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

sys/amd64/amd64/nexus.c

@@ -87,6 +87,9 @@ 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,
@@ -128,6 +131,9 @@ 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),
@@ -458,6 +464,14 @@ 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)

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)

sys/kern/bus_if.m

@@ -493,6 +493,23 @@ METHOD int child_location_str {
 	size_t		_buflen;
 };
 
+/**
+ * @brief Allow drivers to request that an interrupt be bound to a specific
+ * CPU.
+ * 
+ * @param _dev		the parent device of @p _child
+ * @param _child	the device which allocated the resource
+ * @param _irq		the resource representing the interrupt
+ * @param _cpu		the CPU to bind the interrupt to
+ */
+METHOD int bind_intr {
+	device_t	_dev;
+	device_t	_child;
+	struct resource *_irq;
+	int		_cpu;
+} DEFAULT bus_generic_bind_intr;
+
+
 /**
  * @brief Allow (bus) drivers to specify the trigger mode and polarity
  * of the specified interrupt.

sys/kern/subr_bus.c

@@ -3221,6 +3221,23 @@ bus_generic_deactivate_resource(device_t dev, device_t child, int type,
 	return (EINVAL);
 }
 
+/**
+ * @brief Helper function for implementing BUS_BIND_INTR().
+ *
+ * This simple implementation of BUS_BIND_INTR() simply calls the
+ * BUS_BIND_INTR() method of the parent of @p dev.
+ */
+int
+bus_generic_bind_intr(device_t dev, device_t child, struct resource *irq,
+    int cpu)
+{
+
+	/* Propagate up the bus hierarchy until someone handles it. */
+	if (dev->parent)
+		return (BUS_BIND_INTR(dev->parent, child, irq, cpu));
+	return (EINVAL);
+}
+
 /**
  * @brief Helper function for implementing BUS_CONFIG_INTR().
  *
@@ -3528,6 +3545,20 @@ bus_teardown_intr(device_t dev, struct resource *r, void *cookie)
 	return (BUS_TEARDOWN_INTR(dev->parent, dev, r, cookie));
 }
 
+/**
+ * @brief Wrapper function for BUS_BIND_INTR().
+ *
+ * This function simply calls the BUS_BIND_INTR() method of the
+ * parent of @p dev.
+ */
+int
+bus_bind_intr(device_t dev, struct resource *r, int cpu)
+{
+	if (dev->parent == NULL)
+		return (EINVAL);
+	return (BUS_BIND_INTR(dev->parent, dev, r, cpu));
+}
+
 /**
  * @brief Wrapper function for BUS_SET_RESOURCE().
  *

sys/sys/bus.h

@@ -286,6 +286,8 @@ struct resource *
 				   int *rid, u_long start, u_long end,
 				   u_long count, u_int flags);
 int	bus_generic_attach(device_t dev);
+int	bus_generic_bind_intr(device_t dev, device_t child,
+			      struct resource *irq, int cpu);
 int	bus_generic_child_present(device_t dev, device_t child);
 int	bus_generic_config_intr(device_t, int, enum intr_trigger,
 				enum intr_polarity);
@@ -358,6 +360,7 @@ int	bus_setup_intr(device_t dev, struct resource *r, int flags,
 		       driver_filter_t filter, driver_intr_t handler, 
 		       void *arg, void **cookiep);
 int	bus_teardown_intr(device_t dev, struct resource *r, void *cookie);
+int	bus_bind_intr(device_t dev, struct resource *r, int cpu);
 int	bus_set_resource(device_t dev, int type, int rid,
 			 u_long start, u_long count);
 int	bus_get_resource(device_t dev, int type, int rid,