[igt-dev] [PATCH v2 48/64] drm-uapi/xe: Document the memory_region bitmask

[Francois Dugast]

Align with kernel commit ("drm/xe/uapi: Document the memory_region bitmask")

Signed-off-by: Francois Dugast <francois.dugast at intel.com>
---
 include/drm-uapi/xe_drm.h | 23 ++++++++++++++++++-----
 1 file changed, 18 insertions(+), 5 deletions(-)

diff --git a/include/drm-uapi/xe_drm.h b/include/drm-uapi/xe_drm.h
index aecd2d736..399da4535 100644
--- a/include/drm-uapi/xe_drm.h
+++ b/include/drm-uapi/xe_drm.h
@@ -231,6 +231,10 @@ struct drm_xe_query_engine_info {
 	/**
 	 * @near_mem_regions: Bit mask of instances from
 	 * drm_xe_query_mem_regions that is near this engine.
+	 * Each index in this mask refers directly to the struct
+	 * drm_xe_query_mem_regions' instance, no assumptions should
+	 * be made about order. The type of each region is described
+	 * by struct drm_xe_query_mem_regions' mem_class.
 	 */
 	__u64 near_mem_regions;
 	/**
@@ -239,6 +243,10 @@ struct drm_xe_query_engine_info {
 	 * In general, it has extra indirections when compared to the
 	 * @near_mem_regions. For a discrete device this could mean system
 	 * memory and memory living in a different Tile.
+	 * Each index in this mask refers directly to the struct
+	 * drm_xe_query_mem_regions' instance, no assumptions should
+	 * be made about order. The type of each region is described
+	 * by struct drm_xe_query_mem_regions' mem_class.
 	 */
 	__u64 far_mem_regions;
 
@@ -272,10 +280,9 @@ struct drm_xe_query_mem_region {
 	 */
 	__u16 mem_class;
 	/**
-	 * @instance: The instance for this region.
-	 *
-	 * The @mem_class and @instance taken together will always give
-	 * a unique pair.
+	 * @instance: The unique ID for this region, which serves as the
+	 * index in the placement bitmask used as argument for
+	 * &DRM_IOCTL_XE_GEM_CREATE
 	 */
 	__u16 instance;
 	/** @pad: MBZ */
@@ -692,7 +699,13 @@ struct drm_xe_gem_create {
 	 */
 	__u64 size;
 
-	/** @placement: A mask of memory instances of where GEM can be placed. */
+	/**
+	 * @placement: A mask of memory instances of where GEM can be placed.
+	 * Each index in this mask refers directly to the struct
+	 * drm_xe_query_mem_regions' instance, no assumptions should
+	 * be made about order. The type of each region is described
+	 * by struct drm_xe_query_mem_regions' mem_class.
+	 */
 	__u32 placement;
 
 #define DRM_XE_GEM_CREATE_FLAG_DEFER_BACKING		(1 << 0)
-- 
2.34.1