From patchwork Thu Sep 6 15:50:20 2018 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Mika Westerberg X-Patchwork-Id: 10590763 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-2.web.codeaurora.org (Postfix) with ESMTP id B215F69B3 for ; Thu, 6 Sep 2018 15:50:32 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id A89202AE7F for ; Thu, 6 Sep 2018 15:50:32 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id 9C07B2AE7A; Thu, 6 Sep 2018 15:50:32 +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=-7.9 required=2.0 tests=BAYES_00,MAILING_LIST_MULTI, RCVD_IN_DNSWL_HI autolearn=unavailable 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 21CFE2AE95 for ; Thu, 6 Sep 2018 15:50:32 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1730385AbeIFU0h (ORCPT ); Thu, 6 Sep 2018 16:26:37 -0400 Received: from mga09.intel.com ([134.134.136.24]:47546 "EHLO mga09.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1730376AbeIFU0h (ORCPT ); Thu, 6 Sep 2018 16:26:37 -0400 X-Amp-Result: SKIPPED(no attachment in message) X-Amp-File-Uploaded: False Received: from orsmga007.jf.intel.com ([10.7.209.58]) by orsmga102.jf.intel.com with ESMTP/TLS/DHE-RSA-AES256-GCM-SHA384; 06 Sep 2018 08:50:29 -0700 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.53,338,1531810800"; d="scan'208";a="70878674" Received: from black.fi.intel.com ([10.237.72.28]) by orsmga007.jf.intel.com with ESMTP; 06 Sep 2018 08:50:25 -0700 Received: by black.fi.intel.com (Postfix, from userid 1001) id 4417A601; Thu, 6 Sep 2018 18:50:21 +0300 (EEST) From: Mika Westerberg To: Bjorn Helgaas , "Rafael J. Wysocki" Cc: Len Brown , Lukas Wunner , Keith Busch , Ashok Raj , Mario.Limonciello@dell.com, Anthony Wong , "D . J . Bernstein" , Linus Walleij , Mika Westerberg , linux-pci@vger.kernel.org, linux-acpi@vger.kernel.org Subject: [PATCH 10/10] PCI / ACPI: Whitelist D3 for more PCIe hotplug ports Date: Thu, 6 Sep 2018 18:50:20 +0300 Message-Id: <20180906155020.51700-11-mika.westerberg@linux.intel.com> X-Mailer: git-send-email 2.18.0 In-Reply-To: <20180906155020.51700-1-mika.westerberg@linux.intel.com> References: <20180906155020.51700-1-mika.westerberg@linux.intel.com> 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 In order to have better power management for Thunderbolt PCIe chains, Windows enables power management for native PCIe hotplug ports if there is following ACPI _DSD attached to the root port: Name (_DSD, Package () { ToUUID ("6211e2c0-58a3-4af3-90e1-927a4e0c55a4"), Package () { Package () {"HotPlugSupportInD3", 1} } }) This is also documented in: https://docs.microsoft.com/en-us/windows-hardware/drivers/pci/dsd-for-pcie-root-ports#identifying-pcie-root-ports-supporting-hot-plug-in-d3 Do the same in Linux by introducing new firmware PM callback (->bridge_d3()) and then implement it for ACPI based systems so that the above property is checked. There is one catch, though. The initial pci_dev->bridge_d3 is set before the root port has ACPI companion bound (the device is not added to the PCI bus either) so we need to look up the ACPI companion manually in that case in acpi_pci_bridge_d3(). Signed-off-by: Mika Westerberg Reviewed-by: Rafael J. Wysocki --- drivers/acpi/property.c | 3 +++ drivers/pci/pci-acpi.c | 41 +++++++++++++++++++++++++++++++++++++++++ drivers/pci/pci.c | 9 +++++++++ drivers/pci/pci.h | 3 +++ 4 files changed, 56 insertions(+) diff --git a/drivers/acpi/property.c b/drivers/acpi/property.c index f3ddb279d2de..f9d63ee9f623 100644 --- a/drivers/acpi/property.c +++ b/drivers/acpi/property.c @@ -28,6 +28,9 @@ static const guid_t prp_guids[] = { /* ACPI _DSD device properties GUID: daffd814-6eba-4d8c-8a91-bc9bbf4aa301 */ GUID_INIT(0xdaffd814, 0x6eba, 0x4d8c, 0x8a, 0x91, 0xbc, 0x9b, 0xbf, 0x4a, 0xa3, 0x01), + /* Hotplug in D3 GUID: 6211e2c0-58a3-4af3-90e1-927a4e0c55a4 */ + GUID_INIT(0x6211e2c0, 0x58a3, 0x4af3, + 0x90, 0xe1, 0x92, 0x7a, 0x4e, 0x0c, 0x55, 0xa4), }; static const guid_t ads_guid = diff --git a/drivers/pci/pci-acpi.c b/drivers/pci/pci-acpi.c index a4a8c02deaa0..c0394232fd93 100644 --- a/drivers/pci/pci-acpi.c +++ b/drivers/pci/pci-acpi.c @@ -519,6 +519,46 @@ static pci_power_t acpi_pci_choose_state(struct pci_dev *pdev) return PCI_POWER_ERROR; } +static struct acpi_device *acpi_pci_find_companion(struct device *dev); + +static bool acpi_pci_bridge_d3(struct pci_dev *dev) +{ + const struct fwnode_handle *fwnode; + struct acpi_device *adev; + struct pci_dev *root; + u8 val; + + if (!dev->is_hotplug_bridge) + return false; + + /* + * Look for a special _DSD property for the root port and if it + * is set we know the hierarchy behind it supports D3 just fine. + */ + root = pci_find_pcie_root_port(dev); + if (!root) + return false; + + adev = ACPI_COMPANION(&root->dev); + if (root == dev) { + /* + * It is possible that the ACPI companion is not yet bound + * for the root port so look it up manually here. + */ + if (!adev && !pci_dev_is_added(root)) + adev = acpi_pci_find_companion(&root->dev); + } + + if (!adev) + return false; + + fwnode = acpi_fwnode_handle(adev); + if (fwnode_property_read_u8(fwnode, "HotPlugSupportInD3", &val)) + return false; + + return val == 1; +} + static bool acpi_pci_power_manageable(struct pci_dev *dev) { struct acpi_device *adev = ACPI_COMPANION(&dev->dev); @@ -635,6 +675,7 @@ static bool acpi_pci_need_resume(struct pci_dev *dev) } static const struct pci_platform_pm_ops acpi_pci_platform_pm = { + .bridge_d3 = acpi_pci_bridge_d3, .is_manageable = acpi_pci_power_manageable, .set_state = acpi_pci_set_power_state, .get_state = acpi_pci_get_power_state, diff --git a/drivers/pci/pci.c b/drivers/pci/pci.c index 074f3f0253f9..ce212eb10be9 100644 --- a/drivers/pci/pci.c +++ b/drivers/pci/pci.c @@ -791,6 +791,11 @@ static inline bool platform_pci_need_resume(struct pci_dev *dev) return pci_platform_pm ? pci_platform_pm->need_resume(dev) : false; } +static inline bool platform_pci_bridge_d3(struct pci_dev *dev) +{ + return pci_platform_pm ? pci_platform_pm->bridge_d3(dev) : false; +} + /** * pci_raw_set_power_state - Use PCI PM registers to set the power state of * given PCI device @@ -2513,6 +2518,10 @@ bool pci_bridge_d3_possible(struct pci_dev *bridge) if (bridge->is_thunderbolt) return true; + /* Platform might know better if the bridge supports D3 */ + if (platform_pci_bridge_d3(bridge)) + return true; + /* * Hotplug ports handled natively by the OS were not validated * by vendors for runtime D3 at least until 2018 because there diff --git a/drivers/pci/pci.h b/drivers/pci/pci.h index 6e0d1528d471..66fd5c1bf71b 100644 --- a/drivers/pci/pci.h +++ b/drivers/pci/pci.h @@ -39,6 +39,8 @@ int pci_bridge_secondary_bus_reset(struct pci_dev *dev); /** * struct pci_platform_pm_ops - Firmware PM callbacks * + * @bridge_d3: Does the bridge allow entering into D3 + * * @is_manageable: returns 'true' if given device is power manageable by the * platform firmware * @@ -60,6 +62,7 @@ int pci_bridge_secondary_bus_reset(struct pci_dev *dev); * these callbacks are mandatory. */ struct pci_platform_pm_ops { + bool (*bridge_d3)(struct pci_dev *dev); bool (*is_manageable)(struct pci_dev *dev); int (*set_state)(struct pci_dev *dev, pci_power_t state); pci_power_t (*get_state)(struct pci_dev *dev);