From mboxrd@z Thu Jan 1 00:00:00 1970 Message-ID: <3A63BAFB.80E3980C@mvista.com> Date: Mon, 15 Jan 2001 19:07:39 -0800 From: Frank Rowand Reply-To: frowand@mvista.com MIME-Version: 1.0 To: Dan Malek CC: linuxppc-dev Subject: Re: kernel mapping References: <3A63840E.4C724E03@mvista.com> Content-Type: text/plain; charset=us-ascii Sender: owner-linuxppc-dev@lists.linuxppc.org List-Id: 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 ** Sent via the linuxppc-dev mail list. See http://lists.linuxppc.org/