xen: Use this_cpu_ops

Use this_cpu_ops to reduce code size and simplify things in various places.

V3->V4:
	Move instance of this_cpu_inc_return to a later patchset so that
	this patch can be applied without infrastructure changes.

Cc: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com>
Acked-by: H. Peter Anvin <hpa@zytor.com>
Signed-off-by: Christoph Lameter <cl@linux.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
diff --git a/arch/x86/xen/spinlock.c b/arch/x86/xen/spinlock.c
index 23e061b..cc9b1e1 100644
--- a/arch/x86/xen/spinlock.c
+++ b/arch/x86/xen/spinlock.c
@@ -159,8 +159,8 @@
 {
 	struct xen_spinlock *prev;
 
-	prev = __get_cpu_var(lock_spinners);
-	__get_cpu_var(lock_spinners) = xl;
+	prev = __this_cpu_read(lock_spinners);
+	__this_cpu_write(lock_spinners, xl);
 
 	wmb();			/* set lock of interest before count */
 
@@ -179,14 +179,14 @@
 	asm(LOCK_PREFIX " decw %0"
 	    : "+m" (xl->spinners) : : "memory");
 	wmb();			/* decrement count before restoring lock */
-	__get_cpu_var(lock_spinners) = prev;
+	__this_cpu_write(lock_spinners, prev);
 }
 
 static noinline int xen_spin_lock_slow(struct arch_spinlock *lock, bool irq_enable)
 {
 	struct xen_spinlock *xl = (struct xen_spinlock *)lock;
 	struct xen_spinlock *prev;
-	int irq = __get_cpu_var(lock_kicker_irq);
+	int irq = __this_cpu_read(lock_kicker_irq);
 	int ret;
 	u64 start;