2 files changed, 99 insertions, 2 deletions

diff --git a/drivers/gpu/drm/drm_dp_mst_topology.c b/drivers/gpu/drm/drm_dp_mst_topology.c
index b5976f8c318c..e3497bc49494 100644
--- a/drivers/gpu/drm/drm_dp_mst_topology.c
+++ b/drivers/gpu/drm/drm_dp_mst_topology.c
@@ -3521,10 +3521,11 @@ static void drm_dp_mst_destroy_state(struct drm_private_obj *obj,
         kfree(mst_state);
 }
 
-static const struct drm_private_state_funcs mst_state_funcs = {
+const struct drm_private_state_funcs drm_dp_mst_topology_state_funcs = {
         .atomic_duplicate_state = drm_dp_mst_duplicate_state,
         .atomic_destroy_state = drm_dp_mst_destroy_state,
 };
+EXPORT_SYMBOL(drm_dp_mst_topology_state_funcs);
 
 /**
  * drm_atomic_get_mst_topology_state: get MST topology state
@@ -3608,7 +3609,7 @@ int drm_dp_mst_topology_mgr_init(struct drm_dp_mst_topology_mgr *mgr,
 
         drm_atomic_private_obj_init(dev, &mgr->base,
                                     &mst_state->base,
-                                    &mst_state_funcs);
+                                    &drm_dp_mst_topology_state_funcs);
 
         return 0;
 }
diff --git a/include/drm/drm_dp_mst_helper.h b/include/drm/drm_dp_mst_helper.h
index 8eca5f29242c..581163c8d7d7 100644
--- a/include/drm/drm_dp_mst_helper.h
+++ b/include/drm/drm_dp_mst_helper.h
@@ -650,4 +650,100 @@ int drm_dp_send_power_updown_phy(struct drm_dp_mst_topology_mgr *mgr,
 void drm_dp_mst_get_port_malloc(struct drm_dp_mst_port *port);
 void drm_dp_mst_put_port_malloc(struct drm_dp_mst_port *port);
 
+extern const struct drm_private_state_funcs drm_dp_mst_topology_state_funcs;
+
+/**
+ * __drm_dp_mst_state_iter_get - private atomic state iterator function for
+ * macro-internal use
+ * @state: &struct drm_atomic_state pointer
+ * @mgr: pointer to the &struct drm_dp_mst_topology_mgr iteration cursor
+ * @old_state: optional pointer to the old &struct drm_dp_mst_topology_state
+ * iteration cursor
+ * @new_state: optional pointer to the new &struct drm_dp_mst_topology_state
+ * iteration cursor
+ * @i: int iteration cursor, for macro-internal use
+ *
+ * Used by for_each_oldnew_mst_mgr_in_state(),
+ * for_each_old_mst_mgr_in_state(), and for_each_new_mst_mgr_in_state(). Don't
+ * call this directly.
+ *
+ * Returns:
+ * True if the current &struct drm_private_obj is a &struct
+ * drm_dp_mst_topology_mgr, false otherwise.
+ */
+static inline bool
+__drm_dp_mst_state_iter_get(struct drm_atomic_state *state,
+                            struct drm_dp_mst_topology_mgr **mgr,
+                            struct drm_dp_mst_topology_state **old_state,
+                            struct drm_dp_mst_topology_state **new_state,
+                            int i)
+{
+        struct __drm_private_objs_state *objs_state = &state->private_objs[i];
+
+        if (objs_state->ptr->funcs != &drm_dp_mst_topology_state_funcs)
+                return false;
+
+        *mgr = to_dp_mst_topology_mgr(objs_state->ptr);
+        if (old_state)
+                *old_state = to_dp_mst_topology_state(objs_state->old_state);
+        if (new_state)
+                *new_state = to_dp_mst_topology_state(objs_state->new_state);
+
+        return true;
+}
+
+/**
+ * for_each_oldnew_mst_mgr_in_state - iterate over all DP MST topology
+ * managers in an atomic update
+ * @__state: &struct drm_atomic_state pointer
+ * @mgr: &struct drm_dp_mst_topology_mgr iteration cursor
+ * @old_state: &struct drm_dp_mst_topology_state iteration cursor for the old
+ * state
+ * @new_state: &struct drm_dp_mst_topology_state iteration cursor for the new
+ * state
+ * @__i: int iteration cursor, for macro-internal use
+ *
+ * This iterates over all DRM DP MST topology managers in an atomic update,
+ * tracking both old and new state. This is useful in places where the state
+ * delta needs to be considered, for example in atomic check functions.
+ */
+#define for_each_oldnew_mst_mgr_in_state(__state, mgr, old_state, new_state, __i) \
+        for ((__i) = 0; (__i) < (__state)->num_private_objs; (__i)++) \
+                for_each_if(__drm_dp_mst_state_iter_get((__state), &(mgr), &(old_state), &(new_state), (__i)))
+
+/**
+ * for_each_old_mst_mgr_in_state - iterate over all DP MST topology managers
+ * in an atomic update
+ * @__state: &struct drm_atomic_state pointer
+ * @mgr: &struct drm_dp_mst_topology_mgr iteration cursor
+ * @old_state: &struct drm_dp_mst_topology_state iteration cursor for the old
+ * state
+ * @__i: int iteration cursor, for macro-internal use
+ *
+ * This iterates over all DRM DP MST topology managers in an atomic update,
+ * tracking only the old state. This is useful in disable functions, where we
+ * need the old state the hardware is still in.
+ */
+#define for_each_old_mst_mgr_in_state(__state, mgr, old_state, __i) \
+        for ((__i) = 0; (__i) < (__state)->num_private_objs; (__i)++) \
+                for_each_if(__drm_dp_mst_state_iter_get((__state), &(mgr), &(old_state), NULL, (__i)))
+
+/**
+ * for_each_new_mst_mgr_in_state - iterate over all DP MST topology managers
+ * in an atomic update
+ * @__state: &struct drm_atomic_state pointer
+ * @mgr: &struct drm_dp_mst_topology_mgr iteration cursor
+ * @new_state: &struct drm_dp_mst_topology_state iteration cursor for the new
+ * state
+ * @__i: int iteration cursor, for macro-internal use
+ *
+ * This iterates over all DRM DP MST topology managers in an atomic update,
+ * tracking only the new state. This is useful in enable functions, where we
+ * need the new state the hardware should be in when the atomic commit
+ * operation has completed.
+ */
+#define for_each_new_mst_mgr_in_state(__state, mgr, new_state, __i) \
+        for ((__i) = 0; (__i) < (__state)->num_private_objs; (__i)++) \
+                for_each_if(__drm_dp_mst_state_iter_get((__state), &(mgr), NULL, &(new_state), (__i)))
+
 #endif