From mboxrd@z Thu Jan 1 00:00:00 1970 Message-ID: <3ABA441C.6261BC52@mvista.com> Date: Thu, 22 Mar 2001 13:27:40 -0500 From: Dan Malek MIME-Version: 1.0 To: Ralph Blach Cc: linuxppc-embedded@lists.linuxppc.org, David Blythe Subject: Re: Proposed new kernel noncaching memory allocator for the 405gp References: <3ABA1B6A.87C5FE9B@intrex.net> <3ABA291D.A7A82D8A@mvista.com> <3ABA3A5B.2EFA8D6D@intrex.net> Content-Type: text/plain; charset=us-ascii Sender: owner-linuxppc-embedded@lists.linuxppc.org List-Id: Ralph Blach wrote: > Using these in the OHCI driver would greatly simply the driver because the > TD would not be cached. I'm not sure that is for us to decide. I don't really want to know that much detail about USB, and the experts that ported these drivers to processors without cache coherent DMA requested the functions as you see them now. If they decide they want something different, we'll provide those. The IBM4xx is a late-comer to the issues of ensuring cache coherency, and all we are doing is adopting existing functions that standard Linux software has been using on other platforms. > Where are these functions that you say you have implemented? arch/ppc/8xx_io/commproc.c allocates one (or more) pages of memory during early initialization, marks them uncached, and will allocate a few bytes for some drivers. I think only the uart driver uses this right now for allocating its DMA FIFOs. -- Dan ** Sent via the linuxppc-embedded mail list. See http://lists.linuxppc.org/