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android-kvm / linux / ff8eb4a9bae195e630667b28e68877f07218093e / . / kernel / irq / manage.c
blob: d2742af0f0fd870124c8fa189c102e8f330ff4d9 [file] [log] [blame]
// SPDX-License-Identifier: GPL-2.0
/*
* Copyright (C) 1992, 1998-2006 Linus Torvalds, Ingo Molnar
* Copyright (C) 2005-2006 Thomas Gleixner
*
* This file contains driver APIs to the irq subsystem.
*/
#define pr_fmt(fmt) "genirq: " fmt
#include <linux/irq.h>
#include <linux/kthread.h>
#include <linux/module.h>
#include <linux/random.h>
#include <linux/interrupt.h>
#include <linux/irqdomain.h>
#include <linux/slab.h>
#include <linux/sched.h>
#include <linux/sched/rt.h>
#include <linux/sched/task.h>
#include <linux/sched/isolation.h>
#include <uapi/linux/sched/types.h>
#include <linux/task_work.h>
#include "internals.h"
#if defined(CONFIG_IRQ_FORCED_THREADING) && !defined(CONFIG_PREEMPT_RT)
DEFINE_STATIC_KEY_FALSE(force_irqthreads_key);
static int __init setup_forced_irqthreads(char *arg)
{
static_branch_enable(&force_irqthreads_key);
return 0;
}
early_param("threadirqs", setup_forced_irqthreads);
#endif
static void __synchronize_hardirq(struct irq_desc *desc, bool sync_chip)
{
struct irq_data *irqd = irq_desc_get_irq_data(desc);
bool inprogress;
do {
unsigned long flags;
/*
* Wait until we're out of the critical section. This might
* give the wrong answer due to the lack of memory barriers.
*/
while (irqd_irq_inprogress(&desc->irq_data))
cpu_relax();
/* Ok, that indicated we're done: double-check carefully. */
raw_spin_lock_irqsave(&desc->lock, flags);
inprogress = irqd_irq_inprogress(&desc->irq_data);
/*
* If requested and supported, check at the chip whether it
* is in flight at the hardware level, i.e. already pending
* in a CPU and waiting for service and acknowledge.
*/
if (!inprogress && sync_chip) {
/*
* Ignore the return code. inprogress is only updated
* when the chip supports it.
*/
__irq_get_irqchip_state(irqd, IRQCHIP_STATE_ACTIVE,
&inprogress);
}
raw_spin_unlock_irqrestore(&desc->lock, flags);
/* Oops, that failed? */
} while (inprogress);
}
/**
* synchronize_hardirq - wait for pending hard IRQ handlers (on other CPUs)
* @irq: interrupt number to wait for
*
* This function waits for any pending hard IRQ handlers for this
* interrupt to complete before returning. If you use this
* function while holding a resource the IRQ handler may need you
* will deadlock. It does not take associated threaded handlers
* into account.
*
* Do not use this for shutdown scenarios where you must be sure
* that all parts (hardirq and threaded handler) have completed.
*
* Returns: false if a threaded handler is active.
*
* This function may be called - with care - from IRQ context.
*
* It does not check whether there is an interrupt in flight at the
* hardware level, but not serviced yet, as this might deadlock when
* called with interrupts disabled and the target CPU of the interrupt
* is the current CPU.
*/
bool synchronize_hardirq(unsigned int irq)
{
struct irq_desc *desc = irq_to_desc(irq);
if (desc) {
__synchronize_hardirq(desc, false);
return !atomic_read(&desc->threads_active);
}
return true;
}
EXPORT_SYMBOL(synchronize_hardirq);
/**
* synchronize_irq - wait for pending IRQ handlers (on other CPUs)
* @irq: interrupt number to wait for
*
* This function waits for any pending IRQ handlers for this interrupt
* to complete before returning. If you use this function while
* holding a resource the IRQ handler may need you will deadlock.
*
* Can only be called from preemptible code as it might sleep when
* an interrupt thread is associated to @irq.
*
* It optionally makes sure (when the irq chip supports that method)
* that the interrupt is not pending in any CPU and waiting for
* service.
*/
void synchronize_irq(unsigned int irq)
{
struct irq_desc *desc = irq_to_desc(irq);
if (desc) {
__synchronize_hardirq(desc, true);
/*
* We made sure that no hardirq handler is
* running. Now verify that no threaded handlers are
* active.
*/
wait_event(desc->wait_for_threads,
!atomic_read(&desc->threads_active));
}
}
EXPORT_SYMBOL(synchronize_irq);
#ifdef CONFIG_SMP
cpumask_var_t irq_default_affinity;
static bool __irq_can_set_affinity(struct irq_desc *desc)
{
if (!desc || !irqd_can_balance(&desc->irq_data) ||
!desc->irq_data.chip || !desc->irq_data.chip->irq_set_affinity)
return false;
return true;
}
/**
* irq_can_set_affinity - Check if the affinity of a given irq can be set
* @irq: Interrupt to check
*
*/
int irq_can_set_affinity(unsigned int irq)
{
return __irq_can_set_affinity(irq_to_desc(irq));
}
/**
* irq_can_set_affinity_usr - Check if affinity of a irq can be set from user space
* @irq: Interrupt to check
*
* Like irq_can_set_affinity() above, but additionally checks for the
* AFFINITY_MANAGED flag.
*/
bool irq_can_set_affinity_usr(unsigned int irq)
{
struct irq_desc *desc = irq_to_desc(irq);
return __irq_can_set_affinity(desc) &&
!irqd_affinity_is_managed(&desc->irq_data);
}
/**
* irq_set_thread_affinity - Notify irq threads to adjust affinity
* @desc: irq descriptor which has affinity changed
*
* We just set IRQTF_AFFINITY and delegate the affinity setting
* to the interrupt thread itself. We can not call
* set_cpus_allowed_ptr() here as we hold desc->lock and this
* code can be called from hard interrupt context.
*/
void irq_set_thread_affinity(struct irq_desc *desc)
{
struct irqaction *action;
for_each_action_of_desc(desc, action) {
if (action->thread)
set_bit(IRQTF_AFFINITY, &action->thread_flags);
if (action->secondary && action->secondary->thread)
set_bit(IRQTF_AFFINITY, &action->secondary->thread_flags);
}
}
#ifdef CONFIG_GENERIC_IRQ_EFFECTIVE_AFF_MASK
static void irq_validate_effective_affinity(struct irq_data *data)
{
const struct cpumask *m = irq_data_get_effective_affinity_mask(data);
struct irq_chip *chip = irq_data_get_irq_chip(data);
if (!cpumask_empty(m))
return;
pr_warn_once("irq_chip %s did not update eff. affinity mask of irq %u\n",
chip->name, data->irq);
}
#else
static inline void irq_validate_effective_affinity(struct irq_data *data) { }
#endif
int irq_do_set_affinity(struct irq_data *data, const struct cpumask *mask,
bool force)
{
struct irq_desc *desc = irq_data_to_desc(data);
struct irq_chip *chip = irq_data_get_irq_chip(data);
const struct cpumask *prog_mask;
int ret;
static DEFINE_RAW_SPINLOCK(tmp_mask_lock);
static struct cpumask tmp_mask;
if (!chip || !chip->irq_set_affinity)
return -EINVAL;
raw_spin_lock(&tmp_mask_lock);
/*
* If this is a managed interrupt and housekeeping is enabled on
* it check whether the requested affinity mask intersects with
* a housekeeping CPU. If so, then remove the isolated CPUs from
* the mask and just keep the housekeeping CPU(s). This prevents
* the affinity setter from routing the interrupt to an isolated
* CPU to avoid that I/O submitted from a housekeeping CPU causes
* interrupts on an isolated one.
*
* If the masks do not intersect or include online CPU(s) then
* keep the requested mask. The isolated target CPUs are only
* receiving interrupts when the I/O operation was submitted
* directly from them.
*
* If all housekeeping CPUs in the affinity mask are offline, the
* interrupt will be migrated by the CPU hotplug code once a
* housekeeping CPU which belongs to the affinity mask comes
* online.
*/
if (irqd_affinity_is_managed(data) &&
housekeeping_enabled(HK_TYPE_MANAGED_IRQ)) {
const struct cpumask *hk_mask;
hk_mask = housekeeping_cpumask(HK_TYPE_MANAGED_IRQ);
cpumask_and(&tmp_mask, mask, hk_mask);
if (!cpumask_intersects(&tmp_mask, cpu_online_mask))
prog_mask = mask;
else
prog_mask = &tmp_mask;
} else {
prog_mask = mask;
}
/*
* Make sure we only provide online CPUs to the irqchip,
* unless we are being asked to force the affinity (in which
* case we do as we are told).
*/
cpumask_and(&tmp_mask, prog_mask, cpu_online_mask);
if (!force && !cpumask_empty(&tmp_mask))
ret = chip->irq_set_affinity(data, &tmp_mask, force);
else if (force)
ret = chip->irq_set_affinity(data, mask, force);
else
ret = -EINVAL;
raw_spin_unlock(&tmp_mask_lock);
switch (ret) {
case IRQ_SET_MASK_OK:
case IRQ_SET_MASK_OK_DONE:
cpumask_copy(desc->irq_common_data.affinity, mask);
fallthrough;
case IRQ_SET_MASK_OK_NOCOPY:
irq_validate_effective_affinity(data);
irq_set_thread_affinity(desc);
ret = 0;
}
return ret;
}
#ifdef CONFIG_GENERIC_PENDING_IRQ
static inline int irq_set_affinity_pending(struct irq_data *data,
const struct cpumask *dest)
{
struct irq_desc *desc = irq_data_to_desc(data);
irqd_set_move_pending(data);
irq_copy_pending(desc, dest);
return 0;
}
#else
static inline int irq_set_affinity_pending(struct irq_data *data,
const struct cpumask *dest)
{
return -EBUSY;
}
#endif
static int irq_try_set_affinity(struct irq_data *data,
const struct cpumask *dest, bool force)
{
int ret = irq_do_set_affinity(data, dest, force);
/*
* In case that the underlying vector management is busy and the
* architecture supports the generic pending mechanism then utilize
* this to avoid returning an error to user space.
*/
if (ret == -EBUSY && !force)
ret = irq_set_affinity_pending(data, dest);
return ret;
}
static bool irq_set_affinity_deactivated(struct irq_data *data,
const struct cpumask *mask)
{
struct irq_desc *desc = irq_data_to_desc(data);
/*
* Handle irq chips which can handle affinity only in activated
* state correctly
*
* If the interrupt is not yet activated, just store the affinity
* mask and do not call the chip driver at all. On activation the
* driver has to make sure anyway that the interrupt is in a
* usable state so startup works.
*/
if (!IS_ENABLED(CONFIG_IRQ_DOMAIN_HIERARCHY) ||
irqd_is_activated(data) || !irqd_affinity_on_activate(data))
return false;
cpumask_copy(desc->irq_common_data.affinity, mask);
irq_data_update_effective_affinity(data, mask);
irqd_set(data, IRQD_AFFINITY_SET);
return true;
}
int irq_set_affinity_locked(struct irq_data *data, const struct cpumask *mask,
bool force)
{
struct irq_chip *chip = irq_data_get_irq_chip(data);
struct irq_desc *desc = irq_data_to_desc(data);
int ret = 0;
if (!chip || !chip->irq_set_affinity)
return -EINVAL;
if (irq_set_affinity_deactivated(data, mask))
return 0;
if (irq_can_move_pcntxt(data) && !irqd_is_setaffinity_pending(data)) {
ret = irq_try_set_affinity(data, mask, force);
} else {
irqd_set_move_pending(data);
irq_copy_pending(desc, mask);
}
if (desc->affinity_notify) {
kref_get(&desc->affinity_notify->kref);
if (!schedule_work(&desc->affinity_notify->work)) {
/* Work was already scheduled, drop our extra ref */
kref_put(&desc->affinity_notify->kref,
desc->affinity_notify->release);
}
}
irqd_set(data, IRQD_AFFINITY_SET);
return ret;
}
/**
* irq_update_affinity_desc - Update affinity management for an interrupt
* @irq: The interrupt number to update
* @affinity: Pointer to the affinity descriptor
*
* This interface can be used to configure the affinity management of
* interrupts which have been allocated already.
*
* There are certain limitations on when it may be used - attempts to use it
* for when the kernel is configured for generic IRQ reservation mode (in
* config GENERIC_IRQ_RESERVATION_MODE) will fail, as it may conflict with
* managed/non-managed interrupt accounting. In addition, attempts to use it on
* an interrupt which is already started or which has already been configured
* as managed will also fail, as these mean invalid init state or double init.
*/
int irq_update_affinity_desc(unsigned int irq,
struct irq_affinity_desc *affinity)
{
struct irq_desc *desc;
unsigned long flags;
bool activated;
int ret = 0;
/*
* Supporting this with the reservation scheme used by x86 needs
* some more thought. Fail it for now.
*/
if (IS_ENABLED(CONFIG_GENERIC_IRQ_RESERVATION_MODE))
return -EOPNOTSUPP;
desc = irq_get_desc_buslock(irq, &flags, 0);
if (!desc)
return -EINVAL;
/* Requires the interrupt to be shut down */
if (irqd_is_started(&desc->irq_data)) {
ret = -EBUSY;
goto out_unlock;
}
/* Interrupts which are already managed cannot be modified */
if (irqd_affinity_is_managed(&desc->irq_data)) {
ret = -EBUSY;
goto out_unlock;
}
/*
* Deactivate the interrupt. That's required to undo
* anything an earlier activation has established.
*/
activated = irqd_is_activated(&desc->irq_data);
if (activated)
irq_domain_deactivate_irq(&desc->irq_data);
if (affinity->is_managed) {
irqd_set(&desc->irq_data, IRQD_AFFINITY_MANAGED);
irqd_set(&desc->irq_data, IRQD_MANAGED_SHUTDOWN);
}
cpumask_copy(desc->irq_common_data.affinity, &affinity->mask);
/* Restore the activation state */
if (activated)
irq_domain_activate_irq(&desc->irq_data, false);
out_unlock:
irq_put_desc_busunlock(desc, flags);
return ret;
}
static int __irq_set_affinity(unsigned int irq, const struct cpumask *mask,
bool force)
{
struct irq_desc *desc = irq_to_desc(irq);
unsigned long flags;
int ret;
if (!desc)
return -EINVAL;
raw_spin_lock_irqsave(&desc->lock, flags);
ret = irq_set_affinity_locked(irq_desc_get_irq_data(desc), mask, force);
raw_spin_unlock_irqrestore(&desc->lock, flags);
return ret;
}
/**
* irq_set_affinity - Set the irq affinity of a given irq
* @irq: Interrupt to set affinity
* @cpumask: cpumask
*
* Fails if cpumask does not contain an online CPU
*/
int irq_set_affinity(unsigned int irq, const struct cpumask *cpumask)
{
return __irq_set_affinity(irq, cpumask, false);
}
EXPORT_SYMBOL_GPL(irq_set_affinity);
/**
* irq_force_affinity - Force the irq affinity of a given irq
* @irq: Interrupt to set affinity
* @cpumask: cpumask
*
* Same as irq_set_affinity, but without checking the mask against
* online cpus.
*
* Solely for low level cpu hotplug code, where we need to make per
* cpu interrupts affine before the cpu becomes online.
*/
int irq_force_affinity(unsigned int irq, const struct cpumask *cpumask)
{
return __irq_set_affinity(irq, cpumask, true);
}
EXPORT_SYMBOL_GPL(irq_force_affinity);
int __irq_apply_affinity_hint(unsigned int irq, const struct cpumask *m,
bool setaffinity)
{
unsigned long flags;
struct irq_desc *desc = irq_get_desc_lock(irq, &flags, IRQ_GET_DESC_CHECK_GLOBAL);
if (!desc)
return -EINVAL;
desc->affinity_hint = m;
irq_put_desc_unlock(desc, flags);
if (m && setaffinity)
__irq_set_affinity(irq, m, false);
return 0;
}
EXPORT_SYMBOL_GPL(__irq_apply_affinity_hint);
static void irq_affinity_notify(struct work_struct *work)
{
struct irq_affinity_notify *notify =
container_of(work, struct irq_affinity_notify, work);
struct irq_desc *desc = irq_to_desc(notify->irq);
cpumask_var_t cpumask;
unsigned long flags;
if (!desc || !alloc_cpumask_var(&cpumask, GFP_KERNEL))
goto out;
raw_spin_lock_irqsave(&desc->lock, flags);
if (irq_move_pending(&desc->irq_data))
irq_get_pending(cpumask, desc);
else
cpumask_copy(cpumask, desc->irq_common_data.affinity);
raw_spin_unlock_irqrestore(&desc->lock, flags);
notify->notify(notify, cpumask);
free_cpumask_var(cpumask);
out:
kref_put(&notify->kref, notify->release);
}
/**
* irq_set_affinity_notifier - control notification of IRQ affinity changes
* @irq: Interrupt for which to enable/disable notification
* @notify: Context for notification, or %NULL to disable
* notification. Function pointers must be initialised;
* the other fields will be initialised by this function.
*
* Must be called in process context. Notification may only be enabled
* after the IRQ is allocated and must be disabled before the IRQ is
* freed using free_irq().
*/
int
irq_set_affinity_notifier(unsigned int irq, struct irq_affinity_notify *notify)
{
struct irq_desc *desc = irq_to_desc(irq);
struct irq_affinity_notify *old_notify;
unsigned long flags;
/* The release function is promised process context */
might_sleep();
if (!desc || desc->istate & IRQS_NMI)
return -EINVAL;
/* Complete initialisation of *notify */
if (notify) {
notify->irq = irq;
kref_init(&notify->kref);
INIT_WORK(&notify->work, irq_affinity_notify);
}
raw_spin_lock_irqsave(&desc->lock, flags);
old_notify = desc->affinity_notify;
desc->affinity_notify = notify;
raw_spin_unlock_irqrestore(&desc->lock, flags);
if (old_notify) {
if (cancel_work_sync(&old_notify->work)) {
/* Pending work had a ref, put that one too */
kref_put(&old_notify->kref, old_notify->release);
}
kref_put(&old_notify->kref, old_notify->release);
}
return 0;
}
EXPORT_SYMBOL_GPL(irq_set_affinity_notifier);
#ifndef CONFIG_AUTO_IRQ_AFFINITY
/*
* Generic version of the affinity autoselector.
*/
int irq_setup_affinity(struct irq_desc *desc)
{
struct cpumask *set = irq_default_affinity;
int ret, node = irq_desc_get_node(desc);
static DEFINE_RAW_SPINLOCK(mask_lock);
static struct cpumask mask;
/* Excludes PER_CPU and NO_BALANCE interrupts */
if (!__irq_can_set_affinity(desc))
return 0;
raw_spin_lock(&mask_lock);
/*
* Preserve the managed affinity setting and a userspace affinity
* setup, but make sure that one of the targets is online.
*/
if (irqd_affinity_is_managed(&desc->irq_data) ||
irqd_has_set(&desc->irq_data, IRQD_AFFINITY_SET)) {
if (cpumask_intersects(desc->irq_common_data.affinity,
cpu_online_mask))
set = desc->irq_common_data.affinity;
else
irqd_clear(&desc->irq_data, IRQD_AFFINITY_SET);
}
cpumask_and(&mask, cpu_online_mask, set);
if (cpumask_empty(&mask))
cpumask_copy(&mask, cpu_online_mask);
if (node != NUMA_NO_NODE) {
const struct cpumask *nodemask = cpumask_of_node(node);
/* make sure at least one of the cpus in nodemask is online */
if (cpumask_intersects(&mask, nodemask))
cpumask_and(&mask, &mask, nodemask);
}
ret = irq_do_set_affinity(&desc->irq_data, &mask, false);
raw_spin_unlock(&mask_lock);
return ret;
}
#else
/* Wrapper for ALPHA specific affinity selector magic */
int irq_setup_affinity(struct irq_desc *desc)
{
return irq_select_affinity(irq_desc_get_irq(desc));
}
#endif /* CONFIG_AUTO_IRQ_AFFINITY */
#endif /* CONFIG_SMP */
/**
* irq_set_vcpu_affinity - Set vcpu affinity for the interrupt
* @irq: interrupt number to set affinity
* @vcpu_info: vCPU specific data or pointer to a percpu array of vCPU
* specific data for percpu_devid interrupts
*
* This function uses the vCPU specific data to set the vCPU
* affinity for an irq. The vCPU specific data is passed from
* outside, such as KVM. One example code path is as below:
* KVM -> IOMMU -> irq_set_vcpu_affinity().
*/
int irq_set_vcpu_affinity(unsigned int irq, void *vcpu_info)
{
unsigned long flags;
struct irq_desc *desc = irq_get_desc_lock(irq, &flags, 0);
struct irq_data *data;
struct irq_chip *chip;
int ret = -ENOSYS;
if (!desc)
return -EINVAL;
data = irq_desc_get_irq_data(desc);
do {
chip = irq_data_get_irq_chip(data);
if (chip && chip->irq_set_vcpu_affinity)
break;
#ifdef CONFIG_IRQ_DOMAIN_HIERARCHY
data = data->parent_data;
#else
data = NULL;
#endif
} while (data);
if (data)
ret = chip->irq_set_vcpu_affinity(data, vcpu_info);
irq_put_desc_unlock(desc, flags);
return ret;
}
EXPORT_SYMBOL_GPL(irq_set_vcpu_affinity);
void __disable_irq(struct irq_desc *desc)
{
if (!desc->depth++)
irq_disable(desc);
}
static int __disable_irq_nosync(unsigned int irq)
{
unsigned long flags;
struct irq_desc *desc = irq_get_desc_buslock(irq, &flags, IRQ_GET_DESC_CHECK_GLOBAL);
if (!desc)
return -EINVAL;
__disable_irq(desc);
irq_put_desc_busunlock(desc, flags);
return 0;
}
/**
* disable_irq_nosync - disable an irq without waiting
* @irq: Interrupt to disable
*
* Disable the selected interrupt line. Disables and Enables are
* nested.
* Unlike disable_irq(), this function does not ensure existing
* instances of the IRQ handler have completed before returning.
*
* This function may be called from IRQ context.
*/
void disable_irq_nosync(unsigned int irq)
{
__disable_irq_nosync(irq);
}
EXPORT_SYMBOL(disable_irq_nosync);
/**
* disable_irq - disable an irq and wait for completion
* @irq: Interrupt to disable
*
* Disable the selected interrupt line. Enables and Disables are
* nested.
* This function waits for any pending IRQ handlers for this interrupt
* to complete before returning. If you use this function while
* holding a resource the IRQ handler may need you will deadlock.
*
* Can only be called from preemptible code as it might sleep when
* an interrupt thread is associated to @irq.
*
*/
void disable_irq(unsigned int irq)
{
might_sleep();
if (!__disable_irq_nosync(irq))
synchronize_irq(irq);
}
EXPORT_SYMBOL(disable_irq);
/**
* disable_hardirq - disables an irq and waits for hardirq completion
* @irq: Interrupt to disable
*
* Disable the selected interrupt line. Enables and Disables are
* nested.
* This function waits for any pending hard IRQ handlers for this
* interrupt to complete before returning. If you use this function while
* holding a resource the hard IRQ handler may need you will deadlock.
*
* When used to optimistically disable an interrupt from atomic context
* the return value must be checked.
*
* Returns: false if a threaded handler is active.
*
* This function may be called - with care - from IRQ context.
*/
bool disable_hardirq(unsigned int irq)
{
if (!__disable_irq_nosync(irq))
return synchronize_hardirq(irq);
return false;
}
EXPORT_SYMBOL_GPL(disable_hardirq);
/**
* disable_nmi_nosync - disable an nmi without waiting
* @irq: Interrupt to disable
*
* Disable the selected interrupt line. Disables and enables are
* nested.
* The interrupt to disable must have been requested through request_nmi.
* Unlike disable_nmi(), this function does not ensure existing
* instances of the IRQ handler have completed before returning.
*/
void disable_nmi_nosync(unsigned int irq)
{
disable_irq_nosync(irq);
}
void __enable_irq(struct irq_desc *desc)
{
switch (desc->depth) {
case 0:
err_out:
WARN(1, KERN_WARNING "Unbalanced enable for IRQ %d\n",
irq_desc_get_irq(desc));
break;
case 1: {
if (desc->istate & IRQS_SUSPENDED)
goto err_out;
/* Prevent probing on this irq: */
irq_settings_set_noprobe(desc);
/*
* Call irq_startup() not irq_enable() here because the
* interrupt might be marked NOAUTOEN. So irq_startup()
* needs to be invoked when it gets enabled the first
* time. If it was already started up, then irq_startup()
* will invoke irq_enable() under the hood.
*/
irq_startup(desc, IRQ_RESEND, IRQ_START_FORCE);
break;
}
default:
desc->depth--;
}
}
/**
* enable_irq - enable handling of an irq
* @irq: Interrupt to enable
*
* Undoes the effect of one call to disable_irq(). If this
* matches the last disable, processing of interrupts on this
* IRQ line is re-enabled.
*
* This function may be called from IRQ context only when
* desc->irq_data.chip->bus_lock and desc->chip->bus_sync_unlock are NULL !
*/
void enable_irq(unsigned int irq)
{
unsigned long flags;
struct irq_desc *desc = irq_get_desc_buslock(irq, &flags, IRQ_GET_DESC_CHECK_GLOBAL);
if (!desc)
return;
if (WARN(!desc->irq_data.chip,
KERN_ERR "enable_irq before setup/request_irq: irq %u\n", irq))
goto out;
__enable_irq(desc);
out:
irq_put_desc_busunlock(desc, flags);
}
EXPORT_SYMBOL(enable_irq);
/**
* enable_nmi - enable handling of an nmi
* @irq: Interrupt to enable
*
* The interrupt to enable must have been requested through request_nmi.
* Undoes the effect of one call to disable_nmi(). If this
* matches the last disable, processing of interrupts on this
* IRQ line is re-enabled.
*/
void enable_nmi(unsigned int irq)
{
enable_irq(irq);
}
static int set_irq_wake_real(unsigned int irq, unsigned int on)
{
struct irq_desc *desc = irq_to_desc(irq);
int ret = -ENXIO;
if (irq_desc_get_chip(desc)->flags & IRQCHIP_SKIP_SET_WAKE)
return 0;
if (desc->irq_data.chip->irq_set_wake)
ret = desc->irq_data.chip->irq_set_wake(&desc->irq_data, on);
return ret;
}
/**
* irq_set_irq_wake - control irq power management wakeup
* @irq: interrupt to control
* @on: enable/disable power management wakeup
*
* Enable/disable power management wakeup mode, which is
* disabled by default. Enables and disables must match,
* just as they match for non-wakeup mode support.
*
* Wakeup mode lets this IRQ wake the system from sleep
* states like "suspend to RAM".
*
* Note: irq enable/disable state is completely orthogonal
* to the enable/disable state of irq wake. An irq can be
* disabled with disable_irq() and still wake the system as
* long as the irq has wake enabled. If this does not hold,
* then the underlying irq chip and the related driver need
* to be investigated.
*/
int irq_set_irq_wake(unsigned int irq, unsigned int on)
{
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;
/* Don't use NMIs as wake up interrupts please */
if (desc->istate & IRQS_NMI) {
ret = -EINVAL;
goto out_unlock;
}
/* wakeup-capable irqs can be shared between drivers that
* don't need to have the same sleep mode behaviors.
*/
if (on) {
if (desc->wake_depth++ == 0) {
ret = set_irq_wake_real(irq, on);
if (ret)
desc->wake_depth = 0;
else
irqd_set(&desc->irq_data, IRQD_WAKEUP_STATE);
}
} else {
if (desc->wake_depth == 0) {
WARN(1, "Unbalanced IRQ %d wake disable\n", irq);
} else if (--desc->wake_depth == 0) {
ret = set_irq_wake_real(irq, on);
if (ret)
desc->wake_depth = 1;
else
irqd_clear(&desc->irq_data, IRQD_WAKEUP_STATE);
}
}
out_unlock:
irq_put_desc_busunlock(desc, flags);
return ret;
}
EXPORT_SYMBOL(irq_set_irq_wake);
/*
* Internal function that tells the architecture code whether a
* particular irq has been exclusively allocated or is available
* for driver use.
*/
int can_request_irq(unsigned int irq, unsigned long irqflags)
{
unsigned long flags;
struct irq_desc *desc = irq_get_desc_lock(irq, &flags, 0);
int canrequest = 0;
if (!desc)
return 0;
if (irq_settings_can_request(desc)) {
if (!desc->action ||
irqflags & desc->action->flags & IRQF_SHARED)
canrequest = 1;
}
irq_put_desc_unlock(desc, flags);
return canrequest;
}
int __irq_set_trigger(struct irq_desc *desc, unsigned long flags)
{
struct irq_chip *chip = desc->irq_data.chip;
int ret, unmask = 0;
if (!chip || !chip->irq_set_type) {
/*
* IRQF_TRIGGER_* but the PIC does not support multiple
* flow-types?
*/
pr_debug("No set_type function for IRQ %d (%s)\n",
irq_desc_get_irq(desc),
chip ? (chip->name ? : "unknown") : "unknown");
return 0;
}
if (chip->flags & IRQCHIP_SET_TYPE_MASKED) {
if (!irqd_irq_masked(&desc->irq_data))
mask_irq(desc);
if (!irqd_irq_disabled(&desc->irq_data))
unmask = 1;
}
/* Mask all flags except trigger mode */
flags &= IRQ_TYPE_SENSE_MASK;
ret = chip->irq_set_type(&desc->irq_data, flags);
switch (ret) {
case IRQ_SET_MASK_OK:
case IRQ_SET_MASK_OK_DONE:
irqd_clear(&desc->irq_data, IRQD_TRIGGER_MASK);
irqd_set(&desc->irq_data, flags);
fallthrough;
case IRQ_SET_MASK_OK_NOCOPY:
flags = irqd_get_trigger_type(&desc->irq_data);
irq_settings_set_trigger_mask(desc, flags);
irqd_clear(&desc->irq_data, IRQD_LEVEL);
irq_settings_clr_level(desc);
if (flags & IRQ_TYPE_LEVEL_MASK) {
irq_settings_set_level(desc);
irqd_set(&desc->irq_data, IRQD_LEVEL);
}
ret = 0;
break;
default:
pr_err("Setting trigger mode %lu for irq %u failed (%pS)\n",
flags, irq_desc_get_irq(desc), chip->irq_set_type);
}
if (unmask)
unmask_irq(desc);
return ret;
}
#ifdef CONFIG_HARDIRQS_SW_RESEND
int irq_set_parent(int irq, int parent_irq)
{
unsigned long flags;
struct irq_desc *desc = irq_get_desc_lock(irq, &flags, 0);
if (!desc)
return -EINVAL;
desc->parent_irq = parent_irq;
irq_put_desc_unlock(desc, flags);
return 0;
}
EXPORT_SYMBOL_GPL(irq_set_parent);
#endif
/*
* Default primary interrupt handler for threaded interrupts. Is
* assigned as primary handler when request_threaded_irq is called
* with handler == NULL. Useful for oneshot interrupts.
*/
static irqreturn_t irq_default_primary_handler(int irq, void *dev_id)
{
return IRQ_WAKE_THREAD;
}
/*
* Primary handler for nested threaded interrupts. Should never be
* called.
*/
static irqreturn_t irq_nested_primary_handler(int irq, void *dev_id)
{
WARN(1, "Primary handler called for nested irq %d\n", irq);
return IRQ_NONE;
}
static irqreturn_t irq_forced_secondary_handler(int irq, void *dev_id)
{
WARN(1, "Secondary action handler called for irq %d\n", irq);
return IRQ_NONE;
}
static int irq_wait_for_interrupt(struct irqaction *action)
{
for (;;) {
set_current_state(TASK_INTERRUPTIBLE);
if (kthread_should_stop()) {
/* may need to run one last time */
if (test_and_clear_bit(IRQTF_RUNTHREAD,
&action->thread_flags)) {
__set_current_state(TASK_RUNNING);
return 0;
}
__set_current_state(TASK_RUNNING);
return -1;
}
if (test_and_clear_bit(IRQTF_RUNTHREAD,
&action->thread_flags)) {
__set_current_state(TASK_RUNNING);
return 0;
}
schedule();
}
}
/*
* Oneshot interrupts keep the irq line masked until the threaded
* handler finished. unmask if the interrupt has not been disabled and
* is marked MASKED.
*/
static void irq_finalize_oneshot(struct irq_desc *desc,
struct irqaction *action)
{
if (!(desc->istate & IRQS_ONESHOT) ||
action->handler == irq_forced_secondary_handler)
return;
again:
chip_bus_lock(desc);
raw_spin_lock_irq(&desc->lock);
/*
* Implausible though it may be we need to protect us against
* the following scenario:
*
* The thread is faster done than the hard interrupt handler
* on the other CPU. If we unmask the irq line then the
* interrupt can come in again and masks the line, leaves due
* to IRQS_INPROGRESS and the irq line is masked forever.
*
* This also serializes the state of shared oneshot handlers
* versus "desc->threads_oneshot |= action->thread_mask;" in
* irq_wake_thread(). See the comment there which explains the
* serialization.
*/
if (unlikely(irqd_irq_inprogress(&desc->irq_data))) {
raw_spin_unlock_irq(&desc->lock);
chip_bus_sync_unlock(desc);
cpu_relax();
goto again;
}
/*
* Now check again, whether the thread should run. Otherwise
* we would clear the threads_oneshot bit of this thread which
* was just set.
*/
if (test_bit(IRQTF_RUNTHREAD, &action->thread_flags))
goto out_unlock;
desc->threads_oneshot &= ~action->thread_mask;
if (!desc->threads_oneshot && !irqd_irq_disabled(&desc->irq_data) &&
irqd_irq_masked(&desc->irq_data))
unmask_threaded_irq(desc);
out_unlock:
raw_spin_unlock_irq(&desc->lock);
chip_bus_sync_unlock(desc);
}
#ifdef CONFIG_SMP
/*
* Check whether we need to change the affinity of the interrupt thread.
*/
static void
irq_thread_check_affinity(struct irq_desc *desc, struct irqaction *action)
{
cpumask_var_t mask;
bool valid = true;
if (!test_and_clear_bit(IRQTF_AFFINITY, &action->thread_flags))
return;
/*
* In case we are out of memory we set IRQTF_AFFINITY again and
* try again next time
*/
if (!alloc_cpumask_var(&mask, GFP_KERNEL)) {
set_bit(IRQTF_AFFINITY, &action->thread_flags);
return;
}
raw_spin_lock_irq(&desc->lock);
/*
* This code is triggered unconditionally. Check the affinity
* mask pointer. For CPU_MASK_OFFSTACK=n this is optimized out.
*/
if (cpumask_available(desc->irq_common_data.affinity)) {
const struct cpumask *m;
m = irq_data_get_effective_affinity_mask(&desc->irq_data);
cpumask_copy(mask, m);
} else {
valid = false;
}
raw_spin_unlock_irq(&desc->lock);
if (valid)
set_cpus_allowed_ptr(current, mask);
free_cpumask_var(mask);
}
#else
static inline void
irq_thread_check_affinity(struct irq_desc *desc, struct irqaction *action) { }
#endif
/*
* Interrupts which are not explicitly requested as threaded
* interrupts rely on the implicit bh/preempt disable of the hard irq
* context. So we need to disable bh here to avoid deadlocks and other
* side effects.
*/
static irqreturn_t
irq_forced_thread_fn(struct irq_desc *desc, struct irqaction *action)
{
irqreturn_t ret;
local_bh_disable();
if (!IS_ENABLED(CONFIG_PREEMPT_RT))
local_irq_disable();
ret = action->thread_fn(action->irq, action->dev_id);
if (ret == IRQ_HANDLED)
atomic_inc(&desc->threads_handled);
irq_finalize_oneshot(desc, action);
if (!IS_ENABLED(CONFIG_PREEMPT_RT))
local_irq_enable();
local_bh_enable();
return ret;
}
/*
* Interrupts explicitly requested as threaded interrupts want to be
* preemptible - many of them need to sleep and wait for slow busses to
* complete.
*/
static irqreturn_t irq_thread_fn(struct irq_desc *desc,
struct irqaction *action)
{
irqreturn_t ret;
ret = action->thread_fn(action->irq, action->dev_id);
if (ret == IRQ_HANDLED)
atomic_inc(&desc->threads_handled);
irq_finalize_oneshot(desc, action);
return ret;
}
static void wake_threads_waitq(struct irq_desc *desc)
{
if (atomic_dec_and_test(&desc->threads_active))
wake_up(&desc->wait_for_threads);
}
static void irq_thread_dtor(struct callback_head *unused)
{
struct task_struct *tsk = current;
struct irq_desc *desc;
struct irqaction *action;
if (WARN_ON_ONCE(!(current->flags & PF_EXITING)))
return;
action = kthread_data(tsk);
pr_err("exiting task \"%s\" (%d) is an active IRQ thread (irq %d)\n",
tsk->comm, tsk->pid, action->irq);
desc = irq_to_desc(action->irq);
/*
* If IRQTF_RUNTHREAD is set, we need to decrement
* desc->threads_active and wake possible waiters.
*/
if (test_and_clear_bit(IRQTF_RUNTHREAD, &action->thread_flags))
wake_threads_waitq(desc);
/* Prevent a stale desc->threads_oneshot */
irq_finalize_oneshot(desc, action);
}
static void irq_wake_secondary(struct irq_desc *desc, struct irqaction *action)
{
struct irqaction *secondary = action->secondary;
if (WARN_ON_ONCE(!secondary))
return;
raw_spin_lock_irq(&desc->lock);
__irq_wake_thread(desc, secondary);
raw_spin_unlock_irq(&desc->lock);
}
/*
* Internal function to notify that a interrupt thread is ready.
*/
static void irq_thread_set_ready(struct irq_desc *desc,
struct irqaction *action)
{
set_bit(IRQTF_READY, &action->thread_flags);
wake_up(&desc->wait_for_threads);
}
/*
* Internal function to wake up a interrupt thread and wait until it is
* ready.
*/
static void wake_up_and_wait_for_irq_thread_ready(struct irq_desc *desc,
struct irqaction *action)
{
if (!action || !action->thread)
return;
wake_up_process(action->thread);
wait_event(desc->wait_for_threads,
test_bit(IRQTF_READY, &action->thread_flags));
}
/*
* Interrupt handler thread
*/
static int irq_thread(void *data)
{
struct callback_head on_exit_work;
struct irqaction *action = data;
struct irq_desc *desc = irq_to_desc(action->irq);
irqreturn_t (*handler_fn)(struct irq_desc *desc,
struct irqaction *action);
irq_thread_set_ready(desc, action);
sched_set_fifo(current);
if (force_irqthreads() && test_bit(IRQTF_FORCED_THREAD,
&action->thread_flags))
handler_fn = irq_forced_thread_fn;
else
handler_fn = irq_thread_fn;
init_task_work(&on_exit_work, irq_thread_dtor);
task_work_add(current, &on_exit_work, TWA_NONE);
irq_thread_check_affinity(desc, action);
while (!irq_wait_for_interrupt(action)) {
irqreturn_t action_ret;
irq_thread_check_affinity(desc, action);
action_ret = handler_fn(desc, action);
if (action_ret == IRQ_WAKE_THREAD)
irq_wake_secondary(desc, action);
wake_threads_waitq(desc);
}
/*
* This is the regular exit path. __free_irq() is stopping the
* thread via kthread_stop() after calling
* synchronize_hardirq(). So neither IRQTF_RUNTHREAD nor the
* oneshot mask bit can be set.
*/
task_work_cancel(current, irq_thread_dtor);
return 0;
}
/**
* irq_wake_thread - wake the irq thread for the action identified by dev_id
* @irq: Interrupt line
* @dev_id: Device identity for which the thread should be woken
*
*/
void irq_wake_thread(unsigned int irq, void *dev_id)
{
struct irq_desc *desc = irq_to_desc(irq);
struct irqaction *action;
unsigned long flags;
if (!desc || WARN_ON(irq_settings_is_per_cpu_devid(desc)))
return;
raw_spin_lock_irqsave(&desc->lock, flags);
for_each_action_of_desc(desc, action) {
if (action->dev_id == dev_id) {
if (action->thread)
__irq_wake_thread(desc, action);
break;
}
}
raw_spin_unlock_irqrestore(&desc->lock, flags);
}
EXPORT_SYMBOL_GPL(irq_wake_thread);
static int irq_setup_forced_threading(struct irqaction *new)
{
if (!force_irqthreads())
return 0;
if (new->flags & (IRQF_NO_THREAD | IRQF_PERCPU | IRQF_ONESHOT))
return 0;
/*
* No further action required for interrupts which are requested as
* threaded interrupts already
*/
if (new->handler == irq_default_primary_handler)
return 0;
new->flags |= IRQF_ONESHOT;
/*
* Handle the case where we have a real primary handler and a
* thread handler. We force thread them as well by creating a
* secondary action.
*/
if (new->handler && new->thread_fn) {
/* Allocate the secondary action */
new->secondary = kzalloc(sizeof(struct irqaction), GFP_KERNEL);
if (!new->secondary)
return -ENOMEM;
new->secondary->handler = irq_forced_secondary_handler;
new->secondary->thread_fn = new->thread_fn;
new->secondary->dev_id = new->dev_id;
new->secondary->irq = new->irq;
new->secondary->name = new->name;
}
/* Deal with the primary handler */
set_bit(IRQTF_FORCED_THREAD, &new->thread_flags);
new->thread_fn = new->handler;
new->handler = irq_default_primary_handler;
return 0;
}
static int irq_request_resources(struct irq_desc *desc)
{
struct irq_data *d = &desc->irq_data;
struct irq_chip *c = d->chip;
return c->irq_request_resources ? c->irq_request_resources(d) : 0;
}
static void irq_release_resources(struct irq_desc *desc)
{
struct irq_data *d = &desc->irq_data;
struct irq_chip *c = d->chip;
if (c->irq_release_resources)
c->irq_release_resources(d);
}
static bool irq_supports_nmi(struct irq_desc *desc)
{
struct irq_data *d = irq_desc_get_irq_data(desc);
#ifdef CONFIG_IRQ_DOMAIN_HIERARCHY
/* Only IRQs directly managed by the root irqchip can be set as NMI */
if (d->parent_data)
return false;
#endif
/* Don't support NMIs for chips behind a slow bus */
if (d->chip->irq_bus_lock || d->chip->irq_bus_sync_unlock)
return false;
return d->chip->flags & IRQCHIP_SUPPORTS_NMI;
}
static int irq_nmi_setup(struct irq_desc *desc)
{
struct irq_data *d = irq_desc_get_irq_data(desc);
struct irq_chip *c = d->chip;
return c->irq_nmi_setup ? c->irq_nmi_setup(d) : -EINVAL;
}
static void irq_nmi_teardown(struct irq_desc *desc)
{
struct irq_data *d = irq_desc_get_irq_data(desc);
struct irq_chip *c = d->chip;
if (c->irq_nmi_teardown)
c->irq_nmi_teardown(d);
}
static int
setup_irq_thread(struct irqaction *new, unsigned int irq, bool secondary)
{
struct task_struct *t;
if (!secondary) {
t = kthread_create(irq_thread, new, "irq/%d-%s", irq,
new->name);
} else {
t = kthread_create(irq_thread, new, "irq/%d-s-%s", irq,
new->name);
}
if (IS_ERR(t))
return PTR_ERR(t);
/*
* We keep the reference to the task struct even if
* the thread dies to avoid that the interrupt code
* references an already freed task_struct.
*/
new->thread = get_task_struct(t);
/*
* Tell the thread to set its affinity. This is
* important for shared interrupt handlers as we do
* not invoke setup_affinity() for the secondary
* handlers as everything is already set up. Even for
* interrupts marked with IRQF_NO_BALANCE this is
* correct as we want the thread to move to the cpu(s)
* on which the requesting code placed the interrupt.
*/
set_bit(IRQTF_AFFINITY, &new->thread_flags);
return 0;
}
/*
* Internal function to register an irqaction - typically used to
* allocate special interrupts that are part of the architecture.
*
* Locking rules:
*
* desc->request_mutex Provides serialization against a concurrent free_irq()
* chip_bus_lock Provides serialization for slow bus operations
* desc->lock Provides serialization against hard interrupts
*
* chip_bus_lock and desc->lock are sufficient for all other management and
* interrupt related functions. desc->request_mutex solely serializes
* request/free_irq().
*/
static int
__setup_irq(unsigned int irq, struct irq_desc *desc, struct irqaction *new)
{
struct irqaction *old, **old_ptr;
unsigned long flags, thread_mask = 0;
int ret, nested, shared = 0;
if (!desc)
return -EINVAL;
if (desc->irq_data.chip == &no_irq_chip)
return -ENOSYS;
if (!try_module_get(desc->owner))
return -ENODEV;
new->irq = irq;
/*
* If the trigger type is not specified by the caller,
* then use the default for this interrupt.
*/
if (!(new->flags & IRQF_TRIGGER_MASK))
new->flags |= irqd_get_trigger_type(&desc->irq_data);
/*
* Check whether the interrupt nests into another interrupt
* thread.
*/
nested = irq_settings_is_nested_thread(desc);
if (nested) {
if (!new->thread_fn) {
ret = -EINVAL;
goto out_mput;
}
/*
* Replace the primary handler which was provided from
* the driver for non nested interrupt handling by the
* dummy function which warns when called.
*/
new->handler = irq_nested_primary_handler;
} else {
if (irq_settings_can_thread(desc)) {
ret = irq_setup_forced_threading(new);
if (ret)
goto out_mput;
}
}
/*
* Create a handler thread when a thread function is supplied
* and the interrupt does not nest into another interrupt
* thread.
*/
if (new->thread_fn && !nested) {
ret = setup_irq_thread(new, irq, false);
if (ret)
goto out_mput;
if (new->secondary) {
ret = setup_irq_thread(new->secondary, irq, true);
if (ret)
goto out_thread;
}
}
/*
* Drivers are often written to work w/o knowledge about the
* underlying irq chip implementation, so a request for a
* threaded irq without a primary hard irq context handler
* requires the ONESHOT flag to be set. Some irq chips like
* MSI based interrupts are per se one shot safe. Check the
* chip flags, so we can avoid the unmask dance at the end of
* the threaded handler for those.
*/
if (desc->irq_data.chip->flags & IRQCHIP_ONESHOT_SAFE)
new->flags &= ~IRQF_ONESHOT;
/*
* Protects against a concurrent __free_irq() call which might wait
* for synchronize_hardirq() to complete without holding the optional
* chip bus lock and desc->lock. Also protects against handing out
* a recycled oneshot thread_mask bit while it's still in use by
* its previous owner.
*/
mutex_lock(&desc->request_mutex);
/*
* Acquire bus lock as the irq_request_resources() callback below
* might rely on the serialization or the magic power management
* functions which are abusing the irq_bus_lock() callback,
*/
chip_bus_lock(desc);
/* First installed action requests resources. */
if (!desc->action) {
ret = irq_request_resources(desc);
if (ret) {
pr_err("Failed to request resources for %s (irq %d) on irqchip %s\n",
new->name, irq, desc->irq_data.chip->name);
goto out_bus_unlock;
}
}
/*
* The following block of code has to be executed atomically
* protected against a concurrent interrupt and any of the other
* management calls which are not serialized via
* desc->request_mutex or the optional bus lock.
*/
raw_spin_lock_irqsave(&desc->lock, flags);
old_ptr = &desc->action;
old = *old_ptr;
if (old) {
/*
* Can't share interrupts unless both agree to and are
* the same type (level, edge, polarity). So both flag
* fields must have IRQF_SHARED set and the bits which
* set the trigger type must match. Also all must
* agree on ONESHOT.
* Interrupt lines used for NMIs cannot be shared.
*/
unsigned int oldtype;
if (desc->istate & IRQS_NMI) {
pr_err("Invalid attempt to share NMI for %s (irq %d) on irqchip %s.\n",
new->name, irq, desc->irq_data.chip->name);
ret = -EINVAL;
goto out_unlock;
}
/*
* If nobody did set the configuration before, inherit
* the one provided by the requester.
*/
if (irqd_trigger_type_was_set(&desc->irq_data)) {
oldtype = irqd_get_trigger_type(&desc->irq_data);
} else {
oldtype = new->flags & IRQF_TRIGGER_MASK;
irqd_set_trigger_type(&desc->irq_data, oldtype);
}
if (!((old->flags & new->flags) & IRQF_SHARED) ||
(oldtype != (new->flags & IRQF_TRIGGER_MASK)) ||
((old->flags ^ new->flags) & IRQF_ONESHOT))
goto mismatch;
/* All handlers must agree on per-cpuness */
if ((old->flags & IRQF_PERCPU) !=
(new->flags & IRQF_PERCPU))
goto mismatch;
/* add new interrupt at end of irq queue */
do {
/*
* Or all existing action->thread_mask bits,
* so we can find the next zero bit for this
* new action.
*/
thread_mask |= old->thread_mask;
old_ptr = &old->next;
old = *old_ptr;
} while (old);
shared = 1;
}
/*
* Setup the thread mask for this irqaction for ONESHOT. For
* !ONESHOT irqs the thread mask is 0 so we can avoid a
* conditional in irq_wake_thread().
*/
if (new->flags & IRQF_ONESHOT) {
/*
* Unlikely to have 32 resp 64 irqs sharing one line,
* but who knows.
*/
if (thread_mask == ~0UL) {
ret = -EBUSY;
goto out_unlock;
}
/*
* The thread_mask for the action is or'ed to
* desc->thread_active to indicate that the
* IRQF_ONESHOT thread handler has been woken, but not
* yet finished. The bit is cleared when a thread
* completes. When all threads of a shared interrupt
* line have completed desc->threads_active becomes
* zero and the interrupt line is unmasked. See
* handle.c:irq_wake_thread() for further information.
*
* If no thread is woken by primary (hard irq context)
* interrupt handlers, then desc->threads_active is
* also checked for zero to unmask the irq line in the
* affected hard irq flow handlers
* (handle_[fasteoi|level]_irq).
*
* The new action gets the first zero bit of
* thread_mask assigned. See the loop above which or's
* all existing action->thread_mask bits.
*/
new->thread_mask = 1UL << ffz(thread_mask);
} else if (new->handler == irq_default_primary_handler &&
!(desc->irq_data.chip->flags & IRQCHIP_ONESHOT_SAFE)) {
/*
* The interrupt was requested with handler = NULL, so
* we use the default primary handler for it. But it
* does not have the oneshot flag set. In combination
* with level interrupts this is deadly, because the
* default primary handler just wakes the thread, then
* the irq lines is reenabled, but the device still
* has the level irq asserted. Rinse and repeat....
*
* While this works for edge type interrupts, we play
* it safe and reject unconditionally because we can't
* say for sure which type this interrupt really
* has. The type flags are unreliable as the
* underlying chip implementation can override them.
*/
pr_err("Threaded irq requested with handler=NULL and !ONESHOT for %s (irq %d)\n",
new->name, irq);
ret = -EINVAL;
goto out_unlock;
}
if (!shared) {
/* Setup the type (level, edge polarity) if configured: */
if (new->flags & IRQF_TRIGGER_MASK) {
ret = __irq_set_trigger(desc,
new->flags & IRQF_TRIGGER_MASK);
if (ret)
goto out_unlock;
}
/*
* Activate the interrupt. That activation must happen
* independently of IRQ_NOAUTOEN. request_irq() can fail
* and the callers are supposed to handle
* that. enable_irq() of an interrupt requested with
* IRQ_NOAUTOEN is not supposed to fail. The activation
* keeps it in shutdown mode, it merily associates
* resources if necessary and if that's not possible it
* fails. Interrupts which are in managed shutdown mode
* will simply ignore that activation request.
*/
ret = irq_activate(desc);
if (ret)
goto out_unlock;
desc->istate &= ~(IRQS_AUTODETECT | IRQS_SPURIOUS_DISABLED | \
IRQS_ONESHOT | IRQS_WAITING);
irqd_clear(&desc->irq_data, IRQD_IRQ_INPROGRESS);
if (new->flags & IRQF_PERCPU) {
irqd_set(&desc->irq_data, IRQD_PER_CPU);
irq_settings_set_per_cpu(desc);
if (new->flags & IRQF_NO_DEBUG)
irq_settings_set_no_debug(desc);
}
if (noirqdebug)
irq_settings_set_no_debug(desc);
if (new->flags & IRQF_ONESHOT)
desc->istate |= IRQS_ONESHOT;
/* Exclude IRQ from balancing if requested */
if (new->flags & IRQF_NOBALANCING) {
irq_settings_set_no_balancing(desc);
irqd_set(&desc->irq_data, IRQD_NO_BALANCING);
}
if (!(new->flags & IRQF_NO_AUTOEN) &&
irq_settings_can_autoenable(desc)) {
irq_startup(desc, IRQ_RESEND, IRQ_START_COND);
} else {
/*
* Shared interrupts do not go well with disabling
* auto enable. The sharing interrupt might request
* it while it's still disabled and then wait for
* interrupts forever.
*/
WARN_ON_ONCE(new->flags & IRQF_SHARED);
/* Undo nested disables: */
desc->depth = 1;
}
} else if (new->flags & IRQF_TRIGGER_MASK) {
unsigned int nmsk = new->flags & IRQF_TRIGGER_MASK;
unsigned int omsk = irqd_get_trigger_type(&desc->irq_data);
if (nmsk != omsk)
/* hope the handler works with current trigger mode */
pr_warn("irq %d uses trigger mode %u; requested %u\n",
irq, omsk, nmsk);
}
*old_ptr = new;
irq_pm_install_action(desc, new);
/* Reset broken irq detection when installing new handler */
desc->irq_count = 0;
desc->irqs_unhandled = 0;
/*
* Check whether we disabled the irq via the spurious handler
* before. Reenable it and give it another chance.
*/
if (shared && (desc->istate & IRQS_SPURIOUS_DISABLED)) {
desc->istate &= ~IRQS_SPURIOUS_DISABLED;
__enable_irq(desc);
}
raw_spin_unlock_irqrestore(&desc->lock, flags);
chip_bus_sync_unlock(desc);
mutex_unlock(&desc->request_mutex);
irq_setup_timings(desc, new);
wake_up_and_wait_for_irq_thread_ready(desc, new);
wake_up_and_wait_for_irq_thread_ready(desc, new->secondary);
register_irq_proc(irq, desc);
new->dir = NULL;
register_handler_proc(irq, new);
return 0;
mismatch:
if (!(new->flags & IRQF_PROBE_SHARED)) {
pr_err("Flags mismatch irq %d. %08x (%s) vs. %08x (%s)\n",
irq, new->flags, new->name, old->flags, old->name);
#ifdef CONFIG_DEBUG_SHIRQ
dump_stack();
#endif
}
ret = -EBUSY;
out_unlock:
raw_spin_unlock_irqrestore(&desc->lock, flags);
if (!desc->action)
irq_release_resources(desc);
out_bus_unlock:
chip_bus_sync_unlock(desc);
mutex_unlock(&desc->request_mutex);
out_thread:
if (new->thread) {
struct task_struct *t = new->thread;
new->thread = NULL;
kthread_stop(t);
put_task_struct(t);
}
if (new->secondary && new->secondary->thread) {
struct task_struct *t = new->secondary->thread;
new->secondary->thread = NULL;
kthread_stop(t);
put_task_struct(t);
}
out_mput:
module_put(desc->owner);
return ret;
}
/*
* Internal function to unregister an irqaction - used to free
* regular and special interrupts that are part of the architecture.
*/
static struct irqaction *__free_irq(struct irq_desc *desc, void *dev_id)
{
unsigned irq = desc->irq_data.irq;
struct irqaction *action, **action_ptr;
unsigned long flags;
WARN(in_interrupt(), "Trying to free IRQ %d from IRQ context!\n", irq);
mutex_lock(&desc->request_mutex);
chip_bus_lock(desc);
raw_spin_lock_irqsave(&desc->lock, flags);
/*
* There can be multiple actions per IRQ descriptor, find the right
* one based on the dev_id:
*/
action_ptr = &desc->action;
for (;;) {
action = *action_ptr;
if (!action) {
WARN(1, "Trying to free already-free IRQ %d\n", irq);
raw_spin_unlock_irqrestore(&desc->lock, flags);
chip_bus_sync_unlock(desc);
mutex_unlock(&desc->request_mutex);
return NULL;
}
if (action->dev_id == dev_id)
break;
action_ptr = &action->next;
}
/* Found it - now remove it from the list of entries: */
*action_ptr = action->next;
irq_pm_remove_action(desc, action);
/* If this was the last handler, shut down the IRQ line: */
if (!desc->action) {
irq_settings_clr_disable_unlazy(desc);
/* Only shutdown. Deactivate after synchronize_hardirq() */
irq_shutdown(desc);
}
#ifdef CONFIG_SMP
/* make sure affinity_hint is cleaned up */
if (WARN_ON_ONCE(desc->affinity_hint))
desc->affinity_hint = NULL;
#endif
raw_spin_unlock_irqrestore(&desc->lock, flags);
/*
* Drop bus_lock here so the changes which were done in the chip
* callbacks above are synced out to the irq chips which hang
* behind a slow bus (I2C, SPI) before calling synchronize_hardirq().
*
* Aside of that the bus_lock can also be taken from the threaded
* handler in irq_finalize_oneshot() which results in a deadlock
* because kthread_stop() would wait forever for the thread to
* complete, which is blocked on the bus lock.
*
* The still held desc->request_mutex() protects against a
* concurrent request_irq() of this irq so the release of resources
* and timing data is properly serialized.
*/
chip_bus_sync_unlock(desc);
unregister_handler_proc(irq, action);
/*
* Make sure it's not being used on another CPU and if the chip
* supports it also make sure that there is no (not yet serviced)
* interrupt in flight at the hardware level.
*/
__synchronize_hardirq(desc, true);
#ifdef CONFIG_DEBUG_SHIRQ
/*
* It's a shared IRQ -- the driver ought to be prepared for an IRQ
* event to happen even now it's being freed, so let's make sure that
* is so by doing an extra call to the handler ....
*
* ( We do this after actually deregistering it, to make sure that a
* 'real' IRQ doesn't run in parallel with our fake. )
*/
if (action->flags & IRQF_SHARED) {
local_irq_save(flags);
action->handler(irq, dev_id);
local_irq_restore(flags);
}
#endif
/*
* The action has already been removed above, but the thread writes
* its oneshot mask bit when it completes. Though request_mutex is
* held across this which prevents __setup_irq() from handing out
* the same bit to a newly requested action.
*/
if (action->thread) {
kthread_stop(action->thread);
put_task_struct(action->thread);
if (action->secondary && action->secondary->thread) {
kthread_stop(action->secondary->thread);
put_task_struct(action->secondary->thread);
}
}
/* Last action releases resources */
if (!desc->action) {
/*
* Reacquire bus lock as irq_release_resources() might
* require it to deallocate resources over the slow bus.
*/
chip_bus_lock(desc);
/*
* There is no interrupt on the fly anymore. Deactivate it
* completely.
*/
raw_spin_lock_irqsave(&desc->lock, flags);
irq_domain_deactivate_irq(&desc->irq_data);
raw_spin_unlock_irqrestore(&desc->lock, flags);
irq_release_resources(desc);
chip_bus_sync_unlock(desc);
irq_remove_timings(desc);
}
mutex_unlock(&desc->request_mutex);
irq_chip_pm_put(&desc->irq_data);
module_put(desc->owner);
kfree(action->secondary);
return action;
}
/**
* free_irq - free an interrupt allocated with request_irq
* @irq: Interrupt line to free
* @dev_id: Device identity to free
*
* Remove an interrupt handler. The handler is removed and if the
* interrupt line is no longer in use by any driver it is disabled.
* On a shared IRQ the caller must ensure the interrupt is disabled
* on the card it drives before calling this function. The function
* does not return until any executing interrupts for this IRQ
* have completed.
*
* This function must not be called from interrupt context.
*
* Returns the devname argument passed to request_irq.
*/
const void *free_irq(unsigned int irq, void *dev_id)
{
struct irq_desc *desc = irq_to_desc(irq);
struct irqaction *action;
const char *devname;
if (!desc || WARN_ON(irq_settings_is_per_cpu_devid(desc)))
return NULL;
#ifdef CONFIG_SMP
if (WARN_ON(desc->affinity_notify))
desc->affinity_notify = NULL;
#endif
action = __free_irq(desc, dev_id);
if (!action)
return NULL;
devname = action->name;
kfree(action);
return devname;
}
EXPORT_SYMBOL(free_irq);
/* This function must be called with desc->lock held */
static const void *__cleanup_nmi(unsigned int irq, struct irq_desc *desc)
{
const char *devname = NULL;
desc->istate &= ~IRQS_NMI;
if (!WARN_ON(desc->action == NULL)) {
irq_pm_remove_action(desc, desc->action);
devname = desc->action->name;
unregister_handler_proc(irq, desc->action);
kfree(desc->action);
desc->action = NULL;
}
irq_settings_clr_disable_unlazy(desc);
irq_shutdown_and_deactivate(desc);
irq_release_resources(desc);
irq_chip_pm_put(&desc->irq_data);
module_put(desc->owner);
return devname;
}
const void *free_nmi(unsigned int irq, void *dev_id)
{
struct irq_desc *desc = irq_to_desc(irq);
unsigned long flags;
const void *devname;
if (!desc || WARN_ON(!(desc->istate & IRQS_NMI)))
return NULL;
if (WARN_ON(irq_settings_is_per_cpu_devid(desc)))
return NULL;
/* NMI still enabled */
if (WARN_ON(desc->depth == 0))
disable_nmi_nosync(irq);
raw_spin_lock_irqsave(&desc->lock, flags);
irq_nmi_teardown(desc);
devname = __cleanup_nmi(irq, desc);
raw_spin_unlock_irqrestore(&desc->lock, flags);
return devname;
}
/**
* request_threaded_irq - allocate an interrupt line
* @irq: Interrupt line to allocate
* @handler: Function to be called when the IRQ occurs.
* Primary handler for threaded interrupts.
* If handler is NULL and thread_fn != NULL
* the default primary handler is installed.
* @thread_fn: Function called from the irq handler thread
* If NULL, no irq thread is created
* @irqflags: Interrupt type flags
* @devname: An ascii name for the claiming device
* @dev_id: A cookie passed back to the handler function
*
* This call allocates interrupt resources and enables the
* interrupt line and IRQ handling. From the point this
* call is made your handler function may be invoked. Since
* your handler function must clear any interrupt the board
* raises, you must take care both to initialise your hardware
* and to set up the interrupt handler in the right order.
*
* If you want to set up a threaded irq handler for your device
* then you need to supply @handler and @thread_fn. @handler is
* still called in hard interrupt context and has to check
* whether the interrupt originates from the device. If yes it
* needs to disable the interrupt on the device and return
* IRQ_WAKE_THREAD which will wake up the handler thread and run
* @thread_fn. This split handler design is necessary to support
* shared interrupts.
*
* Dev_id must be globally unique. Normally the address of the
* device data structure is used as the cookie. Since the handler
* receives this value it makes sense to use it.
*
* If your interrupt is shared you must pass a non NULL dev_id
* as this is required when freeing the interrupt.
*
* Flags:
*
* IRQF_SHARED Interrupt is shared
* IRQF_TRIGGER_* Specify active edge(s) or level
* IRQF_ONESHOT Run thread_fn with interrupt line masked
*/
int request_threaded_irq(unsigned int irq, irq_handler_t handler,
irq_handler_t thread_fn, unsigned long irqflags,
const char *devname, void *dev_id)
{
struct irqaction *action;
struct irq_desc *desc;
int retval;
if (irq == IRQ_NOTCONNECTED)
return -ENOTCONN;
/*
* Sanity-check: shared interrupts must pass in a real dev-ID,
* otherwise we'll have trouble later trying to figure out
* which interrupt is which (messes up the interrupt freeing
* logic etc).
*
* Also shared interrupts do not go well with disabling auto enable.
* The sharing interrupt might request it while it's still disabled
* and then wait for interrupts forever.
*
* Also IRQF_COND_SUSPEND only makes sense for shared interrupts and
* it cannot be set along with IRQF_NO_SUSPEND.
*/
if (((irqflags & IRQF_SHARED) && !dev_id) ||
((irqflags & IRQF_SHARED) && (irqflags & IRQF_NO_AUTOEN)) ||
(!(irqflags & IRQF_SHARED) && (irqflags & IRQF_COND_SUSPEND)) ||
((irqflags & IRQF_NO_SUSPEND) && (irqflags & IRQF_COND_SUSPEND)))
return -EINVAL;
desc = irq_to_desc(irq);
if (!desc)
return -EINVAL;
if (!irq_settings_can_request(desc) ||
WARN_ON(irq_settings_is_per_cpu_devid(desc)))
return -EINVAL;
if (!handler) {
if (!thread_fn)
return -EINVAL;
handler = irq_default_primary_handler;
}
action = kzalloc(sizeof(struct irqaction), GFP_KERNEL);
if (!action)
return -ENOMEM;
action->handler = handler;
action->thread_fn = thread_fn;
action->flags = irqflags;
action->name = devname;
action->dev_id = dev_id;
retval = irq_chip_pm_get(&desc->irq_data);
if (retval < 0) {
kfree(action);
return retval;
}
retval = __setup_irq(irq, desc, action);
if (retval) {
irq_chip_pm_put(&desc->irq_data);
kfree(action->secondary);
kfree(action);
}
#ifdef CONFIG_DEBUG_SHIRQ_FIXME
if (!retval && (irqflags & IRQF_SHARED)) {
/*
* It's a shared IRQ -- the driver ought to be prepared for it
* to happen immediately, so let's make sure....
* We disable the irq to make sure that a 'real' IRQ doesn't
* run in parallel with our fake.
*/
unsigned long flags;
disable_irq(irq);
local_irq_save(flags);
handler(irq, dev_id);
local_irq_restore(flags);
enable_irq(irq);
}
#endif
return retval;
}
EXPORT_SYMBOL(request_threaded_irq);
/**
* request_any_context_irq - allocate an interrupt line
* @irq: Interrupt line to allocate
* @handler: Function to be called when the IRQ occurs.
* Threaded handler for threaded interrupts.
* @flags: Interrupt type flags
* @name: An ascii name for the claiming device
* @dev_id: A cookie passed back to the handler function
*
* This call allocates interrupt resources and enables the
* interrupt line and IRQ handling. It selects either a
* hardirq or threaded handling method depending on the
* context.
*
* On failure, it returns a negative value. On success,
* it returns either IRQC_IS_HARDIRQ or IRQC_IS_NESTED.
*/
int request_any_context_irq(unsigned int irq, irq_handler_t handler,
unsigned long flags, const char *name, void *dev_id)
{
struct irq_desc *desc;
int ret;
if (irq == IRQ_NOTCONNECTED)
return -ENOTCONN;
desc = irq_to_desc(irq);
if (!desc)
return -EINVAL;
if (irq_settings_is_nested_thread(desc)) {
ret = request_threaded_irq(irq, NULL, handler,
flags, name, dev_id);
return !ret ? IRQC_IS_NESTED : ret;
}
ret = request_irq(irq, handler, flags, name, dev_id);
return !ret ? IRQC_IS_HARDIRQ : ret;
}
EXPORT_SYMBOL_GPL(request_any_context_irq);
/**
* request_nmi - allocate an interrupt line for NMI delivery
* @irq: Interrupt line to allocate
* @handler: Function to be called when the IRQ occurs.
* Threaded handler for threaded interrupts.
* @irqflags: Interrupt type flags
* @name: An ascii name for the claiming device
* @dev_id: A cookie passed back to the handler function
*
* This call allocates interrupt resources and enables the
* interrupt line and IRQ handling. It sets up the IRQ line
* to be handled as an NMI.
*
* An interrupt line delivering NMIs cannot be shared and IRQ handling
* cannot be threaded.
*
* Interrupt lines requested for NMI delivering must produce per cpu
* interrupts and have auto enabling setting disabled.
*
* Dev_id must be globally unique. Normally the address of the
* device data structure is used as the cookie. Since the handler
* receives this value it makes sense to use it.
*
* If the interrupt line cannot be used to deliver NMIs, function
* will fail and return a negative value.
*/
int request_nmi(unsigned int irq, irq_handler_t handler,
unsigned long irqflags, const char *name, void *dev_id)
{
struct irqaction *action;
struct irq_desc *desc;
unsigned long flags;
int retval;
if (irq == IRQ_NOTCONNECTED)
return -ENOTCONN;
/* NMI cannot be shared, used for Polling */
if (irqflags & (IRQF_SHARED | IRQF_COND_SUSPEND | IRQF_IRQPOLL))
return -EINVAL;
if (!(irqflags & IRQF_PERCPU))
return -EINVAL;
if (!handler)
return -EINVAL;
desc = irq_to_desc(irq);
if (!desc || (irq_settings_can_autoenable(desc) &&
!(irqflags & IRQF_NO_AUTOEN)) ||
!irq_settings_can_request(desc) ||
WARN_ON(irq_settings_is_per_cpu_devid(desc)) ||
!irq_supports_nmi(desc))
return -EINVAL;
action = kzalloc(sizeof(struct irqaction), GFP_KERNEL);
if (!action)
return -ENOMEM;
action->handler = handler;
action->flags = irqflags | IRQF_NO_THREAD | IRQF_NOBALANCING;
action->name = name;
action->dev_id = dev_id;
retval = irq_chip_pm_get(&desc->irq_data);
if (retval < 0)
goto err_out;
retval = __setup_irq(irq, desc, action);
if (retval)
goto err_irq_setup;
raw_spin_lock_irqsave(&desc->lock, flags);
/* Setup NMI state */
desc->istate |= IRQS_NMI;
retval = irq_nmi_setup(desc);
if (retval) {
__cleanup_nmi(irq, desc);
raw_spin_unlock_irqrestore(&desc->lock, flags);
return -EINVAL;
}
raw_spin_unlock_irqrestore(&desc->lock, flags);
return 0;
err_irq_setup:
irq_chip_pm_put(&desc->irq_data);
err_out:
kfree(action);
return retval;
}
void enable_percpu_irq(unsigned int irq, unsigned int type)
{
unsigned int cpu = smp_processor_id();
unsigned long flags;
struct irq_desc *desc = irq_get_desc_lock(irq, &flags, IRQ_GET_DESC_CHECK_PERCPU);
if (!desc)
return;
/*
* If the trigger type is not specified by the caller, then
* use the default for this interrupt.
*/
type &= IRQ_TYPE_SENSE_MASK;
if (type == IRQ_TYPE_NONE)
type = irqd_get_trigger_type(&desc->irq_data);
if (type != IRQ_TYPE_NONE) {
int ret;
ret = __irq_set_trigger(desc, type);
if (ret) {
WARN(1, "failed to set type for IRQ%d\n", irq);
goto out;
}
}
irq_percpu_enable(desc, cpu);
out:
irq_put_desc_unlock(desc, flags);
}
EXPORT_SYMBOL_GPL(enable_percpu_irq);
void enable_percpu_nmi(unsigned int irq, unsigned int type)
{
enable_percpu_irq(irq, type);
}
/**
* irq_percpu_is_enabled - Check whether the per cpu irq is enabled
* @irq: Linux irq number to check for
*
* Must be called from a non migratable context. Returns the enable
* state of a per cpu interrupt on the current cpu.
*/
bool irq_percpu_is_enabled(unsigned int irq)
{
unsigned int cpu = smp_processor_id();
struct irq_desc *desc;
unsigned long flags;
bool is_enabled;
desc = irq_get_desc_lock(irq, &flags, IRQ_GET_DESC_CHECK_PERCPU);
if (!desc)
return false;
is_enabled = cpumask_test_cpu(cpu, desc->percpu_enabled);
irq_put_desc_unlock(desc, flags);
return is_enabled;
}
EXPORT_SYMBOL_GPL(irq_percpu_is_enabled);
void disable_percpu_irq(unsigned int irq)
{
unsigned int cpu = smp_processor_id();
unsigned long flags;
struct irq_desc *desc = irq_get_desc_lock(irq, &flags, IRQ_GET_DESC_CHECK_PERCPU);
if (!desc)
return;
irq_percpu_disable(desc, cpu);
irq_put_desc_unlock(desc, flags);
}
EXPORT_SYMBOL_GPL(disable_percpu_irq);
void disable_percpu_nmi(unsigned int irq)
{
disable_percpu_irq(irq);
}
/*
* Internal function to unregister a percpu irqaction.
*/
static struct irqaction *__free_percpu_irq(unsigned int irq, void __percpu *dev_id)
{
struct irq_desc *desc = irq_to_desc(irq);
struct irqaction *action;
unsigned long flags;
WARN(in_interrupt(), "Trying to free IRQ %d from IRQ context!\n", irq);
if (!desc)
return NULL;
raw_spin_lock_irqsave(&desc->lock, flags);
action = desc->action;
if (!action || action->percpu_dev_id != dev_id) {
WARN(1, "Trying to free already-free IRQ %d\n", irq);
goto bad;
}
if (!cpumask_empty(desc->percpu_enabled)) {
WARN(1, "percpu IRQ %d still enabled on CPU%d!\n",
irq, cpumask_first(desc->percpu_enabled));
goto bad;
}
/* Found it - now remove it from the list of entries: */
desc->action = NULL;
desc->istate &= ~IRQS_NMI;
raw_spin_unlock_irqrestore(&desc->lock, flags);
unregister_handler_proc(irq, action);
irq_chip_pm_put(&desc->irq_data);
module_put(desc->owner);
return action;
bad:
raw_spin_unlock_irqrestore(&desc->lock, flags);
return NULL;
}
/**
* remove_percpu_irq - free a per-cpu interrupt
* @irq: Interrupt line to free
* @act: irqaction for the interrupt
*
* Used to remove interrupts statically setup by the early boot process.
*/
void remove_percpu_irq(unsigned int irq, struct irqaction *act)
{
struct irq_desc *desc = irq_to_desc(irq);
if (desc && irq_settings_is_per_cpu_devid(desc))
__free_percpu_irq(irq, act->percpu_dev_id);
}
/**
* free_percpu_irq - free an interrupt allocated with request_percpu_irq
* @irq: Interrupt line to free
* @dev_id: Device identity to free
*
* Remove a percpu interrupt handler. The handler is removed, but
* the interrupt line is not disabled. This must be done on each
* CPU before calling this function. The function does not return
* until any executing interrupts for this IRQ have completed.
*
* This function must not be called from interrupt context.
*/
void free_percpu_irq(unsigned int irq, void __percpu *dev_id)
{
struct irq_desc *desc = irq_to_desc(irq);
if (!desc || !irq_settings_is_per_cpu_devid(desc))
return;
chip_bus_lock(desc);
kfree(__free_percpu_irq(irq, dev_id));
chip_bus_sync_unlock(desc);
}
EXPORT_SYMBOL_GPL(free_percpu_irq);
void free_percpu_nmi(unsigned int irq, void __percpu *dev_id)
{
struct irq_desc *desc = irq_to_desc(irq);
if (!desc || !irq_settings_is_per_cpu_devid(desc))
return;
if (WARN_ON(!(desc->istate & IRQS_NMI)))
return;
kfree(__free_percpu_irq(irq, dev_id));
}
/**
* setup_percpu_irq - setup a per-cpu interrupt
* @irq: Interrupt line to setup
* @act: irqaction for the interrupt
*
* Used to statically setup per-cpu interrupts in the early boot process.
*/
int setup_percpu_irq(unsigned int irq, struct irqaction *act)
{
struct irq_desc *desc = irq_to_desc(irq);
int retval;
if (!desc || !irq_settings_is_per_cpu_devid(desc))
return -EINVAL;
retval = irq_chip_pm_get(&desc->irq_data);
if (retval < 0)
return retval;
retval = __setup_irq(irq, desc, act);
if (retval)
irq_chip_pm_put(&desc->irq_data);
return retval;
}
/**
* __request_percpu_irq - allocate a percpu interrupt line
* @irq: Interrupt line to allocate
* @handler: Function to be called when the IRQ occurs.
* @flags: Interrupt type flags (IRQF_TIMER only)
* @devname: An ascii name for the claiming device
* @dev_id: A percpu cookie passed back to the handler function
*
* This call allocates interrupt resources and enables the
* interrupt on the local CPU. If the interrupt is supposed to be
* enabled on other CPUs, it has to be done on each CPU using
* enable_percpu_irq().
*
* Dev_id must be globally unique. It is a per-cpu variable, and
* the handler gets called with the interrupted CPU's instance of
* that variable.
*/
int __request_percpu_irq(unsigned int irq, irq_handler_t handler,
unsigned long flags, const char *devname,
void __percpu *dev_id)
{
struct irqaction *action;
struct irq_desc *desc;
int retval;
if (!dev_id)
return -EINVAL;
desc = irq_to_desc(irq);
if (!desc || !irq_settings_can_request(desc) ||
!irq_settings_is_per_cpu_devid(desc))
return -EINVAL;
if (flags && flags != IRQF_TIMER)
return -EINVAL;
action = kzalloc(sizeof(struct irqaction), GFP_KERNEL);
if (!action)
return -ENOMEM;
action->handler = handler;
action->flags = flags | IRQF_PERCPU | IRQF_NO_SUSPEND;
action->name = devname;
action->percpu_dev_id = dev_id;
retval = irq_chip_pm_get(&desc->irq_data);
if (retval < 0) {
kfree(action);
return retval;
}
retval = __setup_irq(irq, desc, action);
if (retval) {
irq_chip_pm_put(&desc->irq_data);
kfree(action);
}
return retval;
}
EXPORT_SYMBOL_GPL(__request_percpu_irq);
/**
* request_percpu_nmi - allocate a percpu interrupt line for NMI delivery
* @irq: Interrupt line to allocate
* @handler: Function to be called when the IRQ occurs.
* @name: An ascii name for the claiming device
* @dev_id: A percpu cookie passed back to the handler function
*
* This call allocates interrupt resources for a per CPU NMI. Per CPU NMIs
* have to be setup on each CPU by calling prepare_percpu_nmi() before
* being enabled on the same CPU by using enable_percpu_nmi().
*
* Dev_id must be globally unique. It is a per-cpu variable, and
* the handler gets called with the interrupted CPU's instance of
* that variable.
*
* Interrupt lines requested for NMI delivering should have auto enabling
* setting disabled.
*
* If the interrupt line cannot be used to deliver NMIs, function
* will fail returning a negative value.
*/
int request_percpu_nmi(unsigned int irq, irq_handler_t handler,
const char *name, void __percpu *dev_id)
{
struct irqaction *action;
struct irq_desc *desc;
unsigned long flags;
int retval;
if (!handler)
return -EINVAL;
desc = irq_to_desc(irq);
if (!desc || !irq_settings_can_request(desc) ||
!irq_settings_is_per_cpu_devid(desc) ||
irq_settings_can_autoenable(desc) ||
!irq_supports_nmi(desc))
return -EINVAL;
/* The line cannot already be NMI */
if (desc->istate & IRQS_NMI)
return -EINVAL;
action = kzalloc(sizeof(struct irqaction), GFP_KERNEL);
if (!action)
return -ENOMEM;
action->handler = handler;
action->flags = IRQF_PERCPU | IRQF_NO_SUSPEND | IRQF_NO_THREAD
| IRQF_NOBALANCING;
action->name = name;
action->percpu_dev_id = dev_id;
retval = irq_chip_pm_get(&desc->irq_data);
if (retval < 0)
goto err_out;
retval = __setup_irq(irq, desc, action);
if (retval)
goto err_irq_setup;
raw_spin_lock_irqsave(&desc->lock, flags);
desc->istate |= IRQS_NMI;
raw_spin_unlock_irqrestore(&desc->lock, flags);
return 0;
err_irq_setup:
irq_chip_pm_put(&desc->irq_data);
err_out:
kfree(action);
return retval;
}
/**
* prepare_percpu_nmi - performs CPU local setup for NMI delivery
* @irq: Interrupt line to prepare for NMI delivery
*
* This call prepares an interrupt line to deliver NMI on the current CPU,
* before that interrupt line gets enabled with enable_percpu_nmi().
*
* As a CPU local operation, this should be called from non-preemptible
* context.
*
* If the interrupt line cannot be used to deliver NMIs, function
* will fail returning a negative value.
*/
int prepare_percpu_nmi(unsigned int irq)
{
unsigned long flags;
struct irq_desc *desc;
int ret = 0;
WARN_ON(preemptible());
desc = irq_get_desc_lock(irq, &flags,
IRQ_GET_DESC_CHECK_PERCPU);
if (!desc)
return -EINVAL;
if (WARN(!(desc->istate & IRQS_NMI),
KERN_ERR "prepare_percpu_nmi called for a non-NMI interrupt: irq %u\n",
irq)) {
ret = -EINVAL;
goto out;
}
ret = irq_nmi_setup(desc);
if (ret) {
pr_err("Failed to setup NMI delivery: irq %u\n", irq);
goto out;
}
out:
irq_put_desc_unlock(desc, flags);
return ret;
}
/**
* teardown_percpu_nmi - undoes NMI setup of IRQ line
* @irq: Interrupt line from which CPU local NMI configuration should be
* removed
*
* This call undoes the setup done by prepare_percpu_nmi().
*
* IRQ line should not be enabled for the current CPU.
*
* As a CPU local operation, this should be called from non-preemptible
* context.
*/
void teardown_percpu_nmi(unsigned int irq)
{
unsigned long flags;
struct irq_desc *desc;
WARN_ON(preemptible());
desc = irq_get_desc_lock(irq, &flags,
IRQ_GET_DESC_CHECK_PERCPU);
if (!desc)
return;
if (WARN_ON(!(desc->istate & IRQS_NMI)))
goto out;
irq_nmi_teardown(desc);
out:
irq_put_desc_unlock(desc, flags);
}
int __irq_get_irqchip_state(struct irq_data *data, enum irqchip_irq_state which,
bool *state)
{
struct irq_chip *chip;
int err = -EINVAL;
do {
chip = irq_data_get_irq_chip(data);
if (WARN_ON_ONCE(!chip))
return -ENODEV;
if (chip->irq_get_irqchip_state)
break;
#ifdef CONFIG_IRQ_DOMAIN_HIERARCHY
data = data->parent_data;
#else
data = NULL;
#endif
} while (data);
if (data)
err = chip->irq_get_irqchip_state(data, which, state);
return err;
}
/**
* irq_get_irqchip_state - returns the irqchip state of a interrupt.
* @irq: Interrupt line that is forwarded to a VM
* @which: One of IRQCHIP_STATE_* the caller wants to know about
* @state: a pointer to a boolean where the state is to be stored
*
* This call snapshots the internal irqchip state of an
* interrupt, returning into @state the bit corresponding to
* stage @which
*
* This function should be called with preemption disabled if the
* interrupt controller has per-cpu registers.
*/
int irq_get_irqchip_state(unsigned int irq, enum irqchip_irq_state which,
bool *state)
{
struct irq_desc *desc;
struct irq_data *data;
unsigned long flags;
int err = -EINVAL;
desc = irq_get_desc_buslock(irq, &flags, 0);
if (!desc)
return err;
data = irq_desc_get_irq_data(desc);
err = __irq_get_irqchip_state(data, which, state);
irq_put_desc_busunlock(desc, flags);
return err;
}
EXPORT_SYMBOL_GPL(irq_get_irqchip_state);
/**
* irq_set_irqchip_state - set the state of a forwarded interrupt.
* @irq: Interrupt line that is forwarded to a VM
* @which: State to be restored (one of IRQCHIP_STATE_*)
* @val: Value corresponding to @which
*
* This call sets the internal irqchip state of an interrupt,
* depending on the value of @which.
*
* This function should be called with migration disabled if the
* interrupt controller has per-cpu registers.
*/
int irq_set_irqchip_state(unsigned int irq, enum irqchip_irq_state which,
bool val)
{
struct irq_desc *desc;
struct irq_data *data;
struct irq_chip *chip;
unsigned long flags;
int err = -EINVAL;
desc = irq_get_desc_buslock(irq, &flags, 0);
if (!desc)
return err;
data = irq_desc_get_irq_data(desc);
do {
chip = irq_data_get_irq_chip(data);
if (WARN_ON_ONCE(!chip)) {
err = -ENODEV;
goto out_unlock;
}
if (chip->irq_set_irqchip_state)
break;
#ifdef CONFIG_IRQ_DOMAIN_HIERARCHY
data = data->parent_data;
#else
data = NULL;
#endif
} while (data);
if (data)
err = chip->irq_set_irqchip_state(data, which, val);
out_unlock:
irq_put_desc_busunlock(desc, flags);
return err;
}
EXPORT_SYMBOL_GPL(irq_set_irqchip_state);
/**
* irq_has_action - Check whether an interrupt is requested
* @irq: The linux irq number
*
* Returns: A snapshot of the current state
*/
bool irq_has_action(unsigned int irq)
{
bool res;
rcu_read_lock();
res = irq_desc_has_action(irq_to_desc(irq));
rcu_read_unlock();
return res;
}
EXPORT_SYMBOL_GPL(irq_has_action);
/**
* irq_check_status_bit - Check whether bits in the irq descriptor status are set
* @irq: The linux irq number
* @bitmask: The bitmask to evaluate
*
* Returns: True if one of the bits in @bitmask is set
*/
bool irq_check_status_bit(unsigned int irq, unsigned int bitmask)
{
struct irq_desc *desc;
bool res = false;
rcu_read_lock();
desc = irq_to_desc(irq);
if (desc)
res = !!(desc->status_use_accessors & bitmask);
rcu_read_unlock();
return res;
}
EXPORT_SYMBOL_GPL(irq_check_status_bit);