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=-5.6 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,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 A5D9AC11D8A for ; Wed, 19 Feb 2020 22:30:44 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 4312324699 for ; Wed, 19 Feb 2020 22:24:58 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1582151098; bh=wZL3OOt1mgp9hbAl9bojkNL3ZJ0+D9P0cl+P8V4kYOs=; h=Date:From:To:Cc:Subject:References:In-Reply-To:List-ID:From; b=Tp/uPClB44FfqTjKqLnM+IStvLkywdOnSlza1vTzFrORrLDWBuvZkv9a40a9q7fr2 rJHqRXb08fEYAlhyd+mOxycsEpnlpSvRK5k+QKrB7m0nHO2ERWEo8I4NtscgkxBFEf YmEL1rvog7IlWIo9m1D/ScYseXB2NZcTLvavv6Gk= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727462AbgBSWY5 (ORCPT ); Wed, 19 Feb 2020 17:24:57 -0500 Received: from mail-oi1-f193.google.com ([209.85.167.193]:34831 "EHLO mail-oi1-f193.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727163AbgBSWY5 (ORCPT ); Wed, 19 Feb 2020 17:24:57 -0500 Received: by mail-oi1-f193.google.com with SMTP id b18so25521148oie.2; Wed, 19 Feb 2020 14:24:57 -0800 (PST) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:date:from:to:cc:subject:message-id:references :mime-version:content-disposition:in-reply-to:user-agent; bh=bw/arhxO0zD6uxPv9B55JT/z9CSekm6k6Bmp/kVtLV0=; b=iDoyGV5c0sHKnm8fR8KkHHXF/ntWO0w46zg5ISA1UjqFbYZT6PWEJgNscnK/WbzFiq zST2+piKM7q4lOxSJE3idurDkXnWN9cSm6HbTejthJM8QihAnSXj8sXAo7xbKMTtaAS7 R+WoTJmlNxUJkgnSnwOknoV1cqtrkw7YI9ZMijGBZoRy9hvljRb3nHsjSnn0202Hxko5 ctpdzYwDrwk5IAm+qS6+AOz7vbKP3Y95XtDb/Qv/Y2j1gvtcBF4uxDIfF+BjDYotZnno 20hfTkJf79AF5oeNR9v6EGFKZ/8u7aOzMtdKfUJeOVRhd5US+KM0S1fes2AIirl+AuPS hjwQ== X-Gm-Message-State: APjAAAUGzG6jwCLUc/rfUKD8lpIHVFw6wRIecqwf7YvXqQxbHcZIFltT MvGzhud4J5MSdT4SGnsLUg== X-Google-Smtp-Source: APXvYqzZzuIwDzmzfqhTKUe49az+Etwqyco/nG1nDw+t4D7VEkxMrWlgNAsahLPneOunxOSWnXEiHQ== X-Received: by 2002:aca:d903:: with SMTP id q3mr6124909oig.12.1582151096719; Wed, 19 Feb 2020 14:24:56 -0800 (PST) Received: from rob-hp-laptop (24-155-109-49.dyn.grandenetworks.net. [24.155.109.49]) by smtp.gmail.com with ESMTPSA id l80sm428436oib.37.2020.02.19.14.24.55 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Wed, 19 Feb 2020 14:24:56 -0800 (PST) Received: (nullmailer pid 16262 invoked by uid 1000); Wed, 19 Feb 2020 22:24:54 -0000 Date: Wed, 19 Feb 2020 16:24:54 -0600 From: Rob Herring To: Jean-Philippe Brucker Cc: bhelgaas@google.com, will@kernel.org, robh+dt@kernel.org, lorenzo.pieralisi@arm.com, joro@8bytes.org, baolu.lu@linux.intel.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, corbet@lwn.net, mark.rutland@arm.com, liviu.dudau@arm.com, sudeep.holla@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 01/11] dt-bindings: PCI: generic: Add ats-supported property Message-ID: <20200219222454.GA16221@bogus> References: <20200213165049.508908-1-jean-philippe@linaro.org> <20200213165049.508908-2-jean-philippe@linaro.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20200213165049.508908-2-jean-philippe@linaro.org> User-Agent: Mutt/1.10.1 (2018-07-13) Sender: devicetree-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: devicetree@vger.kernel.org On Thu, 13 Feb 2020 17:50:39 +0100, Jean-Philippe Brucker wrote: > Add a way for firmware to tell the OS that ATS is supported by the PCI > root complex. An endpoint with ATS enabled may send Translation Requests > and Translated Memory Requests, which look just like Normal Memory > Requests with a non-zero AT field. So a root controller that ignores the > AT field may simply forward the request to the IOMMU as a Normal Memory > Request, which could end badly. In any case, the endpoint will be > unusable. > > The ats-supported property allows the OS to only enable ATS in endpoints > if the root controller can handle ATS requests. Only add the property to > pcie-host-ecam-generic for the moment. For non-generic root controllers, > availability of ATS can be inferred from the compatible string. > > Signed-off-by: Jean-Philippe Brucker > --- > Documentation/devicetree/bindings/pci/host-generic-pci.yaml | 6 ++++++ > 1 file changed, 6 insertions(+) > Reviewed-by: Rob Herring