diff mbox

[RFC,v2,3/6] irq: bypass: Extend skeleton for ARM forwarding control

Message ID 1436184692-20927-4-git-send-email-eric.auger@linaro.org (mailing list archive)
State New, archived
Headers show

Commit Message

Eric Auger July 6, 2015, 12:11 p.m. UTC
- [add,del]_[consumer,producer] updated to takes both the consumer and
  producer handles. This is requested to combine info from both,
  typically to link the source irq owned by the producer with the gsi
  owned by the consumer (forwarded IRQ setup).
- new methods are added:
  x stop/resume: Those are needed for forwarding since the state change
    requires to entermingle actions at consumer, producer.
  x consumer update for posted interrupts
- On handshake, we now call connect, disconnect which features the more
  complex sequence.
- add irq on producer side

Signed-off-by: Eric Auger <eric.auger@linaro.org>

---

v1 -> v2:
- remove vfio_device, kvm, gsi, opaque fields included in v1 except common
- all those in can be retrieved with container_of in callbacks
---
 include/linux/irqbypass.h | 19 ++++++++++++++++---
 kernel/irq/bypass.c       | 44 ++++++++++++++++++++++++++++++++++++++++----
 2 files changed, 56 insertions(+), 7 deletions(-)

Comments

Paolo Bonzini July 6, 2015, 12:27 p.m. UTC | #1
On 06/07/2015 14:11, Eric Auger wrote:
> diff --git a/kernel/irq/bypass.c b/kernel/irq/bypass.c
> index 5d0f92b..efadbe5 100644
> --- a/kernel/irq/bypass.c
> +++ b/kernel/irq/bypass.c
> @@ -19,6 +19,42 @@ static LIST_HEAD(producers);
>  static LIST_HEAD(consumers);
>  static DEFINE_MUTEX(lock);
>  
> +/* lock must be hold when calling connect */

If a lock must be held while callbacks are called, you have to document
that producers and consumers must _not_ call back into the IRQ bypass
manager.  (If they have to, you have to document explicitly "This
function can be called from producer and consumer callbacks" whenever
relevant).

> +static void connect(struct irq_bypass_producer *prod,
> +		    struct irq_bypass_consumer *cons)
> +{
> +	if (prod->stop)
> +		prod->stop(prod);
> +	if (cons->stop)
> +		cons->stop(cons);
> +	if (prod->add_consumer)
> +		prod->add_consumer(prod, cons);
> +	if (cons->add_producer)
> +		cons->add_producer(cons, prod);
> +	if (cons->resume)
> +		cons->resume(cons);
> +	if (prod->resume)
> +		prod->resume(prod);
> +}
> +
> +/* lock must be hold when calling disconnect */
> +static void disconnect(struct irq_bypass_producer *prod,
> +		       struct irq_bypass_consumer *cons)
> +{
> +	if (prod->stop)
> +		prod->stop(prod);
> +	if (cons->stop)
> +		cons->stop(cons);
> +	if (cons->del_producer)
> +		cons->del_producer(cons, prod);
> +	if (prod->del_consumer)
> +		prod->del_consumer(prod, cons);
> +	if (cons->resume)
> +		cons->resume(cons);
> +	if (prod->resume)
> +		prod->resume(prod);
> +}
> +
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Eric Auger July 6, 2015, 3:35 p.m. UTC | #2
Hi Paolo,
On 07/06/2015 02:27 PM, Paolo Bonzini wrote:
> 
> 
> On 06/07/2015 14:11, Eric Auger wrote:
>> diff --git a/kernel/irq/bypass.c b/kernel/irq/bypass.c
>> index 5d0f92b..efadbe5 100644
>> --- a/kernel/irq/bypass.c
>> +++ b/kernel/irq/bypass.c
>> @@ -19,6 +19,42 @@ static LIST_HEAD(producers);
>>  static LIST_HEAD(consumers);
>>  static DEFINE_MUTEX(lock);
>>  
>> +/* lock must be hold when calling connect */
> 
> If a lock must be held while callbacks are called, you have to document
> that producers and consumers must _not_ call back into the IRQ bypass
> manager.  (If they have to, you have to document explicitly "This
> function can be called from producer and consumer callbacks" whenever
> relevant).
OK Thanks

Eric
> 
>> +static void connect(struct irq_bypass_producer *prod,
>> +		    struct irq_bypass_consumer *cons)
>> +{
>> +	if (prod->stop)
>> +		prod->stop(prod);
>> +	if (cons->stop)
>> +		cons->stop(cons);
>> +	if (prod->add_consumer)
>> +		prod->add_consumer(prod, cons);
>> +	if (cons->add_producer)
>> +		cons->add_producer(cons, prod);
>> +	if (cons->resume)
>> +		cons->resume(cons);
>> +	if (prod->resume)
>> +		prod->resume(prod);
>> +}
>> +
>> +/* lock must be hold when calling disconnect */
>> +static void disconnect(struct irq_bypass_producer *prod,
>> +		       struct irq_bypass_consumer *cons)
>> +{
>> +	if (prod->stop)
>> +		prod->stop(prod);
>> +	if (cons->stop)
>> +		cons->stop(cons);
>> +	if (cons->del_producer)
>> +		cons->del_producer(cons, prod);
>> +	if (prod->del_consumer)
>> +		prod->del_consumer(prod, cons);
>> +	if (cons->resume)
>> +		cons->resume(cons);
>> +	if (prod->resume)
>> +		prod->resume(prod);
>> +}
>> +

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Paolo Bonzini July 6, 2015, 3:57 p.m. UTC | #3
On 06/07/2015 17:35, Eric Auger wrote:
>>> diff --git a/kernel/irq/bypass.c b/kernel/irq/bypass.c
>>> >> index 5d0f92b..efadbe5 100644
>>> >> --- a/kernel/irq/bypass.c
>>> >> +++ b/kernel/irq/bypass.c
>>> >> @@ -19,6 +19,42 @@ static LIST_HEAD(producers);
>>> >>  static LIST_HEAD(consumers);
>>> >>  static DEFINE_MUTEX(lock);
>>> >>  
>>> >> +/* lock must be hold when calling connect */
>> > 
>> > If a lock must be held while callbacks are called, you have to document
>> > that producers and consumers must _not_ call back into the IRQ bypass
>> > manager.  (If they have to, you have to document explicitly "This
>> > function can be called from producer and consumer callbacks" whenever
>> > relevant).
> OK Thanks

Also, please document on functions that take the irq bypass mutex that
they can sleep.  In fact irq_bypass_{,un}register_{producer,consumer}
need kerneldoc comments.

The good thing is that this helps a bit forming a lock hierarchy across
the subsystems, for example irq bypass mutex outside vfio_platform_irq
spinlock, because you cannot have a spinlock inside the mutex.  I think
that all of your six callbacks are fine.

Paolo
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Eric Auger July 6, 2015, 5:09 p.m. UTC | #4
On 07/06/2015 05:57 PM, Paolo Bonzini wrote:
> 
> 
> On 06/07/2015 17:35, Eric Auger wrote:
>>>> diff --git a/kernel/irq/bypass.c b/kernel/irq/bypass.c
>>>>>> index 5d0f92b..efadbe5 100644
>>>>>> --- a/kernel/irq/bypass.c
>>>>>> +++ b/kernel/irq/bypass.c
>>>>>> @@ -19,6 +19,42 @@ static LIST_HEAD(producers);
>>>>>>  static LIST_HEAD(consumers);
>>>>>>  static DEFINE_MUTEX(lock);
>>>>>>  
>>>>>> +/* lock must be hold when calling connect */
>>>>
>>>> If a lock must be held while callbacks are called, you have to document
>>>> that producers and consumers must _not_ call back into the IRQ bypass
>>>> manager.  (If they have to, you have to document explicitly "This
>>>> function can be called from producer and consumer callbacks" whenever
>>>> relevant).
>> OK Thanks
> 
> Also, please document on functions that take the irq bypass mutex that
> they can sleep.  In fact irq_bypass_{,un}register_{producer,consumer}
> need kerneldoc comments.
> 
> The good thing is that this helps a bit forming a lock hierarchy across
> the subsystems, for example irq bypass mutex outside vfio_platform_irq
> spinlock, because you cannot have a spinlock inside the mutex.  I think
> that all of your six callbacks are fine.

arghh, no that's wrong then. I have plenty of them in the KVM/arm vgic
part :-(

Eric
> 
> Paolo
> 

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Paolo Bonzini July 6, 2015, 5:41 p.m. UTC | #5
On 06/07/2015 19:09, Eric Auger wrote:
>> > The good thing is that this helps a bit forming a lock hierarchy across
>> > the subsystems, for example irq bypass mutex outside vfio_platform_irq
>> > spinlock, because you cannot have a spinlock inside the mutex.  I think
>> > that all of your six callbacks are fine.
> arghh, no that's wrong then. I have plenty of them in the KVM/arm vgic
> part :-(

I checked and it's right...

/me rereads

AAAARGH.  You cannot have a mutex inside a spinlock.  What you're doing
is fine.

Paolo
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Eric Auger July 7, 2015, 7:10 a.m. UTC | #6
On 07/06/2015 07:41 PM, Paolo Bonzini wrote:
> 
> 
> On 06/07/2015 19:09, Eric Auger wrote:
>>>> The good thing is that this helps a bit forming a lock hierarchy across
>>>> the subsystems, for example irq bypass mutex outside vfio_platform_irq
>>>> spinlock, because you cannot have a spinlock inside the mutex.  I think
>>>> that all of your six callbacks are fine.
>> arghh, no that's wrong then. I have plenty of them in the KVM/arm vgic
>> part :-(
> 
> I checked and it's right...
> 
> /me rereads
> 
> AAAARGH.  You cannot have a mutex inside a spinlock.  What you're doing
> is fine.
Sweated up (+ heat wave in France). Was about to read again the
"concurrency and race conditions" chapter of the linux driver bible.
Might be worth anyway ;-)

Many thanks for the review

Eric
> 
> Paolo
> 

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Paolo Bonzini July 7, 2015, 8:58 a.m. UTC | #7
On 07/07/2015 09:10, Eric Auger wrote:
> On 07/06/2015 07:41 PM, Paolo Bonzini wrote:
>>
>>
>> On 06/07/2015 19:09, Eric Auger wrote:
>>>>> The good thing is that this helps a bit forming a lock hierarchy across
>>>>> the subsystems, for example irq bypass mutex outside vfio_platform_irq
>>>>> spinlock, because you cannot have a spinlock inside the mutex.  I think
>>>>> that all of your six callbacks are fine.
>>> arghh, no that's wrong then. I have plenty of them in the KVM/arm vgic
>>> part :-(
>>
>> I checked and it's right...
>>
>> /me rereads
>>
>> AAAARGH.  You cannot have a mutex inside a spinlock.  What you're doing
>> is fine.
>
> Sweated up (+ heat wave in France).

Same here, I also can blame the heat wave for the mistakes. :)

Paolo
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Wu, Feng July 7, 2015, 10:58 a.m. UTC | #8
> -----Original Message-----
> From: Eric Auger [mailto:eric.auger@linaro.org]
> Sent: Monday, July 06, 2015 8:11 PM
> To: eric.auger@st.com; eric.auger@linaro.org;
> linux-arm-kernel@lists.infradead.org; kvmarm@lists.cs.columbia.edu;
> kvm@vger.kernel.org; christoffer.dall@linaro.org; marc.zyngier@arm.com;
> alex.williamson@redhat.com; pbonzini@redhat.com; avi.kivity@gmail.com;
> mtosatti@redhat.com; Wu, Feng; joro@8bytes.org;
> b.reynal@virtualopensystems.com
> Cc: linux-kernel@vger.kernel.org; patches@linaro.org
> Subject: [RFC v2 3/6] irq: bypass: Extend skeleton for ARM forwarding control
> 
> - [add,del]_[consumer,producer] updated to takes both the consumer and
>   producer handles. This is requested to combine info from both,
>   typically to link the source irq owned by the producer with the gsi
>   owned by the consumer (forwarded IRQ setup).
> - new methods are added:
>   x stop/resume: Those are needed for forwarding since the state change
>     requires to entermingle actions at consumer, producer.
>   x consumer update for posted interrupts
> - On handshake, we now call connect, disconnect which features the more
>   complex sequence.
> - add irq on producer side
> 
> Signed-off-by: Eric Auger <eric.auger@linaro.org>
> 
> ---
> 
> v1 -> v2:
> - remove vfio_device, kvm, gsi, opaque fields included in v1 except common
> - all those in can be retrieved with container_of in callbacks
> ---
>  include/linux/irqbypass.h | 19 ++++++++++++++++---
>  kernel/irq/bypass.c       | 44
> ++++++++++++++++++++++++++++++++++++++++----
>  2 files changed, 56 insertions(+), 7 deletions(-)
> 
> diff --git a/include/linux/irqbypass.h b/include/linux/irqbypass.h
> index 718508e..8f62235 100644
> --- a/include/linux/irqbypass.h
> +++ b/include/linux/irqbypass.h
> @@ -3,17 +3,30 @@
> 
>  #include <linux/list.h>
> 
> +struct irq_bypass_consumer;
> +
>  struct irq_bypass_producer {
>  	struct list_head node;
>  	void *token;
> -	/* TBD */
> +	int irq; /* linux irq */
> +	void (*stop)(struct irq_bypass_producer *);
> +	void (*resume)(struct irq_bypass_producer *);
> +	void (*add_consumer)(struct irq_bypass_producer *,
> +			     struct irq_bypass_consumer *);
> +	void (*del_consumer)(struct irq_bypass_producer *,
> +			     struct irq_bypass_consumer *);
>  };
> 
>  struct irq_bypass_consumer {
>  	struct list_head node;
>  	void *token;

Can we add a pointer to ' struct irq_bypass_producer ', and
assign it when connecting, de-assign it when disconnecting.
since in some case, I need to update IRTE from the consumer
side, where I cannot get the related producer info (I need irq info)
without iterating it again.

Thanks,
Feng

> -	void (*add_producer)(struct irq_bypass_producer *);
> -	void (*del_producer)(struct irq_bypass_producer *);
> +	void (*stop)(struct irq_bypass_consumer *);
> +	void (*resume)(struct irq_bypass_consumer *);
> +	void (*add_producer)(struct irq_bypass_consumer *,
> +			     struct irq_bypass_producer *);
> +	void (*del_producer)(struct irq_bypass_consumer *,
> +			     struct irq_bypass_producer *);
> +	void (*update)(struct irq_bypass_consumer *);
>  };
> 
>  int irq_bypass_register_producer(struct irq_bypass_producer *);
> diff --git a/kernel/irq/bypass.c b/kernel/irq/bypass.c
> index 5d0f92b..efadbe5 100644
> --- a/kernel/irq/bypass.c
> +++ b/kernel/irq/bypass.c
> @@ -19,6 +19,42 @@ static LIST_HEAD(producers);
>  static LIST_HEAD(consumers);
>  static DEFINE_MUTEX(lock);
> 
> +/* lock must be hold when calling connect */
> +static void connect(struct irq_bypass_producer *prod,
> +		    struct irq_bypass_consumer *cons)
> +{
> +	if (prod->stop)
> +		prod->stop(prod);
> +	if (cons->stop)
> +		cons->stop(cons);
> +	if (prod->add_consumer)
> +		prod->add_consumer(prod, cons);
> +	if (cons->add_producer)
> +		cons->add_producer(cons, prod);
> +	if (cons->resume)
> +		cons->resume(cons);
> +	if (prod->resume)
> +		prod->resume(prod);
> +}
> +
> +/* lock must be hold when calling disconnect */
> +static void disconnect(struct irq_bypass_producer *prod,
> +		       struct irq_bypass_consumer *cons)
> +{
> +	if (prod->stop)
> +		prod->stop(prod);
> +	if (cons->stop)
> +		cons->stop(cons);
> +	if (cons->del_producer)
> +		cons->del_producer(cons, prod);
> +	if (prod->del_consumer)
> +		prod->del_consumer(prod, cons);
> +	if (cons->resume)
> +		cons->resume(cons);
> +	if (prod->resume)
> +		prod->resume(prod);
> +}
> +
>  int irq_bypass_register_producer(struct irq_bypass_producer *producer)
>  {
>  	struct irq_bypass_producer *tmp;
> @@ -38,7 +74,7 @@ int irq_bypass_register_producer(struct
> irq_bypass_producer *producer)
> 
>  	list_for_each_entry(consumer, &consumers, node) {
>  		if (consumer->token == producer->token) {
> -			consumer->add_producer(producer);
> +			connect(producer, consumer);
>  			break;
>  		}
>  	}
> @@ -56,7 +92,7 @@ void irq_bypass_unregister_producer(struct
> irq_bypass_producer *producer)
> 
>  	list_for_each_entry(consumer, &consumers, node) {
>  		if (consumer->token == producer->token) {
> -			consumer->del_producer(producer);
> +			disconnect(producer, consumer);
>  			break;
>  		}
>  	}
> @@ -86,7 +122,7 @@ int irq_bypass_register_consumer(struct
> irq_bypass_consumer *consumer)
> 
>  	list_for_each_entry(producer, &producers, node) {
>  		if (producer->token == consumer->token) {
> -			consumer->add_producer(producer);
> +			connect(producer, consumer);
>  			break;
>  		}
>  	}
> @@ -104,7 +140,7 @@ void irq_bypass_unregister_consumer(struct
> irq_bypass_consumer *consumer)
> 
>  	list_for_each_entry(producer, &producers, node) {
>  		if (producer->token == consumer->token) {
> -			consumer->del_producer(producer);
> +			disconnect(producer, consumer);
>  			break;
>  		}
>  	}
> --
> 1.9.1

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Paolo Bonzini July 7, 2015, 11 a.m. UTC | #9
On 07/07/2015 12:58, Wu, Feng wrote:
> 
> 
>> -----Original Message-----
>> From: Eric Auger [mailto:eric.auger@linaro.org]
>> Sent: Monday, July 06, 2015 8:11 PM
>> To: eric.auger@st.com; eric.auger@linaro.org;
>> linux-arm-kernel@lists.infradead.org; kvmarm@lists.cs.columbia.edu;
>> kvm@vger.kernel.org; christoffer.dall@linaro.org; marc.zyngier@arm.com;
>> alex.williamson@redhat.com; pbonzini@redhat.com; avi.kivity@gmail.com;
>> mtosatti@redhat.com; Wu, Feng; joro@8bytes.org;
>> b.reynal@virtualopensystems.com
>> Cc: linux-kernel@vger.kernel.org; patches@linaro.org
>> Subject: [RFC v2 3/6] irq: bypass: Extend skeleton for ARM forwarding control
>>
>> - [add,del]_[consumer,producer] updated to takes both the consumer and
>>   producer handles. This is requested to combine info from both,
>>   typically to link the source irq owned by the producer with the gsi
>>   owned by the consumer (forwarded IRQ setup).
>> - new methods are added:
>>   x stop/resume: Those are needed for forwarding since the state change
>>     requires to entermingle actions at consumer, producer.
>>   x consumer update for posted interrupts
>> - On handshake, we now call connect, disconnect which features the more
>>   complex sequence.
>> - add irq on producer side
>>
>> Signed-off-by: Eric Auger <eric.auger@linaro.org>
>>
>> ---
>>
>> v1 -> v2:
>> - remove vfio_device, kvm, gsi, opaque fields included in v1 except common
>> - all those in can be retrieved with container_of in callbacks
>> ---
>>  include/linux/irqbypass.h | 19 ++++++++++++++++---
>>  kernel/irq/bypass.c       | 44
>> ++++++++++++++++++++++++++++++++++++++++----
>>  2 files changed, 56 insertions(+), 7 deletions(-)
>>
>> diff --git a/include/linux/irqbypass.h b/include/linux/irqbypass.h
>> index 718508e..8f62235 100644
>> --- a/include/linux/irqbypass.h
>> +++ b/include/linux/irqbypass.h
>> @@ -3,17 +3,30 @@
>>
>>  #include <linux/list.h>
>>
>> +struct irq_bypass_consumer;
>> +
>>  struct irq_bypass_producer {
>>  	struct list_head node;
>>  	void *token;
>> -	/* TBD */
>> +	int irq; /* linux irq */
>> +	void (*stop)(struct irq_bypass_producer *);
>> +	void (*resume)(struct irq_bypass_producer *);
>> +	void (*add_consumer)(struct irq_bypass_producer *,
>> +			     struct irq_bypass_consumer *);
>> +	void (*del_consumer)(struct irq_bypass_producer *,
>> +			     struct irq_bypass_consumer *);
>>  };
>>
>>  struct irq_bypass_consumer {
>>  	struct list_head node;
>>  	void *token;
> 
> Can we add a pointer to ' struct irq_bypass_producer ', and
> assign it when connecting, de-assign it when disconnecting.
> since in some case, I need to update IRTE from the consumer
> side, where I cannot get the related producer info (I need irq info)
> without iterating it again.

You can use container_of to add it to your own struct, e.g.

	struct irq_bypass_consumer cons;
	struct irq_bypass_producer *prod;

Paolo

> Thanks,
> Feng
> 
>> -	void (*add_producer)(struct irq_bypass_producer *);
>> -	void (*del_producer)(struct irq_bypass_producer *);
>> +	void (*stop)(struct irq_bypass_consumer *);
>> +	void (*resume)(struct irq_bypass_consumer *);
>> +	void (*add_producer)(struct irq_bypass_consumer *,
>> +			     struct irq_bypass_producer *);
>> +	void (*del_producer)(struct irq_bypass_consumer *,
>> +			     struct irq_bypass_producer *);
>> +	void (*update)(struct irq_bypass_consumer *);
>>  };
>>
>>  int irq_bypass_register_producer(struct irq_bypass_producer *);
>> diff --git a/kernel/irq/bypass.c b/kernel/irq/bypass.c
>> index 5d0f92b..efadbe5 100644
>> --- a/kernel/irq/bypass.c
>> +++ b/kernel/irq/bypass.c
>> @@ -19,6 +19,42 @@ static LIST_HEAD(producers);
>>  static LIST_HEAD(consumers);
>>  static DEFINE_MUTEX(lock);
>>
>> +/* lock must be hold when calling connect */
>> +static void connect(struct irq_bypass_producer *prod,
>> +		    struct irq_bypass_consumer *cons)
>> +{
>> +	if (prod->stop)
>> +		prod->stop(prod);
>> +	if (cons->stop)
>> +		cons->stop(cons);
>> +	if (prod->add_consumer)
>> +		prod->add_consumer(prod, cons);
>> +	if (cons->add_producer)
>> +		cons->add_producer(cons, prod);
>> +	if (cons->resume)
>> +		cons->resume(cons);
>> +	if (prod->resume)
>> +		prod->resume(prod);
>> +}
>> +
>> +/* lock must be hold when calling disconnect */
>> +static void disconnect(struct irq_bypass_producer *prod,
>> +		       struct irq_bypass_consumer *cons)
>> +{
>> +	if (prod->stop)
>> +		prod->stop(prod);
>> +	if (cons->stop)
>> +		cons->stop(cons);
>> +	if (cons->del_producer)
>> +		cons->del_producer(cons, prod);
>> +	if (prod->del_consumer)
>> +		prod->del_consumer(prod, cons);
>> +	if (cons->resume)
>> +		cons->resume(cons);
>> +	if (prod->resume)
>> +		prod->resume(prod);
>> +}
>> +
>>  int irq_bypass_register_producer(struct irq_bypass_producer *producer)
>>  {
>>  	struct irq_bypass_producer *tmp;
>> @@ -38,7 +74,7 @@ int irq_bypass_register_producer(struct
>> irq_bypass_producer *producer)
>>
>>  	list_for_each_entry(consumer, &consumers, node) {
>>  		if (consumer->token == producer->token) {
>> -			consumer->add_producer(producer);
>> +			connect(producer, consumer);
>>  			break;
>>  		}
>>  	}
>> @@ -56,7 +92,7 @@ void irq_bypass_unregister_producer(struct
>> irq_bypass_producer *producer)
>>
>>  	list_for_each_entry(consumer, &consumers, node) {
>>  		if (consumer->token == producer->token) {
>> -			consumer->del_producer(producer);
>> +			disconnect(producer, consumer);
>>  			break;
>>  		}
>>  	}
>> @@ -86,7 +122,7 @@ int irq_bypass_register_consumer(struct
>> irq_bypass_consumer *consumer)
>>
>>  	list_for_each_entry(producer, &producers, node) {
>>  		if (producer->token == consumer->token) {
>> -			consumer->add_producer(producer);
>> +			connect(producer, consumer);
>>  			break;
>>  		}
>>  	}
>> @@ -104,7 +140,7 @@ void irq_bypass_unregister_consumer(struct
>> irq_bypass_consumer *consumer)
>>
>>  	list_for_each_entry(producer, &producers, node) {
>>  		if (producer->token == consumer->token) {
>> -			consumer->del_producer(producer);
>> +			disconnect(producer, consumer);
>>  			break;
>>  		}
>>  	}
>> --
>> 1.9.1
> 
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Wu, Feng July 7, 2015, 11:13 a.m. UTC | #10
> -----Original Message-----
> From: Paolo Bonzini [mailto:pbonzini@redhat.com]
> Sent: Tuesday, July 07, 2015 7:01 PM
> To: Wu, Feng; Eric Auger; eric.auger@st.com;
> linux-arm-kernel@lists.infradead.org; kvmarm@lists.cs.columbia.edu;
> kvm@vger.kernel.org; christoffer.dall@linaro.org; marc.zyngier@arm.com;
> alex.williamson@redhat.com; avi.kivity@gmail.com; mtosatti@redhat.com;
> joro@8bytes.org; b.reynal@virtualopensystems.com
> Cc: linux-kernel@vger.kernel.org; patches@linaro.org
> Subject: Re: [RFC v2 3/6] irq: bypass: Extend skeleton for ARM forwarding
> control
> 
> 
> 
> On 07/07/2015 12:58, Wu, Feng wrote:
> >
> >
> >> -----Original Message-----
> >> From: Eric Auger [mailto:eric.auger@linaro.org]
> >> Sent: Monday, July 06, 2015 8:11 PM
> >> To: eric.auger@st.com; eric.auger@linaro.org;
> >> linux-arm-kernel@lists.infradead.org; kvmarm@lists.cs.columbia.edu;
> >> kvm@vger.kernel.org; christoffer.dall@linaro.org; marc.zyngier@arm.com;
> >> alex.williamson@redhat.com; pbonzini@redhat.com; avi.kivity@gmail.com;
> >> mtosatti@redhat.com; Wu, Feng; joro@8bytes.org;
> >> b.reynal@virtualopensystems.com
> >> Cc: linux-kernel@vger.kernel.org; patches@linaro.org
> >> Subject: [RFC v2 3/6] irq: bypass: Extend skeleton for ARM forwarding
> control
> >>
> >> - [add,del]_[consumer,producer] updated to takes both the consumer and
> >>   producer handles. This is requested to combine info from both,
> >>   typically to link the source irq owned by the producer with the gsi
> >>   owned by the consumer (forwarded IRQ setup).
> >> - new methods are added:
> >>   x stop/resume: Those are needed for forwarding since the state change
> >>     requires to entermingle actions at consumer, producer.
> >>   x consumer update for posted interrupts
> >> - On handshake, we now call connect, disconnect which features the more
> >>   complex sequence.
> >> - add irq on producer side
> >>
> >> Signed-off-by: Eric Auger <eric.auger@linaro.org>
> >>
> >> ---
> >>
> >> v1 -> v2:
> >> - remove vfio_device, kvm, gsi, opaque fields included in v1 except common
> >> - all those in can be retrieved with container_of in callbacks
> >> ---
> >>  include/linux/irqbypass.h | 19 ++++++++++++++++---
> >>  kernel/irq/bypass.c       | 44
> >> ++++++++++++++++++++++++++++++++++++++++----
> >>  2 files changed, 56 insertions(+), 7 deletions(-)
> >>
> >> diff --git a/include/linux/irqbypass.h b/include/linux/irqbypass.h
> >> index 718508e..8f62235 100644
> >> --- a/include/linux/irqbypass.h
> >> +++ b/include/linux/irqbypass.h
> >> @@ -3,17 +3,30 @@
> >>
> >>  #include <linux/list.h>
> >>
> >> +struct irq_bypass_consumer;
> >> +
> >>  struct irq_bypass_producer {
> >>  	struct list_head node;
> >>  	void *token;
> >> -	/* TBD */
> >> +	int irq; /* linux irq */
> >> +	void (*stop)(struct irq_bypass_producer *);
> >> +	void (*resume)(struct irq_bypass_producer *);
> >> +	void (*add_consumer)(struct irq_bypass_producer *,
> >> +			     struct irq_bypass_consumer *);
> >> +	void (*del_consumer)(struct irq_bypass_producer *,
> >> +			     struct irq_bypass_consumer *);
> >>  };
> >>
> >>  struct irq_bypass_consumer {
> >>  	struct list_head node;
> >>  	void *token;
> >
> > Can we add a pointer to ' struct irq_bypass_producer ', and
> > assign it when connecting, de-assign it when disconnecting.
> > since in some case, I need to update IRTE from the consumer
> > side, where I cannot get the related producer info (I need irq info)
> > without iterating it again.
> 
> You can use container_of to add it to your own struct, e.g.
> 
> 	struct irq_bypass_consumer cons;
> 	struct irq_bypass_producer *prod;

Do you mean this:

struct kvm_kernel_irqfd {
	
	......

	struct irq_bypass_consumer cons;
	struct irq_bypass_producer *prod;
};

Thanks,
Feng

> 
> Paolo
> 
> > Thanks,
> > Feng
> >
> >> -	void (*add_producer)(struct irq_bypass_producer *);
> >> -	void (*del_producer)(struct irq_bypass_producer *);
> >> +	void (*stop)(struct irq_bypass_consumer *);
> >> +	void (*resume)(struct irq_bypass_consumer *);
> >> +	void (*add_producer)(struct irq_bypass_consumer *,
> >> +			     struct irq_bypass_producer *);
> >> +	void (*del_producer)(struct irq_bypass_consumer *,
> >> +			     struct irq_bypass_producer *);
> >> +	void (*update)(struct irq_bypass_consumer *);
> >>  };
> >>
> >>  int irq_bypass_register_producer(struct irq_bypass_producer *);
> >> diff --git a/kernel/irq/bypass.c b/kernel/irq/bypass.c
> >> index 5d0f92b..efadbe5 100644
> >> --- a/kernel/irq/bypass.c
> >> +++ b/kernel/irq/bypass.c
> >> @@ -19,6 +19,42 @@ static LIST_HEAD(producers);
> >>  static LIST_HEAD(consumers);
> >>  static DEFINE_MUTEX(lock);
> >>
> >> +/* lock must be hold when calling connect */
> >> +static void connect(struct irq_bypass_producer *prod,
> >> +		    struct irq_bypass_consumer *cons)
> >> +{
> >> +	if (prod->stop)
> >> +		prod->stop(prod);
> >> +	if (cons->stop)
> >> +		cons->stop(cons);
> >> +	if (prod->add_consumer)
> >> +		prod->add_consumer(prod, cons);
> >> +	if (cons->add_producer)
> >> +		cons->add_producer(cons, prod);
> >> +	if (cons->resume)
> >> +		cons->resume(cons);
> >> +	if (prod->resume)
> >> +		prod->resume(prod);
> >> +}
> >> +
> >> +/* lock must be hold when calling disconnect */
> >> +static void disconnect(struct irq_bypass_producer *prod,
> >> +		       struct irq_bypass_consumer *cons)
> >> +{
> >> +	if (prod->stop)
> >> +		prod->stop(prod);
> >> +	if (cons->stop)
> >> +		cons->stop(cons);
> >> +	if (cons->del_producer)
> >> +		cons->del_producer(cons, prod);
> >> +	if (prod->del_consumer)
> >> +		prod->del_consumer(prod, cons);
> >> +	if (cons->resume)
> >> +		cons->resume(cons);
> >> +	if (prod->resume)
> >> +		prod->resume(prod);
> >> +}
> >> +
> >>  int irq_bypass_register_producer(struct irq_bypass_producer *producer)
> >>  {
> >>  	struct irq_bypass_producer *tmp;
> >> @@ -38,7 +74,7 @@ int irq_bypass_register_producer(struct
> >> irq_bypass_producer *producer)
> >>
> >>  	list_for_each_entry(consumer, &consumers, node) {
> >>  		if (consumer->token == producer->token) {
> >> -			consumer->add_producer(producer);
> >> +			connect(producer, consumer);
> >>  			break;
> >>  		}
> >>  	}
> >> @@ -56,7 +92,7 @@ void irq_bypass_unregister_producer(struct
> >> irq_bypass_producer *producer)
> >>
> >>  	list_for_each_entry(consumer, &consumers, node) {
> >>  		if (consumer->token == producer->token) {
> >> -			consumer->del_producer(producer);
> >> +			disconnect(producer, consumer);
> >>  			break;
> >>  		}
> >>  	}
> >> @@ -86,7 +122,7 @@ int irq_bypass_register_consumer(struct
> >> irq_bypass_consumer *consumer)
> >>
> >>  	list_for_each_entry(producer, &producers, node) {
> >>  		if (producer->token == consumer->token) {
> >> -			consumer->add_producer(producer);
> >> +			connect(producer, consumer);
> >>  			break;
> >>  		}
> >>  	}
> >> @@ -104,7 +140,7 @@ void irq_bypass_unregister_consumer(struct
> >> irq_bypass_consumer *consumer)
> >>
> >>  	list_for_each_entry(producer, &producers, node) {
> >>  		if (producer->token == consumer->token) {
> >> -			consumer->del_producer(producer);
> >> +			disconnect(producer, consumer);
> >>  			break;
> >>  		}
> >>  	}
> >> --
> >> 1.9.1
> >
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Paolo Bonzini July 7, 2015, 11:13 a.m. UTC | #11
On 07/07/2015 13:13, Wu, Feng wrote:
>> > You can use container_of to add it to your own struct, e.g.
>> > 
>> > 	struct irq_bypass_consumer cons;
>> > 	struct irq_bypass_producer *prod;
> Do you mean this:
> 
> struct kvm_kernel_irqfd {
> 	
> 	......
> 
> 	struct irq_bypass_consumer cons;
> 	struct irq_bypass_producer *prod;
> };

Yes.

Paolo
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diff mbox

Patch

diff --git a/include/linux/irqbypass.h b/include/linux/irqbypass.h
index 718508e..8f62235 100644
--- a/include/linux/irqbypass.h
+++ b/include/linux/irqbypass.h
@@ -3,17 +3,30 @@ 
 
 #include <linux/list.h>
 
+struct irq_bypass_consumer;
+
 struct irq_bypass_producer {
 	struct list_head node;
 	void *token;
-	/* TBD */
+	int irq; /* linux irq */
+	void (*stop)(struct irq_bypass_producer *);
+	void (*resume)(struct irq_bypass_producer *);
+	void (*add_consumer)(struct irq_bypass_producer *,
+			     struct irq_bypass_consumer *);
+	void (*del_consumer)(struct irq_bypass_producer *,
+			     struct irq_bypass_consumer *);
 };
 
 struct irq_bypass_consumer {
 	struct list_head node;
 	void *token;
-	void (*add_producer)(struct irq_bypass_producer *);
-	void (*del_producer)(struct irq_bypass_producer *);
+	void (*stop)(struct irq_bypass_consumer *);
+	void (*resume)(struct irq_bypass_consumer *);
+	void (*add_producer)(struct irq_bypass_consumer *,
+			     struct irq_bypass_producer *);
+	void (*del_producer)(struct irq_bypass_consumer *,
+			     struct irq_bypass_producer *);
+	void (*update)(struct irq_bypass_consumer *);
 };
 
 int irq_bypass_register_producer(struct irq_bypass_producer *);
diff --git a/kernel/irq/bypass.c b/kernel/irq/bypass.c
index 5d0f92b..efadbe5 100644
--- a/kernel/irq/bypass.c
+++ b/kernel/irq/bypass.c
@@ -19,6 +19,42 @@  static LIST_HEAD(producers);
 static LIST_HEAD(consumers);
 static DEFINE_MUTEX(lock);
 
+/* lock must be hold when calling connect */
+static void connect(struct irq_bypass_producer *prod,
+		    struct irq_bypass_consumer *cons)
+{
+	if (prod->stop)
+		prod->stop(prod);
+	if (cons->stop)
+		cons->stop(cons);
+	if (prod->add_consumer)
+		prod->add_consumer(prod, cons);
+	if (cons->add_producer)
+		cons->add_producer(cons, prod);
+	if (cons->resume)
+		cons->resume(cons);
+	if (prod->resume)
+		prod->resume(prod);
+}
+
+/* lock must be hold when calling disconnect */
+static void disconnect(struct irq_bypass_producer *prod,
+		       struct irq_bypass_consumer *cons)
+{
+	if (prod->stop)
+		prod->stop(prod);
+	if (cons->stop)
+		cons->stop(cons);
+	if (cons->del_producer)
+		cons->del_producer(cons, prod);
+	if (prod->del_consumer)
+		prod->del_consumer(prod, cons);
+	if (cons->resume)
+		cons->resume(cons);
+	if (prod->resume)
+		prod->resume(prod);
+}
+
 int irq_bypass_register_producer(struct irq_bypass_producer *producer)
 {
 	struct irq_bypass_producer *tmp;
@@ -38,7 +74,7 @@  int irq_bypass_register_producer(struct irq_bypass_producer *producer)
 
 	list_for_each_entry(consumer, &consumers, node) {
 		if (consumer->token == producer->token) {
-			consumer->add_producer(producer);
+			connect(producer, consumer);
 			break;
 		}
 	}
@@ -56,7 +92,7 @@  void irq_bypass_unregister_producer(struct irq_bypass_producer *producer)
 
 	list_for_each_entry(consumer, &consumers, node) {
 		if (consumer->token == producer->token) {
-			consumer->del_producer(producer);
+			disconnect(producer, consumer);
 			break;
 		}
 	}
@@ -86,7 +122,7 @@  int irq_bypass_register_consumer(struct irq_bypass_consumer *consumer)
 
 	list_for_each_entry(producer, &producers, node) {
 		if (producer->token == consumer->token) {
-			consumer->add_producer(producer);
+			connect(producer, consumer);
 			break;
 		}
 	}
@@ -104,7 +140,7 @@  void irq_bypass_unregister_consumer(struct irq_bypass_consumer *consumer)
 
 	list_for_each_entry(producer, &producers, node) {
 		if (producer->token == consumer->token) {
-			consumer->del_producer(producer);
+			disconnect(producer, consumer);
 			break;
 		}
 	}