Hi Yinghai, OK, I will send out v9 without the MCFG cache. Thanks! Gerry On 2012-6-21 2:03, Yinghai Lu wrote: > On Wed, Jun 20, 2012 at 1:32 AM, Jiang Liu <jiang.liu@xxxxxxxxxx> wrote: >> Hi Yinghai, >> >> Yes, I'm going to adopt solution two as you suggested. >> On the other hand, the MMCFG caching is kept due to following >> considerations: >> 1) To emit a warning message if MMCFG entries in MCFG table only >> partially covers buses under a PCI host bridge. Taku reported that >> he has a system which exhibits such a behavior. > Interesting. > that should have one overal checking after _CBA entry is added into > pci_mmcfg_list. > We limit root bus bus range after busn_alloc is there. > aka dump the bus range above mmcfg. > or user need to disable mmcfg. > > >> 2) To cross-check that MMCFG addresses returned by MCFG table and >> _CBA method are consistent if both are available (though that >> violates the PCI FW/ACPI specifications). > > now we are adding support for pci hostbridge plug. so we should better to stick > with spec instead of trying to workaround possible FW problem. > Do spoil them too much. > > my point is: MCFG is static. so the range from MCFG can not be changed after > they pass the sanity checking. > later if _CBA is trying come again with overlapping, just through that away. > then if _CBA is good, then just record the range, and later release the range > according the storage during hostbridge removal. > >> 3) In future, we may try to remove MMCFG entry constructed from >> MCFG table when hot-removing a PCI host bridge. We have some systems >> which assign a distinguish segment ID for each host bridge. In such >> a case, it may be reasonable to remove the MMCFG entry when removing >> a host bridge. > No, MCFG is static one. > >> 4) The MCFG cache should be small under normal cases. >> >> If you feel it's unnecessary to keep the cache, I will remove >> it and send out a updated version soon. > for pci host bridge support, we would touch too much thing, I would > like to limit > first round change and keep it simple, and later could optimize it if possible. > > Thanks > > Yinghai > > . > -- 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
