linux/kernel/irq/chip.c

777 lines
19 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/msi.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 = 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->irq_data.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->irq_data.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->irq_data.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->irq_data.chip) {
printk(KERN_ERR "BUG: bad set_irq_chip_data(IRQ#%d)\n", irq);
return -EINVAL;
}
raw_spin_lock_irqsave(&desc->lock, flags);
desc->irq_data.chip_data = data;
raw_spin_unlock_irqrestore(&desc->lock, flags);
return 0;
}
EXPORT_SYMBOL(set_irq_chip_data);
struct irq_data *irq_get_irq_data(unsigned int irq)
{
struct irq_desc *desc = irq_to_desc(irq);
return desc ? &desc->irq_data : NULL;
}
EXPORT_SYMBOL_GPL(irq_get_irq_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(struct irq_data *data)
{
struct irq_desc *desc = irq_data_to_desc(data);
desc->irq_data.chip->irq_unmask(&desc->irq_data);
desc->status &= ~IRQ_MASKED;
}
/*
* default disable function
*/
static void default_disable(struct irq_data *data)
{
}
/*
* default startup function
*/
static unsigned int default_startup(struct irq_data *data)
{
struct irq_desc *desc = irq_data_to_desc(data);
desc->irq_data.chip->irq_enable(data);
return 0;
}
/*
* default shutdown function
*/
static void default_shutdown(struct irq_data *data)
{
struct irq_desc *desc = irq_data_to_desc(data);
desc->irq_data.chip->irq_mask(&desc->irq_data);
desc->status |= IRQ_MASKED;
}
#ifndef CONFIG_GENERIC_HARDIRQS_NO_DEPRECATED
/* Temporary migration helpers */
static void compat_irq_mask(struct irq_data *data)
{
data->chip->mask(data->irq);
}
static void compat_irq_unmask(struct irq_data *data)
{
data->chip->unmask(data->irq);
}
static void compat_irq_ack(struct irq_data *data)
{
data->chip->ack(data->irq);
}
static void compat_irq_mask_ack(struct irq_data *data)
{
data->chip->mask_ack(data->irq);
}
static void compat_irq_eoi(struct irq_data *data)
{
data->chip->eoi(data->irq);
}
static void compat_irq_enable(struct irq_data *data)
{
data->chip->enable(data->irq);
}
static void compat_irq_disable(struct irq_data *data)
{
data->chip->disable(data->irq);
}
static void compat_irq_shutdown(struct irq_data *data)
{
data->chip->shutdown(data->irq);
}
static unsigned int compat_irq_startup(struct irq_data *data)
{
return data->chip->startup(data->irq);
}
static int compat_irq_set_affinity(struct irq_data *data,
const struct cpumask *dest, bool force)
{
return data->chip->set_affinity(data->irq, dest);
}
static int compat_irq_set_type(struct irq_data *data, unsigned int type)
{
return data->chip->set_type(data->irq, type);
}
static int compat_irq_set_wake(struct irq_data *data, unsigned int on)
{
return data->chip->set_wake(data->irq, on);
}
static int compat_irq_retrigger(struct irq_data *data)
{
return data->chip->retrigger(data->irq);
}
static void compat_bus_lock(struct irq_data *data)
{
data->chip->bus_lock(data->irq);
}
static void compat_bus_sync_unlock(struct irq_data *data)
{
data->chip->bus_sync_unlock(data->irq);
}
#endif
/*
* Fixup enable/disable function pointers
*/
void irq_chip_set_defaults(struct irq_chip *chip)
{
#ifndef CONFIG_GENERIC_HARDIRQS_NO_DEPRECATED
/*
* Compat fixup functions need to be before we set the
* defaults for enable/disable/startup/shutdown
*/
if (chip->enable)
chip->irq_enable = compat_irq_enable;
if (chip->disable)
chip->irq_disable = compat_irq_disable;
if (chip->shutdown)
chip->irq_shutdown = compat_irq_shutdown;
if (chip->startup)
chip->irq_startup = compat_irq_startup;
#endif
/*
* The real defaults
*/
if (!chip->irq_enable)
chip->irq_enable = default_enable;
if (!chip->irq_disable)
chip->irq_disable = default_disable;
if (!chip->irq_startup)
chip->irq_startup = default_startup;
/*
* We use chip->irq_disable, when the user provided its own. When
* we have default_disable set for chip->irq_disable, then we need
* to use default_shutdown, otherwise the irq line is not
* disabled on free_irq():
*/
if (!chip->irq_shutdown)
chip->irq_shutdown = chip->irq_disable != default_disable ?
chip->irq_disable : default_shutdown;
#ifndef CONFIG_GENERIC_HARDIRQS_NO_DEPRECATED
if (!chip->end)
chip->end = dummy_irq_chip.end;
/*
* Now fix up the remaining compat handlers
*/
if (chip->bus_lock)
chip->irq_bus_lock = compat_bus_lock;
if (chip->bus_sync_unlock)
chip->irq_bus_sync_unlock = compat_bus_sync_unlock;
if (chip->mask)
chip->irq_mask = compat_irq_mask;
if (chip->unmask)
chip->irq_unmask = compat_irq_unmask;
if (chip->ack)
chip->irq_ack = compat_irq_ack;
if (chip->mask_ack)
chip->irq_mask_ack = compat_irq_mask_ack;
if (chip->eoi)
chip->irq_eoi = compat_irq_eoi;
if (chip->set_affinity)
chip->irq_set_affinity = compat_irq_set_affinity;
if (chip->set_type)
chip->irq_set_type = compat_irq_set_type;
if (chip->set_wake)
chip->irq_set_wake = compat_irq_set_wake;
if (chip->retrigger)
chip->irq_retrigger = compat_irq_retrigger;
#endif
}
static inline void mask_ack_irq(struct irq_desc *desc)
{
if (desc->irq_data.chip->irq_mask_ack)
desc->irq_data.chip->irq_mask_ack(&desc->irq_data);
else {
desc->irq_data.chip->irq_mask(&desc->irq_data);
if (desc->irq_data.chip->irq_ack)
desc->irq_data.chip->irq_ack(&desc->irq_data);
}
desc->status |= IRQ_MASKED;
}
static inline void mask_irq(struct irq_desc *desc)
{
if (desc->irq_data.chip->irq_mask) {
desc->irq_data.chip->irq_mask(&desc->irq_data);
desc->status |= IRQ_MASKED;
}
}
static inline void unmask_irq(struct irq_desc *desc)
{
if (desc->irq_data.chip->irq_unmask) {
desc->irq_data.chip->irq_unmask(&desc->irq_data);
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);
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);
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);
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->irq_data.chip->irq_eoi(&desc->irq_data);
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);
goto out_unlock;
}
kstat_incr_irqs_this_cpu(irq, desc);
/* Start handling the irq */
desc->irq_data.chip->irq_ack(&desc->irq_data);
/* 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);
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);
}
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->irq_data.chip->irq_ack)
desc->irq_data.chip->irq_ack(&desc->irq_data);
action_ret = handle_IRQ_event(irq, desc->action);
if (!noirqdebug)
note_interrupt(irq, desc, action_ret);
if (desc->irq_data.chip->irq_eoi)
desc->irq_data.chip->irq_eoi(&desc->irq_data);
}
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->irq_data.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->irq_data.chip = &dummy_irq_chip;
}
chip_bus_lock(desc);
raw_spin_lock_irqsave(&desc->lock, flags);
/* Uninstall? */
if (handle == handle_bad_irq) {
if (desc->irq_data.chip != &no_irq_chip)
mask_ack_irq(desc);
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->irq_data.chip->irq_startup(&desc->irq_data);
}
raw_spin_unlock_irqrestore(&desc->lock, flags);
chip_bus_sync_unlock(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 irq_modify_status(unsigned int irq, unsigned long clr, unsigned long set)
{
struct irq_desc *desc = irq_to_desc(irq);
unsigned long flags;
if (!desc)
return;
/* Sanitize flags */
set &= IRQF_MODIFY_MASK;
clr &= IRQF_MODIFY_MASK;
raw_spin_lock_irqsave(&desc->lock, flags);
desc->status &= ~clr;
desc->status |= set;
raw_spin_unlock_irqrestore(&desc->lock, flags);
}