[igt-dev] [PATCH i-g-t 1/2] lib/i915/gem_engine_topology: list engines specific to gt

[Kamil Konieczny]

Hi,

On 2023-04-05 at 12:28:31 +0530, Vikas Srivastava wrote:
> From: Riana Tauro <riana.tauro at intel.com>
> 
> Add a function that returns all engines belonging to a gt
> Currently the function is specific to MTL and returns gt id
> based on engine
> 
> Signed-off-by: Riana Tauro <riana.tauro at intel.com>
> Cc: Ashutosh Dixit <ashutosh.dixit at intel.com>
> Signed-off-by: Vikas Srivastava <vikas.srivastava at intel.com>
> ---
>  lib/i915/gem_engine_topology.c | 73 ++++++++++++++++++++++++++++++++++
>  lib/i915/gem_engine_topology.h |  6 +++
>  2 files changed, 79 insertions(+)
> 
> diff --git a/lib/i915/gem_engine_topology.c b/lib/i915/gem_engine_topology.c
> index ca3333c252..6c8929ec59 100644
> --- a/lib/i915/gem_engine_topology.c
> +++ b/lib/i915/gem_engine_topology.c
> @@ -350,6 +350,79 @@ struct intel_execution_engine2 gem_eb_flags_to_engine(unsigned int flags)
>  	return e2__;
>  }
>  
> +/*
> + * MTL has two GT's, one containing render/compute/copy and the other
> + * containing media engines. Return gt id based on engine.
> + */
> +static int
> +mtl_engine_to_gt_map(const struct i915_engine_class_instance *e)
> +{
> +	switch (e->engine_class) {
> +	case I915_ENGINE_CLASS_RENDER:
> +	case I915_ENGINE_CLASS_COMPUTE:
> +	case I915_ENGINE_CLASS_COPY:
> +		return 0;
> +	case I915_ENGINE_CLASS_VIDEO:
> +	case I915_ENGINE_CLASS_VIDEO_ENHANCE:
> +		return 1;
> +	default:
> +		igt_assert_f(0, "Unsupported engine class %d\n", e->engine_class);
> +	}
> +}
> +
> +static int gem_engine_to_gt_map(int i915, const struct i915_engine_class_instance *engine)
> +{
> +	igt_require(IS_METEORLAKE(intel_get_drm_devid(i915)));

This will make it work only for MTL so imho it needs
to be improved later and also keep in mind that this
should work for multi-gpu case, for example MTL with
Arc 750 card(s).

Reviewed-by: Kamil Konieczny <kamil.konieczny at linux.intel.com>

--
Kamil

> +	return mtl_engine_to_gt_map(engine);
> +}
> +
> +/**
> + * gem_list_engines:
> + * @i915: i915 drm file descriptor
> + * @gt_mask: gt mask
> + * @class_mask: engine class mask
> + * @out: returned engine count
> + *
> + * Returns: the list of all physical engines belonging to the gt.
> + * Caller must free memory after use
> + */
> +struct i915_engine_class_instance *
> +gem_list_engines(int i915,
> +		 uint32_t gt_mask,
> +		 uint32_t class_mask,
> +		 unsigned int *out)
> +{
> +	struct i915_engine_class_instance *engines;
> +	struct drm_i915_query_engine_info *info;
> +	const int size = 256 << 10; /* enough for 8 classes of 256 engines */
> +	unsigned int max = 0, count = 0;
> +
> +	info = calloc(1, size);
> +	igt_assert(!__gem_query_engines(i915, info, size));
> +
> +	max = info->num_engines;
> +	engines = (struct i915_engine_class_instance *)info;
> +	for (unsigned int i = 0; i < max; i++) {
> +		const struct i915_engine_class_instance *e =
> +			&info->engines[i].engine;
> +
> +		if (!((class_mask >> e->engine_class) & 1))
> +			continue;
> +		if (!((gt_mask >> gem_engine_to_gt_map(i915, e)) & 1))
> +			continue;
> +
> +		engines[count++] = *e;
> +	}
> +
> +	if (!count) {
> +		free(engines);
> +		engines = NULL;
> +	}
> +
> +	*out = count;
> +	return engines;
> +}
> +
>  bool gem_engine_is_equal(const struct intel_execution_engine2 *e1,
>  			 const struct intel_execution_engine2 *e2)
>  {
> diff --git a/lib/i915/gem_engine_topology.h b/lib/i915/gem_engine_topology.h
> index 987f2bf944..89642c3172 100644
> --- a/lib/i915/gem_engine_topology.h
> +++ b/lib/i915/gem_engine_topology.h
> @@ -61,6 +61,12 @@ intel_get_current_physical_engine(struct intel_engine_data *ed);
>  
>  void intel_next_engine(struct intel_engine_data *ed);
>  
> +struct i915_engine_class_instance *
> +gem_list_engines(int i915,
> +		 uint32_t gt_mask,
> +		 uint32_t class_mask,
> +		 unsigned int *count);
> +
>  bool gem_engine_is_equal(const struct intel_execution_engine2 *e1,
>  			 const struct intel_execution_engine2 *e2);
>  
> -- 
> 2.25.1
>