From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:54386) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1XoXyT-0000gR-5p for qemu-devel@nongnu.org; Wed, 12 Nov 2014 08:28:47 -0500 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1XoXyM-00023p-RU for qemu-devel@nongnu.org; Wed, 12 Nov 2014 08:28:40 -0500 Received: from mx1.redhat.com ([209.132.183.28]:42525) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1XoXyM-00023d-Ij for qemu-devel@nongnu.org; Wed, 12 Nov 2014 08:28:34 -0500 Message-ID: <5463605D.3030801@redhat.com> Date: Wed, 12 Nov 2014 14:27:57 +0100 From: Paolo Bonzini MIME-Version: 1.0 References: <1414691045-4793-1-git-send-email-a.spyridakis@virtualopensystems.com> <20141112121809.GF28015@leverpostej> <54635222.5000700@redhat.com> <1438128.mUADeIQqjy@wuerfel> In-Reply-To: <1438128.mUADeIQqjy@wuerfel> Content-Type: text/plain; charset=windows-1252 Content-Transfer-Encoding: 8bit Subject: Re: [Qemu-devel] [Linaro-acpi] [RFC PATCH 0/7] hw/arm/virt: Dynamic ACPI v5.1 table generation List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: Arnd Bergmann Cc: Mark Rutland , Peter Maydell , "linaro-acpi@lists.linaro.org" , Paul Mundt , Claudio Fontana , QEMU Developers , Jani Kokkonen , "tech@virtualopensystems.com" , Christoffer Dall On 12/11/2014 14:08, Arnd Bergmann wrote: >>> Putting an interrupt in DT is trivial. The hard part is the rest of the >>> interface, which so far there is no specification for. >> >> Have you looked at docs/specs/acpi_{cpu,mem}_hotplug.txt? Writing a DT >> binding for it is trivial too. Or are we talking about two different >> things? > > Interesting. I agree that doing a DT binding for these will be trivial, > and the implementation in Linux should also be straightforward, thanks > for pointing these out. > > However, it seems that the implementation that qemu uses is incompatible > with ARM64, since GPE is not part of the ACPI hardware reduced mode. That makes it even simpler because you do not have to use SCI. -M virt currently doesn't have a GPIO controller, but it's easy to add a PL061 and specify a random GPIO pin in the DT bindings. Then you can use GPIO-signaled ACPI events in the AML, just move _Lxx methods move from \_GPE to \_SB.GPIO under the GPIO controller. Paolo