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>

arch/x86/xen/enlighten.c

@@ -574,8 +574,8 @@ static void xen_write_idt_entry(gate_desc *dt, int entrynum, const gate_desc *g)
 
 	preempt_disable();
 
-	start = __get_cpu_var(idt_desc).address;
-	end = start + __get_cpu_var(idt_desc).size + 1;
+	start = __this_cpu_read(idt_desc.address);
+	end = start + __this_cpu_read(idt_desc.size) + 1;
 
 	xen_mc_flush();
 

arch/x86/xen/multicalls.h

@@ -22,7 +22,7 @@ static inline void xen_mc_batch(void)
 	unsigned long flags;
 	/* need to disable interrupts until this entry is complete */
 	local_irq_save(flags);
-	__get_cpu_var(xen_mc_irq_flags) = flags;
+	__this_cpu_write(xen_mc_irq_flags, flags);
 }
 
 static inline struct multicall_space xen_mc_entry(size_t args)

arch/x86/xen/spinlock.c

@@ -159,8 +159,8 @@ static inline struct xen_spinlock *spinning_lock(struct xen_spinlock *xl)
 {
 	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 @@ static inline void unspinning_lock(struct xen_spinlock *xl, struct xen_spinlock
 	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;
 

arch/x86/xen/time.c

@@ -135,24 +135,24 @@ static void do_stolen_accounting(void)
 
 	/* Add the appropriate number of ticks of stolen time,
 	   including any left-overs from last time. */
-	stolen = runnable + offline + __get_cpu_var(xen_residual_stolen);
+	stolen = runnable + offline + __this_cpu_read(xen_residual_stolen);
 
 	if (stolen < 0)
 		stolen = 0;
 
 	ticks = iter_div_u64_rem(stolen, NS_PER_TICK, &stolen);
-	__get_cpu_var(xen_residual_stolen) = stolen;
+	__this_cpu_write(xen_residual_stolen, stolen);
 	account_steal_ticks(ticks);
 
 	/* Add the appropriate number of ticks of blocked time,
 	   including any left-overs from last time. */
-	blocked += __get_cpu_var(xen_residual_blocked);
+	blocked += __this_cpu_read(xen_residual_blocked);
 
 	if (blocked < 0)
 		blocked = 0;
 
 	ticks = iter_div_u64_rem(blocked, NS_PER_TICK, &blocked);
-	__get_cpu_var(xen_residual_blocked) = blocked;
+	__this_cpu_write(xen_residual_blocked, blocked);
 	account_idle_ticks(ticks);
 }
 

drivers/xen/events.c

@@ -355,7 +355,7 @@ static void unmask_evtchn(int port)
 		struct evtchn_unmask unmask = { .port = port };
 		(void)HYPERVISOR_event_channel_op(EVTCHNOP_unmask, &unmask);
 	} else {
-		struct vcpu_info *vcpu_info = __get_cpu_var(xen_vcpu);
+		struct vcpu_info *vcpu_info = __this_cpu_read(xen_vcpu);
 
 		sync_clear_bit(port, &s->evtchn_mask[0]);
 
@@ -1101,7 +1101,7 @@ static void __xen_evtchn_do_upcall(void)
 {
 	int cpu = get_cpu();
 	struct shared_info *s = HYPERVISOR_shared_info;
-	struct vcpu_info *vcpu_info = __get_cpu_var(xen_vcpu);
+	struct vcpu_info *vcpu_info = __this_cpu_read(xen_vcpu);
  	unsigned count;
 
 	do {
@@ -1141,8 +1141,8 @@ static void __xen_evtchn_do_upcall(void)
 
 		BUG_ON(!irqs_disabled());
 
-		count = __get_cpu_var(xed_nesting_count);
-		__get_cpu_var(xed_nesting_count) = 0;
+		count = __this_cpu_read(xed_nesting_count);
+		__this_cpu_write(xed_nesting_count, 0);
 	} while (count != 1 || vcpu_info->evtchn_upcall_pending);
 
 out: