From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753422AbbIRK0m (ORCPT ); Fri, 18 Sep 2015 06:26:42 -0400 Received: from mail-wi0-f182.google.com ([209.85.212.182]:34149 "EHLO mail-wi0-f182.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753068AbbIRK0k (ORCPT ); Fri, 18 Sep 2015 06:26:40 -0400 Subject: Re: [RFC PATCH v2 0/7] Pseudo-NMI for arm64 using ICC_PMR_EL1 (GICv3) To: Jon Masters References: <1442237181-17064-1-git-send-email-daniel.thompson@linaro.org> <32CDD1A8-EF10-4F6B-86B6-64981874361A@jonmasters.org> Cc: "linux-arm-kernel@lists.infradead.org" , "linaro-kernel@lists.linaro.org" , "patches@linaro.org" , Marc Zyngier , Catalin Marinas , "linux-kernel@vger.kernel.org" , Dave Martin , Andrew Thoelke From: Daniel Thompson Message-ID: <55FBF42B.2090806@linaro.org> Date: Fri, 18 Sep 2015 12:23:23 +0100 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:38.0) Gecko/20100101 Thunderbird/38.2.0 MIME-Version: 1.0 In-Reply-To: <32CDD1A8-EF10-4F6B-86B6-64981874361A@jonmasters.org> Content-Type: text/plain; charset=windows-1252; format=flowed Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 18/09/15 06:11, Jon Masters wrote: >> On Sep 14, 2015, at 06:26, Daniel Thompson wrote: >> This patchset provides a pseudo-NMI for arm64 kernels by reimplementing >> the irqflags macros to modify the GIC PMR (the priority mask register is >> accessible as a system register on GICv3 and later) rather than the >> PSR. The patchset includes an implementation of >> arch_trigger_all_cpu_backtrace() for arm64 allowing the new code to be >> exercised. > > I think there is a need to connect a few dots on this next week > during Connect. Some other conversations have discussed alternative > implementations elsewhere. I will assist. Fine by me. I'd be very happy to talk about alternative approaches. In the past I've had long conversations about trapping to ARM TF as a means to simulate NMI. I haven't written any code to move in this direction but I still think of it as being the future-areas-of-interest pile. That said, whenever I search for (what I think are) sensible keywords for this subject I generally only find my own work! I may be selecting a rather blinkered set of keywords when I search but nevertheless it does mean I will probably have to rely on you to make introductions! Daniel. From mboxrd@z Thu Jan 1 00:00:00 1970 From: daniel.thompson@linaro.org (Daniel Thompson) Date: Fri, 18 Sep 2015 12:23:23 +0100 Subject: [RFC PATCH v2 0/7] Pseudo-NMI for arm64 using ICC_PMR_EL1 (GICv3) In-Reply-To: <32CDD1A8-EF10-4F6B-86B6-64981874361A@jonmasters.org> References: <1442237181-17064-1-git-send-email-daniel.thompson@linaro.org> <32CDD1A8-EF10-4F6B-86B6-64981874361A@jonmasters.org> Message-ID: <55FBF42B.2090806@linaro.org> To: linux-arm-kernel@lists.infradead.org List-Id: linux-arm-kernel.lists.infradead.org On 18/09/15 06:11, Jon Masters wrote: >> On Sep 14, 2015, at 06:26, Daniel Thompson wrote: >> This patchset provides a pseudo-NMI for arm64 kernels by reimplementing >> the irqflags macros to modify the GIC PMR (the priority mask register is >> accessible as a system register on GICv3 and later) rather than the >> PSR. The patchset includes an implementation of >> arch_trigger_all_cpu_backtrace() for arm64 allowing the new code to be >> exercised. > > I think there is a need to connect a few dots on this next week > during Connect. Some other conversations have discussed alternative > implementations elsewhere. I will assist. Fine by me. I'd be very happy to talk about alternative approaches. In the past I've had long conversations about trapping to ARM TF as a means to simulate NMI. I haven't written any code to move in this direction but I still think of it as being the future-areas-of-interest pile. That said, whenever I search for (what I think are) sensible keywords for this subject I generally only find my own work! I may be selecting a rather blinkered set of keywords when I search but nevertheless it does mean I will probably have to rely on you to make introductions! Daniel.