| From | Andy Lutomirski <> | Date | Fri, 20 Mar 2015 18:08:39 -0700 | Subject | Re: [PATCH v1 00/47] mtrr/x86/drivers: bury MTRR |
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On Fri, Mar 20, 2015 at 4:17 PM, Luis R. Rodriguez <mcgrof@do-not-panic.com> wrote: > From: "Luis R. Rodriguez" <mcgrof@suse.com> > > When a system has PAT support enabled you don't need to be > using MTRRs. Andy had added arch_phys_wc_add() long ago to > help with this but not all drivers were converted over. We > have to take care to only convert drivers where we know that > the proper ioremap_wc() API has been used. Doing this requires > a bit of work on verifying the driver split out the ioremap'd > areas -- and if not doing that ourselves. Verifying a driver > uses the same areas can be hard but with a bit of love Coccinelle > can help with that. > > We're motivated to change drivers for a few reasons: > > 1) Take advantage of PAT when available > > 2) Help with the goal of eventually using _PAGE_CACHE_UC over > _PAGE_CACHE_UC_MINUS on x86 on ioremap_nocache() (de33c442e)
Nice!
--Andy
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