From 31d9d9b6d83030f748d013e61502fa5477e2ac0e Mon Sep 17 00:00:00 2001 From: Marc Zyngier Date: Fri, 23 Sep 2011 17:03:06 +0100 Subject: 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: linux-arm-kernel@lists.infradead.org Link: http://lkml.kernel.org/r/1316793788-14500-2-git-send-email-marc.zyngier@arm.com Signed-off-by: Thomas Gleixner --- include/linux/interrupt.h | 38 +++++++++++++++++++++++++++----------- 1 file changed, 27 insertions(+), 11 deletions(-) (limited to 'include/linux/interrupt.h') diff --git a/include/linux/interrupt.h b/include/linux/interrupt.h index a103732b758..1cdfd09c8ab 100644 --- a/include/linux/interrupt.h +++ b/include/linux/interrupt.h @@ -95,6 +95,7 @@ typedef irqreturn_t (*irq_handler_t)(int, void *); * @flags: flags (see IRQF_* above) * @name: name of the device * @dev_id: cookie to identify the device + * @percpu_dev_id: cookie to identify the device * @next: pointer to the next irqaction for shared interrupts * @irq: interrupt number * @dir: pointer to the proc/irq/NN/name entry @@ -104,17 +105,18 @@ typedef irqreturn_t (*irq_handler_t)(int, void *); * @thread_mask: bitmask for keeping track of @thread activity */ struct irqaction { - irq_handler_t handler; - unsigned long flags; - void *dev_id; - struct irqaction *next; - int irq; - irq_handler_t thread_fn; - struct task_struct *thread; - unsigned long thread_flags; - unsigned long thread_mask; - const char *name; - struct proc_dir_entry *dir; + irq_handler_t handler; + unsigned long flags; + void *dev_id; + void __percpu *percpu_dev_id; + struct irqaction *next; + int irq; + irq_handler_t thread_fn; + struct task_struct *thread; + unsigned long thread_flags; + unsigned long thread_mask; + const char *name; + struct proc_dir_entry *dir; } ____cacheline_internodealigned_in_smp; extern irqreturn_t no_action(int cpl, void *dev_id); @@ -136,6 +138,10 @@ extern int __must_check request_any_context_irq(unsigned int irq, irq_handler_t handler, unsigned long flags, const char *name, void *dev_id); +extern int __must_check +request_percpu_irq(unsigned int irq, irq_handler_t handler, + const char *devname, void __percpu *percpu_dev_id); + extern void exit_irq_thread(void); #else @@ -164,10 +170,18 @@ request_any_context_irq(unsigned int irq, irq_handler_t handler, return request_irq(irq, handler, flags, name, dev_id); } +static inline int __must_check +request_percpu_irq(unsigned int irq, irq_handler_t handler, + const char *devname, void __percpu *percpu_dev_id) +{ + return request_irq(irq, handler, 0, devname, percpu_dev_id); +} + static inline void exit_irq_thread(void) { } #endif extern void free_irq(unsigned int, void *); +extern void free_percpu_irq(unsigned int, void __percpu *); struct device; @@ -207,7 +221,9 @@ extern void devm_free_irq(struct device *dev, unsigned int irq, void *dev_id); extern void disable_irq_nosync(unsigned int irq); extern void disable_irq(unsigned int irq); +extern void disable_percpu_irq(unsigned int irq); extern void enable_irq(unsigned int irq); +extern void enable_percpu_irq(unsigned int irq); /* The following three functions are for the core kernel use only. */ #ifdef CONFIG_GENERIC_HARDIRQS -- cgit v1.2.3-70-g09d2