On Fri, Dec 13, 2013 at 7:35 AM, Ludwig Petrosyan <ludwig.petrosyan@xxxxxxx> wrote: > Hi All > > we are working at DESY (Deutsches Elektronen-Synchrotron, Hamburg Germany) > and involved in evaluation of MTCA.4 standard (MTCA for Physics) > I have question concerning PCIe hotplag: > The Hot-Swap is working, I mean, if there was a PCIe endpoint card in > the PCIe slot this module could be later removed and inserted back in > running system. But if the Slot was empty and one insert the new PCIe > endpoint card in slot, the card will be connected in PCIe bus (I could > see it in lspci) but memory not enabled. Only after rebooting of the OS > the memory will be enabled. > For MTCA.4 standard it is very important to have possibility to add new > PCIe endpoint card in running system. > So, my question is: > is there some OS boot parameter I could reserve memory for all PCIe > ports which hase slot implemented (if slot implemented on the PCIe > switch or RootComplex port this means later could be some PCIe endpoint > card inserted) If a Root Port or switch Downstream Port has the PCI_EXP_SLTCAP_HPC (Slot Capabilities Hot-Plug Capable) bit is set, Linux should reserve 2MB for the port's MMIO aperture. That isn't very much, but you can change that amount with the "pci=hpmemsize=" boot option. And I think if you have firmware that configures a larger aperture, Linux will keep that. A complete dmesg log and "lspci -vv" output would be the place to start investigating if Linux isn't doing this correctly. Bjorn -- To unsubscribe from this list: send the line "unsubscribe linux-pci" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
