From mboxrd@z Thu Jan 1 00:00:00 1970 From: Tony Lindgren Subject: Re: runtime check for omap-aes bus access permission (was: Re: 3.13-rc3 (commit 7ce93f3) breaks Nokia N900 DT boot) Date: Sat, 7 Dec 2013 13:11:37 -0800 Message-ID: <20131207211137.GR26766@atomide.com> References: <20131206213613.GA19648@earth.universe> <201312070918.32471@pali> <20131207134818.GA933@earth.universe> <201312071457.38836@pali> <20131207165104.GD11015@atomide.com> <20131207184958.GB3704@earth.universe> Mime-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: QUOTED-PRINTABLE Return-path: Received: from mho-03-ewr.mailhop.org ([204.13.248.66]:21041 "EHLO mho-01-ewr.mailhop.org" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1754375Ab3LGVLk (ORCPT ); Sat, 7 Dec 2013 16:11:40 -0500 Content-Disposition: inline In-Reply-To: <20131207184958.GB3704@earth.universe> Sender: linux-omap-owner@vger.kernel.org List-Id: linux-omap@vger.kernel.org To: Pali =?utf-8?B?Um9ow6Fy?= , linux-omap@vger.kernel.org, Aaro Koskinen , Joel Fernandes * Sebastian Reichel [131207 10:51]: > On Sat, Dec 07, 2013 at 08:51:04AM -0800, Tony Lindgren wrote: > > * Pali Roh=C3=A1r [131207 05:58]: > > > On Saturday 07 December 2013 14:48:20 Sebastian Reichel wrote: > > > > On Sat, Dec 07, 2013 at 09:18:32AM +0100, Pali Roh=C3=A1r wrote= : > > > > > On Saturday 07 December 2013 01:00:27 Sebastian Reichel=20 > > > wrote: > > > > > > On Fri, Dec 06, 2013 at 02:27:25PM -0800, Tony Lindgren=20 > > > wrote: > > > > > > > * Sebastian Reichel [131206 13:37]: > > > > > > > > Nokia N900 DT boot breaks for me using 3.13-rc3. You > > > > > > > > can see the relevant kernel output below. Disabling > > > > > > > > the AES module in the omap3-n900.dts with status =3D > > > > > > > > "disabled" fixed the boot for me. > > > > > > >=20 > > > > > > > OK thanks for letting me know. How about the following > > > > > > > patch to fix it? > > > > > >=20 > > > > > > That's basically what I did to fix the problem. > > > > > >=20 > > > > > > I guess the proper fix would be a runtime check if the > > > > > > device can be accessed (if that's possible). AFAIK it is > > > > > > possible to use the AES module on the N900 if the > > > > > > bootloader is slightly patched. > > > > > >=20 > > > > > > Pali, can you elaborate more about this? I've seen, that > > > > > > you added a section about this on [0]. > > > > > >=20 > > > > > > [0] http://elinux.org/N900#M-Shield > > > > > >=20 > > > > > > -- Sebastian > > > > >=20 > > > > > Yes, if you want to use M-Shield on Nokia N900, you need to > > > > > use new version of signed Nokia X-Loader which enable > > > > > M-Shield usage outside secure world. > > > > >=20 > > > > > Because this updated X-Loader is not official and I think > > > > > nobody has it in n900, please disable using these M-Shield > > > > > crypto modules on n900. > > > >=20 > > > > Is the updated X-Loader available somewhere? > > > >=20 > > >=20 > > > It was on mediafire server linked from this thread:=20 > > > http://maemo.org/community/maemo-developers/n900_aes_and_sha1-md5= _hw_acceleration_drivers/ > > > > > > Now it is deleted from that server, but I have copy on my HDD. > >=20 > > Hmm OK let's hope there's some working link still around for those. > > It seems like we should eventually cover both options, but for > > the -rc cycle, we need to just disable those hardware modules in > > the .dtsi files. >=20 > Yes. I think for -rc cycle disabling the AES module is the right > way. It has been disabled before anyway. I will test your patch > later. OK thanks. =20 > > I think we can check the configuration from the L3 registers. > > Looks like we no longer have those defined after purging the > > unused defines a while back, but I think the registers for the > > configuration are L3_PM_READ_PERMISSION etc registers. >=20 > I asked Pali to send me his copy of the updated NOLO bootloader, > so that I can test this. I just checked the omap documentation > (I only have access to the public one) and crypto related stuff > is not documented for the L3_PM_READ_PERMISSION register. There > are a couple of reserved bits, which may be used for this, though. >=20 > I also CC'd Joel Fernandes, since he worked on the driver before and > may have access to the documentation. Looks like at least the 36xx public version referenced here has them: http://www.spinics.net/lists/linux-omap/msg21857.html I'd assume the registers are the same for 34xx since we don't have them defined separately in the kernel. Regards, Tony -- To unsubscribe from this list: send the line "unsubscribe linux-omap" i= n the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html