From mboxrd@z Thu Jan 1 00:00:00 1970 From: catalin.marinas@arm.com (Catalin Marinas) Date: Tue, 23 Mar 2010 10:04:14 +0000 Subject: [RFC 17/18] arm: mm: Add SW emulation for ARM domain manager feature In-Reply-To: References: <1263250057-26692-18-git-send-email-dwalker@codeaurora.org> <1264437609.6275.110.camel@pc1117.cambridge.arm.com> <1269281511.31379.53.camel@c-dwalke-linux.qualcomm.com> <1269288091.31379.57.camel@c-dwalke-linux.qualcomm.com> Message-ID: <1269338654.29545.26.camel@e102109-lin.cambridge.arm.com> To: linux-arm-kernel@lists.infradead.org List-Id: linux-arm-kernel.lists.infradead.org On Mon, 2010-03-22 at 20:32 +0000, Nicolas Pitre wrote: > On Mon, 22 Mar 2010, Daniel Walker wrote: > > > On Mon, 2010-03-22 at 14:58 -0400, Nicolas Pitre wrote: > > > On Mon, 22 Mar 2010, Daniel Walker wrote: > > > > > > > On Mon, 2010-01-25 at 16:40 +0000, Catalin Marinas wrote: > > > > > Hi Daniel, > > > > > > > > > > On Mon, 2010-01-11 at 22:47 +0000, Daniel Walker wrote: > > > > > > Do not set domain manager bits in cp15 dacr. Emulate using SW. Add > > > > > > kernel hooks to handle domain changes, permission faults, and context > > > > > > switches. > > > > > > > > > > In case you were not aware, there's a patch around (I think since 2007) > > > > > that removes the domain switching entirely from the kernel (given that > > > > > they have been deprecated for some time and may disappear completely in > > > > > the future): > > > > > > > > > > http://lists.infradead.org/pipermail/linux-arm-kernel/2009-December/005616.html > > > > > > > > > > > > > I didn't find this in 2.6.34 ? Are you re-writing it? Why has it been > > > > around so long out of mainline? > > > > > > Because no real hardware out there needed it until recently, i.e. > > > inertia. > > > > Current MSM hardware needs it, just to cover up a defect in the > > processor. At least that's what this thread was originally about. > > Some other processors should need it too for some architecturally > defined reasons. Would be a good thing if you could remove your > emulation and replace it with this patch, and confirm it works for you > by providing Tested-by tags. I posted an up-to-date patch yesterday or you can grab it from my devel branch - http://www.linux-arm.org/git?p=linux-2.6.git;a=shortlog;h=refs/heads/devel (the master branch on his tree is the same, only that it's merge-friendly rather than rebased but the git server got a bit slower I think because git gc stopped few some months ago). -- Catalin