drm/xe: add page size allocation control state to xe_device

Introduce xe_page_size_alloc_ctrl_mode and add page_size_alloc_ctrl
state to struct xe_device along with mutex lock.

The new control supports forcing user BO allocations to 2M pages,
forcing them to 1G pages, or using a mixed round-robin mode across
4K, 64K, 2M, and 1G page sizes. Track the current mixed-mode index
in xe_device so allocation policy can be applied consistently.

v2
- make cur_index to atomic as update need in later patch to
  avoid race/concurency (sashiko)
v3
- reworded comments
- protect mode/index updates with a mutex for proper concurrency handling

v4(sashiko)
- move xe_debug_page_size_alloc_ctrl_init() before drm_dev_register(),
  so mutex and control states are initialized
  before any userspace visibility

v5(Himal)
- Guard all the debug page size policy code under CONFIG
- Squash Kconfig patch to have Kconfig entry for DEBUG_PAGE_SIZE
- Add inline to check debug page size support and exact mode
  configured if it is supported.

v6 (fix CI build)

v8 (Himal)
- use drmm_mutex_init to avoid leak with mutex_init
- call xe_debug_page_size_alloc_ctrl_init unconditionally
- Add missed mixed mode check on xe_debug_page_size_mode_not_none check
- Add xe_debug_page_size_mode_is_mixed() function

v9
- make xe_debug_page_size_alloc_ctrl_init() return int
- fail probe if drmm_mutex_init() for page_size_alloc_ctrl.lock fails

Signed-off-by: Nareshkumar Gollakoti <naresh.kumar.g@intel.com>
Reviewed-by: Himal Prasad Ghimiray <himal.prasad.ghimiray@intel.com>
Link: https://patch.msgid.link/20260729121843.1255891-2-naresh.kumar.g@intel.com
Signed-off-by: Himal Prasad Ghimiray <himal.prasad.ghimiray@intel.com>

0 files changed, 0 insertions, 0 deletions