From mboxrd@z Thu Jan 1 00:00:00 1970 Received: with ECARTIS (v1.0.0; list linux-mips); Thu, 09 Jan 2003 01:36:11 +0000 (GMT) Received: from p508B6BF1.dip.t-dialin.net ([IPv6:::ffff:80.139.107.241]:15840 "EHLO dea.linux-mips.net") by linux-mips.org with ESMTP id ; Thu, 9 Jan 2003 01:36:10 +0000 Received: (from ralf@localhost) by dea.linux-mips.net (8.11.6/8.11.6) id h091a1a03540; Thu, 9 Jan 2003 02:36:01 +0100 Date: Thu, 9 Jan 2003 02:36:01 +0100 From: Ralf Baechle To: "Maciej W. Rozycki" Cc: Mike Uhler , Dominic Sweetman , linux-mips@linux-mips.org Subject: Re: [patch] Use XKPHYS for 64-bit TLB flushes Message-ID: <20030109023601.A1213@linux-mips.org> References: <20030108204408.A27888@linux-mips.org> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline User-Agent: Mutt/1.2.5.1i In-Reply-To: ; from macro@ds2.pg.gda.pl on Wed, Jan 08, 2003 at 09:12:03PM +0100 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: 1104 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 Wed, Jan 08, 2003 at 09:12:03PM +0100, Maciej W. Rozycki wrote: > Well, like it or not, CAMs do not like multiple matches -- up to a > physical damage even. So they should be avoided if possible. While KSEG0 > won't match for any real address translation, there is a non-zero > probability of executing a tlbp for it as a result of buggy code or > execution gone wild (root running crashme?). I'm told the TLB Shutdown bit in the R4000 is basically implemented as an overcurrent protection. That is on many chips even a hit on several entries won't cause a tlb shutdown until the matches do result in the TLB drawing more than a certain current. A tlbp on a KSEG0 address shouldn't happen. If it's attempted we already have worse problems. Ralf