Date: Tue, 12 Mar 2013 08:08:59 +0200 From: Konstantin Belousov <kostikbel@gmail.com> To: Jim Harris <jimharris@freebsd.org> Cc: Dag-Erling Sm??rgrav <des@des.no>, Lev Serebryakov <lev@serebryakov.spb.ru>, arch@freebsd.org Subject: Re: Unmapped buffers: to be merged in several days Message-ID: <20130312060859.GI3794@kib.kiev.ua> In-Reply-To: <CAJP=Hc9V9HVpdevD3=Qgk812CYwbmc-Q4HgtPyupb7zTfmTB6g@mail.gmail.com> References: <20130311091852.GR3794@kib.kiev.ua> <86k3pe1cl3.fsf@ds4.des.no> <20130311182454.GX3794@kib.kiev.ua> <329178079.20130312010425@serebryakov.spb.ru> <20130311211158.GE3794@kib.kiev.ua> <CAJP=Hc9V9HVpdevD3=Qgk812CYwbmc-Q4HgtPyupb7zTfmTB6g@mail.gmail.com>
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--3lO0Bl7Vyth644rr Content-Type: text/plain; charset=us-ascii Content-Disposition: inline Content-Transfer-Encoding: quoted-printable On Mon, Mar 11, 2013 at 03:22:47PM -0700, Jim Harris wrote: > On Mon, Mar 11, 2013 at 2:11 PM, Konstantin Belousov <kostikbel@gmail.com= >wrote: >=20 > > FWIW, I tried to get an Intel documentation for IOAT engine which should > > allow to perform the XOR checksumming of the unmapped buffers, suitable > > for e.g. hardware-assisted software raid5, but did not succeeded. > > >=20 > Please note that XOR checksumming support only exists in the > E5-1600/2400/2600/4600 series (Sandy Bridge Xeon) and C5500/C3500 series > (Jasper Forest - based on Nehalem Xeon) processors. The SNB Xeon series > EDS section for IOAT isn't public, but the Jasper Forest datasheet volume= 2 > does contain the register interfaces. See sections 3.9 and section 3.10. > The ioat HW interface for XOR is the same for both series save for some > delta in errata. >=20 > http://www.intel.com/content/dam/www/public/us/en/documents/datasheets/xe= on-c5500-c3500-datasheet-vol-2.pdf Thank you for this pointer too. I remember from looking at the e5-1600 registers description, that all magic happens in the channel commands, which specifications are absent in the chipset documentation. >=20 > Also note there is an ioat driver (DMA operations only) on the > user/jimharris/ioat branch in the FreeBSD SVN repo. The Linux ioat driver > with XOR support is dual-licensed BSD/GPL. >=20 Yes, I did some reading of this code. --3lO0Bl7Vyth644rr Content-Type: application/pgp-signature -----BEGIN PGP SIGNATURE----- Version: GnuPG v2.0.19 (FreeBSD) iQIcBAEBAgAGBQJRPsZ7AAoJEJDCuSvBvK1B6+EQAJns14Gy3UCBwlRFseY0rK9C /Mh8FeJPRISuiBLDNg8RrIU3qI4ApZRzCw6lYqdlM5LslliiIOArsXR2rQuxm7D3 hUmXEEfAoiRqKmhLZKX/yUC8hjq/dhK8s5nRraJVscQbrkgl4vrm6esdARoeJkH7 RbrCcCOA/2dVNnJi7CRuMlhU3kLXfHwcw5pBgajXCP3fvX//xYadM2uADjuvWOG8 NL8Gky7YsLB/P0On7pxMFTi9FmlJ0QHk0BfzfAiyAjzxvyRmXdFtPeWRQBTmxYDl AzsES62QnBWtkgGOhCszbOqed5JMw+eCjbML5XqcoJY9n9Qgs+Ej0Pkme1eWAO2j CV6+Lh4/gWj/sbjjG4H6N0W0qGn2ignqotfyw5TT8x7P37Ldb2iqE0yaZjg9lYEl 1xNsXnV9Bgfmy0Z5+4LpCwbOkJyZWqldnT6BTlDLLfnnTyn8VwEuSjkbZ2JcQYQv 0vMzGULp5O8SlKJqtBfc8/hk2mdxJsaEus9Vy6ivzbSE/1N5PTlZ4Zj2E/+4D01x hBXoOWWnFhPa1E3086o0+rF3plgMYXihpvj2wiGlJe/8B1pkSeNIq3cgknBcOES7 T1myRzyDGmFsuBDxYbc7KRtyOL9q9KhoWeajlEOq+zCK5XYden8zzwUODaLYn/Lq 5v2EuyjLT0g/DbkJOODm =hDZ8 -----END PGP SIGNATURE----- --3lO0Bl7Vyth644rr--
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