svn commit: r323032 - in head: share/man/man4 sys/amd64/conf sys/conf sys/dev/ntb/ntb_hw sys/i386/conf sys/modules/ntb sys/modules/ntb/ntb_hw sys/modules/ntb/ntb_hw_intel sys/modules/ntb/ntb_hw_plx

[Konstantin Belousov]

On Thu, Aug 31, 2017 at 07:12:38PM +0300, Alexander Motin wrote:
> On 31.08.2017 19:05, Konstantin Belousov wrote:
> > On Wed, Aug 30, 2017 at 09:16:32PM +0000, Alexander Motin wrote:
> >> Author: mav
> >> Date: Wed Aug 30 21:16:32 2017
> >> New Revision: 323032
> >> URL: https://svnweb.freebsd.org/changeset/base/323032
> >>
> >> Log:
> >>   Add NTB driver for PLX/Avago/Broadcom PCIe switches.
> >>   
> > In ntb_plx_attach(), BAR 0 and all found BARs 2-5 are explicitely
> > remapped as uncacheable.  Why is it needed ?  Does rman on x86
> > ever map any resource as not non-cacheable ?
> 
> Hmm.  May be not.  I added those to be sure while debugging one issue,
> which appeared unrelated.  Shall I remove them, expecting non-cacheable
> to be default there?
Unless you need some other mode on the windows, e.g. write-combining,
I do not see a use for re-applying the same mapping attributes.  The
pmap function is somewhat optimized, but it still had to iterate over
the page table.