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kernel_samsung_sm7125/kernel/irq/manage.c

394 lines
9.5 KiB

/*
* linux/kernel/irq/manage.c
*
* Copyright (C) 1992, 1998-2004 Linus Torvalds, Ingo Molnar
*
* This file contains driver APIs to the irq subsystem.
*/
#include <linux/config.h>
#include <linux/irq.h>
#include <linux/module.h>
#include <linux/random.h>
#include <linux/interrupt.h>
#include "internals.h"
#ifdef CONFIG_SMP
cpumask_t irq_affinity[NR_IRQS] = { [0 ... NR_IRQS-1] = CPU_MASK_ALL };
[PATCH] x86/x86_64: deferred handling of writes to /proc/irqxx/smp_affinity When handling writes to /proc/irq, current code is re-programming rte entries directly. This is not recommended and could potentially cause chipset's to lockup, or cause missing interrupts. CONFIG_IRQ_BALANCE does this correctly, where it re-programs only when the interrupt is pending. The same needs to be done for /proc/irq handling as well. Otherwise user space irq balancers are really not doing the right thing. - Changed pending_irq_balance_cpumask to pending_irq_migrate_cpumask for lack of a generic name. - added move_irq out of IRQ_BALANCE, and added this same to X86_64 - Added new proc handler for write, so we can do deferred write at irq handling time. - Display of /proc/irq/XX/smp_affinity used to display CPU_MASKALL, instead it now shows only active cpu masks, or exactly what was set. - Provided a common move_irq implementation, instead of duplicating when using generic irq framework. Tested on i386/x86_64 and ia64 with CONFIG_PCI_MSI turned on and off. Tested UP builds as well. MSI testing: tbd: I have cards, need to look for a x-over cable, although I did test an earlier version of this patch. Will test in a couple days. Signed-off-by: Ashok Raj <ashok.raj@intel.com> Acked-by: Zwane Mwaikambo <zwane@holomorphy.com> Grudgingly-acked-by: Andi Kleen <ak@muc.de> Signed-off-by: Coywolf Qi Hunt <coywolf@lovecn.org> Signed-off-by: Ashok Raj <ashok.raj@intel.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
20 years ago
#if defined (CONFIG_GENERIC_PENDING_IRQ) || defined (CONFIG_IRQBALANCE)
cpumask_t __cacheline_aligned pending_irq_cpumask[NR_IRQS];
#endif
/**
* synchronize_irq - wait for pending IRQ handlers (on other CPUs)
* @irq: interrupt number to wait for
*
* 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 synchronize_irq(unsigned int irq)
{
struct irq_desc *desc = irq_desc + irq;
if (irq >= NR_IRQS)
return;
while (desc->status & IRQ_INPROGRESS)
cpu_relax();
}
EXPORT_SYMBOL(synchronize_irq);
#endif
/**
* 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.
*/
void disable_irq_nosync(unsigned int irq)
{
irq_desc_t *desc = irq_desc + irq;
unsigned long flags;
if (irq >= NR_IRQS)
return;
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_desc + irq;
if (irq >= NR_IRQS)
return;
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_desc + irq;
unsigned long flags;
if (irq >= NR_IRQS)
return;
spin_lock_irqsave(&desc->lock, flags);
switch (desc->depth) {
case 0:
WARN_ON(1);
break;
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--;
}
spin_unlock_irqrestore(&desc->lock, flags);
}
EXPORT_SYMBOL(enable_irq);
/*
* Internal function that tells the architecture code whether a
* particular irq has been exclusively allocated or is available
* for driver use.
*/
int can_request_irq(unsigned int irq, unsigned long irqflags)
{
struct irqaction *action;
if (irq >= NR_IRQS)
return 0;
action = irq_desc[irq].action;
if (action)
if (irqflags & action->flags & SA_SHIRQ)
action = NULL;
return !action;
}
/*
* Internal function to register an irqaction - typically used to
* allocate special interrupts that are part of the architecture.
*/
int setup_irq(unsigned int irq, struct irqaction * new)
{
struct irq_desc *desc = irq_desc + irq;
struct irqaction *old, **p;
unsigned long flags;
int shared = 0;
if (irq >= NR_IRQS)
return -EINVAL;
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);
}
/*
* 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))
goto mismatch;
#if defined(ARCH_HAS_IRQ_PER_CPU) && defined(SA_PERCPU_IRQ)
/* All handlers must agree on per-cpuness */
if ((old->flags & IRQ_PER_CPU) != (new->flags & IRQ_PER_CPU))
goto mismatch;
#endif
/* add new interrupt at end of irq queue */
do {
p = &old->next;
old = *p;
} while (old);
shared = 1;
}
*p = new;
#if defined(ARCH_HAS_IRQ_PER_CPU) && defined(SA_PERCPU_IRQ)
if (new->flags & SA_PERCPU_IRQ)
desc->status |= IRQ_PER_CPU;
#endif
if (!shared) {
desc->depth = 0;
desc->status &= ~(IRQ_DISABLED | IRQ_AUTODETECT |
IRQ_WAITING | IRQ_INPROGRESS);
if (desc->handler->startup)
desc->handler->startup(irq);
else
desc->handler->enable(irq);
}
spin_unlock_irqrestore(&desc->lock,flags);
new->irq = irq;
register_irq_proc(irq);
new->dir = NULL;
register_handler_proc(irq, new);
return 0;
mismatch:
spin_unlock_irqrestore(&desc->lock, flags);
printk(KERN_ERR "%s: irq handler mismatch\n", __FUNCTION__);
dump_stack();
return -EBUSY;
}
/**
* 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)
{
struct irq_desc *desc;
struct irqaction **p;
unsigned long flags;
WARN_ON(in_interrupt());
if (irq >= NR_IRQS)
return;
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;
[PATCH] uml: add and use generic hw_controller_type->release With Chris Wedgwood <cw@f00f.org> Currently UML must explicitly call the UML-specific free_irq_by_irq_and_dev() for each free_irq call it's done. This is needed because ->shutdown and/or ->disable are only called when the last "action" for that irq is removed. Instead, for UML shared IRQs (UML IRQs are very often, if not always, shared), for each dev_id some setup is done, which must be cleared on the release of that fd. For instance, for each open console a new instance (i.e. new dev_id) of the same IRQ is requested(). Exactly, a fd is stored in an array (pollfds), which is after read by a host thread and passed to poll(). Each event registered by poll() triggers an interrupt. So, for each free_irq() we must remove the corresponding host fd from the table, which we do via this -release() method. In this patch we add an appropriate hook for this, and remove all uses of it by pointing the hook to the said procedure; this is safe to do since the said procedure. Also some cosmetic improvements are included. This is heavily based on some work by Chris Wedgwood, which however didn't get the patch merged for something I'd call a "misunderstanding" (the need for this patch wasn't cleanly explained, thus adding the generic hook was felt as undesirable). Signed-off-by: Paolo 'Blaisorblade' Giarrusso <blaisorblade@yahoo.it> CC: Ingo Molnar <mingo@redhat.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
20 years ago
/* Currently used only by UML, might disappear one day.*/
#ifdef CONFIG_IRQ_RELEASE_METHOD
[PATCH] uml: add and use generic hw_controller_type->release With Chris Wedgwood <cw@f00f.org> Currently UML must explicitly call the UML-specific free_irq_by_irq_and_dev() for each free_irq call it's done. This is needed because ->shutdown and/or ->disable are only called when the last "action" for that irq is removed. Instead, for UML shared IRQs (UML IRQs are very often, if not always, shared), for each dev_id some setup is done, which must be cleared on the release of that fd. For instance, for each open console a new instance (i.e. new dev_id) of the same IRQ is requested(). Exactly, a fd is stored in an array (pollfds), which is after read by a host thread and passed to poll(). Each event registered by poll() triggers an interrupt. So, for each free_irq() we must remove the corresponding host fd from the table, which we do via this -release() method. In this patch we add an appropriate hook for this, and remove all uses of it by pointing the hook to the said procedure; this is safe to do since the said procedure. Also some cosmetic improvements are included. This is heavily based on some work by Chris Wedgwood, which however didn't get the patch merged for something I'd call a "misunderstanding" (the need for this patch wasn't cleanly explained, thus adding the generic hook was felt as undesirable). Signed-off-by: Paolo 'Blaisorblade' Giarrusso <blaisorblade@yahoo.it> CC: Ingo Molnar <mingo@redhat.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
20 years ago
if (desc->handler->release)
desc->handler->release(irq, dev_id);
#endif
[PATCH] uml: add and use generic hw_controller_type->release With Chris Wedgwood <cw@f00f.org> Currently UML must explicitly call the UML-specific free_irq_by_irq_and_dev() for each free_irq call it's done. This is needed because ->shutdown and/or ->disable are only called when the last "action" for that irq is removed. Instead, for UML shared IRQs (UML IRQs are very often, if not always, shared), for each dev_id some setup is done, which must be cleared on the release of that fd. For instance, for each open console a new instance (i.e. new dev_id) of the same IRQ is requested(). Exactly, a fd is stored in an array (pollfds), which is after read by a host thread and passed to poll(). Each event registered by poll() triggers an interrupt. So, for each free_irq() we must remove the corresponding host fd from the table, which we do via this -release() method. In this patch we add an appropriate hook for this, and remove all uses of it by pointing the hook to the said procedure; this is safe to do since the said procedure. Also some cosmetic improvements are included. This is heavily based on some work by Chris Wedgwood, which however didn't get the patch merged for something I'd call a "misunderstanding" (the need for this patch wasn't cleanly explained, thus adding the generic hook was felt as undesirable). Signed-off-by: Paolo 'Blaisorblade' Giarrusso <blaisorblade@yahoo.it> CC: Ingo Molnar <mingo@redhat.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
20 years ago
if (!desc->action) {
desc->status |= IRQ_DISABLED;
if (desc->handler->shutdown)
desc->handler->shutdown(irq);
else
desc->handler->disable(irq);
}
spin_unlock_irqrestore(&desc->lock,flags);
unregister_handler_proc(irq, action);
/* 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);
/**
* 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)
{
struct irqaction * action;
int retval;
/*
* Sanity-check: shared interrupts must 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) && !dev_id)
return -EINVAL;
if (irq >= NR_IRQS)
return -EINVAL;
if (!handler)
return -EINVAL;
action = 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;
select_smp_affinity(irq);
retval = setup_irq(irq, action);
if (retval)
kfree(action);
return retval;
}
EXPORT_SYMBOL(request_irq);