| /* |
| * linux/kernel/irq/handle.c |
| * |
| * Copyright (C) 1992, 1998-2006 Linus Torvalds, Ingo Molnar |
| * Copyright (C) 2005-2006, Thomas Gleixner, Russell King |
| * |
| * This file contains the core interrupt handling code. |
| * |
| * Detailed information is available in Documentation/DocBook/genericirq |
| * |
| */ |
| |
| #include <linux/irq.h> |
| #include <linux/slab.h> |
| #include <linux/module.h> |
| #include <linux/random.h> |
| #include <linux/interrupt.h> |
| #include <linux/kernel_stat.h> |
| #include <linux/rculist.h> |
| #include <linux/hash.h> |
| #include <linux/bootmem.h> |
| #include <trace/events/irq.h> |
| |
| #include "internals.h" |
| |
| /* |
| * lockdep: we want to handle all irq_desc locks as a single lock-class: |
| */ |
| struct lock_class_key irq_desc_lock_class; |
| |
| /** |
| * handle_bad_irq - handle spurious and unhandled irqs |
| * @irq: the interrupt number |
| * @desc: description of the interrupt |
| * |
| * Handles spurious and unhandled IRQ's. It also prints a debugmessage. |
| */ |
| void handle_bad_irq(unsigned int irq, struct irq_desc *desc) |
| { |
| print_irq_desc(irq, desc); |
| kstat_incr_irqs_this_cpu(irq, desc); |
| ack_bad_irq(irq); |
| } |
| |
| #if defined(CONFIG_SMP) && defined(CONFIG_GENERIC_HARDIRQS) |
| static void __init init_irq_default_affinity(void) |
| { |
| alloc_cpumask_var(&irq_default_affinity, GFP_NOWAIT); |
| cpumask_setall(irq_default_affinity); |
| } |
| #else |
| static void __init init_irq_default_affinity(void) |
| { |
| } |
| #endif |
| |
| /* |
| * Linux has a controller-independent interrupt architecture. |
| * Every controller has a 'controller-template', that is used |
| * by the main code to do the right thing. Each driver-visible |
| * interrupt source is transparently wired to the appropriate |
| * controller. Thus drivers need not be aware of the |
| * interrupt-controller. |
| * |
| * The code is designed to be easily extended with new/different |
| * interrupt controllers, without having to do assembly magic or |
| * having to touch the generic code. |
| * |
| * Controller mappings for all interrupt sources: |
| */ |
| int nr_irqs = NR_IRQS; |
| EXPORT_SYMBOL_GPL(nr_irqs); |
| |
| #ifdef CONFIG_SPARSE_IRQ |
| |
| static struct irq_desc irq_desc_init = { |
| .irq = -1, |
| .status = IRQ_DISABLED, |
| .chip = &no_irq_chip, |
| .handle_irq = handle_bad_irq, |
| .depth = 1, |
| .lock = __SPIN_LOCK_UNLOCKED(irq_desc_init.lock), |
| }; |
| |
| void __ref init_kstat_irqs(struct irq_desc *desc, int node, int nr) |
| { |
| void *ptr; |
| |
| if (slab_is_available()) |
| ptr = kzalloc_node(nr * sizeof(*desc->kstat_irqs), |
| GFP_ATOMIC, node); |
| else |
| ptr = alloc_bootmem_node(NODE_DATA(node), |
| nr * sizeof(*desc->kstat_irqs)); |
| |
| /* |
| * don't overwite if can not get new one |
| * init_copy_kstat_irqs() could still use old one |
| */ |
| if (ptr) { |
| printk(KERN_DEBUG " alloc kstat_irqs on node %d\n", node); |
| desc->kstat_irqs = ptr; |
| } |
| } |
| |
| static void init_one_irq_desc(int irq, struct irq_desc *desc, int node) |
| { |
| memcpy(desc, &irq_desc_init, sizeof(struct irq_desc)); |
| |
| spin_lock_init(&desc->lock); |
| desc->irq = irq; |
| #ifdef CONFIG_SMP |
| desc->node = node; |
| #endif |
| lockdep_set_class(&desc->lock, &irq_desc_lock_class); |
| init_kstat_irqs(desc, node, nr_cpu_ids); |
| if (!desc->kstat_irqs) { |
| printk(KERN_ERR "can not alloc kstat_irqs\n"); |
| BUG_ON(1); |
| } |
| if (!alloc_desc_masks(desc, node, false)) { |
| printk(KERN_ERR "can not alloc irq_desc cpumasks\n"); |
| BUG_ON(1); |
| } |
| init_desc_masks(desc); |
| arch_init_chip_data(desc, node); |
| } |
| |
| /* |
| * Protect the sparse_irqs: |
| */ |
| DEFINE_SPINLOCK(sparse_irq_lock); |
| |
| struct irq_desc **irq_desc_ptrs __read_mostly; |
| |
| static struct irq_desc irq_desc_legacy[NR_IRQS_LEGACY] __cacheline_aligned_in_smp = { |
| [0 ... NR_IRQS_LEGACY-1] = { |
| .irq = -1, |
| .status = IRQ_DISABLED, |
| .chip = &no_irq_chip, |
| .handle_irq = handle_bad_irq, |
| .depth = 1, |
| .lock = __SPIN_LOCK_UNLOCKED(irq_desc_init.lock), |
| } |
| }; |
| |
| static unsigned int *kstat_irqs_legacy; |
| |
| int __init early_irq_init(void) |
| { |
| struct irq_desc *desc; |
| int legacy_count; |
| int node; |
| int i; |
| |
| init_irq_default_affinity(); |
| |
| /* initialize nr_irqs based on nr_cpu_ids */ |
| arch_probe_nr_irqs(); |
| printk(KERN_INFO "NR_IRQS:%d nr_irqs:%d\n", NR_IRQS, nr_irqs); |
| |
| desc = irq_desc_legacy; |
| legacy_count = ARRAY_SIZE(irq_desc_legacy); |
| node = first_online_node; |
| |
| /* allocate irq_desc_ptrs array based on nr_irqs */ |
| irq_desc_ptrs = kcalloc(nr_irqs, sizeof(void *), GFP_NOWAIT); |
| |
| /* allocate based on nr_cpu_ids */ |
| kstat_irqs_legacy = kzalloc_node(NR_IRQS_LEGACY * nr_cpu_ids * |
| sizeof(int), GFP_NOWAIT, node); |
| |
| for (i = 0; i < legacy_count; i++) { |
| desc[i].irq = i; |
| desc[i].kstat_irqs = kstat_irqs_legacy + i * nr_cpu_ids; |
| lockdep_set_class(&desc[i].lock, &irq_desc_lock_class); |
| alloc_desc_masks(&desc[i], node, true); |
| init_desc_masks(&desc[i]); |
| irq_desc_ptrs[i] = desc + i; |
| } |
| |
| for (i = legacy_count; i < nr_irqs; i++) |
| irq_desc_ptrs[i] = NULL; |
| |
| return arch_early_irq_init(); |
| } |
| |
| struct irq_desc *irq_to_desc(unsigned int irq) |
| { |
| if (irq_desc_ptrs && irq < nr_irqs) |
| return irq_desc_ptrs[irq]; |
| |
| return NULL; |
| } |
| |
| struct irq_desc * __ref irq_to_desc_alloc_node(unsigned int irq, int node) |
| { |
| struct irq_desc *desc; |
| unsigned long flags; |
| |
| if (irq >= nr_irqs) { |
| WARN(1, "irq (%d) >= nr_irqs (%d) in irq_to_desc_alloc\n", |
| irq, nr_irqs); |
| return NULL; |
| } |
| |
| desc = irq_desc_ptrs[irq]; |
| if (desc) |
| return desc; |
| |
| spin_lock_irqsave(&sparse_irq_lock, flags); |
| |
| /* We have to check it to avoid races with another CPU */ |
| desc = irq_desc_ptrs[irq]; |
| if (desc) |
| goto out_unlock; |
| |
| if (slab_is_available()) |
| desc = kzalloc_node(sizeof(*desc), GFP_ATOMIC, node); |
| else |
| desc = alloc_bootmem_node(NODE_DATA(node), sizeof(*desc)); |
| |
| printk(KERN_DEBUG " alloc irq_desc for %d on node %d\n", irq, node); |
| if (!desc) { |
| printk(KERN_ERR "can not alloc irq_desc\n"); |
| BUG_ON(1); |
| } |
| init_one_irq_desc(irq, desc, node); |
| |
| irq_desc_ptrs[irq] = desc; |
| |
| out_unlock: |
| spin_unlock_irqrestore(&sparse_irq_lock, flags); |
| |
| return desc; |
| } |
| |
| #else /* !CONFIG_SPARSE_IRQ */ |
| |
| struct irq_desc irq_desc[NR_IRQS] __cacheline_aligned_in_smp = { |
| [0 ... NR_IRQS-1] = { |
| .status = IRQ_DISABLED, |
| .chip = &no_irq_chip, |
| .handle_irq = handle_bad_irq, |
| .depth = 1, |
| .lock = __SPIN_LOCK_UNLOCKED(irq_desc->lock), |
| } |
| }; |
| |
| static unsigned int kstat_irqs_all[NR_IRQS][NR_CPUS]; |
| int __init early_irq_init(void) |
| { |
| struct irq_desc *desc; |
| int count; |
| int i; |
| |
| init_irq_default_affinity(); |
| |
| printk(KERN_INFO "NR_IRQS:%d\n", NR_IRQS); |
| |
| desc = irq_desc; |
| count = ARRAY_SIZE(irq_desc); |
| |
| for (i = 0; i < count; i++) { |
| desc[i].irq = i; |
| alloc_desc_masks(&desc[i], 0, true); |
| init_desc_masks(&desc[i]); |
| desc[i].kstat_irqs = kstat_irqs_all[i]; |
| } |
| return arch_early_irq_init(); |
| } |
| |
| struct irq_desc *irq_to_desc(unsigned int irq) |
| { |
| return (irq < NR_IRQS) ? irq_desc + irq : NULL; |
| } |
| |
| struct irq_desc *irq_to_desc_alloc_node(unsigned int irq, int node) |
| { |
| return irq_to_desc(irq); |
| } |
| #endif /* !CONFIG_SPARSE_IRQ */ |
| |
| void clear_kstat_irqs(struct irq_desc *desc) |
| { |
| memset(desc->kstat_irqs, 0, nr_cpu_ids * sizeof(*(desc->kstat_irqs))); |
| } |
| |
| /* |
| * What should we do if we get a hw irq event on an illegal vector? |
| * Each architecture has to answer this themself. |
| */ |
| static void ack_bad(unsigned int irq) |
| { |
| struct irq_desc *desc = irq_to_desc(irq); |
| |
| print_irq_desc(irq, desc); |
| ack_bad_irq(irq); |
| } |
| |
| /* |
| * NOP functions |
| */ |
| static void noop(unsigned int irq) |
| { |
| } |
| |
| static unsigned int noop_ret(unsigned int irq) |
| { |
| return 0; |
| } |
| |
| /* |
| * Generic no controller implementation |
| */ |
| struct irq_chip no_irq_chip = { |
| .name = "none", |
| .startup = noop_ret, |
| .shutdown = noop, |
| .enable = noop, |
| .disable = noop, |
| .ack = ack_bad, |
| .end = noop, |
| }; |
| |
| /* |
| * Generic dummy implementation which can be used for |
| * real dumb interrupt sources |
| */ |
| struct irq_chip dummy_irq_chip = { |
| .name = "dummy", |
| .startup = noop_ret, |
| .shutdown = noop, |
| .enable = noop, |
| .disable = noop, |
| .ack = noop, |
| .mask = noop, |
| .unmask = noop, |
| .end = noop, |
| }; |
| |
| /* |
| * Special, empty irq handler: |
| */ |
| irqreturn_t no_action(int cpl, void *dev_id) |
| { |
| return IRQ_NONE; |
| } |
| |
| static void warn_no_thread(unsigned int irq, struct irqaction *action) |
| { |
| if (test_and_set_bit(IRQTF_WARNED, &action->thread_flags)) |
| return; |
| |
| printk(KERN_WARNING "IRQ %d device %s returned IRQ_WAKE_THREAD " |
| "but no thread function available.", irq, action->name); |
| } |
| |
| /** |
| * handle_IRQ_event - irq action chain handler |
| * @irq: the interrupt number |
| * @action: the interrupt action chain for this irq |
| * |
| * Handles the action chain of an irq event |
| */ |
| irqreturn_t handle_IRQ_event(unsigned int irq, struct irqaction *action) |
| { |
| irqreturn_t ret, retval = IRQ_NONE; |
| unsigned int status = 0; |
| |
| if (!(action->flags & IRQF_DISABLED)) |
| local_irq_enable_in_hardirq(); |
| |
| do { |
| trace_irq_handler_entry(irq, action); |
| ret = action->handler(irq, action->dev_id); |
| trace_irq_handler_exit(irq, action, ret); |
| |
| switch (ret) { |
| case IRQ_WAKE_THREAD: |
| /* |
| * Set result to handled so the spurious check |
| * does not trigger. |
| */ |
| ret = IRQ_HANDLED; |
| |
| /* |
| * Catch drivers which return WAKE_THREAD but |
| * did not set up a thread function |
| */ |
| if (unlikely(!action->thread_fn)) { |
| warn_no_thread(irq, action); |
| break; |
| } |
| |
| /* |
| * Wake up the handler thread for this |
| * action. In case the thread crashed and was |
| * killed we just pretend that we handled the |
| * interrupt. The hardirq handler above has |
| * disabled the device interrupt, so no irq |
| * storm is lurking. |
| */ |
| if (likely(!test_bit(IRQTF_DIED, |
| &action->thread_flags))) { |
| set_bit(IRQTF_RUNTHREAD, &action->thread_flags); |
| wake_up_process(action->thread); |
| } |
| |
| /* Fall through to add to randomness */ |
| case IRQ_HANDLED: |
| status |= action->flags; |
| break; |
| |
| default: |
| break; |
| } |
| |
| retval |= ret; |
| action = action->next; |
| } while (action); |
| |
| if (status & IRQF_SAMPLE_RANDOM) |
| add_interrupt_randomness(irq); |
| local_irq_disable(); |
| |
| return retval; |
| } |
| |
| #ifndef CONFIG_GENERIC_HARDIRQS_NO__DO_IRQ |
| |
| #ifdef CONFIG_ENABLE_WARN_DEPRECATED |
| # warning __do_IRQ is deprecated. Please convert to proper flow handlers |
| #endif |
| |
| /** |
| * __do_IRQ - original all in one highlevel IRQ handler |
| * @irq: the interrupt number |
| * |
| * __do_IRQ handles all normal device IRQ's (the special |
| * SMP cross-CPU interrupts have their own specific |
| * handlers). |
| * |
| * This is the original x86 implementation which is used for every |
| * interrupt type. |
| */ |
| unsigned int __do_IRQ(unsigned int irq) |
| { |
| struct irq_desc *desc = irq_to_desc(irq); |
| struct irqaction *action; |
| unsigned int status; |
| |
| kstat_incr_irqs_this_cpu(irq, desc); |
| |
| if (CHECK_IRQ_PER_CPU(desc->status)) { |
| irqreturn_t action_ret; |
| |
| /* |
| * No locking required for CPU-local interrupts: |
| */ |
| if (desc->chip->ack) |
| desc->chip->ack(irq); |
| if (likely(!(desc->status & IRQ_DISABLED))) { |
| action_ret = handle_IRQ_event(irq, desc->action); |
| if (!noirqdebug) |
| note_interrupt(irq, desc, action_ret); |
| } |
| desc->chip->end(irq); |
| return 1; |
| } |
| |
| spin_lock(&desc->lock); |
| if (desc->chip->ack) |
| desc->chip->ack(irq); |
| /* |
| * REPLAY is when Linux resends an IRQ that was dropped earlier |
| * WAITING is used by probe to mark irqs that are being tested |
| */ |
| status = desc->status & ~(IRQ_REPLAY | IRQ_WAITING); |
| status |= IRQ_PENDING; /* we _want_ to handle it */ |
| |
| /* |
| * If the IRQ is disabled for whatever reason, we cannot |
| * use the action we have. |
| */ |
| action = NULL; |
| if (likely(!(status & (IRQ_DISABLED | IRQ_INPROGRESS)))) { |
| action = desc->action; |
| status &= ~IRQ_PENDING; /* we commit to handling */ |
| status |= IRQ_INPROGRESS; /* we are handling it */ |
| } |
| desc->status = status; |
| |
| /* |
| * If there is no IRQ handler or it was disabled, exit early. |
| * Since we set PENDING, if another processor is handling |
| * a different instance of this same irq, the other processor |
| * will take care of it. |
| */ |
| if (unlikely(!action)) |
| goto out; |
| |
| /* |
| * Edge triggered interrupts need to remember |
| * pending events. |
| * This applies to any hw interrupts that allow a second |
| * instance of the same irq to arrive while we are in do_IRQ |
| * or in the handler. But the code here only handles the _second_ |
| * instance of the irq, not the third or fourth. So it is mostly |
| * useful for irq hardware that does not mask cleanly in an |
| * SMP environment. |
| */ |
| for (;;) { |
| irqreturn_t action_ret; |
| |
| spin_unlock(&desc->lock); |
| |
| action_ret = handle_IRQ_event(irq, action); |
| if (!noirqdebug) |
| note_interrupt(irq, desc, action_ret); |
| |
| spin_lock(&desc->lock); |
| if (likely(!(desc->status & IRQ_PENDING))) |
| break; |
| desc->status &= ~IRQ_PENDING; |
| } |
| desc->status &= ~IRQ_INPROGRESS; |
| |
| out: |
| /* |
| * The ->end() handler has to deal with interrupts which got |
| * disabled while the handler was running. |
| */ |
| desc->chip->end(irq); |
| spin_unlock(&desc->lock); |
| |
| return 1; |
| } |
| #endif |
| |
| void early_init_irq_lock_class(void) |
| { |
| struct irq_desc *desc; |
| int i; |
| |
| for_each_irq_desc(i, desc) { |
| lockdep_set_class(&desc->lock, &irq_desc_lock_class); |
| } |
| } |
| |
| unsigned int kstat_irqs_cpu(unsigned int irq, int cpu) |
| { |
| struct irq_desc *desc = irq_to_desc(irq); |
| return desc ? desc->kstat_irqs[cpu] : 0; |
| } |
| EXPORT_SYMBOL(kstat_irqs_cpu); |
| |