Re: [PATCH] powerpc/mm: Implement _PAGE_SPECIAL & pte_special() for 32-bit

From: Kumar Gala
Date: Thu Jul 31 2008 - 15:04:29 EST



On Jul 31, 2008, at 1:48 PM, Kumar Gala wrote:

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>
---
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

Josh,

Can you test this on 44x for me.

thanks

- k
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