RE: [PATCH hyperv-next v5 10/11] ACPI: irq: Introduce acpi_get_gsi_dispatcher()

[Michael Kelley]

From: Roman Kisel <romank@xxxxxxxxxxxxxxxxxxx> Sent: Friday, March 7, 2025 2:03 PM
> 
> Using acpi_irq_create_hierarchy() in the cases where the code
> also handles OF leads to code duplication as the ACPI subsystem
> doesn't provide means to compute the IRQ domain parent whereas
> the OF does.
> 
> Introduce acpi_get_gsi_dispatcher() so that the drivers relying
> on both ACPI and OF may use irq_domain_create_hierarchy() in the
> common code paths.
> 
> No functional changes.
> 
> Signed-off-by: Roman Kisel <romank@xxxxxxxxxxxxxxxxxxx>
> ---
>  drivers/acpi/irq.c   | 14 ++++++++++++--
>  include/linux/acpi.h |  5 ++++-
>  2 files changed, 16 insertions(+), 3 deletions(-)
> 
> diff --git a/drivers/acpi/irq.c b/drivers/acpi/irq.c
> index 1687483ff319..6243db610137 100644
> --- a/drivers/acpi/irq.c
> +++ b/drivers/acpi/irq.c
> @@ -12,7 +12,7 @@
> 
>  enum acpi_irq_model_id acpi_irq_model;
> 
> -static struct fwnode_handle *(*acpi_get_gsi_domain_id)(u32 gsi);
> +static acpi_gsi_domain_disp_fn acpi_get_gsi_domain_id;
>  static u32 (*acpi_gsi_to_irq_fallback)(u32 gsi);
> 
>  /**
> @@ -307,12 +307,22 @@ EXPORT_SYMBOL_GPL(acpi_irq_get);
>   *	for a given GSI
>   */
>  void __init acpi_set_irq_model(enum acpi_irq_model_id model,
> -			       struct fwnode_handle *(*fn)(u32))
> +	acpi_gsi_domain_disp_fn fn)
>  {
>  	acpi_irq_model = model;
>  	acpi_get_gsi_domain_id = fn;
>  }
> 
> +/**
> + * acpi_get_gsi_dispatcher - Returns dispatcher function that
> + *                           computes the domain fwnode for a
> + *                           given GSI.
> + */
> +acpi_gsi_domain_disp_fn acpi_get_gsi_dispatcher(void)
> +{
> +	return acpi_get_gsi_domain_id;
> +}

This new function is needed by pci-hyperv.c. It will
need to be marked as EXPORT_SYMBOL_GPL since
pci-hyperv.c can be built as a module.

> +
>  /**
>   * acpi_set_gsi_to_irq_fallback - Register a GSI transfer
>   * callback to fallback to arch specified implementation.
> diff --git a/include/linux/acpi.h b/include/linux/acpi.h
> index 4e495b29c640..abc51288e867 100644
> --- a/include/linux/acpi.h
> +++ b/include/linux/acpi.h
> @@ -336,8 +336,11 @@ int acpi_register_gsi (struct device *dev, u32 gsi, int triggering, int
> polarity
>  int acpi_gsi_to_irq (u32 gsi, unsigned int *irq);
>  int acpi_isa_irq_to_gsi (unsigned isa_irq, u32 *gsi);
> 
> +typedef struct fwnode_handle *(*acpi_gsi_domain_disp_fn)(u32);
> +
>  void acpi_set_irq_model(enum acpi_irq_model_id model,
> -			struct fwnode_handle *(*)(u32));
> +	acpi_gsi_domain_disp_fn fn);
> +acpi_gsi_domain_disp_fn acpi_get_gsi_dispatcher(void);
>  void acpi_set_gsi_to_irq_fallback(u32 (*)(u32));
> 
>  struct irq_domain *acpi_irq_create_hierarchy(unsigned int flags,
> --
> 2.43.0
> 

I'm not at all expert in ACPI code and IRQ domains, but the changes
here look reasonable to me. Modulo adding the EXPORT_SYMBOL_GPL,

Reviewed-by: Michael Kelley <mhklinux@xxxxxxxxxxx>