Messages in this thread | | | Date | Thu, 13 Sep 2007 13:14:44 -0700 | From | Yinghai Lu <> | Subject | Re: [PATCH] x86_64: set cfg_size for AMD Family 10h in case MMCONFIG is used |
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Andreas Herrmann wrote: > On Thu, Sep 13, 2007 at 01:53:15PM +0200, Andi Kleen wrote: >> On Thursday 13 September 2007 12:47, Greg KH wrote: >>> On Thu, Sep 13, 2007 at 11:47:42AM +0200, Andi Kleen wrote: >>>> On Thursday 13 September 2007 04:21, Yinghai Lu wrote: >>>>> [PATCH] x86_64: set cfg_size for AMD Family 10h in case MMCONFIG is >>>>> used. >>>>> >>>>> reuse pci_cfg_space_size but skip check pci express and pci-x CAP ID. >>>> I just rejected a similar patch -- this should be done using MMCONFIG >>> But what about for broken machines without the proper MMCONFIG entries? >>> They still need a way to get access to this config space, >> If there are any devices that need it. IBS and PCI-E error handling >> do, but they're quite obscure. >> >> Also so far we don't know of any Fam 10h systems without MMCONFIG >> entries. Fam10h requires a new BIOS so it's reasonable to assume >> that the new BIOSes will do better. > > IMHO support for all config space access methods should be added to the kernel. > And it should be added at a central point. Not waiting for drivers to do it > their own way if they need to use it. > > The more complicated/important question is how to decide which access method > should be used for a device. (Something similar to the pci_mmcfg_fallback_slots > stuff that exists already for K8 NB.) > But that needs some more thinking. > > Here a summary wrt family 10h extended config space access methods. > (Most of this stuff I verified with some patched kernels. I didn't > eavesdropping on the physical links though ...) > > For family 10h we have 3 methods > (1) "legacy" MMCONFIG access (via south bridge) > (2) mmconfig access via CPU/NB (new with fam10h, using the new MMIO > config base MSR) > (3) CF8/CFC ECS access (new with fam10h, has to be enabled in the NB_CFG MSR)
ECS access in NB_CFG_MSR is always enabled. because BIOS need to use that to do mem initialization.
mmconfig enablement in BIOS is depending ....
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