From patchwork Fri Mar 10 20:23:45 2017 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Lukas Wunner X-Patchwork-Id: 9617911 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 715AD60415 for ; Fri, 10 Mar 2017 20:24:15 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 7075B2877C for ; Fri, 10 Mar 2017 20:24:15 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id 64ABD2879A; Fri, 10 Mar 2017 20:24:15 +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=-4.2 required=2.0 tests=BAYES_00, RCVD_IN_DNSWL_MED autolearn=ham version=3.3.1 Received: from gabe.freedesktop.org (gabe.freedesktop.org [131.252.210.177]) (using TLSv1.2 with cipher DHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.wl.linuxfoundation.org (Postfix) with ESMTPS id D97152877C for ; Fri, 10 Mar 2017 20:24:14 +0000 (UTC) Received: from gabe.freedesktop.org (localhost [127.0.0.1]) by gabe.freedesktop.org (Postfix) with ESMTP id EB3596EED9; Fri, 10 Mar 2017 20:24:13 +0000 (UTC) X-Original-To: dri-devel@lists.freedesktop.org Delivered-To: dri-devel@lists.freedesktop.org Received: from mailout2.hostsharing.net (mailout2.hostsharing.net [83.223.90.233]) by gabe.freedesktop.org (Postfix) with ESMTPS id 35FB66EED9 for ; Fri, 10 Mar 2017 20:24:12 +0000 (UTC) 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 182C31008C932; Fri, 10 Mar 2017 21:24:13 +0100 (CET) Received: from localhost (5-38-90-81.adsl.cmo.de [81.90.38.5]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-SHA (128/128 bits)) (No client certificate requested) by h08.hostsharing.net (Postfix) with ESMTPSA id 85C8E612CA66; Fri, 10 Mar 2017 21:24:08 +0100 (CET) X-Mailbox-Line: From 0ab165a4a35c0b60f29d4c306c653ead14fcd8f9 Mon Sep 17 00:00:00 2001 Message-Id: <0ab165a4a35c0b60f29d4c306c653ead14fcd8f9.1489145162.git.lukas@wunner.de> In-Reply-To: References: From: Lukas Wunner Date: Fri, 10 Mar 2017 21:23:45 +0100 Subject: [PATCH v2 1/5] PCI: Recognize Thunderbolt devices To: dri-devel@lists.freedesktop.org, Daniel Vetter Cc: Bjorn Helgaas X-BeenThere: dri-devel@lists.freedesktop.org X-Mailman-Version: 2.1.18 Precedence: list List-Id: Direct Rendering Infrastructure - Development List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , MIME-Version: 1.0 Errors-To: dri-devel-bounces@lists.freedesktop.org Sender: "dri-devel" X-Virus-Scanned: ClamAV using ClamSMTP Detect on probe whether a PCI device is part of a Thunderbolt controller. Intel uses a Vendor-Specific Extended Capability (VSEC) with ID 0x1234 on such devices. Detect presence of this VSEC and cache it in a newly added is_thunderbolt bit in struct pci_dev. Also, add a helper to check whether a given PCI device is situated on a Thunderbolt daisy chain (i.e., below a PCI device with is_thunderbolt set). The necessity arises from the following: * If an external Thunderbolt GPU is connected to a dual GPU laptop, 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 on a Thunderbolt daisy chain. * 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. v2: Make kerneldoc for pci_is_thunderbolt_attached() more precise, drop portion of commit message pertaining to separate series. (Bjorn Helgaas) Cc: Andreas Noever Cc: Michael Jamet Cc: Tomas Winkler Cc: Amir Levy Acked-by: Bjorn Helgaas Signed-off-by: Lukas Wunner --- drivers/pci/pci.h | 2 ++ drivers/pci/probe.c | 21 +++++++++++++++++++++ include/linux/pci.h | 23 +++++++++++++++++++++++ 3 files changed, 46 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..7963ecc6d85f 100644 --- a/drivers/pci/probe.c +++ b/drivers/pci/probe.c @@ -1208,6 +1208,24 @@ void set_pcie_hotplug_bridge(struct pci_dev *pdev) pdev->is_hotplug_bridge = 1; } +static void set_pcie_thunderbolt(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; + return; + } + } +} + /** * pci_ext_cfg_is_aliased - is ext config space just an alias of std config? * @dev: PCI device @@ -1360,6 +1378,9 @@ 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..a37ecd52b35b 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; /* Thunderbolt controller */ unsigned int __aer_firmware_first_valid:1; unsigned int __aer_firmware_first:1; unsigned int broken_intx_masking:1; @@ -2171,6 +2172,28 @@ static inline bool pci_ari_enabled(struct pci_bus *bus) return bus->self && bus->self->ari_enabled; } +/** + * pci_is_thunderbolt_attached - whether device is on a Thunderbolt daisy chain + * @pdev: PCI device to check + * + * Walk upwards from @pdev and check for each encountered bridge if it's part + * of a Thunderbolt controller. Reaching the host bridge means @pdev is not + * Thunderbolt-attached. (But rather soldered to the mainboard usually.) + */ +static inline bool pci_is_thunderbolt_attached(struct pci_dev *pdev) +{ + struct pci_dev *parent = pdev; + + if (pdev->is_thunderbolt) + return true; + + while ((parent = pci_upstream_bridge(parent))) + if (parent->is_thunderbolt) + return true; + + return false; +} + /* provide the legacy pci_dma_* API */ #include