From mboxrd@z Thu Jan 1 00:00:00 1970 Message-ID: <3A643283.A20200E8@raleigh.ibm.com> Date: Tue, 16 Jan 2001 06:37:39 -0500 From: Ralph Blach MIME-Version: 1.0 To: frowand@mvista.com CC: linuxppc-dev Subject: Re: kernel mapping References: <3A63840E.4C724E03@mvista.com> <3A63BAFB.80E3980C@mvista.com> Content-Type: multipart/mixed; boundary="------------239A656DB394CD1678244028" Sender: owner-linuxppc-dev@lists.linuxppc.org List-Id: This is a multi-part message in MIME format. --------------239A656DB394CD1678244028 Content-Type: text/plain; charset=us-ascii Content-Transfer-Encoding: 7bit Why do we need simulated bat registers. Chip Frank Rowand wrote: > > Dan Malek wrote: > > > > How come we don't use iopa() and friends for all kernel mapping > > information? It is only defined for CONFIG_APUS, but is the right > > thing to use on 8xx and 4xx, and probably all processors. The > > virt_to_bus/bus_to_virt contain the quickie arithmetic hack with > > KERNELBASE, but that isn't the right thing to do for any kmalloc() > > or valloc() space or if you don't have BAT mapping. > > > > I am considering making these functions more generic, removing the > > #ifdefs, and implementing "simulated" BAT mapping for processors > > like the 8xx and 4xx that don't have BATs (not for 2.4, of course :-). > > > > Why shouldn't I do this? > > > > -- Dan > > For the 405 I had to use iopa() for virt_to_bus() because there are > cases where I create a virtual address for IO buffers that is > uncached, and that virtual address is not (physical address + KERNELBASE). > I also have the beginnings of simulated BAT mapping for the 405 > (not quite there, but part way). > > -Frank > -- > Frank Rowand > MontaVista Software, Inc > --------------239A656DB394CD1678244028 Content-Type: text/x-vcard; charset=us-ascii; name="rcblach.vcf" Content-Description: Card for Ralph Blach Content-Disposition: attachment; filename="rcblach.vcf" Content-Transfer-Encoding: 7bit begin:vcard n:Blach;Ralph tel;work:919-543-1207 x-mozilla-html:TRUE url:www.ibm.com org:IBM MicroElectronics adr:;;3039 Cornwallis ;RTP;NC;27709;USA version:2.1 email;internet:rcblach@raleigh.ibm.com x-mozilla-cpt:;15936 fn:Ralph Blach end:vcard --------------239A656DB394CD1678244028-- ** Sent via the linuxppc-dev mail list. See http://lists.linuxppc.org/