On Wed, Feb 05, 2014 at 07:55:45PM +0000, Marc Zyngier wrote:
> The default pmd_addr_end macro uses an unsigned long to represent
> the VA. When used with KVM and stage-2 translation, the VA is
> actually an IPA, which is up to 40 bits. This also affect the
> SMMU driver, which also deals with stage-2 translation.
>
> Instead, provide an implementation that can cope with larger VAs
> by using a u64 instead. This version will overload the default
> one provided in include/asm-generic/pgtable.h.
>
> Signed-off-by: Marc Zyngier <marc.zyngier@xxxxxxx>
> ---
> arch/arm/include/asm/pgtable-3level.h | 5 +++++
> 1 file changed, 5 insertions(+)
>
> diff --git a/arch/arm/include/asm/pgtable-3level.h b/arch/arm/include/asm/pgtable-3level.h
> index 03243f7..594867b 100644
> --- a/arch/arm/include/asm/pgtable-3level.h
> +++ b/arch/arm/include/asm/pgtable-3level.h
> @@ -262,6 +262,11 @@ static inline int has_transparent_hugepage(void)
> return 1;
> }
>
> +#define pmd_addr_end(addr, end) \
> +({ u64 __boundary = ((addr) + PMD_SIZE) & PMD_MASK; \
> + (__boundary - 1 < (end) - 1)? __boundary: (end); \
> +})
I see why you need this but it affects all the other uses of
pmd_addr_end() with 32-bit VA. It would be slight performance, I don't
think it's noticeable.
A different approach could be something like (untested):
#define pmd_addr_end(addr, end) \
({ __typeof__(addr) __boundary = ...
...
})
What about the pgd_addr_end(), do we need this or it's not used by KVM?
--
Catalin
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