linux/kernel/irq/autoprobe.c

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/*
* linux/kernel/irq/autoprobe.c
*
* Copyright (C) 1992, 1998-2004 Linus Torvalds, Ingo Molnar
*
* This file contains the interrupt probing code and driver APIs.
*/
#include <linux/irq.h>
#include <linux/module.h>
#include <linux/interrupt.h>
#include <linux/delay.h>
#include "internals.h"
/*
* Autodetection 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 DEFINE_MUTEX(probing_active);
/**
* 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)
{
struct irq_desc *desc;
unsigned long mask = 0;
unsigned int status;
int i;
mutex_lock(&probing_active);
/*
* something may have generated an irq long ago and we want to
* flush such a longstanding irq before considering it as spurious.
*/
for_each_irq_desc_reverse(i, desc) {
spin_lock_irq(&desc->lock);
if (!desc->action && !(desc->status & IRQ_NOPROBE)) {
/*
* An old-style architecture might still have
* the handle_bad_irq handler there:
*/
compat_irq_chip_set_default_handler(desc);
/*
* Some chips need to know about probing in
* progress:
*/
if (desc->chip->set_type)
desc->chip->set_type(i, IRQ_TYPE_PROBE);
desc->chip->startup(i);
}
spin_unlock_irq(&desc->lock);
}
/* Wait for longstanding interrupts to trigger. */
msleep(20);
/*
* 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_each_irq_desc_reverse(i, desc) {
spin_lock_irq(&desc->lock);
if (!desc->action && !(desc->status & IRQ_NOPROBE)) {
desc->status |= IRQ_AUTODETECT | IRQ_WAITING;
[PATCH] genirq: rename desc->handler to desc->chip This patch-queue improves the generic IRQ layer to be truly generic, by adding various abstractions and features to it, without impacting existing functionality. While the queue can be best described as "fix and improve everything in the generic IRQ layer that we could think of", and thus it consists of many smaller features and lots of cleanups, the one feature that stands out most is the new 'irq chip' abstraction. The irq-chip abstraction is about describing and coding and IRQ controller driver by mapping its raw hardware capabilities [and quirks, if needed] in a straightforward way, without having to think about "IRQ flow" (level/edge/etc.) type of details. This stands in contrast with the current 'irq-type' model of genirq architectures, which 'mixes' raw hardware capabilities with 'flow' details. The patchset supports both types of irq controller designs at once, and converts i386 and x86_64 to the new irq-chip design. As a bonus side-effect of the irq-chip approach, chained interrupt controllers (master/slave PIC constructs, etc.) are now supported by design as well. The end result of this patchset intends to be simpler architecture-level code and more consolidation between architectures. We reused many bits of code and many concepts from Russell King's ARM IRQ layer, the merging of which was one of the motivations for this patchset. This patch: rename desc->handler to desc->chip. Originally i did not want to do this, because it's a big patch. But having both "desc->handler", "desc->handle_irq" and "action->handler" caused a large degree of confusion and made the code appear alot less clean than it truly is. I have also attempted a dual approach as well by introducing a desc->chip alias - but that just wasnt robust enough and broke frequently. So lets get over with this quickly. The conversion was done automatically via scripts and converts all the code in the kernel. This renaming patch is the first one amongst the patches, so that the remaining patches can stay flexible and can be merged and split up without having some big monolithic patch act as a merge barrier. [akpm@osdl.org: build fix] [akpm@osdl.org: another build fix] Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-06-29 09:24:36 +00:00
if (desc->chip->startup(i))
desc->status |= IRQ_PENDING;
}
spin_unlock_irq(&desc->lock);
}
/*
* Wait for spurious interrupts to trigger
*/
msleep(100);
/*
* Now filter out any obviously spurious interrupts
*/
for_each_irq_desc(i, desc) {
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;
[PATCH] genirq: rename desc->handler to desc->chip This patch-queue improves the generic IRQ layer to be truly generic, by adding various abstractions and features to it, without impacting existing functionality. While the queue can be best described as "fix and improve everything in the generic IRQ layer that we could think of", and thus it consists of many smaller features and lots of cleanups, the one feature that stands out most is the new 'irq chip' abstraction. The irq-chip abstraction is about describing and coding and IRQ controller driver by mapping its raw hardware capabilities [and quirks, if needed] in a straightforward way, without having to think about "IRQ flow" (level/edge/etc.) type of details. This stands in contrast with the current 'irq-type' model of genirq architectures, which 'mixes' raw hardware capabilities with 'flow' details. The patchset supports both types of irq controller designs at once, and converts i386 and x86_64 to the new irq-chip design. As a bonus side-effect of the irq-chip approach, chained interrupt controllers (master/slave PIC constructs, etc.) are now supported by design as well. The end result of this patchset intends to be simpler architecture-level code and more consolidation between architectures. We reused many bits of code and many concepts from Russell King's ARM IRQ layer, the merging of which was one of the motivations for this patchset. This patch: rename desc->handler to desc->chip. Originally i did not want to do this, because it's a big patch. But having both "desc->handler", "desc->handle_irq" and "action->handler" caused a large degree of confusion and made the code appear alot less clean than it truly is. I have also attempted a dual approach as well by introducing a desc->chip alias - but that just wasnt robust enough and broke frequently. So lets get over with this quickly. The conversion was done automatically via scripts and converts all the code in the kernel. This renaming patch is the first one amongst the patches, so that the remaining patches can stay flexible and can be merged and split up without having some big monolithic patch act as a merge barrier. [akpm@osdl.org: build fix] [akpm@osdl.org: another build fix] Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-06-29 09:24:36 +00:00
desc->chip->shutdown(i);
} else
if (i < 32)
mask |= 1 << i;
}
spin_unlock_irq(&desc->lock);
}
return mask;
}
EXPORT_SYMBOL(probe_irq_on);
/**
* probe_irq_mask - scan a bitmap of interrupt lines
* @val: mask of interrupts to consider
*
* Scan the interrupt lines and return a bitmap of active
* autodetect 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 autodetect irq numbers - just so that we reset
* them all to a known state.
*/
unsigned int probe_irq_mask(unsigned long val)
{
unsigned int status, mask = 0;
struct irq_desc *desc;
int i;
for_each_irq_desc(i, desc) {
spin_lock_irq(&desc->lock);
status = desc->status;
if (status & IRQ_AUTODETECT) {
if (i < 16 && !(status & IRQ_WAITING))
mask |= 1 << i;
desc->status = status & ~IRQ_AUTODETECT;
[PATCH] genirq: rename desc->handler to desc->chip This patch-queue improves the generic IRQ layer to be truly generic, by adding various abstractions and features to it, without impacting existing functionality. While the queue can be best described as "fix and improve everything in the generic IRQ layer that we could think of", and thus it consists of many smaller features and lots of cleanups, the one feature that stands out most is the new 'irq chip' abstraction. The irq-chip abstraction is about describing and coding and IRQ controller driver by mapping its raw hardware capabilities [and quirks, if needed] in a straightforward way, without having to think about "IRQ flow" (level/edge/etc.) type of details. This stands in contrast with the current 'irq-type' model of genirq architectures, which 'mixes' raw hardware capabilities with 'flow' details. The patchset supports both types of irq controller designs at once, and converts i386 and x86_64 to the new irq-chip design. As a bonus side-effect of the irq-chip approach, chained interrupt controllers (master/slave PIC constructs, etc.) are now supported by design as well. The end result of this patchset intends to be simpler architecture-level code and more consolidation between architectures. We reused many bits of code and many concepts from Russell King's ARM IRQ layer, the merging of which was one of the motivations for this patchset. This patch: rename desc->handler to desc->chip. Originally i did not want to do this, because it's a big patch. But having both "desc->handler", "desc->handle_irq" and "action->handler" caused a large degree of confusion and made the code appear alot less clean than it truly is. I have also attempted a dual approach as well by introducing a desc->chip alias - but that just wasnt robust enough and broke frequently. So lets get over with this quickly. The conversion was done automatically via scripts and converts all the code in the kernel. This renaming patch is the first one amongst the patches, so that the remaining patches can stay flexible and can be merged and split up without having some big monolithic patch act as a merge barrier. [akpm@osdl.org: build fix] [akpm@osdl.org: another build fix] Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-06-29 09:24:36 +00:00
desc->chip->shutdown(i);
}
spin_unlock_irq(&desc->lock);
}
mutex_unlock(&probing_active);
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 = 0, nr_of_irqs = 0;
struct irq_desc *desc;
unsigned int status;
for_each_irq_desc(i, desc) {
spin_lock_irq(&desc->lock);
status = desc->status;
if (status & IRQ_AUTODETECT) {
if (!(status & IRQ_WAITING)) {
if (!nr_of_irqs)
irq_found = i;
nr_of_irqs++;
}
desc->status = status & ~IRQ_AUTODETECT;
[PATCH] genirq: rename desc->handler to desc->chip This patch-queue improves the generic IRQ layer to be truly generic, by adding various abstractions and features to it, without impacting existing functionality. While the queue can be best described as "fix and improve everything in the generic IRQ layer that we could think of", and thus it consists of many smaller features and lots of cleanups, the one feature that stands out most is the new 'irq chip' abstraction. The irq-chip abstraction is about describing and coding and IRQ controller driver by mapping its raw hardware capabilities [and quirks, if needed] in a straightforward way, without having to think about "IRQ flow" (level/edge/etc.) type of details. This stands in contrast with the current 'irq-type' model of genirq architectures, which 'mixes' raw hardware capabilities with 'flow' details. The patchset supports both types of irq controller designs at once, and converts i386 and x86_64 to the new irq-chip design. As a bonus side-effect of the irq-chip approach, chained interrupt controllers (master/slave PIC constructs, etc.) are now supported by design as well. The end result of this patchset intends to be simpler architecture-level code and more consolidation between architectures. We reused many bits of code and many concepts from Russell King's ARM IRQ layer, the merging of which was one of the motivations for this patchset. This patch: rename desc->handler to desc->chip. Originally i did not want to do this, because it's a big patch. But having both "desc->handler", "desc->handle_irq" and "action->handler" caused a large degree of confusion and made the code appear alot less clean than it truly is. I have also attempted a dual approach as well by introducing a desc->chip alias - but that just wasnt robust enough and broke frequently. So lets get over with this quickly. The conversion was done automatically via scripts and converts all the code in the kernel. This renaming patch is the first one amongst the patches, so that the remaining patches can stay flexible and can be merged and split up without having some big monolithic patch act as a merge barrier. [akpm@osdl.org: build fix] [akpm@osdl.org: another build fix] Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-06-29 09:24:36 +00:00
desc->chip->shutdown(i);
}
spin_unlock_irq(&desc->lock);
}
mutex_unlock(&probing_active);
if (nr_of_irqs > 1)
irq_found = -irq_found;
return irq_found;
}
EXPORT_SYMBOL(probe_irq_off);