[PATCH v4 2/8] drm/xe: add Kconfig option for debug page-size allocation control

[Nareshkumar Gollakoti <naresh.kumar.g@intel.com>]

Add a Kconfig option to enable the debugfs interface used to control user
BO page-size allocation policy for validation and development.

When enabled, the driver exposes a debugfs knob that can force 2M mode,
force 1G mode, or select mixed round-robin page-size allocation behavior
on platforms that support multiple page sizes.

This option is intended for debug/testing only and does not provide a
stable userspace interface.

v4
- remove default n and refactor help and description

Signed-off-by: Nareshkumar Gollakoti <naresh.kumar.g@intel.com>
---
 drivers/gpu/drm/xe/Kconfig.debug | 16 ++++++++++++++++
 1 file changed, 16 insertions(+)

diff --git a/drivers/gpu/drm/xe/Kconfig.debug b/drivers/gpu/drm/xe/Kconfig.debug
index 01227c77f6d7..79118d9efd93 100644
--- a/drivers/gpu/drm/xe/Kconfig.debug
+++ b/drivers/gpu/drm/xe/Kconfig.debug
@@ -86,6 +86,22 @@ config DRM_XE_KUNIT_TEST
 
 	  If in doubt, say "N".
 
+config DRM_XE_DEBUG_PAGE_SIZE
+	bool "Enable debug control for user BO page-size allocation"
+	depends on DRM_XE_DEBUG && DEBUG_FS
+	help
+	  Expose a debugfs knob to override user BO page-size allocation
+	  handling for validation and debug. Supported modes include forced
+	  2M, forced 1G, and a mixed mode that exercises 4K, 64K, 2M, and
+	  1G page-size paths on platforms that support them.
+
+	  This is an unstable debugfs interface intended for development and
+	  validation only. Its layout, contents, and existence may change or
+	  be removed at any time with no regression warranty.
+
+	  Recommended for driver developers only.
+	  If in doubt, say "N".
+
 config DRM_XE_DEBUG_GUC
         bool "Enable extra GuC related debug options"
         depends on DRM_XE_DEBUG
-- 
2.43.0