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IRQ_NOPROBE helper functions

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Probing non-ISA interrupts using the handle_percpu_irq as their handle_irq
method may crash the system because handle_percpu_irq does not check
IRQ_WAITING.  This for example hits the MIPS Qemu configuration.

This patch provides two helper functions set_irq_noprobe and set_irq_probe to
set rsp.  clear the IRQ_NOPROBE flag.  The only current caller is MIPS code
but this really belongs into generic code.

As an aside, interrupt probing these days has become a mostly obsolete if not
dangerous art.  I think Linux interrupts should be changed to default to
non-probing but that's subject of this patch.

Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
Acked-and-tested-by: Rob Landley <rob@landley.net>
Cc: Alan Cox <alan@lxorguk.ukuu.org.uk>
Cc: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This commit is contained in:
Ralf Baechle 2008-02-08 04:22:01 -08:00 committed by Linus Torvalds
parent 922f9cfa79
commit 46f4f8f665
2 changed files with 39 additions and 0 deletions
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3
include/linux/irq.h
View file

@ -367,6 +367,9 @@ set_irq_chained_handler(unsigned int irq,
__set_irq_handler(irq, handle, 1, NULL);
}
extern void set_irq_noprobe(unsigned int irq);
extern void set_irq_probe(unsigned int irq);
/* Handle dynamic irq creation and destruction */
extern int create_irq(void);
extern void destroy_irq(unsigned int irq);

36
kernel/irq/chip.c
View file

@ -589,3 +589,39 @@ set_irq_chip_and_handler_name(unsigned int irq, struct irq_chip *chip,
set_irq_chip(irq, chip);
__set_irq_handler(irq, handle, 0, name);
}
void __init set_irq_noprobe(unsigned int irq)
{
struct irq_desc *desc;
unsigned long flags;
if (irq >= NR_IRQS) {
printk(KERN_ERR "Trying to mark IRQ%d non-probeable\n", irq);
return;
}
desc = irq_desc + irq;
spin_lock_irqsave(&desc->lock, flags);
desc->status |= IRQ_NOPROBE;
spin_unlock_irqrestore(&desc->lock, flags);
}
void __init set_irq_probe(unsigned int irq)
{
struct irq_desc *desc;
unsigned long flags;
if (irq >= NR_IRQS) {
printk(KERN_ERR "Trying to mark IRQ%d probeable\n", irq);
return;
}
desc = irq_desc + irq;
spin_lock_irqsave(&desc->lock, flags);
desc->status &= ~IRQ_NOPROBE;
spin_unlock_irqrestore(&desc->lock, flags);
}