From patchwork Tue Mar 1 04:19:41 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: "David E. Box" X-Patchwork-Id: 12764045 X-Patchwork-Delegate: bhelgaas@google.com 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 E2D92C4332F for ; Tue, 1 Mar 2022 04:19:51 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S232259AbiCAEUa (ORCPT ); Mon, 28 Feb 2022 23:20:30 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:47466 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S232261AbiCAEU1 (ORCPT ); Mon, 28 Feb 2022 23:20:27 -0500 Received: from mga02.intel.com (mga02.intel.com [134.134.136.20]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id E5E9F2C111; Mon, 28 Feb 2022 20:19:47 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=intel.com; i=@intel.com; q=dns/txt; s=Intel; t=1646108387; x=1677644387; h=from:to:cc:subject:date:message-id:in-reply-to: references:mime-version:content-transfer-encoding; bh=AIyzSJ/ML6P0dJudfUlrNMtxGvJXJ1cbc80FGTGSMus=; b=LNOtWDx1OyUdGhDkoye7ee4CkcxOs4Al6IAS5dHwk1qCOQebSp4pAwL2 4SxxiHQIrLxXQktBENt6xdFpe/un8YUrt3uMhQ7RxATvpcSmr0ksqKq6r 0P4IbRZZffGXuDnmcV9Ny24fYiFJMaUbDnpb1bxl0qDKdrSkvxleFwqdU 7NQ/kNGCthNFGRFroP7LDtD4QLNcnKAuy8aa956Ub0greSy8Q+FLyIfPI Qz/7NGNArpB4xfqGf+qIQGqXGUO62pRRoyJNa+MPWkTekhHfbtGOTnZVj LfH/i41yrbvabhY+8v79ZHxiBcFPNLCcozbyIt4ZaQ9XgERMn4kG85Z2e A==; X-IronPort-AV: E=McAfee;i="6200,9189,10272"; a="240463932" X-IronPort-AV: E=Sophos;i="5.90,144,1643702400"; d="scan'208";a="240463932" Received: from orsmga004.jf.intel.com ([10.7.209.38]) by orsmga101.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 28 Feb 2022 20:19:44 -0800 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.90,144,1643702400"; d="scan'208";a="641123501" Received: from linux.intel.com ([10.54.29.200]) by orsmga004.jf.intel.com with ESMTP; 28 Feb 2022 20:19:44 -0800 Received: from debox1-desk4.lan (unknown [10.251.9.202]) by linux.intel.com (Postfix) with ESMTP id C8F3C580C20; Mon, 28 Feb 2022 20:19:43 -0800 (PST) From: "David E. Box" To: nirmal.patel@linux.intel.com, jonathan.derrick@linux.dev, lorenzo.pieralisi@arm.com, hch@infradead.org, kw@linux.com, robh@kernel.org, bhelgaas@google.com, david.e.box@linux.intel.com, michael.a.bottini@linux.intel.com, rafael@kernel.org, me@adhityamohan.in Cc: linux-pci@vger.kernel.org, linux-kernel@vger.kernel.org Subject: [PATCH V6 1/3] PCI/ASPM: Add pci_enable_default_link_state() Date: Mon, 28 Feb 2022 20:19:41 -0800 Message-Id: <20220301041943.2935892-2-david.e.box@linux.intel.com> X-Mailer: git-send-email 2.25.1 In-Reply-To: <20220301041943.2935892-1-david.e.box@linux.intel.com> References: <20220301041943.2935892-1-david.e.box@linux.intel.com> MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: linux-pci@vger.kernel.org From: Michael Bottini Add pci_enable_default_link_state() to allow devices to change the default BIOS configured states. Clears the BIOS default settings then sets the new states and reconfigures the link under the semaphore. Also add PCIE_LINK_STATE_ALL macro for convenience for callers that want to enable all link states. Signed-off-by: Michael Bottini Signed-off-by: David E. Box Acked-by: Bjorn Helgaas --- V6 - No change V5 - Rename to pci_enable_default_link_state and model after pci_disable_link_state() as suggested by Bjorn. - Add helper PCIE_LINK_STATE_ALL which sets bits for all links states and clock pm. - Clarify commit language to indicate the function changes the default link states (not ASPM policy). V4 - Refactor vmd_enable_apsm() to exit early, making the lines shorter and more readable. Suggested by Christoph. V3 - No changes V2 - Use return status to print pci_info message if ASPM cannot be enabled. - Add missing static declaration, caught by lkp@intel.com drivers/pci/pcie/aspm.c | 54 +++++++++++++++++++++++++++++++++++++++++ include/linux/pci.h | 7 ++++++ 2 files changed, 61 insertions(+) diff --git a/drivers/pci/pcie/aspm.c b/drivers/pci/pcie/aspm.c index a96b7424c9bc..b2752851b1ba 100644 --- a/drivers/pci/pcie/aspm.c +++ b/drivers/pci/pcie/aspm.c @@ -1132,6 +1132,60 @@ int pci_disable_link_state(struct pci_dev *pdev, int state) } EXPORT_SYMBOL(pci_disable_link_state); +/** + * pci_enable_default_link_state - Clears and sets the default device link state + * so that the link may be allowed to enter the specified 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. Also note that this does not enable + * states disabled by pci_disable_link_state(). Returns 0 or a negative errno. + * + * @pdev: PCI device + * @state: Mask of ASPM link states to enable + */ +int pci_enable_default_link_state(struct pci_dev *pdev, int state) +{ + struct pcie_link_state *link = pcie_aspm_get_link(pdev); + + if (!link) + return -EINVAL; + /* + * A driver requested that ASPM be enabled 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. + */ + if (aspm_disabled) { + pci_warn(pdev, "can't override BIOS ASPM; OS doesn't have ASPM control\n"); + return -EPERM; + } + + down_read(&pci_bus_sem); + mutex_lock(&aspm_lock); + link->aspm_default = 0; + if (state & PCIE_LINK_STATE_L0S) + link->aspm_default |= ASPM_STATE_L0S; + if (state & PCIE_LINK_STATE_L1) + /* L1 PM substates require L1 */ + link->aspm_default |= ASPM_STATE_L1 | ASPM_STATE_L1SS; + if (state & PCIE_LINK_STATE_L1_1) + link->aspm_default |= ASPM_STATE_L1_1; + if (state & PCIE_LINK_STATE_L1_2) + link->aspm_default |= ASPM_STATE_L1_2; + if (state & PCIE_LINK_STATE_L1_1_PCIPM) + link->aspm_default |= ASPM_STATE_L1_1_PCIPM; + if (state & PCIE_LINK_STATE_L1_2_PCIPM) + link->aspm_default |= ASPM_STATE_L1_2_PCIPM; + pcie_config_aspm_link(link, policy_to_aspm_state(link)); + + link->clkpm_default = (state & PCIE_LINK_STATE_CLKPM) ? 1 : 0; + pcie_set_clkpm(link, policy_to_clkpm_state(link)); + mutex_unlock(&aspm_lock); + up_read(&pci_bus_sem); + + return 0; +} +EXPORT_SYMBOL(pci_enable_default_link_state); + static int pcie_aspm_set_policy(const char *val, const struct kernel_param *kp) { diff --git a/include/linux/pci.h b/include/linux/pci.h index 8253a5413d7c..fd710afe0209 100644 --- a/include/linux/pci.h +++ b/include/linux/pci.h @@ -1641,10 +1641,15 @@ extern bool pcie_ports_native; #define PCIE_LINK_STATE_L1_2 BIT(4) #define PCIE_LINK_STATE_L1_1_PCIPM BIT(5) #define PCIE_LINK_STATE_L1_2_PCIPM BIT(6) +#define PCIE_LINK_STATE_ALL (PCIE_LINK_STATE_L0S | PCIE_LINK_STATE_L1 |\ + PCIE_LINK_STATE_CLKPM | PCIE_LINK_STATE_L1_1 |\ + PCIE_LINK_STATE_L1_2 | PCIE_LINK_STATE_L1_1_PCIPM |\ + PCIE_LINK_STATE_L1_2_PCIPM) #ifdef CONFIG_PCIEASPM int pci_disable_link_state(struct pci_dev *pdev, int state); int pci_disable_link_state_locked(struct pci_dev *pdev, int state); +int pci_enable_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); @@ -1653,6 +1658,8 @@ static inline int pci_disable_link_state(struct pci_dev *pdev, int state) { return 0; } static inline int pci_disable_link_state_locked(struct pci_dev *pdev, int state) { return 0; } +static inline int pci_enable_default_link_state(struct pci_dev *pdev, int state) +{ return 0; } static inline void pcie_no_aspm(void) { } static inline bool pcie_aspm_support_enabled(void) { return false; } static inline bool pcie_aspm_enabled(struct pci_dev *pdev) { return false; }