/* * Copyright (C) 2000 Jeff Dike (jdike@karaya.com) * Licensed under the GPL * Derived (i.e. mostly copied) from arch/i386/kernel/irq.c: * Copyright (C) 1992, 1998 Linus Torvalds, Ingo Molnar */ #include "linux/config.h" #include "linux/kernel.h" #include "linux/module.h" #include "linux/smp.h" #include "linux/irq.h" #include "linux/kernel_stat.h" #include "linux/interrupt.h" #include "linux/random.h" #include "linux/slab.h" #include "linux/file.h" #include "linux/proc_fs.h" #include "linux/init.h" #include "linux/seq_file.h" #include "asm/irq.h" #include "asm/hw_irq.h" #include "asm/hardirq.h" #include "asm/atomic.h" #include "asm/signal.h" #include "asm/system.h" #include "asm/errno.h" #include "asm/uaccess.h" #include "user_util.h" #include "kern_util.h" #include "irq_user.h" static void register_irq_proc (unsigned int irq); irq_desc_t irq_desc[NR_IRQS] __cacheline_aligned = { [0 ... NR_IRQS-1] = { .handler = &no_irq_type, .lock = SPIN_LOCK_UNLOCKED } }; /* * Generic no controller code */ static void enable_none(unsigned int irq) { } static unsigned int startup_none(unsigned int irq) { return 0; } static void disable_none(unsigned int irq) { } static void ack_none(unsigned int irq) { /* * 'what should we do if we get a hw irq event on an illegal vector'. * each architecture has to answer this themselves, it doesn't deserve * a generic callback i think. */ #ifdef CONFIG_X86 printk(KERN_ERR "unexpected IRQ trap at vector %02x\n", irq); #ifdef CONFIG_X86_LOCAL_APIC /* * Currently unexpected vectors happen only on SMP and APIC. * We _must_ ack these because every local APIC has only N * irq slots per priority level, and a 'hanging, unacked' IRQ * holds up an irq slot - in excessive cases (when multiple * unexpected vectors occur) that might lock up the APIC * completely. */ ack_APIC_irq(); #endif #endif } /* startup is the same as "enable", shutdown is same as "disable" */ #define shutdown_none disable_none #define end_none enable_none struct hw_interrupt_type no_irq_type = { "none", startup_none, shutdown_none, enable_none, disable_none, ack_none, end_none }; /* Not changed */ volatile unsigned long irq_err_count; /* * Generic, controller-independent functions: */ int get_irq_list(char *buf) { int i, j; unsigned long flags; struct irqaction * action; char *p = buf; p += sprintf(p, " "); for (j=0; jtypename); p += sprintf(p, " %s", action->name); for (action=action->next; action; action = action->next) p += sprintf(p, ", %s", action->name); *p++ = '\n'; end: spin_unlock_irqrestore(&irq_desc[i].lock, flags); } p += sprintf(p, "\n"); #ifdef notdef #ifdef CONFIG_SMP p += sprintf(p, "LOC: "); for (j = 0; j < num_online_cpus(); j++) p += sprintf(p, "%10u ", apic_timer_irqs[cpu_logical_map(j)]); p += sprintf(p, "\n"); #endif #endif p += sprintf(p, "ERR: %10lu\n", irq_err_count); return p - buf; } int show_interrupts(struct seq_file *p, void *v) { return(0); } /* * This should really return information about whether * we should do bottom half handling etc. Right now we * end up _always_ checking the bottom half, which is a * waste of time and is not what some drivers would * prefer. */ int handle_IRQ_event(unsigned int irq, struct pt_regs * regs, struct irqaction * action) { int status = 1; /* Force the "do bottom halves" bit */ if (!(action->flags & SA_INTERRUPT)) local_irq_enable(); do { status |= action->flags; action->handler(irq, action->dev_id, regs); action = action->next; } while (action); if (status & SA_SAMPLE_RANDOM) add_interrupt_randomness(irq); local_irq_disable(); return status; } /* * Generic enable/disable code: this just calls * down into the PIC-specific version for the actual * hardware disable after having gotten the irq * controller lock. */ /** * disable_irq_nosync - disable an irq without waiting * @irq: Interrupt to disable * * Disable the selected interrupt line. Disables of an interrupt * stack. Unlike disable_irq(), this function does not ensure existing * instances of the IRQ handler have completed before returning. * * This function may be called from IRQ context. */ inline void disable_irq_nosync(unsigned int irq) { irq_desc_t *desc = irq_desc + irq; unsigned long flags; spin_lock_irqsave(&desc->lock, flags); if (!desc->depth++) { desc->status |= IRQ_DISABLED; desc->handler->disable(irq); } spin_unlock_irqrestore(&desc->lock, flags); } #ifdef CONFIG_SMP inline void synchronize_irq(unsigned int irq) { /* is there anything to synchronize with? */ if (!irq_desc[irq].action) return; while (irq_desc[irq].status & IRQ_INPROGRESS) cpu_relax(); } #endif /** * disable_irq - disable an irq and wait for completion * @irq: Interrupt to disable * * Disable the selected interrupt line. Disables of an interrupt * stack. That is for two disables you need two enables. This * function waits for any pending IRQ handlers for this interrupt * to complete before returning. If you use this function while * holding a resource the IRQ handler may need you will deadlock. * * This function may be called - with care - from IRQ context. */ void disable_irq(unsigned int irq) { disable_irq_nosync(irq); synchronize_irq(irq); } /** * enable_irq - enable interrupt handling on an irq * @irq: Interrupt to enable * * Re-enables the processing of interrupts on this IRQ line * providing no disable_irq calls are now in effect. * * This function may be called from IRQ context. */ void enable_irq(unsigned int irq) { irq_desc_t *desc = irq_desc + irq; unsigned long flags; spin_lock_irqsave(&desc->lock, flags); switch (desc->depth) { case 1: { unsigned int status = desc->status & ~IRQ_DISABLED; desc->status = status; if ((status & (IRQ_PENDING | IRQ_REPLAY)) == IRQ_PENDING) { desc->status = status | IRQ_REPLAY; hw_resend_irq(desc->handler,irq); } desc->handler->enable(irq); /* fall-through */ } default: desc->depth--; break; case 0: printk(KERN_ERR "enable_irq() unbalanced from %p\n", __builtin_return_address(0)); } spin_unlock_irqrestore(&desc->lock, flags); } /* * do_IRQ handles all normal device IRQ's (the special * SMP cross-CPU interrupts have their own specific * handlers). */ unsigned int do_IRQ(int irq, union uml_pt_regs *regs) { /* * 0 return value means that this irq is already being * handled by some other CPU. (or is disabled) */ int cpu = smp_processor_id(); irq_desc_t *desc = irq_desc + irq; struct irqaction * action; unsigned int status; irq_enter(); kstat_cpu(cpu).irqs[irq]++; spin_lock(&desc->lock); desc->handler->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 (!(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 (!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 (;;) { spin_unlock(&desc->lock); handle_IRQ_event(irq, (struct pt_regs *) regs, action); spin_lock(&desc->lock); if (!(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->handler->end(irq); spin_unlock(&desc->lock); irq_exit(); return 1; } /** * 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, void (*handler)(int, void *, struct pt_regs *), unsigned long irqflags, const char * devname, void *dev_id) { int retval; struct irqaction * action; #if 1 /* * Sanity-check: shared interrupts should REALLY 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 & SA_SHIRQ) { if (!dev_id) printk(KERN_ERR "Bad boy: %s (at 0x%x) called us " "without a dev_id!\n", devname, (&irq)[-1]); } #endif if (irq >= NR_IRQS) return -EINVAL; if (!handler) return -EINVAL; action = (struct irqaction *) kmalloc(sizeof(struct irqaction), GFP_KERNEL); if (!action) return -ENOMEM; action->handler = handler; action->flags = irqflags; 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); int um_request_irq(unsigned int irq, int fd, int type, void (*handler)(int, void *, struct pt_regs *), unsigned long irqflags, const char * devname, void *dev_id) { int retval; retval = request_irq(irq, handler, irqflags, devname, dev_id); if(retval) return(retval); return(activate_fd(irq, fd, type, dev_id)); } /* this was setup_x86_irq but it seems pretty generic */ int setup_irq(unsigned int irq, struct irqaction * new) { int shared = 0; unsigned long flags; struct irqaction *old, **p; irq_desc_t *desc = irq_desc + irq; /* * 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 */ spin_lock_irqsave(&desc->lock,flags); p = &desc->action; if ((old = *p) != NULL) { /* Can't share interrupts unless both agree to */ if (!(old->flags & new->flags & SA_SHIRQ)) { spin_unlock_irqrestore(&desc->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->depth = 0; desc->status &= ~IRQ_DISABLED; desc->handler->startup(irq); } spin_unlock_irqrestore(&desc->lock,flags); register_irq_proc(irq); return 0; } /** * 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. The function * does not return until any executing interrupts for this IRQ * have completed. * * This function may be called from interrupt context. * * Bugs: Attempting to free an irq in a handler for the same irq hangs * the machine. */ void free_irq(unsigned int irq, void *dev_id) { irq_desc_t *desc; struct irqaction **p; unsigned long flags; if (irq >= NR_IRQS) return; desc = irq_desc + irq; spin_lock_irqsave(&desc->lock,flags); p = &desc->action; for (;;) { struct irqaction * action = *p; if (action) { struct irqaction **pp = p; p = &action->next; if (action->dev_id != dev_id) continue; /* Found it - now remove it from the list of entries */ *pp = action->next; if (!desc->action) { desc->status |= IRQ_DISABLED; desc->handler->shutdown(irq); } free_irq_by_irq_and_dev(irq, dev_id); spin_unlock_irqrestore(&desc->lock,flags); /* Wait to make sure it's not being used on another CPU */ synchronize_irq(irq); kfree(action); return; } printk(KERN_ERR "Trying to free free IRQ%d\n",irq); spin_unlock_irqrestore(&desc->lock,flags); return; } } EXPORT_SYMBOL(free_irq); /* These are initialized by sysctl_init, which is called from init/main.c */ static struct proc_dir_entry * root_irq_dir; static struct proc_dir_entry * irq_dir [NR_IRQS]; static struct proc_dir_entry * smp_affinity_entry [NR_IRQS]; /* These are read and written as longs, so a read won't see a partial write * even during a race. */ static cpumask_t irq_affinity [NR_IRQS] = { [0 ... NR_IRQS-1] = CPU_MASK_ALL }; static int irq_affinity_read_proc (char *page, char **start, off_t off, int count, int *eof, void *data) { int len = cpumask_scnprintf(page, count, irq_affinity[(long)data]); if (count - len < 2) return -EINVAL; len += sprintf(page + len, "\n"); return len; } static int irq_affinity_write_proc (struct file *file, const char *buffer, unsigned long count, void *data) { int irq = (long) data, full_count = count, err; cpumask_t new_value, tmp; if (!irq_desc[irq].handler->set_affinity) return -EIO; err = cpumask_parse(buffer, count, new_value); #ifdef CONFIG_SMP /* * Do not allow disabling IRQs completely - it's a too easy * way to make the system unusable accidentally :-) At least * one online CPU still has to be targeted. */ cpus_and(tmp, new_value, cpu_online_map); if (cpus_empty(tmp)) return -EINVAL; #endif irq_affinity[irq] = new_value; irq_desc[irq].handler->set_affinity(irq, new_value); return full_count; } static int prof_cpu_mask_read_proc (char *page, char **start, off_t off, int count, int *eof, void *data) { int len = cpumask_scnprintf(page, count, *(cpumask_t *)data); if (count - len < 2) return -EINVAL; len += sprintf(page + len, "\n"); return len; } static int prof_cpu_mask_write_proc (struct file *file, const char *buffer, unsigned long count, void *data) { cpumask_t *mask = (cpumask_t *)data, new_value; unsigned long full_count = count, err; err = cpumask_parse(buffer, count, new_value); if (err) return err; *mask = new_value; return full_count; } #define MAX_NAMELEN 10 static void register_irq_proc (unsigned int irq) { struct proc_dir_entry *entry; char name [MAX_NAMELEN]; if (!root_irq_dir || (irq_desc[irq].handler == &no_irq_type) || irq_dir[irq]) return; memset(name, 0, MAX_NAMELEN); sprintf(name, "%d", irq); /* create /proc/irq/1234 */ irq_dir[irq] = proc_mkdir(name, root_irq_dir); /* create /proc/irq/1234/smp_affinity */ entry = create_proc_entry("smp_affinity", 0600, irq_dir[irq]); entry->nlink = 1; entry->data = (void *)(long)irq; entry->read_proc = irq_affinity_read_proc; entry->write_proc = irq_affinity_write_proc; smp_affinity_entry[irq] = entry; } /* Read and written as a long */ cpumask_t prof_cpu_mask = CPU_MASK_ALL; void __init init_irq_proc (void) { struct proc_dir_entry *entry; int i; /* create /proc/irq */ root_irq_dir = proc_mkdir("irq", 0); /* create /proc/irq/prof_cpu_mask */ entry = create_proc_entry("prof_cpu_mask", 0600, root_irq_dir); entry->nlink = 1; entry->data = (void *)&prof_cpu_mask; entry->read_proc = prof_cpu_mask_read_proc; entry->write_proc = prof_cpu_mask_write_proc; /* * Create entries for all existing IRQs. */ for (i = 0; i < NR_IRQS; i++) register_irq_proc(i); } static spinlock_t irq_spinlock = SPIN_LOCK_UNLOCKED; unsigned long irq_lock(void) { unsigned long flags; spin_lock_irqsave(&irq_spinlock, flags); return(flags); } void irq_unlock(unsigned long flags) { spin_unlock_irqrestore(&irq_spinlock, flags); } unsigned long probe_irq_on(void) { return(0); } EXPORT_SYMBOL(probe_irq_on); int probe_irq_off(unsigned long val) { return(0); } EXPORT_SYMBOL(probe_irq_off); static unsigned int startup_SIGIO_irq(unsigned int irq) { return(0); } static void shutdown_SIGIO_irq(unsigned int irq) { } static void enable_SIGIO_irq(unsigned int irq) { } static void disable_SIGIO_irq(unsigned int irq) { } static void mask_and_ack_SIGIO(unsigned int irq) { } static void end_SIGIO_irq(unsigned int irq) { } static unsigned int startup_SIGVTALRM_irq(unsigned int irq) { return(0); } static void shutdown_SIGVTALRM_irq(unsigned int irq) { } static void enable_SIGVTALRM_irq(unsigned int irq) { } static void disable_SIGVTALRM_irq(unsigned int irq) { } static void mask_and_ack_SIGVTALRM(unsigned int irq) { } static void end_SIGVTALRM_irq(unsigned int irq) { } static struct hw_interrupt_type SIGIO_irq_type = { "SIGIO", startup_SIGIO_irq, shutdown_SIGIO_irq, enable_SIGIO_irq, disable_SIGIO_irq, mask_and_ack_SIGIO, end_SIGIO_irq, NULL }; static struct hw_interrupt_type SIGVTALRM_irq_type = { "SIGVTALRM", startup_SIGVTALRM_irq, shutdown_SIGVTALRM_irq, enable_SIGVTALRM_irq, disable_SIGVTALRM_irq, mask_and_ack_SIGVTALRM, end_SIGVTALRM_irq, NULL }; void __init init_IRQ(void) { int i; irq_desc[TIMER_IRQ].status = IRQ_DISABLED; irq_desc[TIMER_IRQ].action = 0; irq_desc[TIMER_IRQ].depth = 1; irq_desc[TIMER_IRQ].handler = &SIGVTALRM_irq_type; enable_irq(TIMER_IRQ); for(i=1;i