pls help-problem with mmap DMA buffer

Hi ,

I get the same problem as in
http://lists.ozlabs.org/pipermail/linuxppc-dev/2009-November/077394.html

posted by Jonathan.

One solution suggested is using get_user_pages(), which give a pointer of
user space buffer to the kernel module to DMA( as I got it)
But the code in teh above link tries to get the kernel buffer pointer in to
the user space. What I want to know is what's wrong/what modifications
should be done to the above code to achieve this? Is this a bad aproach to
access the DMA buffer in user space?

Thanx in advance.