drm/i915/gem: Add extra pages in ttm_tt for ccs data

drm/i915/gem: Add extra pages in ttm_tt for ccs data

On Xe-HP and later devices, dedicated compression control state (CCS)
stored in local memory is used for each surface, to support the
3D and media compression formats.

The memory required for the CCS of the entire local memory is 1/256 of
the local memory size. So before the kernel boot, the required memory
is reserved for the CCS data and a secure register will be programmed
with the CCS base address

So when an object is allocated in local memory, dont need to explicitly
allocate the space for ccs data. But when the obj is evicted into the
smem, to hold the compression related data along with the obj extra space
is needed in smem. i.e obj_size + (obj_size/256).

Hence when a smem pages are allocated for an obj with lmem placement
possibility we create with the extra pages required for the ccs data for
the obj size.

v2:
  Used imperative wording [Thomas]
v3:
  Inflate the pages only when obj's placement is lmem only
v4:
  GEM_BUG_ON if the ttm->num_pages > obj page size [Thomas]

Signed-off-by: Ramalingam C <ramalingam.c@intel.com>
cc: Christian Koenig <christian.koenig@amd.com>
cc: Hellstrom Thomas <thomas.hellstrom@intel.com>
Reviewed-by: Thomas Hellstrom <thomas.hellstrom@linux.intel.com>
Reviewed-by: Nirmoy Das <nirmoy.das@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20220405150840.29351-9-ramalingam.c@intel.com