* 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/irq.h>
#include <linux/ptrace.h>
#include <linux/slab.h>
#include <linux/random.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.
*/
#define irq_finish(irq) do { } while (0)
#endif
-void (*init_arch_irq)(void) __initdata = NULL;
-unsigned long irq_err_count;
+/*
+ * 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)
{
}
if (i < NR_IRQS) {
- spin_lock_irqsave(&irq_desc[i].lock, flags);
- action = irq_desc[i].action;
+ 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, " %10s", irq_desc[i].chip->name ? : "-");
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_desc[i].lock, flags);
+ spin_unlock_irqrestore(&irq_controller_lock, flags);
} else if (i == NR_IRQS) {
#ifdef CONFIG_ARCH_ACORN
show_fiq_list(p, v);
return 0;
}
-/* Handle bad interrupts */
-static struct irq_desc bad_irq_desc = {
- .handle_irq = handle_bad_irq,
- .lock = SPIN_LOCK_UNLOCKED
-};
+/*
+ * 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
desc = &bad_irq_desc;
irq_enter();
-
+ spin_lock(&irq_controller_lock);
desc_handle_irq(irq, desc, regs);
- /* AT91 specific workaround */
+ /*
+ * 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;
}
desc = irq_desc + irq;
- spin_lock_irqsave(&desc->lock, flags);
- desc->status |= IRQ_NOREQUEST | IRQ_NOPROBE | IRQ_NOAUTOEN;
- if (iflags & IRQF_VALID)
- desc->status &= ~IRQ_NOREQUEST;
- if (iflags & IRQF_PROBE)
- desc->status &= ~IRQ_NOPROBE;
- if (!(iflags & IRQF_NOAUTOEN))
- desc->status &= ~IRQ_NOAUTOEN;
- spin_unlock_irqrestore(&desc->lock, flags);
+ 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);
}
-void __init init_IRQ(void)
+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;
- for (irq = 0; irq < NR_IRQS; irq++)
- irq_desc[irq].status |= IRQ_NOREQUEST | IRQ_DELAYED_DISABLE |
- IRQ_NOPROBE;
+ 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();
}
-#ifdef CONFIG_HOTPLUG_CPU
-
-static void route_irq(struct irqdesc *desc, unsigned int irq, unsigned int cpu)
+static int __init noirqdebug_setup(char *str)
{
- pr_debug("IRQ%u: moving from cpu%u to cpu%u\n", irq, desc->cpu, cpu);
-
- spin_lock_irq(&desc->lock);
- desc->chip->set_affinity(irq, cpumask_of_cpu(cpu));
- spin_unlock_irq(&desc->lock);
+ 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
git://git.onelab.eu / linux-2.6.git / blobdiff