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,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 68A58C43603 for ; Thu, 12 Dec 2019 14:44:12 +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 38BEB21655 for ; Thu, 12 Dec 2019 14:44:12 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=lists.infradead.org header.i=@lists.infradead.org header.b="Xicn90WG" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 38BEB21655 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=s7XcKtTgFcSi2liMO7V6EwVAJVCj+FoCTFjbekuGwAI=; b=Xicn90WGA+mNSN +vKdw+xHtqRUG8v70EFtUVR2vQdV71M3SzfKPlYpSeXp5qh3pxPYcMshzaQ2mrCQlRvbOPlwnPJAz j46PxzdzfcpjYpsazl4w7GNesxfQYapag1nswyB2tX9oVuBl/H4FNITVAGu5TS1Vbv7tAyAbextrU yrfvt4rU4Nsu2qziKk+TcxW6hWxLULcrJskIP7CyH6QdwxRcy1/tW+D9TIkhYtyvQ42NkZafkbyQ/ 7P6NAJRrBxpKxL/1gH9dIPKRejwJ+y0oBoO3SaB1P+WUqjF2am8WAl0Df/foI4/E04VrYNYOI9aP9 t9LD2hdrCfr+ypDyT/TQ==; 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 1ifPhH-00084A-5O; Thu, 12 Dec 2019 14:44:07 +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 1ifPhD-00083P-Vh; Thu, 12 Dec 2019 14:44:05 +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 4B0E530E; Thu, 12 Dec 2019 06:44:03 -0800 (PST) Received: from bogus (e107155-lin.cambridge.arm.com [10.1.196.42]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id D90EA3F718; Thu, 12 Dec 2019 06:44:00 -0800 (PST) Date: Thu, 12 Dec 2019 14:43:55 +0000 From: Sudeep Holla To: Ard Biesheuvel Subject: Re: [PATCH v5 3/3] hwrng: add mtk-sec-rng driver Message-ID: <20191212144355.GA13263@bogus> References: <1574864578-467-1-git-send-email-neal.liu@mediatek.com> <1574864578-467-4-git-send-email-neal.liu@mediatek.com> <1575027046.24848.4.camel@mtkswgap22> MIME-Version: 1.0 Content-Disposition: inline In-Reply-To: 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-20191212_064404_110337_825483FF X-CRM114-Status: GOOD ( 20.86 ) 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: Mark Rutland , DTML , Sudeep Holla , Herbert Xu , wsd_upstream , Catalin Marinas , Matt Mackall , Sean Wang , "linux-mediatek@lists.infradead.org" , Linux Kernel Mailing List , Rob Herring , Neal Liu , "linux-crypto@vger.kernel.org" , Marc Zyngier , Matthias Brugger , Crystal Guo =?utf-8?B?KOmDreaZtik=?= , Will Deacon , Lars Persson , "linux-arm-kernel@lists.infradead.org" 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 Mon, Dec 02, 2019 at 04:12:09PM +0000, Ard Biesheuvel wrote: > (adding some more arm64 folks) > > On Fri, 29 Nov 2019 at 11:30, Neal Liu wrote: > > > > On Fri, 2019-11-29 at 18:02 +0800, Lars Persson wrote: > > > Hi Neal, > > > > > > On Wed, Nov 27, 2019 at 3:23 PM Neal Liu wrote: > > > > > > > > For MediaTek SoCs on ARMv8 with TrustZone enabled, peripherals like > > > > entropy sources is not accessible from normal world (linux) and > > > > rather accessible from secure world (ATF/TEE) only. This driver aims > > > > to provide a generic interface to ATF rng service. > > > > > > > > > > I am working on several SoCs that also will need this kind of driver > > > to get entropy from Arm trusted firmware. > > > If you intend to make this a generic interface, please clean up the > > > references to MediaTek and give it a more generic name. For example > > > "Arm Trusted Firmware random number driver". > > > > > > It will also be helpful if the SMC call number is configurable. > > > > > > - Lars > > > > Yes, I'm trying to make this to a generic interface. I'll try to make > > HW/platform related dependency to be configurable and let it more > > generic. > > Thanks for your suggestion. > > > > I don't think it makes sense for each arm64 platform to expose an > entropy source via SMC calls in a slightly different way, and model it > as a h/w driver. Instead, we should try to standardize this, and > perhaps expose it via the architectural helpers that already exist > (get_random_seed_long() and friends), so they get plugged into the > kernel random pool driver directly. > > Note that in addition to drivers based on vendor SMC calls, we already > have a RNG h/w driver based on OP-TEE as well, where the driver > attaches to a standardized trusted OS interface identified by a UUID, > and which also gets invoked via SMC calls into secure firmware. Yes, I agree. I had raised the issue internally and forgot to follow up. I raised this few months back after I read a blog[1] -- Regards, Sudeep [1] https://community.arm.com/developer/ip-products/processors/f/cortex-a-forum/43679/arm-really-should-standardize-an-smc-interface-for-hardware-random-number-generators _______________________________________________ linux-arm-kernel mailing list linux-arm-kernel@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-arm-kernel