From mboxrd@z Thu Jan 1 00:00:00 1970 Received: with ECARTIS (v1.0.0; list linux-mips); Mon, 03 Oct 2005 14:24:57 +0100 (BST) Received: from extgw-uk.mips.com ([62.254.210.129]:20997 "EHLO bacchus.net.dhis.org") by ftp.linux-mips.org with ESMTP id S3465651AbVJCNYl (ORCPT ); Mon, 3 Oct 2005 14:24:41 +0100 Received: from dea.linux-mips.net (localhost.localdomain [127.0.0.1]) by bacchus.net.dhis.org (8.13.4/8.13.1) with ESMTP id j93DOAcg019890; Mon, 3 Oct 2005 14:24:10 +0100 Received: (from ralf@localhost) by dea.linux-mips.net (8.13.4/8.13.4/Submit) id j93DO889019889; Mon, 3 Oct 2005 14:24:08 +0100 Date: Mon, 3 Oct 2005 14:24:08 +0100 From: Ralf Baechle To: Daniel Jacobowitz Cc: "Maciej W. Rozycki" , Andrew Isaacson , linux-mips@linux-mips.org Subject: Re: [patch 1/5] SiByte fixes for 2.6.12 Message-ID: <20051003132408.GG2624@linux-mips.org> References: <20050622230042.GA17919@broadcom.com> <20051001092807.GD14463@linux-mips.org> <20051003131551.GA19075@nevyn.them.org> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20051003131551.GA19075@nevyn.them.org> User-Agent: Mutt/1.4.2.1i 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: 9122 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: ralf@linux-mips.org Precedence: bulk X-list: linux-mips On Mon, Oct 03, 2005 at 09:15:52AM -0400, Daniel Jacobowitz wrote: > > > Well, the flag is not really to specify whether the common code is to be > > > used or not. It's about whether the TLB is like that of the R4k. > > > Actually it's always been a mystery for me why the common code cannot be > > > used for the SB1, but perhaps there is something specific that I could > > > only discover in that "SB-1 Core User Manual" that I yet have to see, > > > sigh... > > > > > > Of course if your TLB is indeed different from that of the R4k, then you > > > shouldn't be setting cp0.config.mt to 1 in the first place... > > > > The reason was primarily the tiny bit of extra performance because the > > SB1 doesn't need the hazard handling overhead. Also tlb-sb1 has a few > > changes that are needed to initialize a TLB in undefined state after > > powerup. That was needed to run Linux on firmware-less SB1 cores. > > FYI, all I have is a piece of hard evidence: this patch was the > difference between not booting and booting for a Sentosa with CFE. > Which isn't firmwareless and isn't a tiny bit of extra performance > issue. > > I'll try to give CVS HEAD a shot this week sometime. Just as reminder for everybody - CVS is dead and frozen, the action is playing on git now ... Ralf