• Lionel Landwerlin's avatar
    drm/i915: expose rcs topology through query uAPI · c822e059
    Lionel Landwerlin authored
    With the introduction of asymmetric slices in CNL, we cannot rely on
    the previous SUBSLICE_MASK getparam to tell userspace what subslices
    are available. Here we introduce a more detailed way of querying the
    Gen's GPU topology that doesn't aggregate numbers.
    
    This is essential for monitoring parts of the GPU with the OA unit,
    because counters need to be normalized to the number of
    EUs/subslices/slices. The current aggregated numbers like EU_TOTAL do
    not gives us sufficient information.
    
    The Mesa series making use of this API is :
    
        https://patchwork.freedesktop.org/series/38795/
    
    As a bonus we can draw representations of the GPU :
    
        https://imgur.com/a/vuqpa
    
    v2: Rename uapi struct s/_mask/_info/ (Tvrtko)
        Report max_slice/subslice/eus_per_subslice rather than strides (Tvrtko)
        Add uapi macros to read data from *_info structs (Tvrtko)
    
    v3: Use !!(v & DRM_I915_BIT()) for uapi macros instead of custom shifts (Tvrtko)
    
    v4: factorize query item writting (Tvrtko)
        tweak uapi struct/define names (Tvrtko)
    
    v5: Replace ALIGN() macro (Chris)
    
    v6: Updated uapi comments (Tvrtko)
        Moved flags != 0 checks into vfuncs (Tvrtko)
    
    v7: Use access_ok() before copying anything, to avoid overflows (Chris)
        Switch BUG_ON() to GEM_WARN_ON() (Tvrtko)
    
    v8: Tweak uapi comments style to match the coding style (Lionel)
    
    v9: Fix error in comment about computation of enabled subslice (Tvrtko)
    
    v10: Fix/update comments in uAPI (Sagar)
    
    v11: Drop drm_i915_query_(slice|subslice|eu)_info in favor of a single
         drm_i915_query_topology_info (Joonas)
    
    v12: Add subslice_stride/eu_stride in drm_i915_query_topology_info (Joonas)
    
    v13: Fix comment in uAPI (Joonas)
    Signed-off-by: default avatarLionel Landwerlin <lionel.g.landwerlin@intel.com>
    Acked-by: default avatarChris Wilson <chris@chris-wilson.co.uk>
    Reviewed-by: default avatarJoonas Lahtinen <joonas.lahtinen@linux.intel.com>
    Link: https://patchwork.freedesktop.org/patch/msgid/20180306122857.27317-7-lionel.g.landwerlin@intel.com
    c822e059
i915_drm.h 54.8 KB