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=-1.1 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS 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 31A99C433E0 for ; Wed, 3 Jun 2020 11:12:09 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 097CA20738 for ; Wed, 3 Jun 2020 11:12:09 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1591182729; bh=YzOMemc162MmX21grMM2woz3galEvoPugqrE5a3TFD8=; h=Date:From:To:Cc:Subject:In-Reply-To:References:List-ID:From; b=yUyLT/LePs4AvLUtR4EAsTzCawtzeAKA6i09PtqDznLnoJFpHHqu/qCfn/WVqL7yl 1GpjA88sRW5p9lV8G3nLSXemosbreG1Sp/SNr8rvFXim3PQydGUVC1dHR+Qz3v+stP M+q+I/zUjt+OmrF6Xn8GcjhkXwnX6x8ukg668NWg= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1725917AbgFCLMI (ORCPT ); Wed, 3 Jun 2020 07:12:08 -0400 Received: from mail.kernel.org ([198.145.29.99]:57514 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1725833AbgFCLMI (ORCPT ); Wed, 3 Jun 2020 07:12:08 -0400 Received: from disco-boy.misterjones.org (disco-boy.misterjones.org [51.254.78.96]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id 57EA8206C3; Wed, 3 Jun 2020 11:12:07 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1591182727; bh=YzOMemc162MmX21grMM2woz3galEvoPugqrE5a3TFD8=; h=Date:From:To:Cc:Subject:In-Reply-To:References:From; b=VCecdmeYHrqT5gcinE0svjjnWovDvj6uzuTznngJAf93O0LV5n1J9DoWLJtEk9vv6 0JAbXLvW79Wb3/N+75QFT30BcC7kfKT3VMjSG/UnSS7QAUN3pVQpc6LlZXKzk03LyZ ZetdVU8f9I1Kxws4imoEVWR93RtBzxSkFBKnQEO4= Received: from disco-boy.misterjones.org ([51.254.78.96] helo=www.loen.fr) by disco-boy.misterjones.org with esmtpsa (TLS1.2:ECDHE_RSA_AES_128_GCM_SHA256:128) (Exim 4.92) (envelope-from ) id 1jgRJV-00HQNN-OT; Wed, 03 Jun 2020 12:12:05 +0100 MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII; format=flowed Content-Transfer-Encoding: 7bit Date: Wed, 03 Jun 2020 12:12:05 +0100 From: Marc Zyngier To: Neal Liu Cc: Julius Werner , Ard Biesheuvel , "open list:OPEN FIRMWARE AND FLATTENED DEVICE TREE BINDINGS" , Herbert Xu , Arnd Bergmann , Greg Kroah-Hartman , Sean Wang , linux-mediatek@lists.infradead.org, lkml , wsd_upstream , Rob Herring , Linux Crypto Mailing List , Matt Mackall , Matthias Brugger , =?UTF-8?Q?Crystal_Guo_=28=E9=83=AD?= =?UTF-8?Q?=E6=99=B6=29?= , Linux ARM , mark.rutland@arm.com, Jose.Marinho@arm.com Subject: Re: Security Random Number Generator support In-Reply-To: <1591170857.19414.5.camel@mtkswgap22> References: <1591085678-22764-1-git-send-email-neal.liu@mediatek.com> <85dfc0142d3879d50c0ba18bcc71e199@misterjones.org> <1591169342.4878.9.camel@mtkswgap22> <1591170857.19414.5.camel@mtkswgap22> User-Agent: Roundcube Webmail/1.4.4 Message-ID: X-Sender: maz@kernel.org X-SA-Exim-Connect-IP: 51.254.78.96 X-SA-Exim-Rcpt-To: neal.liu@mediatek.com, jwerner@google.com, ardb@kernel.org, devicetree@vger.kernel.org, herbert@gondor.apana.org.au, arnd@arndb.de, gregkh@linuxfoundation.org, sean.wang@kernel.org, linux-mediatek@lists.infradead.org, linux-kernel@vger.kernel.org, wsd_upstream@mediatek.com, robh+dt@kernel.org, linux-crypto@vger.kernel.org, mpm@selenic.com, matthias.bgg@gmail.com, Crystal.Guo@mediatek.com, linux-arm-kernel@lists.infradead.org, mark.rutland@arm.com, Jose.Marinho@arm.com X-SA-Exim-Mail-From: maz@kernel.org X-SA-Exim-Scanned: No (on disco-boy.misterjones.org); SAEximRunCond expanded to false Sender: devicetree-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: devicetree@vger.kernel.org On 2020-06-03 08:54, Neal Liu wrote: > On Wed, 2020-06-03 at 08:40 +0100, Marc Zyngier wrote: >> On 2020-06-03 08:29, Neal Liu wrote: [...] >> > Could you give us a hint how to make this SMC interface more generic in >> > addition to my approach? >> > There is no (easy) way to get platform-independent SMC function ID, >> > which is why we encode it into device tree, and provide a generic >> > driver. In this way, different devices can be mapped and then get >> > different function ID internally. >> >> The idea is simply to have *one* single ID that caters for all >> implementations, just like we did for PSCI at the time. This >> requires ARM to edict a standard, which is what I was referring >> to above. >> >> There is zero benefit in having a platform-dependent ID. It just >> pointlessly increases complexity, and means we cannot use the RNG >> before the firmware tables are available (yes, we need it that >> early). >> >> M. > > Do you know which ARM expert could edict this standard? > Or is there any chance that we can make one? And be reviewed by > maintainers? Sudeep already mentioned Jose's effort to offer a standard. Hopefully he will *soon* be able to give us something that can be implemented everywhere (firmware, kernel, but also hypervisors), as the need exists across the whole stack. M. -- Jazz is not dead. It just smells funny...