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>

3 files changed, 32 insertions, 2 deletions

diff --git a/include/drm/drm_crtc.h b/include/drm/drm_crtc.h
index fc4767fa723b..1dcfb685d15f 100644
--- a/include/drm/drm_crtc.h
+++ b/include/drm/drm_crtc.h
@@ -902,7 +902,7 @@ struct drm_bridge {
 /**
  * struct struct drm_atomic_state - the global state object for atomic updates
  * @dev: parent DRM device
- * @flags: state flags like async update
+ * @allow_modeset: allow full modeset
  * @planes: pointer to array of plane pointers
  * @plane_states: pointer to array of plane states pointers
  * @crtcs: pointer to array of CRTC pointers
@@ -914,7 +914,7 @@ struct drm_bridge {
  */
 struct drm_atomic_state {
 	struct drm_device *dev;
-	uint32_t flags;
+	bool allow_modeset : 1;
 	struct drm_plane **planes;
 	struct drm_plane_state **plane_states;
 	struct drm_crtc **crtcs;
@@ -1346,6 +1346,10 @@ extern int drm_mode_create_scaling_mode_property(struct drm_device *dev);
 extern int drm_mode_create_aspect_ratio_property(struct drm_device *dev);
 extern int drm_mode_create_dirty_info_property(struct drm_device *dev);
 extern int drm_mode_create_suggested_offset_properties(struct drm_device *dev);
+extern bool drm_property_change_valid_get(struct drm_property *property,
+					 uint64_t value, struct drm_mode_object **ref);
+extern void drm_property_change_valid_put(struct drm_property *property,
+		struct drm_mode_object *ref);
 
 extern int drm_mode_connector_attach_encoder(struct drm_connector *connector,
 					     struct drm_encoder *encoder);
@@ -1437,6 +1441,8 @@ extern int drm_mode_obj_set_property_ioctl(struct drm_device *dev, void *data,
 extern int drm_mode_plane_set_obj_prop(struct drm_plane *plane,
 				       struct drm_property *property,
 				       uint64_t value);
+extern int drm_mode_atomic_ioctl(struct drm_device *dev,
+				 void *data, struct drm_file *file_priv);
 
 extern void drm_fb_get_bpp_depth(uint32_t format, unsigned int *depth,
 				 int *bpp);
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