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=-2.5 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_PASS,USER_AGENT_MUTT autolearn=ham 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 70F6EC282C8 for ; Mon, 28 Jan 2019 18:36:31 +0000 (UTC) Received: from lists.ozlabs.org (lists.ozlabs.org [203.11.71.2]) (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 D2C8820881 for ; Mon, 28 Jan 2019 18:36:30 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org D2C8820881 Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=kernel.crashing.org Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=linuxppc-dev-bounces+linuxppc-dev=archiver.kernel.org@lists.ozlabs.org Received: from lists.ozlabs.org (lists.ozlabs.org [IPv6:2401:3900:2:1::3]) by lists.ozlabs.org (Postfix) with ESMTP id 43pJHc6bB1zDqC6 for ; Tue, 29 Jan 2019 05:36:28 +1100 (AEDT) Received: from ozlabs.org (bilbo.ozlabs.org [IPv6:2401:3900:2:1::2]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (2048 bits) server-digest SHA256) (No client certificate requested) by lists.ozlabs.org (Postfix) with ESMTPS id 43pJDL6125zDqPG for ; Tue, 29 Jan 2019 05:33:38 +1100 (AEDT) Authentication-Results: lists.ozlabs.org; dmarc=none (p=none dis=none) header.from=kernel.crashing.org Received: from ozlabs.org (bilbo.ozlabs.org [IPv6:2401:3900:2:1::2]) by bilbo.ozlabs.org (Postfix) with ESMTP id 43pJDL2bW5z8tQ2 for ; Tue, 29 Jan 2019 05:33:38 +1100 (AEDT) Received: by ozlabs.org (Postfix) id 43pJDL0Wh4z9sMM; Tue, 29 Jan 2019 05:33:38 +1100 (AEDT) Authentication-Results: ozlabs.org; spf=permerror (mailfrom) smtp.mailfrom=kernel.crashing.org (client-ip=63.228.1.57; helo=gate.crashing.org; envelope-from=segher@kernel.crashing.org; receiver=) Authentication-Results: ozlabs.org; dmarc=none (p=none dis=none) header.from=kernel.crashing.org Received: from gate.crashing.org (gate.crashing.org [63.228.1.57]) (using TLSv1 with cipher DHE-RSA-AES256-SHA (256/256 bits)) (No client certificate requested) by ozlabs.org (Postfix) with ESMTPS id 43pJDK07Hpz9sML for ; Tue, 29 Jan 2019 05:33:36 +1100 (AEDT) Received: from gate.crashing.org (localhost.localdomain [127.0.0.1]) by gate.crashing.org (8.14.1/8.14.1) with ESMTP id x0SIWY6Y031778; Mon, 28 Jan 2019 12:32:35 -0600 Received: (from segher@localhost) by gate.crashing.org (8.14.1/8.14.1/Submit) id x0SIWX3H031769; Mon, 28 Jan 2019 12:32:33 -0600 X-Authentication-Warning: gate.crashing.org: segher set sender to segher@kernel.crashing.org using -f Date: Mon, 28 Jan 2019 12:32:32 -0600 From: Segher Boessenkool To: Christophe Leroy Subject: Re: What is CONFIG_RTAS ? Which CPUs are concerned Message-ID: <20190128183231.GP14180@gate.crashing.org> References: Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: User-Agent: Mutt/1.4.2.3i X-BeenThere: linuxppc-dev@lists.ozlabs.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: Linux on PowerPC Developers Mail List List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: "linuxppc-dev@ozlabs.org" , Paul Mackerras , Nicholas Piggin Errors-To: linuxppc-dev-bounces+linuxppc-dev=archiver.kernel.org@lists.ozlabs.org Sender: "Linuxppc-dev" On Mon, Jan 28, 2019 at 07:20:43PM +0100, Christophe Leroy wrote: > I'm wondering what CONFIG_RTAS is. It makes use of one of the SPRN_SPRG, > ie SPRN_SPRG2. > > What are the CPUs concerned by RTAS ? Is there any of the old CPUs which > have only 4 SPRGs (eg the 601), or could we use one in SPRG4-7 for it > and reuse SPRG2 for something else ? RTAS (run-time abstraction services) is as old as PowerPC itself. Yes there is RTAS on various 6xx, and those do not have any SPRGs not defined in the architecture. RTAS is a feature of the firmware, or of the platform you could say. Not a feature of CPUs. Segher