RE: DPRAM driver on 440gp

Given that the physical address has already been mapped, via
ioremap64(), do I need remap_page_range()?  Does anyone have any ideas
on what the mmap file_op for this driver would look like?  Do I even
need mmap() or should I just use an ioctl to return the pointer I've
already got to the user?

The ioctl won't do because the virtual address returned by the ioremap64
is not valid in process context. You could remap it through mmap file_op,
but why bother?
Rem: reading ioremap64 and drivers/char/mem.c is very instructive.

Since you're accessing your DPRAM guarded/uncached, you may simply
map it both in kernel with ioremap64 and in userland with mmap64
of /dev/mem.

For more information, search the archive (or DENX PPC FAQ) on userland
mapping of physical memory.


Regards,
Stephane

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