From nobody Sun Dec 14 11:53:30 2025 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 67CB9C67871 for ; Tue, 25 Oct 2022 01:20:00 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S231126AbiJYBT5 (ORCPT ); Mon, 24 Oct 2022 21:19:57 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:58500 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S231782AbiJYBT3 (ORCPT ); Mon, 24 Oct 2022 21:19:29 -0400 Received: from mga06.intel.com (mga06b.intel.com [134.134.136.31]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id A2FFC658E; Mon, 24 Oct 2022 17:44:12 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=intel.com; i=@intel.com; q=dns/txt; s=Intel; t=1666658652; x=1698194652; h=from:to:cc:subject:date:message-id:in-reply-to: references:mime-version:content-transfer-encoding; bh=qZzEbgnI+IiYGCDWjiOk6pRpfVWyVLmJiJjhJ8Aas6k=; b=BwGQLUl9DDnxzENZWqrhhE9I8bVh6OuIlqmoLTzH5+mUE72/LQjAEKbV TSqhNDX86TN7887Vpo0grbcNjECIbIvRU2L8vjYw99zeEg5iNNciZWwyt /eAuBMWHQHUA7abUa9G93yb4xAaiuXbqvfvwrItvosz7K2xzOH6nlzV/R CITJaYpZ7c8IE8BwvkA2TuVRinU65imoeUEsQ3901gwer6R8dp0fnLZo9 qABSqUsbkYT/zc05ubaSLJ3UiDKo68nw34wrfogIPlzqE4DgRNxZ65zfK /0vv1WIgKmpGR2HUHJ7vg1wMBIk9gsy+ByqTPLM01Kje6B2/YXltQAryr w==; X-IronPort-AV: E=McAfee;i="6500,9779,10510"; a="369623633" X-IronPort-AV: E=Sophos;i="5.95,210,1661842800"; d="scan'208";a="369623633" Received: from orsmga001.jf.intel.com ([10.7.209.18]) by orsmga104.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 24 Oct 2022 17:44:12 -0700 X-ExtLoop1: 1 X-IronPort-AV: E=McAfee;i="6500,9779,10510"; a="664728638" X-IronPort-AV: E=Sophos;i="5.95,210,1661842800"; d="scan'208";a="664728638" Received: from linux.intel.com ([10.54.29.200]) by orsmga001.jf.intel.com with ESMTP; 24 Oct 2022 17:44:11 -0700 Received: from debox1-desk4.intel.com (unknown [10.209.125.134]) by linux.intel.com (Postfix) with ESMTP id A25FF580D42; Mon, 24 Oct 2022 17:44:11 -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 V7 1/4] PCI/ASPM: Add pci_enable_link_state() Date: Mon, 24 Oct 2022 17:44:08 -0700 Message-Id: <20221025004411.2910026-2-david.e.box@linux.intel.com> X-Mailer: git-send-email 2.25.1 In-Reply-To: <20221025004411.2910026-1-david.e.box@linux.intel.com> References: <20221025004411.2910026-1-david.e.box@linux.intel.com> MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Type: text/plain; charset="utf-8" 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 --- 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 =20 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); =20 +/** + * 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 =3D 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 =3D 0; + if (state & PCIE_LINK_STATE_L0S) + link->aspm_default |=3D ASPM_STATE_L0S; + if (state & PCIE_LINK_STATE_L1) + /* L1 PM substates require L1 */ + link->aspm_default |=3D ASPM_STATE_L1 | ASPM_STATE_L1SS; + if (state & PCIE_LINK_STATE_L1_1) + link->aspm_default |=3D ASPM_STATE_L1_1; + if (state & PCIE_LINK_STATE_L1_2) + link->aspm_default |=3D ASPM_STATE_L1_2; + if (state & PCIE_LINK_STATE_L1_1_PCIPM) + link->aspm_default |=3D ASPM_STATE_L1_1_PCIPM; + if (state & PCIE_LINK_STATE_L1_2_PCIPM) + link->aspm_default |=3D ASPM_STATE_L1_2_PCIPM; + pcie_config_aspm_link(link, policy_to_aspm_state(link)); + + link->clkpm_default =3D (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) =20 #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_d= ev *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;= } --=20 2.25.1