/* * linux/arch/arm/kernel/irq.c * * Copyright (C) 1992 Linus Torvalds * Modifications for ARM processor Copyright (C) 1995-2000 Russell King. * * Support for Dynamic Tick Timer Copyright (C) 2004-2005 Nokia Corporation. * Dynamic Tick Timer written by Tony Lindgren <tony@atomide.com> and * Tuukka Tikkanen <tuukka.tikkanen@elektrobit.com>. * * This program is free software; you can redistribute it and/or modify * it under the terms of the GNU General Public License version 2 as * published by the Free Software Foundation. * * This file contains the code used by various IRQ handling routines: * asking for different IRQ's should be done through these routines * instead of just grabbing them. Thus setups with different IRQ numbers * shouldn't result in any weird surprises, and installing new handlers * should be easier. * * IRQ's are in fact implemented a bit like signal handlers for the kernel. * Naturally it's not a 1:1 relation, but there are similarities. */ #include <linux/config.h> #include <linux/kernel_stat.h> #include <linux/module.h> #include <linux/signal.h> #include <linux/ioport.h> #include <linux/interrupt.h> #include <linux/ptrace.h> #include <linux/slab.h> #include <linux/random.h> #include <linux/smp.h> #include <linux/init.h> #include <linux/seq_file.h> #include <linux/errno.h> #include <linux/list.h> #include <linux/kallsyms.h> #include <linux/proc_fs.h> #include <asm/irq.h> #include <asm/system.h> #include <asm/mach/irq.h> #include <asm/mach/time.h> /* * Maximum IRQ count. Currently, this is arbitary. However, it should * not be set too low to prevent false triggering. Conversely, if it * is set too high, then you could miss a stuck IRQ. * * Maybe we ought to set a timer and re-enable the IRQ at a later time? */ #define MAX_IRQ_CNT 100000 static int noirqdebug; static volatile unsigned long irq_err_count; static DEFINE_SPINLOCK(irq_controller_lock); static LIST_HEAD(irq_pending); struct irqdesc irq_desc[NR_IRQS]; void (*init_arch_irq)(void) __initdata = NULL; /* * No architecture-specific irq_finish function defined in arm/arch/irqs.h. */ #ifndef irq_finish #define irq_finish(irq) do { } while (0) #endif /* * Dummy mask/unmask handler */ void dummy_mask_unmask_irq(unsigned int irq) { } irqreturn_t no_action(int irq, void *dev_id, struct pt_regs *regs) { return IRQ_NONE; } void do_bad_IRQ(unsigned int irq, struct irqdesc *desc, struct pt_regs *regs) { irq_err_count += 1; printk(KERN_ERR "IRQ: spurious interrupt %d\n", irq); } static struct irqchip bad_chip = { .ack = dummy_mask_unmask_irq, .mask = dummy_mask_unmask_irq, .unmask = dummy_mask_unmask_irq, }; static struct irqdesc bad_irq_desc = { .chip = &bad_chip, .handle = do_bad_IRQ, .pend = LIST_HEAD_INIT(bad_irq_desc.pend), .disable_depth = 1, }; #ifdef CONFIG_SMP void synchronize_irq(unsigned int irq) { struct irqdesc *desc = irq_desc + irq; while (desc->running) barrier(); } EXPORT_SYMBOL(synchronize_irq); #define smp_set_running(desc) do { desc->running = 1; } while (0) #define smp_clear_running(desc) do { desc->running = 0; } while (0) #else #define smp_set_running(desc) do { } while (0) #define smp_clear_running(desc) do { } while (0) #endif /** * disable_irq_nosync - disable an irq without waiting * @irq: Interrupt to disable * * Disable the selected interrupt line. Enables and disables * are nested. We do this lazily. * * This function may be called from IRQ context. */ void disable_irq_nosync(unsigned int irq) { struct irqdesc *desc = irq_desc + irq; unsigned long flags; spin_lock_irqsave(&irq_controller_lock, flags); desc->disable_depth++; list_del_init(&desc->pend); spin_unlock_irqrestore(&irq_controller_lock, flags); } 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 functions 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. * * This function may be called - with care - from IRQ context. */ void disable_irq(unsigned int irq) { struct irqdesc *desc = irq_desc + irq; disable_irq_nosync(irq); if (desc->action) synchronize_irq(irq); } EXPORT_SYMBOL(disable_irq); /** * enable_irq - enable interrupt handling on an irq * @irq: Interrupt to enable * * Re-enables the processing of interrupts on this IRQ line. * Note that this may call the interrupt handler, so you may * get unexpected results if you hold IRQs disabled. * * This function may be called from IRQ context. */ void enable_irq(unsigned int irq) { struct irqdesc *desc = irq_desc + irq; unsigned long flags; spin_lock_irqsave(&irq_controller_lock, flags); if (unlikely(!desc->disable_depth)) { printk("enable_irq(%u) unbalanced from %p\n", irq, __builtin_return_address(0)); } else if (!--desc->disable_depth) { desc->probing = 0; desc->chip->unmask(irq); /* * If the interrupt is waiting to be processed, * try to re-run it. We can't directly run it * from here since the caller might be in an * interrupt-protected region. */ if (desc->pending && list_empty(&desc->pend)) { desc->pending = 0; if (!desc->chip->retrigger || desc->chip->retrigger(irq)) list_add(&desc->pend, &irq_pending); } } spin_unlock_irqrestore(&irq_controller_lock, flags); } EXPORT_SYMBOL(enable_irq); /* * Enable wake on selected irq */ void enable_irq_wake(unsigned int irq) { struct irqdesc *desc = irq_desc + irq; unsigned long flags; spin_lock_irqsave(&irq_controller_lock, flags); if (desc->chip->set_wake) desc->chip->set_wake(irq, 1); spin_unlock_irqrestore(&irq_controller_lock, flags); } EXPORT_SYMBOL(enable_irq_wake); void disable_irq_wake(unsigned int irq) { struct irqdesc *desc = irq_desc + irq; unsigned long flags; spin_lock_irqsave(&irq_controller_lock, flags); if (desc->chip->set_wake) desc->chip->set_wake(irq, 0); spin_unlock_irqrestore(&irq_controller_lock, flags); } EXPORT_SYMBOL(disable_irq_wake); int show_interrupts(struct seq_file *p, void *v) { int i = *(loff_t *) v, cpu; struct irqaction * action; unsigned long flags; if (i == 0) { char cpuname[12]; seq_printf(p, " "); for_each_present_cpu(cpu) { sprintf(cpuname, "CPU%d", cpu); seq_printf(p, " %10s", cpuname); } seq_putc(p, '\n'); } if (i < NR_IRQS) { spin_lock_irqsave(&irq_controller_lock, flags); action = irq_desc[i].action; if (!action) goto unlock; seq_printf(p, "%3d: ", i); for_each_present_cpu(cpu) seq_printf(p, "%10u ", kstat_cpu(cpu).irqs[i]); seq_printf(p, " %s", action->name); for (action = action->next; action; action = action->next) seq_printf(p, ", %s", action->name); seq_putc(p, '\n'); unlock: spin_unlock_irqrestore(&irq_controller_lock, flags); } else if (i == NR_IRQS) { #ifdef CONFIG_ARCH_ACORN show_fiq_list(p, v); #endif #ifdef CONFIG_SMP show_ipi_list(p); show_local_irqs(p); #endif seq_printf(p, "Err: %10lu\n", irq_err_count); } return 0; } /* * IRQ lock detection. * * Hopefully, this should get us out of a few locked situations. * However, it may take a while for this to happen, since we need * a large number if IRQs to appear in the same jiffie with the * same instruction pointer (or within 2 instructions). */ static int check_irq_lock(struct irqdesc *desc, int irq, struct pt_regs *regs) { unsigned long instr_ptr = instruction_pointer(regs); if (desc->lck_jif == jiffies && desc->lck_pc >= instr_ptr && desc->lck_pc < instr_ptr + 8) { desc->lck_cnt += 1; if (desc->lck_cnt > MAX_IRQ_CNT) { printk(KERN_ERR "IRQ LOCK: IRQ%d is locking the system, disabled\n", irq); return 1; } } else { desc->lck_cnt = 0; desc->lck_pc = instruction_pointer(regs); desc->lck_jif = jiffies; } return 0; } static void report_bad_irq(unsigned int irq, struct pt_regs *regs, struct irqdesc *desc, int ret) { static int count = 100; struct irqaction *action; if (!count || noirqdebug) return; count--; if (ret != IRQ_HANDLED && ret != IRQ_NONE) { printk("irq%u: bogus retval mask %x\n", irq, ret); } else { printk("irq%u: nobody cared\n", irq); } show_regs(regs); dump_stack(); printk(KERN_ERR "handlers:"); action = desc->action; do { printk("\n" KERN_ERR "[<%p>]", action->handler); print_symbol(" (%s)", (unsigned long)action->handler); action = action->next; } while (action); printk("\n"); } static int __do_irq(unsigned int irq, struct irqaction *action, struct pt_regs *regs) { unsigned int status; int ret, retval = 0; spin_unlock(&irq_controller_lock); #ifdef CONFIG_NO_IDLE_HZ if (!(action->flags & SA_TIMER) && system_timer->dyn_tick != NULL) { write_seqlock(&xtime_lock); if (system_timer->dyn_tick->state & DYN_TICK_ENABLED) system_timer->dyn_tick->handler(irq, 0, regs); write_sequnlock(&xtime_lock); } #endif if (!(action->flags & SA_INTERRUPT)) local_irq_enable(); status = 0; do { ret = action->handler(irq, action->dev_id, regs); if (ret == IRQ_HANDLED) status |= action->flags; retval |= ret; action = action->next; } while (action); if (status & SA_SAMPLE_RANDOM) add_interrupt_randomness(irq); spin_lock_irq(&irq_controller_lock); return retval; } /* * This is for software-decoded IRQs. The caller is expected to * handle the ack, clear, mask and unmask issues. */ void do_simple_IRQ(unsigned int irq, struct irqdesc *desc, struct pt_regs *regs) { struct irqaction *action; const unsigned int cpu = smp_processor_id(); desc->triggered = 1; kstat_cpu(cpu).irqs[irq]++; smp_set_running(desc); action = desc->action; if (action) { int ret = __do_irq(irq, action, regs); if (ret != IRQ_HANDLED) report_bad_irq(irq, regs, desc, ret); } smp_clear_running(desc); } /* * Most edge-triggered IRQ implementations seem to take a broken * approach to this. Hence the complexity. */ void do_edge_IRQ(unsigned int irq, struct irqdesc *desc, struct pt_regs *regs) { const unsigned int cpu = smp_processor_id(); desc->triggered = 1; /* * If we're currently running this IRQ, or its disabled, * we shouldn't process the IRQ. Instead, turn on the * hardware masks. */ if (unlikely(desc->running || desc->disable_depth)) goto running; /* * Acknowledge and clear the IRQ, but don't mask it. */ desc->chip->ack(irq); /* * Mark the IRQ currently in progress. */ desc->running = 1; kstat_cpu(cpu).irqs[irq]++; do { struct irqaction *action; action = desc->action; if (!action) break; if (desc->pending && !desc->disable_depth) { desc->pending = 0; desc->chip->unmask(irq); } __do_irq(irq, action, regs); } while (desc->pending && !desc->disable_depth); desc->running = 0; /* * If we were disabled or freed, shut down the handler. */ if (likely(desc->action && !check_irq_lock(desc, irq, regs))) return; running: /* * We got another IRQ while this one was masked or * currently running. Delay it. */ desc->pending = 1; desc->chip->mask(irq); desc->chip->ack(irq); } /* * Level-based IRQ handler. Nice and simple. */ void do_level_IRQ(unsigned int irq, struct irqdesc *desc, struct pt_regs *regs) { struct irqaction *action; const unsigned int cpu = smp_processor_id(); desc->triggered = 1; /* * Acknowledge, clear _AND_ disable the interrupt. */ desc->chip->ack(irq); if (likely(!desc->disable_depth)) { kstat_cpu(cpu).irqs[irq]++; smp_set_running(desc); /* * Return with this interrupt masked if no action */ action = desc->action; if (action) { int ret = __do_irq(irq, desc->action, regs); if (ret != IRQ_HANDLED) report_bad_irq(irq, regs, desc, ret); if (likely(!desc->disable_depth && !check_irq_lock(desc, irq, regs))) desc->chip->unmask(irq); } smp_clear_running(desc); } } static void do_pending_irqs(struct pt_regs *regs) { struct list_head head, *l, *n; do { struct irqdesc *desc; /* * First, take the pending interrupts off the list. * The act of calling the handlers may add some IRQs * back onto the list. */ head = irq_pending; INIT_LIST_HEAD(&irq_pending); head.next->prev = &head; head.prev->next = &head; /* * Now run each entry. We must delete it from our * list before calling the handler. */ list_for_each_safe(l, n, &head) { desc = list_entry(l, struct irqdesc, pend); list_del_init(&desc->pend); desc_handle_irq(desc - irq_desc, desc, regs); } /* * The list must be empty. */ BUG_ON(!list_empty(&head)); } while (!list_empty(&irq_pending)); } /* * do_IRQ handles all hardware IRQ's. Decoded IRQs should not * come via this function. Instead, they should provide their * own 'handler' */ asmlinkage void asm_do_IRQ(unsigned int irq, struct pt_regs *regs) { struct irqdesc *desc = irq_desc + irq; /* * Some hardware gives randomly wrong interrupts. Rather * than crashing, do something sensible. */ if (irq >= NR_IRQS) desc = &bad_irq_desc; irq_enter(); spin_lock(&irq_controller_lock); desc_handle_irq(irq, desc, regs); /* * Now re-run any pending interrupts. */ if (!list_empty(&irq_pending)) do_pending_irqs(regs); irq_finish(irq); spin_unlock(&irq_controller_lock); irq_exit(); } void __set_irq_handler(unsigned int irq, irq_handler_t handle, int is_chained) { struct irqdesc *desc; unsigned long flags; if (irq >= NR_IRQS) { printk(KERN_ERR "Trying to install handler for IRQ%d\n", irq); return; } if (handle == NULL) handle = do_bad_IRQ; desc = irq_desc + irq; if (is_chained && desc->chip == &bad_chip) printk(KERN_WARNING "Trying to install chained handler for IRQ%d\n", irq); spin_lock_irqsave(&irq_controller_lock, flags); if (handle == do_bad_IRQ) { desc->chip->mask(irq); desc->chip->ack(irq); desc->disable_depth = 1; } desc->handle = handle; if (handle != do_bad_IRQ && is_chained) { desc->valid = 0; desc->probe_ok = 0; desc->disable_depth = 0; desc->chip->unmask(irq); } spin_unlock_irqrestore(&irq_controller_lock, flags); } void set_irq_chip(unsigned int irq, struct irqchip *chip) { struct irqdesc *desc; unsigned long flags; if (irq >= NR_IRQS) { printk(KERN_ERR "Trying to install chip for IRQ%d\n", irq); return; } if (chip == NULL) chip = &bad_chip; desc = irq_desc + irq; spin_lock_irqsave(&irq_controller_lock, flags); desc->chip = chip; spin_unlock_irqrestore(&irq_controller_lock, flags); } int set_irq_type(unsigned int irq, unsigned int type) { struct irqdesc *desc; unsigned long flags; int ret = -ENXIO; if (irq >= NR_IRQS) { printk(KERN_ERR "Trying to set irq type for IRQ%d\n", irq); return -ENODEV; } desc = irq_desc + irq; if (desc->chip->set_type) { spin_lock_irqsave(&irq_controller_lock, flags); ret = desc->chip->set_type(irq, type); spin_unlock_irqrestore(&irq_controller_lock, flags); } return ret; } EXPORT_SYMBOL(set_irq_type); void set_irq_flags(unsigned int irq, unsigned int iflags) { struct irqdesc *desc; unsigned long flags; if (irq >= NR_IRQS) { printk(KERN_ERR "Trying to set irq flags for IRQ%d\n", irq); return; } desc = irq_desc + irq; spin_lock_irqsave(&irq_controller_lock, flags); desc->valid = (iflags & IRQF_VALID) != 0; desc->probe_ok = (iflags & IRQF_PROBE) != 0; desc->noautoenable = (iflags & IRQF_NOAUTOEN) != 0; spin_unlock_irqrestore(&irq_controller_lock, flags); } int setup_irq(unsigned int irq, struct irqaction *new) { int shared = 0; struct irqaction *old, **p; unsigned long flags; struct irqdesc *desc; /* * Some drivers like serial.c use request_irq() heavily, * so we have to be careful not to interfere with a * running system. */ if (new->flags & SA_SAMPLE_RANDOM) { /* * This function might sleep, we want to call it first, * outside of the atomic block. * Yes, this might clear the entropy pool if the wrong * driver is attempted to be loaded, without actually * installing a new handler, but is this really a problem, * only the sysadmin is able to do this. */ rand_initialize_irq(irq); } /* * The following block of code has to be executed atomically */ desc = irq_desc + irq; spin_lock_irqsave(&irq_controller_lock, flags); p = &desc->action; if ((old = *p) != NULL) { /* * Can't share interrupts unless both agree to and are * the same type. */ if (!(old->flags & new->flags & SA_SHIRQ) || (~old->flags & new->flags) & SA_TRIGGER_MASK) { spin_unlock_irqrestore(&irq_controller_lock, flags); return -EBUSY; } /* add new interrupt at end of irq queue */ do { p = &old->next; old = *p; } while (old); shared = 1; } *p = new; if (!shared) { desc->probing = 0; desc->running = 0; desc->pending = 0; desc->disable_depth = 1; if (new->flags & SA_TRIGGER_MASK && desc->chip->set_type) { unsigned int type = new->flags & SA_TRIGGER_MASK; desc->chip->set_type(irq, type); } if (!desc->noautoenable) { desc->disable_depth = 0; desc->chip->unmask(irq); } } spin_unlock_irqrestore(&irq_controller_lock, flags); return 0; } /** * request_irq - allocate an interrupt line * @irq: Interrupt line to allocate * @handler: Function to be called when the IRQ occurs * @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. * * 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: * * SA_SHIRQ Interrupt is shared * * SA_INTERRUPT Disable local interrupts while processing * * SA_SAMPLE_RANDOM The interrupt can be used for entropy * */ int request_irq(unsigned int irq, irqreturn_t (*handler)(int, void *, struct pt_regs *), unsigned long irq_flags, const char * devname, void *dev_id) { unsigned long retval; struct irqaction *action; if (irq >= NR_IRQS || !irq_desc[irq].valid || !handler || (irq_flags & SA_SHIRQ && !dev_id)) return -EINVAL; action = (struct irqaction *)kmalloc(sizeof(struct irqaction), GFP_KERNEL); if (!action) return -ENOMEM; action->handler = handler; action->flags = irq_flags; cpus_clear(action->mask); action->name = devname; action->next = NULL; action->dev_id = dev_id; retval = setup_irq(irq, action); if (retval) kfree(action); return retval; } EXPORT_SYMBOL(request_irq); /** * free_irq - free an interrupt * @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. * * This function must not be called from interrupt context. */ void free_irq(unsigned int irq, void *dev_id) { struct irqaction * action, **p; unsigned long flags; if (irq >= NR_IRQS || !irq_desc[irq].valid) { printk(KERN_ERR "Trying to free IRQ%d\n",irq); dump_stack(); return; } spin_lock_irqsave(&irq_controller_lock, flags); for (p = &irq_desc[irq].action; (action = *p) != NULL; p = &action->next) { if (action->dev_id != dev_id) continue; /* Found it - now free it */ *p = action->next; break; } spin_unlock_irqrestore(&irq_controller_lock, flags); if (!action) { printk(KERN_ERR "Trying to free free IRQ%d\n",irq); dump_stack(); } else { synchronize_irq(irq); kfree(action); } } EXPORT_SYMBOL(free_irq); static DECLARE_MUTEX(probe_sem); /* Start the interrupt probing. Unlike other architectures, * we don't return a mask of interrupts from probe_irq_on, * but return the number of interrupts enabled for the probe. * The interrupts which have been enabled for probing is * instead recorded in the irq_desc structure. */ unsigned long probe_irq_on(void) { unsigned int i, irqs = 0; unsigned long delay; down(&probe_sem); /* * first snaffle up any unassigned but * probe-able interrupts */ spin_lock_irq(&irq_controller_lock); for (i = 0; i < NR_IRQS; i++) { if (!irq_desc[i].probe_ok || irq_desc[i].action) continue; irq_desc[i].probing = 1; irq_desc[i].triggered = 0; if (irq_desc[i].chip->set_type) irq_desc[i].chip->set_type(i, IRQT_PROBE); irq_desc[i].chip->unmask(i); irqs += 1; } spin_unlock_irq(&irq_controller_lock); /* * wait for spurious interrupts to mask themselves out again */ for (delay = jiffies + HZ/10; time_before(jiffies, delay); ) /* min 100ms delay */; /* * now filter out any obviously spurious interrupts */ spin_lock_irq(&irq_controller_lock); for (i = 0; i < NR_IRQS; i++) { if (irq_desc[i].probing && irq_desc[i].triggered) { irq_desc[i].probing = 0; irqs -= 1; } } spin_unlock_irq(&irq_controller_lock); return irqs; } EXPORT_SYMBOL(probe_irq_on); unsigned int probe_irq_mask(unsigned long irqs) { unsigned int mask = 0, i; spin_lock_irq(&irq_controller_lock); for (i = 0; i < 16 && i < NR_IRQS; i++) if (irq_desc[i].probing && irq_desc[i].triggered) mask |= 1 << i; spin_unlock_irq(&irq_controller_lock); up(&probe_sem); return mask; } EXPORT_SYMBOL(probe_irq_mask); /* * Possible return values: * >= 0 - interrupt number * -1 - no interrupt/many interrupts */ int probe_irq_off(unsigned long irqs) { unsigned int i; int irq_found = NO_IRQ; /* * look at the interrupts, and find exactly one * that we were probing has been triggered */ spin_lock_irq(&irq_controller_lock); for (i = 0; i < NR_IRQS; i++) { if (irq_desc[i].probing && irq_desc[i].triggered) { if (irq_found != NO_IRQ) { irq_found = NO_IRQ; goto out; } irq_found = i; } } if (irq_found == -1) irq_found = NO_IRQ; out: spin_unlock_irq(&irq_controller_lock); up(&probe_sem); return irq_found; } EXPORT_SYMBOL(probe_irq_off); #ifdef CONFIG_SMP static void route_irq(struct irqdesc *desc, unsigned int irq, unsigned int cpu) { pr_debug("IRQ%u: moving from cpu%u to cpu%u\n", irq, desc->cpu, cpu); spin_lock_irq(&irq_controller_lock); desc->cpu = cpu; desc->chip->set_cpu(desc, irq, cpu); spin_unlock_irq(&irq_controller_lock); } #ifdef CONFIG_PROC_FS static int irq_affinity_read_proc(char *page, char **start, off_t off, int count, int *eof, void *data) { struct irqdesc *desc = irq_desc + ((int)data); int len = cpumask_scnprintf(page, count, desc->affinity); if (count - len < 2) return -EINVAL; page[len++] = '\n'; page[len] = '\0'; return len; } static int irq_affinity_write_proc(struct file *file, const char __user *buffer, unsigned long count, void *data) { unsigned int irq = (unsigned int)data; struct irqdesc *desc = irq_desc + irq; cpumask_t affinity, tmp; int ret = -EIO; if (!desc->chip->set_cpu) goto out; ret = cpumask_parse(buffer, count, affinity); if (ret) goto out; cpus_and(tmp, affinity, cpu_online_map); if (cpus_empty(tmp)) { ret = -EINVAL; goto out; } desc->affinity = affinity; route_irq(desc, irq, first_cpu(tmp)); ret = count; out: return ret; } #endif #endif void __init init_irq_proc(void) { #if defined(CONFIG_SMP) && defined(CONFIG_PROC_FS) struct proc_dir_entry *dir; int irq; dir = proc_mkdir("irq", NULL); if (!dir) return; for (irq = 0; irq < NR_IRQS; irq++) { struct proc_dir_entry *entry; struct irqdesc *desc; char name[16]; desc = irq_desc + irq; memset(name, 0, sizeof(name)); snprintf(name, sizeof(name) - 1, "%u", irq); desc->procdir = proc_mkdir(name, dir); if (!desc->procdir) continue; entry = create_proc_entry("smp_affinity", 0600, desc->procdir); if (entry) { entry->nlink = 1; entry->data = (void *)irq; entry->read_proc = irq_affinity_read_proc; entry->write_proc = irq_affinity_write_proc; } } #endif } void __init init_IRQ(void) { struct irqdesc *desc; int irq; #ifdef CONFIG_SMP bad_irq_desc.affinity = CPU_MASK_ALL; bad_irq_desc.cpu = smp_processor_id(); #endif for (irq = 0, desc = irq_desc; irq < NR_IRQS; irq++, desc++) { *desc = bad_irq_desc; INIT_LIST_HEAD(&desc->pend); } init_arch_irq(); } static int __init noirqdebug_setup(char *str) { noirqdebug = 1; return 1; } __setup("noirqdebug", noirqdebug_setup); #ifdef CONFIG_HOTPLUG_CPU /* * The CPU has been marked offline. Migrate IRQs off this CPU. If * the affinity settings do not allow other CPUs, force them onto any * available CPU. */ void migrate_irqs(void) { unsigned int i, cpu = smp_processor_id(); for (i = 0; i < NR_IRQS; i++) { struct irqdesc *desc = irq_desc + i; if (desc->cpu == cpu) { unsigned int newcpu = any_online_cpu(desc->affinity); if (newcpu == NR_CPUS) { if (printk_ratelimit()) printk(KERN_INFO "IRQ%u no longer affine to CPU%u\n", i, cpu); cpus_setall(desc->affinity); newcpu = any_online_cpu(desc->affinity); } route_irq(desc, i, newcpu); } } } #endif /* CONFIG_HOTPLUG_CPU */