powerpc/mm: Only check for _PAGE_PRESENT in set_pte/pmd functions

We want to make sure we don't use these function when updating a pte
or pmd entry that have a valid hpte entry, because these functions
don't invalidate them. So limit the check to _PAGE_PRESENT bit.
Numafault core changes use these functions for updating _PAGE_NUMA bits.
That should be ok because when _PAGE_NUMA is set we can be sure that
hpte entries are not present.

Signed-off-by: Aneesh Kumar K.V <[e-mail]>
Acked-by: Paul Mackerras <[e-mail]>
Signed-off-by: Benjamin Herrenschmidt <[e-mail]>

arch/powerpc/mm/pgtable.c

···
 		pte_t pte)
 {
 #ifdef CONFIG_DEBUG_VM
-	WARN_ON(pte_present(*ptep));
+	WARN_ON(pte_val(*ptep) & _PAGE_PRESENT);
 #endif
 	/* Note: mm->context.id might not yet have been assigned as
 	 * this context might not have been activated yet when this

arch/powerpc/mm/pgtable_64.c

···
 		pmd_t *pmdp, pmd_t pmd)
 {
 #ifdef CONFIG_DEBUG_VM
-	WARN_ON(!pmd_none(*pmdp));
+	WARN_ON(pmd_val(*pmdp) & _PAGE_PRESENT);
 	assert_spin_locked(&mm->page_table_lock);
 	WARN_ON(!pmd_trans_huge(pmd));
 #endif