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);