MFC 261790:

Add support for managing PCI bus numbers.  As with BARs and PCI-PCI bridge
I/O windows, the default is to preserve the firmware-assigned resources.
PCI bus numbers are only managed if NEW_PCIB is enabled and the architecture
defines a PCI_RES_BUS resource type.
- Add a helper API to create top-level PCI bus resource managers for each
  PCI domain/segment.  Host-PCI bridge drivers use this API to allocate
  bus numbers from their associated domain.
- Change the PCI bus and CardBus drivers to allocate a bus resource for
  their bus number from the parent PCI bridge device.
- Change the PCI-PCI and PCI-CardBus bridge drivers to allocate the
  full range of bus numbers from secbus to subbus from their parent bridge.
  The drivers also always program their primary bus register.  The bridge
  drivers also support growing their bus range by extending the bus resource
  and updating subbus to match the larger range.
- Add support for managing PCI bus resources to the Host-PCI bridge drivers
  used for amd64 and i386 (acpi_pcib, mptable_pcib, legacy_pcib, and qpi_pcib).
- Define a PCI_RES_BUS resource type for amd64 and i386.

PR:		197076

2 files changed, 22 insertions, 0 deletions

diff --git a/sys/dev/cardbus/cardbus.c b/sys/dev/cardbus/cardbus.c
index 608c1fe..00d4a19 100644
--- a/sys/dev/cardbus/cardbus.c
+++ b/sys/dev/cardbus/cardbus.c
@@ -96,17 +96,36 @@ static int
 cardbus_attach(device_t cbdev)
 {
 	struct cardbus_softc *sc;
+#ifdef PCI_RES_BUS
+	int rid;
+#endif
 
 	sc = device_get_softc(cbdev);
 	sc->sc_dev = cbdev;
+#ifdef PCI_RES_BUS
+	rid = 0;
+	sc->sc_bus = bus_alloc_resource(cbdev, PCI_RES_BUS, &rid,
+	    pcib_get_bus(cbdev), pcib_get_bus(cbdev), 1, 0);
+	if (sc->sc_bus == NULL) {
+		device_printf(cbdev, "failed to allocate bus number\n");
+		return (ENXIO);
+	}
+#endif
 	return (0);
 }
 
 static int
 cardbus_detach(device_t cbdev)
 {
+#ifdef PCI_RES_BUS
+	struct cardbus_softc *sc;
+#endif
 
 	cardbus_detach_card(cbdev);
+#ifdef PCI_RES_BUS
+	sc = device_get_softc(cbdev);
+	(void)bus_release_resource(cbdev, PCI_RES_BUS, 0, sc->sc_bus);
+#endif
 	return (0);
 }
 
diff --git a/sys/dev/cardbus/cardbusvar.h b/sys/dev/cardbus/cardbusvar.h
index 6264f69..7730ffd 100644
--- a/sys/dev/cardbus/cardbusvar.h
+++ b/sys/dev/cardbus/cardbusvar.h
@@ -69,6 +69,9 @@ struct cardbus_devinfo
 struct cardbus_softc 
 {
 	device_t	sc_dev;
+#ifdef PCI_RES_BUS
+	struct resource *sc_bus;
+#endif
 };
 
 /*