From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (qmail 117301 invoked by alias); 26 Jun 2015 12:06:11 -0000 Mailing-List: contact gcc-patches-help@gcc.gnu.org; run by ezmlm Precedence: bulk List-Id: List-Archive: List-Post: List-Help: Sender: gcc-patches-owner@gcc.gnu.org Received: (qmail 117285 invoked by uid 89); 26 Jun 2015 12:06:11 -0000 Authentication-Results: sourceware.org; auth=none X-Virus-Found: No X-Spam-SWARE-Status: No, score=3.1 required=5.0 tests=AWL,BAYES_50,KAM_LAZY_DOMAIN_SECURITY,RCVD_IN_DNSWL_NONE,RCVD_IN_JMF_BL autolearn=no version=3.3.2 X-HELO: bin-vsp-out-05.atm.binero.net Received: from vsp-unauthed02.binero.net (HELO bin-vsp-out-05.atm.binero.net) (195.74.38.227) by sourceware.org (qpsmtpd/0.93/v0.84-503-g423c35a) with (AES256-GCM-SHA384 encrypted) ESMTPS; Fri, 26 Jun 2015 12:06:09 +0000 X-Halon-ID: b8d0e7c4-1bfb-11e5-8d36-005056916f53 Authorized-sender: support@gaisler.com Received: from [192.168.0.86] (unknown [81.170.187.120]) by bin-vsp-out-05.atm.binero.net (Halon Mail Gateway) with ESMTPSA; Fri, 26 Jun 2015 14:06:05 +0200 (CEST) Message-ID: <558D4033.7000405@gaisler.com> Date: Fri, 26 Jun 2015 12:06:00 -0000 From: Daniel Cederman User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:31.0) Gecko/20100101 Thunderbird/31.7.0 MIME-Version: 1.0 To: Eric Botcazou CC: gcc-patches@gcc.gnu.org, daniel@gaisler.com, jakub@redhat.com, sebastian.huber@embedded-brains.de Subject: Re: [PATCH] Make muser-mode the default for LEON3 References: <1435068612-1477-1-git-send-email-cederman@gaisler.com> <4129005.H3mTZTLn52@polaris> In-Reply-To: <4129005.H3mTZTLn52@polaris> Content-Type: text/plain; charset=windows-1252; format=flowed Content-Transfer-Encoding: 7bit X-IsSubscribed: yes X-SW-Source: 2015-06/txt/msg01939.txt.bz2 > > Do they lack the CASA instruction with supervisor-mode ASI? What happens when > the CASA instruction with user-mode ASI is executed in supervisor mode? > For all LEON3 (with CASA support) the CASA instruction works in supervisor-mode regardless of ASI used. In user-mode CASA only works with the user-mode ASI. So CASA with user-mode ASI works for both user-mode and supervisor-mode. By having user-mode ASI as default, one would not need to change flag when compiling user or kernel code. On a few old LEON3 systems the CASA instruction only works in supervisor mode. Using the CASA instruction with the user-mode ASI on these systems is not legal and will cause a trap. -- Daniel Cederman