percpu: Remove irqsafe_cpu_xxx variants

We simply say that regular this_cpu use must be safe regardless of
preemption and interrupt state.  That has no material change for x86
and s390 implementations of this_cpu operations.  However, arches that
do not provide their own implementation for this_cpu operations will
now get code generated that disables interrupts instead of preemption.

-tj: This is part of on-going percpu API cleanup.  For detailed
     discussion of the subject, please refer to the following thread.

     http://thread.gmane.org/gmane.linux.kernel/1222078

Signed-off-by: Christoph Lameter <cl@linux.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
LKML-Reference: <alpine.DEB.2.00.1112221154380.11787@router.home>
diff --git a/mm/slub.c b/mm/slub.c
index ed3334d..0011489 100644
--- a/mm/slub.c
+++ b/mm/slub.c
@@ -1978,7 +1978,7 @@
 		page->pobjects = pobjects;
 		page->next = oldpage;
 
-	} while (irqsafe_cpu_cmpxchg(s->cpu_slab->partial, oldpage, page) != oldpage);
+	} while (this_cpu_cmpxchg(s->cpu_slab->partial, oldpage, page) != oldpage);
 	stat(s, CPU_PARTIAL_FREE);
 	return pobjects;
 }
@@ -2304,7 +2304,7 @@
 		 * Since this is without lock semantics the protection is only against
 		 * code executing on this cpu *not* from access by other cpus.
 		 */
-		if (unlikely(!irqsafe_cpu_cmpxchg_double(
+		if (unlikely(!this_cpu_cmpxchg_double(
 				s->cpu_slab->freelist, s->cpu_slab->tid,
 				object, tid,
 				get_freepointer_safe(s, object), next_tid(tid)))) {
@@ -2534,7 +2534,7 @@
 	if (likely(page == c->page)) {
 		set_freepointer(s, object, c->freelist);
 
-		if (unlikely(!irqsafe_cpu_cmpxchg_double(
+		if (unlikely(!this_cpu_cmpxchg_double(
 				s->cpu_slab->freelist, s->cpu_slab->tid,
 				c->freelist, tid,
 				object, next_tid(tid)))) {