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=-2.6 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS, USER_AGENT_MUTT autolearn=ham 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 89755C31E4B for ; Fri, 14 Jun 2019 13:12:56 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 529DF208CA for ; Fri, 14 Jun 2019 13:12:56 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1560517976; bh=s7zyuYWu+DaWGbyiuI6YfpVgY4YZ3vd5LpUoa4GAm24=; h=Date:From:To:Cc:Subject:References:In-Reply-To:List-ID:From; b=IE0u2+nKG/aMmfgBL2HoTbvooBlOnCBO7hqR+kEPL7QzGktU5t0U6wFtYGGJcuPge Zu6jYZlPJWPXzVpOGcUgFR0iROhyJ6eqPBf8xfYgMKrDchfBR5hlLWu80awPkMjEL5 IRp3FCme6H6GvAP8szuRIiZ4TWuZCVAKlQHEH1Kg= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727827AbfFNNMz (ORCPT ); Fri, 14 Jun 2019 09:12:55 -0400 Received: from mail.kernel.org ([198.145.29.99]:51732 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726874AbfFNNMz (ORCPT ); Fri, 14 Jun 2019 09:12:55 -0400 Received: from localhost (173-25-83-245.client.mchsi.com [173.25.83.245]) (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 EB86720850; Fri, 14 Jun 2019 13:12:54 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1560517975; bh=s7zyuYWu+DaWGbyiuI6YfpVgY4YZ3vd5LpUoa4GAm24=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=r9h4sOJw4TWqwZ6Htg6I96ppoZEAiCpUG+mrI/LkdOC+aeRusUOZ91ISOH7nOaxks v84qfGmWQ3spRQq4sQZkPS4zIH+6rZ0Hk3zwxlLwcwsq9tDqzOkq2TxyU5I/yWY0ca D194xOv9xtvOVOfuHGBKAABDHW4XhR1kSTEvX90I= Date: Fri, 14 Jun 2019 08:12:53 -0500 From: Bjorn Helgaas To: Benjamin Herrenschmidt Cc: Lorenzo Pieralisi , linux-pci , Sinan Kaya , linux-arm-kernel , Ard Biesheuvel Subject: Re: [RFC PATCH v2] arm64: acpi/pci: invoke _DSM whether to preserve firmware PCI setup Message-ID: <20190614131253.GR13533@google.com> References: <5783e36561bb77a1deb6ba67e5a9824488cc69c6.camel@kernel.crashing.org> <20190613190248.GH13533@google.com> <20190614095742.GA27188@e121166-lin.cambridge.arm.com> <906b2576756e82a54b584c3de2d8362602de07ce.camel@kernel.crashing.org> <84320a45ef9395d82bf1c5d4d2d7e6db189cbfda.camel@kernel.crashing.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <84320a45ef9395d82bf1c5d4d2d7e6db189cbfda.camel@kernel.crashing.org> User-Agent: Mutt/1.10.1 (2018-07-13) Sender: linux-pci-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-pci@vger.kernel.org On Fri, Jun 14, 2019 at 08:43:19PM +1000, Benjamin Herrenschmidt wrote: > This least to another conversation we hinted at earlier.. we should > probably have a way to do the same at least for BARs on ACPI systems so > we don't have to temporarily disable access to a device to size them. The PCI Enhanced Allocation capability provides a way to do this. I don't know how widely used it is, but it's theoretically possible.