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=-8.6 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,FAKE_REPLY_C,INCLUDES_PATCH,MAILING_LIST_MULTI, SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS,USER_AGENT_SANE_1 autolearn=unavailable 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 77A77C1975A for ; Thu, 12 Mar 2020 21:02:01 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 500C4206CD for ; Thu, 12 Mar 2020 21:02:01 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1584046921; bh=/e9LLeJ5dACgdtAw3HHaj6wtWKVc0kxLbLGS8/Q25qw=; h=Date:From:To:Cc:Subject:In-Reply-To:List-ID:From; b=Y60zwNPZbmcUkOFYlKJTkjLWFOylya/fq9zoGtdUS438WfodZIxeBajAnYbelK4/3 BeoCJa+lGqSbB8jpz1DxJnJxFt5VRd5svk/SzXZWEHQsuaf/y7KjuFaEX8v0Wp1oqo IiV7wv4BBlDh9BQh5vO3OJy1vOhCC8/YiXO7xYOE= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726892AbgCLVCA (ORCPT ); Thu, 12 Mar 2020 17:02:00 -0400 Received: from mail.kernel.org ([198.145.29.99]:48128 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726571AbgCLVCA (ORCPT ); Thu, 12 Mar 2020 17:02:00 -0400 Received: from localhost (mobile-166-175-186-165.mycingular.net [166.175.186.165]) (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 158B320674; Thu, 12 Mar 2020 21:01:59 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1584046919; bh=/e9LLeJ5dACgdtAw3HHaj6wtWKVc0kxLbLGS8/Q25qw=; h=Date:From:To:Cc:Subject:In-Reply-To:From; b=EdwLzcJvSjpI3Th7mp7lKFatB+Yn47XEfNY+YgjNT3ENbyGBE0r12eGlfupHp5IcO TT8zsQMtI4TjFzhyJjyXL5LlLSL1a5GlHXoya30uKdsCtQVAkqrDLP566944IgMvPi nkoB08xDowbPCi+qj0dPDSH9lPbxsLbhzikPdbJs= Date: Thu, 12 Mar 2020 16:01:57 -0500 From: Bjorn Helgaas To: Jean-Philippe Brucker Cc: will@kernel.org, robh+dt@kernel.org, joro@8bytes.org, baolu.lu@linux.intel.com, sudeep.holla@arm.com, linux-doc@vger.kernel.org, linux-pci@vger.kernel.org, linux-arm-kernel@lists.infradead.org, devicetree@vger.kernel.org, linux-acpi@vger.kernel.org, iommu@lists.linux-foundation.org, lorenzo.pieralisi@arm.com, corbet@lwn.net, mark.rutland@arm.com, liviu.dudau@arm.com, guohanjun@huawei.com, rjw@rjwysocki.net, lenb@kernel.org, robin.murphy@arm.com, dwmw2@infradead.org, amurray@thegoodpenguin.co.uk, frowand.list@gmail.com Subject: Re: [PATCH v2 05/11] PCI/ATS: Gather checks into pci_ats_supported() Message-ID: <20200312210157.GA180471@google.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20200311124506.208376-6-jean-philippe@linaro.org> User-Agent: Mutt/1.12.2 (2019-09-21) Sender: linux-pci-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-pci@vger.kernel.org On Wed, Mar 11, 2020 at 01:45:00PM +0100, Jean-Philippe Brucker wrote: > IOMMU drivers need to perform several tests when checking if a device > supports ATS. Move them all into a new function that returns true when > a device and its host bridge support ATS. > > Since pci_enable_ats() now calls pci_ats_supported(), the following > new checks are now common: > * whether a device is trusted. Devices plugged into external-facing > ports such as thunderbolt are untrusted. > * whether the host bridge supports ATS, which defaults to true unless > the firmware description states that ATS isn't supported by the host > bridge. > > Signed-off-by: Jean-Philippe Brucker Acked-by: Bjorn Helgaas > --- > drivers/pci/ats.c | 30 +++++++++++++++++++++++++++++- > include/linux/pci-ats.h | 3 +++ > 2 files changed, 32 insertions(+), 1 deletion(-) > > diff --git a/drivers/pci/ats.c b/drivers/pci/ats.c > index 390e92f2d8d1..bbfd0d42b8b9 100644 > --- a/drivers/pci/ats.c > +++ b/drivers/pci/ats.c > @@ -30,6 +30,34 @@ void pci_ats_init(struct pci_dev *dev) > dev->ats_cap = pos; > } > > +/** > + * pci_ats_supported - check if the device can use ATS > + * @dev: the PCI device > + * > + * Returns true if the device supports ATS and is allowed to use it, false > + * otherwise. > + */ > +bool pci_ats_supported(struct pci_dev *dev) > +{ > + struct pci_host_bridge *bridge; > + > + if (!dev->ats_cap) > + return false; > + > + if (dev->untrusted) > + return false; > + > + bridge = pci_find_host_bridge(dev->bus); > + if (!bridge) > + return false; > + > + if (!bridge->ats_supported) > + return false; > + > + return true; I assume this is the same as return bridge->ats_supported; Only "assuming" because I'm not a C language lawyer, but I assume it does the obvious conversion from unsigned:1 to bool. > +}