- 根目录:
- kernel
- irq
- 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 <trace/events/irq.h>
#include "internals.h"
/**
* irq_set_chip - set the irq chip for an irq
* @irq: irq number
* @chip: pointer to irq chip description structure
*/
int irq_set_chip(unsigned int irq, struct irq_chip *chip)
{
unsigned long flags;
struct irq_desc *desc = irq_get_desc_lock(irq, &flags, 0);
if (!desc)
return -EINVAL;
if (!chip)
chip = &no_irq_chip;
desc->irq_data.chip = chip;
irq_put_desc_unlock(desc, flags);
/*
* For !CONFIG_SPARSE_IRQ make the irq show up in
* allocated_irqs. For the CONFIG_SPARSE_IRQ case, it is
* already marked, and this call is harmless.
*/
irq_reserve_irq(irq);
return 0;
}
EXPORT_SYMBOL(irq_set_chip);
/**
* irq_set_type - set the irq trigger type for an irq
* @irq: irq number
* @type: IRQ_TYPE_{LEVEL,EDGE}_* value - see include/linux/irq.h
*/
int irq_set_irq_type(unsigned int irq, unsigned int type)
{
unsigned long flags;
struct irq_desc *desc = irq_get_desc_buslock(irq, &flags, IRQ_GET_DESC_CHECK_GLOBAL);
int ret = 0;
if (!desc)
return -EINVAL;
type &= IRQ_TYPE_SENSE_MASK;
ret = __irq_set_trigger(desc, irq, type);
irq_put_desc_busunlock(desc, flags);
return ret;
}
EXPORT_SYMBOL(irq_set_irq_type);
/**
* irq_set_handler_data - set irq handler data for an irq
* @irq: Interrupt number
* @data: Pointer to interrupt specific data
*
* Set the hardware irq controller data for an irq
*/
int irq_set_handler_data(unsigned int irq, void *data)
{
unsigned long flags;
struct irq_desc *desc = irq_get_desc_lock(irq, &flags, 0);
if (!desc)
return -EINVAL;
desc->irq_data.handler_data = data;
irq_put_desc_unlock(desc, flags);
return 0;
}
EXPORT_SYMBOL(irq_set_handler_data);
/**
* irq_set_msi_desc - 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 irq_set_msi_desc(unsigned int irq, struct msi_desc *entry)
{
unsigned long flags;
struct irq_desc *desc = irq_get_desc_lock(irq, &flags, IRQ_GET_DESC_CHECK_GLOBAL);
if (!desc)
return -EINVAL;
desc->irq_data.msi_desc = entry;
if (entry)
entry->irq = irq;
irq_put_desc_unlock(desc, flags);
return 0;
}
/**
* irq_set_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 irq_set_chip_data(unsigned int irq, void *data)
{
unsigned long flags;
struct irq_desc *desc = irq_get_desc_lock(irq, &flags, 0);
if (!desc)
return -EINVAL;
desc->irq_data.chip_data = data;
irq_put_desc_unlock(desc, flags);
return 0;
}
EXPORT_SYMBOL(irq_set_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);
static void irq_state_clr_disabled(struct irq_desc *desc)
{
irqd_clear(&desc->irq_data, IRQD_IRQ_DISABLED);
}
static void irq_state_set_disabled(struct irq_desc *desc)
{
irqd_set(&desc->irq_data, IRQD_IRQ_DISABLED);
}
static void irq_state_clr_masked(struct irq_desc *desc)
{
irqd_clear(&desc->irq_data, IRQD_IRQ_MASKED);
}
static void irq_state_set_masked(struct irq_desc *desc)
{
irqd_set(&desc->irq_data, IRQD_IRQ_MASKED);
}
int irq_startup(struct irq_desc *desc, bool resend)
{
int ret = 0;
irq_state_clr_disabled(desc);
desc->depth = 0;
if (desc->irq_data.chip->irq_startup) {
ret = desc->irq_data.chip->irq_startup(&desc->irq_data);
irq_state_clr_masked(desc);
} else {
irq_enable(desc);
}
if (resend)
check_irq_resend(desc, desc->irq_data.irq);
return ret;
}
void irq_shutdown(struct irq_desc *desc)
{
irq_state_set_disabled(desc);
desc->depth = 1;
if (desc->irq_data.chip->irq_shutdown)
desc->irq_data.chip->irq_shutdown(&desc->irq_data);
else if (desc->irq_data.chip->irq_disable)
desc->irq_data.chip->irq_disable(&desc->irq_data);
else
desc->irq_data.chip->irq_mask(&desc->irq_data);
irq_state_set_masked(desc);
}
void irq_enable(struct irq_desc *desc)
{
irq_state_clr_disabled(desc);
if (desc->irq_data.chip->irq_enable)
desc->irq_data.chip->irq_enable(&desc->irq_data);
else
desc->irq_data.chip->irq_unmask(&desc->irq_data);
irq_state_clr_masked(desc);
}
void irq_disable(struct irq_desc *desc)
{
irq_state_set_disabled(desc);
if (desc->irq_data.chip->irq_disable) {
desc->irq_data.chip->irq_disable(&desc->irq_data);
irq_state_set_masked(desc);
}
}
void irq_percpu_enable(struct irq_desc *desc, unsigned int cpu)
{
if (desc->irq_data.chip->irq_enable)
desc->irq_data.chip->irq_enable(&desc->irq_data);
else
desc->irq_data.chip->irq_unmask(&desc->irq_data);
cpumask_set_cpu(cpu, desc->percpu_enabled);
}
void irq_percpu_disable(struct irq_desc *desc, unsigned int cpu)
{
if (desc->irq_data.chip->irq_disable)
desc->irq_data.chip->irq_disable(&desc->irq_data);
else
desc->irq_data.chip->irq_mask(&desc->irq_data);
cpumask_clear_cpu(cpu, desc->percpu_enabled);
}
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);
}
irq_state_set_masked(desc);
}
void mask_irq(struct irq_desc *desc)
{
if (desc->irq_data.chip->irq_mask) {
desc->irq_data.chip->irq_mask(&desc->irq_data);
irq_state_set_masked(desc);
}
}
void unmask_irq(struct irq_desc *desc)
{
if (desc->irq_data.chip->irq_unmask) {
desc->irq_data.chip->irq_unmask(&desc->irq_data);
irq_state_clr_masked(desc);
}
}
/*
* 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 || irqd_irq_disabled(&desc->irq_data)))
goto out_unlock;
irqd_set(&desc->irq_data, IRQD_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);
irqd_clear(&desc->irq_data, IRQD_IRQ_INPROGRESS);
out_unlock:
raw_spin_unlock_irq(&desc->lock);
}
EXPORT_SYMBOL_GPL(handle_nested_irq);
static bool irq_check_poll(struct irq_desc *desc)
{
if (!(desc->istate & IRQS_POLL_INPROGRESS))
return false;
return irq_wait_for_poll(desc);
}
/**
* 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)
{
raw_spin_lock(&desc->lock);
if (unlikely(irqd_irq_inprogress(&desc->irq_data)))
if (!irq_check_poll(desc))
goto out_unlock;
desc->istate &= ~(IRQS_REPLAY | IRQS_WAITING);
kstat_incr_irqs_this_cpu(irq, desc);
if (unlikely(!desc->action || irqd_irq_disabled(&desc->irq_data)))
goto out_unlock;
handle_irq_event(desc);
out_unlock:
raw_spin_unlock(&desc->lock);
}
EXPORT_SYMBOL_GPL(handle_simple_irq);
/*
* Called unconditionally from handle_level_irq() and only for oneshot
* interrupts from handle_fasteoi_irq()
*/
static void cond_unmask_irq(struct irq_desc *desc)
{
/*
* We need to unmask in the following cases:
* - Standard level irq (IRQF_ONESHOT is not set)
* - Oneshot irq which did not wake the thread (caused by a
* spurious interrupt or a primary handler handling it
* completely).
*/
if (!irqd_irq_disabled(&desc->irq_data) &&
irqd_irq_masked(&desc->irq_data) && !desc->threads_oneshot)
unmask_irq(desc);
}
/**
* 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)
{
raw_spin_lock(&desc->lock);
mask_ack_irq(desc);
if (unlikely(irqd_irq_inprogress(&desc->irq_data)))
if (!irq_check_poll(desc))
goto out_unlock;
desc->istate &= ~(IRQS_REPLAY | IRQS_WAITING);
kstat_incr_irqs_this_cpu(irq, desc);
/*
* If its disabled or no action available
* keep it masked and get out of here
*/
if (unlikely(!desc->action || irqd_irq_disabled(&desc->irq_data)))
goto out_unlock;
handle_irq_event(desc);
cond_unmask_irq(desc);
out_unlock:
raw_spin_unlock(&desc->lock);
}
EXPORT_SYMBOL_GPL(handle_level_irq);
#ifdef CONFIG_IRQ_PREFLOW_FASTEOI
static inline void preflow_handler(struct irq_desc *desc)
{
if (desc->preflow_handler)
desc->preflow_handler(&desc->irq_data);
}
#else
static inline void preflow_handler(struct irq_desc *desc) { }
#endif
/**
* 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)
{
raw_spin_lock(&desc->lock);
if (unlikely(irqd_irq_inprogress(&desc->irq_data)))
if (!irq_check_poll(desc))
goto out;
desc->istate &= ~(IRQS_REPLAY | IRQS_WAITING);
kstat_incr_irqs_this_cpu(irq, desc);
/*
* If its disabled or no action available
* then mask it and get out of here:
*/
if (unlikely(!desc->action || irqd_irq_disabled(&desc->irq_data))) {
desc->istate |= IRQS_PENDING;
mask_irq(desc);
goto out;
}
if (desc->istate & IRQS_ONESHOT)
mask_irq(desc);
preflow_handler(desc);
handle_irq_event(desc);
if (desc->istate & IRQS_ONESHOT)
cond_unmask_irq(desc);
out_eoi:
desc->irq_data.chip->irq_eoi(&desc->irq_data);
out_unlock:
raw_spin_unlock(&desc->lock);
return;
out:
if (!(desc->irq_data.chip->flags & IRQCHIP_EOI_IF_HANDLED))
goto out_eoi;
goto out_unlock;
}
/**
* 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 occurrence 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->istate &= ~(IRQS_REPLAY | IRQS_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(irqd_irq_disabled(&desc->irq_data) ||
irqd_irq_inprogress(&desc->irq_data) || !desc->action)) {
if (!irq_check_poll(desc)) {
desc->istate |= IRQS_PENDING;
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);
do {
if (unlikely(!desc->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->istate & IRQS_PENDING)) {
if (!irqd_irq_disabled(&desc->irq_data) &&
irqd_irq_masked(&desc->irq_data))
unmask_irq(desc);
}
handle_irq_event(desc);
} while ((desc->istate & IRQS_PENDING) &&
!irqd_irq_disabled(&desc->irq_data));
out_unlock:
raw_spin_unlock(&desc->lock);
}
EXPORT_SYMBOL(handle_edge_irq);
#ifdef CONFIG_IRQ_EDGE_EOI_HANDLER
/**
* handle_edge_eoi_irq - edge eoi type IRQ handler
* @irq: the interrupt number
* @desc: the interrupt description structure for this irq
*
* Similar as the above handle_edge_irq, but using eoi and w/o the
* mask/unmask logic.
*/
void handle_edge_eoi_irq(unsigned int irq, struct irq_desc *desc)
{
struct irq_chip *chip = irq_desc_get_chip(desc);
raw_spin_lock(&desc->lock);
desc->istate &= ~(IRQS_REPLAY | IRQS_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(irqd_irq_disabled(&desc->irq_data) ||
irqd_irq_inprogress(&desc->irq_data) || !desc->action)) {
if (!irq_check_poll(desc)) {
desc->istate |= IRQS_PENDING;
goto out_eoi;
}
}
kstat_incr_irqs_this_cpu(irq, desc);
do {
if (unlikely(!desc->action))
goto out_eoi;
handle_irq_event(desc);
} while ((desc->istate & IRQS_PENDING) &&
!irqd_irq_disabled(&desc->irq_data));
out_eoi:
chip->irq_eoi(&desc->irq_data);
raw_spin_unlock(&desc->lock);
}
#endif
/**
* 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)
{
struct irq_chip *chip = irq_desc_get_chip(desc);
kstat_incr_irqs_this_cpu(irq, desc);
if (chip->irq_ack)
chip->irq_ack(&desc->irq_data);
handle_irq_event_percpu(desc, desc->action);
if (chip->irq_eoi)
chip->irq_eoi(&desc->irq_data);
}
/**
* handle_percpu_devid_irq - Per CPU local irq handler with per cpu dev ids
* @irq: the interrupt number
* @desc: the interrupt description structure for this irq
*
* Per CPU interrupts on SMP machines without locking requirements. Same as
* handle_percpu_irq() above but with the following extras:
*
* action->percpu_dev_id is a pointer to percpu variables which
* contain the real device id for the cpu on which this handler is
* called
*/
void handle_percpu_devid_irq(unsigned int irq, struct irq_desc *desc)
{
struct irq_chip *chip = irq_desc_get_chip(desc);
struct irqaction *action = desc->action;
void *dev_id = __this_cpu_ptr(action->percpu_dev_id);
irqreturn_t res;
kstat_incr_irqs_this_cpu(irq, desc);
if (chip->irq_ack)
chip->irq_ack(&desc->irq_data);
trace_irq_handler_entry(irq, action);
res = action->handler(irq, dev_id);
trace_irq_handler_exit(irq, action, res);
if (chip->irq_eoi)
chip->irq_eoi(&desc->irq_data);
}
void
__irq_set_handler(unsigned int irq, irq_flow_handler_t handle, int is_chained,
const char *name)
{
unsigned long flags;
struct irq_desc *desc = irq_get_desc_buslock(irq, &flags, 0);
if (!desc)
return;
if (!handle) {
handle = handle_bad_irq;
} else {
if (WARN_ON(desc->irq_data.chip == &no_irq_chip))
goto out;
}
/* Uninstall? */
if (handle == handle_bad_irq) {
if (desc->irq_data.chip != &no_irq_chip)
mask_ack_irq(desc);
irq_state_set_disabled(desc);
desc->depth = 1;
}
desc->handle_irq = handle;
desc->name = name;
if (handle != handle_bad_irq && is_chained) {
irq_settings_set_noprobe(desc);
irq_settings_set_norequest(desc);
irq_settings_set_nothread(desc);
irq_startup(desc, true);
}
out:
irq_put_desc_busunlock(desc, flags);
}
EXPORT_SYMBOL_GPL(__irq_set_handler);
void
irq_set_chip_and_handler_name(unsigned int irq, struct irq_chip *chip,
irq_flow_handler_t handle, const char *name)
{
irq_set_chip(irq, chip);
__irq_set_handler(irq, handle, 0, name);
}
void irq_modify_status(unsigned int irq, unsigned long clr, unsigned long set)
{
unsigned long flags;
struct irq_desc *desc = irq_get_desc_lock(irq, &flags, 0);
if (!desc)
return;
irq_settings_clr_and_set(desc, clr, set);
irqd_clear(&desc->irq_data, IRQD_NO_BALANCING | IRQD_PER_CPU |
IRQD_TRIGGER_MASK | IRQD_LEVEL | IRQD_MOVE_PCNTXT);
if (irq_settings_has_no_balance_set(desc))
irqd_set(&desc->irq_data, IRQD_NO_BALANCING);
if (irq_settings_is_per_cpu(desc))
irqd_set(&desc->irq_data, IRQD_PER_CPU);
if (irq_settings_can_move_pcntxt(desc))
irqd_set(&desc->irq_data, IRQD_MOVE_PCNTXT);
if (irq_settings_is_level(desc))
irqd_set(&desc->irq_data, IRQD_LEVEL);
irqd_set(&desc->irq_data, irq_settings_get_trigger_mask(desc));
irq_put_desc_unlock(desc, flags);
}
EXPORT_SYMBOL_GPL(irq_modify_status);
/**
* irq_cpu_online - Invoke all irq_cpu_online functions.
*
* Iterate through all irqs and invoke the chip.irq_cpu_online()
* for each.
*/
void irq_cpu_online(void)
{
struct irq_desc *desc;
struct irq_chip *chip;
unsigned long flags;
unsigned int irq;
for_each_active_irq(irq) {
desc = irq_to_desc(irq);
if (!desc)
continue;
raw_spin_lock_irqsave(&desc->lock, flags);
chip = irq_data_get_irq_chip(&desc->irq_data);
if (chip && chip->irq_cpu_online &&
(!(chip->flags & IRQCHIP_ONOFFLINE_ENABLED) ||
!irqd_irq_disabled(&desc->irq_data)))
chip->irq_cpu_online(&desc->irq_data);
raw_spin_unlock_irqrestore(&desc->lock, flags);
}
}
/**
* irq_cpu_offline - Invoke all irq_cpu_offline functions.
*
* Iterate through all irqs and invoke the chip.irq_cpu_offline()
* for each.
*/
void irq_cpu_offline(void)
{
struct irq_desc *desc;
struct irq_chip *chip;
unsigned long flags;
unsigned int irq;
for_each_active_irq(irq) {
desc = irq_to_desc(irq);
if (!desc)
continue;
raw_spin_lock_irqsave(&desc->lock, flags);
chip = irq_data_get_irq_chip(&desc->irq_data);
if (chip && chip->irq_cpu_offline &&
(!(chip->flags & IRQCHIP_ONOFFLINE_ENABLED) ||
!irqd_irq_disabled(&desc->irq_data)))
chip->irq_cpu_offline(&desc->irq_data);
raw_spin_unlock_irqrestore(&desc->lock, flags);
}
}