From 46f4f8f665080900e865392f4b3593be463bf0d8 Mon Sep 17 00:00:00 2001 From: Ralf Baechle Date: Fri, 8 Feb 2008 04:22:01 -0800 Subject: [PATCH] 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 Acked-and-tested-by: Rob Landley Cc: Alan Cox Cc: Ingo Molnar Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- include/linux/irq.h | 3 +++ kernel/irq/chip.c | 36 ++++++++++++++++++++++++++++++++++++ 2 files changed, 39 insertions(+) diff --git a/include/linux/irq.h b/include/linux/irq.h index a19b381d4112..bfd9efb5cb49 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 10e006643c8c..cc54c6276356 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); +} -- 2.30.2