From mboxrd@z Thu Jan 1 00:00:00 1970 Date: Thu, 9 Jan 2003 13:33:00 +1100 From: David Gibson To: Hollis Blanchard Cc: paulus@samba.org, devel list Subject: Re: get_pteptr prototype Message-ID: <20030109023300.GC6569@zax.zax> References: <1041893967.1207.42.camel@granite.austin.ibm.com> <20030107005751.GP22215@zax.zax> <1042040929.1021.80.camel@granite.austin.ibm.com> <20030108234908.GA1088@zax.zax> <1042071086.1207.206.camel@granite.austin.ibm.com> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii In-Reply-To: <1042071086.1207.206.camel@granite.austin.ibm.com> Sender: owner-linuxppc-dev@lists.linuxppc.org List-Id: On Wed, Jan 08, 2003 at 06:11:25PM -0600, Hollis Blanchard wrote: > > On Wed, 2003-01-08 at 17:49, David Gibson wrote: > > On Wed, Jan 08, 2003 at 09:48:48AM -0600, Hollis Blanchard wrote: > > > It's simply a wrapper around successive pte/pmd/pgd_offset calls, with > > > some error checking. Are you saying those calls are not the correct way > > > to get the PTE pointer for an address? > > > > Trouble is that this will break badly in 2.5 where we use large-page > > entries for the lowmem mapping. > > I'm happy to change it to something 2.5-friendly if someone can suggest > how... > > Alternatively I can add 405LP to the XMON/KGDB/BDI2000 list of ifdefs > that map the whole kernel writable, which would be overkill but avoid > adding PTE manipulations. Hmm... what's the reason that wakeup_info needs to be reserved in head_4xx.S, rather than just being a normal variable in the data area (which should be writable anyway)? Its not obvious to me from the patch. Actually, skimming through the patch I noticed a minor nit: you only have one .long in head_4xx.S reserving space for the wakeup_info struct which is 3 words long. In practice the . = in the exception handlers will give you plenty of space, but I think it would be good form to explicitly reserve the right amount of space. -- David Gibson | For every complex problem there is a david@gibson.dropbear.id.au | solution which is simple, neat and | wrong. http://www.ozlabs.org/people/dgibson ** Sent via the linuxppc-dev mail list. See http://lists.linuxppc.org/