From 5878eb3fca650e2f20205a49181440a7f2ab680e Mon Sep 17 00:00:00 2001
From: Warner Losh <imp@FreeBSD.org>
Date: Sun, 21 Jul 2002 03:28:43 +0000
Subject: [PATCH] Add bus_child_present and the child_present method to
 bus_if.m

---
 sys/kern/bus_if.m   | 15 +++++++++++----
 sys/kern/subr_bus.c | 26 ++++++++++++++++++++++++++
 sys/sys/bus.h       |  2 ++
 3 files changed, 39 insertions(+), 4 deletions(-)

diff --git a/sys/kern/bus_if.m b/sys/kern/bus_if.m
index bf8d4ac1ee7e..c5350beaf9c9 100644
--- a/sys/kern/bus_if.m
+++ b/sys/kern/bus_if.m
@@ -36,11 +36,10 @@ INTERFACE bus;
 CODE {
 	static struct resource *
 	null_alloc_resource(device_t dev, device_t child,
-			    int type, int *rid,
-			    u_long start, u_long end,
-			    u_long count, u_int flags)
+	    int type, int *rid, u_long start, u_long end,
+	    u_long count, u_int flags)
 	{
-	    return 0;
+	    return (0);
 	}
 };
 
@@ -244,3 +243,11 @@ METHOD struct resource_list * get_resource_list {
 	device_t	_dev;
 	device_t	_child;
 } DEFAULT bus_generic_get_resource_list;
+
+#
+# Is the hardware described by _child still attached to the system?
+#
+METHOD int child_present {
+	device_t	_dev;
+	device_t	_child;
+} DEFAULT bus_generic_child_present;
diff --git a/sys/kern/subr_bus.c b/sys/kern/subr_bus.c
index 72810519f0ce..7e7df14360c1 100644
--- a/sys/kern/subr_bus.c
+++ b/sys/kern/subr_bus.c
@@ -1594,6 +1594,12 @@ bus_generic_rl_alloc_resource (device_t dev, device_t child, int type,
 	    start, end, count, flags));
 }
 
+int
+bus_generic_child_present(device_t bus, device_t child)
+{
+	return (BUS_CHILD_PRESENT(device_get_parent(bus), bus));
+}
+
 /*
  * Some convenience functions to make it easier for drivers to use the
  * resource-management functions.  All these really do is hide the
@@ -1701,6 +1707,12 @@ bus_delete_resource(device_t dev, int type, int rid)
 	BUS_DELETE_RESOURCE(device_get_parent(dev), dev, type, rid);
 }
 
+int
+bus_child_present(device_t dev)
+{
+	return (BUS_CHILD_PRESENT(device_get_parent(dev), dev));
+}
+
 static int
 root_print_child(device_t dev, device_t child)
 {
@@ -1722,6 +1734,19 @@ root_setup_intr(device_t dev, device_t child, driver_intr_t *intr, void *arg,
 	panic("root_setup_intr");
 }
 
+/*
+ * If we get here, assume that the device is permanant and really is
+ * present in the system.  Removable bus drivers are expected to intercept
+ * this call long before it gets here.  We return -1 so that drivers that
+ * really care can check vs -1 or some ERRNO returned higher in the food
+ * chain.
+ */
+static int
+root_child_present(device_t dev, device_t child)
+{
+	return (-1);
+}
+
 static kobj_method_t root_methods[] = {
 	/* Device interface */
 	KOBJMETHOD(device_shutdown,	bus_generic_shutdown),
@@ -1733,6 +1758,7 @@ static kobj_method_t root_methods[] = {
 	KOBJMETHOD(bus_read_ivar,	bus_generic_read_ivar),
 	KOBJMETHOD(bus_write_ivar,	bus_generic_write_ivar),
 	KOBJMETHOD(bus_setup_intr,	root_setup_intr),
+	KOBJMETHOD(bus_child_present,	root_child_present),
 
 	{ 0, 0 }
 };
diff --git a/sys/sys/bus.h b/sys/sys/bus.h
index 47bea4cf31ba..1559c41f1f5b 100644
--- a/sys/sys/bus.h
+++ b/sys/sys/bus.h
@@ -209,6 +209,7 @@ 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_child_present(device_t dev, device_t child);
 int	bus_generic_deactivate_resource(device_t dev, device_t child, int type,
 					int rid, struct resource *r);
 int	bus_generic_detach(device_t dev);
@@ -269,6 +270,7 @@ int	bus_get_resource(device_t dev, int type, int rid,
 u_long	bus_get_resource_start(device_t dev, int type, int rid);
 u_long	bus_get_resource_count(device_t dev, int type, int rid);
 void	bus_delete_resource(device_t dev, int type, int rid);
+int	bus_child_present(device_t dev);
 
 /*
  * Access functions for device.