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authorRalf Baechle <ralf@linux-mips.org>2008-02-08 04:22:01 -0800
committerLinus Torvalds <torvalds@woody.linux-foundation.org>2008-02-08 09:22:42 -0800
commit46f4f8f665080900e865392f4b3593be463bf0d8 (patch)
treed4d1cb04b461b4ddd841396647d911fdc08819ef
parent922f9cfa79b52c85b6002d96cb0eefd13437c58c (diff)
IRQ_NOPROBE helper functions
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>
-rw-r--r--include/linux/irq.h3
-rw-r--r--kernel/irq/chip.c36
2 files changed, 39 insertions, 0 deletions
diff --git a/include/linux/irq.h b/include/linux/irq.h
index a19b381d411..bfd9efb5cb4 100644
--- a/include/linux/irq.h
+++ b/include/linux/irq.h
@@ -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);
diff --git a/kernel/irq/chip.c b/kernel/irq/chip.c
index 10e006643c8..cc54c627635 100644
--- a/kernel/irq/chip.c
+++ b/kernel/irq/chip.c
@@ -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);
+}