From patchwork Thu Dec 16 05:55:59 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: "David E. Box" X-Patchwork-Id: 12680053 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 2BCF7C433EF for ; Thu, 16 Dec 2021 05:56:08 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S231534AbhLPF4H (ORCPT ); Thu, 16 Dec 2021 00:56:07 -0500 Received: from mga05.intel.com ([192.55.52.43]:1908 "EHLO mga05.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S231509AbhLPF4G (ORCPT ); Thu, 16 Dec 2021 00:56:06 -0500 X-IronPort-AV: E=McAfee;i="6200,9189,10199"; a="325691356" X-IronPort-AV: E=Sophos;i="5.88,210,1635231600"; d="scan'208";a="325691356" Received: from fmsmga008.fm.intel.com ([10.253.24.58]) by fmsmga105.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 15 Dec 2021 21:56:01 -0800 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.88,210,1635231600"; d="scan'208";a="568219972" Received: from linux.intel.com ([10.54.29.200]) by fmsmga008.fm.intel.com with ESMTP; 15 Dec 2021 21:56:01 -0800 Received: from debox1-desk4.intel.com (unknown [10.209.86.221]) by linux.intel.com (Postfix) with ESMTP id AA555580D42; Wed, 15 Dec 2021 21:56:00 -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 V4 1/2] PCI/ASPM: Add ASPM BIOS override function Date: Wed, 15 Dec 2021 21:55:59 -0800 Message-Id: <20211216055600.2425362-1-david.e.box@linux.intel.com> X-Mailer: git-send-email 2.25.1 MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: linux-pci@vger.kernel.org From: Michael Bottini Devices that appear under the Intel VMD host bridge are not visible to BIOS and therefore not programmed by BIOS with ASPM settings. For these devices, it is necessary for the driver to configure ASPM. Since ASPM settings are adjustable at runtime by module parameter, use the same mechanism to allow drivers to override the default (in this case never configured) BIOS policy to ASPM_STATE_ALL. Then, reconfigure ASPM on the link. Do not override if ASPM control is disabled. Signed-off-by: Michael Bottini Signed-off-by: David E. Box --- V4 - No changes. V3 - Fix missing semicolon in static inline function. V2 - Change return type to int so caller can determine if override was successful. - Return immediately if link is not found so that lock it not unecessarily taken, suggested by kw@linux.com. - Don't override if aspm_disabled is true. drivers/pci/pci.h | 2 ++ drivers/pci/pcie/aspm.c | 19 +++++++++++++++++++ 2 files changed, 21 insertions(+) diff --git a/drivers/pci/pci.h b/drivers/pci/pci.h index 3d60cabde1a1..c9c55d43cd8a 100644 --- a/drivers/pci/pci.h +++ b/drivers/pci/pci.h @@ -562,11 +562,13 @@ void pcie_aspm_init_link_state(struct pci_dev *pdev); void pcie_aspm_exit_link_state(struct pci_dev *pdev); void pcie_aspm_pm_state_change(struct pci_dev *pdev); void pcie_aspm_powersave_config_link(struct pci_dev *pdev); +int pcie_aspm_policy_override(struct pci_dev *dev); #else static inline void pcie_aspm_init_link_state(struct pci_dev *pdev) { } static inline void pcie_aspm_exit_link_state(struct pci_dev *pdev) { } static inline void pcie_aspm_pm_state_change(struct pci_dev *pdev) { } static inline void pcie_aspm_powersave_config_link(struct pci_dev *pdev) { } +static inline int pcie_aspm_policy_override(struct pci_dev *dev) { return -EINVAL; } #endif #ifdef CONFIG_PCIE_ECRC diff --git a/drivers/pci/pcie/aspm.c b/drivers/pci/pcie/aspm.c index 52c74682601a..e2c61e14e724 100644 --- a/drivers/pci/pcie/aspm.c +++ b/drivers/pci/pcie/aspm.c @@ -1140,6 +1140,25 @@ int pci_disable_link_state(struct pci_dev *pdev, int state) } EXPORT_SYMBOL(pci_disable_link_state); +int pcie_aspm_policy_override(struct pci_dev *pdev) +{ + struct pcie_link_state *link = pcie_aspm_get_link(pdev); + + if (!link || aspm_disabled) + return -EINVAL; + + down_read(&pci_bus_sem); + mutex_lock(&aspm_lock); + link->aspm_default = ASPM_STATE_ALL; + pcie_config_aspm_link(link, policy_to_aspm_state(link)); + pcie_set_clkpm(link, policy_to_clkpm_state(link)); + mutex_unlock(&aspm_lock); + up_read(&pci_bus_sem); + + return 0; +} +EXPORT_SYMBOL(pcie_aspm_policy_override); + static int pcie_aspm_set_policy(const char *val, const struct kernel_param *kp) { From patchwork Thu Dec 16 05:56:00 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: "David E. Box" X-Patchwork-Id: 12680051 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 F3F11C433F5 for ; Thu, 16 Dec 2021 05:56:04 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S231343AbhLPF4D (ORCPT ); Thu, 16 Dec 2021 00:56:03 -0500 Received: from mga09.intel.com ([134.134.136.24]:22987 "EHLO mga09.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S230525AbhLPF4C (ORCPT ); Thu, 16 Dec 2021 00:56:02 -0500 X-IronPort-AV: E=McAfee;i="6200,9189,10199"; a="239222632" X-IronPort-AV: E=Sophos;i="5.88,210,1635231600"; d="scan'208";a="239222632" Received: from fmsmga005.fm.intel.com ([10.253.24.32]) by orsmga102.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 15 Dec 2021 21:56:02 -0800 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.88,210,1635231600"; d="scan'208";a="755714722" Received: from linux.intel.com ([10.54.29.200]) by fmsmga005.fm.intel.com with ESMTP; 15 Dec 2021 21:56:01 -0800 Received: from debox1-desk4.intel.com (unknown [10.209.86.221]) by linux.intel.com (Postfix) with ESMTP id 08AC0580514; Wed, 15 Dec 2021 21:56:01 -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 V4 2/2] PCI: vmd: Override ASPM on TGL/ADL VMD devices Date: Wed, 15 Dec 2021 21:56:00 -0800 Message-Id: <20211216055600.2425362-2-david.e.box@linux.intel.com> X-Mailer: git-send-email 2.25.1 In-Reply-To: <20211216055600.2425362-1-david.e.box@linux.intel.com> References: <20211216055600.2425362-1-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 On Tiger Lake and Alder Lake platforms, VMD controllers do not have ASPM enabled nor LTR values set by BIOS. This leads high power consumption on these platforms when VMD is enabled as reported in bugzilla [1]. Enable these features in the VMD driver using pcie_aspm_policy_override() to set the ASPM policy for the root ports. To do this, add an additional flag in VMD features to specify devices that must have their respective policies overridden. [1] https://bugzilla.kernel.org/show_bug.cgi?id=213717 Signed-off-by: Michael Bottini Signed-off-by: David E. Box Tested-by: Adhitya Mohan --- 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/controller/vmd.c | 43 +++++++++++++++++++++++++++++++++--- 1 file changed, 40 insertions(+), 3 deletions(-) diff --git a/drivers/pci/controller/vmd.c b/drivers/pci/controller/vmd.c index a45e8e59d3d4..880afd450a14 100644 --- a/drivers/pci/controller/vmd.c +++ b/drivers/pci/controller/vmd.c @@ -20,6 +20,8 @@ #include +#include "../pci.h" + #define VMD_CFGBAR 0 #define VMD_MEMBAR1 2 #define VMD_MEMBAR2 4 @@ -67,6 +69,12 @@ enum vmd_features { * interrupt handling. */ VMD_FEAT_CAN_BYPASS_MSI_REMAP = (1 << 4), + + /* + * Device must have ASPM policy overridden, as its default policy is + * incorrect. + */ + VMD_FEAT_QUIRK_OVERRIDE_ASPM = (1 << 5), }; static DEFINE_IDA(vmd_instance_ida); @@ -661,6 +669,30 @@ static int vmd_alloc_irqs(struct vmd_dev *vmd) return 0; } +/* + * Override the BIOS ASPM policy and set the LTR value for PCI storage + * devices on the VMD bride. + */ +static int vmd_enable_aspm(struct pci_dev *pdev, void *userdata) +{ + int features = *(int *)userdata, pos; + + if (!(features & VMD_FEAT_QUIRK_OVERRIDE_ASPM) || + pdev->class != PCI_CLASS_STORAGE_EXPRESS) + return 0; + + pos = pci_find_ext_capability(pdev, PCI_EXT_CAP_ID_LTR); + if (!pos) + return 0; + + pci_write_config_word(pdev, pos + PCI_LTR_MAX_SNOOP_LAT, 0x1003); + pci_write_config_word(pdev, pos + PCI_LTR_MAX_NOSNOOP_LAT, 0x1003); + if (pcie_aspm_policy_override(pdev)) + pci_info(pdev, "Unable of override ASPM policy\n"); + + return 0; +} + static int vmd_enable_domain(struct vmd_dev *vmd, unsigned long features) { struct pci_sysdata *sd = &vmd->sysdata; @@ -807,6 +839,8 @@ static int vmd_enable_domain(struct vmd_dev *vmd, unsigned long features) pci_scan_child_bus(vmd->bus); pci_assign_unassigned_bus_resources(vmd->bus); + pci_walk_bus(vmd->bus, vmd_enable_aspm, &features); + /* * VMD root buses are virtual and don't return true on pci_is_pcie() * and will fail pcie_bus_configure_settings() early. It can instead be @@ -948,15 +982,18 @@ static const struct pci_device_id vmd_ids[] = { {PCI_DEVICE(PCI_VENDOR_ID_INTEL, 0x467f), .driver_data = VMD_FEAT_HAS_MEMBAR_SHADOW_VSCAP | VMD_FEAT_HAS_BUS_RESTRICTIONS | - VMD_FEAT_OFFSET_FIRST_VECTOR,}, + VMD_FEAT_OFFSET_FIRST_VECTOR | + VMD_FEAT_QUIRK_OVERRIDE_ASPM,}, {PCI_DEVICE(PCI_VENDOR_ID_INTEL, 0x4c3d), .driver_data = VMD_FEAT_HAS_MEMBAR_SHADOW_VSCAP | VMD_FEAT_HAS_BUS_RESTRICTIONS | - VMD_FEAT_OFFSET_FIRST_VECTOR,}, + VMD_FEAT_OFFSET_FIRST_VECTOR | + VMD_FEAT_QUIRK_OVERRIDE_ASPM,}, {PCI_DEVICE(PCI_VENDOR_ID_INTEL, PCI_DEVICE_ID_INTEL_VMD_9A0B), .driver_data = VMD_FEAT_HAS_MEMBAR_SHADOW_VSCAP | VMD_FEAT_HAS_BUS_RESTRICTIONS | - VMD_FEAT_OFFSET_FIRST_VECTOR,}, + VMD_FEAT_OFFSET_FIRST_VECTOR | + VMD_FEAT_QUIRK_OVERRIDE_ASPM,}, {0,} }; MODULE_DEVICE_TABLE(pci, vmd_ids);