Re: [PATCH 10/13] drm/xe/memirq: Introduce helper to calculate status vector offset

["Levi, Ilia" <ilia.levi@intel.com>]

On 4/28/2026 5:27 PM, Michal Wajdeczko wrote:
> We already have XE_MEMIRQ_STATUS_OFFSET() macro, but it expects
> that instance parameter will separately prepared based on the
> MSI-X status. Add memirq_status_vector_offset() helper function
> that will take care of this and by using engine specific offset,
> return an offset to the engine's status vector bytes.
>
> Signed-off-by: Michal Wajdeczko <michal.wajdeczko@intel.com>

NIT: same as in previous patch regarding commit message.

> ---
>  drivers/gpu/drm/xe/xe_memirq.c | 18 +++++++++++++++---
>  1 file changed, 15 insertions(+), 3 deletions(-)
>
> diff --git a/drivers/gpu/drm/xe/xe_memirq.c b/drivers/gpu/drm/xe/xe_memirq.c
> index 113b792d373e..f5e139f4525b 100644
> --- a/drivers/gpu/drm/xe/xe_memirq.c
> +++ b/drivers/gpu/drm/xe/xe_memirq.c
> @@ -289,13 +289,25 @@ u32 xe_memirq_source_ptr(struct xe_memirq *memirq, struct xe_hw_engine *hwe)
>  	return __memirq_source_page(memirq, hwe->instance);
>  }
>  
> +/* Return: offset to the status vector used by the given @source's nth @instance */


The semantics of source & instance become somewhat complex. Or rather they already were, but
adding the term "source" makes it more pronounced. Perhaps we should consider modifying the addressing
scheme to (irq_page, irq_offset) and set hwe->irq_page in hw_engine_init_early(). 
This will alleviate the need of overriding the instance in those helper functions. 

For example for BCS2 engine we'll configure:
if (MSI-x)
    irq_page = 2, irq_offset = ilog2(INTR_BCS(0))
else
    irq_page = 0, irq_offset = ilog2(INTR_BCS(2))


- Ilia

> +static u32 memirq_status_vector_offset(struct xe_memirq *memirq, u16 source, u16 instance)
> +{
> +	memirq_assert(memirq, instance <= XE_HW_ENGINE_MAX_INSTANCE);
> +
> +	instance = hw_reports_to_instance_zero(memirq) ? instance : 0;
> +	return XE_MEMIRQ_STATUS_OFFSET(instance) + source * SZ_16;
> +}
> +
> +static u32 memirq_status_page_offset(struct xe_memirq *memirq, u16 instance)
> +{
> +	return memirq_status_vector_offset(memirq, 0, instance);
> +}
> +
>  static u32 __memirq_status_page(struct xe_memirq *memirq, u16 instance)
>  {
> -	memirq_assert(memirq, instance <= XE_HW_ENGINE_MAX_INSTANCE);
>  	memirq_assert(memirq, memirq->bo);
>  
> -	instance = hw_reports_to_instance_zero(memirq) ? instance : 0;
> -	return xe_bo_ggtt_addr(memirq->bo) + XE_MEMIRQ_STATUS_OFFSET(instance);
> +	return xe_bo_ggtt_addr(memirq->bo) + memirq_status_page_offset(memirq, instance);
>  }
>  
>  /**