From patchwork Sun Feb 12 16:07:45 2017 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Lukas Wunner X-Patchwork-Id: 9568435 X-Patchwork-Delegate: bhelgaas@google.com Return-Path: Received: from mail.wl.linuxfoundation.org (pdx-wl-mail.web.codeaurora.org [172.30.200.125]) by pdx-korg-patchwork.web.codeaurora.org (Postfix) with ESMTP id 6527260442 for ; Sun, 12 Feb 2017 16:08:15 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 55ED728394 for ; Sun, 12 Feb 2017 16:08:15 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id 4A84628399; Sun, 12 Feb 2017 16:08:15 +0000 (UTC) X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on pdx-wl-mail.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-6.9 required=2.0 tests=BAYES_00,RCVD_IN_DNSWL_HI autolearn=ham version=3.3.1 Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id AC7A328394 for ; Sun, 12 Feb 2017 16:08:14 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751218AbdBLQIO (ORCPT ); Sun, 12 Feb 2017 11:08:14 -0500 Received: from mailout2.hostsharing.net ([83.223.90.233]:36375 "EHLO mailout2.hostsharing.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751217AbdBLQIN (ORCPT ); Sun, 12 Feb 2017 11:08:13 -0500 Received: from h08.hostsharing.net (h08.hostsharing.net [83.223.95.28]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mailout2.hostsharing.net (Postfix) with ESMTPS id 9B8811037F6B4; Sun, 12 Feb 2017 17:08:11 +0100 (CET) Received: from localhost (3-38-90-81.adsl.cmo.de [81.90.38.3]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-SHA (128/128 bits)) (No client certificate requested) by h08.hostsharing.net (Postfix) with ESMTPSA id 5FC4F60E4ED4; Sun, 12 Feb 2017 17:08:09 +0100 (CET) X-Mailbox-Line: From fee5154ef747e34684f316a9edf1ec7f635fd0f8 Mon Sep 17 00:00:00 2001 Message-Id: In-Reply-To: References: From: Lukas Wunner Date: Sun, 12 Feb 2017 17:07:45 +0100 Subject: [PATCH v6 1/8] PCI: Recognize Thunderbolt devices To: Bjorn Helgaas Cc: Andreas Noever , linux-pci@vger.kernel.org Sender: linux-pci-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-pci@vger.kernel.org X-Virus-Scanned: ClamAV using ClamSMTP Detect on device probe whether a PCI device is part of a Thunderbolt daisy chain (i.e. it is either part of a Thunderbolt controller or part of the hierarchy below a Thunderbolt controller). Intel uses a Vendor-Specific Extended Capability (VSEC) with ID 0x1234 on devices belonging to a Thunderbolt controller. Detect presence of this VSEC on the device itself or on one of its parents and cache it in a newly added is_thunderbolt bit in struct pci_dev. The necessity arises from the following: * To power off Thunderbolt controllers on Macs when nothing is plugged in, we need to allow runtime PM on their PCIe ports in pci_bridge_d3_possible(). For this we need a way to recognize them. * Dual GPU MacBook Pros introduced 2011+ can no longer switch external DisplayPort ports between GPUs. (They're no longer just used for DP but have become combined DP/Thunderbolt ports.) The driver to switch the ports, drivers/platform/x86/apple-gmux.c, needs to detect presence of a Thunderbolt controller and, if found, keep external ports permanently switched to the discrete GPU. * If an external Thunderbolt GPU is connected to a dual GPU laptop (Mac or not), that GPU is currently registered with vga_switcheroo even though it can neither drive the laptop's panel nor be powered off by the platform. To vga_switcheroo it will appear as if two discrete GPUs are present. As a result, when the external GPU is runtime suspended, vga_switcheroo will cut power to the internal discrete GPU which may not be runtime suspended at all at this moment. The solution is to not register external GPUs with vga_switcheroo, which necessitates a way to recognize if they're part of a Thunderbolt daisy chain. Cc: Andreas Noever Cc: Tomas Winkler Cc: Amir Levy Signed-off-by: Lukas Wunner --- drivers/pci/pci.h | 2 ++ drivers/pci/probe.c | 32 ++++++++++++++++++++++++++++++++ include/linux/pci.h | 1 + 3 files changed, 35 insertions(+) diff --git a/drivers/pci/pci.h b/drivers/pci/pci.h index cb17db242f30..45c2b8144911 100644 --- a/drivers/pci/pci.h +++ b/drivers/pci/pci.h @@ -3,6 +3,8 @@ #define PCI_FIND_CAP_TTL 48 +#define PCI_VSEC_ID_INTEL_TBT 0x1234 /* Thunderbolt */ + extern const unsigned char pcie_link_speed[]; bool pcie_cap_has_lnkctl(const struct pci_dev *dev); diff --git a/drivers/pci/probe.c b/drivers/pci/probe.c index 204960e70333..2fcbc535786e 100644 --- a/drivers/pci/probe.c +++ b/drivers/pci/probe.c @@ -1208,6 +1208,35 @@ void set_pcie_hotplug_bridge(struct pci_dev *pdev) pdev->is_hotplug_bridge = 1; } +static void set_pcie_thunderbolt(struct pci_dev *dev) +{ + struct pci_dev *parent = dev; + int vsec = 0; + u32 header; + + /* Is the device part of a Thunderbolt controller? */ + while ((vsec = pci_find_next_ext_capability(dev, vsec, + PCI_EXT_CAP_ID_VNDR))) { + pci_read_config_dword(dev, vsec + PCI_VNDR_HEADER, &header); + if (dev->vendor == PCI_VENDOR_ID_INTEL && + PCI_VNDR_HEADER_ID(header) == PCI_VSEC_ID_INTEL_TBT) { + dev->is_thunderbolt = 1; + return; + } + } + + /* + * Is the device attached with Thunderbolt? Walk upwards and check for + * each encountered bridge if it's part of a Thunderbolt controller. + * Reaching the host bridge means dev is soldered to the mainboard. + */ + while ((parent = pci_upstream_bridge(parent))) + if (parent->is_thunderbolt) { + dev->is_thunderbolt = 1; + return; + } +} + /** * pci_ext_cfg_is_aliased - is ext config space just an alias of std config? * @dev: PCI device @@ -1360,6 +1389,9 @@ int pci_setup_device(struct pci_dev *dev) /* need to have dev->class ready */ dev->cfg_size = pci_cfg_space_size(dev); + /* need to have dev->cfg_size ready */ + set_pcie_thunderbolt(dev); + /* "Unknown power state" */ dev->current_state = PCI_UNKNOWN; diff --git a/include/linux/pci.h b/include/linux/pci.h index e2d1a124216a..3c775e8498f1 100644 --- a/include/linux/pci.h +++ b/include/linux/pci.h @@ -358,6 +358,7 @@ struct pci_dev { unsigned int is_virtfn:1; unsigned int reset_fn:1; unsigned int is_hotplug_bridge:1; + unsigned int is_thunderbolt:1; /* part of Thunderbolt daisy chain */ unsigned int __aer_firmware_first_valid:1; unsigned int __aer_firmware_first:1; unsigned int broken_intx_masking:1;