crtc/kms: Dynamically assign primary and cursor planes

When there are a set of primary planes, and a set of CRTCs, where each
plane can be used on multiple CRTCs, we need to make sure that when we
mode set and page flip, each CRTC gets assigned an individual plane that
isn't used with any other CRTC.

Do this during the monitor resource assignments that sets up later to be
applied configurations of the mode setting objects, but with the new
hooks into the backend, so that we don't need to teach the monitor
config manager about planes.

Closes: https://gitlab.gnome.org/GNOME/mutter/-/issues/2398
Part-of: <https://gitlab.gnome.org/GNOME/mutter/-/merge_requests/3428>

src/backends/native/meta-crtc-kms.c

@@ -51,7 +51,8 @@ struct _MetaCrtcKms
 
   MetaKmsCrtc *kms_crtc;
 
-  MetaKmsPlane *primary_plane;
+  MetaKmsPlane *assigned_primary_plane;
+  MetaKmsPlane *assigned_cursor_plane;
 };
 
 static GQuark kms_crtc_crtc_kms_quark;
@@ -205,14 +206,132 @@ meta_crtc_kms_set_gamma_lut (MetaCrtc           *crtc,
   clutter_stage_schedule_update (CLUTTER_STAGE (stage));
 }
 
+typedef struct _CrtcKmsAssignment
+{
+  MetaKmsPlane *primary_plane;
+  MetaKmsPlane *cursor_plane;
+} CrtcKmsAssignment;
+
+static gboolean
+is_plane_assigned (MetaKmsPlane     *plane,
+                   MetaKmsPlaneType  plane_type,
+                   GPtrArray        *crtc_assignments)
+{
+  size_t i;
+
+  for (i = 0; i < crtc_assignments->len; i++)
+    {
+      MetaCrtcAssignment *assigned_crtc_assignment =
+        g_ptr_array_index (crtc_assignments, i);
+      CrtcKmsAssignment *kms_assignment;
+
+      if (!META_IS_CRTC_KMS (assigned_crtc_assignment->crtc))
+        continue;
+
+      kms_assignment = assigned_crtc_assignment->backend_private;
+      switch (plane_type)
+        {
+        case META_KMS_PLANE_TYPE_PRIMARY:
+          if (kms_assignment->primary_plane == plane)
+            return TRUE;
+          break;
+        case META_KMS_PLANE_TYPE_CURSOR:
+          if (kms_assignment->cursor_plane == plane)
+            return TRUE;
+          break;
+        case META_KMS_PLANE_TYPE_OVERLAY:
+          g_assert_not_reached ();
+        }
+    }
+
+  return FALSE;
+}
+
+static MetaKmsPlane *
+find_unassigned_plane (MetaCrtcKms      *crtc_kms,
+                       MetaKmsPlaneType  kms_plane_type,
+                       GPtrArray        *crtc_assignments)
+{
+  MetaKmsCrtc *kms_crtc = meta_crtc_kms_get_kms_crtc (crtc_kms);
+  MetaKmsDevice *kms_device = meta_kms_crtc_get_device (kms_crtc);
+  GList *l;
+
+  for (l = meta_kms_device_get_planes (kms_device); l; l = l->next)
+    {
+      MetaKmsPlane *kms_plane = l->data;
+
+      if (meta_kms_plane_get_plane_type (kms_plane) != kms_plane_type)
+        continue;
+
+      if (!meta_kms_plane_is_usable_with (kms_plane, kms_crtc))
+        continue;
+
+      if (is_plane_assigned (kms_plane, kms_plane_type,
+                             crtc_assignments))
+        continue;
+
+      return kms_plane;
+    }
+
+  return NULL;
+}
+
+static gboolean
+meta_crtc_kms_assign_extra (MetaCrtc            *crtc,
+                            MetaCrtcAssignment  *crtc_assignment,
+                            GPtrArray           *crtc_assignments,
+                            GError             **error)
+{
+  MetaCrtcKms *crtc_kms = META_CRTC_KMS (crtc);
+  MetaKmsPlane *primary_plane;
+  MetaKmsPlane *cursor_plane;
+  CrtcKmsAssignment *kms_assignment;
+
+  primary_plane = find_unassigned_plane (crtc_kms, META_KMS_PLANE_TYPE_PRIMARY,
+                                         crtc_assignments);
+  if (!primary_plane)
+    {
+      MetaKmsCrtc *kms_crtc = meta_crtc_kms_get_kms_crtc (crtc_kms);
+      MetaKmsDevice *kms_device = meta_kms_crtc_get_device (kms_crtc);
+
+      g_set_error (error, G_IO_ERROR, G_IO_ERROR_FAILED,
+                   "No available primary plane found for CRTC %u (%s)",
+                   meta_kms_crtc_get_id (kms_crtc),
+                   meta_kms_device_get_path (kms_device));
+      return FALSE;
+    }
+
+  cursor_plane = find_unassigned_plane (crtc_kms, META_KMS_PLANE_TYPE_CURSOR,
+                                        crtc_assignments);
+
+  kms_assignment = g_new0 (CrtcKmsAssignment, 1);
+  kms_assignment->primary_plane = primary_plane;
+  kms_assignment->cursor_plane = cursor_plane;
+
+  crtc_assignment->backend_private = kms_assignment;
+  crtc_assignment->backend_private_destroy = g_free;
+
+  return TRUE;
+}
+
+static void
+meta_crtc_kms_set_config (MetaCrtc             *crtc,
+                          const MetaCrtcConfig *config,
+                          gpointer              backend_private)
+{
+  MetaCrtcKms *crtc_kms = META_CRTC_KMS (crtc);
+  CrtcKmsAssignment *kms_assignment = backend_private;
+
+  crtc_kms->assigned_primary_plane = kms_assignment->primary_plane;
+  crtc_kms->assigned_cursor_plane = kms_assignment->cursor_plane;
+}
+
 static gboolean
 is_transform_handled (MetaCrtcKms          *crtc_kms,
                       MetaMonitorTransform  transform)
 {
-  if (!crtc_kms->primary_plane)
-    return FALSE;
 
-  return meta_kms_plane_is_transform_handled (crtc_kms->primary_plane,
+  return meta_kms_plane_is_transform_handled (crtc_kms->assigned_primary_plane,
                                               transform);
 }
 
@@ -222,6 +341,8 @@ meta_crtc_kms_is_transform_handled (MetaCrtcNative       *crtc_native,
 {
   MetaCrtcKms *crtc_kms = META_CRTC_KMS (crtc_native);
 
+  g_return_val_if_fail (crtc_kms->assigned_primary_plane, FALSE);
+
   return is_transform_handled (crtc_kms, transform);
 }
 
@@ -251,7 +372,7 @@ meta_crtc_kms_apply_transform (MetaCrtcKms            *crtc_kms,
   if (!is_transform_handled (crtc_kms, hw_transform))
     return;
 
-  meta_kms_plane_update_set_rotation (crtc_kms->primary_plane,
+  meta_kms_plane_update_set_rotation (crtc_kms->assigned_primary_plane,
                                       kms_plane_assignment,
                                       hw_transform);
 }
@@ -268,7 +389,6 @@ meta_crtc_kms_assign_primary_plane (MetaCrtcKms            *crtc_kms,
   MetaFixed16Rectangle src_rect;
   MtkRectangle dst_rect;
   MetaKmsCrtc *kms_crtc;
-  MetaKmsDevice *kms_device;
   MetaKmsPlane *primary_kms_plane;
   MetaKmsPlaneAssignment *plane_assignment;
 
@@ -289,9 +409,7 @@ meta_crtc_kms_assign_primary_plane (MetaCrtcKms            *crtc_kms,
   };
 
   kms_crtc = meta_crtc_kms_get_kms_crtc (crtc_kms);
-  kms_device = meta_kms_crtc_get_device (kms_crtc);
-  primary_kms_plane = meta_kms_device_get_primary_plane_for (kms_device,
-                                                             kms_crtc);
+  primary_kms_plane = crtc_kms->assigned_primary_plane;
   plane_assignment = meta_kms_update_assign_plane (kms_update,
                                                    kms_crtc,
                                                    primary_kms_plane,
@@ -304,6 +422,12 @@ meta_crtc_kms_assign_primary_plane (MetaCrtcKms            *crtc_kms,
   return plane_assignment;
 }
 
+MetaKmsPlane *
+meta_crtc_kms_get_assigned_cursor_plane (MetaCrtcKms *crtc_kms)
+{
+  return crtc_kms->assigned_cursor_plane;
+}
+
 static GList *
 generate_crtc_connector_list (MetaGpu  *gpu,
                               MetaCrtc *crtc)
@@ -390,7 +514,9 @@ GArray *
 meta_crtc_kms_get_modifiers (MetaCrtcKms *crtc_kms,
                              uint32_t     format)
 {
-  return meta_kms_plane_get_modifiers_for_format (crtc_kms->primary_plane,
+  g_return_val_if_fail (crtc_kms->assigned_primary_plane, NULL);
+
+  return meta_kms_plane_get_modifiers_for_format (crtc_kms->assigned_primary_plane,
                                                   format);
 }
 
@@ -405,7 +531,9 @@ meta_crtc_kms_get_modifiers (MetaCrtcKms *crtc_kms,
 GArray *
 meta_crtc_kms_copy_drm_format_list (MetaCrtcKms *crtc_kms)
 {
-  return meta_kms_plane_copy_drm_format_list (crtc_kms->primary_plane);
+  g_return_val_if_fail (crtc_kms->assigned_primary_plane, NULL);
+
+  return meta_kms_plane_copy_drm_format_list (crtc_kms->assigned_primary_plane);
 }
 
 /**
@@ -419,7 +547,9 @@ gboolean
 meta_crtc_kms_supports_format (MetaCrtcKms *crtc_kms,
                                uint32_t     drm_format)
 {
-  return meta_kms_plane_is_format_supported (crtc_kms->primary_plane,
+  g_return_val_if_fail (crtc_kms->assigned_primary_plane, FALSE);
+
+  return meta_kms_plane_is_format_supported (crtc_kms->assigned_primary_plane,
                                              drm_format);
 }
 
@@ -434,13 +564,8 @@ meta_crtc_kms_new (MetaGpuKms  *gpu_kms,
                    MetaKmsCrtc *kms_crtc)
 {
   MetaGpu *gpu = META_GPU (gpu_kms);
-  MetaKmsDevice *kms_device;
   MetaCrtcKms *crtc_kms;
-  MetaKmsPlane *primary_plane;
 
-  kms_device = meta_gpu_kms_get_kms_device (gpu_kms);
-  primary_plane = meta_kms_device_get_primary_plane_for (kms_device,
-                                                         kms_crtc);
   crtc_kms = g_object_new (META_TYPE_CRTC_KMS,
                            "id", (uint64_t) meta_kms_crtc_get_id (kms_crtc),
                            "backend", meta_gpu_get_backend (gpu),
@@ -448,7 +573,6 @@ meta_crtc_kms_new (MetaGpuKms  *gpu_kms,
                            NULL);
 
   crtc_kms->kms_crtc = kms_crtc;
-  crtc_kms->primary_plane = primary_plane;
 
   if (!kms_crtc_crtc_kms_quark)
     {
@@ -475,6 +599,8 @@ meta_crtc_kms_class_init (MetaCrtcKmsClass *klass)
   crtc_class->get_gamma_lut_size = meta_crtc_kms_get_gamma_lut_size;
   crtc_class->get_gamma_lut = meta_crtc_kms_get_gamma_lut;
   crtc_class->set_gamma_lut = meta_crtc_kms_set_gamma_lut;
+  crtc_class->assign_extra = meta_crtc_kms_assign_extra;
+  crtc_class->set_config = meta_crtc_kms_set_config;
 
   crtc_native_class->is_transform_handled = meta_crtc_kms_is_transform_handled;
   crtc_native_class->is_hw_cursor_supported = meta_crtc_kms_is_hw_cursor_supported;

src/backends/native/meta-crtc-kms.h

@@ -45,6 +45,8 @@ MetaKmsPlaneAssignment * meta_crtc_kms_assign_primary_plane (MetaCrtcKms
                                                              MetaKmsUpdate          *kms_update,
                                                              MetaKmsAssignPlaneFlag  flags);
 
+MetaKmsPlane * meta_crtc_kms_get_assigned_cursor_plane (MetaCrtcKms *crtc_kms);
+
 void meta_crtc_kms_set_mode (MetaCrtcKms   *crtc_kms,
                              MetaKmsUpdate *kms_update);
 

src/backends/native/meta-kms-cursor-manager.c

@@ -45,6 +45,7 @@ typedef struct _CrtcStateImpl
   MetaKmsCursorManagerImpl *cursor_manager_impl;
 
   MetaKmsCrtc *crtc;
+  MetaKmsPlane *cursor_plane;
   graphene_rect_t layout;
   float scale;
   MetaMonitorTransform transform;
@@ -97,6 +98,7 @@ find_crtc_state (MetaKmsCursorManagerImpl *cursor_manager_impl,
 static CrtcStateImpl *
 crtc_state_impl_new (MetaKmsCursorManagerImpl *cursor_manager_impl,
                      MetaKmsCrtc              *crtc,
+                     MetaKmsPlane             *cursor_plane,
                      graphene_rect_t           layout,
                      float                     scale,
                      MetaDrmBuffer            *buffer)
@@ -107,6 +109,7 @@ crtc_state_impl_new (MetaKmsCursorManagerImpl *cursor_manager_impl,
   g_atomic_ref_count_init (&crtc_state_impl->ref_count);
   crtc_state_impl->cursor_manager_impl = cursor_manager_impl;
   crtc_state_impl->crtc = crtc;
+  crtc_state_impl->cursor_plane = cursor_plane;
   crtc_state_impl->layout = layout;
   crtc_state_impl->scale = scale;
   crtc_state_impl->buffer = buffer;
@@ -365,7 +368,7 @@ maybe_update_cursor_plane (MetaKmsCursorManagerImpl  *cursor_manager_impl,
       meta_kms_update_realize (update, impl_device);
     }
 
-  cursor_plane = meta_kms_device_get_cursor_plane_for (device, crtc);
+  cursor_plane = crtc_state_impl->cursor_plane;
 
   if (should_have_cursor)
     {
@@ -838,6 +841,7 @@ update_viewports_in_impl (MetaThreadImpl  *thread_impl,
           crtc_state_impl =
             crtc_state_impl_new (cursor_manager_impl,
                                  crtc_layout->crtc,
+                                 crtc_layout->cursor_plane,
                                  crtc_layout->layout,
                                  crtc_layout->scale,
                                  g_steal_pointer (&old_crtc_state->buffer));
@@ -847,6 +851,7 @@ update_viewports_in_impl (MetaThreadImpl  *thread_impl,
           crtc_state_impl =
             crtc_state_impl_new (cursor_manager_impl,
                                  crtc_layout->crtc,
+                                 crtc_layout->cursor_plane,
                                  crtc_layout->layout,
                                  crtc_layout->scale,
                                  NULL);

src/backends/native/meta-kms-cursor-manager.h

@@ -28,6 +28,7 @@
 typedef struct _MetaKmsCrtcLayout
 {
   MetaKmsCrtc *crtc;
+  MetaKmsPlane *cursor_plane;
   graphene_rect_t layout;
   float scale;
 } MetaKmsCrtcLayout;

src/backends/native/meta-renderer-native.c

@@ -1122,23 +1122,27 @@ meta_renderer_native_queue_modes_reset (MetaRendererNative *renderer_native)
           MetaOnscreenNative *onscreen_native =
             META_ONSCREEN_NATIVE (framebuffer);
           MetaCrtc *crtc;
+          MetaCrtcKms *crtc_kms;
           MetaKmsCrtc *kms_crtc;
+          MetaKmsPlane *kms_plane;
           MtkRectangle view_layout;
           float view_scale;
           MetaKmsCrtcLayout crtc_layout;
 
-          renderer_native->pending_mode_set_views =
-            g_list_prepend (renderer_native->pending_mode_set_views,
-                            stage_view);
-          meta_onscreen_native_invalidate (onscreen_native);
           crtc = meta_onscreen_native_get_crtc (onscreen_native);
-          kms_crtc = meta_crtc_kms_get_kms_crtc (META_CRTC_KMS (crtc));
+          crtc_kms = META_CRTC_KMS (crtc);
+
+          kms_plane = meta_crtc_kms_get_assigned_cursor_plane (crtc_kms);
+          if (!kms_plane)
+            continue;
+          kms_crtc = meta_crtc_kms_get_kms_crtc (crtc_kms);
 
           clutter_stage_view_get_layout (stage_view, &view_layout);
           view_scale = clutter_stage_view_get_scale (stage_view);
 
           crtc_layout = (MetaKmsCrtcLayout) {
             .crtc = kms_crtc,
+            .cursor_plane = kms_plane,
             .layout = GRAPHENE_RECT_INIT (view_layout.x,
                                           view_layout.y,
                                           view_layout.width,
@@ -1146,6 +1150,11 @@ meta_renderer_native_queue_modes_reset (MetaRendererNative *renderer_native)
             .scale = view_scale,
           };
           g_array_append_val (crtc_layouts, crtc_layout);
+
+          meta_onscreen_native_invalidate (onscreen_native);
+          renderer_native->pending_mode_set_views =
+            g_list_prepend (renderer_native->pending_mode_set_views,
+                            stage_view);
         }
     }
   renderer_native->pending_mode_set = TRUE;