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 1B27FCD4851 for ; Thu, 14 May 2026 17:10:27 +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:In-Reply-To:Content-Type: MIME-Version:References:Message-ID:Subject:Cc:To:From:Date:Reply-To: Content-Transfer-Encoding:Content-ID:Content-Description:Resent-Date: Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:List-Owner; bh=t6NBCCHPcRlz/X1sbSdp5SPdTzKxR1F4eIZOxXUh7u4=; b=2mi7KLh/g23Vux5ISxnA27HbYb S8/0vv9oftjQYALci8E1xIoQ/YupqSCEN5Be7o3A8JuHoL+AOltaFvviIMpxs9Lgkhe8jDc5U/8BX ERIqUWE6FOsbDUTrtm53QH5Pp1IC/MrgNLEWzFXBhoPI7mUmEflzoIy0o4IT00EzEJoN/xquE+h/y Xuyvf6w2I5iBtPRN7Tq6H1/UMygVMq6c1nvvtOL/Mf2DhPfnylfyeygX5HDC2b2vOlUhMyAq9/+QO QY81OGi2BFkYmFUAb/qUkWuWt3m9rtjqygD44cix7bCyrCX5C2AnwXuICzCIIYd1AddQr+0aNpgTr VjtBi40w==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.99.1 #2 (Red Hat Linux)) id 1wNZZk-00000006AGH-42WQ; Thu, 14 May 2026 17:10:20 +0000 Received: from foss.arm.com ([217.140.110.172]) by bombadil.infradead.org with esmtp (Exim 4.99.1 #2 (Red Hat Linux)) id 1wNZZi-00000006AFA-3Hld for linux-arm-kernel@lists.infradead.org; Thu, 14 May 2026 17:10:19 +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 A320D25DE; Thu, 14 May 2026 10:10:11 -0700 (PDT) Received: from arm.com (usa-sjc-mx-foss1.foss.arm.com [172.31.20.19]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id DC6C63F836; Thu, 14 May 2026 10:10:13 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=simple/simple; d=arm.com; s=foss; t=1778778616; bh=QIcPCYJhXPs7IX6f0RotHqQm1SVDBkwqA4iJRWyzoSw=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=rylaXg6T4uAIfiR56zy6O5kwO5eSAcqXi3RA1utMgYam8saAff4YcZFSiSdBoDE6j JHybvRSTp8NUjMkGcHL6uOPDNxE4hjMiszHM7uLsJoXHJ7PesrwH8dm53f9Tl1k6tp R2o33YfHX2KIG3I+fGGySHH6BPvrIFNw1WiGhFbY= Date: Thu, 14 May 2026 18:10:09 +0100 From: Catalin Marinas To: "Aneesh Kumar K.V" Cc: Greg KH , Suzuki K Poulose , linux-coco@lists.linux.dev, linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org, Jeremy Linton , Jonathan Cameron , Lorenzo Pieralisi , Mark Rutland , Sudeep Holla , Will Deacon , Steven Price Subject: Re: [PATCH v5 1/3] firmware: smccc: coco: Manage arm-smccc platform device and CCA auxiliary drivers Message-ID: References: <20260514094030.42495-1-aneesh.kumar@kernel.org> <20260514094030.42495-2-aneesh.kumar@kernel.org> <0c88bcee-65b5-4328-87e6-e1c714c3d1ca@arm.com> <2026051420-amusement-drove-73e6@gregkh> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.9.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20260514_101018_862026_EC56BBF1 X-CRM114-Status: GOOD ( 21.33 ) 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 Thu, May 14, 2026 at 08:08:01PM +0530, Aneesh Kumar K.V wrote: > Catalin Marinas writes: > > On Thu, May 14, 2026 at 02:55:48PM +0200, Greg Kroah-Hartman wrote: > >> On Thu, May 14, 2026 at 12:04:13PM +0100, Suzuki K Poulose wrote: > >> > On 14/05/2026 10:40, Aneesh Kumar K.V (Arm) wrote: > >> > > Make the SMCCC driver responsible for registering the arm-smccc platform > >> > > device and after confirming the relevant SMCCC function IDs, create > >> > > the arm_cca_guest auxiliary device. > >> > > > >> > > >> > There are a few changes squashed in to this patch. Please could we > >> > split the patch in the following order ? > >> > > >> > 1. Add platform device for arm-smccc > >> > >> Do not make any more "fake" platform devices please. > >> > >> > 2. Move TRNG to Auxilliary Device - (Even though it is a later patch, move > >> > it before the RSI changes) > >> > >> No, move it to the faux api please. > > > > So should we end up with: > > > > /sys/devices/faux/arm-smccc/ > > smccc_trng/ > > arm-rsi-dev/ > > tsm/tsm0 > > > > /sys/class/tsm/tsm0 > > -> ../../devices/faux/arm-smccc/arm-rsi-dev/tsm/tsm0 > > > > /sys/firmware/cca/ > > realm_guest > > But we need the ability to autoload different TSM backend drivers based > on the support/availability of these SMCCC function-id ranges. faux > device don't support that. It breaks this but can we not have some systemd rule that checks /sys/firmware/cca/realm_guest and modprobes arm_cca_guest? Alternatively, we could do a request_module("arm_cca_guest") if RSI is available when we check it in smccc_devices_init(). Or make it even fancier with a request_module("arm-smccc-service-...") (some ID range while arm-cca-guest.c has a corresponding MODULE_ALIAS() for that SMCCC range. -- Catalin