lspci -tv

decoding … 0000.00.18.1
Advanced Micro Devices [AMD] K8 [Athlon64/Opteron] Address Map

0000 : PCI domain (each domain can contain up to 256 PCI buses)
00 : the bus number the device is attached to
18 : the device number
.1 : PCI device function

http://froisa.com/wp-content/uploads/2010/04/lspci-tv.txt