render-device: Add API to import other buffers

This more or less is a helper for creating MetaDrmBufferImport objects
with a bit more friendly API.

Part-of: <https://gitlab.gnome.org/GNOME/mutter/-/merge_requests/1854>

src/backends/native/meta-render-device-gbm.c

@@ -27,6 +27,7 @@
 
 #include "backends/meta-backend-private.h"
 #include "backends/native/meta-drm-buffer-gbm.h"
+#include "backends/native/meta-drm-buffer-import.h"
 
 struct _MetaRenderDeviceGbm
 {
@@ -77,6 +78,36 @@ initable_iface_init (GInitableIface *initable_iface)
   initable_iface->init = meta_render_device_gbm_initable_init;
 }
 
+static MetaDrmBuffer *
+meta_render_device_gbm_import_dma_buf (MetaRenderDevice  *render_device,
+                                       MetaDrmBuffer     *buffer,
+                                       GError           **error)
+{
+  MetaRenderDeviceGbm *render_device_gbm =
+    META_RENDER_DEVICE_GBM (render_device);
+  MetaDeviceFile *device_file;
+  MetaDrmBufferGbm *buffer_gbm;
+  MetaDrmBufferImport *buffer_import;
+
+  if (!META_IS_DRM_BUFFER_GBM (buffer))
+    {
+      g_set_error (error, G_IO_ERROR, G_IO_ERROR_NOT_SUPPORTED,
+                   "Can only import gbm backed DMA buffers");
+      return NULL;
+    }
+
+  device_file = meta_render_device_get_device_file (render_device);
+  buffer_gbm = META_DRM_BUFFER_GBM (buffer);
+  buffer_import = meta_drm_buffer_import_new (device_file,
+                                              render_device_gbm->gbm_device,
+                                              buffer_gbm,
+                                              error);
+  if (!buffer_import)
+    return NULL;
+
+  return META_DRM_BUFFER (buffer_import);
+}
+
 static EGLDisplay
 meta_render_device_gbm_create_egl_display (MetaRenderDevice  *render_device,
                                            GError           **error)
@@ -168,6 +199,8 @@ meta_render_device_gbm_class_init (MetaRenderDeviceGbmClass *klass)
     meta_render_device_gbm_create_egl_display;
   render_device_class->allocate_dma_buf =
     meta_render_device_gbm_allocate_dma_buf;
+  render_device_class->import_dma_buf =
+    meta_render_device_gbm_import_dma_buf;
 }
 
 static void

src/backends/native/meta-render-device-private.h

@@ -42,6 +42,9 @@ struct _MetaRenderDeviceClass
                                         uint32_t             format,
                                         MetaDrmBufferFlags   flags,
                                         GError             **error);
+  MetaDrmBuffer * (* import_dma_buf) (MetaRenderDevice  *render_device,
+                                      MetaDrmBuffer     *buffer,
+                                      GError           **error);
 };
 
 #endif /* META_RENDER_DEVICE_PRIVATE_H */

src/backends/native/meta-render-device.c

@@ -364,3 +364,20 @@ meta_render_device_allocate_dma_buf (MetaRenderDevice    *render_device,
 
   return NULL;
 }
+
+MetaDrmBuffer *
+meta_render_device_import_dma_buf (MetaRenderDevice  *render_device,
+                                   MetaDrmBuffer     *buffer,
+                                   GError           **error)
+{
+  MetaRenderDeviceClass *klass = META_RENDER_DEVICE_GET_CLASS (render_device);
+
+  if (klass->import_dma_buf)
+    return klass->import_dma_buf (render_device, buffer, error);
+
+  g_set_error (error, G_IO_ERROR, G_IO_ERROR_FAILED,
+               "Render device '%s' doesn't importing DMA buffers",
+               meta_render_device_get_name (render_device));
+
+  return NULL;
+}

src/backends/native/meta-render-device.h

@@ -48,4 +48,8 @@ MetaDrmBuffer * meta_render_device_allocate_dma_buf (MetaRenderDevice    *render
                                                      MetaDrmBufferFlags   flags,
                                                      GError             **error);
 
+MetaDrmBuffer * meta_render_device_import_dma_buf (MetaRenderDevice  *render_device,
+                                                   MetaDrmBuffer     *buffer,
+                                                   GError           **error);
+
 #endif /* META_RENDER_DEVICE_H */