/*
* arch/ppc/kernel/irq.c
*
* Derived from arch/i386/kernel/irq.c
* Copyright (C) 1992 Linus Torvalds
* Adapted from arch/i386 by Gary Thomas
* Copyright (C) 1995-1996 Gary Thomas (gdt@linuxppc.org)
* Updated and modified by Cort Dougan (cort@cs.nmt.edu)
* Copyright (C) 1996 Cort Dougan
* Adapted for Power Macintosh by Paul Mackerras
* Copyright (C) 1996 Paul Mackerras (paulus@cs.anu.edu.au)
* Amiga/APUS changes by Jesper Skov (jskov@cygnus.co.uk).
*
* This program is free software; you can redistribute it and/or
* modify it under the terms of the GNU General Public License
* as published by the Free Software Foundation; either version
* 2 of the License, or (at your option) any later version.
*
* 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.
*/
#include <linux/errno.h>
#include <linux/module.h>
#include <linux/threads.h>
#include <linux/kernel_stat.h>
#include <linux/signal.h>
#include <linux/sched.h>
#include <linux/ioport.h>
#include <linux/interrupt.h>
#include <linux/timex.h>
#include <linux/config.h>
#include <linux/init.h>
#include <linux/slab.h>
#include <linux/pci.h>
#include <linux/delay.h>
#include <linux/irq.h>
#include <linux/proc_fs.h>
#include <linux/random.h>
#include <linux/kallsyms.h>
#include <asm/uaccess.h>
#include <asm/bitops.h>
#include <asm/system.h>
#include <asm/io.h>
#include <asm/pgtable.h>
#include <asm/irq.h>
#include <asm/cache.h>
#include <asm/prom.h>
#include <asm/ptrace.h>
#include <asm/iSeries/LparData.h>
#include <asm/machdep.h>
#include <asm/paca.h>
#ifdef CONFIG_SMP
extern void iSeries_smp_message_recv( struct pt_regs * );
#endif
static void register_irq_proc (unsigned int irq);
irq_desc_t irq_desc[NR_IRQS] __cacheline_aligned = {
[0 ... NR_IRQS-1] = {
.lock = SPIN_LOCK_UNLOCKED
}
};
int ppc_spurious_interrupts = 0;
unsigned long lpEvent_count = 0;
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 | IRQ_AUTODETECT | IRQ_WAITING | IRQ_INPROGRESS);
if (desc->handler && desc->handler->startup)
desc->handler->startup(irq);
unmask_irq(irq);
}
spin_unlock_irqrestore(&desc->lock,flags);
register_irq_proc(irq);
return 0;
}
#ifdef CONFIG_SMP
inline void synchronize_irq(unsigned int irq)
{
while (irq_desc[irq].status & IRQ_INPROGRESS)
cpu_relax();
}
EXPORT_SYMBOL(synchronize_irq);
#endif /* CONFIG_SMP */
/* XXX Make this into free_irq() - Anton */
/* This could be promoted to a real free_irq() ... */
static int
do_free_irq(int irq, void* dev_id)
{
irq_desc_t *desc;
struct irqaction **p;
unsigned long flags;
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;
mask_irq(irq);
}
spin_unlock_irqrestore(&desc->lock,flags);
/* Wait to make sure it's not being used on another CPU */
synchronize_irq(irq);
kfree(action);
return 0;
}
printk("Trying to free free IRQ%d\n",irq);
spin_unlock_irqrestore(&desc->lock,flags);
break;
}
return -ENOENT;
}
int request_irq(unsigned int irq,
irqreturn_t (*handler)(int, void *, struct pt_regs *),
unsigned long irqflags, const char * devname, void *dev_id)
{
struct irqaction *action;
int retval;
if (irq >= NR_IRQS)
return -EINVAL;
if (!handler)
/* We could implement really free_irq() instead of that... */
return do_free_irq(irq, dev_id);
action = (struct irqaction *)
kmalloc(sizeof(struct irqaction), GFP_KERNEL);
if (!action) {
printk(KERN_ERR "kmalloc() failed for irq %d !\n", irq);
return -ENOMEM;
}
action->handler = handler;
action->flags = irqflags;
action->mask = 0;
action->name = devname;
action->dev_id = dev_id;
action->next = NULL;
retval = setup_irq(irq, action);
if (retval)
kfree(action);
return 0;
}
EXPORT_SYMBOL(request_irq);
void free_irq(unsigned int irq, void *dev_id)
{
request_irq(irq, NULL, 0, NULL, dev_id);
}
EXPORT_SYMBOL(free_irq);
/*
* 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++) {
if (!(desc->status & IRQ_PER_CPU))
desc->status |= IRQ_DISABLED;
mask_irq(irq);
}
spin_unlock_irqrestore(&desc->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. 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)
{
irq_desc_t *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
* 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);
}
unmask_irq(irq);
/* fall-through */
}
default:
desc->depth--;
break;
case 0:
printk("enable_irq(%u) unbalanced from %p\n", irq,
__builtin_return_address(0));
}
spin_unlock_irqrestore(&desc->lock, flags);
}
EXPORT_SYMBOL(enable_irq);
int show_interrupts(struct seq_file *p, void *v)
{
int i = *(loff_t *) v, j;
struct irqaction * action;
unsigned long flags;
if (i == 0) {
seq_printf(p, " ");
for (j=0; j<NR_CPUS; j++) {
if (cpu_online(j))
seq_printf(p, "CPU%d ",j);
}
seq_putc(p, '\n');
}
if (i < NR_IRQS) {
spin_lock_irqsave(&irq_desc[i].lock, flags);
action = irq_desc[i].action;
if (!action || !action->handler)
goto skip;
seq_printf(p, "%3d: ", i);
#ifdef CONFIG_SMP
for (j = 0; j < NR_CPUS; j++) {
if (cpu_online(j))
seq_printf(p, "%10u ", kstat_cpu(j).irqs[i]);
}
#else
seq_printf(p, "%10u ", kstat_irqs(i));
#endif /* CONFIG_SMP */
if (irq_desc[i].handler)
seq_printf(p, " %s ", irq_desc[i].handler->typename );
else
seq_printf(p, " None ");
seq_printf(p, "%s", (irq_desc[i].status & IRQ_LEVEL) ? "Level " : "Edge ");
seq_printf(p, " %s",action->name);
for (action=action->next; action; action = action->next)
seq_printf(p, ", %s", action->name);
seq_putc(p, '\n');
skip:
spin_unlock_irqrestore(&irq_desc[i].lock, flags);
} else if (i == NR_IRQS)
seq_printf(p, "BAD: %10u\n", ppc_spurious_interrupts);
return 0;
}
static inline int handle_irq_event(int irq, struct pt_regs *regs,
struct irqaction *action)
{
int status = 0;
int retval = 0;
#ifndef CONFIG_PPC_ISERIES
if (!(action->flags & SA_INTERRUPT))
local_irq_enable();
#endif
do {
status |= action->flags;
retval |= action->handler(irq, action->dev_id, regs);
action = action->next;
} while (action);
if (status & SA_SAMPLE_RANDOM)
add_interrupt_randomness(irq);
#ifndef CONFIG_PPC_ISERIES
local_irq_disable();
#endif
return retval;
}
static void __report_bad_irq(int irq, irq_desc_t *desc, irqreturn_t action_ret)
{
struct irqaction *action;
if (action_ret != IRQ_HANDLED && action_ret != IRQ_NONE) {
printk(KERN_ERR "irq event %d: bogus return value %x\n",
irq, action_ret);
} else {
printk(KERN_ERR "irq %d: nobody cared!\n", irq);
}
dump_stack();
printk(KERN_ERR "handlers:\n");
action = desc->action;
do {
printk(KERN_ERR "[<%p>]", action->handler);
print_symbol(" (%s)",
(unsigned long)action->handler);
printk("\n");
action = action->next;
} while (action);
}
static void report_bad_irq(int irq, irq_desc_t *desc, irqreturn_t action_ret)
{
static int count = 100;
if (count) {
count--;
__report_bad_irq(irq, desc, action_ret);
}
}
static int noirqdebug;
static int __init noirqdebug_setup(char *str)
{
noirqdebug = 1;
printk("IRQ lockup detection disabled\n");
return 1;
}
__setup("noirqdebug", noirqdebug_setup);
/*
* If 99,900 of the previous 100,000 interrupts have not been handled then
* assume that the IRQ is stuck in some manner. Drop a diagnostic and try to
* turn the IRQ off.
*
* (The other 100-of-100,000 interrupts may have been a correctly-functioning
* device sharing an IRQ with the failing one)
*
* Called under desc->lock
*/
static void note_interrupt(int irq, irq_desc_t *desc, irqreturn_t action_ret)
{
if (action_ret != IRQ_HANDLED) {
desc->irqs_unhandled++;
if (action_ret != IRQ_NONE)
report_bad_irq(irq, desc, action_ret);
}
desc->irq_count++;
if (desc->irq_count < 100000)
return;
desc->irq_count = 0;
if (desc->irqs_unhandled > 99900) {
/*
* The interrupt is stuck
*/
__report_bad_irq(irq, desc, action_ret);
/*
* Now kill the IRQ
*/
printk(KERN_EMERG "Disabling IRQ #%d\n", irq);
desc->status |= IRQ_DISABLED;
desc->handler->disable(irq);
}
desc->irqs_unhandled = 0;
}
/*
* Eventually, this should take an array of interrupts and an array size
* so it can dispatch multiple interrupts.
*/
void ppc_irq_dispatch_handler(struct pt_regs *regs, int irq)
{
int status;
struct irqaction *action;
int cpu = smp_processor_id();
irq_desc_t *desc = irq_desc + irq;
irqreturn_t action_ret;
kstat_cpu(cpu).irqs[irq]++;
if (desc->status & IRQ_PER_CPU) {
/* no locking required for CPU-local interrupts: */
ack_irq(irq);
action_ret = handle_irq_event(irq, regs, desc->action);
desc->handler->end(irq);
return;
}
spin_lock(&desc->lock);
ack_irq(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 (likely(!(status & (IRQ_DISABLED | IRQ_INPROGRESS)))) {
action = desc->action;
if (!action || !action->handler) {
ppc_spurious_interrupts++;
printk(KERN_DEBUG "Unhandled interrupt %x, disabled\n", irq);
/* We can't call disable_irq here, it would deadlock */
if (!desc->depth)
desc->depth = 1;
desc->status |= IRQ_DISABLED;
/* This is not a real spurrious interrupt, we
* have to eoi it, so we jump to out
*/
mask_irq(irq);
goto out;
}
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 (unlikely(!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);
action_ret = handle_irq_event(irq, regs, action);
spin_lock(&desc->lock);
if (!noirqdebug)
note_interrupt(irq, desc, action_ret);
if (likely(!(desc->status & IRQ_PENDING)))
break;
desc->status &= ~IRQ_PENDING;
}
out:
desc->status &= ~IRQ_INPROGRESS;
/*
* The ->end() handler has to deal with interrupts which got
* disabled while the handler was running.
*/
if (irq_desc[irq].handler) {
if (irq_desc[irq].handler->end)
irq_desc[irq].handler->end(irq);
else if (irq_desc[irq].handler->enable)
irq_desc[irq].handler->enable(irq);
}
spin_unlock(&desc->lock);
}
#ifdef CONFIG_PPC_ISERIES
int do_IRQ(struct pt_regs *regs)
{
struct paca_struct *lpaca;
struct ItLpQueue *lpq;
irq_enter();
#ifdef CONFIG_DEBUG_STACKOVERFLOW
/* Debugging check for stack overflow: is there less than 4KB free? */
{
long sp;
sp = __get_SP() & (THREAD_SIZE-1);
if (unlikely(sp < (sizeof(struct thread_info) + 4096))) {
printk("do_IRQ: stack overflow: %ld\n",
sp - sizeof(struct thread_info));
dump_stack();
}
}
#endif
lpaca = get_paca();
#ifdef CONFIG_SMP
if (lpaca->xLpPaca.xIntDword.xFields.xIpiCnt) {
lpaca->xLpPaca.xIntDword.xFields.xIpiCnt = 0;
iSeries_smp_message_recv(regs);
}
#endif /* CONFIG_SMP */
lpq = lpaca->lpQueuePtr;
if (lpq && ItLpQueue_isLpIntPending(lpq))
lpEvent_count += ItLpQueue_process(lpq, regs);
irq_exit();
if (lpaca->xLpPaca.xIntDword.xFields.xDecrInt) {
lpaca->xLpPaca.xIntDword.xFields.xDecrInt = 0;
/* Signal a fake decrementer interrupt */
timer_interrupt(regs);
}
return 1; /* lets ret_from_int know we can do checks */
}
#else /* CONFIG_PPC_ISERIES */
int do_IRQ(struct pt_regs *regs)
{
int irq, first = 1;
irq_enter();
/*
* Every arch is required to implement ppc_md.get_irq.
* This function will either return an irq number or -1 to
* indicate there are no more pending. But the first time
* through the loop this means there wasn't an IRQ pending.
* The value -2 is for buggy hardware and means that this IRQ
* has already been handled. -- Tom
*/
while ((irq = ppc_md.get_irq(regs)) >= 0) {
ppc_irq_dispatch_handler(regs, irq);
first = 0;
}
if (irq != -2 && first)
/* That's not SMP safe ... but who cares ? */
ppc_spurious_interrupts++;
irq_exit();
return 1; /* lets ret_from_int know we can do checks */
}
#endif /* CONFIG_PPC_ISERIES */
unsigned long probe_irq_on (void)
{
return 0;
}
EXPORT_SYMBOL(probe_irq_on);
int probe_irq_off (unsigned long irqs)
{
return 0;
}
EXPORT_SYMBOL(probe_irq_off);
unsigned int probe_irq_mask(unsigned long irqs)
{
return 0;
}
void __init init_IRQ(void)
{
static int once = 0;
if (once)
return;
once++;
ppc_md.init_IRQ();
}
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];
#ifdef CONFIG_IRQ_ALL_CPUS
cpumask_t irq_affinity [NR_IRQS] = { [0 ... NR_IRQS-1] = CPU_MASK_ALL };
#else /* CONFIG_IRQ_ALL_CPUS */
cpumask_t irq_affinity [NR_IRQS] = { [0 ... NR_IRQS-1] = CPU_MASK_NONE };
#endif /* CONFIG_IRQ_ALL_CPUS */
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;
cpumask_t allcpus = CPU_MASK_ALL;
if (!irq_desc[irq].handler->set_affinity)
return -EIO;
err = cpumask_parse(buffer, count, new_value);
if (err)
return err;
/*
* We check for CPU_MASK_ALL in xics to send irqs to all cpus.
* In some cases CPU_MASK_ALL is smaller than the cpumask (eg
* NR_CPUS == 32 and cpumask is a long), so we mask it here to
* be consistent.
*/
cpus_and(new_value, new_value, allcpus);
/*
* 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;
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 __user *buffer,
unsigned long count, void *data)
{
cpumask_t *mask = (cpumask_t *)data;
unsigned long full_count = count, err;
cpumask_t new_value;
err = cpumask_parse(buffer, count, new_value);
if (err)
return err;
*mask = new_value;
#ifdef CONFIG_PPC_ISERIES
{
unsigned i;
for (i=0; i<NR_CPUS; ++i) {
if ( paca[i].prof_buffer && (new_value & 1) )
paca[i].prof_enabled = 1;
else
paca[i].prof_enabled = 0;
new_value >>= 1;
}
}
#endif
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 == NULL) || 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]);
if (entry) {
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;
}
unsigned long prof_cpu_mask = -1;
void 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);
if (!entry)
return;
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++) {
if (irq_desc[i].handler == NULL)
continue;
register_irq_proc(i);
}
}
irqreturn_t no_action(int irq, void *dev, struct pt_regs *regs)
{
return IRQ_NONE;
}
#ifndef CONFIG_PPC_ISERIES
/*
* Virtual IRQ mapping code, used on systems with XICS interrupt controllers.
*/
#define UNDEFINED_IRQ 0xffffffff
unsigned int virt_irq_to_real_map[NR_IRQS];
/*
* Don't use virtual irqs 0, 1, 2 for devices.
* The pcnet32 driver considers interrupt numbers < 2 to be invalid,
* and 2 is the XICS IPI interrupt.
* We limit virtual irqs to 17 less than NR_IRQS so that when we
* offset them by 16 (to reserve the first 16 for ISA interrupts)
* we don't end up with an interrupt number >= NR_IRQS.
*/
#define MIN_VIRT_IRQ 3
#define MAX_VIRT_IRQ (NR_IRQS - NUM_8259_INTERRUPTS - 1)
#define NR_VIRT_IRQS (MAX_VIRT_IRQ - MIN_VIRT_IRQ + 1)
void
virt_irq_init(void)
{
int i;
for (i = 0; i < NR_IRQS; i++)
virt_irq_to_real_map[i] = UNDEFINED_IRQ;
}
/* Create a mapping for a real_irq if it doesn't already exist.
* Return the virtual irq as a convenience.
*/
int virt_irq_create_mapping(unsigned int real_irq)
{
unsigned int virq, first_virq;
static int warned;
if (naca->interrupt_controller == IC_OPEN_PIC)
return real_irq; /* no mapping for openpic (for now) */
/* don't map interrupts < MIN_VIRT_IRQ */
if (real_irq < MIN_VIRT_IRQ) {
virt_irq_to_real_map[real_irq] = real_irq;
return real_irq;
}
/* map to a number between MIN_VIRT_IRQ and MAX_VIRT_IRQ */
virq = real_irq;
if (virq > MAX_VIRT_IRQ)
virq = (virq % NR_VIRT_IRQS) + MIN_VIRT_IRQ;
/* search for this number or a free slot */
first_virq = virq;
while (virt_irq_to_real_map[virq] != UNDEFINED_IRQ) {
if (virt_irq_to_real_map[virq] == real_irq)
return virq;
if (++virq > MAX_VIRT_IRQ)
virq = MIN_VIRT_IRQ;
if (virq == first_virq)
goto nospace; /* oops, no free slots */
}
virt_irq_to_real_map[virq] = real_irq;
return virq;
nospace:
if (!warned) {
printk(KERN_CRIT "Interrupt table is full\n");
printk(KERN_CRIT "Increase NR_IRQS (currently %d) "
"in your kernel sources and rebuild.\n", NR_IRQS);
warned = 1;
}
return NO_IRQ;
}
/*
* In most cases will get a hit on the very first slot checked in the
* virt_irq_to_real_map. Only when there are a large number of
* IRQs will this be expensive.
*/
unsigned int real_irq_to_virt_slowpath(unsigned int real_irq)
{
unsigned int virq;
unsigned int first_virq;
virq = real_irq;
if (virq > MAX_VIRT_IRQ)
virq = (virq % NR_VIRT_IRQS) + MIN_VIRT_IRQ;
first_virq = virq;
do {
if (virt_irq_to_real_map[virq] == real_irq)
return virq;
virq++;
if (virq >= MAX_VIRT_IRQ)
virq = 0;
} while (first_virq != virq);
return NO_IRQ;
}
#endif
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