This patch lets interrupt handler functions have their natural type
(ie. exactly match the data pointer type); for transition it allows
the old irq_handler_t type as well.
To do this it uses a gcc extension, cast-to-union, which allows a type
to be cast to any type within the union. When used in a wrapper
macro, it's a simple way of allowing one of several types.
(Some drivers now need to be cleaned up to compile, previous patch).
Signed-off-by: Rusty Russell <rusty@xxxxxxxxxxxxxxx>
---
include/linux/interrupt.h | 17 +++++++++++++++--
include/linux/kernel.h | 7 +++++++
kernel/irq/devres.c | 10 +++++-----
kernel/irq/manage.c | 6 +++---
4 files changed, 30 insertions(+), 10 deletions(-)
diff -r 0fe1a980708b include/linux/interrupt.h
--- a/include/linux/interrupt.h Thu Jan 17 14:48:56 2008 +1100
+++ b/include/linux/interrupt.h Thu Jan 17 15:42:01 2008 +1100
@@ -69,13 +69,26 @@ struct irqaction {
};
extern irqreturn_t no_action(int cpl, void *dev_id);
-extern int __must_check request_irq(unsigned int, irq_handler_t handler,
+
+/* Typesafe version of request_irq. Also takes old-style void * handlers. */
+#define request_irq(irq, handler, flags, name, dev_id) \
+ __request_irq((irq), \
+ check_either_type((handler), irq_handler_t, \
+ int (*)(int, typeof(dev_id))), \
+ (flags), (name), (dev_id))
+
+extern int __must_check __request_irq(unsigned int, irq_handler_t handler,
unsigned long, const char *, void *);
extern void free_irq(unsigned int, void *);
struct device;
-extern int __must_check devm_request_irq(struct device *dev, unsigned int irq,
+#define devm_request_irq(dev, irq, handler, flags, name, dev_id) \
+ __devm_request_irq((dev), (irq), \
+ check_either_type((handler), irq_handler_t, \
+ int (*)(int, typeof(dev_id))), \
+ (flags), (name), (dev_id))
+extern int __must_check __devm_request_irq(struct device *dev, unsigned int irq,
irq_handler_t handler, unsigned long irqflags,
const char *devname, void *dev_id);
extern void devm_free_irq(struct device *dev, unsigned int irq, void *dev_id);
diff -r 0fe1a980708b include/linux/kernel.h
--- a/include/linux/kernel.h Thu Jan 17 14:48:56 2008 +1100
+++ b/include/linux/kernel.h Thu Jan 17 15:42:01 2008 +1100
@@ -379,6 +379,13 @@ static inline int __attribute__ ((format
(void)__tmp; \
})
+/*
+ * Returns var as a type1. If it's not a type1 or type2 you'll get:
+ * "error: cast to union type from type not present in union"
+ */
+#define check_either_type(var, type1, type2) \
+ (((union { typeof(type1) _t1; typeof(type2) _t2; })var)._t1)
+
struct sysinfo;
extern int do_sysinfo(struct sysinfo *info);
diff -r 0fe1a980708b kernel/irq/devres.c
--- a/kernel/irq/devres.c Thu Jan 17 14:48:56 2008 +1100
+++ b/kernel/irq/devres.c Thu Jan 17 15:42:01 2008 +1100
@@ -41,9 +41,9 @@ static int devm_irq_match(struct device
* If an IRQ allocated with this function needs to be freed
* separately, dev_free_irq() must be used.
*/
-int devm_request_irq(struct device *dev, unsigned int irq,
- irq_handler_t handler, unsigned long irqflags,
- const char *devname, void *dev_id)
+int __devm_request_irq(struct device *dev, unsigned int irq,
+ irq_handler_t handler, unsigned long irqflags,
+ const char *devname, void *dev_id)
{
struct irq_devres *dr;
int rc;
@@ -53,7 +53,7 @@ int devm_request_irq(struct device *dev,
if (!dr)
return -ENOMEM;
- rc = request_irq(irq, handler, irqflags, devname, dev_id);
+ rc = __request_irq(irq, handler, irqflags, devname, dev_id);
if (rc) {
devres_free(dr);
return rc;
@@ -65,7 +65,7 @@ int devm_request_irq(struct device *dev,
return 0;
}
-EXPORT_SYMBOL(devm_request_irq);
+EXPORT_SYMBOL(__devm_request_irq);
/**
* devm_free_irq - free an interrupt
diff -r 0fe1a980708b kernel/irq/manage.c
--- a/kernel/irq/manage.c Thu Jan 17 14:48:56 2008 +1100
+++ b/kernel/irq/manage.c Thu Jan 17 15:42:01 2008 +1100
@@ -514,8 +514,8 @@ EXPORT_SYMBOL(free_irq);
* IRQF_SAMPLE_RANDOM The interrupt can be used for entropy
*
*/
-int request_irq(unsigned int irq, irq_handler_t handler,
- unsigned long irqflags, const char *devname, void *dev_id)
+int __request_irq(unsigned int irq, irq_handler_t handler,
+ unsigned long irqflags, const char *devname, void *dev_id)
{
struct irqaction *action;
int retval;
@@ -576,4 +576,4 @@ int request_irq(unsigned int irq, irq_ha
return retval;
}
-EXPORT_SYMBOL(request_irq);
+EXPORT_SYMBOL(__request_irq);
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