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=-1.0 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,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 D3DE9C33CA1 for ; Mon, 20 Jan 2020 09:42:15 +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 A11C0207E0 for ; Mon, 20 Jan 2020 09:42:15 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=lists.infradead.org header.i=@lists.infradead.org header.b="lWrZhFnS"; dkim=fail reason="signature verification failed" (1024-bit key) header.d=kernel.org header.i=@kernel.org header.b="zrwVMlIQ" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org A11C0207E0 Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=kernel.org 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-Type: Content-Transfer-Encoding:Cc:List-Subscribe:List-Help:List-Post:List-Archive: List-Unsubscribe:List-Id:Message-ID:References:In-Reply-To:Subject:To:From: Date:MIME-Version:Reply-To:Content-ID:Content-Description:Resent-Date: Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:List-Owner; bh=CmXbE6wvD93jaFxyhwNH6RbWttGuAeVHw78nmfg1pmM=; b=lWrZhFnSxXrBDHGsGmWpPf4j2 v/ZBBHeDUlEd513DD9g8M6s6ZyCwRD+Ng+BWpx5zefd9kjra9rsD/XEqj7clcrAvJ/6mXR6p5v84T i/YTU4J6SY2ze+bonil0owDtK/STD4LAFbnHpeKNNHgDo67ZCT/PIIkJ/m8ufi/KPTVXyxeCK/FUE /LKmgfKMntFzipAFzRDxWOCsmgjcovtBRF3OGmmGfbSHrbLM7j2raZWuyQuJ9PpW57UKpIsGC+sBj R9SxLCH3uQ87ggrbEdUzCJh36OQew2spLxhhnokP8IU/sbkCsD1MoRJ45XFojDBiZtBmo79nlvuxr 5xelUIzDg==; 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 1itTZR-0006Ol-2y; Mon, 20 Jan 2020 09:42:09 +0000 Received: from mail.kernel.org ([198.145.29.99]) by bombadil.infradead.org with esmtps (Exim 4.92.3 #3 (Red Hat Linux)) id 1itTZK-0006OK-TP for linux-arm-kernel@lists.infradead.org; Mon, 20 Jan 2020 09:42:06 +0000 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 1CA8F207E0; Mon, 20 Jan 2020 09:42:01 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1579513321; bh=NL+jWrz2kmdaOfiDcTAo2c2l6MRY04yThDjnVS/6tSI=; h=Date:From:To:Cc:Subject:In-Reply-To:References:From; b=zrwVMlIQSMOiJ+5pq3cBQpJwEKc6MfoE49dC0kiB+fsjDwwMlf0jzXBc9LK7wc8y/ rp4qID1pHewANcrIwBtaGJRNnQ2ODBpdkaUy6vhm4B4DVuZVOdWARepUOJqvIMHWBJ kK1F7L0IvJLxRAPwZvQ056N0Q7YEz5R83z92LoA4= 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 1itTZH-000EA4-Ew; Mon, 20 Jan 2020 09:41:59 +0000 MIME-Version: 1.0 Date: Mon, 20 Jan 2020 10:41:59 +0100 From: Marc Zyngier To: Steven Miao , Tao Zeng Subject: Re: Questions about /proc/cpuinfo for arch-ARM - CAS-149046-Y1H3T8 In-Reply-To: References: Message-ID: <22d48abd5ab2813b18e952b5d911152c@misterjones.org> X-Sender: maz@kernel.org User-Agent: Roundcube Webmail/1.3.8 X-SA-Exim-Connect-IP: 51.254.78.96 X-SA-Exim-Rcpt-To: Steven.Miao@arm.com, prime.zeng@hisilicon.com, support-software@arm.com, Mark.Rutland@arm.com, Robin.Murphy@arm.com, linux-arm-kernel@lists.infradead.org X-SA-Exim-Mail-From: maz@kernel.org X-SA-Exim-Scanned: No (on disco-boy.misterjones.org); SAEximRunCond expanded to false X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20200120_014202_991264_C9C98527 X-CRM114-Status: GOOD ( 15.14 ) 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 , Robin Murphy , linux-arm-kernel@lists.infradead.org, Support-Software Content-Transfer-Encoding: 7bit Content-Type: text/plain; charset="us-ascii"; Format="flowed" Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+infradead-linux-arm-kernel=archiver.kernel.org@lists.infradead.org Hi Steven, On 2020-01-20 10:24, Steven Miao wrote: > CC arm mailing list. Someone know the whole history may have a better > answer. > > Thanks, > Steven > > From: Support-Software > Sent: Monday, January 20, 2020 5:17 PM > To: Tao Zeng > Cc: Mark Rutland > Subject: Re: Questions about /proc/cpuinfo for arch-ARM - > CAS-149046-Y1H3T8 > > From Steven Miao - Arm Partner Enablement Group > Please quote case reference number > https://support.developer.arm.com/case-details/?id=f9beb263-333b-ea11-a813-000d3ab4f2f3 > in any further emails to us on this subject. > > Hi Tao, >> 1. Since /proc/cpuinfo is treated as ABI, so where can I find the >> specification? Or is there any docs >> to describe the details? Or it is just some applications who have >> already token it? > I think it is just de-facto ABI legacy application are relying on, > there's no such specification. >> You know that, in x86, /proc/cpuinfo provide really good user >> experience, >> what we want to do is providing the same or even better user >> experience. Tao: And by "better user experience", you mean breaking existing software? I'm sure users will enjoy the "improvement". > We should add new stuff to /sys/, don't add new things to /proc. On > x86 these strings are acquired from the CPU itself, via CPUID > instructions, which means that it works for future CPUs. For ARM > systems, we have no consistent way of acquiring a model name from a > CPU itself. If users who want to decode MIDRs are going to have to use > userspace tools. > Changing current cpuinfo: > - it breaks existing applications > - it is unmaintainable in the long run > - we can already get cpu information by dmidecode, lscpu, lshw... Exactly. The subject has been rehashed to death, and is not up for discussion anymore. /proc/cpuinfo is ABI, which means its format is forever immutable. Userspace has all the required tools at its disposal. M. -- Jazz is not dead. It just smells funny... _______________________________________________ linux-arm-kernel mailing list linux-arm-kernel@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-arm-kernel