diff mbox series

[v2,1/2] genirq: add an irq_create_mapping_affinity() function

Message ID 20201125111657.1141295-2-lvivier@redhat.com (mailing list archive)
State Superseded
Headers show
Series powerpc/pseries: fix MSI/X IRQ affinity on pseries | expand

Commit Message

Laurent Vivier Nov. 25, 2020, 11:16 a.m. UTC
This function adds an affinity parameter to irq_create_mapping().
This parameter is needed to pass it to irq_domain_alloc_descs().

irq_create_mapping() is a wrapper around irq_create_mapping_affinity()
to pass NULL for the affinity parameter.

No functional change.

Signed-off-by: Laurent Vivier <lvivier@redhat.com>
---
 include/linux/irqdomain.h | 12 ++++++++++--
 kernel/irq/irqdomain.c    | 13 ++++++++-----
 2 files changed, 18 insertions(+), 7 deletions(-)

Comments

Greg Kurz Nov. 25, 2020, 12:45 p.m. UTC | #1
On Wed, 25 Nov 2020 12:16:56 +0100
Laurent Vivier <lvivier@redhat.com> wrote:

> This function adds an affinity parameter to irq_create_mapping().
> This parameter is needed to pass it to irq_domain_alloc_descs().
> 
> irq_create_mapping() is a wrapper around irq_create_mapping_affinity()
> to pass NULL for the affinity parameter.
> 
> No functional change.
> 
> Signed-off-by: Laurent Vivier <lvivier@redhat.com>
> ---

Reviewed-by: Greg Kurz <groug@kaod.org>

>  include/linux/irqdomain.h | 12 ++++++++++--
>  kernel/irq/irqdomain.c    | 13 ++++++++-----
>  2 files changed, 18 insertions(+), 7 deletions(-)
> 
> diff --git a/include/linux/irqdomain.h b/include/linux/irqdomain.h
> index 71535e87109f..ea5a337e0f8b 100644
> --- a/include/linux/irqdomain.h
> +++ b/include/linux/irqdomain.h
> @@ -384,11 +384,19 @@ extern void irq_domain_associate_many(struct irq_domain *domain,
>  extern void irq_domain_disassociate(struct irq_domain *domain,
>  				    unsigned int irq);
>  
> -extern unsigned int irq_create_mapping(struct irq_domain *host,
> -				       irq_hw_number_t hwirq);
> +extern unsigned int irq_create_mapping_affinity(struct irq_domain *host,
> +				      irq_hw_number_t hwirq,
> +				      const struct irq_affinity_desc *affinity);
>  extern unsigned int irq_create_fwspec_mapping(struct irq_fwspec *fwspec);
>  extern void irq_dispose_mapping(unsigned int virq);
>  
> +static inline unsigned int irq_create_mapping(struct irq_domain *host,
> +					      irq_hw_number_t hwirq)
> +{
> +	return irq_create_mapping_affinity(host, hwirq, NULL);
> +}
> +
> +
>  /**
>   * irq_linear_revmap() - Find a linux irq from a hw irq number.
>   * @domain: domain owning this hardware interrupt
> diff --git a/kernel/irq/irqdomain.c b/kernel/irq/irqdomain.c
> index cf8b374b892d..e4ca69608f3b 100644
> --- a/kernel/irq/irqdomain.c
> +++ b/kernel/irq/irqdomain.c
> @@ -624,17 +624,19 @@ unsigned int irq_create_direct_mapping(struct irq_domain *domain)
>  EXPORT_SYMBOL_GPL(irq_create_direct_mapping);
>  
>  /**
> - * irq_create_mapping() - Map a hardware interrupt into linux irq space
> + * irq_create_mapping_affinity() - Map a hardware interrupt into linux irq space
>   * @domain: domain owning this hardware interrupt or NULL for default domain
>   * @hwirq: hardware irq number in that domain space
> + * @affinity: irq affinity
>   *
>   * Only one mapping per hardware interrupt is permitted. Returns a linux
>   * irq number.
>   * If the sense/trigger is to be specified, set_irq_type() should be called
>   * on the number returned from that call.
>   */
> -unsigned int irq_create_mapping(struct irq_domain *domain,
> -				irq_hw_number_t hwirq)
> +unsigned int irq_create_mapping_affinity(struct irq_domain *domain,
> +				       irq_hw_number_t hwirq,
> +				       const struct irq_affinity_desc *affinity)
>  {
>  	struct device_node *of_node;
>  	int virq;
> @@ -660,7 +662,8 @@ unsigned int irq_create_mapping(struct irq_domain *domain,
>  	}
>  
>  	/* Allocate a virtual interrupt number */
> -	virq = irq_domain_alloc_descs(-1, 1, hwirq, of_node_to_nid(of_node), NULL);
> +	virq = irq_domain_alloc_descs(-1, 1, hwirq, of_node_to_nid(of_node),
> +				      affinity);
>  	if (virq <= 0) {
>  		pr_debug("-> virq allocation failed\n");
>  		return 0;
> @@ -676,7 +679,7 @@ unsigned int irq_create_mapping(struct irq_domain *domain,
>  
>  	return virq;
>  }
> -EXPORT_SYMBOL_GPL(irq_create_mapping);
> +EXPORT_SYMBOL_GPL(irq_create_mapping_affinity);
>  
>  /**
>   * irq_create_strict_mappings() - Map a range of hw irqs to fixed linux irqs
Thomas Gleixner Nov. 25, 2020, 1:20 p.m. UTC | #2
Laurent,

On Wed, Nov 25 2020 at 12:16, Laurent Vivier wrote:

The proper subsystem prefix is: 'genirq/irqdomain:' and the first letter
after the colon wants to be uppercase.

> This function adds an affinity parameter to irq_create_mapping().
> This parameter is needed to pass it to irq_domain_alloc_descs().

A changelog has to explain the WHY. 'The parameter is needed' is not
really useful information.

Thanks,

        tglx
Laurent Vivier Nov. 25, 2020, 2:09 p.m. UTC | #3
On 25/11/2020 14:20, Thomas Gleixner wrote:
> Laurent,
> 
> On Wed, Nov 25 2020 at 12:16, Laurent Vivier wrote:
> 
> The proper subsystem prefix is: 'genirq/irqdomain:' and the first letter
> after the colon wants to be uppercase.

Ok.

>> This function adds an affinity parameter to irq_create_mapping().
>> This parameter is needed to pass it to irq_domain_alloc_descs().
> 
> A changelog has to explain the WHY. 'The parameter is needed' is not
> really useful information.
> 

The reason of this change is explained in PATCH 2.

I have two patches, one to change the interface with no functional change (PATCH 1) and
one to fix the problem (PATCH 2). Moreover they don't cover the same subsystems.

I can either:
- merge the two patches
- or make a reference in the changelog of PATCH 1 to PATCH 2
  (something like "(see folowing patch "powerpc/pseries: pass MSI affinity to
   irq_create_mapping()")")
- or copy some information from PATCH 2
  (something like "this parameter is needed by rtas_setup_msi_irqs() to pass the affinity
   to irq_domain_alloc_descs() to fix multiqueue affinity")

What do you prefer?

Thanks,
Laurent
Marc Zyngier Nov. 25, 2020, 2:54 p.m. UTC | #4
On 2020-11-25 14:09, Laurent Vivier wrote:
> On 25/11/2020 14:20, Thomas Gleixner wrote:
>> Laurent,
>> 
>> On Wed, Nov 25 2020 at 12:16, Laurent Vivier wrote:
>> 
>> The proper subsystem prefix is: 'genirq/irqdomain:' and the first 
>> letter
>> after the colon wants to be uppercase.
> 
> Ok.
> 
>>> This function adds an affinity parameter to irq_create_mapping().
>>> This parameter is needed to pass it to irq_domain_alloc_descs().
>> 
>> A changelog has to explain the WHY. 'The parameter is needed' is not
>> really useful information.
>> 
> 
> The reason of this change is explained in PATCH 2.
> 
> I have two patches, one to change the interface with no functional
> change (PATCH 1) and
> one to fix the problem (PATCH 2). Moreover they don't cover the same 
> subsystems.
> 
> I can either:
> - merge the two patches
> - or make a reference in the changelog of PATCH 1 to PATCH 2
>   (something like "(see folowing patch "powerpc/pseries: pass MSI 
> affinity to
>    irq_create_mapping()")")
> - or copy some information from PATCH 2
>   (something like "this parameter is needed by rtas_setup_msi_irqs()
> to pass the affinity
>    to irq_domain_alloc_descs() to fix multiqueue affinity")
> 
> What do you prefer?

How about something like this for the first patch:

"There is currently no way to convey the affinity of an interrupt
  via irq_create_mapping(), which creates issues for devices that
  expect that affinity to be managed by the kernel.

  In order to sort this out, rename irq_create_mapping() to
  irq_create_mapping_affinity() with an additional affinity parameter
  that can conveniently passed down to irq_domain_alloc_descs().

  irq_create_mapping() is then re-implemented as a wrapper around
  irq_create_mapping_affinity()."

Thanks,

         M.
Laurent Vivier Nov. 25, 2020, 3 p.m. UTC | #5
On 25/11/2020 15:54, Marc Zyngier wrote:
> On 2020-11-25 14:09, Laurent Vivier wrote:
>> On 25/11/2020 14:20, Thomas Gleixner wrote:
>>> Laurent,
>>>
>>> On Wed, Nov 25 2020 at 12:16, Laurent Vivier wrote:
>>>
>>> The proper subsystem prefix is: 'genirq/irqdomain:' and the first letter
>>> after the colon wants to be uppercase.
>>
>> Ok.
>>
>>>> This function adds an affinity parameter to irq_create_mapping().
>>>> This parameter is needed to pass it to irq_domain_alloc_descs().
>>>
>>> A changelog has to explain the WHY. 'The parameter is needed' is not
>>> really useful information.
>>>
>>
>> The reason of this change is explained in PATCH 2.
>>
>> I have two patches, one to change the interface with no functional
>> change (PATCH 1) and
>> one to fix the problem (PATCH 2). Moreover they don't cover the same subsystems.
>>
>> I can either:
>> - merge the two patches
>> - or make a reference in the changelog of PATCH 1 to PATCH 2
>>   (something like "(see folowing patch "powerpc/pseries: pass MSI affinity to
>>    irq_create_mapping()")")
>> - or copy some information from PATCH 2
>>   (something like "this parameter is needed by rtas_setup_msi_irqs()
>> to pass the affinity
>>    to irq_domain_alloc_descs() to fix multiqueue affinity")
>>
>> What do you prefer?
> 
> How about something like this for the first patch:
> 
> "There is currently no way to convey the affinity of an interrupt
>  via irq_create_mapping(), which creates issues for devices that
>  expect that affinity to be managed by the kernel.
> 
>  In order to sort this out, rename irq_create_mapping() to
>  irq_create_mapping_affinity() with an additional affinity parameter
>  that can conveniently passed down to irq_domain_alloc_descs().
> 
>  irq_create_mapping() is then re-implemented as a wrapper around
>  irq_create_mapping_affinity()."

It looks perfect. I update the changelog with that.

Thanks,
Laurent
diff mbox series

Patch

diff --git a/include/linux/irqdomain.h b/include/linux/irqdomain.h
index 71535e87109f..ea5a337e0f8b 100644
--- a/include/linux/irqdomain.h
+++ b/include/linux/irqdomain.h
@@ -384,11 +384,19 @@  extern void irq_domain_associate_many(struct irq_domain *domain,
 extern void irq_domain_disassociate(struct irq_domain *domain,
 				    unsigned int irq);
 
-extern unsigned int irq_create_mapping(struct irq_domain *host,
-				       irq_hw_number_t hwirq);
+extern unsigned int irq_create_mapping_affinity(struct irq_domain *host,
+				      irq_hw_number_t hwirq,
+				      const struct irq_affinity_desc *affinity);
 extern unsigned int irq_create_fwspec_mapping(struct irq_fwspec *fwspec);
 extern void irq_dispose_mapping(unsigned int virq);
 
+static inline unsigned int irq_create_mapping(struct irq_domain *host,
+					      irq_hw_number_t hwirq)
+{
+	return irq_create_mapping_affinity(host, hwirq, NULL);
+}
+
+
 /**
  * irq_linear_revmap() - Find a linux irq from a hw irq number.
  * @domain: domain owning this hardware interrupt
diff --git a/kernel/irq/irqdomain.c b/kernel/irq/irqdomain.c
index cf8b374b892d..e4ca69608f3b 100644
--- a/kernel/irq/irqdomain.c
+++ b/kernel/irq/irqdomain.c
@@ -624,17 +624,19 @@  unsigned int irq_create_direct_mapping(struct irq_domain *domain)
 EXPORT_SYMBOL_GPL(irq_create_direct_mapping);
 
 /**
- * irq_create_mapping() - Map a hardware interrupt into linux irq space
+ * irq_create_mapping_affinity() - Map a hardware interrupt into linux irq space
  * @domain: domain owning this hardware interrupt or NULL for default domain
  * @hwirq: hardware irq number in that domain space
+ * @affinity: irq affinity
  *
  * Only one mapping per hardware interrupt is permitted. Returns a linux
  * irq number.
  * If the sense/trigger is to be specified, set_irq_type() should be called
  * on the number returned from that call.
  */
-unsigned int irq_create_mapping(struct irq_domain *domain,
-				irq_hw_number_t hwirq)
+unsigned int irq_create_mapping_affinity(struct irq_domain *domain,
+				       irq_hw_number_t hwirq,
+				       const struct irq_affinity_desc *affinity)
 {
 	struct device_node *of_node;
 	int virq;
@@ -660,7 +662,8 @@  unsigned int irq_create_mapping(struct irq_domain *domain,
 	}
 
 	/* Allocate a virtual interrupt number */
-	virq = irq_domain_alloc_descs(-1, 1, hwirq, of_node_to_nid(of_node), NULL);
+	virq = irq_domain_alloc_descs(-1, 1, hwirq, of_node_to_nid(of_node),
+				      affinity);
 	if (virq <= 0) {
 		pr_debug("-> virq allocation failed\n");
 		return 0;
@@ -676,7 +679,7 @@  unsigned int irq_create_mapping(struct irq_domain *domain,
 
 	return virq;
 }
-EXPORT_SYMBOL_GPL(irq_create_mapping);
+EXPORT_SYMBOL_GPL(irq_create_mapping_affinity);
 
 /**
  * irq_create_strict_mappings() - Map a range of hw irqs to fixed linux irqs