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=-5.8 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI, SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED 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 AE5D1C433DB for ; Fri, 26 Mar 2021 11:57:44 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 7214B61A3F for ; Fri, 26 Mar 2021 11:57:44 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229671AbhCZL5M (ORCPT ); Fri, 26 Mar 2021 07:57:12 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:46860 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229871AbhCZL5F (ORCPT ); Fri, 26 Mar 2021 07:57:05 -0400 Received: from mail-lf1-x12b.google.com (mail-lf1-x12b.google.com [IPv6:2a00:1450:4864:20::12b]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id CA8DFC0613AA for ; Fri, 26 Mar 2021 04:57:04 -0700 (PDT) Received: by mail-lf1-x12b.google.com with SMTP id b4so7257204lfi.6 for ; Fri, 26 Mar 2021 04:57:04 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linaro.org; s=google; h=mime-version:references:in-reply-to:from:date:message-id:subject:to :cc; bh=Y/YJy6ENumZLg5/zvFHAeuvrrpukOzL88n9aSHHrphQ=; b=aPcFuvKdA862pPL2UYtr5TE/4vlFoQDw4Z63nQepN+saeNxNGA8a8zwRoArd6EMTNe aqi4CeEEtvwd9oos84Wc78G8uILwOhZPDHWwew//XfPnQoGfulKcFawY34Dtqw8hiaRs WOVg4XAn2aoc/ti4KVNAdv3fEkVzsPV0IWAja4uJpLWi2v2Xz/DyGIsfU4uTn+vCAEg3 gbh67KaIHrl/NfD418cN+iVzxYLAYpUMRYvyr62fucCYqVUphTW0MAA39icB/uhBrak5 GzdRNbobqXcoX9ag6OvUtO4nNblp+I4IihHqCc/mbM8Wc6L7KL1vPwMfjqF+bd0kgp10 6U2A== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:mime-version:references:in-reply-to:from:date :message-id:subject:to:cc; bh=Y/YJy6ENumZLg5/zvFHAeuvrrpukOzL88n9aSHHrphQ=; b=HuOg05ZAdhj4hwkiG8GcPvtioTBI2YfTGmYd7GtVQiw9G/ALYXmJAPTvlopw0y2jYA 5qA1qqsRlHVT2YlI/UfLtBi6TkcQTvv4Gvte6O9S5Wz6iy4gj22b6hDmFh7L++syJynv n2+hnHttv9yAdDYAPoPNEbfsZe5cvEDMqryaLbXOGO8RsHqbDUlxQcHN0LWa7p5ez3QP G+qDq/AuupVBRUWZaxPQYClZlarNYKH1bo8kBM1RmJAEgGf5LvWhiUAhQ0p765PicGIX mXDvnoWqwYMcFuxhgZ5I254wlmxVedbO0rsab3DgH1mPUO/v4U87IGVYi1K69iXVmVvZ HXYw== X-Gm-Message-State: AOAM532A+0dbpV2qipTnf54hlnQszxshxYF8sbHthYdA3Fm8nPOw7jIk +fK0gGqy3p+PNIDFWAM8PolrJJSmXCXZxzV7M58cmQ== X-Google-Smtp-Source: ABdhPJwK6yp/8uK0rO8yQ6TqoS3aFd/xSINJSltbT5uI17puaOX+o1xEL/vwp04RUP5+w+XCFKiVytIHyeSptHFkUzU= X-Received: by 2002:ac2:5509:: with SMTP id j9mr7768919lfk.302.1616759823215; Fri, 26 Mar 2021 04:57:03 -0700 (PDT) MIME-Version: 1.0 References: <20210325143255.1532452-1-sudeep.holla@arm.com> <20210325143255.1532452-2-sudeep.holla@arm.com> <20210326105545.44rdcbrumg3q6i7y@bogus> In-Reply-To: <20210326105545.44rdcbrumg3q6i7y@bogus> From: Sumit Garg Date: Fri, 26 Mar 2021 17:26:52 +0530 Message-ID: Subject: Re: [PATCH v5 1/7] dt-bindings: Arm: Add Firmware Framework for Armv8-A (FF-A) binding To: Sudeep Holla Cc: linux-arm-kernel , Devicetree List , Trilok Soni , arve@android.com, Andrew Walbran , David Hartley , Achin Gupta , Jens Wiklander , Arunachalam Ganapathy , Marc Bonnici Content-Type: text/plain; charset="UTF-8" Precedence: bulk List-ID: X-Mailing-List: devicetree@vger.kernel.org On Fri, 26 Mar 2021 at 16:25, Sudeep Holla wrote: > > On Fri, Mar 26, 2021 at 10:35:23AM +0530, Sumit Garg wrote: > > Hi Sudeep, > > > > Apologies for catching up late on this patch-set. > > > > On Thu, 25 Mar 2021 at 20:05, Sudeep Holla wrote: > > > > > > Since the FF-A v1.0 specification doesn't list the UUID of all the > > > partitions in the discovery API, we need to specify the UUID of the > > > partitions that need to be accessed by drivers within the kernel. > > > > > > > Wouldn't we be able to implement auto-discovery of ffa partitions? I > > think enumeration of ffa partitions on FFA bus should be quite similar > > to enumeration of TAs on TEE bus (see [1]). Otherwise we need to put > > these redundant DT entries for every ffa partition which IMHO would > > bloat up device trees for every platform. > > > > Any suggestions on how to ? Clearly spec doesn't have that provision, I > had raised this point in the past. Jens has similar concern and he did > ask the same[1]. As I replied to him in that thread[2]. > > I am open to suggestion on how to auto-discover, currently as I see spec > doesn't support it. > Thanks for sharing links to prior discussions and I can see that currently spec doesn't support it. But from an implementation perspective, I can't find any reason that we can't support auto-discover. Have a look at below proposed simple FFA ABI: FFA_LIST_PARTITIONS - No input params. - Returns an array of secure partition UUIDs to which this non-secure virtual/physical FF-A instance is allowed to communicate with. I think with auto-discovery, one of the major benefits is that if the OEM is using a common platform to cater to multiple use-cases which rely on different secure partitions then OEM doesn't have to bother about shipping separate DTs. -Sumit > -- > Regards, > Sudeep > > [1] https://lore.kernel.org/linux-arm-kernel/20201216134659.GA4146223@jade/ > [2] https://lore.kernel.org/linux-arm-kernel/20210113092236.pnabzaufzuzwprmw@bogus/