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 gabe.freedesktop.org (gabe.freedesktop.org [131.252.210.177]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id F26EEC982DA for ; Sun, 20 Sep 2026 11:34:28 +0000 (UTC) Received: from gabe.freedesktop.org (localhost [127.0.0.1]) by gabe.freedesktop.org (Postfix) with ESMTP id 49D6710E270; Sun, 20 Sep 2026 11:34:28 +0000 (UTC) Authentication-Results: gabe.freedesktop.org; dkim=pass (2048-bit key; unprotected) header.d=kernel.org header.i=@kernel.org header.b="VFMSaX2Q"; dkim-atps=neutral Received: from tor.source.kernel.org (tor.source.kernel.org [172.105.4.254]) by gabe.freedesktop.org (Postfix) with ESMTPS id 9FDA710E270 for ; Sun, 20 Sep 2026 11:34:26 +0000 (UTC) Received: from smtp.kernel.org (quasi.space.kernel.org [100.103.45.18]) by tor.source.kernel.org (Postfix) with ESMTP id 91A7C601FD; Sun, 20 Sep 2026 11:34:25 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id B2F8B1F000FF; Sun, 20 Sep 2026 11:34:24 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel.org; s=k20260515; t=1789904065; bh=o19pe/ZOLyrZCZ3xyrwO1dORVM3jdvZ7EUMrrqzx/sc=; h=Date:From:To:Cc:Subject:References:In-Reply-To; b=VFMSaX2QgFUMmyoiYEHSjLc/YfwGFUF3rSLLzSb2RiXDkOR7tmvx4AY/6QchwV3wu xeWUQxUhhztHSVXpmcqxd4iqduYww8bbeCtiHJfpMz1pfMiQUuaj2PbxBLbmtc2AVs RW4amWSOxw0/mXmmK9XiN4M56nT+PJrStacNKmoGeJhzwjU/TClMc1A93FPpvV1qj0 4kvnM+JB1F/VN7YizD46bisQXK96UBmamDCtbu9NznIAdQIistrUXjdXzPIOeaoz44 Loan/RBqqvKvQOhKbpql7J+qkl05ra9OO2t3kzyrMr2XjYrj2CZWkqgAm0EWLqgRjI 3aMGDeyQ5tflA== Date: Sun, 20 Sep 2026 14:34:20 +0300 From: Leon Romanovsky To: Logan Gunthorpe Cc: Bjorn Helgaas , Chaitanya Kulkarni , Greg Kroah-Hartman , Jens Axboe , Alex Williamson , Ankit Agrawal , Jason Gunthorpe , Jonathan Corbet , Shuah Khan , "Joerg Roedel (AMD)" , Will Deacon , Robin Murphy , Randy Dunlap , Sumit Semwal , Christian =?iso-8859-1?Q?K=F6nig?= , linux-pci@vger.kernel.org, linux-kernel@vger.kernel.org, linux-doc@vger.kernel.org, iommu@lists.linux.dev, Tushar Dave , linux-media@vger.kernel.org, dri-devel@lists.freedesktop.org, linaro-mm-sig@lists.linaro.org, linux-rdma@vger.kernel.org, kvm@vger.kernel.org Subject: Re: [PATCH v6 03/18] PCI/P2PDMA: Derive routing from directional ACS controls Message-ID: <20260920113420.GA563127@unreal> References: <20260914-fix-p2p-acs-v4-0-v6-0-5ef07ec9ef06@nvidia.com> <20260914-fix-p2p-acs-v4-0-v6-3-5ef07ec9ef06@nvidia.com> <19bee27e-17d7-4b67-b796-ca5bb44e8de7@deltatee.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <19bee27e-17d7-4b67-b796-ca5bb44e8de7@deltatee.com> X-BeenThere: dri-devel@lists.freedesktop.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: Direct Rendering Infrastructure - Development List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: dri-devel-bounces@lists.freedesktop.org Sender: "dri-devel" On Fri, Sep 18, 2026 at 01:39:55PM -0600, Logan Gunthorpe wrote: > > > On 2026-09-14 05:22, Leon Romanovsky wrote: > > From: Leon Romanovsky > > > > pci_bridge_has_acs_redir() treats Request and Completion Redirect as > > interchangeable. On asymmetric fabrics, a control for only the reverse TLP > > direction can unnecessarily force P2PDMA through the host bridge. > > > > Evaluate Request Redirect for client Requests and Completion Redirect for > > provider read Completions. Continue treating enabled Egress Control > > conservatively as a Request redirect. > > > > Fixes: 52916982af48 ("PCI/P2PDMA: Support peer-to-peer memory") > > Signed-off-by: Leon Romanovsky > > Core patch seems fine, minus one minor point below: > > Reviewed-by: Logan Gunthorpe > > > @@ -1132,10 +1173,10 @@ EXPORT_SYMBOL_GPL(pci_p2pmem_publish); > > /** > > * pci_p2pdma_map_type - Determine the mapping type for P2PDMA transfers > > * @provider: P2PDMA provider structure > > - * @dev: Target device for the transfer > > + * @dev: Client device that initiates the transfer > > * > > * Determines how peer-to-peer DMA transfers should be mapped between > > - * the provider and the target device. The mapping type indicates whether > > + * the provider and the client device. The mapping type indicates whether > > * the transfer can be done directly through PCI switches or must go > > * through the host bridge. > > */ > > > > This hunk does not seem like it belongs in this patch. This is the first patch that distinguishes between client and provider and starts using that terminology instead of target/initiator. Therefore, the change belongs here. Thanks