powerpc/mm/hash: Add hpte_get_old_v and use that instead of opencoding

No functional change

Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>

arch/powerpc/include/asm/book3s/64/mmu-hash.h

@@ -364,6 +364,16 @@ static inline unsigned long hpte_new_to_old_r(unsigned long r)
 	return r & ~HPTE_R_3_0_SSIZE_MASK;
 }
 
+static inline unsigned long hpte_get_old_v(struct hash_pte *hptep)
+{
+	unsigned long hpte_v;
+
+	hpte_v = be64_to_cpu(hptep->v);
+	if (cpu_has_feature(CPU_FTR_ARCH_300))
+		hpte_v = hpte_new_to_old_v(hpte_v, be64_to_cpu(hptep->r));
+	return hpte_v;
+}
+
 /*
  * This function sets the AVPN and L fields of the HPTE  appropriately
  * using the base page size and actual page size.