From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1756917AbcLQOkK (ORCPT ); Sat, 17 Dec 2016 09:40:10 -0500 Received: from mailout1.hostsharing.net ([83.223.95.204]:57745 "EHLO mailout1.hostsharing.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1756653AbcLQOkI (ORCPT ); Sat, 17 Dec 2016 09:40:08 -0500 X-Mailbox-Line: From 7a82ceafe7d9af7609408c042bb9bf55af5a1a86 Mon Sep 17 00:00:00 2001 Message-Id: <7a82ceafe7d9af7609408c042bb9bf55af5a1a86.1481926599.git.lukas@wunner.de> In-Reply-To: References: From: Lukas Wunner Date: Sat, 17 Dec 2016 15:39:39 +0100 Subject: [PATCH v3 1/7] PCI: Recognize Thunderbolt devices To: Greg Kroah-Hartman , linux-kernel@vger.kernel.org Cc: Andreas Noever , linux-pci@vger.kernel.org, linux-pm@vger.kernel.org, Tomas Winkler , Amir Levy , Bjorn Helgaas Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org We're about to allow runtime PM on Thunderbolt ports in pci_bridge_d3_possible() and unblock runtime PM for Thunderbolt host hotplug ports in pci_dev_check_d3cold(). In both cases we need to uniquely identify if a PCI device belongs to a Thunderbolt controller. We also have the need to detect presence of a Thunderbolt controller in drivers/platform/x86/apple-gmux.c because dual GPU MacBook Pros cannot switch external DP/HDMI ports between GPUs if they have Thunderbolt. Furthermore, in multiple places in the DRM subsystem we need to detect whether a GPU is on-board or attached with Thunderbolt. As an example, Thunderbolt-attached GPUs shall not be registered with vga_switcheroo. Intel uses a Vendor-Specific Extended Capability (VSEC) with ID 0x1234 on devices belonging to a Thunderbolt controller which allows us to recognize them. Detect presence of this VSEC on device probe and cache it in a newly added is_thunderbolt bit in struct pci_dev which can then be queried by pci_bridge_d3_possible(), pci_dev_check_d3cold(), apple-gmux and others. Cc: Andreas Noever Cc: Tomas Winkler Cc: Amir Levy Signed-off-by: Lukas Wunner --- drivers/pci/pci.h | 2 ++ drivers/pci/probe.c | 34 ++++++++++++++++++++++++++++++++++ include/linux/pci.h | 1 + 3 files changed, 37 insertions(+) diff --git a/drivers/pci/pci.h b/drivers/pci/pci.h index cb17db2..45c2b81 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 e164b5c..891a8fa 100644 --- a/drivers/pci/probe.c +++ b/drivers/pci/probe.c @@ -1206,6 +1206,37 @@ void set_pcie_hotplug_bridge(struct pci_dev *pdev) pdev->is_hotplug_bridge = 1; } +static void set_pcie_vendor_specific(struct pci_dev *dev) +{ + int vsec = 0; + u32 header; + + while ((vsec = pci_find_next_ext_capability(dev, vsec, + PCI_EXT_CAP_ID_VNDR))) { + pci_read_config_dword(dev, vsec + PCI_VNDR_HEADER, &header); + + /* Is the device part of a Thunderbolt controller? */ + if (dev->vendor == PCI_VENDOR_ID_INTEL && + PCI_VNDR_HEADER_ID(header) == PCI_VSEC_ID_INTEL_TBT) + dev->is_thunderbolt = 1; + } + + /* + * 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. + */ + if (!dev->is_thunderbolt) { + struct pci_dev *parent = dev; + + while ((parent = pci_upstream_bridge(parent))) + if (parent->is_thunderbolt) { + dev->is_thunderbolt = 1; + break; + } + } +} + /** * pci_ext_cfg_is_aliased - is ext config space just an alias of std config? * @dev: PCI device @@ -1358,6 +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_vendor_specific(dev); + /* "Unknown power state" */ dev->current_state = PCI_UNKNOWN; diff --git a/include/linux/pci.h b/include/linux/pci.h index e2d1a12..3c775e8 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; -- 2.10.2