1 files changed, 41 insertions, 1 deletions
diff --git a/drivers/gpu/drm/i915/gem/i915_gem_lmem.c b/drivers/gpu/drm/i915/gem/i915_gem_lmem.c
index 2b8cd15de1d9..d539dffa1554 100644
--- a/drivers/gpu/drm/i915/gem/i915_gem_lmem.c
+++ b/drivers/gpu/drm/i915/gem/i915_gem_lmem.c
@@ -23,10 +23,50 @@ i915_gem_object_lmem_io_map(struct drm_i915_gem_object *obj,
 	return io_mapping_map_wc(&obj->mm.region->iomap, offset, size);
 }
 
+/**
+ * i915_gem_object_validates_to_lmem - Whether the object is resident in
+ * lmem when pages are present.
+ * @obj: The object to check.
+ *
+ * Migratable objects residency may change from under us if the object is
+ * not pinned or locked. This function is intended to be used to check whether
+ * the object can only reside in lmem when pages are present.
+ *
+ * Return: Whether the object is always resident in lmem when pages are
+ * present.
+ */
+bool i915_gem_object_validates_to_lmem(struct drm_i915_gem_object *obj)
+{
+	struct intel_memory_region *mr = READ_ONCE(obj->mm.region);
+
+	return !i915_gem_object_migratable(obj) &&
+		mr && (mr->type == INTEL_MEMORY_LOCAL ||
+		       mr->type == INTEL_MEMORY_STOLEN_LOCAL);
+}
+
+/**
+ * i915_gem_object_is_lmem - Whether the object is resident in
+ * lmem
+ * @obj: The object to check.
+ *
+ * Even if an object is allowed to migrate and change memory region,
+ * this function checks whether it will always be present in lmem when
+ * valid *or* if that's not the case, whether it's currently resident in lmem.
+ * For migratable and evictable objects, the latter only makes sense when
+ * the object is locked.
+ *
+ * Return: Whether the object migratable but resident in lmem, or not
+ * migratable and will be present in lmem when valid.
+ */
 bool i915_gem_object_is_lmem(struct drm_i915_gem_object *obj)
 {
-	struct intel_memory_region *mr = obj->mm.region;
+	struct intel_memory_region *mr = READ_ONCE(obj->mm.region);
 
+#ifdef CONFIG_LOCKDEP
+	if (i915_gem_object_migratable(obj) &&
+	    i915_gem_object_evictable(obj))
+		assert_object_held(obj);
+#endif
 	return mr && (mr->type == INTEL_MEMORY_LOCAL ||
 		      mr->type == INTEL_MEMORY_STOLEN_LOCAL);
 }