From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Date: Mon, 23 Jul 2012 13:49:12 +1000 From: Paul Mackerras To: Benjamin Herrenschmidt Subject: Re: [PATCH -V3 05/11] arch/powerpc: remove masking top 16 bit of va in tlb invalidate Message-ID: <20120723034912.GA5019@drongo> References: <1341839621-28332-1-git-send-email-aneesh.kumar@linux.vnet.ibm.com> <1341839621-28332-6-git-send-email-aneesh.kumar@linux.vnet.ibm.com> <20120722235610.GE17790@bloggs.ozlabs.ibm.com> <1343006528.29855.25.camel@pasglop> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii In-Reply-To: <1343006528.29855.25.camel@pasglop> Cc: linuxppc-dev@lists.ozlabs.org, "Aneesh Kumar K.V" List-Id: Linux on PowerPC Developers Mail List List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , On Mon, Jul 23, 2012 at 11:22:08AM +1000, Benjamin Herrenschmidt wrote: > On Mon, 2012-07-23 at 09:56 +1000, Paul Mackerras wrote: > > > That indicate we should not mask the top 16 bits. So remove the > > same. > > > > Older versions of the architecture (2.02 and earler) require the > > masking, so we can't just unconditionally remove it, since that would > > potentially break POWER5 and PPC970. People are definitely still > > running Linux bare-metal on PPC970s (though arguably not on POWER5). > > Are you sure ? I couldn't convince myself ... the old architectures say > that it only uses some of the bits but it doesn't mark the other ones as > "reserved" (as in must be 0). > > (At least 1.x, I haven't looked at 2.x with x < 03) 2.01 and 2.02 say bits 0..15 must be zero. Paul.