1config NTB_IDT 2 tristate "IDT PCIe-switch Non-Transparent Bridge support" 3 depends on PCI 4 help 5 This driver supports NTB of cappable IDT PCIe-switches. 6 7 Some of the pre-initializations must be made before IDT PCIe-switch 8 exposes it NT-functions correctly. It should be done by either proper 9 initialisation of EEPROM connected to master smbus of the switch or 10 by BIOS using slave-SMBus interface changing corresponding registers 11 value. Evidently it must be done before PCI bus enumeration is 12 finished in Linux kernel. 13 14 First of all partitions must be activated and properly assigned to all 15 the ports with NT-functions intended to be activated (see SWPARTxCTL 16 and SWPORTxCTL registers). Then all NT-function BARs must be enabled 17 with chosen valid aperture. For memory windows related BARs the 18 aperture settings shall determine the maximum size of memory windows 19 accepted by a BAR. Note that BAR0 must map PCI configuration space 20 registers. 21 22 It's worth to note, that since a part of this driver relies on the 23 BAR settings of peer NT-functions, the BAR setups can't be done over 24 kernel PCI fixups. That's why the alternative pre-initialization 25 techniques like BIOS using SMBus interface or EEPROM should be 26 utilized. Additionally if one needs to have temperature sensor 27 information printed to system log, the corresponding registers must 28 be initialized within BIOS/EEPROM as well. 29 30 If unsure, say N. 31 32