drm: dumb scanout create/mmap for intel/radeon (v3)

This is just an idea that might or might not be a good idea,
it basically adds two ioctls to create a dumb and map a dumb buffer
suitable for scanout. The handle can be passed to the KMS ioctls to create
a framebuffer.

It looks to me like it would be useful in the following cases:
a) in development drivers - we can always provide a shadowfb fallback.
b) libkms users - we can clean up libkms a lot and avoid linking
to libdrm_*.
c) plymouth via libkms is a lot easier.

Userspace bits would be just calls + mmaps. We could probably
mark these handles somehow as not being suitable for acceleartion
so as top stop people who are dumber than dumb.

Signed-off-by: Dave Airlie <airlied@redhat.com>

1 files changed, 7 insertions, 0 deletions

diff --git a/include/drm/drm_crtc.h b/include/drm/drm_crtc.h
index 801be59f4f15..080a6e33470e 100644
--- a/include/drm/drm_crtc.h
+++ b/include/drm/drm_crtc.h
@@ -798,4 +798,11 @@ extern int drm_add_modes_noedid(struct drm_connector *connector,
 extern bool drm_edid_is_valid(struct edid *edid);
 struct drm_display_mode *drm_mode_find_dmt(struct drm_device *dev,
                                            int hsize, int vsize, int fresh);
+
+extern int drm_mode_create_dumb_ioctl(struct drm_device *dev,
+                                      void *data, struct drm_file *file_priv);
+extern int drm_mode_mmap_dumb_ioctl(struct drm_device *dev,
+                                    void *data, struct drm_file *file_priv);
+extern int drm_mode_destroy_dumb_ioctl(struct drm_device *dev,
+                                      void *data, struct drm_file *file_priv);
 #endif /* __DRM_CRTC_H__ */