lkml.org 
[lkml]   [2004]   [Oct]   [22]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
Date
From
SubjectRe: remap_page_range64() for PPC
On Fri, Oct 15, 2004 at 11:46:42PM -0400, Glenn Burkhardt wrote:
>> I'm writing an application to run on a PowerPC with a 2.4 embedded
>> Linux kernel, and I want to make device registers for our custom
>> hardware accessable from user space with mmap(). The physical address
>> of the device is above the 4gb boundary (we attach to the 440's
>> external peripheral bus), so a standard 'remap_page_range()' call
>> won't work.

On Fri, Oct 15, 2004 at 11:32:26PM -0700, Matt Porter wrote:
> This has come up several times on the ppc lists (but since we still
> don't have archives back, nobody can search anyway). I dropped
> 2.4 and 2.5 patches in source.mvista.com:/pub/linuxppc/ a long
> time ago. You just need to update your board-specific fixup routine
> in that version or just make a copy or remap_page_range() into your
> driver and use u64 for the phys address.
> The real fix, of course, is in the -mm tree as remap_pfn_range(),
> I plan to merge 440 io_remap_page_range() support on top of that
> call when it goes into mainline. But that doesn't help you with
> 2.4. :)

It has gone mainline. Glenn Burkhardt's troubles should now be fixed
for all time, unless io_remap_page_range() itself is in question. I'd
like to carry out a similar conversion on io_remap_page_range() so that
it can have similar safety against physical address overflow. There is
one 32-bit architecture where all IO memory is beyond the 4GB boundary,
and a number where at least some crucial portions of it are. This would
then decide how many arguments io_remap_page_range() takes. There are
some difficulties in this (particularly for the architecture[s] it
would benefit most) so I've been punting on this issue thus far.


-- wli
-
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@vger.kernel.org
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/

\
 
 \ /
  Last update: 2005-03-22 14:07    [W:0.054 / U:0.408 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site