lkml.org 
[lkml]   [2016]   [Mar]   [4]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
Date
From
SubjectRe: [PATCH v2] x86: PAT: Documentation: rewrite "MTRR effects on PAT / non-PAT systems"
On Fri, Mar 04, 2016 at 04:03:04PM -0800, Paul E. McKenney wrote:
> On Fri, Mar 04, 2016 at 02:45:01PM -0800, Luis R. Rodriguez wrote:
> > The current documentation refers to using set_memory_wc() as a
> > possible hole strategy when you have overlapping ioremap() regions,
> > that's incorrect as set_memory_*() helpers can only be used on RAM,
> > not IO memory. Using set_memory_wc() will not fail, that's a problem
> > which must be corrected in the future. This fixes that, and updates
> > the documention to *strongly* discourage overlapping ioremap() memory
> > uses, but also documents a possible solution should there really be
> > no other option to remain compatible on both PAT and MTRR memory
> > constarained systems. While at it, this provides some same guidlines
> > to system designers to remain sane and compatible on both PAT and
> > non-PAT systems.
> >
> > As per Toshi this also fixes the table for the effective memory type
> > when using MTRR WC on PAT UC- to WC.
> >
> > Signed-off-by: Luis R. Rodriguez <mcgrof@kernel.org>
>
> And I was really confused during my earlier reply. For some reason
> I read the filename as memory-barriers.txt.
>
> This one is not mine. Too much time in standards committee meetings,
> I guess. ;-)

Heh, OK yeah I was confused why you wanted to pick it up but played along.
Boris, can this go through you as its a follow up that previously went
through you ?

Luis

\
 
 \ /
  Last update: 2016-03-05 02:41    [W:0.068 / U:0.880 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site