRQ_INPROGRESS;
out_unlock:
spin_unlock(&desc->lock);
}
#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 fastcall
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->chip->ack)
desc->chip->ack(irq);
action_ret = handle_IRQ_event(irq, regs, desc->action);
if (!noirqdebug)
note_interrupt(irq, desc, action_ret, regs);
if (desc->chip->eoi)
desc->chip->eoi(irq);
}
#endif /* CONFIG_SMP */
void
__set_irq_handler(unsigned int irq,
void fastcall (*handle)(unsigned int, irq_desc_t *,
struct pt_regs *),
int is_chained)
{
struct irq_desc *desc;
unsigned long flags;
if (irq >= NR_IRQS) {
printk(KERN_ERR
"Trying to install type control for IRQ%d\n", irq);
return;
}
desc = irq_desc + irq;
if (!handle)
handle = handle_bad_irq;
if (desc->chip == &no_irq_chip) {
printk(KERN_WARNING "Trying to install %sinterrupt handler "
"for IRQ%d\n", is_chained ? "chained " : " ", irq);
/*
* Some ARM implementations install a handler for really dumb
* interrupt hardware without setting an irq_chip. This worked
* with the ARM no_irq_chip but the check in setup_irq would
* prevent us to setup the interrupt at all. Switch it to
* dummy_irq_chip for easy transition.
*/
desc->chip = &dummy_irq_chip;
}
spin_lock_irqsave(&desc->lock, flags);
/* Uninstall? */
if (handle == handle_bad_irq) {
if (desc->chip != &no_irq_chip) {
desc->chip->mask(irq);
desc->chip->ack(irq);
}
desc->status |= IRQ_DISABLED;
desc->depth = 1;
}
desc->handle_irq = handle;
if (handle != handle_bad_irq && is_chained) {
desc->status &= ~IRQ_DISABLED;
desc->status |= IRQ_NOREQUEST | IRQ_NOPROBE;
desc->depth = 0;
desc->chip->unmask(irq);
}
spin_unlock_irqrestore(&desc->lock, flags);
}
void
set_irq_chip_and_handler(unsigned int irq, struct irq_chip *chip,
void fastcall (*handle)(unsigned int,
struct irq_desc *,
struct pt_regs *))
{
set_irq_chip(irq, chip);
__set_irq_handler(irq, handle, 0);
}
/*
* Get a descriptive string for the highlevel handler, for
* /proc/interrupts output:
*/
const char *
handle_irq_name(void fastcall (*handle)(unsigned int, struct irq_desc *,
struct pt_regs *))
{
if (handle == handle_level_irq)
return "level ";
if (handle == handle_fasteoi_irq)
return "fasteoi";
if (handle == handle_edge_irq)
return "edge ";
if (handle == handle_simple_irq)
return "simple ";
#ifdef CONFIG_SMP
if (handle == handle_percpu_irq)
return "percpu ";
#endif
if (handle == handle_bad_irq)
return "bad ";
return NULL;
}