From mboxrd@z Thu Jan 1 00:00:00 1970 Received: with ECARTIS (v1.0.0; list linux-mips); Thu, 11 Feb 2016 02:59:37 +0100 (CET) Received: from mail-pf0-f194.google.com ([209.85.192.194]:34893 "EHLO mail-pf0-f194.google.com" rhost-flags-OK-OK-OK-OK) by eddie.linux-mips.org with ESMTP id S27010896AbcBKB7fZh6lb (ORCPT ); Thu, 11 Feb 2016 02:59:35 +0100 Received: by mail-pf0-f194.google.com with SMTP id w128so1211743pfb.2; Wed, 10 Feb 2016 17:59:35 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20120113; h=subject:to:references:cc:from:message-id:date:user-agent :mime-version:in-reply-to:content-type:content-transfer-encoding; bh=ryEF5ONVQ2P2w2oGNAPtUDzY/I1hIF/L+wr8Epdnxl8=; b=tv45LA2UPWxp1JBt8FKntF6767IJDGd9OKvkyPTWzlCHz5nbm1gVoMqo+PTrCop+lB ULlfF2yXC80Zf38IdRAu83n1jZcB0svkGn/cdE4GpF18wSongJe+EyBKMrQc5XPTYThf XT9Qnb8mz63qsnWVCv9rf2U3flNyz/qmD8JHtt7OeU4MNFlTKUzu3AhoEuMxXggT0ZdS C6NU+1EFj9b5sTrQGFY53wMTR2mM21/A2uQW0Az1XnM//aZuLjaWHk1JRlbdl0AKYtwk j8mGq4aj3AVMz3kR4Z/w2PdHhd5E55Dm9qWNZxTFI1lBeubCdKgR1TV+9RTTaFq85P6V WdVA== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20130820; h=x-gm-message-state:subject:to:references:cc:from:message-id:date :user-agent:mime-version:in-reply-to:content-type :content-transfer-encoding; bh=ryEF5ONVQ2P2w2oGNAPtUDzY/I1hIF/L+wr8Epdnxl8=; b=l5k/qaLpAg47udM51v3oMBY1mg+EVG26xIJgta5VwnzZSne8Z/moCLNtwTZB7vKOZ3 JDXf2z1sXmjHDUsDHwBXptY7ZPC75H0p2r3cDc7fweB46dOpQ4TjSgd8r8r29ZziRZL/ 072vhwdGmjXAqqiKPHFGKslQ/iBzCfil7RU1CIvfr5wWO3zLD63F20waTGWU35dUoU3N OZBM46EGaR/2I45qRGKlXLb2/Pm9BPLNIAQ3LEhketb/DL2Wpf35OJ49W2vM4M0pB/XW fnC2v9W6jRCVFIc0iS9MuIzDTH+MnVxs2fNsJg5pBYJEQ4cBO8cpHmI/pSrTDtBR3sVA S9bA== X-Gm-Message-State: AG10YOQAcDwaFHZLCgQnnLup/GNgLygtggzbHQF2trzQakQW1TzYys5IvF/dAMRGQMapZw== X-Received: by 10.98.14.149 with SMTP id 21mr62948179pfo.79.1455155969171; Wed, 10 Feb 2016 17:59:29 -0800 (PST) Received: from [10.12.156.244] (5520-maca-inet1-outside.broadcom.com. [216.31.211.11]) by smtp.googlemail.com with ESMTPSA id u64sm7928611pfa.86.2016.02.10.17.59.27 (version=TLS1_2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Wed, 10 Feb 2016 17:59:28 -0800 (PST) Subject: Re: [PATCH 6/6] MIPS: Expose current_cpu_data.options through debugfs To: Ralf Baechle References: <1455051354-6225-1-git-send-email-f.fainelli@gmail.com> <1455051354-6225-7-git-send-email-f.fainelli@gmail.com> <20160210104629.GA11091@linux-mips.org> Cc: linux-mips@linux-mips.org, blogic@openwrt.org, cernekee@gmail.com, jon.fraser@broadcom.com, pgynther@google.com, paul.burton@imgtec.com, ddaney.cavm@gmail.com From: Florian Fainelli Message-ID: <56BBEABF.8030804@gmail.com> Date: Wed, 10 Feb 2016 17:58:23 -0800 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:38.0) Gecko/20100101 Thunderbird/38.5.1 MIME-Version: 1.0 In-Reply-To: <20160210104629.GA11091@linux-mips.org> Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: 7bit Return-Path: X-Envelope-To: <"|/home/ecartis/ecartis -s linux-mips"> (uid 0) X-Orcpt: rfc822;linux-mips@linux-mips.org Original-Recipient: rfc822;linux-mips@linux-mips.org X-archive-position: 51986 X-ecartis-version: Ecartis v1.0.0 Sender: linux-mips-bounce@linux-mips.org Errors-to: linux-mips-bounce@linux-mips.org X-original-sender: f.fainelli@gmail.com Precedence: bulk List-help: List-unsubscribe: List-software: Ecartis version 1.0.0 List-Id: linux-mips X-List-ID: linux-mips List-subscribe: List-owner: List-post: List-archive: X-list: linux-mips On 10/02/16 02:46, Ralf Baechle wrote: > On Tue, Feb 09, 2016 at 12:55:54PM -0800, Florian Fainelli wrote: > >> Debugging a missing features in cpu-features-override.h, or a runtime feature >> set/clear in the vendor specific cpu_probe() function can be a little tedious, >> ease that by providing a debugfs entry representing the >> current_cpu_data.options bitmask. > > Hm.. Bits in the options bitmaps are not an ABI, they come and sometimes > they go as well and manual decoding can be tedious to humans. so I'm > wondering if something in /sys/devices/system/cpu would be more suitable. Not sure, you need this while bringing up systems and/or debugging why a kernel does not have this or that enabled as you think it should, outside of that, not so much probably?. More standard interfaces like /proc/cpuinfo should be used, but that does not give you the full picture. > It'd depend on just sysfs, not debugfs which is disabled in production > kernels. > > Thoughts? I suppose this is fine, in that case, we would probably want to go with a text-based approach to make the interface more stable. NB: I also have a patch that adds cache info reporting to MIPS, since it seems useful for people dealing with user-space cache flushes (graphics, JIT, etc.), Russell King rejected adding that for ARM, but ARM64 and x86 have it (arch/arm64/kernel/cacheinfo.c) would you oppose to having that for MIPS? -- Florian