From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-4.0 required=3.0 tests=BAYES_00,MAILING_LIST_MULTI, SPF_HELO_NONE,SPF_PASS autolearn=no autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id CDED8C433DB for ; Thu, 21 Jan 2021 14:07:40 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 78DB3239A4 for ; Thu, 21 Jan 2021 14:07:40 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1730616AbhAUOGc (ORCPT ); Thu, 21 Jan 2021 09:06:32 -0500 Received: from mail.kernel.org ([198.145.29.99]:57508 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1728071AbhAUOGN (ORCPT ); Thu, 21 Jan 2021 09:06:13 -0500 Received: from disco-boy.misterjones.org (disco-boy.misterjones.org [51.254.78.96]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id 9445B239A4; Thu, 21 Jan 2021 14:05:29 +0000 (UTC) Received: from disco-boy.misterjones.org ([51.254.78.96] helo=www.loen.fr) by disco-boy.misterjones.org with esmtpsa (TLS1.2) tls TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256 (Exim 4.94) (envelope-from ) id 1l2aaV-009Cp4-H1; Thu, 21 Jan 2021 14:05:27 +0000 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 8bit Date: Thu, 21 Jan 2021 14:05:27 +0000 From: Marc Zyngier To: Mark Rutland Cc: Mohamed Mediouni , Arnd Bergmann , Linux ARM , Catalin Marinas , Hector Martin , linux-kernel@vger.kernel.org, Will Deacon , Stan Skowronek Subject: Re: [RFC PATCH 7/7] irqchip/apple-aic: add SMP support to the Apple AIC driver. In-Reply-To: <20210121133235.GG48431@C02TD0UTHF1T.local> References: <20210120132717.395873-1-mohamed.mediouni@caramail.com> <20210120132717.395873-8-mohamed.mediouni@caramail.com> <71e94b48857cbdd21c5d6bdadf148621@kernel.org> <20210121133235.GG48431@C02TD0UTHF1T.local> User-Agent: Roundcube Webmail/1.4.10 Message-ID: <6d4d606cd832230c159b12874d32e220@kernel.org> X-Sender: maz@kernel.org X-SA-Exim-Connect-IP: 51.254.78.96 X-SA-Exim-Rcpt-To: mark.rutland@arm.com, mohamed.mediouni@caramail.com, arnd@kernel.org, linux-arm-kernel@lists.infradead.org, catalin.marinas@arm.com, marcan@marcan.st, linux-kernel@vger.kernel.org, will@kernel.org, stan@corellium.com X-SA-Exim-Mail-From: maz@kernel.org X-SA-Exim-Scanned: No (on disco-boy.misterjones.org); SAEximRunCond expanded to false Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 2021-01-21 13:32, Mark Rutland wrote: > On Thu, Jan 21, 2021 at 01:22:37PM +0000, Marc Zyngier wrote: >> On 2021-01-21 12:50, Mohamed Mediouni wrote: >> > > On 21 Jan 2021, at 13:44, Arnd Bergmann wrote: >> > > >> > > On Wed, Jan 20, 2021 at 2:27 PM Mohamed Mediouni >> >> [...] >> >> > > > + aic.fast_ipi = of_property_read_bool(node, "fast-ipi"); >> > > >> > > Where is this property documented, and what decides which one to use? >> > It’s getting documented in the next patch set. >> > >> > This property is there to enable support for older iPhone processors >> > later on, some of which do not have fast IPI support. >> > >> > On Apple M1, fast-ipi is always on. >> >> Then please focus on a single implementation. Additional features can >> always be merged later once something is up and running. >> >> Also, there sysregs can be detected by matching the MIDR, so I don't >> think we need a DT property for that. > > Generally we do not detect IMP-DEF sysregs based on MIDR because they > won't necessarily be exposed to a VM, so I suspect that we do need DT > properties to describe that IMP-DEF sysregs are accessible, and should > not rely on the MIDR alone. Maybe that's implicit in another property, > but worth bearing in mind. Hmm. That's a good point. I think this could be keyed off the compatible property, which should accurately reflect the version of the interrupt controller. Thanks, M. -- Jazz is not dead. It just smells funny...