Subject: Re: New API for non cache coherent ppc cpu's

From: Dan Malek <[email-masked]>
Date: Fri, 23 Nov 2001 11:08:29 -0500

Paul Mackerras wrote:

> To go with pci_map_page and pci_unmap_page.  These give you the
> ability to do DMA to highmem pages without using bounce buffers.

IIRC, there was a virt_to_bus in the code at one time, making it
unusable for highmem pages, which is why I couldn't understand
the appearance of the function.

> My preference would be to make the one set of functions work
> everywhere.

Mine, too.  I just wish this was a common concept across a variety
of our I/O interfaces.

> ....  OTOH these non-PCI devices you're talking about are
> presumably very specific to PPC embedded chips so maybe it doesn't
> matter so much.

That is always a challenge with the embedded parts.  It is often
very convenient to make the (promper, IMHO) assumption this software
isn't going to be used outside of these parts.

Thanks.

	-- Dan

** Sent via the linuxppc-dev mail list. See http://lists.linuxppc.org/