From patchwork Mon Feb 6 20:50:42 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Dave Jiang X-Patchwork-Id: 13130601 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 A7EA0C636D3 for ; Mon, 6 Feb 2023 20:50:48 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S230340AbjBFUur (ORCPT ); Mon, 6 Feb 2023 15:50:47 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:48514 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S230354AbjBFUur (ORCPT ); Mon, 6 Feb 2023 15:50:47 -0500 Received: from mga07.intel.com (mga07.intel.com [134.134.136.100]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 517D22B097; Mon, 6 Feb 2023 12:50:46 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=intel.com; i=@intel.com; q=dns/txt; s=Intel; t=1675716646; x=1707252646; h=subject:from:to:cc:date:message-id:in-reply-to: references:mime-version:content-transfer-encoding; bh=8IOW1adM9oC2jAAA+J+4B+32FWUmU6UHY5MmsRIO4bg=; b=dEfTOyVJ/0Gw2ooe/ex5AwWYrBd7xc6f5eMuTR+9sftlfWEjfjYkH7cy g8G7wEH49kkUUB7IUbfW0lLXjX8OsQzJJJd05UdLY2LaQ+uCU31R189Dk 7ZA7kbSkcnVc6hB29h9OTrMP/duuwqf/1VMaeQiKJX4M4lkbHXRHxDauH Ve5GupE0qghcO32TlVo/E+LlzlCjr0hcaxm1v0vU5XN4XhPsGB6zoqgMd fPjTs6fk5XUtwqdJybS2GyAAcpsYT0EWVBbHGTLIAya975IXkJCP7jCX7 JQdpK0ZIAnREYhQhcWlntDlPVN5ooJIpzWRLyEKx5ssiq9joi0AO23Erw g==; X-IronPort-AV: E=McAfee;i="6500,9779,10613"; a="393912042" X-IronPort-AV: E=Sophos;i="5.97,276,1669104000"; d="scan'208";a="393912042" Received: from orsmga003.jf.intel.com ([10.7.209.27]) by orsmga105.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 06 Feb 2023 12:50:45 -0800 X-IronPort-AV: E=McAfee;i="6500,9779,10613"; a="616559702" X-IronPort-AV: E=Sophos;i="5.97,276,1669104000"; d="scan'208";a="616559702" Received: from djiang5-mobl3.amr.corp.intel.com (HELO djiang5-mobl3.local) ([10.212.111.195]) by orsmga003-auth.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 06 Feb 2023 12:50:44 -0800 Subject: [PATCH 09/18] cxl: Add helper function to retrieve ACPI handle of CXL root device From: Dave Jiang To: linux-cxl@vger.kernel.org, linux-pci@vger.kernel.org, linux-acpi@vger.kernel.org Cc: dan.j.williams@intel.com, ira.weiny@intel.com, vishal.l.verma@intel.com, alison.schofield@intel.com, rafael@kernel.org, bhelgaas@google.com, robert.moore@intel.com Date: Mon, 06 Feb 2023 13:50:42 -0700 Message-ID: <167571664152.587790.608196538260467034.stgit@djiang5-mobl3.local> In-Reply-To: <167571650007.587790.10040913293130712882.stgit@djiang5-mobl3.local> References: <167571650007.587790.10040913293130712882.stgit@djiang5-mobl3.local> User-Agent: StGit/1.5 MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: linux-cxl@vger.kernel.org Provide a helper to find the ACPI0017 device in order to issue the _DSM. The helper will take the 'struct device' from a cxl_port and iterate until the root device is reached. The ACPI handle will be returned from the root device. Signed-off-by: Dave Jiang --- drivers/cxl/core/acpi.c | 30 ++++++++++++++++++++++++++++++ drivers/cxl/cxl.h | 1 + 2 files changed, 31 insertions(+) diff --git a/drivers/cxl/core/acpi.c b/drivers/cxl/core/acpi.c index 86dc6c9c1f24..05fcd4751619 100644 --- a/drivers/cxl/core/acpi.c +++ b/drivers/cxl/core/acpi.c @@ -5,6 +5,7 @@ #include #include #include +#include #include #include "cxlpci.h" #include "cxl.h" @@ -13,6 +14,35 @@ const guid_t acpi_cxl_qtg_id_guid = GUID_INIT(0xF365F9A6, 0xA7DE, 0x4071, 0xA6, 0x6A, 0xB4, 0x0C, 0x0B, 0x4F, 0x8E, 0x52); +/** + * cxl_acpi_get_root_acpi_handle - get the ACPI handle of the CXL root device + * @dev: 'struct device' to start searching from. Should be from cxl_port->dev. + * Looks for the ACPI0017 device and return the ACPI handle + **/ +acpi_handle cxl_acpi_get_rootdev_handle(struct device *dev) +{ + struct device *itr = dev, *root_dev; + acpi_handle handle; + + if (!dev) + return ERR_PTR(-EINVAL); + + while (itr->parent) { + root_dev = itr; + itr = itr->parent; + } + + if (!dev_is_platform(root_dev)) + return ERR_PTR(-ENODEV); + + handle = ACPI_HANDLE(root_dev); + if (!handle) + return ERR_PTR(-ENODEV); + + return handle; +} +EXPORT_SYMBOL_NS_GPL(cxl_acpi_get_rootdev_handle, CXL); + /** * cxl_acpi_evaluate_qtg_dsm - Retrieve QTG ids via ACPI _DSM * @handle: ACPI handle diff --git a/drivers/cxl/cxl.h b/drivers/cxl/cxl.h index e70df07f9b4b..ac6ea550ab0a 100644 --- a/drivers/cxl/cxl.h +++ b/drivers/cxl/cxl.h @@ -733,6 +733,7 @@ struct qtg_dsm_output { struct qtg_dsm_output *cxl_acpi_evaluate_qtg_dsm(acpi_handle handle, struct qtg_dsm_input *input); +acpi_handle cxl_acpi_get_rootdev_handle(struct device *dev); /* * Unit test builds overrides this to __weak, find the 'strong' version