[mutter] cogl/renderer: Add 'is_dma_buf_supported()' vfunc

[Marge Bot <marge-bot src gnome org>]

commit 49ac60e3469700d53605403dc90c2a9bde1596dc
Author: Jonas Ådahl <jadahl gmail com>
Date:   Thu Nov 25 17:15:54 2021 +0100

    cogl/renderer: Add 'is_dma_buf_supported()' vfunc
    
    Returns TRUE if the active renderer backend can allocate DMA buffers.
    This is the case hardware accelerated GBM backends, but FALSE for
    surfaceless (i.e. no render node) and EGLDevice (legacy NVIDIA paths).
    While software based gbm devices can allocate DMA buffers, we don't want
    to allocate them for offscreen rendering, as we really only use these
    for inter process transfers, and as buffers allocated for scanout
    doesn't use the relevant API, making it return FALSE for these solves
    that.
    
    Part-of: <https://gitlab.gnome.org/GNOME/mutter/-/merge_requests/1939>

 cogl/cogl/cogl-renderer.c                  | 11 +++++++++++
 cogl/cogl/cogl-renderer.h                  | 10 ++++++++++
 cogl/cogl/winsys/cogl-winsys-private.h     | 28 ++++++++++++++++++----------
 src/backends/native/meta-renderer-native.c | 23 +++++++++++++++++++++++
 4 files changed, 62 insertions(+), 10 deletions(-)
---
diff --git a/cogl/cogl/cogl-renderer.c b/cogl/cogl/cogl-renderer.c
index 5b37d8634d..38f7a36d77 100644
--- a/cogl/cogl/cogl-renderer.c
+++ b/cogl/cogl/cogl-renderer.c
@@ -773,6 +773,17 @@ cogl_renderer_create_dma_buf (CoglRenderer  *renderer,
   return NULL;
 }
 
+gboolean
+cogl_renderer_is_dma_buf_supported (CoglRenderer *renderer)
+{
+  const CoglWinsysVtable *winsys = _cogl_renderer_get_winsys (renderer);
+
+  if (winsys->renderer_is_dma_buf_supported)
+    return winsys->renderer_is_dma_buf_supported (renderer);
+  else
+    return FALSE;
+}
+
 void
 cogl_renderer_bind_api (CoglRenderer *renderer)
 {
diff --git a/cogl/cogl/cogl-renderer.h b/cogl/cogl/cogl-renderer.h
index 70910c07b4..eef0e40ad3 100644
--- a/cogl/cogl/cogl-renderer.h
+++ b/cogl/cogl/cogl-renderer.h
@@ -419,6 +419,16 @@ cogl_renderer_create_dma_buf (CoglRenderer  *renderer,
                               int            height,
                               GError       **error);
 
+
+/**
+ * cogl_renderer_is_dma_buf_supported: (skip)
+ * @renderer: A #CoglRenderer
+ *
+ * Returns: %TRUE if DMA buffers can be allocated
+ */
+COGL_EXPORT gboolean
+cogl_renderer_is_dma_buf_supported (CoglRenderer *renderer);
+
 /**
  * cogl_renderer_bind_api: (skip)
  */
diff --git a/cogl/cogl/winsys/cogl-winsys-private.h b/cogl/cogl/winsys/cogl-winsys-private.h
index b323a704d4..45aec7ea64 100644
--- a/cogl/cogl/winsys/cogl-winsys-private.h
+++ b/cogl/cogl/winsys/cogl-winsys-private.h
@@ -73,11 +73,12 @@ typedef struct _CoglWinsysVtable
 
   GCallback
   (*renderer_get_proc_address) (CoglRenderer *renderer,
-                                const char *name,
-                                gboolean in_core);
+                                const char   *name,
+                                gboolean      in_core);
 
   gboolean
-  (*renderer_connect) (CoglRenderer *renderer, GError **error);
+  (*renderer_connect) (CoglRenderer *renderer,
+                       GError      **error);
 
   void
   (*renderer_disconnect) (CoglRenderer *renderer);
@@ -86,7 +87,8 @@ typedef struct _CoglWinsysVtable
   (*renderer_outputs_changed) (CoglRenderer *renderer);
 
   gboolean
-  (*display_setup) (CoglDisplay *display, GError **error);
+  (*display_setup) (CoglDisplay *display,
+                    GError     **error);
 
   void
   (*display_destroy) (CoglDisplay *display);
@@ -97,11 +99,15 @@ typedef struct _CoglWinsysVtable
                               int            height,
                               GError       **error);
 
+  gboolean
+  (*renderer_is_dma_buf_supported) (CoglRenderer *renderer);
+
   void
   (*renderer_bind_api) (CoglRenderer *renderer);
 
   gboolean
-  (*context_init) (CoglContext *context, GError **error);
+  (*context_init) (CoglContext *context,
+                   GError     **error);
 
   void
   (*context_deinit) (CoglContext *context);
@@ -115,15 +121,15 @@ typedef struct _CoglWinsysVtable
   (*texture_pixmap_x11_free) (CoglTexturePixmapX11 *tex_pixmap);
 
   gboolean
-  (*texture_pixmap_x11_update) (CoglTexturePixmapX11 *tex_pixmap,
+  (*texture_pixmap_x11_update) (CoglTexturePixmapX11       *tex_pixmap,
                                 CoglTexturePixmapStereoMode stereo_mode,
-                                gboolean needs_mipmap);
+                                gboolean                    needs_mipmap);
 
   void
   (*texture_pixmap_x11_damage_notify) (CoglTexturePixmapX11 *tex_pixmap);
 
   CoglTexture *
-  (*texture_pixmap_x11_get_texture) (CoglTexturePixmapX11 *tex_pixmap,
+  (*texture_pixmap_x11_get_texture) (CoglTexturePixmapX11       *tex_pixmap,
                                      CoglTexturePixmapStereoMode stereo_mode);
 #endif
 
@@ -131,10 +137,12 @@ typedef struct _CoglWinsysVtable
   (*fence_add) (CoglContext *ctx);
 
   gboolean
-  (*fence_is_complete) (CoglContext *ctx, void *fence);
+  (*fence_is_complete) (CoglContext *ctx,
+                        void        *fence);
 
   void
-  (*fence_destroy) (CoglContext *ctx, void *fence);
+  (*fence_destroy) (CoglContext *ctx,
+                    void        *fence);
 
 } CoglWinsysVtable;
 
diff --git a/src/backends/native/meta-renderer-native.c b/src/backends/native/meta-renderer-native.c
index d63ac23bf2..28ea94e9df 100644
--- a/src/backends/native/meta-renderer-native.c
+++ b/src/backends/native/meta-renderer-native.c
@@ -970,6 +970,27 @@ meta_renderer_native_create_dma_buf (CoglRenderer  *cogl_renderer,
   return NULL;
 }
 
+static gboolean
+meta_renderer_native_is_dma_buf_supported (CoglRenderer *cogl_renderer)
+{
+  CoglRendererEGL *cogl_renderer_egl = cogl_renderer->winsys;
+  MetaRendererNativeGpuData *renderer_gpu_data = cogl_renderer_egl->platform;
+  MetaRenderDevice *render_device = renderer_gpu_data->render_device;
+
+  switch (renderer_gpu_data->mode)
+    {
+    case META_RENDERER_NATIVE_MODE_GBM:
+      return meta_render_device_is_hardware_accelerated (render_device);
+    case META_RENDERER_NATIVE_MODE_SURFACELESS:
+#ifdef HAVE_EGL_DEVICE
+    case META_RENDERER_NATIVE_MODE_EGL_DEVICE:
+#endif
+      return FALSE;
+    }
+
+  g_assert_not_reached ();
+}
+
 static gboolean
 meta_renderer_native_init_egl_context (CoglContext *cogl_context,
                                        GError     **error)
@@ -1114,6 +1135,8 @@ get_native_cogl_winsys_vtable (CoglRenderer *cogl_renderer)
       vtable.renderer_connect = meta_renderer_native_connect;
       vtable.renderer_disconnect = meta_renderer_native_disconnect;
       vtable.renderer_create_dma_buf = meta_renderer_native_create_dma_buf;
+      vtable.renderer_is_dma_buf_supported =
+        meta_renderer_native_is_dma_buf_supported;
 
       vtable_inited = TRUE;
     }