chip.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/msi.h>
#include <linux/module.h>
#include <linux/interrupt.h>
#include <linux/kernel_stat.h>
#include "internals.h"
static void dynamic_irq_init_x(unsigned int irq, bool keep_chip_data)
{
struct irq_desc *desc;
unsigned long flags;
desc = irq_to_desc(irq);
if (!desc) {
WARN(1, KERN_ERR "Trying to initialize invalid IRQ%d\n", irq);
return;
}
/* Ensure we don't have left over values from a previous use of this irq */
raw_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;
if (!keep_chip_data)
desc->chip_data = NULL;
desc->action = NULL;
desc->irq_count = 0;
desc->irqs_unhandled = 0;
#ifdef CONFIG_SMP
cpumask_setall(desc->affinity);
#ifdef CONFIG_GENERIC_PENDING_IRQ
cpumask_clear(desc->pending_mask);
#endif
#endif
raw_spin_unlock_irqrestore(&desc->lock, flags);
}
/**
* dynamic_irq_init - initialize a dynamically allocated irq
* @irq: irq number to initialize
*/
void dynamic_irq_init(unsigned int irq)
{
dynamic_irq_init_x(irq, false);
}
/**
* dynamic_irq_init_keep_chip_data - initialize a dynamically allocated irq
* @irq: irq number to initialize
*
* does not set irq_to_desc(irq)->chip_data to NULL
*/
void dynamic_irq_init_keep_chip_data(unsigned int irq)
{
dynamic_irq_init_x(irq, true);
}
static void dynamic_irq_cleanup_x(unsigned int irq, bool keep_chip_data)
{
struct irq_desc *desc = irq_to_desc(irq);
unsigned long flags;
if (!desc) {
WARN(1, KERN_ERR "Trying to cleanup invalid IRQ%d\n", irq);
return;
}
raw_spin_lock_irqsave(&desc->lock, flags);
if (desc->action) {
raw_spin_unlock_irqrestore(&desc->lock, flags);
WARN(1, KERN_ERR "Destroying IRQ%d without calling free_irq\n",
irq);
return;
}
desc->msi_desc = NULL;
desc->handler_data = NULL;
if (!keep_chip_data)
desc->chip_data = NULL;
desc->handle_irq = handle_bad_irq;
desc->chip = &no_irq_chip;
desc->name = NULL;
clear_kstat_irqs(desc);
raw_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)
{
dynamic_irq_cleanup_x(irq, false);
}
/**
* dynamic_irq_cleanup_keep_chip_data - cleanup a dynamically allocated irq
* @irq: irq number to initialize
*
* does not set irq_to_desc(irq)->chip_data to NULL
*/
void dynamic_irq_cleanup_keep_chip_data(unsigned int irq)
{
dynamic_irq_cleanup_x(irq, true);
}
/**
* 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 = irq_to_desc(irq);
unsigned long flags;
if (!desc) {
WARN(1, KERN_ERR "Trying to install chip for IRQ%d\n", irq);
return -EINVAL;
}
if (!chip)
chip = &no_irq_chip;
raw_spin_lock_irqsave(&desc->lock, flags);
irq_chip_set_defaults(chip);
desc->chip = chip;
raw_spin_unlock_irqrestore(&desc->lock, flags);
return 0;
}
EXPORT_SYMBOL(set_irq_chip);
/**
* set_irq_type - set the irq trigger type for an irq
* @irq: irq number
* @type: IRQ_TYPE_{LEVEL,EDGE}_* value - see include/linux/irq.h
*/
int set_irq_type(unsigned int irq, unsigned int type)
{
struct irq_desc *desc = irq_to_desc(irq);
unsigned long flags;
int ret = -ENXIO;
if (!desc) {
printk(KERN_ERR "Trying to set irq type for IRQ%d\n", irq);
return -ENODEV;
}
type &= IRQ_TYPE_SENSE_MASK;
if (type == IRQ_TYPE_NONE)
return 0;
raw_spin_lock_irqsave(&desc->lock, flags);
ret = __irq_set_trigger(desc, irq, type);
raw_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 = irq_to_desc(irq);
unsigned long flags;
if (!desc) {
printk(KERN_ERR
"Trying to install controller data for IRQ%d\n", irq);
return -EINVAL;
}
raw_spin_lock_irqsave(&desc->lock, flags);
desc->handler_data = data;
raw_spin_unlock_irqrestore(&desc->lock, flags);
return 0;
}
EXPORT_SYMBOL(set_irq_data);
/**
* set_irq_msi - set MSI descriptor data for an irq
* @irq: Interrupt number
* @entry: Pointer to MSI descriptor data
*
* Set the MSI descriptor entry for an irq
*/
int set_irq_msi(unsigned int irq, struct msi_desc *entry)
{
struct irq_desc *desc = irq_to_desc(irq);
unsigned long flags;
if (!desc) {
printk(KERN_ERR
"Trying to install msi data for IRQ%d\n", irq);
return -EINVAL;
}
raw_spin_lock_irqsave(&desc->lock, flags);
desc->msi_desc = entry;
if (entry)
entry->irq = irq;
raw_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_to_desc(irq);
unsigned long flags;
if (!desc) {
printk(KERN_ERR
"Trying to install chip data for IRQ%d\n", irq);
return -EINVAL;
}
if (!desc->chip) {
printk(KERN_ERR "BUG: bad set_irq_chip_data(IRQ#%d)\n", irq);
return -EINVAL;
}
raw_spin_lock_irqsave(&desc->lock, flags);
desc->chip_data = data;
raw_spin_unlock_irqrestore(&desc->lock, flags);
return 0;
}
EXPORT_SYMBOL(set_irq_chip_data);
/**
* set_irq_nested_thread - Set/Reset the IRQ_NESTED_THREAD flag of an irq
*
* @irq: Interrupt number
* @nest: 0 to clear / 1 to set the IRQ_NESTED_THREAD flag
*
* The IRQ_NESTED_THREAD flag indicates that on
* request_threaded_irq() no separate interrupt thread should be
* created for the irq as the handler are called nested in the
* context of a demultiplexing interrupt handler thread.
*/
void set_irq_nested_thread(unsigned int irq, int nest)
{
struct irq_desc *desc = irq_to_desc(irq);
unsigned long flags;
if (!desc)
return;
raw_spin_lock_irqsave(&desc->lock, flags);
if (nest)
desc->status |= IRQ_NESTED_THREAD;
else
desc->status &= ~IRQ_NESTED_THREAD;
raw_spin_unlock_irqrestore(&desc->lock, flags);
}
EXPORT_SYMBOL_GPL(set_irq_nested_thread);
/*
* default enable function
*/
static void default_enable(unsigned int irq)
{
struct irq_desc *desc = irq_to_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)
{
struct irq_desc *desc = irq_to_desc(irq);
desc->chip->enable(irq);
return 0;
}
/*
* default shutdown function
*/
static void default_shutdown(unsigned int irq)
{
struct irq_desc *desc = irq_to_desc(irq);
desc->chip->mask(irq);
desc->status |= IRQ_MASKED;
}
/*
* 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;
/*
* We use chip->disable, when the user provided its own. When
* we have default_disable set for chip->disable, then we need
* to use default_shutdown, otherwise the irq line is not
* disabled on free_irq():
*/
if (!chip->shutdown)
chip->shutdown = chip->disable != default_disable ?
chip->disable : default_shutdown;
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);
if (desc->chip->ack)
desc->chip->ack(irq);
}
desc->status |= IRQ_MASKED;
}
static inline void mask_irq(struct irq_desc *desc, int irq)
{
if (desc->chip->mask) {
desc->chip->mask(irq);
desc->status |= IRQ_MASKED;
}
}
static inline void unmask_irq(struct irq_desc *desc, int irq)
{
if (desc->chip->unmask) {
desc->chip->unmask(irq);
desc->status &= ~IRQ_MASKED;
}
}
/*
* handle_nested_irq - Handle a nested irq from a irq thread
* @irq: the interrupt number
*
* Handle interrupts which are nested into a threaded interrupt
* handler. The handler function is called inside the calling
* threads context.
*/
void handle_nested_irq(unsigned int irq)
{
struct irq_desc *desc = irq_to_desc(irq);
struct irqaction *action;
irqreturn_t action_ret;
might_sleep();
raw_spin_lock_irq(&desc->lock);
kstat_incr_irqs_this_cpu(irq, desc);
action = desc->action;
if (unlikely(!action || (desc->status & IRQ_DISABLED)))
goto out_unlock;
desc->status |= IRQ_INPROGRESS;
raw_spin_unlock_irq(&desc->lock);
action_ret = action->thread_fn(action->irq, action->dev_id);
if (!noirqdebug)
note_interrupt(irq, desc, action_ret);
raw_spin_lock_irq(&desc->lock);
desc->status &= ~IRQ_INPROGRESS;
out_unlock:
raw_spin_unlock_irq(&desc->lock);
}
EXPORT_SYMBOL_GPL(handle_nested_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
handle_simple_irq(unsigned int irq, struct irq_desc *desc)
{
struct irqaction *action;
irqreturn_t action_ret;
raw_spin_lock(&desc->lock);
if (unlikely(desc->status & IRQ_INPROGRESS))
goto out_unlock;
desc->status &= ~(IRQ_REPLAY | IRQ_WAITING);
kstat_incr_irqs_this_cpu(irq, desc);
action = desc->action;
if (unlikely(!action || (desc->status & IRQ_DISABLED)))
goto out_unlock;
desc->status |= IRQ_INPROGRESS;
raw_spin_unlock(&desc->lock);
action_ret = handle_IRQ_event(irq, action);
if (!noirqdebug)
note_interrupt(irq, desc, action_ret);
raw_spin_lock(&desc->lock);
desc->status &= ~IRQ_INPROGRESS;
out_unlock:
raw_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
handle_level_irq(unsigned int irq, struct irq_desc *desc)
{
struct irqaction *action;
irqreturn_t action_ret;
raw_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_incr_irqs_this_cpu(irq, desc);
/*
* 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)))
goto out_unlock;
desc->status |= IRQ_INPROGRESS;
raw_spin_unlock(&desc->lock);
action_ret = handle_IRQ_event(irq, action);
if (!noirqdebug)
note_interrupt(irq, desc, action_ret);
raw_spin_lock(&desc->lock);
desc->status &= ~IRQ_INPROGRESS;
if (!(desc->status & (IRQ_DISABLED | IRQ_ONESHOT)))
unmask_irq(desc, irq);
out_unlock:
raw_spin_unlock(&desc->lock);
}
EXPORT_SYMBOL_GPL(handle_level_irq);
/**
* 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
handle_fasteoi_irq(unsigned int irq, struct irq_desc *desc)
{
struct irqaction *action;
irqreturn_t action_ret;
raw_spin_lock(&desc->lock);
if (unlikely(desc->status & IRQ_INPROGRESS))
goto out;
desc->status &= ~(IRQ_REPLAY | IRQ_WAITING);
kstat_incr_irqs_this_cpu(irq, desc);
/*
* 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;
mask_irq(desc, irq);
goto out;
}
desc->status |= IRQ_INPROGRESS;
desc->status &= ~IRQ_PENDING;
raw_spin_unlock(&desc->lock);
action_ret = handle_IRQ_event(irq, action);
if (!noirqdebug)
note_interrupt(irq, desc, action_ret);
raw_spin_lock(&desc->lock);
desc->status &= ~IRQ_INPROGRESS;
out:
desc->chip->eoi(irq);
raw_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 associated 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
handle_edge_irq(unsigned int irq, struct irq_desc *desc)
{
raw_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_incr_irqs_this_cpu(irq, desc);
/* Start handling the irq */
if (desc->chip->ack)
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)) {
mask_irq(desc, 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))) {
unmask_irq(desc, irq);
}
desc->status &= ~IRQ_PENDING;
raw_spin_unlock(&desc->lock);
action_ret = handle_IRQ_event(irq, action);
if (!noirqdebug)
note_interrupt(irq, desc, action_ret);
raw_spin_lock(&desc->lock);
} while ((desc->status & (IRQ_PENDING | IRQ_DISABLED)) == IRQ_PENDING);
desc->status &= ~IRQ_INPROGRESS;
out_unlock:
raw_spin_unlock(&desc->lock);
}
/**
* handle_percpu_irq - Per CPU local irq handler
* @irq: the interrupt number
* @desc: the interrupt description structure for this irq
*
* Per CPU interrupts on SMP machines without locking requirements
*/
void
handle_percpu_irq(unsigned int irq, struct irq_desc *desc)
{
irqreturn_t action_ret;
kstat_incr_irqs_this_cpu(irq, desc);
if (desc->chip->ack)
desc->chip->ack(irq);
action_ret = handle_IRQ_event(irq, desc->action);
if (!noirqdebug)
note_interrupt(irq, desc, action_ret);
if (desc->chip->eoi)
desc->chip->eoi(irq);
}
void
__set_irq_handler(unsigned int irq, irq_flow_handler_t handle, int is_chained,
const char *name)
{
struct irq_desc *desc = irq_to_desc(irq);
unsigned long flags;
if (!desc) {
printk(KERN_ERR
"Trying to install type control for IRQ%d\n", irq);
return;
}
if (!handle)
handle = handle_bad_irq;
else 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;
}
chip_bus_lock(irq, desc);
raw_spin_lock_irqsave(&desc->lock, flags);
/* Uninstall? */
if (handle == handle_bad_irq) {
if (desc->chip != &no_irq_chip)
mask_ack_irq(desc, irq);
desc->status |= IRQ_DISABLED;
desc->depth = 1;
}
desc->handle_irq = handle;
desc->name = name;
if (handle != handle_bad_irq && is_chained) {
desc->status &= ~IRQ_DISABLED;
desc->status |= IRQ_NOREQUEST | IRQ_NOPROBE;
desc->depth = 0;
desc->chip->startup(irq);
}
raw_spin_unlock_irqrestore(&desc->lock, flags);
chip_bus_sync_unlock(irq, desc);
}
EXPORT_SYMBOL_GPL(__set_irq_handler);
void
set_irq_chip_and_handler(unsigned int irq, struct irq_chip *chip,
irq_flow_handler_t handle)
{
set_irq_chip(irq, chip);
__set_irq_handler(irq, handle, 0, NULL);
}
void
set_irq_chip_and_handler_name(unsigned int irq, struct irq_chip *chip,
irq_flow_handler_t handle, const char *name)
{
set_irq_chip(irq, chip);
__set_irq_handler(irq, handle, 0, name);
}
void set_irq_noprobe(unsigned int irq)
{
struct irq_desc *desc = irq_to_desc(irq);
unsigned long flags;
if (!desc) {
printk(KERN_ERR "Trying to mark IRQ%d non-probeable\n", irq);
return;
}
raw_spin_lock_irqsave(&desc->lock, flags);
desc->status |= IRQ_NOPROBE;
raw_spin_unlock_irqrestore(&desc->lock, flags);
}
void set_irq_probe(unsigned int irq)
{
struct irq_desc *desc = irq_to_desc(irq);
unsigned long flags;
if (!desc) {
printk(KERN_ERR "Trying to mark IRQ%d probeable\n", irq);
return;
}
raw_spin_lock_irqsave(&desc->lock, flags);
desc->status &= ~IRQ_NOPROBE;
raw_spin_unlock_irqrestore(&desc->lock, flags);
}