From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-2.3 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_HELO_NONE, SPF_PASS,URIBL_BLOCKED,USER_AGENT_SANE_1 autolearn=no autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 2CF3AC2BB86 for ; Tue, 14 Apr 2020 10:54:38 +0000 (UTC) Received: from bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id EF5E9206D5 for ; Tue, 14 Apr 2020 10:54:37 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=lists.infradead.org header.i=@lists.infradead.org header.b="l6U7ajXZ" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org EF5E9206D5 Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=arm.com Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-arm-kernel-bounces+infradead-linux-arm-kernel=archiver.kernel.org@lists.infradead.org DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20170209; h=Sender: Content-Transfer-Encoding:Content-Type:Cc:List-Subscribe:List-Help:List-Post: List-Archive:List-Unsubscribe:List-Id:In-Reply-To:MIME-Version:References: Message-ID:Subject:To:From:Date:Reply-To:Content-ID:Content-Description: Resent-Date:Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID: List-Owner; bh=e1R5KhSR7VTlBQ7XhVwoqOEWjU3Lq7XJosf3H5ZD4w4=; b=l6U7ajXZ6k8BAR a8x6f7yLde1BCX0labKFZe7volnkr1oowKz3bhTXgQs0zDaeWlcCWOpqTKso8+HSJ9cyeufUBxKr0 Z8vRrJlCeNr/1ouSQIgUWN0DtThyM1RCeSxTKvMDDvah7oWr0PnEW9q980FzwW4UNZnODMhfdfWzU +OkSZdypS6FZZskGZanlSfOL/S0SRIwemQwTTXe4c5+h2WMyUgiSEIpxMqg4GaP15P5L455kLNarq bBx9O1XPTpZoz8ZzGdXHZkQo4Pop20OnZGpXmi8CSXq9RmIDM/PTmisGLq0KK2PYCPIPhVEI97rpJ xCIFL19nKsLMmDk0Cidw==; Received: from localhost ([127.0.0.1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.92.3 #3 (Red Hat Linux)) id 1jOJDA-0000yY-H4; Tue, 14 Apr 2020 10:54:36 +0000 Received: from foss.arm.com ([217.140.110.172]) by bombadil.infradead.org with esmtp (Exim 4.92.3 #3 (Red Hat Linux)) id 1jOJD6-0000ue-4G for linux-arm-kernel@lists.infradead.org; Tue, 14 Apr 2020 10:54:33 +0000 Received: from usa-sjc-imap-foss1.foss.arm.com (unknown [10.121.207.14]) by usa-sjc-mx-foss1.foss.arm.com (Postfix) with ESMTP id 6CEFE1FB; Tue, 14 Apr 2020 03:54:29 -0700 (PDT) Received: from bogus (unknown [10.37.12.71]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id 5FF9A3F6C4; Tue, 14 Apr 2020 03:54:27 -0700 (PDT) Date: Tue, 14 Apr 2020 11:54:24 +0100 From: Sudeep Holla To: Hanjun Guo Subject: Re: ACPI support for System Control and Management Interface (SCMI) Message-ID: <20200414105424.GB17835@bogus> References: <52a50069-7140-b9b4-31b4-8c99e8c0d991@huawei.com> MIME-Version: 1.0 Content-Disposition: inline In-Reply-To: <52a50069-7140-b9b4-31b4-8c99e8c0d991@huawei.com> User-Agent: Mutt/1.9.4 (2018-02-28) X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20200414_035432_222841_01B37025 X-CRM114-Status: GOOD ( 12.33 ) X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: 'Thanu Rangarajan' , Sudeep Holla , souvik.chakravarty@arm.com, John Garry , Linuxarm , Shameerali Kolothum Thodi , Matteo Carlini , Jonathan Cameron , linux-arm-kernel@lists.infradead.org, Charles Garcia-Tobin Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+infradead-linux-arm-kernel=archiver.kernel.org@lists.infradead.org On Fri, Apr 10, 2020 at 10:26:41AM +0800, Hanjun Guo wrote: > Hi Sudeep, > > We are working on the enablement of SCMI for Kunepeng920, > which is a server chip using ACPI, but I didn't see the > ACPI support in the mainline kernel for SCMI. > > Kunpeng920 and the upcomming Kunpeng930 have thermal > sensors and other system management features which > needs the SCMI for abstraction layer, do we have plan > to support ACPI for SCMI? > Yes and No. Yes, because the same SCMI compliant firmware needs to work with ACPI as SCMI is designed so. No, because we don't plan to add another SCMI layer below ACPI in the kernel. ACPI specification was extended to support special PCC types to support the same. IIUC things like sensors are supported using power meter objects in ACPI and you must be able to use PCC opregion for it or any custom mechanism to achieve that. However one need to add PCC opregion handler in Linux. The main idea is you must use existing ACPI methods and we don't plan to add anything special for SCMI. SCMI Perf protocol is compatible with CPPC. We can discuss details once you explore PCC opregion or any alternative you come up with. I am no ACPI firmware expert and I reckon you may have other interesting ideas. -- Regards, Sudeep _______________________________________________ linux-arm-kernel mailing list linux-arm-kernel@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-arm-kernel