path: root/include/linux/irqdesc.h
diff options
authorMarc Zyngier <>2011-09-23 17:03:06 +0100
committerThomas Gleixner <>2011-10-03 15:35:26 +0200
commit31d9d9b6d83030f748d013e61502fa5477e2ac0e (patch)
tree503670b94d594c09daa83c047b426e7b5328aa76 /include/linux/irqdesc.h
parent60f96b41f71d2a13d1c0a457b8b77958f77142d1 (diff)
genirq: Add support for per-cpu dev_id interrupts
The ARM GIC interrupt controller offers per CPU interrupts (PPIs), which are usually used to connect local timers to each core. Each CPU has its own private interface to the GIC, and only sees the PPIs that are directly connect to it. While these timers are separate devices and have a separate interrupt line to a core, they all use the same IRQ number. For these devices, request_irq() is not the right API as it assumes that an IRQ number is visible by a number of CPUs (through the affinity setting), but makes it very awkward to express that an IRQ number can be handled by all CPUs, and yet be a different interrupt line on each CPU, requiring a different dev_id cookie to be passed back to the handler. The *_percpu_irq() functions is designed to overcome these limitations, by providing a per-cpu dev_id vector: int request_percpu_irq(unsigned int irq, irq_handler_t handler, const char *devname, void __percpu *percpu_dev_id); void free_percpu_irq(unsigned int, void __percpu *); int setup_percpu_irq(unsigned int irq, struct irqaction *new); void remove_percpu_irq(unsigned int irq, struct irqaction *act); void enable_percpu_irq(unsigned int irq); void disable_percpu_irq(unsigned int irq); The API has a number of limitations: - no interrupt sharing - no threading - common handler across all the CPUs Once the interrupt is requested using setup_percpu_irq() or request_percpu_irq(), it must be enabled by each core that wishes its local interrupt to be delivered. Based on an initial patch by Thomas Gleixner. Signed-off-by: Marc Zyngier <> Cc: Link: Signed-off-by: Thomas Gleixner <>
Diffstat (limited to 'include/linux/irqdesc.h')
1 files changed, 1 insertions, 0 deletions
diff --git a/include/linux/irqdesc.h b/include/linux/irqdesc.h
index 150134ac709a..6b69c2c9dff1 100644
--- a/include/linux/irqdesc.h
+++ b/include/linux/irqdesc.h
@@ -53,6 +53,7 @@ struct irq_desc {
unsigned long last_unhandled; /* Aging timer for unhandled count */
unsigned int irqs_unhandled;
raw_spinlock_t lock;
+ struct cpumask *percpu_enabled;
const struct cpumask *affinity_hint;
struct irq_affinity_notify *affinity_notify;