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![Alan Cox](/assets/img/avatar_default.png)
The array check is useless so remove it. [akpm@linux-foundation.org: remove comment, per David] Signed-off-by: Alan Cox <alan@linux.intel.com> Cc: David Rientjes <rientjes@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
1691 lines
43 KiB
C
1691 lines
43 KiB
C
/*
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* linux/kernel/irq/manage.c
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*
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* Copyright (C) 1992, 1998-2006 Linus Torvalds, Ingo Molnar
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* Copyright (C) 2005-2006 Thomas Gleixner
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*
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* This file contains driver APIs to the irq subsystem.
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*/
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#define pr_fmt(fmt) "genirq: " fmt
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#include <linux/irq.h>
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#include <linux/kthread.h>
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#include <linux/module.h>
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#include <linux/random.h>
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#include <linux/interrupt.h>
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#include <linux/slab.h>
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#include <linux/sched.h>
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#include <linux/task_work.h>
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#include "internals.h"
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#ifdef CONFIG_IRQ_FORCED_THREADING
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__read_mostly bool force_irqthreads;
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static int __init setup_forced_irqthreads(char *arg)
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{
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force_irqthreads = true;
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return 0;
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}
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early_param("threadirqs", setup_forced_irqthreads);
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#endif
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/**
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* synchronize_irq - wait for pending IRQ handlers (on other CPUs)
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* @irq: interrupt number to wait for
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*
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* This function waits for any pending IRQ handlers for this interrupt
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* to complete before returning. If you use this function while
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* holding a resource the IRQ handler may need you will deadlock.
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*
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* This function may be called - with care - from IRQ context.
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*/
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void synchronize_irq(unsigned int irq)
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{
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struct irq_desc *desc = irq_to_desc(irq);
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bool inprogress;
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if (!desc)
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return;
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do {
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unsigned long flags;
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/*
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* Wait until we're out of the critical section. This might
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* give the wrong answer due to the lack of memory barriers.
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*/
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while (irqd_irq_inprogress(&desc->irq_data))
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cpu_relax();
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/* Ok, that indicated we're done: double-check carefully. */
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raw_spin_lock_irqsave(&desc->lock, flags);
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inprogress = irqd_irq_inprogress(&desc->irq_data);
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raw_spin_unlock_irqrestore(&desc->lock, flags);
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/* Oops, that failed? */
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} while (inprogress);
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/*
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* We made sure that no hardirq handler is running. Now verify
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* that no threaded handlers are active.
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*/
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wait_event(desc->wait_for_threads, !atomic_read(&desc->threads_active));
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}
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EXPORT_SYMBOL(synchronize_irq);
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#ifdef CONFIG_SMP
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cpumask_var_t irq_default_affinity;
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/**
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* irq_can_set_affinity - Check if the affinity of a given irq can be set
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* @irq: Interrupt to check
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*
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*/
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int irq_can_set_affinity(unsigned int irq)
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{
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struct irq_desc *desc = irq_to_desc(irq);
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if (!desc || !irqd_can_balance(&desc->irq_data) ||
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!desc->irq_data.chip || !desc->irq_data.chip->irq_set_affinity)
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return 0;
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return 1;
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}
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/**
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* irq_set_thread_affinity - Notify irq threads to adjust affinity
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* @desc: irq descriptor which has affitnity changed
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*
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* We just set IRQTF_AFFINITY and delegate the affinity setting
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* to the interrupt thread itself. We can not call
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* set_cpus_allowed_ptr() here as we hold desc->lock and this
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* code can be called from hard interrupt context.
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*/
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void irq_set_thread_affinity(struct irq_desc *desc)
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{
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struct irqaction *action = desc->action;
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while (action) {
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if (action->thread)
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set_bit(IRQTF_AFFINITY, &action->thread_flags);
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action = action->next;
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}
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}
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#ifdef CONFIG_GENERIC_PENDING_IRQ
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static inline bool irq_can_move_pcntxt(struct irq_data *data)
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{
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return irqd_can_move_in_process_context(data);
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}
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static inline bool irq_move_pending(struct irq_data *data)
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{
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return irqd_is_setaffinity_pending(data);
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}
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static inline void
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irq_copy_pending(struct irq_desc *desc, const struct cpumask *mask)
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{
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cpumask_copy(desc->pending_mask, mask);
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}
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static inline void
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irq_get_pending(struct cpumask *mask, struct irq_desc *desc)
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{
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cpumask_copy(mask, desc->pending_mask);
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}
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#else
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static inline bool irq_can_move_pcntxt(struct irq_data *data) { return true; }
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static inline bool irq_move_pending(struct irq_data *data) { return false; }
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static inline void
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irq_copy_pending(struct irq_desc *desc, const struct cpumask *mask) { }
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static inline void
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irq_get_pending(struct cpumask *mask, struct irq_desc *desc) { }
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#endif
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int irq_do_set_affinity(struct irq_data *data, const struct cpumask *mask,
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bool force)
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{
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struct irq_desc *desc = irq_data_to_desc(data);
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struct irq_chip *chip = irq_data_get_irq_chip(data);
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int ret;
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ret = chip->irq_set_affinity(data, mask, false);
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switch (ret) {
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case IRQ_SET_MASK_OK:
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cpumask_copy(data->affinity, mask);
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case IRQ_SET_MASK_OK_NOCOPY:
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irq_set_thread_affinity(desc);
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ret = 0;
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}
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return ret;
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}
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int __irq_set_affinity_locked(struct irq_data *data, const struct cpumask *mask)
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{
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struct irq_chip *chip = irq_data_get_irq_chip(data);
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struct irq_desc *desc = irq_data_to_desc(data);
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int ret = 0;
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if (!chip || !chip->irq_set_affinity)
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return -EINVAL;
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if (irq_can_move_pcntxt(data)) {
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ret = irq_do_set_affinity(data, mask, false);
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} else {
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irqd_set_move_pending(data);
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irq_copy_pending(desc, mask);
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}
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if (desc->affinity_notify) {
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kref_get(&desc->affinity_notify->kref);
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schedule_work(&desc->affinity_notify->work);
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}
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irqd_set(data, IRQD_AFFINITY_SET);
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return ret;
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}
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/**
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* irq_set_affinity - Set the irq affinity of a given irq
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* @irq: Interrupt to set affinity
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* @mask: cpumask
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*
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*/
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int irq_set_affinity(unsigned int irq, const struct cpumask *mask)
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{
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struct irq_desc *desc = irq_to_desc(irq);
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unsigned long flags;
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int ret;
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if (!desc)
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return -EINVAL;
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raw_spin_lock_irqsave(&desc->lock, flags);
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ret = __irq_set_affinity_locked(irq_desc_get_irq_data(desc), mask);
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raw_spin_unlock_irqrestore(&desc->lock, flags);
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return ret;
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}
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int irq_set_affinity_hint(unsigned int irq, const struct cpumask *m)
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{
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unsigned long flags;
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struct irq_desc *desc = irq_get_desc_lock(irq, &flags, IRQ_GET_DESC_CHECK_GLOBAL);
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if (!desc)
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return -EINVAL;
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desc->affinity_hint = m;
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irq_put_desc_unlock(desc, flags);
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return 0;
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}
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EXPORT_SYMBOL_GPL(irq_set_affinity_hint);
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static void irq_affinity_notify(struct work_struct *work)
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{
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struct irq_affinity_notify *notify =
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container_of(work, struct irq_affinity_notify, work);
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struct irq_desc *desc = irq_to_desc(notify->irq);
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cpumask_var_t cpumask;
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unsigned long flags;
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if (!desc || !alloc_cpumask_var(&cpumask, GFP_KERNEL))
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goto out;
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raw_spin_lock_irqsave(&desc->lock, flags);
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if (irq_move_pending(&desc->irq_data))
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irq_get_pending(cpumask, desc);
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else
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cpumask_copy(cpumask, desc->irq_data.affinity);
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raw_spin_unlock_irqrestore(&desc->lock, flags);
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notify->notify(notify, cpumask);
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free_cpumask_var(cpumask);
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out:
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kref_put(¬ify->kref, notify->release);
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}
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/**
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* irq_set_affinity_notifier - control notification of IRQ affinity changes
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* @irq: Interrupt for which to enable/disable notification
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* @notify: Context for notification, or %NULL to disable
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* notification. Function pointers must be initialised;
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* the other fields will be initialised by this function.
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*
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* Must be called in process context. Notification may only be enabled
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* after the IRQ is allocated and must be disabled before the IRQ is
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* freed using free_irq().
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*/
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int
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irq_set_affinity_notifier(unsigned int irq, struct irq_affinity_notify *notify)
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{
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struct irq_desc *desc = irq_to_desc(irq);
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struct irq_affinity_notify *old_notify;
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unsigned long flags;
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/* The release function is promised process context */
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might_sleep();
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if (!desc)
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return -EINVAL;
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/* Complete initialisation of *notify */
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if (notify) {
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notify->irq = irq;
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kref_init(¬ify->kref);
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INIT_WORK(¬ify->work, irq_affinity_notify);
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}
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raw_spin_lock_irqsave(&desc->lock, flags);
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old_notify = desc->affinity_notify;
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desc->affinity_notify = notify;
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raw_spin_unlock_irqrestore(&desc->lock, flags);
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if (old_notify)
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kref_put(&old_notify->kref, old_notify->release);
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return 0;
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}
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EXPORT_SYMBOL_GPL(irq_set_affinity_notifier);
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#ifndef CONFIG_AUTO_IRQ_AFFINITY
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/*
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* Generic version of the affinity autoselector.
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*/
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static int
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setup_affinity(unsigned int irq, struct irq_desc *desc, struct cpumask *mask)
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{
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struct cpumask *set = irq_default_affinity;
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int node = desc->irq_data.node;
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/* Excludes PER_CPU and NO_BALANCE interrupts */
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if (!irq_can_set_affinity(irq))
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return 0;
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/*
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* Preserve an userspace affinity setup, but make sure that
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* one of the targets is online.
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*/
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if (irqd_has_set(&desc->irq_data, IRQD_AFFINITY_SET)) {
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if (cpumask_intersects(desc->irq_data.affinity,
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cpu_online_mask))
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set = desc->irq_data.affinity;
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else
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irqd_clear(&desc->irq_data, IRQD_AFFINITY_SET);
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}
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cpumask_and(mask, cpu_online_mask, set);
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if (node != NUMA_NO_NODE) {
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const struct cpumask *nodemask = cpumask_of_node(node);
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/* make sure at least one of the cpus in nodemask is online */
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if (cpumask_intersects(mask, nodemask))
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cpumask_and(mask, mask, nodemask);
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}
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irq_do_set_affinity(&desc->irq_data, mask, false);
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return 0;
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}
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#else
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static inline int
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setup_affinity(unsigned int irq, struct irq_desc *d, struct cpumask *mask)
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{
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return irq_select_affinity(irq);
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}
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#endif
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/*
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* Called when affinity is set via /proc/irq
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*/
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int irq_select_affinity_usr(unsigned int irq, struct cpumask *mask)
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{
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struct irq_desc *desc = irq_to_desc(irq);
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unsigned long flags;
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int ret;
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raw_spin_lock_irqsave(&desc->lock, flags);
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ret = setup_affinity(irq, desc, mask);
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raw_spin_unlock_irqrestore(&desc->lock, flags);
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return ret;
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}
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#else
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static inline int
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setup_affinity(unsigned int irq, struct irq_desc *desc, struct cpumask *mask)
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{
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return 0;
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}
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#endif
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void __disable_irq(struct irq_desc *desc, unsigned int irq, bool suspend)
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{
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if (suspend) {
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if (!desc->action || (desc->action->flags & IRQF_NO_SUSPEND))
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return;
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desc->istate |= IRQS_SUSPENDED;
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}
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if (!desc->depth++)
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irq_disable(desc);
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}
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static int __disable_irq_nosync(unsigned int irq)
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{
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unsigned long flags;
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struct irq_desc *desc = irq_get_desc_buslock(irq, &flags, IRQ_GET_DESC_CHECK_GLOBAL);
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if (!desc)
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return -EINVAL;
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__disable_irq(desc, irq, false);
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irq_put_desc_busunlock(desc, flags);
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return 0;
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}
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/**
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* disable_irq_nosync - disable an irq without waiting
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* @irq: Interrupt to disable
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*
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* Disable the selected interrupt line. Disables and Enables are
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* nested.
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* Unlike disable_irq(), this function does not ensure existing
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* instances of the IRQ handler have completed before returning.
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*
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* This function may be called from IRQ context.
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*/
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void disable_irq_nosync(unsigned int irq)
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{
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__disable_irq_nosync(irq);
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}
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EXPORT_SYMBOL(disable_irq_nosync);
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/**
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* disable_irq - disable an irq and wait for completion
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* @irq: Interrupt to disable
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*
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* Disable the selected interrupt line. Enables and Disables are
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* nested.
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* This function waits for any pending IRQ handlers for this interrupt
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* to complete before returning. If you use this function while
|
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* holding a resource the IRQ handler may need you will deadlock.
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*
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* This function may be called - with care - from IRQ context.
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*/
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void disable_irq(unsigned int irq)
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{
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if (!__disable_irq_nosync(irq))
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synchronize_irq(irq);
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}
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EXPORT_SYMBOL(disable_irq);
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void __enable_irq(struct irq_desc *desc, unsigned int irq, bool resume)
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{
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if (resume) {
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if (!(desc->istate & IRQS_SUSPENDED)) {
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if (!desc->action)
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return;
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if (!(desc->action->flags & IRQF_FORCE_RESUME))
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return;
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/* Pretend that it got disabled ! */
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desc->depth++;
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}
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desc->istate &= ~IRQS_SUSPENDED;
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}
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switch (desc->depth) {
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case 0:
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err_out:
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WARN(1, KERN_WARNING "Unbalanced enable for IRQ %d\n", irq);
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break;
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case 1: {
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if (desc->istate & IRQS_SUSPENDED)
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goto err_out;
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/* Prevent probing on this irq: */
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irq_settings_set_noprobe(desc);
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irq_enable(desc);
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check_irq_resend(desc, irq);
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/* fall-through */
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}
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default:
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desc->depth--;
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}
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}
|
|
|
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/**
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* enable_irq - enable handling of an irq
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* @irq: Interrupt to enable
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*
|
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* Undoes the effect of one call to disable_irq(). If this
|
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* matches the last disable, processing of interrupts on this
|
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* IRQ line is re-enabled.
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*
|
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* This function may be called from IRQ context only when
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* desc->irq_data.chip->bus_lock and desc->chip->bus_sync_unlock are NULL !
|
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*/
|
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void enable_irq(unsigned int irq)
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{
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unsigned long flags;
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struct irq_desc *desc = irq_get_desc_buslock(irq, &flags, IRQ_GET_DESC_CHECK_GLOBAL);
|
|
|
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if (!desc)
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return;
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if (WARN(!desc->irq_data.chip,
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KERN_ERR "enable_irq before setup/request_irq: irq %u\n", irq))
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goto out;
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|
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__enable_irq(desc, irq, false);
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out:
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irq_put_desc_busunlock(desc, flags);
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}
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EXPORT_SYMBOL(enable_irq);
|
|
|
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static int set_irq_wake_real(unsigned int irq, unsigned int on)
|
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{
|
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struct irq_desc *desc = irq_to_desc(irq);
|
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int ret = -ENXIO;
|
|
|
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if (irq_desc_get_chip(desc)->flags & IRQCHIP_SKIP_SET_WAKE)
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return 0;
|
|
|
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if (desc->irq_data.chip->irq_set_wake)
|
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ret = desc->irq_data.chip->irq_set_wake(&desc->irq_data, on);
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|
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return ret;
|
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}
|
|
|
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/**
|
|
* irq_set_irq_wake - control irq power management wakeup
|
|
* @irq: interrupt to control
|
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* @on: enable/disable power management wakeup
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*
|
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* Enable/disable power management wakeup mode, which is
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* disabled by default. Enables and disables must match,
|
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* just as they match for non-wakeup mode support.
|
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*
|
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* Wakeup mode lets this IRQ wake the system from sleep
|
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* states like "suspend to RAM".
|
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*/
|
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int irq_set_irq_wake(unsigned int irq, unsigned int on)
|
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{
|
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unsigned long flags;
|
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struct irq_desc *desc = irq_get_desc_buslock(irq, &flags, IRQ_GET_DESC_CHECK_GLOBAL);
|
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int ret = 0;
|
|
|
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if (!desc)
|
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return -EINVAL;
|
|
|
|
/* 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);
|
|
}
|
|
}
|
|
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)
|
|
if (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 int irq,
|
|
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,
|
|
chip ? (chip->name ? : "unknown") : "unknown");
|
|
return 0;
|
|
}
|
|
|
|
flags &= IRQ_TYPE_SENSE_MASK;
|
|
|
|
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;
|
|
}
|
|
|
|
/* caller masked out all except trigger mode flags */
|
|
ret = chip->irq_set_type(&desc->irq_data, flags);
|
|
|
|
switch (ret) {
|
|
case IRQ_SET_MASK_OK:
|
|
irqd_clear(&desc->irq_data, IRQD_TRIGGER_MASK);
|
|
irqd_set(&desc->irq_data, flags);
|
|
|
|
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 (%pF)\n",
|
|
flags, irq, 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;
|
|
}
|
|
#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 int irq_wait_for_interrupt(struct irqaction *action)
|
|
{
|
|
set_current_state(TASK_INTERRUPTIBLE);
|
|
|
|
while (!kthread_should_stop()) {
|
|
|
|
if (test_and_clear_bit(IRQTF_RUNTHREAD,
|
|
&action->thread_flags)) {
|
|
__set_current_state(TASK_RUNNING);
|
|
return 0;
|
|
}
|
|
schedule();
|
|
set_current_state(TASK_INTERRUPTIBLE);
|
|
}
|
|
__set_current_state(TASK_RUNNING);
|
|
return -1;
|
|
}
|
|
|
|
/*
|
|
* 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))
|
|
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_onehsot |= 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_irq(desc);
|
|
|
|
out_unlock:
|
|
raw_spin_unlock_irq(&desc->lock);
|
|
chip_bus_sync_unlock(desc);
|
|
}
|
|
|
|
#ifdef CONFIG_SMP
|
|
/*
|
|
* Check whether we need to chasnge 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 (desc->irq_data.affinity)
|
|
cpumask_copy(mask, desc->irq_data.affinity);
|
|
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 explicitely 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();
|
|
ret = action->thread_fn(action->irq, action->dev_id);
|
|
irq_finalize_oneshot(desc, action);
|
|
local_bh_enable();
|
|
return ret;
|
|
}
|
|
|
|
/*
|
|
* Interrupts explicitely requested as threaded interupts want to be
|
|
* preemtible - 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);
|
|
irq_finalize_oneshot(desc, action);
|
|
return ret;
|
|
}
|
|
|
|
static void wake_threads_waitq(struct irq_desc *desc)
|
|
{
|
|
if (atomic_dec_and_test(&desc->threads_active) &&
|
|
waitqueue_active(&desc->wait_for_threads))
|
|
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);
|
|
}
|
|
|
|
/*
|
|
* Interrupt handler thread
|
|
*/
|
|
static int irq_thread(void *data)
|
|
{
|
|
struct callback_head on_exit_work;
|
|
static const struct sched_param param = {
|
|
.sched_priority = MAX_USER_RT_PRIO/2,
|
|
};
|
|
struct irqaction *action = data;
|
|
struct irq_desc *desc = irq_to_desc(action->irq);
|
|
irqreturn_t (*handler_fn)(struct irq_desc *desc,
|
|
struct irqaction *action);
|
|
|
|
if (force_irqthreads && test_bit(IRQTF_FORCED_THREAD,
|
|
&action->thread_flags))
|
|
handler_fn = irq_forced_thread_fn;
|
|
else
|
|
handler_fn = irq_thread_fn;
|
|
|
|
sched_setscheduler(current, SCHED_FIFO, ¶m);
|
|
|
|
init_task_work(&on_exit_work, irq_thread_dtor);
|
|
task_work_add(current, &on_exit_work, false);
|
|
|
|
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 (!noirqdebug)
|
|
note_interrupt(action->irq, desc, action_ret);
|
|
|
|
wake_threads_waitq(desc);
|
|
}
|
|
|
|
/*
|
|
* This is the regular exit path. __free_irq() is stopping the
|
|
* thread via kthread_stop() after calling
|
|
* synchronize_irq(). So neither IRQTF_RUNTHREAD nor the
|
|
* oneshot mask bit can be set. We cannot verify that as we
|
|
* cannot touch the oneshot mask at this point anymore as
|
|
* __setup_irq() might have given out currents thread_mask
|
|
* again.
|
|
*/
|
|
task_work_cancel(current, irq_thread_dtor);
|
|
return 0;
|
|
}
|
|
|
|
static void irq_setup_forced_threading(struct irqaction *new)
|
|
{
|
|
if (!force_irqthreads)
|
|
return;
|
|
if (new->flags & (IRQF_NO_THREAD | IRQF_PERCPU | IRQF_ONESHOT))
|
|
return;
|
|
|
|
new->flags |= IRQF_ONESHOT;
|
|
|
|
if (!new->thread_fn) {
|
|
set_bit(IRQTF_FORCED_THREAD, &new->thread_flags);
|
|
new->thread_fn = new->handler;
|
|
new->handler = irq_default_primary_handler;
|
|
}
|
|
}
|
|
|
|
/*
|
|
* Internal function to register an irqaction - typically used to
|
|
* allocate special interrupts that are part of the architecture.
|
|
*/
|
|
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;
|
|
cpumask_var_t mask;
|
|
|
|
if (!desc)
|
|
return -EINVAL;
|
|
|
|
if (desc->irq_data.chip == &no_irq_chip)
|
|
return -ENOSYS;
|
|
if (!try_module_get(desc->owner))
|
|
return -ENODEV;
|
|
|
|
/*
|
|
* 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))
|
|
irq_setup_forced_threading(new);
|
|
}
|
|
|
|
/*
|
|
* 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) {
|
|
struct task_struct *t;
|
|
|
|
t = kthread_create(irq_thread, new, "irq/%d-%s", irq,
|
|
new->name);
|
|
if (IS_ERR(t)) {
|
|
ret = PTR_ERR(t);
|
|
goto out_mput;
|
|
}
|
|
/*
|
|
* 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.
|
|
*/
|
|
get_task_struct(t);
|
|
new->thread = 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);
|
|
}
|
|
|
|
if (!alloc_cpumask_var(&mask, GFP_KERNEL)) {
|
|
ret = -ENOMEM;
|
|
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;
|
|
|
|
/*
|
|
* The following block of code has to be executed atomically
|
|
*/
|
|
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.
|
|
*/
|
|
if (!((old->flags & new->flags) & IRQF_SHARED) ||
|
|
((old->flags ^ 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_mask;
|
|
}
|
|
/*
|
|
* 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 = 1 << 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 irq %d\n",
|
|
irq);
|
|
ret = -EINVAL;
|
|
goto out_mask;
|
|
}
|
|
|
|
if (!shared) {
|
|
init_waitqueue_head(&desc->wait_for_threads);
|
|
|
|
/* Setup the type (level, edge polarity) if configured: */
|
|
if (new->flags & IRQF_TRIGGER_MASK) {
|
|
ret = __irq_set_trigger(desc, irq,
|
|
new->flags & IRQF_TRIGGER_MASK);
|
|
|
|
if (ret)
|
|
goto out_mask;
|
|
}
|
|
|
|
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_ONESHOT)
|
|
desc->istate |= IRQS_ONESHOT;
|
|
|
|
if (irq_settings_can_autoenable(desc))
|
|
irq_startup(desc, true);
|
|
else
|
|
/* Undo nested disables: */
|
|
desc->depth = 1;
|
|
|
|
/* 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);
|
|
}
|
|
|
|
/* Set default affinity mask once everything is setup */
|
|
setup_affinity(irq, desc, mask);
|
|
|
|
} else if (new->flags & IRQF_TRIGGER_MASK) {
|
|
unsigned int nmsk = new->flags & IRQF_TRIGGER_MASK;
|
|
unsigned int omsk = irq_settings_get_trigger_mask(desc);
|
|
|
|
if (nmsk != omsk)
|
|
/* hope the handler works with current trigger mode */
|
|
pr_warning("irq %d uses trigger mode %u; requested %u\n",
|
|
irq, nmsk, omsk);
|
|
}
|
|
|
|
new->irq = irq;
|
|
*old_ptr = 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, irq, false);
|
|
}
|
|
|
|
raw_spin_unlock_irqrestore(&desc->lock, flags);
|
|
|
|
/*
|
|
* Strictly no need to wake it up, but hung_task complains
|
|
* when no hard interrupt wakes the thread up.
|
|
*/
|
|
if (new->thread)
|
|
wake_up_process(new->thread);
|
|
|
|
register_irq_proc(irq, desc);
|
|
new->dir = NULL;
|
|
register_handler_proc(irq, new);
|
|
free_cpumask_var(mask);
|
|
|
|
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_mask:
|
|
raw_spin_unlock_irqrestore(&desc->lock, flags);
|
|
free_cpumask_var(mask);
|
|
|
|
out_thread:
|
|
if (new->thread) {
|
|
struct task_struct *t = new->thread;
|
|
|
|
new->thread = NULL;
|
|
kthread_stop(t);
|
|
put_task_struct(t);
|
|
}
|
|
out_mput:
|
|
module_put(desc->owner);
|
|
return ret;
|
|
}
|
|
|
|
/**
|
|
* setup_irq - setup an interrupt
|
|
* @irq: Interrupt line to setup
|
|
* @act: irqaction for the interrupt
|
|
*
|
|
* Used to statically setup interrupts in the early boot process.
|
|
*/
|
|
int setup_irq(unsigned int irq, struct irqaction *act)
|
|
{
|
|
int retval;
|
|
struct irq_desc *desc = irq_to_desc(irq);
|
|
|
|
if (WARN_ON(irq_settings_is_per_cpu_devid(desc)))
|
|
return -EINVAL;
|
|
chip_bus_lock(desc);
|
|
retval = __setup_irq(irq, desc, act);
|
|
chip_bus_sync_unlock(desc);
|
|
|
|
return retval;
|
|
}
|
|
EXPORT_SYMBOL_GPL(setup_irq);
|
|
|
|
/*
|
|
* Internal function to unregister an irqaction - used to free
|
|
* regular and special interrupts that are part of the architecture.
|
|
*/
|
|
static struct irqaction *__free_irq(unsigned int irq, void *dev_id)
|
|
{
|
|
struct irq_desc *desc = irq_to_desc(irq);
|
|
struct irqaction *action, **action_ptr;
|
|
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);
|
|
|
|
/*
|
|
* 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);
|
|
|
|
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;
|
|
|
|
/* If this was the last handler, shut down the IRQ line: */
|
|
if (!desc->action)
|
|
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);
|
|
|
|
unregister_handler_proc(irq, action);
|
|
|
|
/* Make sure it's not being used on another CPU: */
|
|
synchronize_irq(irq);
|
|
|
|
#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
|
|
|
|
if (action->thread) {
|
|
kthread_stop(action->thread);
|
|
put_task_struct(action->thread);
|
|
}
|
|
|
|
module_put(desc->owner);
|
|
return action;
|
|
}
|
|
|
|
/**
|
|
* remove_irq - free an interrupt
|
|
* @irq: Interrupt line to free
|
|
* @act: irqaction for the interrupt
|
|
*
|
|
* Used to remove interrupts statically setup by the early boot process.
|
|
*/
|
|
void remove_irq(unsigned int irq, struct irqaction *act)
|
|
{
|
|
struct irq_desc *desc = irq_to_desc(irq);
|
|
|
|
if (desc && !WARN_ON(irq_settings_is_per_cpu_devid(desc)))
|
|
__free_irq(irq, act->dev_id);
|
|
}
|
|
EXPORT_SYMBOL_GPL(remove_irq);
|
|
|
|
/**
|
|
* 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.
|
|
*/
|
|
void free_irq(unsigned int irq, void *dev_id)
|
|
{
|
|
struct irq_desc *desc = irq_to_desc(irq);
|
|
|
|
if (!desc || WARN_ON(irq_settings_is_per_cpu_devid(desc)))
|
|
return;
|
|
|
|
#ifdef CONFIG_SMP
|
|
if (WARN_ON(desc->affinity_notify))
|
|
desc->affinity_notify = NULL;
|
|
#endif
|
|
|
|
chip_bus_lock(desc);
|
|
kfree(__free_irq(irq, dev_id));
|
|
chip_bus_sync_unlock(desc);
|
|
}
|
|
EXPORT_SYMBOL(free_irq);
|
|
|
|
/**
|
|
* 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 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
|
|
*
|
|
*/
|
|
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;
|
|
|
|
/*
|
|
* 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).
|
|
*/
|
|
if ((irqflags & IRQF_SHARED) && !dev_id)
|
|
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;
|
|
|
|
chip_bus_lock(desc);
|
|
retval = __setup_irq(irq, desc, action);
|
|
chip_bus_sync_unlock(desc);
|
|
|
|
if (retval)
|
|
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 = irq_to_desc(irq);
|
|
int ret;
|
|
|
|
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);
|
|
|
|
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;
|
|
|
|
type &= IRQ_TYPE_SENSE_MASK;
|
|
if (type != IRQ_TYPE_NONE) {
|
|
int ret;
|
|
|
|
ret = __irq_set_trigger(desc, irq, 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);
|
|
}
|
|
|
|
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);
|
|
}
|
|
|
|
/*
|
|
* 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;
|
|
|
|
raw_spin_unlock_irqrestore(&desc->lock, flags);
|
|
|
|
unregister_handler_proc(irq, action);
|
|
|
|
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
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|
*
|
|
* Used to remove interrupts statically setup by the early boot process.
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|
*/
|
|
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))
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|
__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);
|
|
}
|
|
|
|
/**
|
|
* 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;
|
|
chip_bus_lock(desc);
|
|
retval = __setup_irq(irq, desc, act);
|
|
chip_bus_sync_unlock(desc);
|
|
|
|
return retval;
|
|
}
|
|
|
|
/**
|
|
* request_percpu_irq - allocate a percpu interrupt line
|
|
* @irq: Interrupt line to allocate
|
|
* @handler: Function to be called when the IRQ occurs.
|
|
* @devname: An ascii name for the claiming device
|
|
* @dev_id: A percpu cookie passed back to the handler function
|
|
*
|
|
* This call allocates interrupt resources, but doesn't
|
|
* automatically enable the interrupt. 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,
|
|
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;
|
|
|
|
action = kzalloc(sizeof(struct irqaction), GFP_KERNEL);
|
|
if (!action)
|
|
return -ENOMEM;
|
|
|
|
action->handler = handler;
|
|
action->flags = IRQF_PERCPU | IRQF_NO_SUSPEND;
|
|
action->name = devname;
|
|
action->percpu_dev_id = dev_id;
|
|
|
|
chip_bus_lock(desc);
|
|
retval = __setup_irq(irq, desc, action);
|
|
chip_bus_sync_unlock(desc);
|
|
|
|
if (retval)
|
|
kfree(action);
|
|
|
|
return retval;
|
|
}
|