Subject: How does a driver allocate some uncached memory?
To: None <port-pmax@NetBSD.ORG>
From: Matt Thomas <matt@lkg.dec.com>
List: port-pmax
Date: 03/20/1997 17:56:37
I this device which has a small block of memory (64 bytes) which
get updated asynchronously via DMA. Now I could have driver clean
the block from cache before it reads from the block but it would
be much faster (and cleaner) if I could allocate it and then via
a MI method get an uncached alias of it.
I promise to never-ever free it or reference it via a caching VA.
Ideas?
[I really like machines with coherent caches. Too bad the MIPS
designed aren't coherent.]
--
Matt Thomas Internet: matt@3am-software.com
3am Software Foundry WWW URL: http://www.3am-software.com/bio/matt.html
Westford, MA Disclaimer: I disavow all knowledge of this message