/*
* linux/arch/ia64/kernel/irq.c
*
* Copyright (C) 1992, 1998 Linus Torvalds, Ingo Molnar
*
* 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.
*
* Copyright (C) Ashok Raj<ashok.raj@intel.com>, Intel Corporation 2004
*
* 4/14/2004: Added code to handle cpu migration and do safe irq
* migration without lossing interrupts for iosapic
* architecture.
*/
/*
* (mostly architecture independent, will move to kernel/irq.c in 2.5.)
*
* IRQs 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/errno.h>
#include <linux/module.h>
#include <linux/signal.h>
#include <linux/sched.h>
#include <linux/ioport.h>
#include <linux/interrupt.h>
#include <linux/timex.h>
#include <linux/slab.h>
#include <linux/random.h>
#include <linux/cpu.h>
#include <linux/ctype.h>
#include <linux/smp_lock.h>
#include <linux/init.h>
#include <linux/kernel_stat.h>
#include <linux/irq.h>
#include <linux/proc_fs.h>
#include <linux/seq_file.h>
#include <linux/kallsyms.h>
#include <linux/notifier.h>
#include <asm/atomic.h>
#include <asm/cpu.h>
#include <asm/io.h>
#include <asm/smp.h>
#include <asm/system.h>
#include <asm/bitops.h>
#include <asm/uaccess.h>
#include <asm/pgalloc.h>
#include <asm/tlbflush.h>
#include <asm/delay.h>
#include <asm/irq.h>
/*
* Linux has a controller-independent x86 interrupt architecture.
* every controller has a 'controller-template', that is used
* by the main code to do the right thing. Each driver-visible
* interrupt source is transparently wired to the appropriate
* controller. Thus drivers need not be aware of the
* interrupt-controller.
*
* Various interrupt controllers we handle: 8259 PIC, SMP IO-APIC,
* PIIX4's internal 8259 PIC and SGI's Visual Workstation Cobalt (IO-)APIC.
* (IO-APICs assumed to be messaging to Pentium local-APICs)
*
* the code is designed to be easily extended with new/different
* interrupt controllers, without having to do assembly magic.
*/
/*
* Controller mappings for all interrupt sources:
*/
irq_desc_t _irq_desc[NR_IRQS] __cacheline_aligned = {
[0 ... NR_IRQS-1] = {
.status = IRQ_DISABLED,
.handler = &no_irq_type,
.lock = SPIN_LOCK_UNLOCKED
}
};
/*
* This is updated when the user sets irq affinity via /proc
*/
cpumask_t __cacheline_aligned pending_irq_cpumask[NR_IRQS];
static unsigned long pending_irq_redir[BITS_TO_LONGS(NR_IRQS)];
#ifdef CONFIG_IA64_GENERIC
irq_desc_t * __ia64_irq_desc (unsigned int irq)
{
return _irq_desc + irq;
}
ia64_vector __ia64_irq_to_vector (unsigned int irq)
{
return (ia64_vector) irq;
}
unsigned int __ia64_local_vector_to_irq (ia64_vector vec)
{
return (unsigned int) vec;
}
#endif
static void register_irq_proc (unsigned int irq);
/*
* Special irq handlers.
*/
irqreturn_t no_action(int cpl, void *dev_id, struct pt_regs *regs)
{ return IRQ_NONE; }
/*
* Generic no controller code
*/
static void enable_none(unsigned int irq) { }
static unsigned int startup_none(unsigned int irq) { return 0; }
static void disable_none(unsigned int irq) { }
static void ack_none(unsigned int irq)
{
/*
* 'what should we do if we get a hw irq event on an illegal vector'.
* each architecture has to answer this themselves, it doesn't deserve
* a generic callback i think.
*/
#ifdef CONFIG_X86
printk(KERN_ERR "unexpected IRQ trap at vector %02x\n", irq);
#ifdef CONFIG_X86_LOCAL_APIC
/*
* Currently unexpected vectors happen only on SMP and APIC.
* We _must_ ack these because every local APIC has only N
* irq slots per priority level, and a 'hanging, unacked' IRQ
* holds up an irq slot - in excessive cases (when multiple
* unexpected vectors occur) that might lock up the APIC
* completely.
*/
ack_APIC_irq();
#endif
#endif
#ifdef CONFIG_IA64
printk(KERN_ERR "Unexpected irq vector 0x%x on CPU %u!\n", irq, smp_processor_id());
#endif
}
/* startup is the same as "enable", shutdown is same as "disable" */
#define shutdown_none disable_none
#define end_none enable_none
struct hw_interrupt_type no_irq_type = {
"none",
startup_none,
shutdown_none,
enable_none,
disable_none,
ack_none,
end_none
};
atomic_t irq_err_count;
#ifdef CONFIG_X86_IO_APIC
#ifdef APIC_MISMATCH_DEBUG
atomic_t irq_mis_count;
#endif
#endif
/*
* Generic, controller-independent functions:
*/
int show_interrupts(struct seq_file *p, void *v)
{
int j, i = *(loff_t *) v;
struct irqaction * action;
irq_desc_t *idesc;
unsigned long flags;
if (i == 0) {
seq_puts(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) {
idesc = irq_descp(i);
spin_lock_irqsave(&idesc->lock, flags);
action = idesc->action;
if (!action)
goto skip;
seq_printf(p, "%3d: ",i);
#ifndef CONFIG_SMP
seq_printf(p, "%10u ", kstat_irqs(i));
#else
for (j = 0; j < NR_CPUS; j++)
if (cpu_online(j))
seq_printf(p, "%10u ", kstat_cpu(j).irqs[i]);
#endif
seq_printf(p, " %14s", idesc->handler->typename);
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(&idesc->lock, flags);
} else if (i == NR_IRQS) {
seq_puts(p, "NMI: ");
for (j = 0; j < NR_CPUS; j++)
if (cpu_online(j))
seq_printf(p, "%10u ", nmi_count(j));
seq_putc(p, '\n');
#ifdef CONFIG_X86_LOCAL_APIC
seq_puts(p, "LOC: ");
for (j = 0; j < NR_CPUS; j++)
if (cpu_online(j))
seq_printf(p, "%10u ", irq_stat[j].apic_timer_irqs);
seq_putc(p, '\n');
#endif
seq_printf(p, "ERR: %10u\n", atomic_read(&irq_err_count));
#ifdef CONFIG_X86_IO_APIC
#ifdef APIC_MISMATCH_DEBUG
seq_printf(p, "MIS: %10u\n", atomic_read(&irq_mis_count));
#endif
#endif
}
return 0;
}
#ifdef CONFIG_SMP
inline void synchronize_irq(unsigned int irq)
{
while (irq_descp(irq)->status & IRQ_INPROGRESS)
cpu_relax();
}
EXPORT_SYMBOL(synchronize_irq);
#endif
/*
* This should really return information about whether
* we should do bottom half handling etc. Right now we
* end up _always_ checking the bottom half, which is a
* waste of time and is not what some drivers would
* prefer.
*/
int handle_IRQ_event(unsigned int irq,
struct pt_regs *regs, struct irqaction *action)
{
int status = 1; /* Force the "do bottom halves" bit */
int retval = 0;
if (!(action->flags & SA_INTERRUPT))
local_irq_enable();
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);
local_irq_disable();
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;
}
/*
* 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 and Enables are
* nested.
* 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_descp(irq);
unsigned long flags;
spin_lock_irqsave(&desc->lock, flags);
if (!desc->depth++) {
desc->status |= IRQ_DISABLED;
desc->handler->disable(irq);
}
spin_unlock_irqrestore(&desc->lock, flags);
}
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 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_descp(irq);
disable_irq_nosync(irq);
if (desc->action)
synchronize_irq(irq);
}
EXPORT_SYMBOL(disable_irq);
/**
* enable_irq - enable handling of an irq
* @irq: Interrupt to enable
*
* Undoes the effect of one call to disable_irq(). If this
* matches the last disable, processing of interrupts on this
* IRQ line is re-enabled.
*
* This function may be called from IRQ context.
*/
void enable_irq(unsigned int irq)
{
irq_desc_t *desc = irq_descp(irq);
unsigned long flags;
spin_lock_irqsave(&desc->lock, flags);
switch (desc->depth) {
case 1: {
unsigned int status = desc->status & ~IRQ_DISABLED;
desc->status = status;
if ((status & (IRQ_PENDING | IRQ_REPLAY)) == IRQ_PENDING) {
desc->status = status | IRQ_REPLAY;
hw_resend_irq(desc->handler,irq);
}
desc->handler->enable(irq);
/* fall-through */
}
default:
desc->depth--;
break;
case 0:
printk(KERN_ERR "enable_irq(%u) unbalanced from %p\n",
irq, (void *) __builtin_return_address(0));
}
spin_unlock_irqrestore(&desc->lock, flags);
}
EXPORT_SYMBOL(enable_irq);
/*
* do_IRQ handles all normal device IRQ's (the special
* SMP cross-CPU interrupts have their own specific
* handlers).
*/
unsigned int do_IRQ(unsigned long irq, struct pt_regs *regs)
{
/*
* We ack quickly, we don't want the irq controller
* thinking we're snobs just because some other CPU has
* disabled global interrupts (we have already done the
* INT_ACK cycles, it's too late to try to pretend to the
* controller that we aren't taking the interrupt).
*
* 0 return value means that this irq is already being
* handled by some other CPU. (or is disabled)
*/
irq_desc_t *desc = irq_descp(irq);
struct irqaction * action;
irqreturn_t action_ret;
unsigned int status;
int cpu;
cpu = smp_processor_id(); /* for CONFIG_PREEMPT, this must come after irq_enter()! */
kstat_cpu(cpu).irqs[irq]++;
if (desc->status & IRQ_PER_CPU) {
/* no locking required for CPU-local interrupts: */
desc->handler->ack(irq);
action_ret = handle_IRQ_event(irq, regs, desc->action);
desc->handler->end(irq);
} else {
spin_lock(&desc->lock);
desc->handler->ack(irq);
/*
* REPLAY is when Linux resends an IRQ that was dropped earlier
* WAITING is used by probe to mark irqs that are being tested
*/
status = desc->status & ~(IRQ_REPLAY | IRQ_WAITING);
status |= IRQ_PENDING; /* we _want_ to handle it */
/*
* If the IRQ is disabled for whatever reason, we cannot
* use the action we have.
*/
action = NULL;
if (likely(!(status & (IRQ_DISABLED | IRQ_INPROGRESS)))) {
action = desc->action;
status &= ~IRQ_PENDING; /* we commit to handling */
status |= IRQ_INPROGRESS; /* we are handling it */
}
desc->status = status;
/*
* If there is no IRQ handler or it was disabled, exit early.
* Since we set PENDING, if another processor is handling
* a different instance of this same irq, the other processor
* will take care of it.
*/
if (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 (!(desc->status & IRQ_PENDING))
break;
desc->status &= ~IRQ_PENDING;
}
desc->status &= ~IRQ_INPROGRESS;
out:
/*
* The ->end() handler has to deal with interrupts which got
* disabled while the handler was running.
*/
desc->handler->end(irq);
spin_unlock(&desc->lock);
}
return 1;
}
/**
* request_irq - allocate an interrupt line
* @irq: Interrupt line to allocate
* @handler: Function to be called when the IRQ occurs
* @irqflags: Interrupt type flags
* @devname: An ascii name for the claiming device
* @dev_id: A cookie passed back to the handler function
*
* This call allocates interrupt resources and enables the
* interrupt line and IRQ handling. From the point this
* call is made your handler function may be invoked. Since
* your handler function must clear any interrupt the board
* raises, you must take care both to initialise your hardware
* and to set up the interrupt handler in the right order.
*
* Dev_id must be globally unique. Normally the address of the
* device data structure is used as the cookie. Since the handler
* receives this value it makes sense to use it.
*
* If your interrupt is shared you must pass a non NULL dev_id
* as this is required when freeing the interrupt.
*
* Flags:
*
* SA_SHIRQ Interrupt is shared
*
* SA_INTERRUPT Disable local interrupts while processing
*
* SA_SAMPLE_RANDOM The interrupt can be used for entropy
*
*/
int request_irq(unsigned int irq,
irqreturn_t (*handler)(int, void *, struct pt_regs *),
unsigned long irqflags,
const char * devname,
void *dev_id)
{
int retval;
struct irqaction * action;
#if 1
/*
* Sanity-check: shared interrupts should REALLY pass in
* a real dev-ID, otherwise we'll have trouble later trying
* to figure out which interrupt is which (messes up the
* interrupt freeing logic etc).
*/
if (irqflags & SA_SHIRQ) {
if (!dev_id)
printk(KERN_ERR "Bad boy: %s called us without a dev_id!\n", devname);
}
#endif
if (irq >= NR_IRQS)
return -EINVAL;
if (!handler)
return -EINVAL;
action = (struct irqaction *)
kmalloc(sizeof(struct irqaction), GFP_ATOMIC);
if (!action)
return -ENOMEM;
action->handler = handler;
action->flags = irqflags;
cpus_clear(action->mask);
action->name = devname;
action->next = NULL;
action->dev_id = dev_id;
retval = setup_irq(irq, action);
if (retval)
kfree(action);
return retval;
}
EXPORT_SYMBOL(request_irq);
/**
* free_irq - free an interrupt
* @irq: Interrupt line to free
* @dev_id: Device identity to free
*
* Remove an interrupt handler. The handler is removed and if the
* interrupt line is no longer in use by any driver it is disabled.
* On a shared IRQ the caller must ensure the interrupt is disabled
* on the card it drives before calling this function. The function
* does not return until any executing interrupts for this IRQ
* have completed.
*
* This function must not be called from interrupt context.
*/
void free_irq(unsigned int irq, void *dev_id)
{
irq_desc_t *desc;
struct irqaction **p;
unsigned long flags;
if (irq >= NR_IRQS)
return;
desc = irq_descp(irq);
spin_lock_irqsave(&desc->lock,flags);
p = &desc->action;
for (;;) {
struct irqaction * action = *p;
if (action) {
struct irqaction **pp = p;
p = &action->next;
if (action->dev_id != dev_id)
continue;
/* Found it - now remove it from the list of entries */
*pp = action->next;
if (!desc->action) {
desc->status |= IRQ_DISABLED;
desc->handler->shutdown(irq);
}
spin_unlock_irqrestore(&desc->lock,flags);
/* Wait to make sure it's not being used on another CPU */
synchronize_irq(irq);
kfree(action);
return;
}
printk(KERN_ERR "Trying to free free IRQ%d\n",irq);
spin_unlock_irqrestore(&desc->lock,flags);
return;
}
}
EXPORT_SYMBOL(free_irq);
/*
* IRQ autodetection code..
*
* This depends on the fact that any interrupt that
* comes in on to an unassigned handler will get stuck
* with "IRQ_WAITING" cleared and the interrupt
* disabled.
*/
static DECLARE_MUTEX(probe_sem);
/**
* probe_irq_on - begin an interrupt autodetect
*
* Commence probing for an interrupt. The interrupts are scanned
* and a mask of potential interrupt lines is returned.
*
*/
unsigned long probe_irq_on(void)
{
unsigned int i;
irq_desc_t *desc;
unsigned long val;
unsigned long delay;
down(&probe_sem);
/*
* something may have generated an irq long ago and we want to
* flush such a longstanding irq before considering it as spurious.
*/
for (i = NR_IRQS-1; i > 0; i--) {
desc = irq_descp(i);
spin_lock_irq(&desc->lock);
if (!desc->action)
desc->handler->startup(i);
spin_unlock_irq(&desc->lock);
}
/* Wait for longstanding interrupts to trigger. */
for (delay = jiffies + HZ/50; time_after(delay, jiffies); )
/* about 20ms delay */ barrier();
/*
* enable any unassigned irqs
* (we must startup again here because if a longstanding irq
* happened in the previous stage, it may have masked itself)
*/
for (i = NR_IRQS-1; i > 0; i--) {
desc = irq_descp(i);
spin_lock_irq(&desc->lock);
if (!desc->action) {
desc->status |= IRQ_AUTODETECT | IRQ_WAITING;
if (desc->handler->startup(i))
desc->status |= IRQ_PENDING;
}
spin_unlock_irq(&desc->lock);
}
/*
* Wait for spurious interrupts to trigger
*/
for (delay = jiffies + HZ/10; time_after(delay, jiffies); )
/* about 100ms delay */ barrier();
/*
* Now filter out any obviously spurious interrupts
*/
val = 0;
for (i = 0; i < NR_IRQS; i++) {
irq_desc_t *desc = irq_descp(i);
unsigned int status;
spin_lock_irq(&desc->lock);
status = desc->status;
if (status & IRQ_AUTODETECT) {
/* It triggered already - consider it spurious. */
if (!(status & IRQ_WAITING)) {
desc->status = status & ~IRQ_AUTODETECT;
desc->handler->shutdown(i);
} else
if (i < 32)
val |= 1 << i;
}
spin_unlock_irq(&desc->lock);
}
return val;
}
EXPORT_SYMBOL(probe_irq_on);
/**
* probe_irq_mask - scan a bitmap of interrupt lines
* @val: mask of interrupts to consider
*
* Scan the ISA bus interrupt lines and return a bitmap of
* active interrupts. The interrupt probe logic state is then
* returned to its previous value.
*
* Note: we need to scan all the irq's even though we will
* only return ISA irq numbers - just so that we reset them
* all to a known state.
*/
unsigned int probe_irq_mask(unsigned long val)
{
int i;
unsigned int mask;
mask = 0;
for (i = 0; i < 16; i++) {
irq_desc_t *desc = irq_descp(i);
unsigned int status;
spin_lock_irq(&desc->lock);
status = desc->status;
if (status & IRQ_AUTODETECT) {
if (!(status & IRQ_WAITING))
mask |= 1 << i;
desc->status = status & ~IRQ_AUTODETECT;
desc->handler->shutdown(i);
}
spin_unlock_irq(&desc->lock);
}
up(&probe_sem);
return mask & val;
}
EXPORT_SYMBOL(probe_irq_mask);
/**
* probe_irq_off - end an interrupt autodetect
* @val: mask of potential interrupts (unused)
*
* Scans the unused interrupt lines and returns the line which
* appears to have triggered the interrupt. If no interrupt was
* found then zero is returned. If more than one interrupt is
* found then minus the first candidate is returned to indicate
* their is doubt.
*
* The interrupt probe logic state is returned to its previous
* value.
*
* BUGS: When used in a module (which arguably shouldn't happen)
* nothing prevents two IRQ probe callers from overlapping. The
* results of this are non-optimal.
*/
int probe_irq_off(unsigned long val)
{
int i, irq_found, nr_irqs;
nr_irqs = 0;
irq_found = 0;
for (i = 0; i < NR_IRQS; i++) {
irq_desc_t *desc = irq_descp(i);
unsigned int status;
spin_lock_irq(&desc->lock);
status = desc->status;
if (status & IRQ_AUTODETECT) {
if (!(status & IRQ_WAITING)) {
if (!nr_irqs)
irq_found = i;
nr_irqs++;
}
desc->status = status & ~IRQ_AUTODETECT;
desc->handler->shutdown(i);
}
spin_unlock_irq(&desc->lock);
}
up(&probe_sem);
if (nr_irqs > 1)
irq_found = -irq_found;
return irq_found;
}
EXPORT_SYMBOL(probe_irq_off);
int setup_irq(unsigned int irq, struct irqaction * new)
{
int shared = 0;
unsigned long flags;
struct irqaction *old, **p;
irq_desc_t *desc = irq_descp(irq);
if (desc->handler == &no_irq_type)
return -ENOSYS;
/*
* 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);
}
if (new->flags & SA_PERCPU_IRQ) {
desc->status |= IRQ_PER_CPU;
desc->handler = &irq_type_ia64_lsapic;
}
/*
* 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);
desc->handler->startup(irq);
}
spin_unlock_irqrestore(&desc->lock,flags);
register_irq_proc(irq);
return 0;
}
static struct proc_dir_entry * root_irq_dir;
static struct proc_dir_entry * irq_dir [NR_IRQS];
#ifdef CONFIG_SMP
static struct proc_dir_entry * smp_affinity_entry [NR_IRQS];
static cpumask_t irq_affinity [NR_IRQS] = { [0 ... NR_IRQS-1] = CPU_MASK_ALL };
static char irq_redir [NR_IRQS]; // = { [0 ... NR_IRQS-1] = 1 };
void set_irq_affinity_info (unsigned int irq, int hwid, int redir)
{
cpumask_t mask = CPU_MASK_NONE;
cpu_set(cpu_logical_id(hwid), mask);
if (irq < NR_IRQS) {
irq_affinity[irq] = mask;
irq_redir[irq] = (char) (redir & 0xff);
}
}
static int irq_affinity_read_proc (char *page, char **start, off_t off,
int count, int *eof, void *data)
{
int len = sprintf(page, "%s", irq_redir[(long)data] ? "r " : "");
len += cpumask_scnprintf(page+len, 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)
{
unsigned int irq = (unsigned long) data;
int full_count = count, err;
cpumask_t new_value, tmp;
# define R_PREFIX_LEN 16
char rbuf[R_PREFIX_LEN];
int rlen;
int prelen;
irq_desc_t *desc = irq_descp(irq);
unsigned long flags;
int redir = 0;
if (!desc->handler->set_affinity)
return -EIO;
/*
* If string being written starts with a prefix of 'r' or 'R'
* and some limited number of spaces, set IA64_IRQ_REDIRECTED.
* If more than (R_PREFIX_LEN - 2) spaces are passed, they won't
* all be trimmed as part of prelen, the untrimmed spaces will
* cause the hex parsing to fail, and this write() syscall will
* fail with EINVAL.
*/
if (!count)
return -EINVAL;
rlen = min(sizeof(rbuf)-1, count);
if (copy_from_user(rbuf, buffer, rlen))
return -EFAULT;
rbuf[rlen] = 0;
prelen = 0;
if (tolower(*rbuf) == 'r') {
prelen = strspn(rbuf, "Rr ");
redir++;
}
err = cpumask_parse(buffer+prelen, count-prelen, new_value);
if (err)
return err;
/*
* 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;
spin_lock_irqsave(&desc->lock, flags);
pending_irq_cpumask[irq] = new_value;
if (redir)
set_bit(irq, pending_irq_redir);
else
clear_bit(irq, pending_irq_redir);
spin_unlock_irqrestore(&desc->lock, flags);
return full_count;
}
void move_irq(int irq)
{
/* note - we hold desc->lock */
cpumask_t tmp;
irq_desc_t *desc = irq_descp(irq);
int redir = test_bit(irq, pending_irq_redir);
if (!cpus_empty(pending_irq_cpumask[irq])) {
cpus_and(tmp, pending_irq_cpumask[irq], cpu_online_map);
if (unlikely(!cpus_empty(tmp))) {
desc->handler->set_affinity(irq | (redir ? IA64_IRQ_REDIRECTED : 0),
pending_irq_cpumask[irq]);
}
cpus_clear(pending_irq_cpumask[irq]);
}
}
#endif /* CONFIG_SMP */
#ifdef CONFIG_HOTPLUG_CPU
unsigned int vectors_in_migration[NR_IRQS];
/*
* Since cpu_online_map is already updated, we just need to check for
* affinity that has zeros
*/
static void migrate_irqs(void)
{
cpumask_t mask;
irq_desc_t *desc;
int irq, new_cpu;
for (irq=0; irq < NR_IRQS; irq++) {
desc = irq_descp(irq);
/*
* No handling for now.
* TBD: Implement a disable function so we can now
* tell CPU not to respond to these local intr sources.
* such as ITV,CPEI,MCA etc.
*/
if (desc->status == IRQ_PER_CPU)
continue;
cpus_and(mask, irq_affinity[irq], cpu_online_map);
if (any_online_cpu(mask) == NR_CPUS) {
/*
* Save it for phase 2 processing
*/
vectors_in_migration[irq] = irq;
new_cpu = any_online_cpu(cpu_online_map);
mask = cpumask_of_cpu(new_cpu);
/*
* Al three are essential, currently WARN_ON.. maybe panic?
*/
if (desc->handler && desc->handler->disable &&
desc->handler->enable && desc->handler->set_affinity) {
desc->handler->disable(irq);
desc->handler->set_affinity(irq, mask);
desc->handler->enable(irq);
} else {
WARN_ON((!(desc->handler) || !(desc->handler->disable) ||
!(desc->handler->enable) ||
!(desc->handler->set_affinity)));
}
}
}
}
void fixup_irqs(void)
{
unsigned int irq;
extern void ia64_process_pending_intr(void);
ia64_set_itv(1<<16);
/*
* Phase 1: Locate irq's bound to this cpu and
* relocate them for cpu removal.
*/
migrate_irqs();
/*
* Phase 2: Perform interrupt processing for all entries reported in
* local APIC.
*/
ia64_process_pending_intr();
/*
* Phase 3: Now handle any interrupts not captured in local APIC.
* This is to account for cases that device interrupted during the time the
* rte was being disabled and re-programmed.
*/
for (irq=0; irq < NR_IRQS; irq++) {
if (vectors_in_migration[irq]) {
vectors_in_migration[irq]=0;
do_IRQ(irq, NULL);
}
}
/*
* Now let processor die. We do irq disable and max_xtp() to
* ensure there is no more interrupts routed to this processor.
* But the local timer interrupt can have 1 pending which we
* take care in timer_interrupt().
*/
max_xtp();
local_irq_disable();
}
#endif
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 *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;
return full_count;
}
#define MAX_NAMELEN 10
static void register_irq_proc (unsigned int irq)
{
char name [MAX_NAMELEN];
if (!root_irq_dir || (irq_descp(irq)->handler == &no_irq_type) || irq_dir[irq])
return;
memset(name, 0, MAX_NAMELEN);
sprintf(name, "%d", irq);
/* create /proc/irq/1234 */
irq_dir[irq] = proc_mkdir(name, root_irq_dir);
#ifdef CONFIG_SMP
{
struct proc_dir_entry *entry;
/* 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;
}
#endif
}
cpumask_t prof_cpu_mask = CPU_MASK_ALL;
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_descp(i)->handler == &no_irq_type)
continue;
register_irq_proc(i);
}
}
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