Messages in this thread Patch in this message | | | Date | Fri, 21 Mar 2008 15:43:05 -0700 | From | Chris Wright <> | Subject | [patch 15/76] IRQ_NOPROBE helper functions |
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-stable review patch. If anyone has any objections, please let us know. ---------------------
From: Ralf Baechle <ralf@linux-mips.org>
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> Signed-off-by: Chris Wright <chrisw@sous-sol.org> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de> --- include/linux/irq.h | 3 +++ kernel/irq/chip.c | 36 ++++++++++++++++++++++++++++++++++++ 2 files changed, 39 insertions(+)
--- linux-2.6.24.3.orig/include/linux/irq.h +++ linux-2.6.24.3/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); --- linux-2.6.24.3.orig/kernel/irq/chip.c +++ linux-2.6.24.3/kernel/irq/chip.c @@ -607,3 +607,39 @@ set_irq_chip_and_handler_name(unsigned i 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); +} --
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