gbm: Add support for __DRIimage based getBuffers when available

This lets us allocate color buffers as __DRIimages and pass them into
the driver instead of having to create a __DRIbuffer with the flink
that requires.

With this patch, we can now run gbm on render-nodes.  A render-node is a
drm device that doesn't support modesetting and all the legacy DRI ioctls.
flink is also not supported, but now that gbm doesn't need flink, we can
run piglit on head-less gbm or head-less GPGPU.

Signed-off-by: Kristian Høgsberg <krh@bitplanet.net>
Reviewed-by: Chad Versace <chad.versace@linux.intel.com>
Reviewed-by: Eric Anholt <eric@anholt.net>
Reviewed-by: Jordan Justen <jordan.l.justen@intel.com>
Tested-by: Jordan Justen <jordan.l.justen@intel.com>
Cc: "10.0" <mesa-stable@lists.freedesktop.org>
(cherry picked from commit 04e3ef00dbeab177793954781ddfd298724b6d8d)

2 files changed, 34 insertions, 2 deletions

diff --git a/src/gbm/backends/dri/gbm_dri.c b/src/gbm/backends/dri/gbm_dri.c
index e95fcc7b23c..6c63c75e92d 100644
--- a/src/gbm/backends/dri/gbm_dri.c
+++ b/src/gbm/backends/dri/gbm_dri.c
@@ -104,6 +104,24 @@ dri_get_buffers_with_format(__DRIdrawable * driDrawable,
                                    count, out_count, surf->dri_private);
 }
 
+static int
+image_get_buffers(__DRIdrawable *driDrawable,
+                  unsigned int format,
+                  uint32_t *stamp,
+                  void *loaderPrivate,
+                  uint32_t buffer_mask,
+                  struct __DRIimageList *buffers)
+{
+   struct gbm_dri_surface *surf = loaderPrivate;
+   struct gbm_dri_device *dri = gbm_dri_device(surf->base.gbm);
+
+   if (dri->image_get_buffers == NULL)
+      return 0;
+
+   return dri->image_get_buffers(driDrawable, format, stamp,
+                                 surf->dri_private, buffer_mask, buffers);
+}
+
 static const __DRIuseInvalidateExtension use_invalidate = {
    { __DRI_USE_INVALIDATE, 1 }
 };
@@ -120,6 +138,13 @@ const __DRIdri2LoaderExtension dri2_loader_extension = {
    dri_get_buffers_with_format,
 };
 
+const __DRIimageLoaderExtension image_loader_extension = {
+   { __DRI_IMAGE_LOADER, 1 },
+   image_get_buffers,
+   dri_flush_front_buffer,
+};
+
+
 struct dri_extension_match {
    const char *name;
    int version;
@@ -258,7 +283,8 @@ dri_screen_create(struct gbm_dri_device *dri)
    dri->extensions[0] = &image_lookup_extension.base;
    dri->extensions[1] = &use_invalidate.base;
    dri->extensions[2] = &dri2_loader_extension.base;
-   dri->extensions[3] = NULL;
+   dri->extensions[3] = &image_loader_extension.base;
+   dri->extensions[4] = NULL;
 
    if (dri->dri2 == NULL)
       return -1;
diff --git a/src/gbm/backends/dri/gbm_driint.h b/src/gbm/backends/dri/gbm_driint.h
index cb4e477abf4..fb303a3be55 100644
--- a/src/gbm/backends/dri/gbm_driint.h
+++ b/src/gbm/backends/dri/gbm_driint.h
@@ -52,7 +52,7 @@ struct gbm_dri_device {
    __DRIdri2LoaderExtension *loader;
 
    const __DRIconfig   **driver_configs;
-   const __DRIextension *extensions[4];
+   const __DRIextension *extensions[5];
    const __DRIextension **driver_extensions;
 
    __DRIimage *(*lookup_image)(__DRIscreen *screen, void *image, void *data);
@@ -67,6 +67,12 @@ struct gbm_dri_device {
 			     int *width, int *height,
 			     unsigned int *attachments, int count,
 			     int *out_count, void *data);
+   int (*image_get_buffers)(__DRIdrawable *driDrawable,
+                            unsigned int format,
+                            uint32_t *stamp,
+                            void *loaderPrivate,
+                            uint32_t buffer_mask,
+                            struct __DRIimageList *buffers);
 
    struct wl_drm *wl_drm;
 };