#include "irq_user.h"
#include "irq_kern.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
+};
/*
* Generic, controller-independent functions:
skip:
spin_unlock_irqrestore(&irq_desc[i].lock, flags);
} else if (i == NR_IRQS) {
+ seq_printf(p, "NMI: ");
+ for (j = 0; j < NR_CPUS; j++)
+ if (cpu_online(j))
+ seq_printf(p, "%10u ", nmi_count(j));
seq_putc(p, '\n');
}
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 */
+ int ret, retval = 0;
+
+ if (!(action->flags & SA_INTERRUPT))
+ local_irq_enable();
+
+ 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);
+
+ local_irq_disable();
+
+ return retval;
+}
+
+/*
+ * 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)
+ */
+ irq_desc_t *desc = irq_desc + irq;
+ struct irqaction * action;
+ unsigned int status;
+
+ irq_enter();
+ kstat_this_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,
+ irqreturn_t (*handler)(int, void *, struct pt_regs *),
+ unsigned long irqflags,
+ const char * devname,
+ void *dev_id)
{
- irq_enter();
- __do_IRQ(irq, (struct pt_regs *) regs);
- irq_exit();
- return 1;
+ 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,
irqreturn_t (*handler)(int, void *, struct pt_regs *),
unsigned long irqflags, const char * devname,
EXPORT_SYMBOL(um_request_irq);
EXPORT_SYMBOL(reactivate_fd);
+/* 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;
+ old = *p;
+ if (old != 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;
+
+ if (!irq_desc[irq].handler->set_affinity)
+ return -EIO;
+
+ err = cpumask_parse(buffer, count, new_value);
+ if(err)
+ return(err);
+
+#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.
+ */
+ { cpumask_t tmp;
+ 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;
+}
+
+#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;
+}
+
+void __init init_irq_proc (void)
+{
+ int i;
+
+ /* create /proc/irq */
+ root_irq_dir = proc_mkdir("irq", 0);
+
+ /* create /proc/irq/prof_cpu_mask */
+ create_prof_cpu_mask(root_irq_dir);
+
+ /*
+ * 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)
spin_unlock_irqrestore(&irq_spinlock, flags);
}
-/* presently hw_interrupt_type must define (startup || enable) &&
- * disable && end */
-static void dummy(unsigned int irq)
+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 = {
- .typename = "SIGIO",
- .disable = dummy,
- .enable = dummy,
- .ack = dummy,
- .end = dummy
+ "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 = {
- .typename = "SIGVTALRM",
- .shutdown = dummy, /* never called */
- .disable = dummy,
- .enable = dummy,
- .ack = dummy,
- .end = dummy
+ "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)
git://git.onelab.eu / linux-2.6.git / blobdiff