Re: [Intel-gfx] [PATCH 5/6] drm/i915: Add stable memory region names

["Iddamsetty, Aravind" <aravind.iddamsetty@intel.com>]

On 22-09-2023 19:16, Tvrtko Ursulin wrote:
> From: Tvrtko Ursulin <tvrtko.ursulin@intel.com>
> 
> At the moment memory region names are a bit too varied and too
> inconsistent to be used for ABI purposes, like for upcoming fdinfo
> memory stats.
> 
> System memory can be either system or system-ttm. Local memory has the
> instance number appended, others do not. Not only incosistent but thi
> kind of implementation detail is uninteresting for intended users of
> fdinfo memory stats.
> 
> Add a stable name always formed as $type$instance. Could have chosen a
> different stable scheme, but I think any consistent and stable scheme
> should do just fine.
> 
> Signed-off-by: Tvrtko Ursulin <tvrtko.ursulin@intel.com>
> ---
>  drivers/gpu/drm/i915/intel_memory_region.c | 19 +++++++++++++++++++
>  drivers/gpu/drm/i915/intel_memory_region.h |  1 +
>  2 files changed, 20 insertions(+)
> 
> diff --git a/drivers/gpu/drm/i915/intel_memory_region.c b/drivers/gpu/drm/i915/intel_memory_region.c
> index 3d1fdea9811d..60a03340bbd4 100644
> --- a/drivers/gpu/drm/i915/intel_memory_region.c
> +++ b/drivers/gpu/drm/i915/intel_memory_region.c
> @@ -216,6 +216,22 @@ static int intel_memory_region_memtest(struct intel_memory_region *mem,
>  	return err;
>  }
>  
> +static const char *region_type_str(u16 type)
> +{
> +	switch (type) {
> +	case INTEL_MEMORY_SYSTEM:
> +		return "system";
> +	case INTEL_MEMORY_LOCAL:
> +		return "local";
> +	case INTEL_MEMORY_STOLEN_LOCAL:
> +		return "stolen-local";
> +	case INTEL_MEMORY_STOLEN_SYSTEM:
> +		return "stolen-system";
> +	default:
> +		return "unknown";
> +	}
> +}
> +
>  struct intel_memory_region *
>  intel_memory_region_create(struct drm_i915_private *i915,
>  			   resource_size_t start,
> @@ -244,6 +260,9 @@ intel_memory_region_create(struct drm_i915_private *i915,
>  	mem->type = type;
>  	mem->instance = instance;
>  
> +	snprintf(mem->uabi_name, sizeof(mem->uabi_name), "%s%u",
> +		 region_type_str(type), instance);
> +
>  	mutex_init(&mem->objects.lock);
>  	INIT_LIST_HEAD(&mem->objects.list);
>  
> diff --git a/drivers/gpu/drm/i915/intel_memory_region.h b/drivers/gpu/drm/i915/intel_memory_region.h
> index 2953ed5c3248..9ba36454e51b 100644
> --- a/drivers/gpu/drm/i915/intel_memory_region.h
> +++ b/drivers/gpu/drm/i915/intel_memory_region.h
> @@ -80,6 +80,7 @@ struct intel_memory_region {
>  	u16 instance;
>  	enum intel_region_id id;
>  	char name[16];
> +	char uabi_name[16];

Just a thought instead of creating a new field, can't we derive this
with name and instance?

Thanks,
Aravind.
>  	bool private; /* not for userspace */
>  
>  	struct {