From patchwork Mon Oct 21 05:21:29 2024 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: "Kasireddy, Vivek" X-Patchwork-Id: 13843577 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 897EDD3C93E for ; Mon, 21 Oct 2024 05:46:11 +0000 (UTC) Received: from gabe.freedesktop.org (localhost [127.0.0.1]) by gabe.freedesktop.org (Postfix) with ESMTP id ACD0C10E282; Mon, 21 Oct 2024 05:46:07 +0000 (UTC) Authentication-Results: gabe.freedesktop.org; dkim=pass (2048-bit key; unprotected) header.d=intel.com header.i=@intel.com header.b="EeglAzui"; dkim-atps=neutral Received: from mgamail.intel.com (mgamail.intel.com [198.175.65.12]) by gabe.freedesktop.org (Postfix) with ESMTPS id E82A710E0A1; Mon, 21 Oct 2024 05:46:06 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=intel.com; i=@intel.com; q=dns/txt; s=Intel; t=1729489568; x=1761025568; h=from:to:cc:subject:date:message-id:in-reply-to: references:mime-version:content-transfer-encoding; bh=uV5snUpY10mY+ieUbO0PLEKGL0amDrpA0hEcIDbiYHY=; b=EeglAzuiNVpbvlwWacQ/9cxOm0lXxy+Dd1gjxa8XhGeE9LYhNqtJiHdx QkPhZkQiDz8qn9qh0Tt4MgVbbqri+shD/sfsRZM1hfQivo/Ux45Es1Oh4 HlGVLUnKxxydzVEJ++Affw2s10zMPVDcuEZnkE8YKz4fYCepqejrjbJEB Ix/SCXBRR+F5hYTWBG5QmDB/QS0iW57/shlB3OjovejEH43BBCiL5uKEG lSyoNer8N2oW2iOq+zBJoEJr5MGYWy9pzWgOKQAN9T0TGUEhXpljFK9i/ pv9C5Unt6mXjXCGwzDWBavFwtk8L+CAxko9AJMmXnqDAsvTiIHvHCMWj/ w==; X-CSE-ConnectionGUID: a5uH6u7CT/+2v/f1pOCZfg== X-CSE-MsgGUID: Q8c8ePuQQ2W8tcAbHzzlbg== X-IronPort-AV: E=McAfee;i="6700,10204,11231"; a="40345940" X-IronPort-AV: E=Sophos;i="6.11,220,1725346800"; d="scan'208";a="40345940" Received: from fmviesa001.fm.intel.com ([10.60.135.141]) by orvoesa104.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 20 Oct 2024 22:46:06 -0700 X-CSE-ConnectionGUID: UcI3brXwTsOUey9oPpOkNQ== X-CSE-MsgGUID: ER72puDBRjKLn/Fy7mxSSA== X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="6.11,220,1725346800"; d="scan'208";a="110180207" Received: from vkasired-desk2.fm.intel.com ([10.105.128.132]) by smtpauth.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 20 Oct 2024 22:46:05 -0700 From: Vivek Kasireddy To: dri-devel@lists.freedesktop.org, intel-xe@lists.freedesktop.org Cc: Vivek Kasireddy , Bjorn Helgaas , Logan Gunthorpe , linux-pci@vger.kernel.org Subject: [PATCH v2 1/5] PCI/P2PDMA: Don't enforce ACS check for functions of same device Date: Sun, 20 Oct 2024 22:21:29 -0700 Message-ID: <20241021052236.1820329-2-vivek.kasireddy@intel.com> X-Mailer: git-send-email 2.45.1 In-Reply-To: <20241021052236.1820329-1-vivek.kasireddy@intel.com> References: <20241021052236.1820329-1-vivek.kasireddy@intel.com> MIME-Version: 1.0 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" Functions of the same PCI device (such as a PF and a VF) share the same bus and have a common root port and typically, the PF provisions resources for the VF. Therefore, they can be considered compatible as far as P2P access is considered. Currently, although the distance (2) is correctly calculated for functions of the same device, an ACS check failure prevents P2P DMA access between them. Therefore, introduce a small function named pci_devs_are_p2pdma_compatible() to determine if the provider and client belong to the same device and facilitate P2P DMA between them by not enforcing the ACS check. v2: - Relax the enforcment of ACS check only for Intel GPU functions as they are P2PDMA compatible given the way the PF provisions the resources among multiple VFs. Cc: Bjorn Helgaas Cc: Logan Gunthorpe Cc: Signed-off-by: Vivek Kasireddy --- drivers/pci/p2pdma.c | 17 +++++++++++++++-- 1 file changed, 15 insertions(+), 2 deletions(-) diff --git a/drivers/pci/p2pdma.c b/drivers/pci/p2pdma.c index 4f47a13cb500..a230e661f939 100644 --- a/drivers/pci/p2pdma.c +++ b/drivers/pci/p2pdma.c @@ -535,6 +535,17 @@ static unsigned long map_types_idx(struct pci_dev *client) return (pci_domain_nr(client->bus) << 16) | pci_dev_id(client); } +static bool pci_devs_are_p2pdma_compatible(struct pci_dev *provider, + struct pci_dev *client) +{ + if (provider->vendor == PCI_VENDOR_ID_INTEL) { + if (pci_is_vga(provider) && pci_is_vga(client)) + return pci_physfn(provider) == pci_physfn(client); + } + + return false; +} + /* * Calculate the P2PDMA mapping type and distance between two PCI devices. * @@ -634,7 +645,7 @@ calc_map_type_and_dist(struct pci_dev *provider, struct pci_dev *client, *dist = dist_a + dist_b; - if (!acs_cnt) { + if (!acs_cnt || pci_devs_are_p2pdma_compatible(provider, client)) { map_type = PCI_P2PDMA_MAP_BUS_ADDR; goto done; } @@ -696,7 +707,9 @@ int pci_p2pdma_distance_many(struct pci_dev *provider, struct device **clients, return -1; for (i = 0; i < num_clients; i++) { - pci_client = find_parent_pci_dev(clients[i]); + pci_client = dev_is_pf(clients[i]) ? + pci_dev_get(to_pci_dev(clients[i])) : + find_parent_pci_dev(clients[i]); if (!pci_client) { if (verbose) dev_warn(clients[i],