4 files changed, 293 insertions, 313 deletions

diff --git a/drivers/xen/events/events_2l.c b/drivers/xen/events/events_2l.c
index b8f2f971c2..e3585330cf 100644
--- a/drivers/xen/events/events_2l.c
+++ b/drivers/xen/events/events_2l.c
@@ -171,11 +171,11 @@ static void evtchn_2l_handle_events(unsigned cpu, struct evtchn_loop_ctrl *ctrl)
 	int i;
 	struct shared_info *s = HYPERVISOR_shared_info;
 	struct vcpu_info *vcpu_info = __this_cpu_read(xen_vcpu);
+	evtchn_port_t evtchn;
 
 	/* Timer interrupt has highest priority. */
-	irq = irq_from_virq(cpu, VIRQ_TIMER);
+	irq = irq_evtchn_from_virq(cpu, VIRQ_TIMER, &evtchn);
 	if (irq != -1) {
-		evtchn_port_t evtchn = evtchn_from_irq(irq);
 		word_idx = evtchn / BITS_PER_LONG;
 		bit_idx = evtchn % BITS_PER_LONG;
 		if (active_evtchns(cpu, s, word_idx) & (1ULL << bit_idx))
@@ -328,9 +328,9 @@ irqreturn_t xen_debug_interrupt(int irq, void *dev_id)
 	for (i = 0; i < EVTCHN_2L_NR_CHANNELS; i++) {
 		if (sync_test_bit(i, BM(sh->evtchn_pending))) {
 			int word_idx = i / BITS_PER_EVTCHN_WORD;
-			printk("  %d: event %d -> irq %d%s%s%s\n",
+			printk("  %d: event %d -> irq %u%s%s%s\n",
 			       cpu_from_evtchn(i), i,
-			       get_evtchn_to_irq(i),
+			       irq_from_evtchn(i),
 			       sync_test_bit(word_idx, BM(&v->evtchn_pending_sel))
 			       ? "" : " l2-clear",
 			       !sync_test_bit(i, BM(sh->evtchn_mask))
diff --git a/drivers/xen/events/events_base.c b/drivers/xen/events/events_base.c
index c50419638a..3b9f080109 100644
--- a/drivers/xen/events/events_base.c
+++ b/drivers/xen/events/events_base.c
@@ -174,7 +174,7 @@ static int **evtchn_to_irq;
 #ifdef CONFIG_X86
 static unsigned long *pirq_eoi_map;
 #endif
-static bool (*pirq_needs_eoi)(unsigned irq);
+static bool (*pirq_needs_eoi)(struct irq_info *info);
 
 #define EVTCHN_ROW(e)  (e / (PAGE_SIZE/sizeof(**evtchn_to_irq)))
 #define EVTCHN_COL(e)  (e % (PAGE_SIZE/sizeof(**evtchn_to_irq)))
@@ -190,7 +190,6 @@ static struct irq_chip xen_lateeoi_chip;
 static struct irq_chip xen_percpu_chip;
 static struct irq_chip xen_pirq_chip;
 static void enable_dynirq(struct irq_data *data);
-static void disable_dynirq(struct irq_data *data);
 
 static DEFINE_PER_CPU(unsigned int, irq_epoch);
 
@@ -248,15 +247,6 @@ static int set_evtchn_to_irq(evtchn_port_t evtchn, unsigned int irq)
 	return 0;
 }
 
-int get_evtchn_to_irq(evtchn_port_t evtchn)
-{
-	if (evtchn >= xen_evtchn_max_channels())
-		return -1;
-	if (evtchn_to_irq[EVTCHN_ROW(evtchn)] == NULL)
-		return -1;
-	return READ_ONCE(evtchn_to_irq[EVTCHN_ROW(evtchn)][EVTCHN_COL(evtchn)]);
-}
-
 /* Get info for IRQ */
 static struct irq_info *info_for_irq(unsigned irq)
 {
@@ -274,6 +264,19 @@ static void set_info_for_irq(unsigned int irq, struct irq_info *info)
 		irq_set_chip_data(irq, info);
 }
 
+static struct irq_info *evtchn_to_info(evtchn_port_t evtchn)
+{
+	int irq;
+
+	if (evtchn >= xen_evtchn_max_channels())
+		return NULL;
+	if (evtchn_to_irq[EVTCHN_ROW(evtchn)] == NULL)
+		return NULL;
+	irq = READ_ONCE(evtchn_to_irq[EVTCHN_ROW(evtchn)][EVTCHN_COL(evtchn)]);
+
+	return (irq < 0) ? NULL : info_for_irq(irq);
+}
+
 /* Per CPU channel accounting */
 static void channels_on_cpu_dec(struct irq_info *info)
 {
@@ -300,6 +303,13 @@ static void channels_on_cpu_inc(struct irq_info *info)
 	info->is_accounted = 1;
 }
 
+static void xen_irq_free_desc(unsigned int irq)
+{
+	/* Legacy IRQ descriptors are managed by the arch. */
+	if (irq >= nr_legacy_irqs())
+		irq_free_desc(irq);
+}
+
 static void delayed_free_irq(struct work_struct *work)
 {
 	struct irq_info *info = container_of(to_rcu_work(work), struct irq_info,
@@ -311,14 +321,11 @@ static void delayed_free_irq(struct work_struct *work)
 
 	kfree(info);
 
-	/* Legacy IRQ descriptors are managed by the arch. */
-	if (irq >= nr_legacy_irqs())
-		irq_free_desc(irq);
+	xen_irq_free_desc(irq);
 }
 
 /* Constructors for packed IRQ information. */
 static int xen_irq_info_common_setup(struct irq_info *info,
-				     unsigned irq,
 				     enum xen_irq_type type,
 				     evtchn_port_t evtchn,
 				     unsigned short cpu)
@@ -328,29 +335,27 @@ static int xen_irq_info_common_setup(struct irq_info *info,
 	BUG_ON(info->type != IRQT_UNBOUND && info->type != type);
 
 	info->type = type;
-	info->irq = irq;
 	info->evtchn = evtchn;
 	info->cpu = cpu;
 	info->mask_reason = EVT_MASK_REASON_EXPLICIT;
 	raw_spin_lock_init(&info->lock);
 
-	ret = set_evtchn_to_irq(evtchn, irq);
+	ret = set_evtchn_to_irq(evtchn, info->irq);
 	if (ret < 0)
 		return ret;
 
-	irq_clear_status_flags(irq, IRQ_NOREQUEST|IRQ_NOAUTOEN);
+	irq_clear_status_flags(info->irq, IRQ_NOREQUEST | IRQ_NOAUTOEN);
 
 	return xen_evtchn_port_setup(evtchn);
 }
 
-static int xen_irq_info_evtchn_setup(unsigned irq,
+static int xen_irq_info_evtchn_setup(struct irq_info *info,
 				     evtchn_port_t evtchn,
 				     struct xenbus_device *dev)
 {
-	struct irq_info *info = info_for_irq(irq);
 	int ret;
 
-	ret = xen_irq_info_common_setup(info, irq, IRQT_EVTCHN, evtchn, 0);
+	ret = xen_irq_info_common_setup(info, IRQT_EVTCHN, evtchn, 0);
 	info->u.interdomain = dev;
 	if (dev)
 		atomic_inc(&dev->event_channels);
@@ -358,50 +363,37 @@ static int xen_irq_info_evtchn_setup(unsigned irq,
 	return ret;
 }
 
-static int xen_irq_info_ipi_setup(unsigned cpu,
-				  unsigned irq,
-				  evtchn_port_t evtchn,
-				  enum ipi_vector ipi)
+static int xen_irq_info_ipi_setup(struct irq_info *info, unsigned int cpu,
+				  evtchn_port_t evtchn, enum ipi_vector ipi)
 {
-	struct irq_info *info = info_for_irq(irq);
-
 	info->u.ipi = ipi;
 
-	per_cpu(ipi_to_irq, cpu)[ipi] = irq;
+	per_cpu(ipi_to_irq, cpu)[ipi] = info->irq;
 	per_cpu(ipi_to_evtchn, cpu)[ipi] = evtchn;
 
-	return xen_irq_info_common_setup(info, irq, IRQT_IPI, evtchn, 0);
+	return xen_irq_info_common_setup(info, IRQT_IPI, evtchn, 0);
 }
 
-static int xen_irq_info_virq_setup(unsigned cpu,
-				   unsigned irq,
-				   evtchn_port_t evtchn,
-				   unsigned virq)
+static int xen_irq_info_virq_setup(struct irq_info *info, unsigned int cpu,
+				   evtchn_port_t evtchn, unsigned int virq)
 {
-	struct irq_info *info = info_for_irq(irq);
-
 	info->u.virq = virq;
 
-	per_cpu(virq_to_irq, cpu)[virq] = irq;
+	per_cpu(virq_to_irq, cpu)[virq] = info->irq;
 
-	return xen_irq_info_common_setup(info, irq, IRQT_VIRQ, evtchn, 0);
+	return xen_irq_info_common_setup(info, IRQT_VIRQ, evtchn, 0);
 }
 
-static int xen_irq_info_pirq_setup(unsigned irq,
-				   evtchn_port_t evtchn,
-				   unsigned pirq,
-				   unsigned gsi,
-				   uint16_t domid,
-				   unsigned char flags)
+static int xen_irq_info_pirq_setup(struct irq_info *info, evtchn_port_t evtchn,
+				   unsigned int pirq, unsigned int gsi,
+				   uint16_t domid, unsigned char flags)
 {
-	struct irq_info *info = info_for_irq(irq);
-
 	info->u.pirq.pirq = pirq;
 	info->u.pirq.gsi = gsi;
 	info->u.pirq.domid = domid;
 	info->u.pirq.flags = flags;
 
-	return xen_irq_info_common_setup(info, irq, IRQT_PIRQ, evtchn, 0);
+	return xen_irq_info_common_setup(info, IRQT_PIRQ, evtchn, 0);
 }
 
 static void xen_irq_info_cleanup(struct irq_info *info)
@@ -415,7 +407,7 @@ static void xen_irq_info_cleanup(struct irq_info *info)
 /*
  * Accessors for packed IRQ information.
  */
-evtchn_port_t evtchn_from_irq(unsigned irq)
+static evtchn_port_t evtchn_from_irq(unsigned int irq)
 {
 	const struct irq_info *info = NULL;
 
@@ -429,64 +421,51 @@ evtchn_port_t evtchn_from_irq(unsigned irq)
 
 unsigned int irq_from_evtchn(evtchn_port_t evtchn)
 {
-	return get_evtchn_to_irq(evtchn);
+	struct irq_info *info = evtchn_to_info(evtchn);
+
+	return info ? info->irq : -1;
 }
 EXPORT_SYMBOL_GPL(irq_from_evtchn);
 
-int irq_from_virq(unsigned int cpu, unsigned int virq)
+int irq_evtchn_from_virq(unsigned int cpu, unsigned int virq,
+			 evtchn_port_t *evtchn)
 {
-	return per_cpu(virq_to_irq, cpu)[virq];
+	int irq = per_cpu(virq_to_irq, cpu)[virq];
+
+	*evtchn = evtchn_from_irq(irq);
+
+	return irq;
 }
 
-static enum ipi_vector ipi_from_irq(unsigned irq)
+static enum ipi_vector ipi_from_irq(struct irq_info *info)
 {
-	struct irq_info *info = info_for_irq(irq);
-
 	BUG_ON(info == NULL);
 	BUG_ON(info->type != IRQT_IPI);
 
 	return info->u.ipi;
 }
 
-static unsigned virq_from_irq(unsigned irq)
+static unsigned int virq_from_irq(struct irq_info *info)
 {
-	struct irq_info *info = info_for_irq(irq);
-
 	BUG_ON(info == NULL);
 	BUG_ON(info->type != IRQT_VIRQ);
 
 	return info->u.virq;
 }
 
-static unsigned pirq_from_irq(unsigned irq)
+static unsigned int pirq_from_irq(struct irq_info *info)
 {
-	struct irq_info *info = info_for_irq(irq);
-
 	BUG_ON(info == NULL);
 	BUG_ON(info->type != IRQT_PIRQ);
 
 	return info->u.pirq.pirq;
 }
 
-static enum xen_irq_type type_from_irq(unsigned irq)
-{
-	return info_for_irq(irq)->type;
-}
-
-static unsigned cpu_from_irq(unsigned irq)
-{
-	return info_for_irq(irq)->cpu;
-}
-
 unsigned int cpu_from_evtchn(evtchn_port_t evtchn)
 {
-	int irq = get_evtchn_to_irq(evtchn);
-	unsigned ret = 0;
-
-	if (irq != -1)
-		ret = cpu_from_irq(irq);
+	struct irq_info *info = evtchn_to_info(evtchn);
 
-	return ret;
+	return info ? info->cpu : 0;
 }
 
 static void do_mask(struct irq_info *info, u8 reason)
@@ -518,36 +497,30 @@ static void do_unmask(struct irq_info *info, u8 reason)
 }
 
 #ifdef CONFIG_X86
-static bool pirq_check_eoi_map(unsigned irq)
+static bool pirq_check_eoi_map(struct irq_info *info)
 {
-	return test_bit(pirq_from_irq(irq), pirq_eoi_map);
+	return test_bit(pirq_from_irq(info), pirq_eoi_map);
 }
 #endif
 
-static bool pirq_needs_eoi_flag(unsigned irq)
+static bool pirq_needs_eoi_flag(struct irq_info *info)
 {
-	struct irq_info *info = info_for_irq(irq);
 	BUG_ON(info->type != IRQT_PIRQ);
 
 	return info->u.pirq.flags & PIRQ_NEEDS_EOI;
 }
 
-static void bind_evtchn_to_cpu(evtchn_port_t evtchn, unsigned int cpu,
+static void bind_evtchn_to_cpu(struct irq_info *info, unsigned int cpu,
 			       bool force_affinity)
 {
-	int irq = get_evtchn_to_irq(evtchn);
-	struct irq_info *info = info_for_irq(irq);
-
-	BUG_ON(irq == -1);
-
 	if (IS_ENABLED(CONFIG_SMP) && force_affinity) {
-		struct irq_data *data = irq_get_irq_data(irq);
+		struct irq_data *data = irq_get_irq_data(info->irq);
 
 		irq_data_update_affinity(data, cpumask_of(cpu));
 		irq_data_update_effective_affinity(data, cpumask_of(cpu));
 	}
 
-	xen_evtchn_port_bind_to_cpu(evtchn, cpu, info->cpu);
+	xen_evtchn_port_bind_to_cpu(info->evtchn, cpu, info->cpu);
 
 	channels_on_cpu_dec(info);
 	info->cpu = cpu;
@@ -737,50 +710,49 @@ void xen_irq_lateeoi(unsigned int irq, unsigned int eoi_flags)
 }
 EXPORT_SYMBOL_GPL(xen_irq_lateeoi);
 
-static void xen_irq_init(unsigned irq)
+static struct irq_info *xen_irq_init(unsigned int irq)
 {
 	struct irq_info *info;
 
 	info = kzalloc(sizeof(*info), GFP_KERNEL);
-	if (info == NULL)
-		panic("Unable to allocate metadata for IRQ%d\n", irq);
+	if (info) {
+		info->irq = irq;
+		info->type = IRQT_UNBOUND;
+		info->refcnt = -1;
+		INIT_RCU_WORK(&info->rwork, delayed_free_irq);
 
-	info->type = IRQT_UNBOUND;
-	info->refcnt = -1;
-	INIT_RCU_WORK(&info->rwork, delayed_free_irq);
+		set_info_for_irq(irq, info);
+		/*
+		 * Interrupt affinity setting can be immediate. No point
+		 * in delaying it until an interrupt is handled.
+		 */
+		irq_set_status_flags(irq, IRQ_MOVE_PCNTXT);
 
-	set_info_for_irq(irq, info);
-	/*
-	 * Interrupt affinity setting can be immediate. No point
-	 * in delaying it until an interrupt is handled.
-	 */
-	irq_set_status_flags(irq, IRQ_MOVE_PCNTXT);
+		INIT_LIST_HEAD(&info->eoi_list);
+		list_add_tail(&info->list, &xen_irq_list_head);
+	}
 
-	INIT_LIST_HEAD(&info->eoi_list);
-	list_add_tail(&info->list, &xen_irq_list_head);
+	return info;
 }
 
-static int __must_check xen_allocate_irqs_dynamic(int nvec)
+static struct irq_info *xen_allocate_irq_dynamic(void)
 {
-	int i, irq = irq_alloc_descs(-1, 0, nvec, -1);
+	int irq = irq_alloc_desc_from(0, -1);
+	struct irq_info *info = NULL;
 
 	if (irq >= 0) {
-		for (i = 0; i < nvec; i++)
-			xen_irq_init(irq + i);
+		info = xen_irq_init(irq);
+		if (!info)
+			xen_irq_free_desc(irq);
 	}
 
-	return irq;
-}
-
-static inline int __must_check xen_allocate_irq_dynamic(void)
-{
-
-	return xen_allocate_irqs_dynamic(1);
+	return info;
 }
 
-static int __must_check xen_allocate_irq_gsi(unsigned gsi)
+static struct irq_info *xen_allocate_irq_gsi(unsigned int gsi)
 {
 	int irq;
+	struct irq_info *info;
 
 	/*
 	 * A PV guest has no concept of a GSI (since it has no ACPI
@@ -797,15 +769,15 @@ static int __must_check xen_allocate_irq_gsi(unsigned gsi)
 	else
 		irq = irq_alloc_desc_at(gsi, -1);
 
-	xen_irq_init(irq);
+	info = xen_irq_init(irq);
+	if (!info)
+		xen_irq_free_desc(irq);
 
-	return irq;
+	return info;
 }
 
-static void xen_free_irq(unsigned irq)
+static void xen_free_irq(struct irq_info *info)
 {
-	struct irq_info *info = info_for_irq(irq);
-
 	if (WARN_ON(!info))
 		return;
 
@@ -826,14 +798,11 @@ static void event_handler_exit(struct irq_info *info)
 	clear_evtchn(info->evtchn);
 }
 
-static void pirq_query_unmask(int irq)
+static void pirq_query_unmask(struct irq_info *info)
 {
 	struct physdev_irq_status_query irq_status;
-	struct irq_info *info = info_for_irq(irq);
 
-	BUG_ON(info->type != IRQT_PIRQ);
-
-	irq_status.irq = pirq_from_irq(irq);
+	irq_status.irq = pirq_from_irq(info);
 	if (HYPERVISOR_physdev_op(PHYSDEVOP_irq_status_query, &irq_status))
 		irq_status.flags = 0;
 
@@ -842,61 +811,81 @@ static void pirq_query_unmask(int irq)
 		info->u.pirq.flags |= PIRQ_NEEDS_EOI;
 }
 
-static void eoi_pirq(struct irq_data *data)
+static void do_eoi_pirq(struct irq_info *info)
 {
-	struct irq_info *info = info_for_irq(data->irq);
-	evtchn_port_t evtchn = info ? info->evtchn : 0;
-	struct physdev_eoi eoi = { .irq = pirq_from_irq(data->irq) };
+	struct physdev_eoi eoi = { .irq = pirq_from_irq(info) };
 	int rc = 0;
 
-	if (!VALID_EVTCHN(evtchn))
+	if (!VALID_EVTCHN(info->evtchn))
 		return;
 
 	event_handler_exit(info);
 
-	if (pirq_needs_eoi(data->irq)) {
+	if (pirq_needs_eoi(info)) {
 		rc = HYPERVISOR_physdev_op(PHYSDEVOP_eoi, &eoi);
 		WARN_ON(rc);
 	}
 }
 
+static void eoi_pirq(struct irq_data *data)
+{
+	struct irq_info *info = info_for_irq(data->irq);
+
+	do_eoi_pirq(info);
+}
+
+static void do_disable_dynirq(struct irq_info *info)
+{
+	if (VALID_EVTCHN(info->evtchn))
+		do_mask(info, EVT_MASK_REASON_EXPLICIT);
+}
+
+static void disable_dynirq(struct irq_data *data)
+{
+	struct irq_info *info = info_for_irq(data->irq);
+
+	if (info)
+		do_disable_dynirq(info);
+}
+
 static void mask_ack_pirq(struct irq_data *data)
 {
-	disable_dynirq(data);
-	eoi_pirq(data);
+	struct irq_info *info = info_for_irq(data->irq);
+
+	if (info) {
+		do_disable_dynirq(info);
+		do_eoi_pirq(info);
+	}
 }
 
-static unsigned int __startup_pirq(unsigned int irq)
+static unsigned int __startup_pirq(struct irq_info *info)
 {
 	struct evtchn_bind_pirq bind_pirq;
-	struct irq_info *info = info_for_irq(irq);
-	evtchn_port_t evtchn = evtchn_from_irq(irq);
+	evtchn_port_t evtchn = info->evtchn;
 	int rc;
 
-	BUG_ON(info->type != IRQT_PIRQ);
-
 	if (VALID_EVTCHN(evtchn))
 		goto out;
 
-	bind_pirq.pirq = pirq_from_irq(irq);
+	bind_pirq.pirq = pirq_from_irq(info);
 	/* NB. We are happy to share unless we are probing. */
 	bind_pirq.flags = info->u.pirq.flags & PIRQ_SHAREABLE ?
 					BIND_PIRQ__WILL_SHARE : 0;
 	rc = HYPERVISOR_event_channel_op(EVTCHNOP_bind_pirq, &bind_pirq);
 	if (rc != 0) {
-		pr_warn("Failed to obtain physical IRQ %d\n", irq);
+		pr_warn("Failed to obtain physical IRQ %d\n", info->irq);
 		return 0;
 	}
 	evtchn = bind_pirq.port;
 
-	pirq_query_unmask(irq);
+	pirq_query_unmask(info);
 
-	rc = set_evtchn_to_irq(evtchn, irq);
+	rc = set_evtchn_to_irq(evtchn, info->irq);
 	if (rc)
 		goto err;
 
 	info->evtchn = evtchn;
-	bind_evtchn_to_cpu(evtchn, 0, false);
+	bind_evtchn_to_cpu(info, 0, false);
 
 	rc = xen_evtchn_port_setup(evtchn);
 	if (rc)
@@ -905,26 +894,28 @@ static unsigned int __startup_pirq(unsigned int irq)
 out:
 	do_unmask(info, EVT_MASK_REASON_EXPLICIT);
 
-	eoi_pirq(irq_get_irq_data(irq));
+	do_eoi_pirq(info);
 
 	return 0;
 
 err:
-	pr_err("irq%d: Failed to set port to irq mapping (%d)\n", irq, rc);
+	pr_err("irq%d: Failed to set port to irq mapping (%d)\n", info->irq,
+	       rc);
 	xen_evtchn_close(evtchn);
 	return 0;
 }
 
 static unsigned int startup_pirq(struct irq_data *data)
 {
-	return __startup_pirq(data->irq);
+	struct irq_info *info = info_for_irq(data->irq);
+
+	return __startup_pirq(info);
 }
 
 static void shutdown_pirq(struct irq_data *data)
 {
-	unsigned int irq = data->irq;
-	struct irq_info *info = info_for_irq(irq);
-	evtchn_port_t evtchn = evtchn_from_irq(irq);
+	struct irq_info *info = info_for_irq(data->irq);
+	evtchn_port_t evtchn = info->evtchn;
 
 	BUG_ON(info->type != IRQT_PIRQ);
 
@@ -932,8 +923,8 @@ static void shutdown_pirq(struct irq_data *data)
 		return;
 
 	do_mask(info, EVT_MASK_REASON_EXPLICIT);
-	xen_evtchn_close(evtchn);
 	xen_irq_info_cleanup(info);
+	xen_evtchn_close(evtchn);
 }
 
 static void enable_pirq(struct irq_data *data)
@@ -962,10 +953,15 @@ int xen_irq_from_gsi(unsigned gsi)
 }
 EXPORT_SYMBOL_GPL(xen_irq_from_gsi);
 
-static void __unbind_from_irq(unsigned int irq)
+static void __unbind_from_irq(struct irq_info *info, unsigned int irq)
 {
-	evtchn_port_t evtchn = evtchn_from_irq(irq);
-	struct irq_info *info = info_for_irq(irq);
+	evtchn_port_t evtchn;
+	bool close_evtchn = false;
+
+	if (!info) {
+		xen_irq_free_desc(irq);
+		return;
+	}
 
 	if (info->refcnt > 0) {
 		info->refcnt--;
@@ -973,20 +969,22 @@ static void __unbind_from_irq(unsigned int irq)
 			return;
 	}
 
+	evtchn = info->evtchn;
+
 	if (VALID_EVTCHN(evtchn)) {
-		unsigned int cpu = cpu_from_irq(irq);
+		unsigned int cpu = info->cpu;
 		struct xenbus_device *dev;
 
 		if (!info->is_static)
-			xen_evtchn_close(evtchn);
+			close_evtchn = true;
 
-		switch (type_from_irq(irq)) {
+		switch (info->type) {
 		case IRQT_VIRQ:
-			per_cpu(virq_to_irq, cpu)[virq_from_irq(irq)] = -1;
+			per_cpu(virq_to_irq, cpu)[virq_from_irq(info)] = -1;
 			break;
 		case IRQT_IPI:
-			per_cpu(ipi_to_irq, cpu)[ipi_from_irq(irq)] = -1;
-			per_cpu(ipi_to_evtchn, cpu)[ipi_from_irq(irq)] = 0;
+			per_cpu(ipi_to_irq, cpu)[ipi_from_irq(info)] = -1;
+			per_cpu(ipi_to_evtchn, cpu)[ipi_from_irq(info)] = 0;
 			break;
 		case IRQT_EVTCHN:
 			dev = info->u.interdomain;
@@ -998,9 +996,12 @@ static void __unbind_from_irq(unsigned int irq)
 		}
 
 		xen_irq_info_cleanup(info);
+
+		if (close_evtchn)
+			xen_evtchn_close(evtchn);
 	}
 
-	xen_free_irq(irq);
+	xen_free_irq(info);
 }
 
 /*
@@ -1016,24 +1017,24 @@ static void __unbind_from_irq(unsigned int irq)
 int xen_bind_pirq_gsi_to_irq(unsigned gsi,
 			     unsigned pirq, int shareable, char *name)
 {
-	int irq;
+	struct irq_info *info;
 	struct physdev_irq irq_op;
 	int ret;
 
 	mutex_lock(&irq_mapping_update_lock);
 
-	irq = xen_irq_from_gsi(gsi);
-	if (irq != -1) {
+	ret = xen_irq_from_gsi(gsi);
+	if (ret != -1) {
 		pr_info("%s: returning irq %d for gsi %u\n",
-			__func__, irq, gsi);
+			__func__, ret, gsi);
 		goto out;
 	}
 
-	irq = xen_allocate_irq_gsi(gsi);
-	if (irq < 0)
+	info = xen_allocate_irq_gsi(gsi);
+	if (!info)
 		goto out;
 
-	irq_op.irq = irq;
+	irq_op.irq = info->irq;
 	irq_op.vector = 0;
 
 	/* Only the privileged domain can do this. For non-priv, the pcifront
@@ -1041,20 +1042,19 @@ int xen_bind_pirq_gsi_to_irq(unsigned gsi,
 	 * this in the priv domain. */
 	if (xen_initial_domain() &&
 	    HYPERVISOR_physdev_op(PHYSDEVOP_alloc_irq_vector, &irq_op)) {
-		xen_free_irq(irq);
-		irq = -ENOSPC;
+		xen_free_irq(info);
+		ret = -ENOSPC;
 		goto out;
 	}
 
-	ret = xen_irq_info_pirq_setup(irq, 0, pirq, gsi, DOMID_SELF,
+	ret = xen_irq_info_pirq_setup(info, 0, pirq, gsi, DOMID_SELF,
 			       shareable ? PIRQ_SHAREABLE : 0);
 	if (ret < 0) {
-		__unbind_from_irq(irq);
-		irq = ret;
+		__unbind_from_irq(info, info->irq);
 		goto out;
 	}
 
-	pirq_query_unmask(irq);
+	pirq_query_unmask(info);
 	/* We try to use the handler with the appropriate semantic for the
 	 * type of interrupt: if the interrupt is an edge triggered
 	 * interrupt we use handle_edge_irq.
@@ -1071,16 +1071,18 @@ int xen_bind_pirq_gsi_to_irq(unsigned gsi,
 	 * is the right choice either way.
 	 */
 	if (shareable)
-		irq_set_chip_and_handler_name(irq, &xen_pirq_chip,
+		irq_set_chip_and_handler_name(info->irq, &xen_pirq_chip,
 				handle_fasteoi_irq, name);
 	else
-		irq_set_chip_and_handler_name(irq, &xen_pirq_chip,
+		irq_set_chip_and_handler_name(info->irq, &xen_pirq_chip,
 				handle_edge_irq, name);
 
+	ret = info->irq;
+
 out:
 	mutex_unlock(&irq_mapping_update_lock);
 
-	return irq;
+	return ret;
 }
 
 #ifdef CONFIG_PCI_MSI
@@ -1102,17 +1104,24 @@ int xen_bind_pirq_msi_to_irq(struct pci_dev *dev, struct msi_desc *msidesc,
 			     int pirq, int nvec, const char *name, domid_t domid)
 {
 	int i, irq, ret;
+	struct irq_info *info;
 
 	mutex_lock(&irq_mapping_update_lock);
 
-	irq = xen_allocate_irqs_dynamic(nvec);
+	irq = irq_alloc_descs(-1, 0, nvec, -1);
 	if (irq < 0)
 		goto out;
 
 	for (i = 0; i < nvec; i++) {
+		info = xen_irq_init(irq + i);
+		if (!info) {
+			ret = -ENOMEM;
+			goto error_irq;
+		}
+
 		irq_set_chip_and_handler_name(irq + i, &xen_pirq_chip, handle_edge_irq, name);
 
-		ret = xen_irq_info_pirq_setup(irq + i, 0, pirq + i, 0, domid,
+		ret = xen_irq_info_pirq_setup(info, 0, pirq + i, 0, domid,
 					      i == 0 ? 0 : PIRQ_MSI_GROUP);
 		if (ret < 0)
 			goto error_irq;
@@ -1124,9 +1133,12 @@ int xen_bind_pirq_msi_to_irq(struct pci_dev *dev, struct msi_desc *msidesc,
 out:
 	mutex_unlock(&irq_mapping_update_lock);
 	return irq;
+
 error_irq:
-	while (nvec--)
-		__unbind_from_irq(irq + nvec);
+	while (nvec--) {
+		info = info_for_irq(irq + nvec);
+		__unbind_from_irq(info, irq + nvec);
+	}
 	mutex_unlock(&irq_mapping_update_lock);
 	return ret;
 }
@@ -1162,67 +1174,45 @@ int xen_destroy_irq(int irq)
 		}
 	}
 
-	xen_free_irq(irq);
+	xen_free_irq(info);
 
 out:
 	mutex_unlock(&irq_mapping_update_lock);
 	return rc;
 }
 
-int xen_irq_from_pirq(unsigned pirq)
-{
-	int irq;
-
-	struct irq_info *info;
-
-	mutex_lock(&irq_mapping_update_lock);
-
-	list_for_each_entry(info, &xen_irq_list_head, list) {
-		if (info->type != IRQT_PIRQ)
-			continue;
-		irq = info->irq;
-		if (info->u.pirq.pirq == pirq)
-			goto out;
-	}
-	irq = -1;
-out:
-	mutex_unlock(&irq_mapping_update_lock);
-
-	return irq;
-}
-
-
 int xen_pirq_from_irq(unsigned irq)
 {
-	return pirq_from_irq(irq);
+	struct irq_info *info = info_for_irq(irq);
+
+	return pirq_from_irq(info);
 }
 EXPORT_SYMBOL_GPL(xen_pirq_from_irq);
 
 static int bind_evtchn_to_irq_chip(evtchn_port_t evtchn, struct irq_chip *chip,
 				   struct xenbus_device *dev)
 {
-	int irq;
-	int ret;
+	int ret = -ENOMEM;
+	struct irq_info *info;
 
 	if (evtchn >= xen_evtchn_max_channels())
 		return -ENOMEM;
 
 	mutex_lock(&irq_mapping_update_lock);
 
-	irq = get_evtchn_to_irq(evtchn);
+	info = evtchn_to_info(evtchn);
 
-	if (irq == -1) {
-		irq = xen_allocate_irq_dynamic();
-		if (irq < 0)
+	if (!info) {
+		info = xen_allocate_irq_dynamic();
+		if (!info)
 			goto out;
 
-		irq_set_chip_and_handler_name(irq, chip,
+		irq_set_chip_and_handler_name(info->irq, chip,
 					      handle_edge_irq, "event");
 
-		ret = xen_irq_info_evtchn_setup(irq, evtchn, dev);
+		ret = xen_irq_info_evtchn_setup(info, evtchn, dev);
 		if (ret < 0) {
-			__unbind_from_irq(irq);
-			irq = ret;
+			__unbind_from_irq(info, info->irq);
 			goto out;
 		}
 		/*
@@ -1232,16 +1222,17 @@ static int bind_evtchn_to_irq_chip(evtchn_port_t evtchn, struct irq_chip *chip,
 		 * affinity setting is not invoked on them so nothing would
 		 * bind the channel.
 		 */
-		bind_evtchn_to_cpu(evtchn, 0, false);
-	} else {
-		struct irq_info *info = info_for_irq(irq);
-		WARN_ON(info == NULL || info->type != IRQT_EVTCHN);
+		bind_evtchn_to_cpu(info, 0, false);
+	} else if (!WARN_ON(info->type != IRQT_EVTCHN)) {
+		info->refcnt++;
 	}
 
+	ret = info->irq;
+
 out:
 	mutex_unlock(&irq_mapping_update_lock);
 
-	return irq;
+	return ret;
 }
 
 int bind_evtchn_to_irq(evtchn_port_t evtchn)
@@ -1260,18 +1251,19 @@ static int bind_ipi_to_irq(unsigned int ipi, unsigned int cpu)
 {
 	struct evtchn_bind_ipi bind_ipi;
 	evtchn_port_t evtchn;
-	int ret, irq;
+	struct irq_info *info;
+	int ret;
 
 	mutex_lock(&irq_mapping_update_lock);
 
-	irq = per_cpu(ipi_to_irq, cpu)[ipi];
+	ret = per_cpu(ipi_to_irq, cpu)[ipi];
 
-	if (irq == -1) {
-		irq = xen_allocate_irq_dynamic();
-		if (irq < 0)
+	if (ret == -1) {
+		info = xen_allocate_irq_dynamic();
+		if (!info)
 			goto out;
 
-		irq_set_chip_and_handler_name(irq, &xen_percpu_chip,
+		irq_set_chip_and_handler_name(info->irq, &xen_percpu_chip,
 					      handle_percpu_irq, "ipi");
 
 		bind_ipi.vcpu = xen_vcpu_nr(cpu);
@@ -1280,25 +1272,25 @@ static int bind_ipi_to_irq(unsigned int ipi, unsigned int cpu)
 			BUG();
 		evtchn = bind_ipi.port;
 
-		ret = xen_irq_info_ipi_setup(cpu, irq, evtchn, ipi);
+		ret = xen_irq_info_ipi_setup(info, cpu, evtchn, ipi);
 		if (ret < 0) {
-			__unbind_from_irq(irq);
-			irq = ret;
+			__unbind_from_irq(info, info->irq);
 			goto out;
 		}
 		/*
 		 * Force the affinity mask to the target CPU so proc shows
 		 * the correct target.
 		 */
-		bind_evtchn_to_cpu(evtchn, cpu, true);
+		bind_evtchn_to_cpu(info, cpu, true);
+		ret = info->irq;
 	} else {
-		struct irq_info *info = info_for_irq(irq);
+		info = info_for_irq(ret);
 		WARN_ON(info == NULL || info->type != IRQT_IPI);
 	}
 
  out:
 	mutex_unlock(&irq_mapping_update_lock);
-	return irq;
+	return ret;
 }
 
 static int bind_interdomain_evtchn_to_irq_chip(struct xenbus_device *dev,
@@ -1366,22 +1358,23 @@ int bind_virq_to_irq(unsigned int virq, unsigned int cpu, bool percpu)
 {
 	struct evtchn_bind_virq bind_virq;
 	evtchn_port_t evtchn = 0;
-	int irq, ret;
+	struct irq_info *info;
+	int ret;
 
 	mutex_lock(&irq_mapping_update_lock);
 
-	irq = per_cpu(virq_to_irq, cpu)[virq];
+	ret = per_cpu(virq_to_irq, cpu)[virq];
 
-	if (irq == -1) {
-		irq = xen_allocate_irq_dynamic();
-		if (irq < 0)
+	if (ret == -1) {
+		info = xen_allocate_irq_dynamic();
+		if (!info)
 			goto out;
 
 		if (percpu)
-			irq_set_chip_and_handler_name(irq, &xen_percpu_chip,
+			irq_set_chip_and_handler_name(info->irq, &xen_percpu_chip,
 						      handle_percpu_irq, "virq");
 		else
-			irq_set_chip_and_handler_name(irq, &xen_dynamic_chip,
+			irq_set_chip_and_handler_name(info->irq, &xen_dynamic_chip,
 						      handle_edge_irq, "virq");
 
 		bind_virq.virq = virq;
@@ -1396,10 +1389,9 @@ int bind_virq_to_irq(unsigned int virq, unsigned int cpu, bool percpu)
 			BUG_ON(ret < 0);
 		}
 
-		ret = xen_irq_info_virq_setup(cpu, irq, evtchn, virq);
+		ret = xen_irq_info_virq_setup(info, cpu, evtchn, virq);
 		if (ret < 0) {
-			__unbind_from_irq(irq);
-			irq = ret;
+			__unbind_from_irq(info, info->irq);
 			goto out;
 		}
 
@@ -1407,22 +1399,26 @@ int bind_virq_to_irq(unsigned int virq, unsigned int cpu, bool percpu)
 		 * Force the affinity mask for percpu interrupts so proc
 		 * shows the correct target.
 		 */
-		bind_evtchn_to_cpu(evtchn, cpu, percpu);
+		bind_evtchn_to_cpu(info, cpu, percpu);
+		ret = info->irq;
 	} else {
-		struct irq_info *info = info_for_irq(irq);
+		info = info_for_irq(ret);
 		WARN_ON(info == NULL || info->type != IRQT_VIRQ);
 	}
 
 out:
 	mutex_unlock(&irq_mapping_update_lock);
 
-	return irq;
+	return ret;
 }
 
 static void unbind_from_irq(unsigned int irq)
 {
+	struct irq_info *info;
+
 	mutex_lock(&irq_mapping_update_lock);
-	__unbind_from_irq(irq);
+	info = info_for_irq(irq);
+	__unbind_from_irq(info, irq);
 	mutex_unlock(&irq_mapping_update_lock);
 }
 
@@ -1573,13 +1569,7 @@ EXPORT_SYMBOL_GPL(xen_set_irq_priority);
 
 int evtchn_make_refcounted(evtchn_port_t evtchn, bool is_static)
 {
-	int irq = get_evtchn_to_irq(evtchn);
-	struct irq_info *info;
-
-	if (irq == -1)
-		return -ENOENT;
-
-	info = info_for_irq(irq);
+	struct irq_info *info = evtchn_to_info(evtchn);
 
 	if (!info)
 		return -ENOENT;
@@ -1595,7 +1585,6 @@ EXPORT_SYMBOL_GPL(evtchn_make_refcounted);
 
 int evtchn_get(evtchn_port_t evtchn)
 {
-	int irq;
 	struct irq_info *info;
 	int err = -ENOENT;
 
@@ -1604,11 +1593,7 @@ int evtchn_get(evtchn_port_t evtchn)
 
 	mutex_lock(&irq_mapping_update_lock);
 
-	irq = get_evtchn_to_irq(evtchn);
-	if (irq == -1)
-		goto done;
-
-	info = info_for_irq(irq);
+	info = evtchn_to_info(evtchn);
 
 	if (!info)
 		goto done;
@@ -1628,10 +1613,11 @@ EXPORT_SYMBOL_GPL(evtchn_get);
 
 void evtchn_put(evtchn_port_t evtchn)
 {
-	int irq = get_evtchn_to_irq(evtchn);
-	if (WARN_ON(irq == -1))
+	struct irq_info *info = evtchn_to_info(evtchn);
+
+	if (WARN_ON(!info))
 		return;
-	unbind_from_irq(irq);
+	unbind_from_irq(info->irq);
 }
 EXPORT_SYMBOL_GPL(evtchn_put);
 
@@ -1661,12 +1647,10 @@ struct evtchn_loop_ctrl {
 
 void handle_irq_for_port(evtchn_port_t port, struct evtchn_loop_ctrl *ctrl)
 {
-	int irq;
-	struct irq_info *info;
+	struct irq_info *info = evtchn_to_info(port);
 	struct xenbus_device *dev;
 
-	irq = get_evtchn_to_irq(port);
-	if (irq == -1)
+	if (!info)
 		return;
 
 	/*
@@ -1691,7 +1675,6 @@ void handle_irq_for_port(evtchn_port_t port, struct evtchn_loop_ctrl *ctrl)
 		}
 	}
 
-	info = info_for_irq(irq);
 	if (xchg_acquire(&info->is_active, 1))
 		return;
 
@@ -1705,7 +1688,7 @@ void handle_irq_for_port(evtchn_port_t port, struct evtchn_loop_ctrl *ctrl)
 		info->eoi_time = get_jiffies_64() + event_eoi_delay;
 	}
 
-	generic_handle_irq(irq);
+	generic_handle_irq(info->irq);
 }
 
 int xen_evtchn_do_upcall(void)
@@ -1763,16 +1746,17 @@ void rebind_evtchn_irq(evtchn_port_t evtchn, int irq)
 	mutex_lock(&irq_mapping_update_lock);
 
 	/* After resume the irq<->evtchn mappings are all cleared out */
-	BUG_ON(get_evtchn_to_irq(evtchn) != -1);
+	BUG_ON(evtchn_to_info(evtchn));
 	/* Expect irq to have been bound before,
 	   so there should be a proper type */
 	BUG_ON(info->type == IRQT_UNBOUND);
 
-	(void)xen_irq_info_evtchn_setup(irq, evtchn, NULL);
+	info->irq = irq;
+	(void)xen_irq_info_evtchn_setup(info, evtchn, NULL);
 
 	mutex_unlock(&irq_mapping_update_lock);
 
-	bind_evtchn_to_cpu(evtchn, info->cpu, false);
+	bind_evtchn_to_cpu(info, info->cpu, false);
 
 	/* Unmask the event channel. */
 	enable_irq(irq);
@@ -1806,7 +1790,7 @@ static int xen_rebind_evtchn_to_cpu(struct irq_info *info, unsigned int tcpu)
 	 * it, but don't do the xenlinux-level rebind in that case.
 	 */
 	if (HYPERVISOR_event_channel_op(EVTCHNOP_bind_vcpu, &bind_vcpu) >= 0)
-		bind_evtchn_to_cpu(evtchn, tcpu, false);
+		bind_evtchn_to_cpu(info, tcpu, false);
 
 	do_unmask(info, EVT_MASK_REASON_TEMPORARY);
 
@@ -1863,28 +1847,30 @@ static void enable_dynirq(struct irq_data *data)
 		do_unmask(info, EVT_MASK_REASON_EXPLICIT);
 }
 
-static void disable_dynirq(struct irq_data *data)
+static void do_ack_dynirq(struct irq_info *info)
 {
-	struct irq_info *info = info_for_irq(data->irq);
-	evtchn_port_t evtchn = info ? info->evtchn : 0;
+	evtchn_port_t evtchn = info->evtchn;
 
 	if (VALID_EVTCHN(evtchn))
-		do_mask(info, EVT_MASK_REASON_EXPLICIT);
+		event_handler_exit(info);
 }
 
 static void ack_dynirq(struct irq_data *data)
 {
 	struct irq_info *info = info_for_irq(data->irq);
-	evtchn_port_t evtchn = info ? info->evtchn : 0;
 
-	if (VALID_EVTCHN(evtchn))
-		event_handler_exit(info);
+	if (info)
+		do_ack_dynirq(info);
 }
 
 static void mask_ack_dynirq(struct irq_data *data)
 {
-	disable_dynirq(data);
-	ack_dynirq(data);
+	struct irq_info *info = info_for_irq(data->irq);
+
+	if (info) {
+		do_disable_dynirq(info);
+		do_ack_dynirq(info);
+	}
 }
 
 static void lateeoi_ack_dynirq(struct irq_data *data)
@@ -1957,13 +1943,13 @@ static void restore_pirqs(void)
 		if (rc) {
 			pr_warn("xen map irq failed gsi=%d irq=%d pirq=%d rc=%d\n",
 				gsi, irq, pirq, rc);
-			xen_free_irq(irq);
+			xen_free_irq(info);
 			continue;
 		}
 
 		printk(KERN_DEBUG "xen: --> irq=%d, pirq=%d\n", irq, map_irq.pirq);
 
-		__startup_pirq(irq);
+		__startup_pirq(info);
 	}
 }
 
@@ -1971,13 +1957,15 @@ static void restore_cpu_virqs(unsigned int cpu)
 {
 	struct evtchn_bind_virq bind_virq;
 	evtchn_port_t evtchn;
+	struct irq_info *info;
 	int virq, irq;
 
 	for (virq = 0; virq < NR_VIRQS; virq++) {
 		if ((irq = per_cpu(virq_to_irq, cpu)[virq]) == -1)
 			continue;
+		info = info_for_irq(irq);
 
-		BUG_ON(virq_from_irq(irq) != virq);
+		BUG_ON(virq_from_irq(info) != virq);
 
 		/* Get a new binding from Xen. */
 		bind_virq.virq = virq;
@@ -1988,9 +1976,9 @@ static void restore_cpu_virqs(unsigned int cpu)
 		evtchn = bind_virq.port;
 
 		/* Record the new mapping. */
-		(void)xen_irq_info_virq_setup(cpu, irq, evtchn, virq);
+		xen_irq_info_virq_setup(info, cpu, evtchn, virq);
 		/* The affinity mask is still valid */
-		bind_evtchn_to_cpu(evtchn, cpu, false);
+		bind_evtchn_to_cpu(info, cpu, false);
 	}
 }
 
@@ -1998,13 +1986,15 @@ static void restore_cpu_ipis(unsigned int cpu)
 {
 	struct evtchn_bind_ipi bind_ipi;
 	evtchn_port_t evtchn;
+	struct irq_info *info;
 	int ipi, irq;
 
 	for (ipi = 0; ipi < XEN_NR_IPIS; ipi++) {
 		if ((irq = per_cpu(ipi_to_irq, cpu)[ipi]) == -1)
 			continue;
+		info = info_for_irq(irq);
 
-		BUG_ON(ipi_from_irq(irq) != ipi);
+		BUG_ON(ipi_from_irq(info) != ipi);
 
 		/* Get a new binding from Xen. */
 		bind_ipi.vcpu = xen_vcpu_nr(cpu);
@@ -2014,9 +2004,9 @@ static void restore_cpu_ipis(unsigned int cpu)
 		evtchn = bind_ipi.port;
 
 		/* Record the new mapping. */
-		(void)xen_irq_info_ipi_setup(cpu, irq, evtchn, ipi);
+		xen_irq_info_ipi_setup(info, cpu, evtchn, ipi);
 		/* The affinity mask is still valid */
-		bind_evtchn_to_cpu(evtchn, cpu, false);
+		bind_evtchn_to_cpu(info, cpu, false);
 	}
 }
 
@@ -2030,13 +2020,6 @@ void xen_clear_irq_pending(int irq)
 		event_handler_exit(info);
 }
 EXPORT_SYMBOL(xen_clear_irq_pending);
-void xen_set_irq_pending(int irq)
-{
-	evtchn_port_t evtchn = evtchn_from_irq(irq);
-
-	if (VALID_EVTCHN(evtchn))
-		set_evtchn(evtchn);
-}
 
 bool xen_test_irq_pending(int irq)
 {
diff --git a/drivers/xen/events/events_fifo.c b/drivers/xen/events/events_fifo.c
index ad9fe51d3f..655775db7c 100644
--- a/drivers/xen/events/events_fifo.c
+++ b/drivers/xen/events/events_fifo.c
@@ -226,21 +226,20 @@ static bool evtchn_fifo_is_masked(evtchn_port_t port)
  */
 static bool clear_masked_cond(volatile event_word_t *word)
 {
-	event_word_t new, old, w;
+	event_word_t new, old;
 
-	w = *word;
+	old = *word;
 
 	do {
-		if (!(w & (1 << EVTCHN_FIFO_MASKED)))
+		if (!(old & (1 << EVTCHN_FIFO_MASKED)))
 			return true;
 
-		if (w & (1 << EVTCHN_FIFO_PENDING))
+		if (old & (1 << EVTCHN_FIFO_PENDING))
 			return false;
 
-		old = w & ~(1 << EVTCHN_FIFO_BUSY);
+		old = old & ~(1 << EVTCHN_FIFO_BUSY);
 		new = old & ~(1 << EVTCHN_FIFO_MASKED);
-		w = sync_cmpxchg(word, old, new);
-	} while (w != old);
+	} while (!sync_try_cmpxchg(word, &old, new));
 
 	return true;
 }
@@ -259,17 +258,16 @@ static void evtchn_fifo_unmask(evtchn_port_t port)
 
 static uint32_t clear_linked(volatile event_word_t *word)
 {
-	event_word_t new, old, w;
+	event_word_t new, old;
 
-	w = *word;
+	old = *word;
 
 	do {
-		old = w;
-		new = (w & ~((1 << EVTCHN_FIFO_LINKED)
-			     | EVTCHN_FIFO_LINK_MASK));
-	} while ((w = sync_cmpxchg(word, old, new)) != old);
+		new = (old & ~((1 << EVTCHN_FIFO_LINKED)
+			       | EVTCHN_FIFO_LINK_MASK));
+	} while (!sync_try_cmpxchg(word, &old, new));
 
-	return w & EVTCHN_FIFO_LINK_MASK;
+	return old & EVTCHN_FIFO_LINK_MASK;
 }
 
 static void consume_one_event(unsigned cpu, struct evtchn_loop_ctrl *ctrl,
diff --git a/drivers/xen/events/events_internal.h b/drivers/xen/events/events_internal.h
index 4d3398eff9..19ae31695e 100644
--- a/drivers/xen/events/events_internal.h
+++ b/drivers/xen/events/events_internal.h
@@ -33,7 +33,6 @@ struct evtchn_ops {
 
 extern const struct evtchn_ops *evtchn_ops;
 
-int get_evtchn_to_irq(evtchn_port_t evtchn);
 void handle_irq_for_port(evtchn_port_t port, struct evtchn_loop_ctrl *ctrl);
 
 unsigned int cpu_from_evtchn(evtchn_port_t evtchn);