Looks good to me, series is:
Reviewed-by: Francisco Jerez <curroje...@riseup.net>
Matt Roper <matthew.d.ro...@intel.com> writes:
> This structure has a great comment describing the fields, but it's not
> currently in kerneldoc form and does not show up in the generated
> documentation. Let's fix that and also clarify the description of what
> "subslice" refers to on gen12 platforms and beyond and that "slice" is
> no longer meaningful on Xe_HP and beyond.
>
> Signed-off-by: Matt Roper <matthew.d.ro...@intel.com>
> ---
> include/uapi/drm/i915_drm.h | 110 +++++++++++++++++++++++++-----------
> 1 file changed, 78 insertions(+), 32 deletions(-)
>
> diff --git a/include/uapi/drm/i915_drm.h b/include/uapi/drm/i915_drm.h
> index 9ab021c4d632..73e1c6180ddb 100644
> --- a/include/uapi/drm/i915_drm.h
> +++ b/include/uapi/drm/i915_drm.h
> @@ -2775,66 +2775,112 @@ struct drm_i915_query {
> __u64 items_ptr;
> };
>
> -/*
> - * Data written by the kernel with query DRM_I915_QUERY_TOPOLOGY_INFO :
> - *
> - * data: contains the 3 pieces of information :
> - *
> - * - the slice mask with one bit per slice telling whether a slice is
> - * available. The availability of slice X can be queried with the following
> - * formula :
> - *
> - * (data[X / 8] >> (X % 8)) & 1
> - *
> - * - the subslice mask for each slice with one bit per subslice telling
> - * whether a subslice is available. Gen12 has dual-subslices, which are
> - * similar to two gen11 subslices. For gen12, this array represents dual-
> - * subslices. The availability of subslice Y in slice X can be queried
> - * with the following formula :
> - *
> - * (data[subslice_offset +
> - * X * subslice_stride +
> - * Y / 8] >> (Y % 8)) & 1
> - *
> - * - the EU mask for each subslice in each slice with one bit per EU telling
> - * whether an EU is available. The availability of EU Z in subslice Y in
> - * slice X can be queried with the following formula :
> +/**
> + * struct drm_i915_query_topology_info
> *
> - * (data[eu_offset +
> - * (X * max_subslices + Y) * eu_stride +
> - * Z / 8] >> (Z % 8)) & 1
> + * Describes slice/subslice/EU information queried by
> + * %DRM_I915_QUERY_TOPOLOGY_INFO
> */
> struct drm_i915_query_topology_info {
> - /*
> + /**
> + * @flags:
> + *
> * Unused for now. Must be cleared to zero.
> */
> __u16 flags;
>
> + /**
> + * @max_slices:
> + *
> + * The number of bits used to express the slice mask.
> + */
> __u16 max_slices;
> +
> + /**
> + * @max_subslices:
> + *
> + * The number of bits used to express the subslice mask.
> + */
> __u16 max_subslices;
> +
> + /**
> + * @max_eus_per_subslice:
> + *
> + * The number of bits in the EU mask that correspond to a single
> + * subslice's EUs.
> + */
> __u16 max_eus_per_subslice;
>
> - /*
> + /**
> + * @subslice_offset:
> + *
> * Offset in data[] at which the subslice masks are stored.
> */
> __u16 subslice_offset;
>
> - /*
> + /**
> + * @subslice_stride:
> + *
> * Stride at which each of the subslice masks for each slice are
> * stored.
> */
> __u16 subslice_stride;
>
> - /*
> + /**
> + * @eu_offset:
> + *
> * Offset in data[] at which the EU masks are stored.
> */
> __u16 eu_offset;
>
> - /*
> + /**
> + * @eu_stride:
> + *
> * Stride at which each of the EU masks for each subslice are stored.
> */
> __u16 eu_stride;
>
> + /**
> + * @data:
> + *
> + * Contains 3 pieces of information :
> + *
> + * - The slice mask with one bit per slice telling whether a slice is
> + * available. The availability of slice X can be queried with the
> + * following formula :
> + *
> + * .. code:: c
> + *
> + * (data[X / 8] >> (X % 8)) & 1
> + *
> + * Starting with Xe_HP platforms, Intel hardware no longer has
> + * traditional slices so i915 will always report a single slice
> + * (hardcoded slicemask = 0x1) which contains all of the platform's
> + * subslices. I.e., the mask here does not reflect any of the newer
> + * hardware concepts such as "gslices" or "cslices" since userspace
> + * is capable of inferring those from the subslice mask.
> + *
> + * - The subslice mask for each slice with one bit per subslice telling
> + * whether a subslice is available. Starting with Gen12 we use the
> + * term "subslice" to refer to what the hardware documentation
> + * describes as a "dual-subslices." The availability of subslice Y
> + * in slice X can be queried with the following formula :
> + *
> + * .. code:: c
> + *
> + * (data[subslice_offset + X * subslice_stride + Y / 8] >> (Y %
> 8)) & 1
> + *
> + * - The EU mask for each subslice in each slice, with one bit per EU
> + * telling whether an EU is available. The availability of EU Z in
> + * subslice Y in slice X can be queried with the following formula :
> + *
> + * .. code:: c
> + *
> + * (data[eu_offset +
> + * (X * max_subslices + Y) * eu_stride +
> + * Z / 8
> + * ] >> (Z % 8)) & 1
> + */
> __u8 data[];
> };
>
> --
> 2.34.1
