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 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id A012CC433EF for ; Tue, 16 Nov 2021 18:12:43 +0000 (UTC) Received: from lists.ozlabs.org (lists.ozlabs.org [112.213.38.117]) (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 C606161546 for ; Tue, 16 Nov 2021 18:12:42 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.4.1 mail.kernel.org C606161546 Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=kaod.org Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=lists.ozlabs.org Received: from boromir.ozlabs.org (localhost [IPv6:::1]) by lists.ozlabs.org (Postfix) with ESMTP id 4HtvL06chfz3c4c for ; Wed, 17 Nov 2021 05:12:40 +1100 (AEDT) Authentication-Results: lists.ozlabs.org; spf=pass (sender SPF authorized) smtp.mailfrom=kaod.org (client-ip=46.105.37.156; helo=8.mo552.mail-out.ovh.net; envelope-from=clg@kaod.org; receiver=) X-Greylist: delayed 12168 seconds by postgrey-1.36 at boromir; Wed, 17 Nov 2021 05:12:11 AEDT Received: from 8.mo552.mail-out.ovh.net (8.mo552.mail-out.ovh.net [46.105.37.156]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (2048 bits) server-digest SHA256) (No client certificate requested) by lists.ozlabs.org (Postfix) with ESMTPS id 4HtvKR3CQJz2yP0 for ; Wed, 17 Nov 2021 05:12:09 +1100 (AEDT) Received: from mxplan5.mail.ovh.net (unknown [10.109.138.7]) by mo552.mail-out.ovh.net (Postfix) with ESMTPS id 1704921485; Tue, 16 Nov 2021 17:56:03 +0000 (UTC) Received: from kaod.org (37.59.142.97) by DAG4EX1.mxp5.local (172.16.2.31) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256) id 15.1.2308.20; Tue, 16 Nov 2021 18:56:02 +0100 Authentication-Results: garm.ovh; auth=pass (GARM-97G002d58e9868-7e9e-4c60-b756-0af7795efd8f, BFAEB7FE3C4E2C4D96001007C3BA12B7689A693E) smtp.auth=clg@kaod.org X-OVh-ClientIp: 129.41.46.1 Message-ID: Date: Tue, 16 Nov 2021 18:56:01 +0100 MIME-Version: 1.0 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:91.0) Gecko/20100101 Thunderbird/91.2.0 Subject: Re: [PATCH] powerpc/xive: Change IRQ domain to a tree domain Content-Language: en-US To: Marc Zyngier References: <20211116134022.420412-1-clg@kaod.org> <874k8c82cn.wl-maz@kernel.org> From: =?UTF-8?Q?C=c3=a9dric_Le_Goater?= In-Reply-To: <874k8c82cn.wl-maz@kernel.org> Content-Type: text/plain; charset="UTF-8"; format=flowed Content-Transfer-Encoding: 8bit X-Originating-IP: [37.59.142.97] X-ClientProxiedBy: DAG9EX2.mxp5.local (172.16.2.82) To DAG4EX1.mxp5.local (172.16.2.31) X-Ovh-Tracer-GUID: 0445f3c0-5ed6-4ebc-a344-ab6638c91627 X-Ovh-Tracer-Id: 17344206590952442788 X-VR-SPAMSTATE: OK X-VR-SPAMSCORE: -100 X-VR-SPAMCAUSE: gggruggvucftvghtrhhoucdtuddrgedvuddrfedvgddutdegucetufdoteggodetrfdotffvucfrrhhofhhilhgvmecuqfggjfdpvefjgfevmfevgfenuceurghilhhouhhtmecuhedttdenucesvcftvggtihhpihgvnhhtshculddquddttddmnecujfgurhepkfffgggfuffvfhfhjggtgfhisehtkeertddtfeejnecuhfhrohhmpeevrogurhhitggpnfgvpgfiohgrthgvrhcuoegtlhhgsehkrghougdrohhrgheqnecuggftrfgrthhtvghrnhepieegvdffkeegfeetuddttddtveduiefhgeduffekiedtkeekteekhfffleevleelnecukfhppedtrddtrddtrddtpdefjedrheelrddugedvrdeljeenucevlhhushhtvghrufhiiigvpedtnecurfgrrhgrmhepmhhouggvpehsmhhtphhouhhtpdhhvghlohepmhigphhlrghnhedrmhgrihhlrdhovhhhrdhnvghtpdhinhgvtheptddrtddrtddrtddpmhgrihhlfhhrohhmpegtlhhgsehkrghougdrohhrghdprhgtphhtthhopehgrhhouhhgsehkrghougdrohhrgh X-BeenThere: linuxppc-dev@lists.ozlabs.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: Linux on PowerPC Developers Mail List List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: linuxppc-dev@lists.ozlabs.org, Greg Kurz , stable@vger.kernel.org Errors-To: linuxppc-dev-bounces+linuxppc-dev=archiver.kernel.org@lists.ozlabs.org Sender: "Linuxppc-dev" On 11/16/21 17:58, Marc Zyngier wrote: > On Tue, 16 Nov 2021 13:40:22 +0000, > Cédric Le Goater wrote: >> >> Commit 4f86a06e2d6e ("irqdomain: Make normal and nomap irqdomains >> exclusive") introduced an IRQ_DOMAIN_FLAG_NO_MAP flag to isolate the >> 'nomap' domains still in use under the powerpc arch. With this new >> flag, the revmap_tree of the IRQ domain is not used anymore. This >> change broke the support of shared LSIs [1] in the XIVE driver because >> it was relying on a lookup in the revmap_tree to query previously >> mapped interrupts. > > Just a lookup? Surely there is more to it, no? nope. The HW IRQ for the INTx is defined in the DT. It is caught by of_irq_parse_and_map_pci() which simply adds an extra mapping on the same INTx since the previous one is not found. Using an INTx is quite rare now days and a shared one is even more uncommon I guess, I could only reproduced on the baremetal platform with the QEMU PowerNV machine using the same virtio devices. Thanks, C. > >> Linux now creates two distinct IRQ mappings on the >> same HW IRQ which can lead to unexpected behavior in the drivers. >> >> The XIVE IRQ domain is not a direct mapping domain and its HW IRQ >> interrupt number space is rather large : 1M/socket on POWER9 and >> POWER10, change the XIVE driver to use a 'tree' domain type instead. >> >> [1] For instance, a linux KVM guest with virtio-rng and virtio-balloon >> devices. >> >> Cc: Marc Zyngier >> Cc: stable@vger.kernel.org # v5.14+ >> Fixes: 4f86a06e2d6e ("irqdomain: Make normal and nomap irqdomains exclusive") >> Signed-off-by: Cédric Le Goater >> --- >> >> Marc, >> >> The Fixes tag is there because the patch in question revealed that >> something was broken in XIVE. genirq is not in cause. However, I >> don't know for PS3 and Cell. May be less critical for now. > > Depends if they expect something that a no-map domain cannot provide.> >> >> arch/powerpc/sysdev/xive/common.c | 3 +-- >> arch/powerpc/sysdev/xive/Kconfig | 1 - >> 2 files changed, 1 insertion(+), 3 deletions(-) >> >> diff --git a/arch/powerpc/sysdev/xive/common.c b/arch/powerpc/sysdev/xive/common.c >> index fed6fd16c8f4..9d0f0fe25598 100644 >> --- a/arch/powerpc/sysdev/xive/common.c >> +++ b/arch/powerpc/sysdev/xive/common.c >> @@ -1536,8 +1536,7 @@ static const struct irq_domain_ops xive_irq_domain_ops = { >> >> static void __init xive_init_host(struct device_node *np) >> { >> - xive_irq_domain = irq_domain_add_nomap(np, XIVE_MAX_IRQ, >> - &xive_irq_domain_ops, NULL); >> + xive_irq_domain = irq_domain_add_tree(np, &xive_irq_domain_ops, NULL); >> if (WARN_ON(xive_irq_domain == NULL)) >> return; >> irq_set_default_host(xive_irq_domain); >> diff --git a/arch/powerpc/sysdev/xive/Kconfig b/arch/powerpc/sysdev/xive/Kconfig >> index 97796c6b63f0..785c292d104b 100644 >> --- a/arch/powerpc/sysdev/xive/Kconfig >> +++ b/arch/powerpc/sysdev/xive/Kconfig >> @@ -3,7 +3,6 @@ config PPC_XIVE >> bool >> select PPC_SMP_MUXED_IPI >> select HARDIRQS_SW_RESEND >> - select IRQ_DOMAIN_NOMAP >> >> config PPC_XIVE_NATIVE >> bool > > As long as this works, I'm happy with one less no-map user. > > Acked-by: Marc Zyngier > > M. >