egl: implement eglQueryDmaBufModifiersEXT

query and return supported dmabuf format modifiers for
EGL_EXT_image_dma_buf_import_modifiers.

v2: move format check to the driver instead of making format queries
   here and then checking.
v3: Check DRIimageExtension version before query (Daniel Stone)
v4:
- move to DRIimageExtension version 15, check queryDmaBufModifiers before
  calling (Jason Ekstrand)
- pass external_only to the driver instead of setting as EGL_TRUE here
  (Emil Velikov, Daniel Stone)

Signed-off-by: Varad Gautam <varad.gautam@collabora.com>
Reviewed-by: Daniel Stone <daniels@collabora.com>
Reviewed-by: Emil Velikov <emil.velikov@collabora.com>
Reviewed-by: Eric Engestrom <eric.engestrom@imgtec.com>
diff --git a/src/egl/drivers/dri2/egl_dri2.c b/src/egl/drivers/dri2/egl_dri2.c
index c271552..bcafdf9 100644
--- a/src/egl/drivers/dri2/egl_dri2.c
+++ b/src/egl/drivers/dri2/egl_dri2.c
@@ -2178,6 +2178,38 @@
    return EGL_TRUE;
 }
 
+static EGLBoolean
+dri2_query_dma_buf_modifiers(_EGLDriver *drv, _EGLDisplay *disp, EGLint format,
+                             EGLint max, EGLuint64KHR *modifiers,
+                             EGLBoolean *external_only, EGLint *count)
+{
+   struct dri2_egl_display *dri2_dpy = dri2_egl_display(disp);
+
+   if (max < 0) {
+      _eglError(EGL_BAD_PARAMETER, "invalid value for max count of formats");
+      return EGL_FALSE;
+   }
+
+   if (max > 0 && modifiers == NULL) {
+      _eglError(EGL_BAD_PARAMETER, "invalid modifiers array");
+      return EGL_FALSE;
+   }
+
+   if (dri2_dpy->image->base.version < 15 ||
+       dri2_dpy->image->queryDmaBufModifiers == NULL)
+      return EGL_FALSE;
+
+   if (dri2_dpy->image->queryDmaBufModifiers(dri2_dpy->dri_screen, format,
+                                             max, modifiers,
+                                             (unsigned int *) external_only,
+                                             count) == false) {
+      _eglError(EGL_BAD_PARAMETER, "invalid format");
+      return EGL_FALSE;
+   }
+
+   return EGL_TRUE;
+}
+
 /**
  * The spec says:
  *
@@ -3116,6 +3148,7 @@
    dri2_drv->base.API.ExportDMABUFImageQueryMESA = dri2_export_dma_buf_image_query_mesa;
    dri2_drv->base.API.ExportDMABUFImageMESA = dri2_export_dma_buf_image_mesa;
    dri2_drv->base.API.QueryDmaBufFormatsEXT = dri2_query_dma_buf_formats;
+   dri2_drv->base.API.QueryDmaBufModifiersEXT = dri2_query_dma_buf_modifiers;
 #endif
 #ifdef HAVE_WAYLAND_PLATFORM
    dri2_drv->base.API.BindWaylandDisplayWL = dri2_bind_wayland_display_wl;