drm/i915/ttm: pass along the I915_BO_ALLOC_CONTIGUOUS

Currently we just ignore the I915_BO_ALLOC_CONTIGUOUS flag, which is
fine since everything is already contiguous with the ttm range manager.
However in the next patch we want to switch over to the ttm buddy
manager, where allocations are by default not contiguous.

v2(Thomas):
    - Forward ALLOC_CONTIG for all regions
Signed-off-by: Matthew Auld <matthew.auld@intel.com>
Cc: Thomas Hellström <thomas.hellstrom@linux.intel.com>
Reviewed-by: Thomas Hellström <thomas.hellstrom@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20210616152501.394518-4-matthew.auld@intel.com

drivers/gpu/drm/i915/gem/i915_gem_ttm.c

@@ -79,10 +79,14 @@ i915_ttm_select_tt_caching(const struct drm_i915_gem_object *obj)
 
 static void
 i915_ttm_place_from_region(const struct intel_memory_region *mr,
-			   struct ttm_place *place)
+			   struct ttm_place *place,
+			   unsigned int flags)
 {
 	memset(place, 0, sizeof(*place));
 	place->mem_type = intel_region_to_ttm_type(mr);
+
+	if (flags & I915_BO_ALLOC_CONTIGUOUS)
+		place->flags = TTM_PL_FLAG_CONTIGUOUS;
 }
 
 static void
@@ -92,16 +96,17 @@ i915_ttm_placement_from_obj(const struct drm_i915_gem_object *obj,
 			    struct ttm_placement *placement)
 {
 	unsigned int num_allowed = obj->mm.n_placements;
+	unsigned int flags = obj->flags;
 	unsigned int i;
 
 	placement->num_placement = 1;
 	i915_ttm_place_from_region(num_allowed ? obj->mm.placements[0] :
-				   obj->mm.region, requested);
+				   obj->mm.region, requested, flags);
 
 	/* Cache this on object? */
 	placement->num_busy_placement = num_allowed;
 	for (i = 0; i < placement->num_busy_placement; ++i)
-		i915_ttm_place_from_region(obj->mm.placements[i], busy + i);
+		i915_ttm_place_from_region(obj->mm.placements[i], busy + i, flags);
 
 	if (num_allowed == 0) {
 		*busy = *requested;