Render Decompression is supported with Y-Tiled main surface. The CCS is
linear and has 4 bits of data for each main surface cache line pair, a
ratio of 1:256. Additional Clear Color information is passed from the
user-space through an offset in the GEM BO. Add a new modifier to identify
and parse new Clear Color information and extend Gen12 render decompression
functionality to the newly added modifier.

v2: Fix has_alpha flag for modifiers, omit CC modifier during initial
    plane config(Matt). Fix Lookup error.
v3: Fix the panic while running kms_cube
v4: Add alignment check and reuse the comments for ge12_ccs_formats(Matt)
v5: Fix typos and wrap comments(Matt)
v6:
- Use format block descriptors to get the subsampling calculations for
  the CCS surface right.
- Use helpers to convert between main and CCS surfaces.
- Prevent coordinate checks for the CC surface.
- Simplify reading CC value from surface map, add description of CC val
  layout.
- Remove redundant ccval variable from skl_program_plane().
v7:
- Move the CC value readout after syncing against any GPU write on the
  FB obj (Nanley, Chris)
- Make sure the CC value readout works on platforms w/o struct pages
  (dGFX) and other non-coherent platforms wrt. CPU reads (none atm).
  (Chris)
v8:
- Rebase on the function param order change of
  i915_gem_object_read_from_page().
- Clarify code comment on the clear color value format and the required
  FB obj pinning/syncing by the caller.
- Remove redundant variables in
  intel_atomic_prepare_plane_clear_colors().
v9:
- Fix s/sizeof(&ccval)/sizeof(ccval)/ typo.

Cc: Dhinakaran Pandiyan <dhinakaran.pandiyan@intel.com>
Cc: Ville Syrjala <ville.syrjala@intel.com>
Cc: Shashank Sharma <shashank.sharma@intel.com>
Cc: Rafael Antognolli <rafael.antognolli@intel.com>
Cc: Nanley G Chery <nanley.g.chery@intel.com>
Cc: Chris Wilson <chris@chris-wilson.co.uk>
Reviewed-by: Matt Roper <matthew.d.roper@intel.com>
Signed-off-by: Radhakrishna Sripada <radhakrishna.sripada@intel.com>
Signed-off-by: Imre Deak <imre.deak@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20210115213952.1040398-1-imre.deak@intel.com