From patchwork Thu Nov 3 02:18:19 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: 13029398 X-Patchwork-Delegate: lorenzo.pieralisi@arm.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 E6F34C433FE for ; Thu, 3 Nov 2022 02:18:29 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S230314AbiKCCS2 (ORCPT ); Wed, 2 Nov 2022 22:18:28 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:56158 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S230207AbiKCCS1 (ORCPT ); Wed, 2 Nov 2022 22:18:27 -0400 Received: from mga07.intel.com (mga07.intel.com [134.134.136.100]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 721852618; Wed, 2 Nov 2022 19:18:24 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=intel.com; i=@intel.com; q=dns/txt; s=Intel; t=1667441905; x=1698977905; h=from:to:cc:subject:date:message-id:in-reply-to: references:mime-version:content-transfer-encoding; bh=vzUI8zH+fYLJwczHSdbiw1/5l9LlQMI1ESll22EfjJI=; b=QmTz1hTHIb+yN2slhY+HSOi6ZVrWLgup6gAHG1HZEUvZ8Opy1vOjOIY2 gKpgQkAc1uo1WaKGsdQYFX+Yy/iq1MHzJgiiW2Jex5v4yW0QJd7VqrONf 8WIQLCNduJnojVdWvt6nau5D9/c48X3KgTE2Tp3/CQ8eiUR6VxqFm9S8g RViAPgyzk+++taagSjfQuZ6NJ9/alBW7e4FIvJanRsseUdzyK5MsPFI9P WSXMt650HNIjiK9WB8UDB0+bWM3tu7AV7nCkB5ljpWDBfnrbOtITGyNW/ Zj8+rbcuN44uwYh6KV/09XY9xIq02Q+HNVKjB4OUEKNJWuTZBbEl/43bd g==; X-IronPort-AV: E=McAfee;i="6500,9779,10519"; a="373794791" X-IronPort-AV: E=Sophos;i="5.95,235,1661842800"; d="scan'208";a="373794791" Received: from orsmga008.jf.intel.com ([10.7.209.65]) by orsmga105.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 02 Nov 2022 19:18:23 -0700 X-ExtLoop1: 1 X-IronPort-AV: E=McAfee;i="6500,9779,10519"; a="665784357" X-IronPort-AV: E=Sophos;i="5.95,235,1661842800"; d="scan'208";a="665784357" Received: from linux.intel.com ([10.54.29.200]) by orsmga008.jf.intel.com with ESMTP; 02 Nov 2022 19:18:22 -0700 Received: from debox1-desk4.intel.com (unknown [10.212.195.54]) by linux.intel.com (Postfix) with ESMTP id 94B3B580B9E; Wed, 2 Nov 2022 19:18:22 -0700 (PDT) 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@intel.com, rafael@kernel.org, me@adhityamohan.in Cc: linux-pci@vger.kernel.org, linux-kernel@vger.kernel.org Subject: [PATCH V8 1/4] PCI/ASPM: Add pci_enable_link_state() Date: Wed, 2 Nov 2022 19:18:19 -0700 Message-Id: <20221103021822.308586-2-david.e.box@linux.intel.com> X-Mailer: git-send-email 2.25.1 In-Reply-To: <20221103021822.308586-1-david.e.box@linux.intel.com> References: <20221103021822.308586-1-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_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 --- V8 - No change V7 - Fix description as suggested by Bjorn - Rename function to pci_enable_link_state 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 53a1fa306e1e..339c686a5094 100644 --- a/drivers/pci/pcie/aspm.c +++ b/drivers/pci/pcie/aspm.c @@ -1181,6 +1181,60 @@ int pci_disable_link_state(struct pci_dev *pdev, int state) } EXPORT_SYMBOL(pci_disable_link_state); +/** + * pci_enable_link_state - Clear and set 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(). Return 0 or a negative errno. + * + * @pdev: PCI device + * @state: Mask of ASPM link states to enable + */ +int pci_enable_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_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 2bda4a4e47e8..8c35f15e6012 100644 --- a/include/linux/pci.h +++ b/include/linux/pci.h @@ -1651,10 +1651,15 @@ 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_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); @@ -1663,6 +1668,8 @@ 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_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; }