From mboxrd@z Thu Jan 1 00:00:00 1970 Received: with ECARTIS (v1.0.0; list linux-mips); Fri, 07 Oct 2016 17:41:47 +0200 (CEST) Received: from mail-pa0-f68.google.com ([209.85.220.68]:34644 "EHLO mail-pa0-f68.google.com" rhost-flags-OK-OK-OK-OK) by eddie.linux-mips.org with ESMTP id S23992214AbcJGPlkQSlxn (ORCPT ); Fri, 7 Oct 2016 17:41:40 +0200 Received: by mail-pa0-f68.google.com with SMTP id r9so2905449paz.1; Fri, 07 Oct 2016 08:41:40 -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=YdAo5+BCi7QUvPUhP0q5Nuz5AHwgAHAAZaFjS82XDDo=; b=ecNEG7E4ned0PuOi/OWUMQBJvK+OPU38IOkW+0Bl0U8uY85uGtCJvwC5tWD96dll6t Wd/l1MlIzjjDdsTbpSi48hZSPpaoFeSniMdYqYnDpuNdZQLwMOTOVIidcbKrL4xxrx4L /ipGZzgwKlwUN8GLutHzgl5GZ25mty6aWaDKh/8Fe8ZLRCCcs4Hvoe2+xdaPKA7trt/1 bvpMx1B++tjbW5DAe0IG5CitcuhVFDOV7bDucqaCRB/SPBqYQ/6LW2bPpExfvOgtmzjf wdKjPAp57139QYc32ahhdSpPEcFdrBYvkrRpegPc0/GU0XrBWwoNducbPb0a5RmNOVnw wIgQ== 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=YdAo5+BCi7QUvPUhP0q5Nuz5AHwgAHAAZaFjS82XDDo=; b=cUG0ZgZlNvTspkVhfJzFxjYBuE3xTyCVO7YZvkBW9bNJKTd4Gz7yHIYayzLvfmWiBy NJDV6zm2USwEeuPMVQIf/ZGyRB5aewSbwZN7V9fRO8nsK/8rJLRsQXG4iPPNjt4A7vGF WGdTio0hXVwj0yzfrN+W44AtTUte9ebH+/VbUJdREteuM4bsPF1YtOoH9wvzDe+Mjoou wQd2K8LkHrTnys69zDOqHVaclr/XlI/D6cTDMI6eJOBbvD7hx59sJHjFrwyCS1RNluCB 57FJ2IAHN3BAA+bwXqv3zcsawcKOHgLKRulZOD5e3ZayLwl/PeYe6//fKGXLSmyhXp7z c4wg== X-Gm-Message-State: AA6/9RkiGRN4dqEi3CF041sNf+3C4VQV1vq3FqBmuErnv0ldFm0+BuT5OpCOgbyd1I81mA== X-Received: by 10.66.188.202 with SMTP id gc10mr32109949pac.104.1475854894531; Fri, 07 Oct 2016 08:41:34 -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 20sm14956845pfk.13.2016.10.07.08.41.33 (version=TLS1 cipher=AES128-SHA bits=128/128); Fri, 07 Oct 2016 08:41:33 -0700 (PDT) Message-ID: <57F7C229.9040608@gmail.com> Date: Fri, 07 Oct 2016 08:41:29 -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> <57F7C0D5.6000007@gmail.com> In-Reply-To: <57F7C0D5.6000007@gmail.com> 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: 55371 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 10/07/2016 08:35 AM, David Daney wrote: > 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. > One more thing... In r5 systems, the only time 64-bit Ebase is really interesting is for virtualization. You could also gate probing WG on the presence of the VZ capability. > David. > > >