Implement a BUS_BIND_INTR() method in the bus interface to bind an IRQ

resource to a CPU.  The default method is to pass the request up to the
parent similar to BUS_CONFIG_INTR() so that all busses don't have to
explicitly implement bus_bind_intr.  A bus_bind_intr(9) wrapper routine
similar to bus_setup/teardown_intr() is added for device drivers to use.
Unbinding an interrupt is done by binding it to NOCPU.  The IRQ resource
must be allocated, but it can happen in any order with respect to
bus_setup_intr().  Currently it is only supported on amd64 and i386 via
nexus(4) methods that simply call the intr_bind() routine.

Tested by:	gallatin

1 files changed, 14 insertions, 0 deletions

diff --git a/sys/i386/i386/nexus.c b/sys/i386/i386/nexus.c
index 0c09c3467759..98adc933a23b 100644
--- a/sys/i386/i386/nexus.c
+++ b/sys/i386/i386/nexus.c
@@ -91,6 +91,9 @@ static device_t nexus_add_child(device_t bus, int order, const char *name,
 				int unit);
 static	struct resource *nexus_alloc_resource(device_t, device_t, int, int *,
 					      u_long, u_long, u_long, u_int);
+#ifdef SMP
+static	int nexus_bind_intr(device_t, device_t, struct resource *, int);
+#endif
 static	int nexus_config_intr(device_t, int, enum intr_trigger,
 			      enum intr_polarity);
 static	int nexus_activate_resource(device_t, device_t, int, int,
@@ -134,6 +137,9 @@ static device_method_t nexus_methods[] = {
 	DEVMETHOD(bus_deactivate_resource, nexus_deactivate_resource),
 	DEVMETHOD(bus_setup_intr,	nexus_setup_intr),
 	DEVMETHOD(bus_teardown_intr,	nexus_teardown_intr),
+#ifdef SMP
+	DEVMETHOD(bus_bind_intr,	nexus_bind_intr),
+#endif
 	DEVMETHOD(bus_config_intr,	nexus_config_intr),
 	DEVMETHOD(bus_get_resource_list, nexus_get_reslist),
 	DEVMETHOD(bus_set_resource,	nexus_set_resource),
@@ -505,6 +511,14 @@ nexus_teardown_intr(device_t dev, device_t child, struct resource *r, void *ih)
 	return (intr_remove_handler(ih));
 }
 
+#ifdef SMP
+static int
+nexus_bind_intr(device_t dev, device_t child, struct resource *irq, int cpu)
+{
+	return (intr_bind(rman_get_start(irq), cpu));
+}
+#endif
+
 static int
 nexus_config_intr(device_t dev, int irq, enum intr_trigger trig,
     enum intr_polarity pol)