From nobody Fri Sep 20 20:35:04 2024 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id B054EC7EE2C for ; Fri, 2 Jun 2023 11:49:33 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S234510AbjFBLtb (ORCPT ); Fri, 2 Jun 2023 07:49:31 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:37128 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S235014AbjFBLt0 (ORCPT ); Fri, 2 Jun 2023 07:49:26 -0400 Received: from mga09.intel.com (mga09.intel.com [134.134.136.24]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id A548310E7; Fri, 2 Jun 2023 04:48:54 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=intel.com; i=@intel.com; q=dns/txt; s=Intel; t=1685706534; x=1717242534; h=from:to:cc:subject:date:message-id:in-reply-to: references:mime-version:content-transfer-encoding; bh=BtruzGycmKqs9ry1ncyoa7VfbvISx5ML/zzcyrdoo7U=; b=Dif17jcG+INVFOdVOZPq6DTykGF3oT/7onDc4tC50jjBvtYh3axKZRE0 wngS+63tHSYUwRzxGX2VCRzP/WzNMwb2jgCc05rYmZJpvVlaIaV2x/yxd b8cJFCUPUygBdqqiFpy9wOFP5AgTZNy486aIUn3u4fqm/dZMm1mAIj562 Ir+fe3b3NW5GRBBM1hMtIWiGDWbmhRL1IbHqZMK6fZeSyWfjGwB/ZR3O2 yaTC2CLIjCAft2xCpFpa8/ZM5aHOeopFt3a+s2bstyc3wRJoabZKZK/Sb VZjw4U9aoiqyD7584gMOfh0OaWwb9tn4hGtZeO1Hlj4LGQ0B9xXLuwlaq Q==; X-IronPort-AV: E=McAfee;i="6600,9927,10728"; a="358279663" X-IronPort-AV: E=Sophos;i="6.00,212,1681196400"; d="scan'208";a="358279663" Received: from orsmga002.jf.intel.com ([10.7.209.21]) by orsmga102.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 02 Jun 2023 04:48:29 -0700 X-ExtLoop1: 1 X-IronPort-AV: E=McAfee;i="6600,9927,10728"; a="707819437" X-IronPort-AV: E=Sophos;i="6.00,212,1681196400"; d="scan'208";a="707819437" Received: from rspatil-mobl3.gar.corp.intel.com (HELO ijarvine-MOBL2.ger.corp.intel.com) ([10.251.208.112]) by orsmga002-auth.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 02 Jun 2023 04:48:24 -0700 From: =?UTF-8?q?Ilpo=20J=C3=A4rvinen?= To: linux-pci@vger.kernel.org, Bjorn Helgaas , Lorenzo Pieralisi , Rob Herring , =?UTF-8?q?Krzysztof=20Wilczy=C5=84ski?= , Lukas Wunner , "Rafael J . Wysocki" , Heiner Kallweit , Emmanuel Grumbach , Bjorn Helgaas , linux-kernel@vger.kernel.org Cc: =?UTF-8?q?Ilpo=20J=C3=A4rvinen?= Subject: [RFC PATCH v1 05/13] PCI/ASPM: Add pci_enable_link_state() Date: Fri, 2 Jun 2023 14:47:42 +0300 Message-Id: <20230602114751.19671-6-ilpo.jarvinen@linux.intel.com> X-Mailer: git-send-email 2.30.2 In-Reply-To: <20230602114751.19671-1-ilpo.jarvinen@linux.intel.com> References: <20230602114751.19671-1-ilpo.jarvinen@linux.intel.com> MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: quoted-printable Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org pci_disable_link_state() lacks a symmetric pair. Some drivers want to disable ASPM during certain phases of their operation but then re-enable it later on. If pci_disable_link_state() is made for the device, there is currently no way to re-enable the states that were disabled. Add pci_enable_link_state() to remove ASPM states from the state disable mask. Signed-off-by: Ilpo J=C3=A4rvinen --- drivers/pci/pcie/aspm.c | 44 +++++++++++++++++++++++++++++++++++++++++ include/linux/pci.h | 2 ++ 2 files changed, 46 insertions(+) diff --git a/drivers/pci/pcie/aspm.c b/drivers/pci/pcie/aspm.c index 4727f73a2d0d..aed59ab13c46 100644 --- a/drivers/pci/pcie/aspm.c +++ b/drivers/pci/pcie/aspm.c @@ -1165,6 +1165,50 @@ int pci_disable_link_state(struct pci_dev *pdev, int= state) } EXPORT_SYMBOL(pci_disable_link_state); =20 +/** + * pci_enable_link_state - Re-enable device's link state + * @pdev: PCI device + * @state: ASPM link states to re-enable + * + * Enable device's link state that were previously disable so the link is + * allowed to enter the specific states. Note that if the BIOS didn't grant + * ASPM control to the OS, this does nothing because we can't touch the + * LNKCTL register. + * + * Return: 0 or a negative errno. + */ +int pci_enable_link_state(struct pci_dev *pdev, int state) +{ + struct pcie_link_state *link =3D pcie_aspm_get_link(pdev); + + if (!link) + return -EINVAL; + /* + * A driver requested that ASPM be disabled on this device, but + * if we don't have permission to manage ASPM (e.g., on ACPI + * systems we have to observe the FADT ACPI_FADT_NO_ASPM bit and + * the _OSC method), we can't honor that request. Windows has + * a similar mechanism using "PciASPMOptOut", which is also + * ignored in this situation. + */ + if (aspm_disabled) { + pci_warn(pdev, "can't enable ASPM; OS doesn't have ASPM control\n"); + return -EPERM; + } + + mutex_lock(&aspm_lock); + link->aspm_disable &=3D ~pci_link_state_mask(state); + pcie_config_aspm_link(link, policy_to_aspm_state(link)); + + if (state & PCIE_LINK_STATE_CLKPM) + link->clkpm_disable =3D 0; + pcie_set_clkpm(link, policy_to_clkpm_state(link)); + mutex_unlock(&aspm_lock); + + return 0; +} +EXPORT_SYMBOL(pci_enable_link_state); + /** * pci_set_default_link_state - Set the default device link state * @pdev: PCI device diff --git a/include/linux/pci.h b/include/linux/pci.h index 5597e97a086d..aec259d12ca0 100644 --- a/include/linux/pci.h +++ b/include/linux/pci.h @@ -1777,11 +1777,13 @@ extern bool pcie_ports_native; int pci_disable_link_state(struct pci_dev *pdev, int state); int pci_disable_link_state_locked(struct pci_dev *pdev, int state); #ifdef CONFIG_PCIEASPM +int pci_enable_link_state(struct pci_dev *pdev, int state); int pci_set_default_link_state(struct pci_dev *pdev, int state); void pcie_no_aspm(void); bool pcie_aspm_support_enabled(void); bool pcie_aspm_enabled(struct pci_dev *pdev); #else +static inline int pci_enable_link_state(struct pci_dev *pdev, int state) {= return -EOPNOTSUPP; } static inline int pci_set_default_link_state(struct pci_dev *pdev, int sta= te) { return 0; } static inline void pcie_no_aspm(void) { } --=20 2.30.2