Re: pgprot_writecombine & shub 1.x

David Mosberger
2005-01-19T18:04:55Z

>>>>> On Wed, 19 Jan 2005 09:56:59 -0800, Jesse Barnes <jbarnes@sgi.com> said:

Jesse> On Wednesday, January 19, 2005 9:53 am, David Mosberger
Jesse> wrote:
>> I'm still not clear which case you're concerned about: mapping
>> I/O memory with WC or mapping real memory with WC. For the
>> latter, I think we may need an API to allocate memory that can be
>> mapped WC (if possible at all).

Jesse> Oh, I thought I said that in the first message, I'm talking
Jesse> about I/O memory here.

OK, thanks for clarifying.

Jesse> In any event though, we shouldn't be mapping anything with
Jesse> the WC attribute that the EFI memory map doesn't allow.

Adding new routines for supporting this sounds reasonable, but I think
it needs to be added to linux/efi.h, since EFI isn't ia64-specific.

Jesse> And yes, we probably do need a special allocator for mapping
Jesse> regular memory with WC or UC attributes to avoid mapping the
Jesse> same region with different attributes.

OK, sounds like we're in violent agreement.

--david