Re: allocating uncachable memory

On Fri, 25 Aug 2000, Dan Malek wrote:

quoted

question again: How can I get an alias mapping (with _PAGE_NO_CACHE |
_PAGE_GUARDED) of some already mapped pages.

There isn't anything generic right now.  A few of us are working on
a solution, as there are other processors affected (IBM 4xx) as well.
If you look at the uart or Ethernet drivers, you will notice they
allocate pages of memory, track down the PTEs and set the attributes
directly.  You can use that as an example.

Don't forget that managing the caches in software (via flushes and
invalidates) could actually provide better performance for data
transfers due to the cache bursting available when caches are enabled.

Yeah, that's what i do currently. But I had to write an
invalidate_dcache_range() first. I used the code of
flush_dcache_range() and replaced dcbst by dcbi. Now it
seems to work. Thanks for this hint, Dan.

ron


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