drm: Atomic modeset ioctl

The atomic modeset ioctl can be used to push any number of new values
for object properties. The driver can then check the full device
configuration as single unit, and try to apply the changes atomically.

The ioctl simply takes a list of object IDs and property IDs and their
values.

Originally based on a patch from Ville Syrjälä, although it has mutated
(mutilated?) enough since then that you probably shouldn't blame it on
him ;-)

The atomic support is hidden behind the DRM_CLIENT_CAP_ATOMIC cap (to
protect legacy userspace) and drm.atomic module param (for now).

v2: Check for file_priv->atomic to make sure we only allow userspace
in-the-know to use atomic.

Signed-off-by: Rob Clark <robdclark@gmail.com>
Reviewed-by: Sean Paul <seanpaul@chromium.org>
Reviewed-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>

2 files changed, 24 insertions, 0 deletions

diff --git a/include/uapi/drm/drm.h b/include/uapi/drm/drm.h
index f7b2baf7ecb2..01b2d6d0e355 100644
--- a/include/uapi/drm/drm.h
+++ b/include/uapi/drm/drm.h
@@ -784,6 +784,7 @@ struct drm_prime_handle {
 #define DRM_IOCTL_MODE_OBJ_GETPROPERTIES        DRM_IOWR(0xB9, struct drm_mode_obj_get_properties)
 #define DRM_IOCTL_MODE_OBJ_SETPROPERTY  DRM_IOWR(0xBA, struct drm_mode_obj_set_property)
 #define DRM_IOCTL_MODE_CURSOR2          DRM_IOWR(0xBB, struct drm_mode_cursor2)
+#define DRM_IOCTL_MODE_ATOMIC           DRM_IOWR(0xBC, struct drm_mode_atomic)
 
 /**
  * Device specific ioctls should only be in their respective headers
diff --git a/include/uapi/drm/drm_mode.h b/include/uapi/drm/drm_mode.h
index b8f9c0f2e7fe..ca788e01dab2 100644
--- a/include/uapi/drm/drm_mode.h
+++ b/include/uapi/drm/drm_mode.h
@@ -526,4 +526,27 @@ struct drm_mode_destroy_dumb {
         uint32_t handle;
 };
 
+/* page-flip flags are valid, plus: */
+#define DRM_MODE_ATOMIC_TEST_ONLY 0x0100
+#define DRM_MODE_ATOMIC_NONBLOCK  0x0200
+#define DRM_MODE_ATOMIC_ALLOW_MODESET 0x0400
+
+#define DRM_MODE_ATOMIC_FLAGS (\
+                DRM_MODE_PAGE_FLIP_EVENT |\
+                DRM_MODE_PAGE_FLIP_ASYNC |\
+                DRM_MODE_ATOMIC_TEST_ONLY |\
+                DRM_MODE_ATOMIC_NONBLOCK |\
+                DRM_MODE_ATOMIC_ALLOW_MODESET)
+
+struct drm_mode_atomic {
+        __u32 flags;
+        __u32 count_objs;
+        __u64 objs_ptr;
+        __u64 count_props_ptr;
+        __u64 props_ptr;
+        __u64 prop_values_ptr;
+        __u64 reserved;
+        __u64 user_data;
+};
+
 #endif