From mboxrd@z Thu Jan 1 00:00:00 1970 From: Arnd Bergmann Subject: Re: Multi-platform, and secure-only ARM errata workarounds Date: Tue, 26 Feb 2013 10:48:06 +0000 Message-ID: <201302261048.06644.arnd@arndb.de> References: <512BF81A.3080700@wwwdotorg.org> <20130226103114.GA16875@arm.com> <20130226103503.GB16875@arm.com> Mime-Version: 1.0 Content-Type: Text/Plain; charset="iso-8859-1" Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <20130226103503.GB16875-5wv7dgnIgG8@public.gmane.org> Sender: linux-tegra-owner-u79uwXL29TY76Z2rM5mHXA@public.gmane.org To: Catalin Marinas Cc: Russell King , Stephen Warren , "rob.herring-bsGFqQB8/DxBDgjK7y7TUQ@public.gmane.org" , Olof Johansson , "linux-tegra-u79uwXL29TY76Z2rM5mHXA@public.gmane.org" , ARM kernel mailing list List-Id: linux-tegra@vger.kernel.org On Tuesday 26 February 2013, Catalin Marinas wrote: > On Tue, Feb 26, 2013 at 10:31:14AM +0000, Catalin Marinas wrote: > > On Tue, Feb 26, 2013 at 10:23:26AM +0000, Arnd Bergmann wrote: > > > On Monday 25 February 2013, Stephen Warren wrote: > > > > Is there any other alternative I'm not seeing? Having the kernel > > > > suddenly become incompatible with any currently extant bootloader when I > > > > enable CONFIG_MULTIPLATFORM doesn't seem like a great idea. > > > > > > Could we make those errata be run-time enabled only when not booting > > > in secure mode? > > > > There is no easy way to detect whether Linux booted in secure mode, > > unless we add some information in the DT. But I wouldn't add S vs NS > > information, rather which errata need to be enabled by the kernel. > > Another difficulty - parsing the DT is done later while some workarounds > are enabled before the MMU (or require the MMU to be disabled > temporarily). Can we do it easily after detecting the machine_desc? Maybe we could add a bit mask of errata to the struct. Arnd