From patchwork Tue Jan 25 06:30:22 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Patchwork-Submitter: Robert Kiraly X-Patchwork-Id: 12723321 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 AD8A4C433F5 for ; Tue, 25 Jan 2022 06:43:17 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1349087AbiAYGnP (ORCPT ); Tue, 25 Jan 2022 01:43:15 -0500 Received: from box.aukejan.com ([173.82.79.94]:45123 "EHLO box.aukejan.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1355652AbiAYGlH (ORCPT ); Tue, 25 Jan 2022 01:41:07 -0500 X-Greylist: delayed 631 seconds by postgrey-1.27 at vger.kernel.org; Tue, 25 Jan 2022 01:41:04 EST Received: from authenticated-user (box.aukejan.com [173.82.79.94]) (using TLSv1.3 with cipher TLS_AES_128_GCM_SHA256 (128/128 bits)) (No client certificate requested) by box.aukejan.com (Postfix) with ESMTPSA id DE7F75D334; Mon, 24 Jan 2022 22:30:21 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=boldcoder.com; s=mail; t=1643092222; bh=kvafKXzjkn/Bnf3nCC3bA3bKGXSxh/H7lXD2LBSFypA=; h=Subject:References:To:From:Cc:Date:In-Reply-To:From; b=Sa28aqWv3BU/laUhoiXsb/ddDe2usBbgoeeQi3MYnJV9lQ6zdaYNHCOqoRx5lIxPY kcdxMEjwLZhvIeZ/fjez3x625eP9REC2qOK49BLw6MATUaQCQZ43AmFYxeDY/ovXne RCueyPCXhESbH5Zc1+wWL7czGipE9fdSOgUIUqlHKdFYZmYnXn4SR/yW6zDDMw0Wmo BSXIaFwyHUo0/jf450Ej5/Ha22QpNaK8XU1CwTDvZ/NPMkrVQ3hEWvLMWXU2d6JbpM DD3MPSGNOH0cpV5Vs1vg+72sPats+u1m1WGJbxgbJ7UhJCcRim93cFvlmovVSSDRMF +BPbpozAY5hwg== Subject: Patch: Make ACPI subsystem provide CEDT table References: <1b871357-2231-336d-099c-cdccae03f837@boldcoder.com> To: linux-acpi@vger.kernel.org, linux-cxl@vger.kernel.org From: Robert Kiraly Cc: Len Brown , "Rafael J. Wysocki" , Dan Williams X-Forwarded-Message-Id: <1b871357-2231-336d-099c-cdccae03f837@boldcoder.com> Message-ID: <82f254a1-c765-0a87-f017-8c07c8ef07cd@boldcoder.com> Date: Mon, 24 Jan 2022 22:30:22 -0800 MIME-Version: 1.0 In-Reply-To: <1b871357-2231-336d-099c-cdccae03f837@boldcoder.com> Precedence: bulk List-ID: X-Mailing-List: linux-cxl@vger.kernel.org This is a simple ACPI patch. I'm submitting a revised version to linux-acpi per Rafael Wysocki and linux-cxl per Dan Williams. The patch has been moved to the message body and a Signed-off-by tag has been added. Thunderbird has added CRs so "patch -p1 -l" is needed. To address other points: Q. Dan Williams said: Yes, although I don't see much incremental benefit to developers publishing a root only raw table... So, not opposed to the patch, but I want to direct you to the sysfs representation of the CEDT and CFMWS in /sys/bus/cxl/devices... Platform firmware CXL details are modeled as "CXL root" objects in the /sys/bus/cxl device model. A. The patch is being submitted in connection with work on a CXL bridge. The developers would like to express appreciation for the "sysfs" point. They find it useful to be able to do initialization through the table but will look at the "sysfs" approach. Q. Rafael J. Wysocki said: I'm not sure why the #ifdef is needed. A. I reviewed cxl-next and decided to add the #ifdef to ensure that the code would compile regardless of the direction that the codebase takes. ==== start of patch ==== Subject: Make ACPI subsystem provide CEDT table Signed-off-by: Robert Kiraly This is a simple patch to the ACPI subsystem. The patch adds ACPI _SIG_CEDT to table_sigs[] in "drivers/acpi/tables.c". Presently, CXL code isn't able to make use of the CEDT table at the initrd stage. Subsequent to the change, the CEDT table can be used. If a developer plans to use the CEDT table to program the CXL ports, this change is needed. Otherwise, it isn't expected to make a difference. I certify compliance with Developer’s Certificate of Origin 1.1 as listed in: https://www.kernel.org/doc/html/v4.10/process/submitting-patches. html ==== end of patch ==== --- linux-5.16.old/drivers/acpi/tables.c +++ linux-5.16/drivers/acpi/tables.c @@ -500,6 +500,9 @@ ACPI_SIG_WDDT, ACPI_SIG_WDRT, ACPI_SIG_DSDT, ACPI_SIG_FADT, ACPI_SIG_PSDT, ACPI_SIG_RSDT, ACPI_SIG_XSDT, ACPI_SIG_SSDT, ACPI_SIG_IORT, ACPI_SIG_NFIT, ACPI_SIG_HMAT, ACPI_SIG_PPTT, +#ifdef ACPI_SIG_CEDT + ACPI_SIG_CEDT, +#endif ACPI_SIG_NHLT }; #define ACPI_HEADER_SIZE sizeof(struct acpi_table_header)