On Mon, 2013-10-28 at 15:52 +0530, Bharat Bhushan wrote:
> We need to search linux "pte" to get "pte" attributes for
> setting TLB in KVM.
> This patch defines a linux_pte_lookup() function for same.
>
> Signed-off-by: Bharat Bhushan <bharat.bhushan@xxxxxxxxxxxxx>
> ---
> v1->v2
> -- removed _PAGE_BUSY and _PAGE_PRESENT as suggested by PaulS
> -- Added _PAGE_SPLITTING
>
> arch/powerpc/include/asm/pgtable.h | 27 +++++++++++++++++++++++++++
> 1 files changed, 27 insertions(+), 0 deletions(-)
>
> diff --git a/arch/powerpc/include/asm/pgtable.h b/arch/powerpc/include/asm/pgtable.h
> index 7d6eacf..a7151df 100644
> --- a/arch/powerpc/include/asm/pgtable.h
> +++ b/arch/powerpc/include/asm/pgtable.h
> @@ -223,6 +223,33 @@ extern int gup_hugepte(pte_t *ptep, unsigned long sz, unsigned long addr,
> #endif
> pte_t *find_linux_pte_or_hugepte(pgd_t *pgdir, unsigned long ea,
> unsigned *shift);
> +
> +static inline pte_t lookup_linux_pte(pgd_t *pgdir, unsigned long hva,
> + unsigned long *pte_sizep)
> +{
> + pte_t *ptep;
> + unsigned long ps = *pte_sizep;
> + unsigned int shift;
> +
> + ptep = find_linux_pte_or_hugepte(pgdir, hva, &shift);
> + if (!ptep)
> + return __pte(0);
> + if (shift)
> + *pte_sizep = 1ul << shift;
> + else
> + *pte_sizep = PAGE_SIZE;
> +
> + if (ps > *pte_sizep)
> + return __pte(0);
> +
> +#ifdef CONFIG_TRANSPARENT_HUGEPAGE
> + /* If hugepage and is trans splitting return None */
> + if (unlikely(hugepage && pmd_trans_splitting(pte_pmd(*ptep))))
> + return __pte(0);
> +#endif
> +
> + return pte_val(*ptep);;
> +}
s/;;/;/
I'd still rather see lookup_linux_ptep and then the caller can decide
what to do with it. Currently that CONFIG_TRANSPARENT_HUGEPAGE code
will be completely untested since we don't call this except on booke.
In fact, it doesn't even look like it compiles -- where is "hugepage"
defined?
-Scott
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