[RFC PATCH 0/3] Introducing I915_FORMAT_MOD_4_TILED_XE2_CCS Modifier for Xe2

[Juha-Pekka Heikkila]

These patches introduce I915_FORMAT_MOD_4_TILED_XE2_CCS modifier, which,
from the kernel's perspective, behaves similarly to `I915_FORMAT_MOD_4_TILED`.
This new modifier is primarily intended for user space to effectively monitor
compression status, especially when dealing with a mix of compressed and
uncompressed buffers.

The addition of this modifier facilitates user space in managing compression
status, particularly when utilizing both compressed and uncompressed buffers
concurrently. To leverage compression for these buffers, user space
applications must configure the appropriate Page Attribute Table (PAT) index.
Display engine will treat all Tile4 as if it were compressed under all
circumstances on Xe2 architecture.

Notably, this patch series omits support for X-tiled CCS and linear CCS
for Xe2, neither of which is supported by display engine. X-tiled CCS
offers stateless compression making it less likely to be extensively
utilized. Linear CCS does possess state, but currently lacks expected users.

These patches aim to enhance the flexibility and efficiency of handling
compressed and uncompressed buffers in Xe driver, particularly
catering to the specific requirements of the Xe2 architecture.

Juha-Pekka Heikkila (3):
  drm/fourcc: define Intel Xe2 related tile4 ccs modifier
  drm/xe/display: allow creation of case I915_FORMAT_MOD_4_TILED_XE2_CCS
    type framebuffer
  drm/i915/display: allow creation of case
    I915_FORMAT_MOD_4_TILED_XE2_CCS type framebuffer

 drivers/gpu/drm/i915/display/intel_display.c       |  1 +
 drivers/gpu/drm/i915/display/intel_fb.c            | 10 ++++++++++
 drivers/gpu/drm/i915/display/skl_universal_plane.c |  4 +++-
 drivers/gpu/drm/xe/display/xe_plane_initial.c      |  1 +
 include/uapi/drm/drm_fourcc.h                      | 12 ++++++++++++
 5 files changed, 27 insertions(+), 1 deletion(-)

-- 
2.43.2