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 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 smtp.lore.kernel.org (Postfix) with ESMTPS id 03C8CFA3755 for ; Fri, 13 Sep 2024 13:54:07 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20210309; h=Sender:List-Subscribe:List-Help :List-Post:List-Archive:List-Unsubscribe:List-Id:Content-Transfer-Encoding: Content-Type:In-Reply-To:From:References:Cc:To:Subject:MIME-Version:Date: Message-ID:Reply-To:Content-ID:Content-Description:Resent-Date:Resent-From: Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:List-Owner; bh=IPB1vZQOM6NE+VteZM0VBpTVmq0DDlUtUW54JuF6eDg=; b=YEiJyisd4PyoGV1g9WBuO12f2X 3kH8yoMpKs4Ya6Eky3UJfRo4Nn38+j6S8F6ZwcowKwdxa0IdWsRT+hJsZYIpq+q7nKevomxPuVhDB Rf4r3J99mMWh4CkvGBEkOQXuyAmh9NUlWyRSvLnfyHVFBsHyMleEzQuHKMOREqgZGrDYPO0PrVCEN 0P2xhDQ5r0XZ1CPNZQKtP82bxwXhGlcBwruYL88s24z+xINSil6cP96kKE+e689LJVkcBWF3EZf+f NYGbRGTlmEQ3UNIpOFFBCgKZ1itOt970a+4KSIanJJJjQz0Pv8q+BVoewfW6Y3aJtBTEYx/BTjcU6 iqLvIaBA==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.97.1 #2 (Red Hat Linux)) id 1sp6kD-0000000G6Iz-41mu; Fri, 13 Sep 2024 13:53:54 +0000 Received: from foss.arm.com ([217.140.110.172]) by bombadil.infradead.org with esmtp (Exim 4.97.1 #2 (Red Hat Linux)) id 1sp6j8-0000000G69N-1xR8 for linux-arm-kernel@lists.infradead.org; Fri, 13 Sep 2024 13:52:49 +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 1106A13D5; Fri, 13 Sep 2024 06:53:13 -0700 (PDT) Received: from [10.1.197.1] (ewhatever.cambridge.arm.com [10.1.197.1]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id 16F153F73B; Fri, 13 Sep 2024 06:52:40 -0700 (PDT) Message-ID: <2f9f10cf-7356-458a-bf63-ed6a757df81f@arm.com> Date: Fri, 13 Sep 2024 14:52:39 +0100 MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: [PATCH v5 04/19] firmware/psci: Add psci_early_test_conduit() To: Catalin Marinas , Steven Price Cc: kvm@vger.kernel.org, kvmarm@lists.linux.dev, Marc Zyngier , Will Deacon , James Morse , Oliver Upton , Zenghui Yu , linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org, Joey Gouly , Alexandru Elisei , Christoffer Dall , Fuad Tabba , linux-coco@lists.linux.dev, Ganapatrao Kulkarni , Gavin Shan , Shanker Donthineni , Alper Gun , Jean-Philippe Brucker References: <20240819131924.372366-1-steven.price@arm.com> <20240819131924.372366-5-steven.price@arm.com> Content-Language: en-US From: Suzuki K Poulose In-Reply-To: Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20240913_065246_584841_58F2B693 X-CRM114-Status: GOOD ( 15.11 ) X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.34 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+linux-arm-kernel=archiver.kernel.org@lists.infradead.org On 26/08/2024 11:03, Catalin Marinas wrote: > On Mon, Aug 19, 2024 at 02:19:09PM +0100, Steven Price wrote: >> From: Jean-Philippe Brucker >> >> Add a function to test early if PSCI is present and what conduit it >> uses. Because the PSCI conduit corresponds to the SMCCC one, this will >> let the kernel know whether it can use SMC instructions to discuss with >> the Realm Management Monitor (RMM), early enough to enable RAM and >> serial access when running in a Realm. >> >> Signed-off-by: Jean-Philippe Brucker >> Signed-off-by: Steven Price > > On the code itself: > > Reviewed-by: Catalin Marinas > > However, Will has a point and it would be good if we can avoid this > early setup as much as possible. If it's just the early console used for > debugging, maybe just pass the full IPA address on the command line and > allow those high addresses in fixmap. Not sure about the EFI map. > We could delay the RSI init until we have probed the PSCI conduit. This could be done from setup_arch(), after the psci_{dt,acpi}_init(). This is safe, as the EFI maps are only created later, as an early_initcall(). Kind regards Suzuki