Implement _PAGE_SPECIAL and pte_special() for 32-bit powerpc. This bit will
be used by the fast get_user_pages() to differenciate PTEs that correspond
to a valid struct page from special mappings that don't such as IO mappings
obtained via io_remap_pfn_ranges().
We currently only implement this on sub-arch that support SMP or will so
in the future (6xx, 44x, FSL-BookE) and not (8xx, 40x).
Signed-off-by: Kumar Gala <galak@xxxxxxxxxxxxxxxxxxx>
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Nick, do you forsee using _PAGE_SPECIAL for other applications that would
be of interested to non-SMP hw?
We can look at adding it into 8xx and 40x, but was being lazy as I assume
there is no point.
- k