[v2,4/7] irqchip/gic-v3-its: Don't map the MSI page in its_irq_compose_msi_msg()

its_irq_compose_msi_msg() may be called from non-preemptible context.
However, on RT, iommu_dma_map_msi_msg requires to be called from a
preemptible context.

A recent change split iommu_dma_map_msi_msg() in two new functions:
one that should be called in preemptible context, the other does
not have any requirement.

The GICv3 ITS driver is reworked to avoid executing preemptible code in
non-preemptible context. This can be achieved by preparing the MSI
maping when allocating the MSI interrupt.

Signed-off-by: Julien Grall <julien.grall@arm.com>


---
    Changes in v2:
        - Rework the commit message to use imperative mood
---
 drivers/irqchip/irq-gic-v3-its.c | 5 ++++-
 1 file changed, 4 insertions(+), 1 deletion(-)

-- 
2.11.0

Hi Julien,

On 4/29/19 4:44 PM, Julien Grall wrote:
> its_irq_compose_msi_msg() may be called from non-preemptible context.

> However, on RT, iommu_dma_map_msi_msg requires to be called from a

> preemptible context.

> 

> A recent change split iommu_dma_map_msi_msg() in two new functions:

> one that should be called in preemptible context, the other does

> not have any requirement.

> 

> The GICv3 ITS driver is reworked to avoid executing preemptible code in

> non-preemptible context. This can be achieved by preparing the MSI

> maping when allocating the MSI interrupt.

mapping
> 

> Signed-off-by: Julien Grall <julien.grall@arm.com>

> 

> ---

>     Changes in v2:

>         - Rework the commit message to use imperative mood

> ---

>  drivers/irqchip/irq-gic-v3-its.c | 5 ++++-

>  1 file changed, 4 insertions(+), 1 deletion(-)

> 

> diff --git a/drivers/irqchip/irq-gic-v3-its.c b/drivers/irqchip/irq-gic-v3-its.c

> index 7577755bdcf4..12ddbcfe1b1e 100644

> --- a/drivers/irqchip/irq-gic-v3-its.c

> +++ b/drivers/irqchip/irq-gic-v3-its.c

> @@ -1179,7 +1179,7 @@ static void its_irq_compose_msi_msg(struct irq_data *d, struct msi_msg *msg)

>  	msg->address_hi		= upper_32_bits(addr);

>  	msg->data		= its_get_event_id(d);

>  

> -	iommu_dma_map_msi_msg(d->irq, msg);

> +	iommu_dma_compose_msi_msg(irq_data_get_msi_desc(d), msg);

>  }

>  

>  static int its_irq_set_irqchip_state(struct irq_data *d,

> @@ -2566,6 +2566,7 @@ static int its_irq_domain_alloc(struct irq_domain *domain, unsigned int virq,

>  {

>  	msi_alloc_info_t *info = args;

>  	struct its_device *its_dev = info->scratchpad[0].ptr;

> +	struct its_node *its = its_dev->its;

>  	irq_hw_number_t hwirq;

>  	int err;

>  	int i;

> @@ -2574,6 +2575,8 @@ static int its_irq_domain_alloc(struct irq_domain *domain, unsigned int virq,

>  	if (err)

>  		return err;

>  

> +	err = iommu_dma_prepare_msi(info->desc, its->get_msi_base(its_dev));

Test err as in gicv2m driver?
> +

>  	for (i = 0; i < nr_irqs; i++) {

>  		err = its_irq_gic_domain_alloc(domain, virq + i, hwirq + i);

>  		if (err)

> 

Besides
Reviewed-by: Eric Auger <eric.auger@redhat.com>


Thanks

Eric

On 30/04/2019 13:34, Auger Eric wrote:
> Hi Julien,


Hi Eric,

Thank you for the review!

> 

> On 4/29/19 4:44 PM, Julien Grall wrote:

>> its_irq_compose_msi_msg() may be called from non-preemptible context.

>> However, on RT, iommu_dma_map_msi_msg requires to be called from a

>> preemptible context.

>>

>> A recent change split iommu_dma_map_msi_msg() in two new functions:

>> one that should be called in preemptible context, the other does

>> not have any requirement.

>>

>> The GICv3 ITS driver is reworked to avoid executing preemptible code in

>> non-preemptible context. This can be achieved by preparing the MSI

>> maping when allocating the MSI interrupt.

> mapping

>>

>> Signed-off-by: Julien Grall <julien.grall@arm.com>

>>

>> ---

>>      Changes in v2:

>>          - Rework the commit message to use imperative mood

>> ---

>>   drivers/irqchip/irq-gic-v3-its.c | 5 ++++-

>>   1 file changed, 4 insertions(+), 1 deletion(-)

>>

>> diff --git a/drivers/irqchip/irq-gic-v3-its.c b/drivers/irqchip/irq-gic-v3-its.c

>> index 7577755bdcf4..12ddbcfe1b1e 100644

>> --- a/drivers/irqchip/irq-gic-v3-its.c

>> +++ b/drivers/irqchip/irq-gic-v3-its.c

>> @@ -1179,7 +1179,7 @@ static void its_irq_compose_msi_msg(struct irq_data *d, struct msi_msg *msg)

>>   	msg->address_hi		= upper_32_bits(addr);

>>   	msg->data		= its_get_event_id(d);

>>   

>> -	iommu_dma_map_msi_msg(d->irq, msg);

>> +	iommu_dma_compose_msi_msg(irq_data_get_msi_desc(d), msg);

>>   }

>>   

>>   static int its_irq_set_irqchip_state(struct irq_data *d,

>> @@ -2566,6 +2566,7 @@ static int its_irq_domain_alloc(struct irq_domain *domain, unsigned int virq,

>>   {

>>   	msi_alloc_info_t *info = args;

>>   	struct its_device *its_dev = info->scratchpad[0].ptr;

>> +	struct its_node *its = its_dev->its;

>>   	irq_hw_number_t hwirq;

>>   	int err;

>>   	int i;

>> @@ -2574,6 +2575,8 @@ static int its_irq_domain_alloc(struct irq_domain *domain, unsigned int virq,

>>   	if (err)

>>   		return err;

>>   

>> +	err = iommu_dma_prepare_msi(info->desc, its->get_msi_base(its_dev));

> Test err as in gicv2m driver?


Hmmm yes. Marc, do you want me to respin the patch?

Cheers,

-- 
Julien Grall

On 01/05/2019 12:14, Julien Grall wrote:
> On 30/04/2019 13:34, Auger Eric wrote:

>> Hi Julien,

> 

> Hi Eric,

> 

> Thank you for the review!

> 

>>

>> On 4/29/19 4:44 PM, Julien Grall wrote:

>>> its_irq_compose_msi_msg() may be called from non-preemptible context.

>>> However, on RT, iommu_dma_map_msi_msg requires to be called from a

>>> preemptible context.

>>>

>>> A recent change split iommu_dma_map_msi_msg() in two new functions:

>>> one that should be called in preemptible context, the other does

>>> not have any requirement.

>>>

>>> The GICv3 ITS driver is reworked to avoid executing preemptible code in

>>> non-preemptible context. This can be achieved by preparing the MSI

>>> maping when allocating the MSI interrupt.

>> mapping

>>>

>>> Signed-off-by: Julien Grall <julien.grall@arm.com>

>>>

>>> ---

>>>      Changes in v2:

>>>          - Rework the commit message to use imperative mood

>>> ---

>>>   drivers/irqchip/irq-gic-v3-its.c | 5 ++++-

>>>   1 file changed, 4 insertions(+), 1 deletion(-)

>>>

>>> diff --git a/drivers/irqchip/irq-gic-v3-its.c b/drivers/irqchip/irq-gic-v3-its.c

>>> index 7577755bdcf4..12ddbcfe1b1e 100644

>>> --- a/drivers/irqchip/irq-gic-v3-its.c

>>> +++ b/drivers/irqchip/irq-gic-v3-its.c

>>> @@ -1179,7 +1179,7 @@ static void its_irq_compose_msi_msg(struct irq_data *d, struct msi_msg *msg)

>>>   	msg->address_hi		= upper_32_bits(addr);

>>>   	msg->data		= its_get_event_id(d);

>>>   

>>> -	iommu_dma_map_msi_msg(d->irq, msg);

>>> +	iommu_dma_compose_msi_msg(irq_data_get_msi_desc(d), msg);

>>>   }

>>>   

>>>   static int its_irq_set_irqchip_state(struct irq_data *d,

>>> @@ -2566,6 +2566,7 @@ static int its_irq_domain_alloc(struct irq_domain *domain, unsigned int virq,

>>>   {

>>>   	msi_alloc_info_t *info = args;

>>>   	struct its_device *its_dev = info->scratchpad[0].ptr;

>>> +	struct its_node *its = its_dev->its;

>>>   	irq_hw_number_t hwirq;

>>>   	int err;

>>>   	int i;

>>> @@ -2574,6 +2575,8 @@ static int its_irq_domain_alloc(struct irq_domain *domain, unsigned int virq,

>>>   	if (err)

>>>   		return err;

>>>   

>>> +	err = iommu_dma_prepare_msi(info->desc, its->get_msi_base(its_dev));

>> Test err as in gicv2m driver?

> 

> Hmmm yes. Marc, do you want me to respin the patch?


Sure, feel free to if you can. But what I really need is an Ack from
Jorg on the first few patches.

Thanks,

	M.
-- 
Jazz is not dead. It just smells funny...