Regarding consistent_alloc

Matt Porter porter at cox.net
Sat Dec 7 02:59:09 EST 2002


On Fri, Dec 06, 2002 at 03:25:48PM +0100, Joakim Tjernlund wrote:
> If you implement the performance improvement I suggested earlier, I don't think
> you need them. Another thing with consistent_xxx() is that you can not use
> __pa() and __va() on addresses returned by the consistent_alloc et. al.

Um, well if you are doing a consistent_alloc() then surely you are
keeping the dma_handle around which is your physical address.  If you
want the kernel virtual address then you can apply __va to that.  So,
you have the cache inhibited mapping in vmalloc space returned to you,
the physical address provided in dma_handle, and a kernel virtual address
that can be trivially generated.

Regards,
--
Matt Porter
porter at cox.net
This is Linux Country. On a quiet night, you can hear Windows reboot.

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