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>

1 files changed, 21 insertions, 0 deletions

diff --git a/arch/powerpc/include/asm/pgtable.h b/arch/powerpc/include/asm/pgtable.h
index 7d6eacf249cf..b60ceb8d86c8 100644
--- 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__ */