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authorMarc Zyngier <maz@misterjones.org>2010-03-15 22:56:33 +0000
committerThomas Gleixner <tglx@linutronix.de>2010-04-13 16:36:39 +0200
commitae731f8d0785ccd3380f511bae888933b6562e45 (patch)
tree07db03ce79231153a4ae5df75c0ca4dcd96307c2 /include/linux/interrupt.h
parent7c7145f6acc68100dbdc5d3c5c64fe3af1c99c89 (diff)
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 <maz@misterjones.org> Cc: <joachim.eastwood@jotron.com> LKML-Reference: <927ea285bd0c68934ddae1a47e44a9ba@localhost> Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Diffstat (limited to 'include/linux/interrupt.h')
-rw-r--r--include/linux/interrupt.h23
1 files changed, 23 insertions, 0 deletions
diff --git a/include/linux/interrupt.h b/include/linux/interrupt.h
index 75f3f00ac1e..d7e7a7660c6 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