ppc64: move permissions check outside of hash table lock

arch/ppc64/kernel/htab.c

@@ -780,7 +780,6 @@ void hpte_init_pSeries(void)
  */
 int hash_page(unsigned long ea, unsigned long access)
 {
-	int rc = 1;
 	void * pgdir = NULL;
 	unsigned long va, vsid, vpn;
 	unsigned long newpp, hash_ind, prpn;
@@ -856,6 +855,16 @@ int hash_page(unsigned long ea, unsigned long access)
 		return 1;
 	}
 
+	/*
+	 * Check the user's access rights to the page.  If access should be
+	 * prevented then send the problem up to do_page_fault.
+	 */
+	access |= _PAGE_PRESENT;
+	if (access & ~(pte_val(*ptep))) {
+		spin_unlock(&mm->page_table_lock);
+		return 1;
+	}
+
 	/*
 	 * Acquire the hash table lock to guarantee that the linux
 	 * pte we fetch will not change
@@ -890,13 +899,8 @@ int hash_page(unsigned long ea, unsigned long access)
  *	This case is always an error and is not dealt with further here.
  * 5. This is a Kernel address (0xC---) for which there is no page directory.
  *	There is no HPTE for this page.
-
- * Check the user's access rights to the page.  If access should be prevented
- * then send the problem up to do_page_fault.
  */
 
-	access |= _PAGE_PRESENT;
-	if ( 0 == ( access & ~(pte_val(old_pte)) ) ) {
 	/*
 	 * Check if pte might have an hpte, but we have
 	 * no slot information
@@ -995,13 +999,9 @@ int hash_page(unsigned long ea, unsigned long access)
 
 	}
 
-		/* Indicate success */
-		rc = 0;
-	}		
-
 	spin_unlock(&hash_table_lock);
 	spin_unlock(&mm->page_table_lock);
-	return rc;
+	return 0;
 }
 
 void flush_hash_page(unsigned long context, unsigned long ea, pte_t pte)