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=-2.4 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,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 CCE08C433E1 for ; Thu, 21 May 2020 19:52:22 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id AE93020738 for ; Thu, 21 May 2020 19:52:22 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=ti.com header.i=@ti.com header.b="I/yi5K88" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1729397AbgEUTwW (ORCPT ); Thu, 21 May 2020 15:52:22 -0400 Received: from fllv0016.ext.ti.com ([198.47.19.142]:42470 "EHLO fllv0016.ext.ti.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1729091AbgEUTwW (ORCPT ); Thu, 21 May 2020 15:52:22 -0400 Received: from lelv0266.itg.ti.com ([10.180.67.225]) by fllv0016.ext.ti.com (8.15.2/8.15.2) with ESMTP id 04LJq3rW081620; Thu, 21 May 2020 14:52:03 -0500 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=ti.com; s=ti-com-17Q1; t=1590090723; bh=Vb/5S9ewFa3yrp3KZRQqIR2YgutT5LYsiuL4DYpKPE8=; h=Subject:To:CC:References:From:Date:In-Reply-To; b=I/yi5K88+YAIrR3aTAnM80hh9e++JV72R6OISQRJNEQCWBfbw7PKgAtAHkIXQvRCp qZZB7bqz9rN1+fjlAUn+EhskN+VDNzUJLTOFFIN52UU9RykxYqzdtofgrtslyqafPE gfx874K5k8FDDS6F0Fa8SMP5KCsG9Me/zQrx+lcQ= Received: from DLEE106.ent.ti.com (dlee106.ent.ti.com [157.170.170.36]) by lelv0266.itg.ti.com (8.15.2/8.15.2) with ESMTPS id 04LJq35u024370 (version=TLSv1.2 cipher=AES256-GCM-SHA384 bits=256 verify=FAIL); Thu, 21 May 2020 14:52:03 -0500 Received: from DLEE100.ent.ti.com (157.170.170.30) by DLEE106.ent.ti.com (157.170.170.36) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_CBC_SHA256_P256) id 15.1.1979.3; Thu, 21 May 2020 14:52:03 -0500 Received: from fllv0039.itg.ti.com (10.64.41.19) by DLEE100.ent.ti.com (157.170.170.30) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_CBC_SHA256_P256) id 15.1.1979.3 via Frontend Transport; Thu, 21 May 2020 14:52:03 -0500 Received: from [10.250.48.148] (ileax41-snat.itg.ti.com [10.172.224.153]) by fllv0039.itg.ti.com (8.15.2/8.15.2) with ESMTP id 04LJq3Sc036393; Thu, 21 May 2020 14:52:03 -0500 Subject: Re: [PATCH 2/4] remoteproc: introduce version element into resource type field To: Bjorn Andersson CC: Rob Herring , Mathieu Poirier , Clement Leger , Loic Pallardy , Arnaud Pouliquen , Lokesh Vutla , , , , References: <20200325204701.16862-1-s-anna@ti.com> <20200325204701.16862-3-s-anna@ti.com> <20200521175421.GI408178@builder.lan> <20200521192146.GO408178@builder.lan> <57ae5678-fd0a-07a8-6165-a2cf7ccdef88@ti.com> <20200521194116.GP408178@builder.lan> From: Suman Anna Message-ID: <5529e8ff-b5ed-9dd6-e7f6-55a00225c2b9@ti.com> Date: Thu, 21 May 2020 14:52:02 -0500 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:68.0) Gecko/20100101 Thunderbird/68.7.0 MIME-Version: 1.0 In-Reply-To: <20200521194116.GP408178@builder.lan> Content-Type: text/plain; charset="utf-8"; format=flowed Content-Language: en-US Content-Transfer-Encoding: 7bit X-EXCLAIMER-MD-CONFIG: e1e8a2fd-e40a-4ac6-ac9b-f7e9cc9ee180 Sender: linux-remoteproc-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-remoteproc@vger.kernel.org On 5/21/20 2:41 PM, Bjorn Andersson wrote: > On Thu 21 May 12:29 PDT 2020, Suman Anna wrote: > >> On 5/21/20 2:21 PM, Bjorn Andersson wrote: >>> On Thu 21 May 12:06 PDT 2020, Suman Anna wrote: >>> >>>> Hi Bjorn, >>>> >>>> On 5/21/20 12:54 PM, Bjorn Andersson wrote: >>>>> On Wed 25 Mar 13:46 PDT 2020, Suman Anna wrote: >>>>> >>>>>> The current remoteproc core has supported only 32-bit remote >>>>>> processors and as such some of the current resource structures >>>>>> may not scale well for 64-bit remote processors, and would >>>>>> require new versions of resource types. Each resource is currently >>>>>> identified by a 32-bit type field. Introduce the concept of version >>>>>> for these resource types by overloading this 32-bit type field >>>>>> into two 16-bit version and type fields with the existing resources >>>>>> behaving as version 0 thereby providing backward compatibility. >>>>>> >>>>>> The version field is passed as an additional argument to each of >>>>>> the handler functions, and all the existing handlers are updated >>>>>> accordingly. Each specific handler will be updated on a need basis >>>>>> when a new version of the resource type is added. >>>>>> >>>>> >>>>> I really would prefer that we add additional types for the new >>>>> structures, neither side will be compatible with new versions without >>>>> enhancements to their respective implementations anyways. >>>> >>>> OK. >>>> >>>>> >>>>>> An alternate way would be to introduce the new types as completely >>>>>> new resource types which would require additional customization of >>>>>> the resource handlers based on the 32-bit or 64-bit mode of a remote >>>>>> processor, and introduction of an additional mode flag to the rproc >>>>>> structure. >>>>>> >>>>> >>>>> What would this "mode" indicate? If it's version 0 or 1? >>>> >>>> No, for indicating if the remoteproc is 32-bit or 64-bit and adjust the >>>> loading handlers if the resource types need to be segregated accordingly. >>>> >>> >>> Sorry, I think I'm misunderstanding something. Wouldn't your 64-bit >>> remote processor need different firmware from your 32-bit processor >>> anyways, if you want to support the wider resource? And you would pack >>> your firmware with the appropriate resource types? >> >> Yes, that's correct. >> >>> >>> Afaict the bit width of your remote processor, busses or memory is >>> unrelated to the choice of number of bits used to express things in the >>> resource table. >> >> I would have to add the new resource type to the loading_handlers right, so >> it is a question of whether we want to impose any restrictions in remoteproc >> core or not from supporting a certain resource type (eg: I don't expect >> RSC_TRACE entries on 64-bit processors). >> > > Right, but either you add support for new resource types to the > loading_handlers, or you add the version checks within each handler, > either way you will have to do some work to be compatible with new > versions. > > Regarding what resources would be fit for a 64-bit processor probably > relates to many things, in particular the question of what we actually > mean when we say that a coprocessor is 64-bit. So I don't really see a > need for the remoteproc core to prevent someone to design their > system/firmware to have a 64-bit CPU being passed 32-bit addresses. OK. In general, I have seen firmware developers get confused w.r.t the resource types, that's why I was inclined to go with the restrictive checking. Anyway, will rework the support as per the comments. regards Suman