Messages in this thread | | | Date | Sat, 1 Aug 2015 18:33:11 +0200 | From | Borislav Petkov <> | Subject | Re: [tip:x86/mm] x86/mm/mtrr: Clean up mtrr_type_lookup() |
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On Sat, Aug 01, 2015 at 04:28:20PM +0200, Luis R. Rodriguez wrote: > I need to update this documentation to remove set_memory_wc() there as we've > learned with the MTRR --> PAT conversion that set_memory_wc() cannot be used on > IO memory, it can only be used for RAM. I am not sure if I would call it being > broken that you cannot use set_memory_*() for IO memory that may have been by > design.
Well, it doesn't really make sense to write-combine IO memory, does it? My simplistic impression is that an IO range behind which there's a device, cannot stomach any caching of IO as all commands/data accesses need to happen as they get issued...
-- Regards/Gruss, Boris.
ECO tip #101: Trim your mails when you reply. --
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