1config NTB_IDT 2 tristate "IDT PCIe-switch Non-Transparent Bridge support" 3 depends on PCI 4 select HWMON 5 help 6 This driver supports NTB of cappable IDT PCIe-switches. 7 8 Some of the pre-initializations must be made before IDT PCIe-switch 9 exposes it NT-functions correctly. It should be done by either proper 10 initialisation of EEPROM connected to master smbus of the switch or 11 by BIOS using slave-SMBus interface changing corresponding registers 12 value. Evidently it must be done before PCI bus enumeration is 13 finished in Linux kernel. 14 15 First of all partitions must be activated and properly assigned to all 16 the ports with NT-functions intended to be activated (see SWPARTxCTL 17 and SWPORTxCTL registers). Then all NT-function BARs must be enabled 18 with chosen valid aperture. For memory windows related BARs the 19 aperture settings shall determine the maximum size of memory windows 20 accepted by a BAR. Note that BAR0 must map PCI configuration space 21 registers. 22 23 It's worth to note, that since a part of this driver relies on the 24 BAR settings of peer NT-functions, the BAR setups can't be done over 25 kernel PCI fixups. That's why the alternative pre-initialization 26 techniques like BIOS using SMBus interface or EEPROM should be 27 utilized. 28 29 If unsure, say N. 30 31