From mboxrd@z Thu Jan 1 00:00:00 1970 Received: with ECARTIS (v1.0.0; list linux-mips); Fri, 07 Oct 2016 17:36:05 +0200 (CEST) Received: from mail-pa0-f53.google.com ([209.85.220.53]:34767 "EHLO mail-pa0-f53.google.com" rhost-flags-OK-OK-OK-OK) by eddie.linux-mips.org with ESMTP id S23992214AbcJGPf6n0Vwn (ORCPT ); Fri, 7 Oct 2016 17:35:58 +0200 Received: by mail-pa0-f53.google.com with SMTP id rz1so24204473pab.1; Fri, 07 Oct 2016 08:35:58 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20120113; h=message-id:date:from:user-agent:mime-version:to:cc:subject :references:in-reply-to:content-transfer-encoding; bh=+HjtGJPeFFaUqPNU99ZHVv+WhU7A8y0gCD6tYNiYYcw=; b=YzmWpjIl4q0qwjvE9pXXJmsUEzrwxm1eAYPD9i+Jy5hIscXBJhuBNNcBko3P1kdUiL MA+oG/Chpbg0ikHhgRZZxRBSYyk4lvSVWQ8vtRsvgtmwYRrEd7oHi2LdTbAbV1Kg865q B9HgR2mSoav6Q+JDaBsvohA1y0mYyeka4oZZUZuLnPH/deeyaJtqCoZsY8OiU3cEDLC3 age3cEYyJTtGNFrOZVy5IOXQAnrsuF3DvIgxxmU+/xNLxxeUo5nTxIqc74zzGlmLrsyY 9qWjM+1OgyLvrCjujkRBGAZQrQBY3PqUjaNrYNlqoEDFwZI7gg06Xyi1or+DrvztHuhg 4WGw== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20130820; h=x-gm-message-state:message-id:date:from:user-agent:mime-version:to :cc:subject:references:in-reply-to:content-transfer-encoding; bh=+HjtGJPeFFaUqPNU99ZHVv+WhU7A8y0gCD6tYNiYYcw=; b=IfzJNJ588El8sYKqFDz54VNJAmZFrLhi9UB9kqTYgaOupA2QX8CZa4kiWTtzDf/7JG Nt7JjaIhsv7Xwkia5kg/Fy+7m1Hd8DaQyVkLd351EVxRgbLUvDsrScyU+w30PJFsVO+u yWlyGueq4ysHsOzppnxOENywc+P8U2s7ZpVxg7/EpI6S0MKMKVk1qadwCw3CZ2zs4Kf5 go9D8DOBpLJJBvC56pMj8X1TrCJaP9BWdytZnFoKtaXoemmTxR8HdHuXWvZA/PbSdvEt 6QG2JDZ5FNI0P9kyfHgFEZvG8Al11+SmCBLS178OzI/m8HA0y8msI8Wb0yPhgiL4G6jM IXtg== X-Gm-Message-State: AA6/9RlyoHkw4Z3q/NZDzhO3FhoyiuFpmjWGYKiBM3q0QFvvR5/eO3PfTjTsX31Z1XWZeg== X-Received: by 10.66.144.41 with SMTP id sj9mr30968664pab.97.1475854552371; Fri, 07 Oct 2016 08:35:52 -0700 (PDT) Received: from dl.caveonetworks.com (50-233-148-156-static.hfc.comcastbusiness.net. [50.233.148.156]) by smtp.googlemail.com with ESMTPSA id bx5sm5760220pad.6.2016.10.07.08.35.50 (version=TLS1 cipher=AES128-SHA bits=128/128); Fri, 07 Oct 2016 08:35:50 -0700 (PDT) Message-ID: <57F7C0D5.6000007@gmail.com> Date: Fri, 07 Oct 2016 08:35:49 -0700 From: David Daney User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:17.0) Gecko/20130625 Thunderbird/17.0.7 MIME-Version: 1.0 To: "Maciej W. Rozycki" CC: James Hogan , Matt Redfearn , Ralf Baechle , linux-mips@linux-mips.org Subject: Re: [PATCH 1/9] MIPS: traps: 64bit kernels should read CP0_EBase 64bit References: <20160921130852.GA10899@linux-mips.org> <73eede89-af68-eb17-b0b3-2537084da819@imgtec.com> <20161005155653.GG15578@jhogan-linux.le.imgtec.org> In-Reply-To: Content-Type: text/plain; charset=ISO-8859-1; format=flowed 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: 55370 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: ddaney.cavm@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 10/06/2016 09:18 AM, Maciej W. Rozycki wrote: > Hi James, > >>> This does look wrong to me, as I noted above EBase is 64-bit with MIPS64 >>> processors as from architecture revision 3.50. Also I don't think we want >> >> MIPS64 PRA (I'm looking at r5 and r6) seems to allow for write-gate not >> to be implemented, in which case the register is only 32-bits. > > Indeed, but we need to be prepared to handle the width of 64 bits and > `cpu_has_mips64r6' does not seem to me to be the right condition. It is not the proper condition. The presence of a 64-bit EBase should be probed for. The proper check is to test of the EBase[WG] (bit 11) can be set to 1. It it can, this indicates that EBase supports 64-bit accesses. David.