blob: 2d5896b36181fa8ceb9636240b8abd13a2a0992e [file] [log] [blame]
/*
* 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 (noirqdebug)
return;
if (ret != IRQ_HANDLED && ret != IRQ_NONE) {
if (!count)
return;
count--;
printk("irq%u: bogus retval mask %x\n", irq, ret);
} else {
desc->irqs_unhandled++;
if (desc->irqs_unhandled <= 99900)
return;
desc->irqs_unhandled = 0;
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 */