kernel-ark/arch/arm/kernel/irq.c
Russell King 8749af6821 [PATCH] ARM: Generic Dynamic Tick Timer support for ARM, take 4
This patch adds support for Dynamic Tick Timer for ARM. Dynamic Tick is
also known as VST (Variable Scheduling Timeouts).

Dynamic Tick has been in use in the OMAP tree since last October.  The
patch is not intrusive, and does not do anything unless CONFIG_NO_IDLE_HZ
is defined.  This patch has the following fixed based on comments from
RMK:
- Time is updated before calling interrupt handlers.
- Added new interrupt flag SA_TIMER to avoid duplicate timer interrupts
- Moved struct dyn_tick_timer to time.h until we at some point probably
  have an arch independent dyn-tick.h
- Cleaned up testing for DYN_TICK_ENABLED in irq.c

 I've cleaned up this patch to fix some remaining issues:
 - Call the timer tick handler with irqs disabled, as it would be from
   a normal interrupt
 - if we have a dyn_tick, we better implement all methods.
 - generic timer_dyn_reprogram() call, to be called before sleeping
 - added command line option - "dyntick=" to allow boot-time control
   of this feature
    -- rmk

Signed-off-by: Tony Lindgren
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2005-06-25 19:39:45 +01:00

1053 lines
24 KiB
C

/*
* 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->wake)
desc->chip->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->wake)
desc->chip->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);
#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(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, 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->type) {
spin_lock_irqsave(&irq_controller_lock, flags);
ret = desc->chip->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 */
if (!(old->flags & new->flags & SA_SHIRQ)) {
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 (!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->type)
irq_desc[i].chip->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", 0);
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;
extern void init_dma(void);
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();
init_dma();
}
static int __init noirqdebug_setup(char *str)
{
noirqdebug = 1;
return 1;
}
__setup("noirqdebug", noirqdebug_setup);