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authorKeith Busch <keith.busch@intel.com>2016-06-17 16:00:20 -0600
committerThomas Gleixner <tglx@linutronix.de>2016-06-18 10:00:55 +0200
commitedd14cfebc4404698544d407ecf8eda6e19aa19e (patch)
treec8e821937f59152ba61129fdcfda0d52416302f8 /kernel/irq/handle.c
parent21c57fd135894f69ba2b8acc715ca81e90eeba15 (diff)
downloadlinux-stericsson-edd14cfebc4404698544d407ecf8eda6e19aa19e.tar.gz
genirq: Add untracked irq handler
This adds a software irq handler for controllers that multiplex interrupts from multiple devices, but don't know which device generated the interrupt. For these devices, the irq handler that demuxes must check every action for every software irq using the same h/w irq in order to find out which device generated the interrupt. This will inevitably trigger spurious interrupt detection if we are noting the irq. The new irq handler does not track the handling for spurious interrupt detection. An irq that uses this also won't get stats tracked since it didn't generate the interrupt, nor added to randomness since they are not random. Signed-off-by: Keith Busch <keith.busch@intel.com> Cc: Bjorn Helgaas <bhelgaas@google.com> Cc: linux-pci@vger.kernel.org Cc: Jon Derrick <jonathan.derrick@intel.com> Link: http://lkml.kernel.org/r/1466200821-29159-1-git-send-email-keith.busch@intel.com Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Diffstat (limited to 'kernel/irq/handle.c')
-rw-r--r--kernel/irq/handle.c18
1 files changed, 14 insertions, 4 deletions
diff --git a/kernel/irq/handle.c b/kernel/irq/handle.c
index a15b5485b446..d3f24905852c 100644
--- a/kernel/irq/handle.c
+++ b/kernel/irq/handle.c
@@ -132,10 +132,10 @@ void __irq_wake_thread(struct irq_desc *desc, struct irqaction *action)
wake_up_process(action->thread);
}
-irqreturn_t handle_irq_event_percpu(struct irq_desc *desc)
+irqreturn_t __handle_irq_event_percpu(struct irq_desc *desc, unsigned int *flags)
{
irqreturn_t retval = IRQ_NONE;
- unsigned int flags = 0, irq = desc->irq_data.irq;
+ unsigned int irq = desc->irq_data.irq;
struct irqaction *action;
for_each_action_of_desc(desc, action) {
@@ -164,7 +164,7 @@ irqreturn_t handle_irq_event_percpu(struct irq_desc *desc)
/* Fall through to add to randomness */
case IRQ_HANDLED:
- flags |= action->flags;
+ *flags |= action->flags;
break;
default:
@@ -174,7 +174,17 @@ irqreturn_t handle_irq_event_percpu(struct irq_desc *desc)
retval |= res;
}
- add_interrupt_randomness(irq, flags);
+ return retval;
+}
+
+irqreturn_t handle_irq_event_percpu(struct irq_desc *desc)
+{
+ irqreturn_t retval;
+ unsigned int flags = 0;
+
+ retval = __handle_irq_event_percpu(desc, &flags);
+
+ add_interrupt_randomness(desc->irq_data.irq, flags);
if (!noirqdebug)
note_interrupt(desc, retval);