From patchwork Fri Oct 28 08:52:06 2016 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Lukas Wunner X-Patchwork-Id: 688293 Return-Path: X-Original-To: incoming@patchwork.ozlabs.org Delivered-To: patchwork-incoming@bilbo.ozlabs.org Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by ozlabs.org (Postfix) with ESMTP id 3t4yJR5QG9z9t0Z for ; Fri, 28 Oct 2016 19:55:19 +1100 (AEDT) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S964836AbcJ1IzS (ORCPT ); Fri, 28 Oct 2016 04:55:18 -0400 Received: from mailout1.hostsharing.net ([83.223.95.204]:37475 "EHLO mailout1.hostsharing.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S964827AbcJ1IzR (ORCPT ); Fri, 28 Oct 2016 04:55:17 -0400 Received: from h08.hostsharing.net (h08.hostsharing.net [83.223.95.28]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mailout1.hostsharing.net (Postfix) with ESMTPS id 13B39101B21F0; Fri, 28 Oct 2016 10:55:15 +0200 (CEST) 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 B9365600BBDA; Fri, 28 Oct 2016 10:55:12 +0200 (CEST) X-Mailbox-Line: From be3453a6110c483d0fd3d413ae4c04a3fd44537a Mon Sep 17 00:00:00 2001 Message-Id: In-Reply-To: References: From: Lukas Wunner Date: Fri, 28 Oct 2016 10:52:06 +0200 Subject: [PATCH v2 8/9] ACPI / hotplug / PCI: Make device_is_managed_by_native_pciehp() public To: linux-pci@vger.kernel.org, linux-pm@vger.kernel.org, Bjorn Helgaas Cc: Mika Westerberg , "Rafael J. Wysocki" , Andreas Noever , Keith Busch Sender: linux-pci-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-pci@vger.kernel.org We're about to add runtime PM of hotplug ports, but we need to restrict it to ports that are handled natively by the OS: If they're handled by the firmware (which is the case for Thunderbolt on non-Macs), things would break if the OS put the ports into D3hot behind the firmware's back. To determine if a hotplug port is handled natively, one has to walk up from the port to the root bridge and check the cached _OSC Control Field for the value of the "PCI Express Native Hot Plug control" bit. There's already a function to do that, device_is_managed_by_native_pciehp(), but it's private to drivers/pci/hotplug/acpiphp_glue.c and only compiled in if CONFIG_HOTPLUG_PCI_ACPI is enabled. Make it public and move it to drivers/pci/pci-acpi.c, so that it is available in the more general CONFIG_ACPI case. The function contains a check if the device in question is a hotplug port and returns false if it's not. The caller we're going to add doesn't need this as it only calls the function if it actually *is* a hotplug port. Move the check out of the function into the single existing caller. Give the function a shorter name and add some kerneldoc and polish. No functional change intended. Tested-by: Mika Westerberg Reviewed-by: Rafael J. Wysocki Signed-off-by: Lukas Wunner --- drivers/pci/hotplug/acpiphp_glue.c | 28 +--------------------------- drivers/pci/pci-acpi.c | 24 ++++++++++++++++++++++++ include/linux/pci_hotplug.h | 2 ++ 3 files changed, 27 insertions(+), 27 deletions(-) diff --git a/drivers/pci/hotplug/acpiphp_glue.c b/drivers/pci/hotplug/acpiphp_glue.c index b286a56..5ed2dca 100644 --- a/drivers/pci/hotplug/acpiphp_glue.c +++ b/drivers/pci/hotplug/acpiphp_glue.c @@ -222,32 +222,6 @@ static void acpiphp_post_dock_fixup(struct acpi_device *adev) acpiphp_let_context_go(context); } -/* Check whether the PCI device is managed by native PCIe hotplug driver */ -static bool device_is_managed_by_native_pciehp(struct pci_dev *pdev) -{ - acpi_handle tmp; - struct acpi_pci_root *root; - - /* Check whether the PCIe port supports native PCIe hotplug */ - if (!pdev->is_hotplug_bridge) - return false; - - /* - * Check whether native PCIe hotplug has been enabled for - * this PCIe hierarchy. - */ - tmp = acpi_find_root_bridge_handle(pdev); - if (!tmp) - return false; - root = acpi_pci_find_root(tmp); - if (!root) - return false; - if (!(root->osc_control_set & OSC_PCI_EXPRESS_NATIVE_HP_CONTROL)) - return false; - - return true; -} - /** * acpiphp_add_context - Add ACPIPHP context to an ACPI device object. * @handle: ACPI handle of the object to add a context to. @@ -331,7 +305,7 @@ static acpi_status acpiphp_add_context(acpi_handle handle, u32 lvl, void *data, * expose slots to user space in those cases. */ if ((acpi_pci_check_ejectable(pbus, handle) || is_dock_device(adev)) - && !(pdev && device_is_managed_by_native_pciehp(pdev))) { + && !(pdev && pdev->is_hotplug_bridge && pciehp_is_native(pdev))) { unsigned long long sun; int retval; diff --git a/drivers/pci/pci-acpi.c b/drivers/pci/pci-acpi.c index d966d47..ed3daa8 100644 --- a/drivers/pci/pci-acpi.c +++ b/drivers/pci/pci-acpi.c @@ -294,6 +294,30 @@ int pci_get_hp_params(struct pci_dev *dev, struct hotplug_params *hpp) EXPORT_SYMBOL_GPL(pci_get_hp_params); /** + * pciehp_is_native - Check whether a hotplug port is handled by the OS + * @pdev: Hotplug port to check + * + * Walk up from @pdev to the host bridge, obtain its cached _OSC Control Field + * and return the value of the "PCI Express Native Hot Plug control" bit. + * On failure to obtain the _OSC Control Field return %false. + */ +bool pciehp_is_native(struct pci_dev *pdev) +{ + struct acpi_pci_root *root; + acpi_handle handle; + + handle = acpi_find_root_bridge_handle(pdev); + if (!handle) + return false; + + root = acpi_pci_find_root(handle); + if (!root) + return false; + + return root->osc_control_set & OSC_PCI_EXPRESS_NATIVE_HP_CONTROL; +} + +/** * pci_acpi_wake_bus - Root bus wakeup notification fork function. * @work: Work item to handle. */ diff --git a/include/linux/pci_hotplug.h b/include/linux/pci_hotplug.h index 8c78950..2e855af 100644 --- a/include/linux/pci_hotplug.h +++ b/include/linux/pci_hotplug.h @@ -176,6 +176,7 @@ struct hotplug_params { #ifdef CONFIG_ACPI #include int pci_get_hp_params(struct pci_dev *dev, struct hotplug_params *hpp); +bool pciehp_is_native(struct pci_dev *pdev); int acpi_get_hp_hw_control_from_firmware(struct pci_dev *dev, u32 flags); int acpi_pci_check_ejectable(struct pci_bus *pbus, acpi_handle handle); int acpi_pci_detect_ejectable(acpi_handle handle); @@ -185,5 +186,6 @@ static inline int pci_get_hp_params(struct pci_dev *dev, { return -ENODEV; } +static inline bool pciehp_is_native(struct pci_dev *pdev) { return true; } #endif #endif