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 vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 281EDC433F5 for ; Mon, 2 May 2022 15:46:16 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1385984AbiEBPtn (ORCPT ); Mon, 2 May 2022 11:49:43 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:57676 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1385983AbiEBPtk (ORCPT ); Mon, 2 May 2022 11:49:40 -0400 Received: from sin.source.kernel.org (sin.source.kernel.org [IPv6:2604:1380:40e1:4800::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 0F71611166 for ; Mon, 2 May 2022 08:46:10 -0700 (PDT) Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by sin.source.kernel.org (Postfix) with ESMTPS id C0EE2CE1B33 for ; Mon, 2 May 2022 15:46:08 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 0A1D8C385A4; Mon, 2 May 2022 15:46:05 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1651506367; bh=AGY4CVS//Cd51RpEFYmg5JyDhOouWYthTY1/Nr0uweY=; h=Date:From:To:Cc:Subject:In-Reply-To:References:From; b=njbWhNN8ibMkjRTDPRZcGaDo7SemHKG5XJ6k9wLgMbYLJj8XobJmklrPDBgj38+PH bt5b/rckNEx151/bvYIMZ/vcvkDM+QNmIZ3hDKAcg/Ipc5KglkeLQjdeT+hX94VJ9a Q0ygkTieOXvdgtFzmrQ0OfUy5puN5pmBhsjbMcm2rF+QnN57u34SchHIRcl9DfNZ6u qLDRjc9509SemOj4SZ4g3NBSq+Qph9sk8clZUQybLTw/+tRov5pNdJdZBgQ7GCP+uX HXVgiMOZEWQq/eGSa/P5H4IRwanN77L33P920KgfXuiUkUpVenFhZ2zogJ2jXI008I hLVuLc+nr5BVQ== Date: Mon, 2 May 2022 17:45:59 +0200 From: Marek =?UTF-8?B?QmVow7pu?= To: Marc Zyngier Cc: linux-kernel@vger.kernel.org, Thomas Gleixner , pali@kernel.org Subject: Re: irqdomain API: how to set affinity of parent irq of chained irqs? Message-ID: <20220502174559.78f5cbc0@dellmb> In-Reply-To: <87mtg0i8m8.wl-maz@kernel.org> References: <20220502102137.764606ee@thinkpad> <87mtg0i8m8.wl-maz@kernel.org> X-Mailer: Claws Mail 3.18.0 (GTK+ 2.24.33; x86_64-pc-linux-gnu) MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: quoted-printable Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Mon, 02 May 2022 10:31:11 +0100 Marc Zyngier wrote: > On Mon, 02 May 2022 09:21:37 +0100, > Marek Beh=C3=BAn wrote: > >=20 > > Dear Marc, Thomas, > >=20 > > we have encountered the following problem that can hopefully be put > > some light onto: What is the intended way to set affinity (and possibly > > other irq attributes) of parent IRQ of chained IRQs, when using the > > irqdomain API? =20 >=20 > Simples: you can't. What sense does it make to change the affinity of > the parent interrupt, given that its fate is tied to *all* of the > other interrupts that are muxed to it? Dear Marc, thank you for your answer. Still: What about when we want to set the same affinity for all the chained interrupts? Example: on Armada 385 there are 4 PCIe controllers. Each controller has one interrupt from which we trigger chained interrupts. We would like to configure each controller to trigger interrupt (and thus all chained interrupts in the domain) on different CPU core. Moreover we would really like to do this in runtime, through sysfs, depending on for example whether there are cards plugged in the PCIe ports. Maybe there should be some mechanism to allow to change affinity for whole irqdomain, or something? Marek