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=-4.7 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS, URIBL_BLOCKED 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 C1A13C4338F for ; Thu, 5 Aug 2021 08:37:21 +0000 (UTC) Received: from bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id 899DF61078 for ; Thu, 5 Aug 2021 08:37:21 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.4.1 mail.kernel.org 899DF61078 Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=kernel.org Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=lists.infradead.org DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20210309; h=Sender: Content-Transfer-Encoding:Content-Type:List-Subscribe:List-Help:List-Post: List-Archive:List-Unsubscribe:List-Id:MIME-Version:References:In-Reply-To: Subject:Cc:To:From:Message-ID:Date:Reply-To:Content-ID:Content-Description: Resent-Date:Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID: List-Owner; bh=8fbN1WR9xHpR9MpZRZ9T0mEBQP9kViX+7vEoLM2JGDE=; b=nXs2Dhtg3q7YGH 6YM6iF+dJ8fYXgkBeN/qj5veAUNEmhRK2mx626y/mLd3BKcCemao571FWekSVKiTdukzItaoBHWlZ +CIhJBpaBPu7Mog9yH/wW5KikqCChHA0ANNmStNOltJA4iAvQWZP7OewGVScS7EgaB9N7aHMcI0NI u7tLxdvZXBgC8TV7o62REPXGDY3mDPG+NflRoZ9GC7f8WPfIbXqtCOxx28+igC7jMDBkN0wnL1Ayz y9gf0A9GN8qJUdSosblWNpebScRl+DQt4C0SS8yossmVBTkPAN/jX/Apwqaob7y2SeAf9CeiWUdcH DN3LYvoUzGRtw1k1y2BQ==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.94.2 #2 (Red Hat Linux)) id 1mBYqa-008gGh-7N; Thu, 05 Aug 2021 08:35:24 +0000 Received: from mail.kernel.org ([198.145.29.99]) by bombadil.infradead.org with esmtps (Exim 4.94.2 #2 (Red Hat Linux)) id 1mBYqW-008gG5-Dk for linux-arm-kernel@lists.infradead.org; Thu, 05 Aug 2021 08:35:21 +0000 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 0642060F43; Thu, 5 Aug 2021 08:35:20 +0000 (UTC) Received: from sofa.misterjones.org ([185.219.108.64] helo=why.misterjones.org) by disco-boy.misterjones.org with esmtpsa (TLS1.3) tls TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384 (Exim 4.94.2) (envelope-from ) id 1mBYqU-0035ZU-0u; Thu, 05 Aug 2021 09:35:18 +0100 Date: Thu, 05 Aug 2021 09:35:17 +0100 Message-ID: <87wnp0b86y.wl-maz@kernel.org> From: Marc Zyngier To: Sunil Muthuswamy Cc: Robin Murphy , Thomas Gleixner , "linux-kernel@vger.kernel.org" , "linux-arm-kernel@lists.infradead.org" , "catalin.marinas@arm.com" , "will@kernel.org" , Michael Kelley , Boqun Feng , KY Srinivasan , Arnd Bergmann Subject: Re: [EXTERNAL] Re: [RFC 1/1] irqchip/gic-v3-its: Add irq domain and chip for Direct LPI without ITS In-Reply-To: References: <87a6mt2jke.wl-maz@kernel.org> <87tuka24kj.wl-maz@kernel.org> <87r1f9wooc.wl-maz@kernel.org> User-Agent: Wanderlust/2.15.9 (Almost Unreal) SEMI-EPG/1.14.7 (Harue) FLIM-LB/1.14.9 (=?UTF-8?B?R29qxY0=?=) APEL-LB/10.8 EasyPG/1.0.0 Emacs/27.1 (x86_64-pc-linux-gnu) MULE/6.0 (HANACHIRUSATO) MIME-Version: 1.0 (generated by SEMI-EPG 1.14.7 - "Harue") X-SA-Exim-Connect-IP: 185.219.108.64 X-SA-Exim-Rcpt-To: sunilmut@microsoft.com, robin.murphy@arm.com, tglx@linutronix.de, linux-kernel@vger.kernel.org, linux-arm-kernel@lists.infradead.org, catalin.marinas@arm.com, will@kernel.org, mikelley@microsoft.com, Boqun.Feng@microsoft.com, kys@microsoft.com, arnd@arndb.de X-SA-Exim-Mail-From: maz@kernel.org X-SA-Exim-Scanned: No (on disco-boy.misterjones.org); SAEximRunCond expanded to false X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20210805_013520_528884_74395D4A X-CRM114-Status: GOOD ( 22.53 ) X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.34 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+linux-arm-kernel=archiver.kernel.org@lists.infradead.org On Wed, 04 Aug 2021 21:10:43 +0100, Sunil Muthuswamy wrote: > > Thanks Marc and Robin for clarifying. I see and understand the point > about having explicit MSI mappings in the firmware specification for > Direct LPIs for generic hardware support. > > Hey Mark I assume this is for me? > would you be willing to consider a scoped down implementation of GIC > Direct LPI with just an IRQ chip implementation and no Direct LPI > PCI-MSI IRQ chip. Could you please clarify? If you are not implementing MSIs, how can a device signal LPIs? At the end of the day, something has to write into the RD, and it isn't going to happen by sheer magic. > This will allow a MSI provider (such as Hyper-V vPCI) to provide a > PCI-MSI IRQ chip on top of the Direct LPI IRQ chip and enable > PCI-MSI scenarios, and avoid building in assumptions in other cases > (like PCI) where firmware specification is not available. I really don't get what you are suggesting. Could you please describe what you have in mind? M. -- Without deviation from the norm, progress is not possible. _______________________________________________ linux-arm-kernel mailing list linux-arm-kernel@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-arm-kernel