From ae731f8d0785ccd3380f511bae888933b6562e45 Mon Sep 17 00:00:00 2001 From: Marc Zyngier Date: Mon, 15 Mar 2010 22:56:33 +0000 Subject: genirq: Introduce request_any_context_irq() Now that we enjoy threaded interrupts, we're starting to see irq_chip implementations (wm831x, pca953x) that make use of threaded interrupts for the controller, and nested interrupts for the client interrupt. It all works very well, with one drawback: Drivers requesting an IRQ must now know whether the handler will run in a thread context or not, and call request_threaded_irq() or request_irq() accordingly. The problem is that the requesting driver sometimes doesn't know about the nature of the interrupt, specially when the interrupt controller is a discrete chip (typically a GPIO expander connected over I2C) that can be connected to a wide variety of otherwise perfectly supported hardware. This patch introduces the request_any_context_irq() function that mostly mimics the usual request_irq(), except that it checks whether the irq level is configured as nested or not, and calls the right backend. On success, it also returns either IRQC_IS_HARDIRQ or IRQC_IS_NESTED. [ tglx: Made return value an enum, simplified code and made the export of request_any_context_irq GPL ] Signed-off-by: Marc Zyngier Cc: LKML-Reference: <927ea285bd0c68934ddae1a47e44a9ba@localhost> Signed-off-by: Thomas Gleixner --- include/linux/interrupt.h | 23 +++++++++++++++++++++++ 1 file changed, 23 insertions(+) (limited to 'include') diff --git a/include/linux/interrupt.h b/include/linux/interrupt.h index 75f3f00ac1e5..d7e7a7660c6c 100644 --- a/include/linux/interrupt.h +++ b/include/linux/interrupt.h @@ -77,6 +77,18 @@ enum { IRQTF_AFFINITY, }; +/** + * These values can be returned by request_any_context_irq() and + * describe the context the interrupt will be run in. + * + * IRQC_IS_HARDIRQ - interrupt runs in hardirq context + * IRQC_IS_NESTED - interrupt runs in a nested threaded context + */ +enum { + IRQC_IS_HARDIRQ = 0, + IRQC_IS_NESTED, +}; + typedef irqreturn_t (*irq_handler_t)(int, void *); /** @@ -120,6 +132,10 @@ request_irq(unsigned int irq, irq_handler_t handler, unsigned long flags, return request_threaded_irq(irq, handler, NULL, flags, name, dev); } +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 void exit_irq_thread(void); #else @@ -141,6 +157,13 @@ request_threaded_irq(unsigned int irq, irq_handler_t handler, return request_irq(irq, handler, flags, name, dev); } +static inline int __must_check +request_any_context_irq(unsigned int irq, irq_handler_t handler, + unsigned long flags, const char *name, void *dev_id) +{ + return request_irq(irq, handler, flags, name, dev_id); +} + static inline void exit_irq_thread(void) { } #endif -- cgit v1.2.3 From 6932bf37bed45ce8ed531928b1b0f98162fe6df6 Mon Sep 17 00:00:00 2001 From: Thomas Gleixner Date: Fri, 26 Mar 2010 00:06:55 +0000 Subject: genirq: Remove IRQF_DISABLED from core code Remove all code which is related to IRQF_DISABLED from the core kernel code. IRQF_DISABLED still exists as a flag, but becomes a NOOP and will be removed after a grace period. That way we can easily revert to the previous behaviour by just restoring the core code. Signed-off-by: Thomas Gleixner Cc: Peter Zijlstra Cc: Alan Cox Cc: Andi Kleen Cc: David Miller Cc: Greg Kroah-Hartman Cc: Arnaldo Carvalho de Melo Cc: Linus Torvalds LKML-Reference: <20100326000405.991244690@linutronix.de> --- include/linux/interrupt.h | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) (limited to 'include') diff --git a/include/linux/interrupt.h b/include/linux/interrupt.h index d7e7a7660c6c..e6d2f4441fda 100644 --- a/include/linux/interrupt.h +++ b/include/linux/interrupt.h @@ -39,7 +39,8 @@ * These flags used only by the kernel as part of the * irq handling routines. * - * IRQF_DISABLED - keep irqs disabled when calling the action handler + * IRQF_DISABLED - keep irqs disabled when calling the action handler. + * DEPRECATED. This flag is a NOOP and scheduled to be removed * IRQF_SAMPLE_RANDOM - irq is used to feed the random generator * IRQF_SHARED - allow sharing the irq among several devices * IRQF_PROBE_SHARED - set by callers when they expect sharing mismatches to occur -- cgit v1.2.3 From e7a297b0d7d6049bd4e423ac1e17da31e4c401b8 Mon Sep 17 00:00:00 2001 From: Peter P Waskiewicz Jr Date: Fri, 30 Apr 2010 14:44:50 -0700 Subject: genirq: Add CPU mask affinity hint This patch adds a cpumask affinity hint to the irq_desc structure, along with a registration function and a read-only proc entry for each interrupt. This affinity_hint handle for each interrupt can be used by underlying drivers that need a better mechanism to control interrupt affinity. The underlying driver can register a cpumask for the interrupt, which will allow the driver to provide the CPU mask for the interrupt to anything that requests it. The intent is to extend the userspace daemon, irqbalance, to help hint to it a preferred CPU mask to balance the interrupt into. [ tglx: Fixed compile warnings, added WARN_ON, made SMP only ] Signed-off-by: Peter P Waskiewicz Jr Cc: davem@davemloft.net Cc: arjan@linux.jf.intel.com Cc: bhutchings@solarflare.com LKML-Reference: <20100430214445.3992.41647.stgit@ppwaskie-hc2.jf.intel.com> Signed-off-by: Thomas Gleixner --- include/linux/interrupt.h | 6 ++++++ include/linux/irq.h | 1 + 2 files changed, 7 insertions(+) (limited to 'include') diff --git a/include/linux/interrupt.h b/include/linux/interrupt.h index e6d2f4441fda..5137db3317f9 100644 --- a/include/linux/interrupt.h +++ b/include/linux/interrupt.h @@ -233,6 +233,7 @@ extern int irq_set_affinity(unsigned int irq, const struct cpumask *cpumask); extern int irq_can_set_affinity(unsigned int irq); extern int irq_select_affinity(unsigned int irq); +extern int irq_set_affinity_hint(unsigned int irq, const struct cpumask *m); #else /* CONFIG_SMP */ static inline int irq_set_affinity(unsigned int irq, const struct cpumask *m) @@ -247,6 +248,11 @@ static inline int irq_can_set_affinity(unsigned int irq) static inline int irq_select_affinity(unsigned int irq) { return 0; } +static inline int irq_set_affinity_hint(unsigned int irq, + const struct cpumask *m) +{ + return -EINVAL; +} #endif /* CONFIG_SMP && CONFIG_GENERIC_HARDIRQS */ #ifdef CONFIG_GENERIC_HARDIRQS diff --git a/include/linux/irq.h b/include/linux/irq.h index 707ab122e2e6..c03243ad84b4 100644 --- a/include/linux/irq.h +++ b/include/linux/irq.h @@ -195,6 +195,7 @@ struct irq_desc { raw_spinlock_t lock; #ifdef CONFIG_SMP cpumask_var_t affinity; + const struct cpumask *affinity_hint; unsigned int node; #ifdef CONFIG_GENERIC_PENDING_IRQ cpumask_var_t pending_mask; -- cgit v1.2.3