misc questions about the device&driver arch

[kylin]

hello every one :) good day!
i have list the 3 puzzle coming to me in my recent coding reading of freebsd
0
///////////////
pci bridge dynamic resize
/////////////
it seems that the device arch of freebsd is similar to what is revealed in
window OS. i have read the pcie hotplug tps of windows longhorn ,it is said
that with some hardware mechanisms the pci bridge driver can do global pci
resource window reconfiguration.so good to the hotplugin pci device for it
avoid prelocating resource for the device .
i wonder ,if the mem /io/irq reconfiguration possible under freebsd .:)
 1
//////////////
 is bus_data_generation
/////////
what idoes bus_data_generation for, is it the generation count for the
device manager tree?
void
bus_data_generation_update(void)
{
bus_data_generation++;
}
 2
//////////////
pci_write_config vs pci_write_config_method
//////////////
under the source code /dev/pci .there are functions name pci_write_config (
pcivar.h) and pci_write_config_method(pci.c)
they both call the parent method ,though the content is different ,but does
that a liitle overlap whit each other?

--
we who r about to die,salute u!