diff mbox series

[v2] xen: Use evtchn_type_t as a type for event channels

Message ID 20200307134322.GA27756@kbp1-lhp-F74019 (mailing list archive)
State New, archived
Headers show
Series [v2] xen: Use evtchn_type_t as a type for event channels | expand

Commit Message

Yan Yankovskyi March 7, 2020, 1:43 p.m. UTC 
Make event channel functions pass event channel port using
evtchn_port_t type. It eliminates signed <-> unsigned conversion.

Signed-off-by: Yan Yankovskyi <yyankovskyi@gmail.com>
---
 drivers/xen/events/events_2l.c        | 16 +++---
 drivers/xen/events/events_base.c      | 83 ++++++++++++++-------------
 drivers/xen/events/events_fifo.c      | 22 +++----
 drivers/xen/events/events_internal.h  | 30 +++++-----
 drivers/xen/evtchn.c                  | 13 +++--
 drivers/xen/pvcalls-back.c            |  5 +-
 drivers/xen/xen-pciback/xenbus.c      |  7 ++-
 drivers/xen/xen-scsiback.c            |  3 +-
 drivers/xen/xenbus/xenbus_client.c    |  6 +-
 include/xen/events.h                  | 20 +++----
 include/xen/interface/event_channel.h |  2 +-
 include/xen/xenbus.h                  |  4 +-
 12 files changed, 109 insertions(+), 102 deletions(-)

Comments

Boris Ostrovsky March 7, 2020, 7:41 p.m. UTC | #1 
On 3/7/20 8:43 AM, Yan Yankovskyi wrote:
> Make event channel functions pass event channel port using
> evtchn_port_t type. It eliminates signed <-> unsigned conversion.
>


>  static int find_virq(unsigned int virq, unsigned int cpu)
>  {
>  	struct evtchn_status status;
> -	int port, rc = -ENOENT;
> +	evtchn_port_t port;
> +	int rc = -ENOENT;
>  
>  	memset(&status, 0, sizeof(status));
>  	for (port = 0; port < xen_evtchn_max_channels(); port++) {
> @@ -962,7 +963,8 @@ EXPORT_SYMBOL_GPL(xen_evtchn_nr_channels);
>  int bind_virq_to_irq(unsigned int virq, unsigned int cpu, bool percpu)
>  {
>  	struct evtchn_bind_virq bind_virq;
> -	int evtchn, irq, ret;
> +	evtchn_port_t evtchn = xen_evtchn_max_channels();
> +	int irq, ret;
>  
>  	mutex_lock(&irq_mapping_update_lock);
>  
> @@ -990,7 +992,6 @@ int bind_virq_to_irq(unsigned int virq, unsigned int cpu, bool percpu)
>  			if (ret == -EEXIST)
>  				ret = find_virq(virq, cpu);
>  			BUG_ON(ret < 0);
> -			evtchn = ret;


This looks suspicious. What would you be passing to
xen_irq_info_virq_setup() below?

I also think that, given that this patch is trying to get types in
order, find_virq() will need more changes: it is supposed to return
evtchn_port_t. But then it also wants to return a (signed) error.

>  		}
>  
>  		ret = xen_irq_info_virq_setup(cpu, irq, evtchn, virq);
> @@ -1019,7 +1020,7 @@ static void unbind_from_irq(unsigned int irq)
>  	mutex_unlock(&irq_mapping_update_lock);
>  }
>  



> --- a/drivers/xen/xenbus/xenbus_client.c
> +++ b/drivers/xen/xenbus/xenbus_client.c
> @@ -391,7 +391,7 @@ EXPORT_SYMBOL_GPL(xenbus_grant_ring);
>   * error, the device will switch to XenbusStateClosing, and the error will be
>   * saved in the store.
>   */
> -int xenbus_alloc_evtchn(struct xenbus_device *dev, int *port)
> +int xenbus_alloc_evtchn(struct xenbus_device *dev, evtchn_port_t *port)

Right. But then why is the declaration in include/xen/xenbus.h (at the
very end of the patch) different?

>  {
>  	struct evtchn_alloc_unbound alloc_unbound;
>  	int err;
> @@ -414,7 +414,7 @@ EXPORT_SYMBOL_GPL(xenbus_alloc_evtchn);
>  /**
>   * Free an existing event channel. Returns 0 on success or -errno on error.
>   */
> -int xenbus_free_evtchn(struct xenbus_device *dev, int port)
> +int xenbus_free_evtchn(struct xenbus_device *dev, evtchn_port_t port)

Here too.

>  {
>  	struct evtchn_close close;
>  	int err;
> @@ -423,7 +423,7 @@ int xenbus_free_evtchn(struct xenbus_device *dev, int port)

And why not here, especially since you updated format?

>  
>  	err = HYPERVISOR_event_channel_op(EVTCHNOP_close, &close);
>  	if (err)
> -		xenbus_dev_error(dev, err, "freeing event channel %d", port);
> +		xenbus_dev_error(dev, err, "freeing event channel %u", port);
>  
>  	return err;
>  }



>  
> diff --git a/include/xen/interface/event_channel.h b/include/xen/interface/event_channel.h
> index 45650c9a06d5..cf80e338fbb0 100644
> --- a/include/xen/interface/event_channel.h
> +++ b/include/xen/interface/event_channel.h
> @@ -220,7 +220,7 @@ struct evtchn_expand_array {
>  #define EVTCHNOP_set_priority    13
>  struct evtchn_set_priority {
>  	/* IN parameters. */
> -	uint32_t port;
> +	evtchn_port_t port;

This definition comes from Xen so I think it needs to be fixed there first.

>  	uint32_t priority;
>  };
>  
> diff --git a/include/xen/xenbus.h b/include/xen/xenbus.h
> index 89a889585ba0..4f35216064ba 100644
> --- a/include/xen/xenbus.h
> +++ b/include/xen/xenbus.h
> @@ -218,8 +218,8 @@ int xenbus_unmap_ring(struct xenbus_device *dev,
>  		      grant_handle_t *handles, unsigned int nr_handles,
>  		      unsigned long *vaddrs);
>  
> -int xenbus_alloc_evtchn(struct xenbus_device *dev, int *port);
> -int xenbus_free_evtchn(struct xenbus_device *dev, int port);
> +int xenbus_alloc_evtchn(struct xenbus_device *dev, unsigned int *port);
> +int xenbus_free_evtchn(struct xenbus_device *dev, unsigned int port);

These.


-boris
Yan Yankovskyi March 8, 2020, 1:19 p.m. UTC | #2 
On Sat, Mar 07, 2020 at 02:41:44PM -0500, Boris Ostrovsky wrote:
> 
> 
> On 3/7/20 8:43 AM, Yan Yankovskyi wrote:
> > Make event channel functions pass event channel port using
> > evtchn_port_t type. It eliminates signed <-> unsigned conversion.
> >
> 
> 
> >  static int find_virq(unsigned int virq, unsigned int cpu)
> >  {
> >  	struct evtchn_status status;
> > -	int port, rc = -ENOENT;
> > +	evtchn_port_t port;
> > +	int rc = -ENOENT;
> >  
> >  	memset(&status, 0, sizeof(status));
> >  	for (port = 0; port < xen_evtchn_max_channels(); port++) {
> > @@ -962,7 +963,8 @@ EXPORT_SYMBOL_GPL(xen_evtchn_nr_channels);
> >  int bind_virq_to_irq(unsigned int virq, unsigned int cpu, bool percpu)
> >  {
> >  	struct evtchn_bind_virq bind_virq;
> > -	int evtchn, irq, ret;
> > +	evtchn_port_t evtchn = xen_evtchn_max_channels();
> > +	int irq, ret;
> >  
> >  	mutex_lock(&irq_mapping_update_lock);
> >  
> > @@ -990,7 +992,6 @@ int bind_virq_to_irq(unsigned int virq, unsigned int cpu, bool percpu)
> >  			if (ret == -EEXIST)
> >  				ret = find_virq(virq, cpu);
> >  			BUG_ON(ret < 0);
> > -			evtchn = ret;
> 
> 
> This looks suspicious. What would you be passing to
> xen_irq_info_virq_setup() below?

Right, this line should be preserved.

> I also think that, given that this patch is trying to get types in
> order, find_virq() will need more changes: it is supposed to return
> evtchn_port_t. But then it also wants to return a (signed) error.
 
As we don't care which error we got during find_virq call, we can just
return 0 in case of error, and port number otherwise. Port 0 is never
valid, so this approach can work for the other functions as well.
On the other hand, passing port using pointer and returning actual
error message, as it's done in xenbus_alloc_evtchn(), sounds like a
better approach overall. What do you think?

> >  		}
> >  
> >  		ret = xen_irq_info_virq_setup(cpu, irq, evtchn, virq);
> > @@ -1019,7 +1020,7 @@ static void unbind_from_irq(unsigned int irq)
> >  	mutex_unlock(&irq_mapping_update_lock);
> >  }
> >  
> 
> 
> 
> >  {
> >  	struct evtchn_close close;
> >  	int err;
> > @@ -423,7 +423,7 @@ int xenbus_free_evtchn(struct xenbus_device *dev, int port)
> 
> And why not here, especially since you updated format?

I missed it.

> >  
> >  	err = HYPERVISOR_event_channel_op(EVTCHNOP_close, &close);
> >  	if (err)
> > -		xenbus_dev_error(dev, err, "freeing event channel %d", port);
> > +		xenbus_dev_error(dev, err, "freeing event channel %u", port);
> >  
> >  	return err;
> >  }
> 
> 
> 
> >  
> > diff --git a/include/xen/interface/event_channel.h b/include/xen/interface/event_channel.h
> > index 45650c9a06d5..cf80e338fbb0 100644
> > --- a/include/xen/interface/event_channel.h
> > +++ b/include/xen/interface/event_channel.h
> > @@ -220,7 +220,7 @@ struct evtchn_expand_array {
> >  #define EVTCHNOP_set_priority    13
> >  struct evtchn_set_priority {
> >  	/* IN parameters. */
> > -	uint32_t port;
> > +	evtchn_port_t port;
> 
> This definition comes from Xen so I think it needs to be fixed there first.

Will be done.

> > --- a/drivers/xen/xenbus/xenbus_client.c
> > +++ b/drivers/xen/xenbus/xenbus_client.c
> > @@ -391,7 +391,7 @@ EXPORT_SYMBOL_GPL(xenbus_grant_ring);
> >   * error, the device will switch to XenbusStateClosing, and the error will be
> >   * saved in the store.
> >   */
> > -int xenbus_alloc_evtchn(struct xenbus_device *dev, int *port)
> > +int xenbus_alloc_evtchn(struct xenbus_device *dev, evtchn_port_t *port)
> 
> Right. But then why is the declaration in include/xen/xenbus.h (at the
> very end of the patch) different?
> 
> >  {
> >  	struct evtchn_alloc_unbound alloc_unbound;
> >  	int err;
> > @@ -414,7 +414,7 @@ EXPORT_SYMBOL_GPL(xenbus_alloc_evtchn);
> >  /**
> >   * Free an existing event channel. Returns 0 on success or -errno on error.
> >   */
> > -int xenbus_free_evtchn(struct xenbus_device *dev, int port)
> > +int xenbus_free_evtchn(struct xenbus_device *dev, evtchn_port_t port)
> 
> Here too.
> 
> >  	uint32_t priority;
> >  };
> >  
> > diff --git a/include/xen/xenbus.h b/include/xen/xenbus.h
> > index 89a889585ba0..4f35216064ba 100644
> > --- a/include/xen/xenbus.h
> > +++ b/include/xen/xenbus.h
> > @@ -218,8 +218,8 @@ int xenbus_unmap_ring(struct xenbus_device *dev,
> >  		      grant_handle_t *handles, unsigned int nr_handles,
> >  		      unsigned long *vaddrs);
> >  
> > -int xenbus_alloc_evtchn(struct xenbus_device *dev, int *port);
> > -int xenbus_free_evtchn(struct xenbus_device *dev, int port);
> > +int xenbus_alloc_evtchn(struct xenbus_device *dev, unsigned int *port);
> > +int xenbus_free_evtchn(struct xenbus_device *dev, unsigned int port);
> 
> These.

I was reluctant with inclusion of event channel header into xenbus.
Will be fixed.

> -boris
>
Boris Ostrovsky March 9, 2020, 10:31 p.m. UTC | #3 
On 3/8/20 9:19 AM, Yan Yankovskyi wrote:
> On Sat, Mar 07, 2020 at 02:41:44PM -0500, Boris Ostrovsky wrote:
>
>> I also think that, given that this patch is trying to get types in
>> order, find_virq() will need more changes: it is supposed to return
>> evtchn_port_t. But then it also wants to return a (signed) error.
>  
> As we don't care which error we got during find_virq call, we can just
> return 0 in case of error, and port number otherwise. Port 0 is never
> valid, so this approach can work for the other functions as well.
> On the other hand, passing port using pointer and returning actual
> error message, as it's done in xenbus_alloc_evtchn(), sounds like a
> better approach overall. What do you think?

Either way should be fine.

(BTW, you also need to update evtchn_from_irq(), I think you missed it).

-boris
Jürgen Groß March 10, 2020, 6:21 a.m. UTC | #4 
On 08.03.20 14:19, Yan Yankovskyi wrote:
> On Sat, Mar 07, 2020 at 02:41:44PM -0500, Boris Ostrovsky wrote:
>>
>>
>> On 3/7/20 8:43 AM, Yan Yankovskyi wrote:
>>> Make event channel functions pass event channel port using
>>> evtchn_port_t type. It eliminates signed <-> unsigned conversion.
>>>
>>
>>
>>>   static int find_virq(unsigned int virq, unsigned int cpu)
>>>   {
>>>   	struct evtchn_status status;
>>> -	int port, rc = -ENOENT;
>>> +	evtchn_port_t port;
>>> +	int rc = -ENOENT;
>>>   
>>>   	memset(&status, 0, sizeof(status));
>>>   	for (port = 0; port < xen_evtchn_max_channels(); port++) {
>>> @@ -962,7 +963,8 @@ EXPORT_SYMBOL_GPL(xen_evtchn_nr_channels);
>>>   int bind_virq_to_irq(unsigned int virq, unsigned int cpu, bool percpu)
>>>   {
>>>   	struct evtchn_bind_virq bind_virq;
>>> -	int evtchn, irq, ret;
>>> +	evtchn_port_t evtchn = xen_evtchn_max_channels();
>>> +	int irq, ret;
>>>   
>>>   	mutex_lock(&irq_mapping_update_lock);
>>>   
>>> @@ -990,7 +992,6 @@ int bind_virq_to_irq(unsigned int virq, unsigned int cpu, bool percpu)
>>>   			if (ret == -EEXIST)
>>>   				ret = find_virq(virq, cpu);
>>>   			BUG_ON(ret < 0);
>>> -			evtchn = ret;
>>
>>
>> This looks suspicious. What would you be passing to
>> xen_irq_info_virq_setup() below?
> 
> Right, this line should be preserved.
> 
>> I also think that, given that this patch is trying to get types in
>> order, find_virq() will need more changes: it is supposed to return
>> evtchn_port_t. But then it also wants to return a (signed) error.
>   
> As we don't care which error we got during find_virq call, we can just
> return 0 in case of error, and port number otherwise. Port 0 is never
> valid, so this approach can work for the other functions as well.
> On the other hand, passing port using pointer and returning actual
> error message, as it's done in xenbus_alloc_evtchn(), sounds like a
> better approach overall. What do you think?

You can use the same approach as Xen tools do and define something like:

typedef int evtchn_port_or_error_t;


Juergen
diff mbox series

Patch

diff --git a/drivers/xen/events/events_2l.c b/drivers/xen/events/events_2l.c
index 8edef51c92e5..64df919a2111 100644
--- a/drivers/xen/events/events_2l.c
+++ b/drivers/xen/events/events_2l.c
@@ -53,37 +53,37 @@  static void evtchn_2l_bind_to_cpu(struct irq_info *info, unsigned cpu)
 	set_bit(info->evtchn, BM(per_cpu(cpu_evtchn_mask, cpu)));
 }
 
-static void evtchn_2l_clear_pending(unsigned port)
+static void evtchn_2l_clear_pending(evtchn_port_t port)
 {
 	struct shared_info *s = HYPERVISOR_shared_info;
 	sync_clear_bit(port, BM(&s->evtchn_pending[0]));
 }
 
-static void evtchn_2l_set_pending(unsigned port)
+static void evtchn_2l_set_pending(evtchn_port_t port)
 {
 	struct shared_info *s = HYPERVISOR_shared_info;
 	sync_set_bit(port, BM(&s->evtchn_pending[0]));
 }
 
-static bool evtchn_2l_is_pending(unsigned port)
+static bool evtchn_2l_is_pending(evtchn_port_t port)
 {
 	struct shared_info *s = HYPERVISOR_shared_info;
 	return sync_test_bit(port, BM(&s->evtchn_pending[0]));
 }
 
-static bool evtchn_2l_test_and_set_mask(unsigned port)
+static bool evtchn_2l_test_and_set_mask(evtchn_port_t port)
 {
 	struct shared_info *s = HYPERVISOR_shared_info;
 	return sync_test_and_set_bit(port, BM(&s->evtchn_mask[0]));
 }
 
-static void evtchn_2l_mask(unsigned port)
+static void evtchn_2l_mask(evtchn_port_t port)
 {
 	struct shared_info *s = HYPERVISOR_shared_info;
 	sync_set_bit(port, BM(&s->evtchn_mask[0]));
 }
 
-static void evtchn_2l_unmask(unsigned port)
+static void evtchn_2l_unmask(evtchn_port_t port)
 {
 	struct shared_info *s = HYPERVISOR_shared_info;
 	unsigned int cpu = get_cpu();
@@ -173,7 +173,7 @@  static void evtchn_2l_handle_events(unsigned cpu)
 	/* Timer interrupt has highest priority. */
 	irq = irq_from_virq(cpu, VIRQ_TIMER);
 	if (irq != -1) {
-		unsigned int evtchn = evtchn_from_irq(irq);
+		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))
@@ -228,7 +228,7 @@  static void evtchn_2l_handle_events(unsigned cpu)
 
 		do {
 			xen_ulong_t bits;
-			int port;
+			evtchn_port_t port;
 
 			bits = MASK_LSBS(pending_bits, bit_idx);
 
diff --git a/drivers/xen/events/events_base.c b/drivers/xen/events/events_base.c
index 499eff7d3f65..06f6cb01af39 100644
--- a/drivers/xen/events/events_base.c
+++ b/drivers/xen/events/events_base.c
@@ -116,7 +116,7 @@  static void clear_evtchn_to_irq_all(void)
 	}
 }
 
-static int set_evtchn_to_irq(unsigned evtchn, unsigned irq)
+static int set_evtchn_to_irq(evtchn_port_t evtchn, unsigned int irq)
 {
 	unsigned row;
 	unsigned col;
@@ -143,7 +143,7 @@  static int set_evtchn_to_irq(unsigned evtchn, unsigned irq)
 	return 0;
 }
 
-int get_evtchn_to_irq(unsigned evtchn)
+int get_evtchn_to_irq(evtchn_port_t evtchn)
 {
 	if (evtchn >= xen_evtchn_max_channels())
 		return -1;
@@ -162,7 +162,7 @@  struct irq_info *info_for_irq(unsigned irq)
 static int xen_irq_info_common_setup(struct irq_info *info,
 				     unsigned irq,
 				     enum xen_irq_type type,
-				     unsigned evtchn,
+				     evtchn_port_t evtchn,
 				     unsigned short cpu)
 {
 	int ret;
@@ -184,7 +184,7 @@  static int xen_irq_info_common_setup(struct irq_info *info,
 }
 
 static int xen_irq_info_evtchn_setup(unsigned irq,
-				     unsigned evtchn)
+				     evtchn_port_t evtchn)
 {
 	struct irq_info *info = info_for_irq(irq);
 
@@ -193,7 +193,7 @@  static int xen_irq_info_evtchn_setup(unsigned irq,
 
 static int xen_irq_info_ipi_setup(unsigned cpu,
 				  unsigned irq,
-				  unsigned evtchn,
+				  evtchn_port_t evtchn,
 				  enum ipi_vector ipi)
 {
 	struct irq_info *info = info_for_irq(irq);
@@ -207,7 +207,7 @@  static int xen_irq_info_ipi_setup(unsigned cpu,
 
 static int xen_irq_info_virq_setup(unsigned cpu,
 				   unsigned irq,
-				   unsigned evtchn,
+				   evtchn_port_t evtchn,
 				   unsigned virq)
 {
 	struct irq_info *info = info_for_irq(irq);
@@ -220,7 +220,7 @@  static int xen_irq_info_virq_setup(unsigned cpu,
 }
 
 static int xen_irq_info_pirq_setup(unsigned irq,
-				   unsigned evtchn,
+				   evtchn_port_t evtchn,
 				   unsigned pirq,
 				   unsigned gsi,
 				   uint16_t domid,
@@ -253,7 +253,7 @@  unsigned int evtchn_from_irq(unsigned irq)
 	return info_for_irq(irq)->evtchn;
 }
 
-unsigned irq_from_evtchn(unsigned int evtchn)
+unsigned int irq_from_evtchn(evtchn_port_t evtchn)
 {
 	return get_evtchn_to_irq(evtchn);
 }
@@ -304,7 +304,7 @@  unsigned cpu_from_irq(unsigned irq)
 	return info_for_irq(irq)->cpu;
 }
 
-unsigned int cpu_from_evtchn(unsigned int evtchn)
+unsigned int cpu_from_evtchn(evtchn_port_t evtchn)
 {
 	int irq = get_evtchn_to_irq(evtchn);
 	unsigned ret = 0;
@@ -354,7 +354,7 @@  static void bind_evtchn_to_cpu(unsigned int chn, unsigned int cpu)
  */
 void notify_remote_via_irq(int irq)
 {
-	int evtchn = evtchn_from_irq(irq);
+	evtchn_port_t evtchn = evtchn_from_irq(irq);
 
 	if (VALID_EVTCHN(evtchn))
 		notify_remote_via_evtchn(evtchn);
@@ -445,7 +445,7 @@  static void xen_free_irq(unsigned irq)
 	irq_free_desc(irq);
 }
 
-static void xen_evtchn_close(unsigned int port)
+static void xen_evtchn_close(evtchn_port_t port)
 {
 	struct evtchn_close close;
 
@@ -472,7 +472,7 @@  static void pirq_query_unmask(int irq)
 
 static void eoi_pirq(struct irq_data *data)
 {
-	int evtchn = evtchn_from_irq(data->irq);
+	evtchn_port_t evtchn = evtchn_from_irq(data->irq);
 	struct physdev_eoi eoi = { .irq = pirq_from_irq(data->irq) };
 	int rc = 0;
 
@@ -508,7 +508,7 @@  static unsigned int __startup_pirq(unsigned int irq)
 {
 	struct evtchn_bind_pirq bind_pirq;
 	struct irq_info *info = info_for_irq(irq);
-	int evtchn = evtchn_from_irq(irq);
+	evtchn_port_t evtchn = evtchn_from_irq(irq);
 	int rc;
 
 	BUG_ON(info->type != IRQT_PIRQ);
@@ -561,7 +561,7 @@  static void shutdown_pirq(struct irq_data *data)
 {
 	unsigned int irq = data->irq;
 	struct irq_info *info = info_for_irq(irq);
-	unsigned evtchn = evtchn_from_irq(irq);
+	evtchn_port_t evtchn = evtchn_from_irq(irq);
 
 	BUG_ON(info->type != IRQT_PIRQ);
 
@@ -601,7 +601,7 @@  EXPORT_SYMBOL_GPL(xen_irq_from_gsi);
 
 static void __unbind_from_irq(unsigned int irq)
 {
-	int evtchn = evtchn_from_irq(irq);
+	evtchn_port_t evtchn = evtchn_from_irq(irq);
 	struct irq_info *info = irq_get_handler_data(irq);
 
 	if (info->refcnt > 0) {
@@ -827,7 +827,7 @@  int xen_pirq_from_irq(unsigned irq)
 }
 EXPORT_SYMBOL_GPL(xen_pirq_from_irq);
 
-int bind_evtchn_to_irq(unsigned int evtchn)
+int bind_evtchn_to_irq(evtchn_port_t evtchn)
 {
 	int irq;
 	int ret;
@@ -870,8 +870,8 @@  EXPORT_SYMBOL_GPL(bind_evtchn_to_irq);
 static int bind_ipi_to_irq(unsigned int ipi, unsigned int cpu)
 {
 	struct evtchn_bind_ipi bind_ipi;
-	int evtchn, irq;
-	int ret;
+	evtchn_port_t evtchn;
+	int ret, irq;
 
 	mutex_lock(&irq_mapping_update_lock);
 
@@ -909,7 +909,7 @@  static int bind_ipi_to_irq(unsigned int ipi, unsigned int cpu)
 }
 
 int bind_interdomain_evtchn_to_irq(unsigned int remote_domain,
-				   unsigned int remote_port)
+				   evtchn_port_t remote_port)
 {
 	struct evtchn_bind_interdomain bind_interdomain;
 	int err;
@@ -927,7 +927,8 @@  EXPORT_SYMBOL_GPL(bind_interdomain_evtchn_to_irq);
 static int find_virq(unsigned int virq, unsigned int cpu)
 {
 	struct evtchn_status status;
-	int port, rc = -ENOENT;
+	evtchn_port_t port;
+	int rc = -ENOENT;
 
 	memset(&status, 0, sizeof(status));
 	for (port = 0; port < xen_evtchn_max_channels(); port++) {
@@ -962,7 +963,8 @@  EXPORT_SYMBOL_GPL(xen_evtchn_nr_channels);
 int bind_virq_to_irq(unsigned int virq, unsigned int cpu, bool percpu)
 {
 	struct evtchn_bind_virq bind_virq;
-	int evtchn, irq, ret;
+	evtchn_port_t evtchn = xen_evtchn_max_channels();
+	int irq, ret;
 
 	mutex_lock(&irq_mapping_update_lock);
 
@@ -990,7 +992,6 @@  int bind_virq_to_irq(unsigned int virq, unsigned int cpu, bool percpu)
 			if (ret == -EEXIST)
 				ret = find_virq(virq, cpu);
 			BUG_ON(ret < 0);
-			evtchn = ret;
 		}
 
 		ret = xen_irq_info_virq_setup(cpu, irq, evtchn, virq);
@@ -1019,7 +1020,7 @@  static void unbind_from_irq(unsigned int irq)
 	mutex_unlock(&irq_mapping_update_lock);
 }
 
-int bind_evtchn_to_irqhandler(unsigned int evtchn,
+int bind_evtchn_to_irqhandler(evtchn_port_t evtchn,
 			      irq_handler_t handler,
 			      unsigned long irqflags,
 			      const char *devname, void *dev_id)
@@ -1040,7 +1041,7 @@  int bind_evtchn_to_irqhandler(unsigned int evtchn,
 EXPORT_SYMBOL_GPL(bind_evtchn_to_irqhandler);
 
 int bind_interdomain_evtchn_to_irqhandler(unsigned int remote_domain,
-					  unsigned int remote_port,
+					  evtchn_port_t remote_port,
 					  irq_handler_t handler,
 					  unsigned long irqflags,
 					  const char *devname,
@@ -1132,7 +1133,7 @@  int xen_set_irq_priority(unsigned irq, unsigned priority)
 }
 EXPORT_SYMBOL_GPL(xen_set_irq_priority);
 
-int evtchn_make_refcounted(unsigned int evtchn)
+int evtchn_make_refcounted(evtchn_port_t evtchn)
 {
 	int irq = get_evtchn_to_irq(evtchn);
 	struct irq_info *info;
@@ -1153,7 +1154,7 @@  int evtchn_make_refcounted(unsigned int evtchn)
 }
 EXPORT_SYMBOL_GPL(evtchn_make_refcounted);
 
-int evtchn_get(unsigned int evtchn)
+int evtchn_get(evtchn_port_t evtchn)
 {
 	int irq;
 	struct irq_info *info;
@@ -1186,7 +1187,7 @@  int evtchn_get(unsigned int evtchn)
 }
 EXPORT_SYMBOL_GPL(evtchn_get);
 
-void evtchn_put(unsigned int evtchn)
+void evtchn_put(evtchn_port_t evtchn)
 {
 	int irq = get_evtchn_to_irq(evtchn);
 	if (WARN_ON(irq == -1))
@@ -1252,7 +1253,7 @@  void xen_hvm_evtchn_do_upcall(void)
 EXPORT_SYMBOL_GPL(xen_hvm_evtchn_do_upcall);
 
 /* Rebind a new event channel to an existing irq. */
-void rebind_evtchn_irq(int evtchn, int irq)
+void rebind_evtchn_irq(evtchn_port_t evtchn, int irq)
 {
 	struct irq_info *info = info_for_irq(irq);
 
@@ -1275,7 +1276,7 @@  void rebind_evtchn_irq(int evtchn, int irq)
 
 	mutex_unlock(&irq_mapping_update_lock);
 
-        bind_evtchn_to_cpu(evtchn, info->cpu);
+	bind_evtchn_to_cpu(evtchn, info->cpu);
 	/* This will be deferred until interrupt is processed */
 	irq_set_affinity(irq, cpumask_of(info->cpu));
 
@@ -1284,7 +1285,7 @@  void rebind_evtchn_irq(int evtchn, int irq)
 }
 
 /* Rebind an evtchn so that it gets delivered to a specific cpu */
-static int xen_rebind_evtchn_to_cpu(int evtchn, unsigned int tcpu)
+static int xen_rebind_evtchn_to_cpu(evtchn_port_t evtchn, unsigned int tcpu)
 {
 	struct evtchn_bind_vcpu bind_vcpu;
 	int masked;
@@ -1342,7 +1343,7 @@  EXPORT_SYMBOL_GPL(xen_set_affinity_evtchn);
 
 static void enable_dynirq(struct irq_data *data)
 {
-	int evtchn = evtchn_from_irq(data->irq);
+	evtchn_port_t evtchn = evtchn_from_irq(data->irq);
 
 	if (VALID_EVTCHN(evtchn))
 		unmask_evtchn(evtchn);
@@ -1350,7 +1351,7 @@  static void enable_dynirq(struct irq_data *data)
 
 static void disable_dynirq(struct irq_data *data)
 {
-	int evtchn = evtchn_from_irq(data->irq);
+	evtchn_port_t evtchn = evtchn_from_irq(data->irq);
 
 	if (VALID_EVTCHN(evtchn))
 		mask_evtchn(evtchn);
@@ -1358,7 +1359,7 @@  static void disable_dynirq(struct irq_data *data)
 
 static void ack_dynirq(struct irq_data *data)
 {
-	int evtchn = evtchn_from_irq(data->irq);
+	evtchn_port_t evtchn = evtchn_from_irq(data->irq);
 
 	if (!VALID_EVTCHN(evtchn))
 		return;
@@ -1385,7 +1386,7 @@  static void mask_ack_dynirq(struct irq_data *data)
 
 static int retrigger_dynirq(struct irq_data *data)
 {
-	unsigned int evtchn = evtchn_from_irq(data->irq);
+	evtchn_port_t evtchn = evtchn_from_irq(data->irq);
 	int masked;
 
 	if (!VALID_EVTCHN(evtchn))
@@ -1440,7 +1441,8 @@  static void restore_pirqs(void)
 static void restore_cpu_virqs(unsigned int cpu)
 {
 	struct evtchn_bind_virq bind_virq;
-	int virq, irq, evtchn;
+	evtchn_port_t evtchn;
+	int virq, irq;
 
 	for (virq = 0; virq < NR_VIRQS; virq++) {
 		if ((irq = per_cpu(virq_to_irq, cpu)[virq]) == -1)
@@ -1465,7 +1467,8 @@  static void restore_cpu_virqs(unsigned int cpu)
 static void restore_cpu_ipis(unsigned int cpu)
 {
 	struct evtchn_bind_ipi bind_ipi;
-	int ipi, irq, evtchn;
+	evtchn_port_t evtchn;
+	int ipi, irq;
 
 	for (ipi = 0; ipi < XEN_NR_IPIS; ipi++) {
 		if ((irq = per_cpu(ipi_to_irq, cpu)[ipi]) == -1)
@@ -1489,7 +1492,7 @@  static void restore_cpu_ipis(unsigned int cpu)
 /* Clear an irq's pending state, in preparation for polling on it */
 void xen_clear_irq_pending(int irq)
 {
-	int evtchn = evtchn_from_irq(irq);
+	evtchn_port_t evtchn = evtchn_from_irq(irq);
 
 	if (VALID_EVTCHN(evtchn))
 		clear_evtchn(evtchn);
@@ -1497,7 +1500,7 @@  void xen_clear_irq_pending(int irq)
 EXPORT_SYMBOL(xen_clear_irq_pending);
 void xen_set_irq_pending(int irq)
 {
-	int evtchn = evtchn_from_irq(irq);
+	evtchn_port_t evtchn = evtchn_from_irq(irq);
 
 	if (VALID_EVTCHN(evtchn))
 		set_evtchn(evtchn);
@@ -1505,7 +1508,7 @@  void xen_set_irq_pending(int irq)
 
 bool xen_test_irq_pending(int irq)
 {
-	int evtchn = evtchn_from_irq(irq);
+	evtchn_port_t evtchn = evtchn_from_irq(irq);
 	bool ret = false;
 
 	if (VALID_EVTCHN(evtchn))
@@ -1667,7 +1670,7 @@  module_param(fifo_events, bool, 0);
 void __init xen_init_IRQ(void)
 {
 	int ret = -EINVAL;
-	unsigned int evtchn;
+	evtchn_port_t evtchn;
 
 	if (fifo_events)
 		ret = xen_evtchn_fifo_init();
diff --git a/drivers/xen/events/events_fifo.c b/drivers/xen/events/events_fifo.c
index 76b318e88382..c60ee0450173 100644
--- a/drivers/xen/events/events_fifo.c
+++ b/drivers/xen/events/events_fifo.c
@@ -82,7 +82,7 @@  static unsigned event_array_pages __read_mostly;
 
 #endif
 
-static inline event_word_t *event_word_from_port(unsigned port)
+static inline event_word_t *event_word_from_port(evtchn_port_t port)
 {
 	unsigned i = port / EVENT_WORDS_PER_PAGE;
 
@@ -140,7 +140,7 @@  static void init_array_page(event_word_t *array_page)
 
 static int evtchn_fifo_setup(struct irq_info *info)
 {
-	unsigned port = info->evtchn;
+	evtchn_port_t port = info->evtchn;
 	unsigned new_array_pages;
 	int ret;
 
@@ -191,37 +191,37 @@  static void evtchn_fifo_bind_to_cpu(struct irq_info *info, unsigned cpu)
 	/* no-op */
 }
 
-static void evtchn_fifo_clear_pending(unsigned port)
+static void evtchn_fifo_clear_pending(evtchn_port_t port)
 {
 	event_word_t *word = event_word_from_port(port);
 	sync_clear_bit(EVTCHN_FIFO_BIT(PENDING, word), BM(word));
 }
 
-static void evtchn_fifo_set_pending(unsigned port)
+static void evtchn_fifo_set_pending(evtchn_port_t port)
 {
 	event_word_t *word = event_word_from_port(port);
 	sync_set_bit(EVTCHN_FIFO_BIT(PENDING, word), BM(word));
 }
 
-static bool evtchn_fifo_is_pending(unsigned port)
+static bool evtchn_fifo_is_pending(evtchn_port_t port)
 {
 	event_word_t *word = event_word_from_port(port);
 	return sync_test_bit(EVTCHN_FIFO_BIT(PENDING, word), BM(word));
 }
 
-static bool evtchn_fifo_test_and_set_mask(unsigned port)
+static bool evtchn_fifo_test_and_set_mask(evtchn_port_t port)
 {
 	event_word_t *word = event_word_from_port(port);
 	return sync_test_and_set_bit(EVTCHN_FIFO_BIT(MASKED, word), BM(word));
 }
 
-static void evtchn_fifo_mask(unsigned port)
+static void evtchn_fifo_mask(evtchn_port_t port)
 {
 	event_word_t *word = event_word_from_port(port);
 	sync_set_bit(EVTCHN_FIFO_BIT(MASKED, word), BM(word));
 }
 
-static bool evtchn_fifo_is_masked(unsigned port)
+static bool evtchn_fifo_is_masked(evtchn_port_t port)
 {
 	event_word_t *word = event_word_from_port(port);
 	return sync_test_bit(EVTCHN_FIFO_BIT(MASKED, word), BM(word));
@@ -242,7 +242,7 @@  static void clear_masked(volatile event_word_t *word)
 	} while (w != old);
 }
 
-static void evtchn_fifo_unmask(unsigned port)
+static void evtchn_fifo_unmask(evtchn_port_t port)
 {
 	event_word_t *word = event_word_from_port(port);
 
@@ -270,7 +270,7 @@  static uint32_t clear_linked(volatile event_word_t *word)
 	return w & EVTCHN_FIFO_LINK_MASK;
 }
 
-static void handle_irq_for_port(unsigned port)
+static void handle_irq_for_port(evtchn_port_t port)
 {
 	int irq;
 
@@ -286,7 +286,7 @@  static void consume_one_event(unsigned cpu,
 {
 	struct evtchn_fifo_queue *q = &per_cpu(cpu_queue, cpu);
 	uint32_t head;
-	unsigned port;
+	evtchn_port_t port;
 	event_word_t *word;
 
 	head = q->head[priority];
diff --git a/drivers/xen/events/events_internal.h b/drivers/xen/events/events_internal.h
index 82938cff6c7a..10684feb094e 100644
--- a/drivers/xen/events/events_internal.h
+++ b/drivers/xen/events/events_internal.h
@@ -33,7 +33,7 @@  struct irq_info {
 	int refcnt;
 	enum xen_irq_type type;	/* type */
 	unsigned irq;
-	unsigned int evtchn;	/* event channel */
+	evtchn_port_t evtchn;	/* event channel */
 	unsigned short cpu;	/* cpu bound */
 
 	union {
@@ -60,12 +60,12 @@  struct evtchn_ops {
 	int (*setup)(struct irq_info *info);
 	void (*bind_to_cpu)(struct irq_info *info, unsigned cpu);
 
-	void (*clear_pending)(unsigned port);
-	void (*set_pending)(unsigned port);
-	bool (*is_pending)(unsigned port);
-	bool (*test_and_set_mask)(unsigned port);
-	void (*mask)(unsigned port);
-	void (*unmask)(unsigned port);
+	void (*clear_pending)(evtchn_port_t port);
+	void (*set_pending)(evtchn_port_t port);
+	bool (*is_pending)(evtchn_port_t port);
+	bool (*test_and_set_mask)(evtchn_port_t port);
+	void (*mask)(evtchn_port_t port);
+	void (*unmask)(evtchn_port_t port);
 
 	void (*handle_events)(unsigned cpu);
 	void (*resume)(void);
@@ -74,11 +74,11 @@  struct evtchn_ops {
 extern const struct evtchn_ops *evtchn_ops;
 
 extern int **evtchn_to_irq;
-int get_evtchn_to_irq(unsigned int evtchn);
+int get_evtchn_to_irq(evtchn_port_t evtchn);
 
 struct irq_info *info_for_irq(unsigned irq);
 unsigned cpu_from_irq(unsigned irq);
-unsigned cpu_from_evtchn(unsigned int evtchn);
+unsigned int cpu_from_evtchn(evtchn_port_t evtchn);
 
 static inline unsigned xen_evtchn_max_channels(void)
 {
@@ -102,32 +102,32 @@  static inline void xen_evtchn_port_bind_to_cpu(struct irq_info *info,
 	evtchn_ops->bind_to_cpu(info, cpu);
 }
 
-static inline void clear_evtchn(unsigned port)
+static inline void clear_evtchn(evtchn_port_t port)
 {
 	evtchn_ops->clear_pending(port);
 }
 
-static inline void set_evtchn(unsigned port)
+static inline void set_evtchn(evtchn_port_t port)
 {
 	evtchn_ops->set_pending(port);
 }
 
-static inline bool test_evtchn(unsigned port)
+static inline bool test_evtchn(evtchn_port_t port)
 {
 	return evtchn_ops->is_pending(port);
 }
 
-static inline bool test_and_set_mask(unsigned port)
+static inline bool test_and_set_mask(evtchn_port_t port)
 {
 	return evtchn_ops->test_and_set_mask(port);
 }
 
-static inline void mask_evtchn(unsigned port)
+static inline void mask_evtchn(evtchn_port_t port)
 {
 	return evtchn_ops->mask(port);
 }
 
-static inline void unmask_evtchn(unsigned port)
+static inline void unmask_evtchn(evtchn_port_t port)
 {
 	return evtchn_ops->unmask(port);
 }
diff --git a/drivers/xen/evtchn.c b/drivers/xen/evtchn.c
index 052b55a14ebc..6e0b1dd5573c 100644
--- a/drivers/xen/evtchn.c
+++ b/drivers/xen/evtchn.c
@@ -83,7 +83,7 @@  struct per_user_data {
 struct user_evtchn {
 	struct rb_node node;
 	struct per_user_data *user;
-	unsigned port;
+	evtchn_port_t port;
 	bool enabled;
 };
 
@@ -138,7 +138,8 @@  static void del_evtchn(struct per_user_data *u, struct user_evtchn *evtchn)
 	kfree(evtchn);
 }
 
-static struct user_evtchn *find_evtchn(struct per_user_data *u, unsigned port)
+static struct user_evtchn *find_evtchn(struct per_user_data *u,
+				       evtchn_port_t port)
 {
 	struct rb_node *node = u->evtchns.rb_node;
 
@@ -163,7 +164,7 @@  static irqreturn_t evtchn_interrupt(int irq, void *data)
 	struct per_user_data *u = evtchn->user;
 
 	WARN(!evtchn->enabled,
-	     "Interrupt for port %d, but apparently not enabled; per-user %p\n",
+	     "Interrupt for port %u, but apparently not enabled; per-user %p\n",
 	     evtchn->port, u);
 
 	disable_irq_nosync(irq);
@@ -286,7 +287,7 @@  static ssize_t evtchn_write(struct file *file, const char __user *buf,
 	mutex_lock(&u->bind_mutex);
 
 	for (i = 0; i < (count/sizeof(evtchn_port_t)); i++) {
-		unsigned port = kbuf[i];
+		evtchn_port_t port = kbuf[i];
 		struct user_evtchn *evtchn;
 
 		evtchn = find_evtchn(u, port);
@@ -361,7 +362,7 @@  static int evtchn_resize_ring(struct per_user_data *u)
 	return 0;
 }
 
-static int evtchn_bind_to_user(struct per_user_data *u, int port)
+static int evtchn_bind_to_user(struct per_user_data *u, evtchn_port_t port)
 {
 	struct user_evtchn *evtchn;
 	struct evtchn_close close;
@@ -423,7 +424,7 @@  static void evtchn_unbind_from_user(struct per_user_data *u,
 
 static DEFINE_PER_CPU(int, bind_last_selected_cpu);
 
-static void evtchn_bind_interdom_next_vcpu(int evtchn)
+static void evtchn_bind_interdom_next_vcpu(evtchn_port_t evtchn)
 {
 	unsigned int selected_cpu, irq;
 	struct irq_desc *desc;
diff --git a/drivers/xen/pvcalls-back.c b/drivers/xen/pvcalls-back.c
index c57c71b7d53d..cf4ce3e9358d 100644
--- a/drivers/xen/pvcalls-back.c
+++ b/drivers/xen/pvcalls-back.c
@@ -300,7 +300,7 @@  static struct sock_mapping *pvcalls_new_active_socket(
 		struct pvcalls_fedata *fedata,
 		uint64_t id,
 		grant_ref_t ref,
-		uint32_t evtchn,
+		evtchn_port_t evtchn,
 		struct socket *sock)
 {
 	int ret;
@@ -905,7 +905,8 @@  static irqreturn_t pvcalls_back_conn_event(int irq, void *sock_map)
 
 static int backend_connect(struct xenbus_device *dev)
 {
-	int err, evtchn;
+	int err;
+	evtchn_port_t evtchn;
 	grant_ref_t ring_ref;
 	struct pvcalls_fedata *fedata = NULL;
 
diff --git a/drivers/xen/xen-pciback/xenbus.c b/drivers/xen/xen-pciback/xenbus.c
index 833b2d2c4318..f2115587855f 100644
--- a/drivers/xen/xen-pciback/xenbus.c
+++ b/drivers/xen/xen-pciback/xenbus.c
@@ -105,13 +105,13 @@  static void free_pdev(struct xen_pcibk_device *pdev)
 }
 
 static int xen_pcibk_do_attach(struct xen_pcibk_device *pdev, int gnt_ref,
-			     int remote_evtchn)
+			     evtchn_port_t remote_evtchn)
 {
 	int err = 0;
 	void *vaddr;
 
 	dev_dbg(&pdev->xdev->dev,
-		"Attaching to frontend resources - gnt_ref=%d evtchn=%d\n",
+		"Attaching to frontend resources - gnt_ref=%d evtchn=%u\n",
 		gnt_ref, remote_evtchn);
 
 	err = xenbus_map_ring_valloc(pdev->xdev, &gnt_ref, 1, &vaddr);
@@ -142,7 +142,8 @@  static int xen_pcibk_do_attach(struct xen_pcibk_device *pdev, int gnt_ref,
 static int xen_pcibk_attach(struct xen_pcibk_device *pdev)
 {
 	int err = 0;
-	int gnt_ref, remote_evtchn;
+	int gnt_ref;
+	evtchn_port_t remote_evtchn;
 	char *magic = NULL;
 
 
diff --git a/drivers/xen/xen-scsiback.c b/drivers/xen/xen-scsiback.c
index ba0942e481bc..75c0a2e9a6db 100644
--- a/drivers/xen/xen-scsiback.c
+++ b/drivers/xen/xen-scsiback.c
@@ -854,7 +854,8 @@  static int scsiback_init_sring(struct vscsibk_info *info, grant_ref_t ring_ref,
 static int scsiback_map(struct vscsibk_info *info)
 {
 	struct xenbus_device *dev = info->dev;
-	unsigned int ring_ref, evtchn;
+	unsigned int ring_ref;
+	evtchn_port_t evtchn;
 	int err;
 
 	err = xenbus_gather(XBT_NIL, dev->otherend,
diff --git a/drivers/xen/xenbus/xenbus_client.c b/drivers/xen/xenbus/xenbus_client.c
index e17ca8156171..1f87514e4efc 100644
--- a/drivers/xen/xenbus/xenbus_client.c
+++ b/drivers/xen/xenbus/xenbus_client.c
@@ -391,7 +391,7 @@  EXPORT_SYMBOL_GPL(xenbus_grant_ring);
  * error, the device will switch to XenbusStateClosing, and the error will be
  * saved in the store.
  */
-int xenbus_alloc_evtchn(struct xenbus_device *dev, int *port)
+int xenbus_alloc_evtchn(struct xenbus_device *dev, evtchn_port_t *port)
 {
 	struct evtchn_alloc_unbound alloc_unbound;
 	int err;
@@ -414,7 +414,7 @@  EXPORT_SYMBOL_GPL(xenbus_alloc_evtchn);
 /**
  * Free an existing event channel. Returns 0 on success or -errno on error.
  */
-int xenbus_free_evtchn(struct xenbus_device *dev, int port)
+int xenbus_free_evtchn(struct xenbus_device *dev, evtchn_port_t port)
 {
 	struct evtchn_close close;
 	int err;
@@ -423,7 +423,7 @@  int xenbus_free_evtchn(struct xenbus_device *dev, int port)
 
 	err = HYPERVISOR_event_channel_op(EVTCHNOP_close, &close);
 	if (err)
-		xenbus_dev_error(dev, err, "freeing event channel %d", port);
+		xenbus_dev_error(dev, err, "freeing event channel %u", port);
 
 	return err;
 }
diff --git a/include/xen/events.h b/include/xen/events.h
index c0e6a0598397..7fe5a73b8bda 100644
--- a/include/xen/events.h
+++ b/include/xen/events.h
@@ -14,8 +14,8 @@ 
 
 unsigned xen_evtchn_nr_channels(void);
 
-int bind_evtchn_to_irq(unsigned int evtchn);
-int bind_evtchn_to_irqhandler(unsigned int evtchn,
+int bind_evtchn_to_irq(evtchn_port_t evtchn);
+int bind_evtchn_to_irqhandler(evtchn_port_t evtchn,
 			      irq_handler_t handler,
 			      unsigned long irqflags, const char *devname,
 			      void *dev_id);
@@ -31,9 +31,9 @@  int bind_ipi_to_irqhandler(enum ipi_vector ipi,
 			   const char *devname,
 			   void *dev_id);
 int bind_interdomain_evtchn_to_irq(unsigned int remote_domain,
-				   unsigned int remote_port);
+				   evtchn_port_t remote_port);
 int bind_interdomain_evtchn_to_irqhandler(unsigned int remote_domain,
-					  unsigned int remote_port,
+					  evtchn_port_t remote_port,
 					  irq_handler_t handler,
 					  unsigned long irqflags,
 					  const char *devname,
@@ -54,15 +54,15 @@  int xen_set_irq_priority(unsigned irq, unsigned priority);
 /*
  * Allow extra references to event channels exposed to userspace by evtchn
  */
-int evtchn_make_refcounted(unsigned int evtchn);
-int evtchn_get(unsigned int evtchn);
-void evtchn_put(unsigned int evtchn);
+int evtchn_make_refcounted(evtchn_port_t evtchn);
+int evtchn_get(evtchn_port_t evtchn);
+void evtchn_put(evtchn_port_t evtchn);
 
 void xen_send_IPI_one(unsigned int cpu, enum ipi_vector vector);
-void rebind_evtchn_irq(int evtchn, int irq);
+void rebind_evtchn_irq(evtchn_port_t evtchn, int irq);
 int xen_set_affinity_evtchn(struct irq_desc *desc, unsigned int tcpu);
 
-static inline void notify_remote_via_evtchn(int port)
+static inline void notify_remote_via_evtchn(evtchn_port_t port)
 {
 	struct evtchn_send send = { .port = port };
 	(void)HYPERVISOR_event_channel_op(EVTCHNOP_send, &send);
@@ -86,7 +86,7 @@  void xen_poll_irq(int irq);
 void xen_poll_irq_timeout(int irq, u64 timeout);
 
 /* Determine the IRQ which is bound to an event channel */
-unsigned irq_from_evtchn(unsigned int evtchn);
+unsigned int irq_from_evtchn(evtchn_port_t evtchn);
 int irq_from_virq(unsigned int cpu, unsigned int virq);
 unsigned int evtchn_from_irq(unsigned irq);
 
diff --git a/include/xen/interface/event_channel.h b/include/xen/interface/event_channel.h
index 45650c9a06d5..cf80e338fbb0 100644
--- a/include/xen/interface/event_channel.h
+++ b/include/xen/interface/event_channel.h
@@ -220,7 +220,7 @@  struct evtchn_expand_array {
 #define EVTCHNOP_set_priority    13
 struct evtchn_set_priority {
 	/* IN parameters. */
-	uint32_t port;
+	evtchn_port_t port;
 	uint32_t priority;
 };
 
diff --git a/include/xen/xenbus.h b/include/xen/xenbus.h
index 89a889585ba0..4f35216064ba 100644
--- a/include/xen/xenbus.h
+++ b/include/xen/xenbus.h
@@ -218,8 +218,8 @@  int xenbus_unmap_ring(struct xenbus_device *dev,
 		      grant_handle_t *handles, unsigned int nr_handles,
 		      unsigned long *vaddrs);
 
-int xenbus_alloc_evtchn(struct xenbus_device *dev, int *port);
-int xenbus_free_evtchn(struct xenbus_device *dev, int port);
+int xenbus_alloc_evtchn(struct xenbus_device *dev, unsigned int *port);
+int xenbus_free_evtchn(struct xenbus_device *dev, unsigned int port);
 
 enum xenbus_state xenbus_read_driver_state(const char *path);