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Subject: Re: pte_offset_map for ppc assumes HIGHPTE
From: Benjamin Herrenschmidt <benh@kernel.crashing.org>
To: Satya <satyakiran@gmail.com>
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Date: Thu, 26 Jul 2007 09:10:15 +1000
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On Wed, 2007-07-25 at 17:16 -0500, Satya wrote:
> hello,
> The implementation of pte_offset_map() for ppc assumes that PTEs are
> kept in highmem (CONFIG_HIGHPTE). There is only one implmentation of
> pte_offset_map() as follows (include/asm-ppc/pgtable.h):
> 
> #define pte_offset_map(dir, addr)               \
>          ((pte_t *) kmap_atomic(pmd_page(*(dir)), KM_PTE0) + pte_index(addr))
> 
> Shouldn't this be made conditional according to CONFIG_HIGHPTE is
> defined or not (as implemented in include/asm-i386/pgtable.h) ?
> 
> the same goes for pte_offset_map_nested and the corresponding unmap functions.

Do we have CONFIG_HIGHMEM without CONFIG_HIGHPTE ? If yes, then indeed,
we should change that. Though I'm not sure I see the point of splitting
those 2 options.

Ben.