On Mon, 21 Mar 2011, David Daney wrote:
On 03/19/2011 01:51 PM, Thomas Gleixner wrote:On Fri, 18 Mar 2011, David Daney wrote:--- a/include/linux/irqdesc.h
@@ -178,6 +178,12 @@ static inline int irq_has_action(unsigned int irq)
return desc->action != NULL;
+/* Test to see if the irq is currently enabled */
+static inline int irq_desc_is_enabled(struct irq_desc *desc)
+ return desc->depth == 0;
That want's to go into kernel/irq/internal.h
I think I need to use this in my irq_chip.irq_unmask method.
handle level irq does:
if (!(desc->istate& (IRQS_DISABLED | IRQS_ONESHOT)))
So it does not call unmask.
I need to know in my .unmask method if the interrupt has been disabled. If it
has, I will not re-enable (unmask)it.
It wont be called :)
static inline int irq_balancing_disabled(unsigned int irq)
diff --git a/kernel/irq/chip.c b/kernel/irq/chip.c
index c9c0601..40736f7 100644
@@ -689,3 +689,38 @@ void irq_modify_status(unsigned int irq, unsigned
long clr, unsigned long set)
+void irq_cpu_online(unsigned int irq)
Odd function name. It does not reflect that this is for per cpu
interrupts. So something like irq_xxx_per_cpu_irq(irq)
might be a bit more descriptive.
I am using it for per cpu interrupts, but I didn't want to impose that policy
I can't imagine any other purpose for that.
Though one question remains: should we just iterate over the irq space
and call the online/offline callbacks when available instead of having
the arch code do the iteration.
That would be good I think, especially for sparse irqs.
In the case of the CPU going offline, the .irq_cpu_offline() may need to
adjust the affinity so that the irq no longer has affinity for the off-lined
This is something needed even for non-per-cpu interrupts. Also I would need a
way to call irq_set_affinity() while holding the desc->lock.
Hmm. The offline fixup_irq() code is arch specific and usually calls
desc->irq_data.chip->irq_set_affinity under desc->lock. I have not yet
found an arch independent way to do that. Any ideas welcome.