kvm: powerpc: define a linux pte lookup function

We need to search linux "pte" to get "pte" attributes for setting TLB in KVM.
This patch defines a lookup_linux_ptep() function which returns pte pointer.

Signed-off-by: Bharat Bhushan <bharat.bhushan@freescale.com>
Reviewed-by: Scott Wood <scottwood@freescale.com>
Signed-off-by: Alexander Graf <agraf@suse.de>

diff --git a/arch/powerpc/include/asm/pgtable.h b/arch/powerpc/include/asm/pgtable.h
index 7d6eacf..b60ceb8 100644 (file)
--- a/arch/powerpc/include/asm/pgtable.h
+++ b/arch/powerpc/include/asm/pgtable.h
@@ -223,6 +223,27 @@ 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_ptep(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 NULL;
+       if (shift)
+               *pte_sizep = 1ul << shift;
+       else
+               *pte_sizep = PAGE_SIZE;
+
+       if (ps > *pte_sizep)
+               return NULL;
+
+       return ptep;
+}
 #endif /* __ASSEMBLY__ */
 
 #endif /* __KERNEL__ */