vmwgfx: Porting over new drm and ttm files

This is the one large DRM and vmwgfx port from kernel 4.6+ to
vmwgfx stand alone.  The code is not quite v4.7, but some of
the structures have been ported over.

Signed-off-by: Sinclair Yeh <syeh@vmware.com>
Signed-off-by: Thomas Hellstrom <thellstrom@vmware.com>

1 files changed, 3020 insertions, 0 deletions

diff --git a/drm_atomic_helper.c b/drm_atomic_helper.c
new file mode 100644
index 0000000..2b3b2c1
--- /dev/null
+++ b/drm_atomic_helper.c
@@ -0,0 +1,3020 @@
+/*
+ * Copyright (C) 2014 Red Hat
+ * Copyright (C) 2014 Intel Corp.
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a
+ * copy of this software and associated documentation files (the "Software"),
+ * to deal in the Software without restriction, including without limitation
+ * the rights to use, copy, modify, merge, publish, distribute, sublicense,
+ * and/or sell copies of the Software, and to permit persons to whom the
+ * Software is furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in
+ * all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL
+ * THE COPYRIGHT HOLDER(S) OR AUTHOR(S) BE LIABLE FOR ANY CLAIM, DAMAGES OR
+ * OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE,
+ * ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR
+ * OTHER DEALINGS IN THE SOFTWARE.
+ *
+ * Authors:
+ * Rob Clark <robdclark@gmail.com>
+ * Daniel Vetter <daniel.vetter@ffwll.ch>
+ */
+
+#include "drmP.h"
+#include "drm_atomic.h"
+#include "drm_plane_helper.h"
+#include "drm_crtc_helper.h"
+#include "drm_atomic_helper.h"
+#include <linux/fence.h>
+
+/**
+ * DOC: overview
+ *
+ * This helper library provides implementations of check and commit functions on
+ * top of the CRTC modeset helper callbacks and the plane helper callbacks. It
+ * also provides convenience implementations for the atomic state handling
+ * callbacks for drivers which don't need to subclass the drm core structures to
+ * add their own additional internal state.
+ *
+ * This library also provides default implementations for the check callback in
+ * drm_atomic_helper_check() and for the commit callback with
+ * drm_atomic_helper_commit(). But the individual stages and callbacks are
+ * exposed to allow drivers to mix and match and e.g. use the plane helpers only
+ * together with a driver private modeset implementation.
+ *
+ * This library also provides implementations for all the legacy driver
+ * interfaces on top of the atomic interface. See drm_atomic_helper_set_config(),
+ * drm_atomic_helper_disable_plane(), drm_atomic_helper_disable_plane() and the
+ * various functions to implement set_property callbacks. New drivers must not
+ * implement these functions themselves but must use the provided helpers.
+ *
+ * The atomic helper uses the same function table structures as all other
+ * modesetting helpers. See the documentation for struct &drm_crtc_helper_funcs,
+ * struct &drm_encoder_helper_funcs and struct &drm_connector_helper_funcs. It
+ * also shares the struct &drm_plane_helper_funcs function table with the plane
+ * helpers.
+ */
+static void
+drm_atomic_helper_plane_changed(struct drm_atomic_state *state,
+				struct drm_plane_state *plane_state,
+				struct drm_plane *plane)
+{
+	struct drm_crtc_state *crtc_state;
+
+	if (plane->state->crtc) {
+		crtc_state = drm_atomic_get_existing_crtc_state(state,
+								plane->state->crtc);
+
+		if (WARN_ON(!crtc_state))
+			return;
+
+		crtc_state->planes_changed = true;
+	}
+
+	if (plane_state->crtc) {
+		crtc_state = drm_atomic_get_existing_crtc_state(state,
+								plane_state->crtc);
+
+		if (WARN_ON(!crtc_state))
+			return;
+
+		crtc_state->planes_changed = true;
+	}
+}
+
+static int handle_conflicting_encoders(struct drm_atomic_state *state,
+				       bool disable_conflicting_encoders)
+{
+	struct drm_connector_state *conn_state;
+	struct drm_connector *connector;
+	struct drm_encoder *encoder;
+	unsigned encoder_mask = 0;
+	int i, ret;
+
+	/*
+	 * First loop, find all newly assigned encoders from the connectors
+	 * part of the state. If the same encoder is assigned to multiple
+	 * connectors bail out.
+	 */
+	for_each_connector_in_state(state, connector, conn_state, i) {
+		const struct drm_connector_helper_funcs *funcs = connector->helper_private;
+		struct drm_encoder *new_encoder;
+
+		if (!conn_state->crtc)
+			continue;
+
+		if (funcs->atomic_best_encoder)
+			new_encoder = funcs->atomic_best_encoder(connector, conn_state);
+		else
+			new_encoder = funcs->best_encoder(connector);
+
+		if (new_encoder) {
+			if (encoder_mask & (1 << drm_encoder_index(new_encoder))) {
+				DRM_DEBUG_ATOMIC("[ENCODER:%d:%s] on [CONNECTOR:%d:%s] already assigned\n",
+					new_encoder->base.id, new_encoder->name,
+					connector->base.id, connector->name);
+
+				return -EINVAL;
+			}
+
+			encoder_mask |= 1 << drm_encoder_index(new_encoder);
+		}
+	}
+
+	if (!encoder_mask)
+		return 0;
+
+	/*
+	 * Second loop, iterate over all connectors not part of the state.
+	 *
+	 * If a conflicting encoder is found and disable_conflicting_encoders
+	 * is not set, an error is returned. Userspace can provide a solution
+	 * through the atomic ioctl.
+	 *
+	 * If the flag is set conflicting connectors are removed from the crtc
+	 * and the crtc is disabled if no encoder is left. This preserves
+	 * compatibility with the legacy set_config behavior.
+	 */
+	drm_for_each_connector(connector, state->dev) {
+		struct drm_crtc_state *crtc_state;
+
+		if (drm_atomic_get_existing_connector_state(state, connector))
+			continue;
+
+		encoder = connector->state->best_encoder;
+		if (!encoder || !(encoder_mask & (1 << drm_encoder_index(encoder))))
+			continue;
+
+		if (!disable_conflicting_encoders) {
+			DRM_DEBUG_ATOMIC("[ENCODER:%d:%s] in use on [CRTC:%d:%s] by [CONNECTOR:%d:%s]\n",
+					 encoder->base.id, encoder->name,
+					 connector->state->crtc->base.id,
+					 connector->state->crtc->name,
+					 connector->base.id, connector->name);
+			return -EINVAL;
+		}
+
+		conn_state = drm_atomic_get_connector_state(state, connector);
+		if (IS_ERR(conn_state))
+			return PTR_ERR(conn_state);
+
+		DRM_DEBUG_ATOMIC("[ENCODER:%d:%s] in use on [CRTC:%d:%s], disabling [CONNECTOR:%d:%s]\n",
+				 encoder->base.id, encoder->name,
+				 conn_state->crtc->base.id, conn_state->crtc->name,
+				 connector->base.id, connector->name);
+
+		crtc_state = drm_atomic_get_existing_crtc_state(state, conn_state->crtc);
+
+		ret = drm_atomic_set_crtc_for_connector(conn_state, NULL);
+		if (ret)
+			return ret;
+
+		if (!crtc_state->connector_mask) {
+			ret = drm_atomic_set_mode_prop_for_crtc(crtc_state,
+								NULL);
+			if (ret < 0)
+				return ret;
+
+			crtc_state->active = false;
+		}
+	}
+
+	return 0;
+}
+
+static void
+set_best_encoder(struct drm_atomic_state *state,
+		 struct drm_connector_state *conn_state,
+		 struct drm_encoder *encoder)
+{
+	struct drm_crtc_state *crtc_state;
+	struct drm_crtc *crtc;
+
+	if (conn_state->best_encoder) {
+		/* Unset the encoder_mask in the old crtc state. */
+		crtc = conn_state->connector->state->crtc;
+
+		/* A NULL crtc is an error here because we should have
+		 *  duplicated a NULL best_encoder when crtc was NULL.
+		 * As an exception restoring duplicated atomic state
+		 * during resume is allowed, so don't warn when
+		 * best_encoder is equal to encoder we intend to set.
+		 */
+		WARN_ON(!crtc && encoder != conn_state->best_encoder);
+		if (crtc) {
+			crtc_state = drm_atomic_get_existing_crtc_state(state, crtc);
+
+			crtc_state->encoder_mask &=
+				~(1 << drm_encoder_index(conn_state->best_encoder));
+		}
+	}
+
+	if (encoder) {
+		crtc = conn_state->crtc;
+		WARN_ON(!crtc);
+		if (crtc) {
+			crtc_state = drm_atomic_get_existing_crtc_state(state, crtc);
+
+			crtc_state->encoder_mask |=
+				1 << drm_encoder_index(encoder);
+		}
+	}
+
+	conn_state->best_encoder = encoder;
+}
+
+static void
+steal_encoder(struct drm_atomic_state *state,
+	      struct drm_encoder *encoder)
+{
+	struct drm_crtc_state *crtc_state;
+	struct drm_connector *connector;
+	struct drm_connector_state *connector_state;
+	int i;
+
+	for_each_connector_in_state(state, connector, connector_state, i) {
+		struct drm_crtc *encoder_crtc;
+
+		if (connector_state->best_encoder != encoder)
+			continue;
+
+		encoder_crtc = connector->state->crtc;
+
+		DRM_DEBUG_ATOMIC("[ENCODER:%d:%s] in use on [CRTC:%d:%s], stealing it\n",
+				 encoder->base.id, encoder->name,
+				 encoder_crtc->base.id, encoder_crtc->name);
+
+		set_best_encoder(state, connector_state, NULL);
+
+		crtc_state = drm_atomic_get_existing_crtc_state(state, encoder_crtc);
+		crtc_state->connectors_changed = true;
+
+		return;
+	}
+}
+
+static int
+update_connector_routing(struct drm_atomic_state *state,
+			 struct drm_connector *connector,
+			 struct drm_connector_state *connector_state)
+{
+	const struct drm_connector_helper_funcs *funcs;
+	struct drm_encoder *new_encoder;
+	struct drm_crtc_state *crtc_state;
+
+	DRM_DEBUG_ATOMIC("Updating routing for [CONNECTOR:%d:%s]\n",
+			 connector->base.id,
+			 connector->name);
+
+	if (connector->state->crtc != connector_state->crtc) {
+		if (connector->state->crtc) {
+			crtc_state = drm_atomic_get_existing_crtc_state(state, connector->state->crtc);
+			crtc_state->connectors_changed = true;
+		}
+
+		if (connector_state->crtc) {
+			crtc_state = drm_atomic_get_existing_crtc_state(state, connector_state->crtc);
+			crtc_state->connectors_changed = true;
+		}
+	}
+
+	if (!connector_state->crtc) {
+		DRM_DEBUG_ATOMIC("Disabling [CONNECTOR:%d:%s]\n",
+				connector->base.id,
+				connector->name);
+
+		set_best_encoder(state, connector_state, NULL);
+
+		return 0;
+	}
+
+	funcs = connector->helper_private;
+
+	if (funcs->atomic_best_encoder)
+		new_encoder = funcs->atomic_best_encoder(connector,
+							 connector_state);
+	else
+		new_encoder = funcs->best_encoder(connector);
+
+	if (!new_encoder) {
+		DRM_DEBUG_ATOMIC("No suitable encoder found for [CONNECTOR:%d:%s]\n",
+				 connector->base.id,
+				 connector->name);
+		return -EINVAL;
+	}
+
+	if (!drm_encoder_crtc_ok(new_encoder, connector_state->crtc)) {
+		DRM_DEBUG_ATOMIC("[ENCODER:%d:%s] incompatible with [CRTC:%d]\n",
+				 new_encoder->base.id,
+				 new_encoder->name,
+				 connector_state->crtc->base.id);
+		return -EINVAL;
+	}
+
+	if (new_encoder == connector_state->best_encoder) {
+		set_best_encoder(state, connector_state, new_encoder);
+
+		DRM_DEBUG_ATOMIC("[CONNECTOR:%d:%s] keeps [ENCODER:%d:%s], now on [CRTC:%d:%s]\n",
+				 connector->base.id,
+				 connector->name,
+				 new_encoder->base.id,
+				 new_encoder->name,
+				 connector_state->crtc->base.id,
+				 connector_state->crtc->name);
+
+		return 0;
+	}
+
+	steal_encoder(state, new_encoder);
+
+	set_best_encoder(state, connector_state, new_encoder);
+
+	crtc_state = drm_atomic_get_existing_crtc_state(state, connector_state->crtc);
+	crtc_state->connectors_changed = true;
+
+	DRM_DEBUG_ATOMIC("[CONNECTOR:%d:%s] using [ENCODER:%d:%s] on [CRTC:%d:%s]\n",
+			 connector->base.id,
+			 connector->name,
+			 new_encoder->base.id,
+			 new_encoder->name,
+			 connector_state->crtc->base.id,
+			 connector_state->crtc->name);
+
+	return 0;
+}
+
+static int
+mode_fixup(struct drm_atomic_state *state)
+{
+	struct drm_crtc *crtc;
+	struct drm_crtc_state *crtc_state;
+	struct drm_connector *connector;
+	struct drm_connector_state *conn_state;
+	int i;
+	bool ret;
+
+	for_each_crtc_in_state(state, crtc, crtc_state, i) {
+		if (!crtc_state->mode_changed &&
+		    !crtc_state->connectors_changed)
+			continue;
+
+		drm_mode_copy(&crtc_state->adjusted_mode, &crtc_state->mode);
+	}
+
+	for_each_connector_in_state(state, connector, conn_state, i) {
+		const struct drm_encoder_helper_funcs *funcs;
+		struct drm_encoder *encoder;
+
+		WARN_ON(!!conn_state->best_encoder != !!conn_state->crtc);
+
+		if (!conn_state->crtc || !conn_state->best_encoder)
+			continue;
+
+		crtc_state = drm_atomic_get_existing_crtc_state(state,
+								conn_state->crtc);
+
+		/*
+		 * Each encoder has at most one connector (since we always steal
+		 * it away), so we won't call ->mode_fixup twice.
+		 */
+		encoder = conn_state->best_encoder;
+		funcs = encoder->helper_private;
+
+		ret = drm_bridge_mode_fixup(encoder->bridge, &crtc_state->mode,
+				&crtc_state->adjusted_mode);
+		if (!ret) {
+			DRM_DEBUG_ATOMIC("Bridge fixup failed\n");
+			return -EINVAL;
+		}
+
+		if (funcs && funcs->atomic_check) {
+			ret = funcs->atomic_check(encoder, crtc_state,
+						  conn_state);
+			if (ret) {
+				DRM_DEBUG_ATOMIC("[ENCODER:%d:%s] check failed\n",
+						 encoder->base.id, encoder->name);
+				return ret;
+			}
+		} else if (funcs && funcs->mode_fixup) {
+			ret = funcs->mode_fixup(encoder, &crtc_state->mode,
+						&crtc_state->adjusted_mode);
+			if (!ret) {
+				DRM_DEBUG_ATOMIC("[ENCODER:%d:%s] fixup failed\n",
+						 encoder->base.id, encoder->name);
+				return -EINVAL;
+			}
+		}
+	}
+
+	for_each_crtc_in_state(state, crtc, crtc_state, i) {
+		const struct drm_crtc_helper_funcs *funcs;
+
+		if (!crtc_state->mode_changed &&
+		    !crtc_state->connectors_changed)
+			continue;
+
+		funcs = crtc->helper_private;
+		if (!funcs->mode_fixup)
+			continue;
+
+		ret = funcs->mode_fixup(crtc, &crtc_state->mode,
+					&crtc_state->adjusted_mode);
+		if (!ret) {
+			DRM_DEBUG_ATOMIC("[CRTC:%d:%s] fixup failed\n",
+					 crtc->base.id, crtc->name);
+			return -EINVAL;
+		}
+	}
+
+	return 0;
+}
+
+/**
+ * drm_atomic_helper_check_modeset - validate state object for modeset changes
+ * @dev: DRM device
+ * @state: the driver state object
+ *
+ * Check the state object to see if the requested state is physically possible.
+ * This does all the crtc and connector related computations for an atomic
+ * update and adds any additional connectors needed for full modesets and calls
+ * down into ->mode_fixup functions of the driver backend.
+ *
+ * crtc_state->mode_changed is set when the input mode is changed.
+ * crtc_state->connectors_changed is set when a connector is added or
+ * removed from the crtc.
+ * crtc_state->active_changed is set when crtc_state->active changes,
+ * which is used for dpms.
+ *
+ * IMPORTANT:
+ *
+ * Drivers which update ->mode_changed (e.g. in their ->atomic_check hooks if a
+ * plane update can't be done without a full modeset) _must_ call this function
+ * afterwards after that change. It is permitted to call this function multiple
+ * times for the same update, e.g. when the ->atomic_check functions depend upon
+ * the adjusted dotclock for fifo space allocation and watermark computation.
+ *
+ * RETURNS
+ * Zero for success or -errno
+ */
+int
+drm_atomic_helper_check_modeset(struct drm_device *dev,
+				struct drm_atomic_state *state)
+{
+	struct drm_crtc *crtc;
+	struct drm_crtc_state *crtc_state;
+	struct drm_connector *connector;
+	struct drm_connector_state *connector_state;
+	int i, ret;
+
+	for_each_crtc_in_state(state, crtc, crtc_state, i) {
+		if (!drm_mode_equal(&crtc->state->mode, &crtc_state->mode)) {
+			DRM_DEBUG_ATOMIC("[CRTC:%d:%s] mode changed\n",
+					 crtc->base.id, crtc->name);
+			crtc_state->mode_changed = true;
+		}
+
+		if (crtc->state->enable != crtc_state->enable) {
+			DRM_DEBUG_ATOMIC("[CRTC:%d:%s] enable changed\n",
+					 crtc->base.id, crtc->name);
+
+			/*
+			 * For clarity this assignment is done here, but
+			 * enable == 0 is only true when there are no
+			 * connectors and a NULL mode.
+			 *
+			 * The other way around is true as well. enable != 0
+			 * iff connectors are attached and a mode is set.
+			 */
+			crtc_state->mode_changed = true;
+			crtc_state->connectors_changed = true;
+		}
+	}
+
+	ret = handle_conflicting_encoders(state, state->legacy_set_config);
+	if (ret)
+		return ret;
+
+	for_each_connector_in_state(state, connector, connector_state, i) {
+		/*
+		 * This only sets crtc->mode_changed for routing changes,
+		 * drivers must set crtc->mode_changed themselves when connector
+		 * properties need to be updated.
+		 */
+		ret = update_connector_routing(state, connector,
+					       connector_state);
+		if (ret)
+			return ret;
+	}
+
+	/*
+	 * After all the routing has been prepared we need to add in any
+	 * connector which is itself unchanged, but who's crtc changes it's
+	 * configuration. This must be done before calling mode_fixup in case a
+	 * crtc only changed its mode but has the same set of connectors.
+	 */
+	for_each_crtc_in_state(state, crtc, crtc_state, i) {
+		bool has_connectors =
+			!!crtc_state->connector_mask;
+
+		/*
+		 * We must set ->active_changed after walking connectors for
+		 * otherwise an update that only changes active would result in
+		 * a full modeset because update_connector_routing force that.
+		 */
+		if (crtc->state->active != crtc_state->active) {
+			DRM_DEBUG_ATOMIC("[CRTC:%d:%s] active changed\n",
+					 crtc->base.id, crtc->name);
+			crtc_state->active_changed = true;
+		}
+
+		if (!drm_atomic_crtc_needs_modeset(crtc_state))
+			continue;
+
+		DRM_DEBUG_ATOMIC("[CRTC:%d:%s] needs all connectors, enable: %c, active: %c\n",
+				 crtc->base.id, crtc->name,
+				 crtc_state->enable ? 'y' : 'n',
+				 crtc_state->active ? 'y' : 'n');
+
+		ret = drm_atomic_add_affected_connectors(state, crtc);
+		if (ret != 0)
+			return ret;
+
+		ret = drm_atomic_add_affected_planes(state, crtc);
+		if (ret != 0)
+			return ret;
+
+		if (crtc_state->enable != has_connectors) {
+			DRM_DEBUG_ATOMIC("[CRTC:%d:%s] enabled/connectors mismatch\n",
+					 crtc->base.id, crtc->name);
+
+			return -EINVAL;
+		}
+	}
+
+	return mode_fixup(state);
+}
+EXPORT_SYMBOL(drm_atomic_helper_check_modeset);
+
+/**
+ * drm_atomic_helper_check_planes - validate state object for planes changes
+ * @dev: DRM device
+ * @state: the driver state object
+ *
+ * Check the state object to see if the requested state is physically possible.
+ * This does all the plane update related checks using by calling into the
+ * ->atomic_check hooks provided by the driver.
+ *
+ * It also sets crtc_state->planes_changed to indicate that a crtc has
+ * updated planes.
+ *
+ * RETURNS
+ * Zero for success or -errno
+ */
+int
+drm_atomic_helper_check_planes(struct drm_device *dev,
+			       struct drm_atomic_state *state)
+{
+	struct drm_crtc *crtc;
+	struct drm_crtc_state *crtc_state;
+	struct drm_plane *plane;
+	struct drm_plane_state *plane_state;
+	int i, ret = 0;
+
+	for_each_plane_in_state(state, plane, plane_state, i) {
+		const struct drm_plane_helper_funcs *funcs;
+
+		funcs = plane->helper_private;
+
+		drm_atomic_helper_plane_changed(state, plane_state, plane);
+
+		if (!funcs || !funcs->atomic_check)
+			continue;
+
+		ret = funcs->atomic_check(plane, plane_state);
+		if (ret) {
+			DRM_DEBUG_ATOMIC("[PLANE:%d:%s] atomic driver check failed\n",
+					 plane->base.id, plane->name);
+			return ret;
+		}
+	}
+
+	for_each_crtc_in_state(state, crtc, crtc_state, i) {
+		const struct drm_crtc_helper_funcs *funcs;
+
+		funcs = crtc->helper_private;
+
+		if (!funcs || !funcs->atomic_check)
+			continue;
+
+		ret = funcs->atomic_check(crtc, state->crtc_states[i]);
+		if (ret) {
+			DRM_DEBUG_ATOMIC("[CRTC:%d:%s] atomic driver check failed\n",
+					 crtc->base.id, crtc->name);
+			return ret;
+		}
+	}
+
+	return ret;
+}
+EXPORT_SYMBOL(drm_atomic_helper_check_planes);
+
+/**
+ * drm_atomic_helper_check - validate state object
+ * @dev: DRM device
+ * @state: the driver state object
+ *
+ * Check the state object to see if the requested state is physically possible.
+ * Only crtcs and planes have check callbacks, so for any additional (global)
+ * checking that a driver needs it can simply wrap that around this function.
+ * Drivers without such needs can directly use this as their ->atomic_check()
+ * callback.
+ *
+ * This just wraps the two parts of the state checking for planes and modeset
+ * state in the default order: First it calls drm_atomic_helper_check_modeset()
+ * and then drm_atomic_helper_check_planes(). The assumption is that the
+ * ->atomic_check functions depend upon an updated adjusted_mode.clock to
+ * e.g. properly compute watermarks.
+ *
+ * RETURNS
+ * Zero for success or -errno
+ */
+int drm_atomic_helper_check(struct drm_device *dev,
+			    struct drm_atomic_state *state)
+{
+	int ret;
+
+	ret = drm_atomic_helper_check_modeset(dev, state);
+	if (ret)
+		return ret;
+
+	ret = drm_atomic_helper_check_planes(dev, state);
+	if (ret)
+		return ret;
+
+	return ret;
+}
+EXPORT_SYMBOL(drm_atomic_helper_check);
+
+static void
+disable_outputs(struct drm_device *dev, struct drm_atomic_state *old_state)
+{
+	struct drm_connector *connector;
+	struct drm_connector_state *old_conn_state;
+	struct drm_crtc *crtc;
+	struct drm_crtc_state *old_crtc_state;
+	int i;
+
+	for_each_connector_in_state(old_state, connector, old_conn_state, i) {
+		const struct drm_encoder_helper_funcs *funcs;
+		struct drm_encoder *encoder;
+
+		/* Shut down everything that's in the changeset and currently
+		 * still on. So need to check the old, saved state. */
+		if (!old_conn_state->crtc)
+			continue;
+
+		old_crtc_state = drm_atomic_get_existing_crtc_state(old_state,
+								    old_conn_state->crtc);
+
+		if (!old_crtc_state->active ||
+		    !drm_atomic_crtc_needs_modeset(old_conn_state->crtc->state))
+			continue;
+
+		encoder = old_conn_state->best_encoder;
+
+		/* We shouldn't get this far if we didn't previously have
+		 * an encoder.. but WARN_ON() rather than explode.
+		 */
+		if (WARN_ON(!encoder))
+			continue;
+
+		funcs = encoder->helper_private;
+
+		DRM_DEBUG_ATOMIC("disabling [ENCODER:%d:%s]\n",
+				 encoder->base.id, encoder->name);
+
+		/*
+		 * Each encoder has at most one connector (since we always steal
+		 * it away), so we won't call disable hooks twice.
+		 */
+		drm_bridge_disable(encoder->bridge);
+
+		/* Right function depends upon target state. */
+		if (funcs) {
+			if (connector->state->crtc && funcs->prepare)
+				funcs->prepare(encoder);
+			else if (funcs->disable)
+				funcs->disable(encoder);
+			else if (funcs->dpms)
+				funcs->dpms(encoder, DRM_MODE_DPMS_OFF);
+		}
+
+		drm_bridge_post_disable(encoder->bridge);
+	}
+
+	for_each_crtc_in_state(old_state, crtc, old_crtc_state, i) {
+		const struct drm_crtc_helper_funcs *funcs;
+
+		/* Shut down everything that needs a full modeset. */
+		if (!drm_atomic_crtc_needs_modeset(crtc->state))
+			continue;
+
+		if (!old_crtc_state->active)
+			continue;
+
+		funcs = crtc->helper_private;
+
+		DRM_DEBUG_ATOMIC("disabling [CRTC:%d:%s]\n",
+				 crtc->base.id, crtc->name);
+
+
+		/* Right function depends upon target state. */
+		if (crtc->state->enable && funcs->prepare)
+			funcs->prepare(crtc);
+		else if (funcs->disable)
+			funcs->disable(crtc);
+		else
+			funcs->dpms(crtc, DRM_MODE_DPMS_OFF);
+	}
+}
+
+/**
+ * drm_atomic_helper_update_legacy_modeset_state - update legacy modeset state
+ * @dev: DRM device
+ * @old_state: atomic state object with old state structures
+ *
+ * This function updates all the various legacy modeset state pointers in
+ * connectors, encoders and crtcs. It also updates the timestamping constants
+ * used for precise vblank timestamps by calling
+ * drm_calc_timestamping_constants().
+ *
+ * Drivers can use this for building their own atomic commit if they don't have
+ * a pure helper-based modeset implementation.
+ */
+void
+drm_atomic_helper_update_legacy_modeset_state(struct drm_device *dev,
+					      struct drm_atomic_state *old_state)
+{
+	struct drm_connector *connector;
+	struct drm_connector_state *old_conn_state;
+	struct drm_crtc *crtc;
+	struct drm_crtc_state *old_crtc_state;
+	int i;
+
+	/* clear out existing links and update dpms */
+	for_each_connector_in_state(old_state, connector, old_conn_state, i) {
+		if (connector->encoder) {
+			WARN_ON(!connector->encoder->crtc);
+
+			connector->encoder->crtc = NULL;
+			connector->encoder = NULL;
+		}
+
+		crtc = connector->state->crtc;
+		if ((!crtc && old_conn_state->crtc) ||
+		    (crtc && drm_atomic_crtc_needs_modeset(crtc->state))) {
+			struct drm_property *dpms_prop =
+				dev->mode_config.dpms_property;
+			int mode = DRM_MODE_DPMS_OFF;
+
+			if (crtc && crtc->state->active)
+				mode = DRM_MODE_DPMS_ON;
+
+			connector->dpms = mode;
+			drm_object_property_set_value(&connector->base,
+						      dpms_prop, mode);
+		}
+	}
+
+	/* set new links */
+	for_each_connector_in_state(old_state, connector, old_conn_state, i) {
+		if (!connector->state->crtc)
+			continue;
+
+		if (WARN_ON(!connector->state->best_encoder))
+			continue;
+
+		connector->encoder = connector->state->best_encoder;
+		connector->encoder->crtc = connector->state->crtc;
+	}
+
+	/* set legacy state in the crtc structure */
+	for_each_crtc_in_state(old_state, crtc, old_crtc_state, i) {
+		struct drm_plane *primary = crtc->primary;
+
+		crtc->mode = crtc->state->mode;
+		crtc->enabled = crtc->state->enable;
+
+		if (drm_atomic_get_existing_plane_state(old_state, primary) &&
+		    primary->state->crtc == crtc) {
+			crtc->x = primary->state->src_x >> 16;
+			crtc->y = primary->state->src_y >> 16;
+		}
+
+		if (crtc->state->enable)
+			drm_calc_timestamping_constants(crtc,
+							&crtc->state->adjusted_mode);
+	}
+}
+EXPORT_SYMBOL(drm_atomic_helper_update_legacy_modeset_state);
+
+static void
+crtc_set_mode(struct drm_device *dev, struct drm_atomic_state *old_state)
+{
+	struct drm_crtc *crtc;
+	struct drm_crtc_state *old_crtc_state;
+	struct drm_connector *connector;
+	struct drm_connector_state *old_conn_state;
+	int i;
+
+	for_each_crtc_in_state(old_state, crtc, old_crtc_state, i) {
+		const struct drm_crtc_helper_funcs *funcs;
+
+		if (!crtc->state->mode_changed)
+			continue;
+
+		funcs = crtc->helper_private;
+
+		if (crtc->state->enable && funcs->mode_set_nofb) {
+			DRM_DEBUG_ATOMIC("modeset on [CRTC:%d:%s]\n",
+					 crtc->base.id, crtc->name);
+
+			funcs->mode_set_nofb(crtc);
+		}
+	}
+
+	for_each_connector_in_state(old_state, connector, old_conn_state, i) {
+		const struct drm_encoder_helper_funcs *funcs;
+		struct drm_crtc_state *new_crtc_state;
+		struct drm_encoder *encoder;
+		struct drm_display_mode *mode, *adjusted_mode;
+
+		if (!connector->state->best_encoder)
+			continue;
+
+		encoder = connector->state->best_encoder;
+		funcs = encoder->helper_private;
+		new_crtc_state = connector->state->crtc->state;
+		mode = &new_crtc_state->mode;
+		adjusted_mode = &new_crtc_state->adjusted_mode;
+
+		if (!new_crtc_state->mode_changed)
+			continue;
+
+		DRM_DEBUG_ATOMIC("modeset on [ENCODER:%d:%s]\n",
+				 encoder->base.id, encoder->name);
+
+		/*
+		 * Each encoder has at most one connector (since we always steal
+		 * it away), so we won't call mode_set hooks twice.
+		 */
+		if (funcs && funcs->mode_set)
+			funcs->mode_set(encoder, mode, adjusted_mode);
+
+		drm_bridge_mode_set(encoder->bridge, mode, adjusted_mode);
+	}
+}
+
+/**
+ * drm_atomic_helper_commit_modeset_disables - modeset commit to disable outputs
+ * @dev: DRM device
+ * @old_state: atomic state object with old state structures
+ *
+ * This function shuts down all the outputs that need to be shut down and
+ * prepares them (if required) with the new mode.
+ *
+ * For compatibility with legacy crtc helpers this should be called before
+ * drm_atomic_helper_commit_planes(), which is what the default commit function
+ * does. But drivers with different needs can group the modeset commits together
+ * and do the plane commits at the end. This is useful for drivers doing runtime
+ * PM since planes updates then only happen when the CRTC is actually enabled.
+ */
+void drm_atomic_helper_commit_modeset_disables(struct drm_device *dev,
+					       struct drm_atomic_state *old_state)
+{
+	disable_outputs(dev, old_state);
+
+	drm_atomic_helper_update_legacy_modeset_state(dev, old_state);
+
+	crtc_set_mode(dev, old_state);
+}
+EXPORT_SYMBOL(drm_atomic_helper_commit_modeset_disables);
+
+/**
+ * drm_atomic_helper_commit_modeset_enables - modeset commit to enable outputs
+ * @dev: DRM device
+ * @old_state: atomic state object with old state structures
+ *
+ * This function enables all the outputs with the new configuration which had to
+ * be turned off for the update.
+ *
+ * For compatibility with legacy crtc helpers this should be called after
+ * drm_atomic_helper_commit_planes(), which is what the default commit function
+ * does. But drivers with different needs can group the modeset commits together
+ * and do the plane commits at the end. This is useful for drivers doing runtime
+ * PM since planes updates then only happen when the CRTC is actually enabled.
+ */
+void drm_atomic_helper_commit_modeset_enables(struct drm_device *dev,
+					      struct drm_atomic_state *old_state)
+{
+	struct drm_crtc *crtc;
+	struct drm_crtc_state *old_crtc_state;
+	struct drm_connector *connector;
+	struct drm_connector_state *old_conn_state;
+	int i;
+
+	for_each_crtc_in_state(old_state, crtc, old_crtc_state, i) {
+		const struct drm_crtc_helper_funcs *funcs;
+
+		/* Need to filter out CRTCs where only planes change. */
+		if (!drm_atomic_crtc_needs_modeset(crtc->state))
+			continue;
+
+		if (!crtc->state->active)
+			continue;
+
+		funcs = crtc->helper_private;
+
+		if (crtc->state->enable) {
+			DRM_DEBUG_ATOMIC("enabling [CRTC:%d:%s]\n",
+					 crtc->base.id, crtc->name);
+
+			if (funcs->enable)
+				funcs->enable(crtc);
+			else
+				funcs->commit(crtc);
+		}
+	}
+
+	for_each_connector_in_state(old_state, connector, old_conn_state, i) {
+		const struct drm_encoder_helper_funcs *funcs;
+		struct drm_encoder *encoder;
+
+		if (!connector->state->best_encoder)
+			continue;
+
+		if (!connector->state->crtc->state->active ||
+		    !drm_atomic_crtc_needs_modeset(connector->state->crtc->state))
+			continue;
+
+		encoder = connector->state->best_encoder;
+		funcs = encoder->helper_private;
+
+		DRM_DEBUG_ATOMIC("enabling [ENCODER:%d:%s]\n",
+				 encoder->base.id, encoder->name);
+
+		/*
+		 * Each encoder has at most one connector (since we always steal
+		 * it away), so we won't call enable hooks twice.
+		 */
+		drm_bridge_pre_enable(encoder->bridge);
+
+		if (funcs) {
+			if (funcs->enable)
+				funcs->enable(encoder);
+			else if (funcs->commit)
+				funcs->commit(encoder);
+		}
+
+		drm_bridge_enable(encoder->bridge);
+	}
+}
+EXPORT_SYMBOL(drm_atomic_helper_commit_modeset_enables);
+
+/**
+ * drm_atomic_helper_wait_for_fences - wait for fences stashed in plane state
+ * @dev: DRM device
+ * @state: atomic state object with old state structures
+ *
+ * For implicit sync, driver should fish the exclusive fence out from the
+ * incoming fb's and stash it in the drm_plane_state.  This is called after
+ * drm_atomic_helper_swap_state() so it uses the current plane state (and
+ * just uses the atomic state to find the changed planes)
+ */
+void drm_atomic_helper_wait_for_fences(struct drm_device *dev,
+			    struct drm_atomic_state *state)
+{
+	struct drm_plane *plane;
+	struct drm_plane_state *plane_state;
+	int i;
+
+	for_each_plane_in_state(state, plane, plane_state, i) {
+		if (!plane->state->fence)
+			continue;
+
+		WARN_ON(!plane->state->fb);
+
+		fence_wait(plane->state->fence, false);
+		fence_put(plane->state->fence);
+		plane->state->fence = NULL;
+	}
+}
+EXPORT_SYMBOL(drm_atomic_helper_wait_for_fences);
+
+/**
+ * drm_atomic_helper_framebuffer_changed - check if framebuffer has changed
+ * @dev: DRM device
+ * @old_state: atomic state object with old state structures
+ * @crtc: DRM crtc
+ *
+ * Checks whether the framebuffer used for this CRTC changes as a result of
+ * the atomic update.  This is useful for drivers which cannot use
+ * drm_atomic_helper_wait_for_vblanks() and need to reimplement its
+ * functionality.
+ *
+ * Returns:
+ * true if the framebuffer changed.
+ */
+bool drm_atomic_helper_framebuffer_changed(struct drm_device *dev,
+					   struct drm_atomic_state *old_state,
+					   struct drm_crtc *crtc)
+{
+	struct drm_plane *plane;
+	struct drm_plane_state *old_plane_state;
+	int i;
+
+	for_each_plane_in_state(old_state, plane, old_plane_state, i) {
+		if (plane->state->crtc != crtc &&
+		    old_plane_state->crtc != crtc)
+			continue;
+
+		if (plane->state->fb != old_plane_state->fb)
+			return true;
+	}
+
+	return false;
+}
+EXPORT_SYMBOL(drm_atomic_helper_framebuffer_changed);
+
+/**
+ * drm_atomic_helper_wait_for_vblanks - wait for vblank on crtcs
+ * @dev: DRM device
+ * @old_state: atomic state object with old state structures
+ *
+ * Helper to, after atomic commit, wait for vblanks on all effected
+ * crtcs (ie. before cleaning up old framebuffers using
+ * drm_atomic_helper_cleanup_planes()). It will only wait on crtcs where the
+ * framebuffers have actually changed to optimize for the legacy cursor and
+ * plane update use-case.
+ */
+void
+drm_atomic_helper_wait_for_vblanks(struct drm_device *dev,
+		struct drm_atomic_state *old_state)
+{
+	struct drm_crtc *crtc;
+	struct drm_crtc_state *old_crtc_state;
+	int i, ret;
+
+	for_each_crtc_in_state(old_state, crtc, old_crtc_state, i) {
+		/* No one cares about the old state, so abuse it for tracking
+		 * and store whether we hold a vblank reference (and should do a
+		 * vblank wait) in the ->enable boolean. */
+		old_crtc_state->enable = false;
+
+		if (!crtc->state->enable)
+			continue;
+
+		/* Legacy cursor ioctls are completely unsynced, and userspace
+		 * relies on that (by doing tons of cursor updates). */
+		if (old_state->legacy_cursor_update)
+			continue;
+
+		if (!drm_atomic_helper_framebuffer_changed(dev,
+				old_state, crtc))
+			continue;
+
+		ret = drm_crtc_vblank_get(crtc);
+		if (ret != 0)
+			continue;
+
+		old_crtc_state->enable = true;
+		old_crtc_state->last_vblank_count = drm_crtc_vblank_count(crtc);
+	}
+
+	for_each_crtc_in_state(old_state, crtc, old_crtc_state, i) {
+		if (!old_crtc_state->enable)
+			continue;
+
+		ret = wait_event_timeout(dev->vblank[i].queue,
+				old_crtc_state->last_vblank_count !=
+					drm_crtc_vblank_count(crtc),
+				msecs_to_jiffies(50));
+
+		WARN(!ret, "[CRTC:%d] vblank wait timed out\n", crtc->base.id);
+
+		drm_crtc_vblank_put(crtc);
+	}
+}
+EXPORT_SYMBOL(drm_atomic_helper_wait_for_vblanks);
+
+/**
+ * drm_atomic_helper_commit - commit validated state object
+ * @dev: DRM device
+ * @state: the driver state object
+ * @nonblocking: whether nonblocking behavior is requested.
+ *
+ * This function commits a with drm_atomic_helper_check() pre-validated state
+ * object. This can still fail when e.g. the framebuffer reservation fails. For
+ * now this doesn't implement nonblocking commits.
+ *
+ * Note that right now this function does not support nonblocking commits, hence
+ * driver writers must implement their own version for now. Also note that the
+ * default ordering of how the various stages are called is to match the legacy
+ * modeset helper library closest. One peculiarity of that is that it doesn't
+ * mesh well with runtime PM at all.
+ *
+ * For drivers supporting runtime PM the recommended sequence is
+ *
+ *     drm_atomic_helper_commit_modeset_disables(dev, state);
+ *
+ *     drm_atomic_helper_commit_modeset_enables(dev, state);
+ *
+ *     drm_atomic_helper_commit_planes(dev, state, true);
+ *
+ * See the kerneldoc entries for these three functions for more details.
+ *
+ * RETURNS
+ * Zero for success or -errno.
+ */
+int drm_atomic_helper_commit(struct drm_device *dev,
+			     struct drm_atomic_state *state,
+			     bool nonblock)
+{
+	int ret;
+
+	if (nonblock)
+		return -EBUSY;
+
+	ret = drm_atomic_helper_prepare_planes(dev, state);
+	if (ret)
+		return ret;
+
+	/*
+	 * This is the point of no return - everything below never fails except
+	 * when the hw goes bonghits. Which means we can commit the new state on
+	 * the software side now.
+	 */
+
+	drm_atomic_helper_swap_state(dev, state);
+
+	/*
+	 * Everything below can be run asynchronously without the need to grab
+	 * any modeset locks at all under one condition: It must be guaranteed
+	 * that the asynchronous work has either been cancelled (if the driver
+	 * supports it, which at least requires that the framebuffers get
+	 * cleaned up with drm_atomic_helper_cleanup_planes()) or completed
+	 * before the new state gets committed on the software side with
+	 * drm_atomic_helper_swap_state().
+	 *
+	 * This scheme allows new atomic state updates to be prepared and
+	 * checked in parallel to the asynchronous completion of the previous
+	 * update. Which is important since compositors need to figure out the
+	 * composition of the next frame right after having submitted the
+	 * current layout.
+	 */
+
+	drm_atomic_helper_wait_for_fences(dev, state);
+
+	drm_atomic_helper_commit_modeset_disables(dev, state);
+
+	drm_atomic_helper_commit_planes(dev, state, false);
+
+	drm_atomic_helper_commit_modeset_enables(dev, state);
+
+	drm_atomic_helper_wait_for_vblanks(dev, state);
+
+	drm_atomic_helper_cleanup_planes(dev, state);
+
+	drm_atomic_state_free(state);
+
+	return 0;
+}
+EXPORT_SYMBOL(drm_atomic_helper_commit);
+
+/**
+ * DOC: implementing nonblocking commit
+ *
+ * For now the atomic helpers don't support nonblocking commit directly. If
+ * there is real need it could be added though, using the dma-buf fence
+ * infrastructure for generic synchronization with outstanding rendering.
+ *
+ * For now drivers have to implement nonblocking commit themselves, with the
+ * following sequence being the recommended one:
+ *
+ * 1. Run drm_atomic_helper_prepare_planes() first. This is the only function
+ * which commit needs to call which can fail, so we want to run it first and
+ * synchronously.
+ *
+ * 2. Synchronize with any outstanding nonblocking commit worker threads which
+ * might be affected the new state update. This can be done by either cancelling
+ * or flushing the work items, depending upon whether the driver can deal with
+ * cancelled updates. Note that it is important to ensure that the framebuffer
+ * cleanup is still done when cancelling.
+ *
+ * For sufficient parallelism it is recommended to have a work item per crtc
+ * (for updates which don't touch global state) and a global one. Then we only
+ * need to synchronize with the crtc work items for changed crtcs and the global
+ * work item, which allows nice concurrent updates on disjoint sets of crtcs.
+ *
+ * 3. The software state is updated synchronously with
+ * drm_atomic_helper_swap_state(). Doing this under the protection of all modeset
+ * locks means concurrent callers never see inconsistent state. And doing this
+ * while it's guaranteed that no relevant nonblocking worker runs means that
+ * nonblocking workers do not need grab any locks. Actually they must not grab
+ * locks, for otherwise the work flushing will deadlock.
+ *
+ * 4. Schedule a work item to do all subsequent steps, using the split-out
+ * commit helpers: a) pre-plane commit b) plane commit c) post-plane commit and
+ * then cleaning up the framebuffers after the old framebuffer is no longer
+ * being displayed.
+ */
+
+/**
+ * drm_atomic_helper_prepare_planes - prepare plane resources before commit
+ * @dev: DRM device
+ * @state: atomic state object with new state structures
+ *
+ * This function prepares plane state, specifically framebuffers, for the new
+ * configuration. If any failure is encountered this function will call
+ * ->cleanup_fb on any already successfully prepared framebuffer.
+ *
+ * Returns:
+ * 0 on success, negative error code on failure.
+ */
+int drm_atomic_helper_prepare_planes(struct drm_device *dev,
+				     struct drm_atomic_state *state)
+{
+	int nplanes = dev->mode_config.num_total_plane;
+	int ret, i;
+
+	for (i = 0; i < nplanes; i++) {
+		const struct drm_plane_helper_funcs *funcs;
+		struct drm_plane *plane = state->planes[i];
+		struct drm_plane_state *plane_state = state->plane_states[i];
+
+		if (!plane)
+			continue;
+
+		funcs = plane->helper_private;
+
+		if (funcs->prepare_fb) {
+			ret = funcs->prepare_fb(plane, plane_state);
+			if (ret)
+				goto fail;
+		}
+	}
+
+	return 0;
+
+fail:
+	for (i--; i >= 0; i--) {
+		const struct drm_plane_helper_funcs *funcs;
+		struct drm_plane *plane = state->planes[i];
+		struct drm_plane_state *plane_state = state->plane_states[i];
+
+		if (!plane)
+			continue;
+
+		funcs = plane->helper_private;
+
+		if (funcs->cleanup_fb)
+			funcs->cleanup_fb(plane, plane_state);
+
+	}
+
+	return ret;
+}
+EXPORT_SYMBOL(drm_atomic_helper_prepare_planes);
+
+bool plane_crtc_active(struct drm_plane_state *state)
+{
+	return state->crtc && state->crtc->state->active;
+}
+
+/**
+ * drm_atomic_helper_commit_planes - commit plane state
+ * @dev: DRM device
+ * @old_state: atomic state object with old state structures
+ * @active_only: Only commit on active CRTC if set
+ *
+ * This function commits the new plane state using the plane and atomic helper
+ * functions for planes and crtcs. It assumes that the atomic state has already
+ * been pushed into the relevant object state pointers, since this step can no
+ * longer fail.
+ *
+ * It still requires the global state object @old_state to know which planes and
+ * crtcs need to be updated though.
+ *
+ * Note that this function does all plane updates across all CRTCs in one step.
+ * If the hardware can't support this approach look at
+ * drm_atomic_helper_commit_planes_on_crtc() instead.
+ *
+ * Plane parameters can be updated by applications while the associated CRTC is
+ * disabled. The DRM/KMS core will store the parameters in the plane state,
+ * which will be available to the driver when the CRTC is turned on. As a result
+ * most drivers don't need to be immediately notified of plane updates for a
+ * disabled CRTC.
+ *
+ * Unless otherwise needed, drivers are advised to set the @active_only
+ * parameters to true in order not to receive plane update notifications related
+ * to a disabled CRTC. This avoids the need to manually ignore plane updates in
+ * driver code when the driver and/or hardware can't or just don't need to deal
+ * with updates on disabled CRTCs, for example when supporting runtime PM.
+ *
+ * The drm_atomic_helper_commit() default implementation only sets @active_only
+ * to false to most closely match the behaviour of the legacy helpers. This should
+ * not be copied blindly by drivers.
+ */
+void drm_atomic_helper_commit_planes(struct drm_device *dev,
+				     struct drm_atomic_state *old_state,
+				     bool active_only)
+{
+	struct drm_crtc *crtc;
+	struct drm_crtc_state *old_crtc_state;
+	struct drm_plane *plane;
+	struct drm_plane_state *old_plane_state;
+	int i;
+
+	for_each_crtc_in_state(old_state, crtc, old_crtc_state, i) {
+		const struct drm_crtc_helper_funcs *funcs;
+
+		funcs = crtc->helper_private;
+
+		if (!funcs || !funcs->atomic_begin)
+			continue;
+
+		if (active_only && !crtc->state->active)
+			continue;
+
+		funcs->atomic_begin(crtc, old_crtc_state);
+	}
+
+	for_each_plane_in_state(old_state, plane, old_plane_state, i) {
+		const struct drm_plane_helper_funcs *funcs;
+		bool disabling;
+
+		funcs = plane->helper_private;
+
+		if (!funcs)
+			continue;
+
+		disabling = drm_atomic_plane_disabling(plane, old_plane_state);
+
+		if (active_only) {
+			/*
+			 * Skip planes related to inactive CRTCs. If the plane
+			 * is enabled use the state of the current CRTC. If the
+			 * plane is being disabled use the state of the old
+			 * CRTC to avoid skipping planes being disabled on an
+			 * active CRTC.
+			 */
+			if (!disabling && !plane_crtc_active(plane->state))
+				continue;
+			if (disabling && !plane_crtc_active(old_plane_state))
+				continue;
+		}
+
+		/*
+		 * Special-case disabling the plane if drivers support it.
+		 */
+		if (disabling && funcs->atomic_disable)
+			funcs->atomic_disable(plane, old_plane_state);
+		else if (plane->state->crtc || disabling)
+			funcs->atomic_update(plane, old_plane_state);
+	}
+
+	for_each_crtc_in_state(old_state, crtc, old_crtc_state, i) {
+		const struct drm_crtc_helper_funcs *funcs;
+
+		funcs = crtc->helper_private;
+
+		if (!funcs || !funcs->atomic_flush)
+			continue;
+
+		if (active_only && !crtc->state->active)
+			continue;
+
+		funcs->atomic_flush(crtc, old_crtc_state);
+	}
+}
+EXPORT_SYMBOL(drm_atomic_helper_commit_planes);
+
+/**
+ * drm_atomic_helper_commit_planes_on_crtc - commit plane state for a crtc
+ * @old_crtc_state: atomic state object with the old crtc state
+ *
+ * This function commits the new plane state using the plane and atomic helper
+ * functions for planes on the specific crtc. It assumes that the atomic state
+ * has already been pushed into the relevant object state pointers, since this
+ * step can no longer fail.
+ *
+ * This function is useful when plane updates should be done crtc-by-crtc
+ * instead of one global step like drm_atomic_helper_commit_planes() does.
+ *
+ * This function can only be savely used when planes are not allowed to move
+ * between different CRTCs because this function doesn't handle inter-CRTC
+ * depencies. Callers need to ensure that either no such depencies exist,
+ * resolve them through ordering of commit calls or through some other means.
+ */
+void
+drm_atomic_helper_commit_planes_on_crtc(struct drm_crtc_state *old_crtc_state)
+{
+	const struct drm_crtc_helper_funcs *crtc_funcs;
+	struct drm_crtc *crtc = old_crtc_state->crtc;
+	struct drm_atomic_state *old_state = old_crtc_state->state;
+	struct drm_plane *plane;
+	unsigned plane_mask;
+
+	plane_mask = old_crtc_state->plane_mask;
+	plane_mask |= crtc->state->plane_mask;
+
+	crtc_funcs = crtc->helper_private;
+	if (crtc_funcs && crtc_funcs->atomic_begin)
+		crtc_funcs->atomic_begin(crtc, old_crtc_state);
+
+	drm_for_each_plane_mask(plane, crtc->dev, plane_mask) {
+		struct drm_plane_state *old_plane_state =
+			drm_atomic_get_existing_plane_state(old_state, plane);
+		const struct drm_plane_helper_funcs *plane_funcs;
+
+		plane_funcs = plane->helper_private;
+
+		if (!old_plane_state || !plane_funcs)
+			continue;
+
+		WARN_ON(plane->state->crtc && plane->state->crtc != crtc);
+
+		if (drm_atomic_plane_disabling(plane, old_plane_state) &&
+		    plane_funcs->atomic_disable)
+			plane_funcs->atomic_disable(plane, old_plane_state);
+		else if (plane->state->crtc ||
+			 drm_atomic_plane_disabling(plane, old_plane_state))
+			plane_funcs->atomic_update(plane, old_plane_state);
+	}
+
+	if (crtc_funcs && crtc_funcs->atomic_flush)
+		crtc_funcs->atomic_flush(crtc, old_crtc_state);
+}
+EXPORT_SYMBOL(drm_atomic_helper_commit_planes_on_crtc);
+
+/**
+ * drm_atomic_helper_disable_planes_on_crtc - helper to disable CRTC's planes
+ * @crtc: CRTC
+ * @atomic: if set, synchronize with CRTC's atomic_begin/flush hooks
+ *
+ * Disables all planes associated with the given CRTC. This can be
+ * used for instance in the CRTC helper disable callback to disable
+ * all planes before shutting down the display pipeline.
+ *
+ * If the atomic-parameter is set the function calls the CRTC's
+ * atomic_begin hook before and atomic_flush hook after disabling the
+ * planes.
+ *
+ * It is a bug to call this function without having implemented the
+ * ->atomic_disable() plane hook.
+ */
+void drm_atomic_helper_disable_planes_on_crtc(struct drm_crtc *crtc,
+					      bool atomic)
+{
+	const struct drm_crtc_helper_funcs *crtc_funcs =
+		crtc->helper_private;
+	struct drm_plane *plane;
+
+	if (atomic && crtc_funcs && crtc_funcs->atomic_begin)
+		crtc_funcs->atomic_begin(crtc, NULL);
+
+	drm_for_each_plane(plane, crtc->dev) {
+		const struct drm_plane_helper_funcs *plane_funcs =
+			plane->helper_private;
+
+		if (plane->state->crtc != crtc || !plane_funcs)
+			continue;
+
+		WARN_ON(!plane_funcs->atomic_disable);
+		if (plane_funcs->atomic_disable)
+			plane_funcs->atomic_disable(plane, NULL);
+	}
+
+	if (atomic && crtc_funcs && crtc_funcs->atomic_flush)
+		crtc_funcs->atomic_flush(crtc, NULL);
+}
+EXPORT_SYMBOL(drm_atomic_helper_disable_planes_on_crtc);
+
+/**
+ * drm_atomic_helper_cleanup_planes - cleanup plane resources after commit
+ * @dev: DRM device
+ * @old_state: atomic state object with old state structures
+ *
+ * This function cleans up plane state, specifically framebuffers, from the old
+ * configuration. Hence the old configuration must be perserved in @old_state to
+ * be able to call this function.
+ *
+ * This function must also be called on the new state when the atomic update
+ * fails at any point after calling drm_atomic_helper_prepare_planes().
+ */
+void drm_atomic_helper_cleanup_planes(struct drm_device *dev,
+				      struct drm_atomic_state *old_state)
+{
+	struct drm_plane *plane;
+	struct drm_plane_state *plane_state;
+	int i;
+
+	for_each_plane_in_state(old_state, plane, plane_state, i) {
+		const struct drm_plane_helper_funcs *funcs;
+
+		funcs = plane->helper_private;
+
+		if (funcs->cleanup_fb)
+			funcs->cleanup_fb(plane, plane_state);
+	}
+}
+EXPORT_SYMBOL(drm_atomic_helper_cleanup_planes);
+
+/**
+ * drm_atomic_helper_swap_state - store atomic state into current sw state
+ * @dev: DRM device
+ * @state: atomic state
+ *
+ * This function stores the atomic state into the current state pointers in all
+ * driver objects. It should be called after all failing steps have been done
+ * and succeeded, but before the actual hardware state is committed.
+ *
+ * For cleanup and error recovery the current state for all changed objects will
+ * be swaped into @state.
+ *
+ * With that sequence it fits perfectly into the plane prepare/cleanup sequence:
+ *
+ * 1. Call drm_atomic_helper_prepare_planes() with the staged atomic state.
+ *
+ * 2. Do any other steps that might fail.
+ *
+ * 3. Put the staged state into the current state pointers with this function.
+ *
+ * 4. Actually commit the hardware state.
+ *
+ * 5. Call drm_atomic_helper_cleanup_planes() with @state, which since step 3
+ * contains the old state. Also do any other cleanup required with that state.
+ */
+void drm_atomic_helper_swap_state(struct drm_device *dev,
+				  struct drm_atomic_state *state)
+{
+	int i;
+
+	for (i = 0; i < state->num_connector; i++) {
+		struct drm_connector *connector = state->connectors[i];
+
+		if (!connector)
+			continue;
+
+		connector->state->state = state;
+		swap(state->connector_states[i], connector->state);
+		connector->state->state = NULL;
+	}
+
+	for (i = 0; i < dev->mode_config.num_crtc; i++) {
+		struct drm_crtc *crtc = state->crtcs[i];
+
+		if (!crtc)
+			continue;
+
+		crtc->state->state = state;
+		swap(state->crtc_states[i], crtc->state);
+		crtc->state->state = NULL;
+	}
+
+	for (i = 0; i < dev->mode_config.num_total_plane; i++) {
+		struct drm_plane *plane = state->planes[i];
+
+		if (!plane)
+			continue;
+
+		plane->state->state = state;
+		swap(state->plane_states[i], plane->state);
+		plane->state->state = NULL;
+	}
+}
+EXPORT_SYMBOL(drm_atomic_helper_swap_state);
+
+/**
+ * drm_atomic_helper_update_plane - Helper for primary plane update using atomic
+ * @plane: plane object to update
+ * @crtc: owning CRTC of owning plane
+ * @fb: framebuffer to flip onto plane
+ * @crtc_x: x offset of primary plane on crtc
+ * @crtc_y: y offset of primary plane on crtc
+ * @crtc_w: width of primary plane rectangle on crtc
+ * @crtc_h: height of primary plane rectangle on crtc
+ * @src_x: x offset of @fb for panning
+ * @src_y: y offset of @fb for panning
+ * @src_w: width of source rectangle in @fb
+ * @src_h: height of source rectangle in @fb
+ *
+ * Provides a default plane update handler using the atomic driver interface.
+ *
+ * RETURNS:
+ * Zero on success, error code on failure
+ */
+int drm_atomic_helper_update_plane(struct drm_plane *plane,
+				   struct drm_crtc *crtc,
+				   struct drm_framebuffer *fb,
+				   int crtc_x, int crtc_y,
+				   unsigned int crtc_w, unsigned int crtc_h,
+				   uint32_t src_x, uint32_t src_y,
+				   uint32_t src_w, uint32_t src_h)
+{
+	struct drm_atomic_state *state;
+	struct drm_plane_state *plane_state;
+	int ret = 0;
+
+	state = drm_atomic_state_alloc(plane->dev);
+	if (!state)
+		return -ENOMEM;
+
+	state->acquire_ctx = drm_modeset_legacy_acquire_ctx(crtc);
+retry:
+	plane_state = drm_atomic_get_plane_state(state, plane);
+	if (IS_ERR(plane_state)) {
+		ret = PTR_ERR(plane_state);
+		goto fail;
+	}
+
+	ret = drm_atomic_set_crtc_for_plane(plane_state, crtc);
+	if (ret != 0)
+		goto fail;
+	drm_atomic_set_fb_for_plane(plane_state, fb);
+	plane_state->crtc_x = crtc_x;
+	plane_state->crtc_y = crtc_y;
+	plane_state->crtc_w = crtc_w;
+	plane_state->crtc_h = crtc_h;
+	plane_state->src_x = src_x;
+	plane_state->src_y = src_y;
+	plane_state->src_w = src_w;
+	plane_state->src_h = src_h;
+
+	if (plane == crtc->cursor)
+		state->legacy_cursor_update = true;
+
+	ret = drm_atomic_commit(state);
+	if (ret != 0)
+		goto fail;
+
+	/* Driver takes ownership of state on successful commit. */
+	return 0;
+fail:
+	if (ret == -EDEADLK)
+		goto backoff;
+
+	drm_atomic_state_free(state);
+
+	return ret;
+backoff:
+	drm_atomic_state_clear(state);
+	drm_atomic_legacy_backoff(state);
+
+	/*
+	 * Someone might have exchanged the framebuffer while we dropped locks
+	 * in the backoff code. We need to fix up the fb refcount tracking the
+	 * core does for us.
+	 */
+	plane->old_fb = plane->fb;
+
+	goto retry;
+}
+EXPORT_SYMBOL(drm_atomic_helper_update_plane);
+
+/**
+ * drm_atomic_helper_disable_plane - Helper for primary plane disable using * atomic
+ * @plane: plane to disable
+ *
+ * Provides a default plane disable handler using the atomic driver interface.
+ *
+ * RETURNS:
+ * Zero on success, error code on failure
+ */
+int drm_atomic_helper_disable_plane(struct drm_plane *plane)
+{
+	struct drm_atomic_state *state;
+	struct drm_plane_state *plane_state;
+	int ret = 0;
+
+	/*
+	 * FIXME: Without plane->crtc set we can't get at the implicit legacy
+	 * acquire context. The real fix will be to wire the acquire ctx through
+	 * everywhere we need it, but meanwhile prevent chaos by just skipping
+	 * this noop. The critical case is the cursor ioctls which a) only grab
+	 * crtc/cursor-plane locks (so we need the crtc to get at the right
+	 * acquire context) and b) can try to disable the plane multiple times.
+	 */
+	if (!plane->crtc)
+		return 0;
+
+	state = drm_atomic_state_alloc(plane->dev);
+	if (!state)
+		return -ENOMEM;
+
+	state->acquire_ctx = drm_modeset_legacy_acquire_ctx(plane->crtc);
+retry:
+	plane_state = drm_atomic_get_plane_state(state, plane);
+	if (IS_ERR(plane_state)) {
+		ret = PTR_ERR(plane_state);
+		goto fail;
+	}
+
+	if (plane_state->crtc && (plane == plane->crtc->cursor))
+		plane_state->state->legacy_cursor_update = true;
+
+	ret = __drm_atomic_helper_disable_plane(plane, plane_state);
+	if (ret != 0)
+		goto fail;
+
+	ret = drm_atomic_commit(state);
+	if (ret != 0)
+		goto fail;
+
+	/* Driver takes ownership of state on successful commit. */
+	return 0;
+fail:
+	if (ret == -EDEADLK)
+		goto backoff;
+
+	drm_atomic_state_free(state);
+
+	return ret;
+backoff:
+	drm_atomic_state_clear(state);
+	drm_atomic_legacy_backoff(state);
+
+	/*
+	 * Someone might have exchanged the framebuffer while we dropped locks
+	 * in the backoff code. We need to fix up the fb refcount tracking the
+	 * core does for us.
+	 */
+	plane->old_fb = plane->fb;
+
+	goto retry;
+}
+EXPORT_SYMBOL(drm_atomic_helper_disable_plane);
+
+/* just used from fb-helper and atomic-helper: */
+int __drm_atomic_helper_disable_plane(struct drm_plane *plane,
+		struct drm_plane_state *plane_state)
+{
+	int ret;
+
+	ret = drm_atomic_set_crtc_for_plane(plane_state, NULL);
+	if (ret != 0)
+		return ret;
+
+	drm_atomic_set_fb_for_plane(plane_state, NULL);
+	plane_state->crtc_x = 0;
+	plane_state->crtc_y = 0;
+	plane_state->crtc_w = 0;
+	plane_state->crtc_h = 0;
+	plane_state->src_x = 0;
+	plane_state->src_y = 0;
+	plane_state->src_w = 0;
+	plane_state->src_h = 0;
+
+	return 0;
+}
+
+static int update_output_state(struct drm_atomic_state *state,
+			       struct drm_mode_set *set)
+{
+	struct drm_device *dev = set->crtc->dev;
+	struct drm_crtc *crtc;
+	struct drm_crtc_state *crtc_state;
+	struct drm_connector *connector;
+	struct drm_connector_state *conn_state;
+	int ret, i;
+
+	ret = drm_modeset_lock(&dev->mode_config.connection_mutex,
+			       state->acquire_ctx);
+	if (ret)
+		return ret;
+
+	/* First disable all connectors on the target crtc. */
+	ret = drm_atomic_add_affected_connectors(state, set->crtc);
+	if (ret)
+		return ret;
+
+	for_each_connector_in_state(state, connector, conn_state, i) {
+		if (conn_state->crtc == set->crtc) {
+			ret = drm_atomic_set_crtc_for_connector(conn_state,
+								NULL);
+			if (ret)
+				return ret;
+		}
+	}
+
+	/* Then set all connectors from set->connectors on the target crtc */
+	for (i = 0; i < set->num_connectors; i++) {
+		conn_state = drm_atomic_get_connector_state(state,
+							    set->connectors[i]);
+		if (IS_ERR(conn_state))
+			return PTR_ERR(conn_state);
+
+		ret = drm_atomic_set_crtc_for_connector(conn_state,
+							set->crtc);
+		if (ret)
+			return ret;
+	}
+
+	for_each_crtc_in_state(state, crtc, crtc_state, i) {
+		/* Don't update ->enable for the CRTC in the set_config request,
+		 * since a mismatch would indicate a bug in the upper layers.
+		 * The actual modeset code later on will catch any
+		 * inconsistencies here. */
+		if (crtc == set->crtc)
+			continue;
+
+		if (!crtc_state->connector_mask) {
+			ret = drm_atomic_set_mode_prop_for_crtc(crtc_state,
+								NULL);
+			if (ret < 0)
+				return ret;
+
+			crtc_state->active = false;
+		}
+	}
+
+	return 0;
+}
+
+/**
+ * drm_atomic_helper_set_config - set a new config from userspace
+ * @set: mode set configuration
+ *
+ * Provides a default crtc set_config handler using the atomic driver interface.
+ *
+ * Returns:
+ * Returns 0 on success, negative errno numbers on failure.
+ */
+int drm_atomic_helper_set_config(struct drm_mode_set *set)
+{
+	struct drm_atomic_state *state;
+	struct drm_crtc *crtc = set->crtc;
+	int ret = 0;
+
+	state = drm_atomic_state_alloc(crtc->dev);
+	if (!state)
+		return -ENOMEM;
+
+	state->legacy_set_config = true;
+	state->acquire_ctx = drm_modeset_legacy_acquire_ctx(crtc);
+retry:
+	ret = __drm_atomic_helper_set_config(set, state);
+	if (ret != 0)
+		goto fail;
+
+	ret = drm_atomic_commit(state);
+	if (ret != 0)
+		goto fail;
+
+	/* Driver takes ownership of state on successful commit. */
+	return 0;
+fail:
+	if (ret == -EDEADLK)
+		goto backoff;
+
+	drm_atomic_state_free(state);
+
+	return ret;
+backoff:
+	drm_atomic_state_clear(state);
+	drm_atomic_legacy_backoff(state);
+
+	/*
+	 * Someone might have exchanged the framebuffer while we dropped locks
+	 * in the backoff code. We need to fix up the fb refcount tracking the
+	 * core does for us.
+	 */
+	crtc->primary->old_fb = crtc->primary->fb;
+
+	goto retry;
+}
+EXPORT_SYMBOL(drm_atomic_helper_set_config);
+
+/* just used from fb-helper and atomic-helper: */
+int __drm_atomic_helper_set_config(struct drm_mode_set *set,
+		struct drm_atomic_state *state)
+{
+	struct drm_crtc_state *crtc_state;
+	struct drm_plane_state *primary_state;
+	struct drm_crtc *crtc = set->crtc;
+	int hdisplay, vdisplay;
+	int ret;
+
+	crtc_state = drm_atomic_get_crtc_state(state, crtc);
+	if (IS_ERR(crtc_state))
+		return PTR_ERR(crtc_state);
+
+	primary_state = drm_atomic_get_plane_state(state, crtc->primary);
+	if (IS_ERR(primary_state))
+		return PTR_ERR(primary_state);
+
+	if (!set->mode) {
+		WARN_ON(set->fb);
+		WARN_ON(set->num_connectors);
+
+		ret = drm_atomic_set_mode_for_crtc(crtc_state, NULL);
+		if (ret != 0)
+			return ret;
+
+		crtc_state->active = false;
+
+		ret = drm_atomic_set_crtc_for_plane(primary_state, NULL);
+		if (ret != 0)
+			return ret;
+
+		drm_atomic_set_fb_for_plane(primary_state, NULL);
+
+		goto commit;
+	}
+
+	WARN_ON(!set->fb);
+	WARN_ON(!set->num_connectors);
+
+	ret = drm_atomic_set_mode_for_crtc(crtc_state, set->mode);
+	if (ret != 0)
+		return ret;
+
+	crtc_state->active = true;
+
+	ret = drm_atomic_set_crtc_for_plane(primary_state, crtc);
+	if (ret != 0)
+		return ret;
+
+	drm_crtc_get_hv_timing(set->mode, &hdisplay, &vdisplay);
+
+	drm_atomic_set_fb_for_plane(primary_state, set->fb);
+	primary_state->crtc_x = 0;
+	primary_state->crtc_y = 0;
+	primary_state->crtc_w = hdisplay;
+	primary_state->crtc_h = vdisplay;
+	primary_state->src_x = set->x << 16;
+	primary_state->src_y = set->y << 16;
+	if (primary_state->rotation & (BIT(DRM_ROTATE_90) | BIT(DRM_ROTATE_270))) {
+		primary_state->src_w = vdisplay << 16;
+		primary_state->src_h = hdisplay << 16;
+	} else {
+		primary_state->src_w = hdisplay << 16;
+		primary_state->src_h = vdisplay << 16;
+	}
+
+commit:
+	ret = update_output_state(state, set);
+	if (ret)
+		return ret;
+
+	return 0;
+}
+
+/**
+ * drm_atomic_helper_disable_all - disable all currently active outputs
+ * @dev: DRM device
+ * @ctx: lock acquisition context
+ *
+ * Loops through all connectors, finding those that aren't turned off and then
+ * turns them off by setting their DPMS mode to OFF and deactivating the CRTC
+ * that they are connected to.
+ *
+ * This is used for example in suspend/resume to disable all currently active
+ * functions when suspending.
+ *
+ * Note that if callers haven't already acquired all modeset locks this might
+ * return -EDEADLK, which must be handled by calling drm_modeset_backoff().
+ *
+ * Returns:
+ * 0 on success or a negative error code on failure.
+ *
+ * See also:
+ * drm_atomic_helper_suspend(), drm_atomic_helper_resume()
+ */
+int drm_atomic_helper_disable_all(struct drm_device *dev,
+				  struct drm_modeset_acquire_ctx *ctx)
+{
+	struct drm_atomic_state *state;
+	struct drm_connector *conn;
+	int err;
+
+	state = drm_atomic_state_alloc(dev);
+	if (!state)
+		return -ENOMEM;
+
+	state->acquire_ctx = ctx;
+
+	drm_for_each_connector(conn, dev) {
+		struct drm_crtc *crtc = conn->state->crtc;
+		struct drm_crtc_state *crtc_state;
+
+		if (!crtc || conn->dpms != DRM_MODE_DPMS_ON)
+			continue;
+
+		crtc_state = drm_atomic_get_crtc_state(state, crtc);
+		if (IS_ERR(crtc_state)) {
+			err = PTR_ERR(crtc_state);
+			goto free;
+		}
+
+		crtc_state->active = false;
+	}
+
+	err = drm_atomic_commit(state);
+
+free:
+	if (err < 0)
+		drm_atomic_state_free(state);
+
+	return err;
+}
+EXPORT_SYMBOL(drm_atomic_helper_disable_all);
+
+/**
+ * drm_atomic_helper_suspend - subsystem-level suspend helper
+ * @dev: DRM device
+ *
+ * Duplicates the current atomic state, disables all active outputs and then
+ * returns a pointer to the original atomic state to the caller. Drivers can
+ * pass this pointer to the drm_atomic_helper_resume() helper upon resume to
+ * restore the output configuration that was active at the time the system
+ * entered suspend.
+ *
+ * Note that it is potentially unsafe to use this. The atomic state object
+ * returned by this function is assumed to be persistent. Drivers must ensure
+ * that this holds true. Before calling this function, drivers must make sure
+ * to suspend fbdev emulation so that nothing can be using the device.
+ *
+ * Returns:
+ * A pointer to a copy of the state before suspend on success or an ERR_PTR()-
+ * encoded error code on failure. Drivers should store the returned atomic
+ * state object and pass it to the drm_atomic_helper_resume() helper upon
+ * resume.
+ *
+ * See also:
+ * drm_atomic_helper_duplicate_state(), drm_atomic_helper_disable_all(),
+ * drm_atomic_helper_resume()
+ */
+struct drm_atomic_state *drm_atomic_helper_suspend(struct drm_device *dev)
+{
+	struct drm_modeset_acquire_ctx ctx;
+	struct drm_atomic_state *state;
+	int err;
+
+	drm_modeset_acquire_init(&ctx, 0);
+
+retry:
+	err = drm_modeset_lock_all_ctx(dev, &ctx);
+	if (err < 0) {
+		state = ERR_PTR(err);
+		goto unlock;
+	}
+
+	state = drm_atomic_helper_duplicate_state(dev, &ctx);
+	if (IS_ERR(state))
+		goto unlock;
+
+	err = drm_atomic_helper_disable_all(dev, &ctx);
+	if (err < 0) {
+		drm_atomic_state_free(state);
+		state = ERR_PTR(err);
+		goto unlock;
+	}
+
+unlock:
+	if (PTR_ERR(state) == -EDEADLK) {
+		drm_modeset_backoff(&ctx);
+		goto retry;
+	}
+
+	drm_modeset_drop_locks(&ctx);
+	drm_modeset_acquire_fini(&ctx);
+	return state;
+}
+EXPORT_SYMBOL(drm_atomic_helper_suspend);
+
+/**
+ * drm_atomic_helper_resume - subsystem-level resume helper
+ * @dev: DRM device
+ * @state: atomic state to resume to
+ *
+ * Calls drm_mode_config_reset() to synchronize hardware and software states,
+ * grabs all modeset locks and commits the atomic state object. This can be
+ * used in conjunction with the drm_atomic_helper_suspend() helper to
+ * implement suspend/resume for drivers that support atomic mode-setting.
+ *
+ * Returns:
+ * 0 on success or a negative error code on failure.
+ *
+ * See also:
+ * drm_atomic_helper_suspend()
+ */
+int drm_atomic_helper_resume(struct drm_device *dev,
+			     struct drm_atomic_state *state)
+{
+	struct drm_mode_config *config = &dev->mode_config;
+	int err;
+
+	drm_mode_config_reset(dev);
+	drm_modeset_lock_all(dev);
+	state->acquire_ctx = config->acquire_ctx;
+	err = drm_atomic_commit(state);
+	drm_modeset_unlock_all(dev);
+
+	return err;
+}
+EXPORT_SYMBOL(drm_atomic_helper_resume);
+
+/**
+ * drm_atomic_helper_crtc_set_property - helper for crtc properties
+ * @crtc: DRM crtc
+ * @property: DRM property
+ * @val: value of property
+ *
+ * Provides a default crtc set_property handler using the atomic driver
+ * interface.
+ *
+ * RETURNS:
+ * Zero on success, error code on failure
+ */
+int
+drm_atomic_helper_crtc_set_property(struct drm_crtc *crtc,
+				    struct drm_property *property,
+				    uint64_t val)
+{
+	struct drm_atomic_state *state;
+	struct drm_crtc_state *crtc_state;
+	int ret = 0;
+
+	state = drm_atomic_state_alloc(crtc->dev);
+	if (!state)
+		return -ENOMEM;
+
+	/* ->set_property is always called with all locks held. */
+	state->acquire_ctx = crtc->dev->mode_config.acquire_ctx;
+retry:
+	crtc_state = drm_atomic_get_crtc_state(state, crtc);
+	if (IS_ERR(crtc_state)) {
+		ret = PTR_ERR(crtc_state);
+		goto fail;
+	}
+
+	ret = drm_atomic_crtc_set_property(crtc, crtc_state,
+			property, val);
+	if (ret)
+		goto fail;
+
+	ret = drm_atomic_commit(state);
+	if (ret != 0)
+		goto fail;
+
+	/* Driver takes ownership of state on successful commit. */
+	return 0;
+fail:
+	if (ret == -EDEADLK)
+		goto backoff;
+
+	drm_atomic_state_free(state);
+
+	return ret;
+backoff:
+	drm_atomic_state_clear(state);
+	drm_atomic_legacy_backoff(state);
+
+	goto retry;
+}
+EXPORT_SYMBOL(drm_atomic_helper_crtc_set_property);
+
+/**
+ * drm_atomic_helper_plane_set_property - helper for plane properties
+ * @plane: DRM plane
+ * @property: DRM property
+ * @val: value of property
+ *
+ * Provides a default plane set_property handler using the atomic driver
+ * interface.
+ *
+ * RETURNS:
+ * Zero on success, error code on failure
+ */
+int
+drm_atomic_helper_plane_set_property(struct drm_plane *plane,
+				    struct drm_property *property,
+				    uint64_t val)
+{
+	struct drm_atomic_state *state;
+	struct drm_plane_state *plane_state;
+	int ret = 0;
+
+	state = drm_atomic_state_alloc(plane->dev);
+	if (!state)
+		return -ENOMEM;
+
+	/* ->set_property is always called with all locks held. */
+	state->acquire_ctx = plane->dev->mode_config.acquire_ctx;
+retry:
+	plane_state = drm_atomic_get_plane_state(state, plane);
+	if (IS_ERR(plane_state)) {
+		ret = PTR_ERR(plane_state);
+		goto fail;
+	}
+
+	ret = drm_atomic_plane_set_property(plane, plane_state,
+			property, val);
+	if (ret)
+		goto fail;
+
+	ret = drm_atomic_commit(state);
+	if (ret != 0)
+		goto fail;
+
+	/* Driver takes ownership of state on successful commit. */
+	return 0;
+fail:
+	if (ret == -EDEADLK)
+		goto backoff;
+
+	drm_atomic_state_free(state);
+
+	return ret;
+backoff:
+	drm_atomic_state_clear(state);
+	drm_atomic_legacy_backoff(state);
+
+	goto retry;
+}
+EXPORT_SYMBOL(drm_atomic_helper_plane_set_property);
+
+/**
+ * drm_atomic_helper_connector_set_property - helper for connector properties
+ * @connector: DRM connector
+ * @property: DRM property
+ * @val: value of property
+ *
+ * Provides a default connector set_property handler using the atomic driver
+ * interface.
+ *
+ * RETURNS:
+ * Zero on success, error code on failure
+ */
+int
+drm_atomic_helper_connector_set_property(struct drm_connector *connector,
+				    struct drm_property *property,
+				    uint64_t val)
+{
+	struct drm_atomic_state *state;
+	struct drm_connector_state *connector_state;
+	int ret = 0;
+
+	state = drm_atomic_state_alloc(connector->dev);
+	if (!state)
+		return -ENOMEM;
+
+	/* ->set_property is always called with all locks held. */
+	state->acquire_ctx = connector->dev->mode_config.acquire_ctx;
+retry:
+	connector_state = drm_atomic_get_connector_state(state, connector);
+	if (IS_ERR(connector_state)) {
+		ret = PTR_ERR(connector_state);
+		goto fail;
+	}
+
+	ret = drm_atomic_connector_set_property(connector, connector_state,
+			property, val);
+	if (ret)
+		goto fail;
+
+	ret = drm_atomic_commit(state);
+	if (ret != 0)
+		goto fail;
+
+	/* Driver takes ownership of state on successful commit. */
+	return 0;
+fail:
+	if (ret == -EDEADLK)
+		goto backoff;
+
+	drm_atomic_state_free(state);
+
+	return ret;
+backoff:
+	drm_atomic_state_clear(state);
+	drm_atomic_legacy_backoff(state);
+
+	goto retry;
+}
+EXPORT_SYMBOL(drm_atomic_helper_connector_set_property);
+
+/**
+ * drm_atomic_helper_page_flip - execute a legacy page flip
+ * @crtc: DRM crtc
+ * @fb: DRM framebuffer
+ * @event: optional DRM event to signal upon completion
+ * @flags: flip flags for non-vblank sync'ed updates
+ *
+ * Provides a default page flip implementation using the atomic driver interface.
+ *
+ * Note that for now so called async page flips (i.e. updates which are not
+ * synchronized to vblank) are not supported, since the atomic interfaces have
+ * no provisions for this yet.
+ *
+ * Returns:
+ * Returns 0 on success, negative errno numbers on failure.
+ */
+int drm_atomic_helper_page_flip(struct drm_crtc *crtc,
+				struct drm_framebuffer *fb,
+				struct drm_pending_vblank_event *event,
+				uint32_t flags)
+{
+	struct drm_plane *plane = crtc->primary;
+	struct drm_atomic_state *state;
+	struct drm_plane_state *plane_state;
+	struct drm_crtc_state *crtc_state;
+	int ret = 0;
+
+	if (flags & DRM_MODE_PAGE_FLIP_ASYNC)
+		return -EINVAL;
+
+	state = drm_atomic_state_alloc(plane->dev);
+	if (!state)
+		return -ENOMEM;
+
+	state->acquire_ctx = drm_modeset_legacy_acquire_ctx(crtc);
+retry:
+	crtc_state = drm_atomic_get_crtc_state(state, crtc);
+	if (IS_ERR(crtc_state)) {
+		ret = PTR_ERR(crtc_state);
+		goto fail;
+	}
+	crtc_state->event = event;
+
+	plane_state = drm_atomic_get_plane_state(state, plane);
+	if (IS_ERR(plane_state)) {
+		ret = PTR_ERR(plane_state);
+		goto fail;
+	}
+
+	ret = drm_atomic_set_crtc_for_plane(plane_state, crtc);
+	if (ret != 0)
+		goto fail;
+	drm_atomic_set_fb_for_plane(plane_state, fb);
+
+	/* Make sure we don't accidentally do a full modeset. */
+	state->allow_modeset = false;
+	if (!crtc_state->active) {
+		DRM_DEBUG_ATOMIC("[CRTC:%d] disabled, rejecting legacy flip\n",
+				 crtc->base.id);
+		ret = -EINVAL;
+		goto fail;
+	}
+
+	ret = drm_atomic_nonblocking_commit(state);
+	if (ret != 0)
+		goto fail;
+
+	/* Driver takes ownership of state on successful commit. */
+	return 0;
+fail:
+	if (ret == -EDEADLK)
+		goto backoff;
+
+	drm_atomic_state_free(state);
+
+	return ret;
+backoff:
+	drm_atomic_state_clear(state);
+	drm_atomic_legacy_backoff(state);
+
+	/*
+	 * Someone might have exchanged the framebuffer while we dropped locks
+	 * in the backoff code. We need to fix up the fb refcount tracking the
+	 * core does for us.
+	 */
+	plane->old_fb = plane->fb;
+
+	goto retry;
+}
+EXPORT_SYMBOL(drm_atomic_helper_page_flip);
+
+/**
+ * drm_atomic_helper_connector_dpms() - connector dpms helper implementation
+ * @connector: affected connector
+ * @mode: DPMS mode
+ *
+ * This is the main helper function provided by the atomic helper framework for
+ * implementing the legacy DPMS connector interface. It computes the new desired
+ * ->active state for the corresponding CRTC (if the connector is enabled) and
+ *  updates it.
+ *
+ * Returns:
+ * Returns 0 on success, negative errno numbers on failure.
+ */
+int drm_atomic_helper_connector_dpms(struct drm_connector *connector,
+				     int mode)
+{
+	struct drm_mode_config *config = &connector->dev->mode_config;
+	struct drm_atomic_state *state;
+	struct drm_crtc_state *crtc_state;
+	struct drm_crtc *crtc;
+	struct drm_connector *tmp_connector;
+	int ret;
+	bool active = false;
+	int old_mode = connector->dpms;
+
+	if (mode != DRM_MODE_DPMS_ON)
+		mode = DRM_MODE_DPMS_OFF;
+
+	connector->dpms = mode;
+	crtc = connector->state->crtc;
+
+	if (!crtc)
+		return 0;
+
+	state = drm_atomic_state_alloc(connector->dev);
+	if (!state)
+		return -ENOMEM;
+
+	state->acquire_ctx = drm_modeset_legacy_acquire_ctx(crtc);
+retry:
+	crtc_state = drm_atomic_get_crtc_state(state, crtc);
+	if (IS_ERR(crtc_state)) {
+		ret = PTR_ERR(crtc_state);
+		goto fail;
+	}
+
+	WARN_ON(!drm_modeset_is_locked(&config->connection_mutex));
+
+	drm_for_each_connector(tmp_connector, connector->dev) {
+		if (tmp_connector->state->crtc != crtc)
+			continue;
+
+		if (tmp_connector->dpms == DRM_MODE_DPMS_ON) {
+			active = true;
+			break;
+		}
+	}
+	crtc_state->active = active;
+
+	ret = drm_atomic_commit(state);
+	if (ret != 0)
+		goto fail;
+
+	/* Driver takes ownership of state on successful commit. */
+	return 0;
+fail:
+	if (ret == -EDEADLK)
+		goto backoff;
+
+	connector->dpms = old_mode;
+	drm_atomic_state_free(state);
+
+	return ret;
+backoff:
+	drm_atomic_state_clear(state);
+	drm_atomic_legacy_backoff(state);
+
+	goto retry;
+}
+EXPORT_SYMBOL(drm_atomic_helper_connector_dpms);
+
+/**
+ * drm_atomic_helper_best_encoder - Helper for &drm_connector_helper_funcs
+ *                                  ->best_encoder callback
+ * @connector: Connector control structure
+ *
+ * This is a &drm_connector_helper_funcs ->best_encoder callback helper for
+ * connectors that support exactly 1 encoder, statically determined at driver
+ * init time.
+ */
+struct drm_encoder *
+drm_atomic_helper_best_encoder(struct drm_connector *connector)
+{
+	WARN_ON(connector->encoder_ids[1]);
+	return drm_encoder_find(connector->dev, connector->encoder_ids[0]);
+}
+EXPORT_SYMBOL(drm_atomic_helper_best_encoder);
+
+/**
+ * DOC: atomic state reset and initialization
+ *
+ * Both the drm core and the atomic helpers assume that there is always the full
+ * and correct atomic software state for all connectors, CRTCs and planes
+ * available. Which is a bit a problem on driver load and also after system
+ * suspend. One way to solve this is to have a hardware state read-out
+ * infrastructure which reconstructs the full software state (e.g. the i915
+ * driver).
+ *
+ * The simpler solution is to just reset the software state to everything off,
+ * which is easiest to do by calling drm_mode_config_reset(). To facilitate this
+ * the atomic helpers provide default reset implementations for all hooks.
+ *
+ * On the upside the precise state tracking of atomic simplifies system suspend
+ * and resume a lot. For drivers using drm_mode_config_reset() a complete recipe
+ * is implemented in drm_atomic_helper_suspend() and drm_atomic_helper_resume().
+ * For other drivers the building blocks are split out, see the documentation
+ * for these functions.
+ */
+
+/**
+ * drm_atomic_helper_crtc_reset - default ->reset hook for CRTCs
+ * @crtc: drm CRTC
+ *
+ * Resets the atomic state for @crtc by freeing the state pointer (which might
+ * be NULL, e.g. at driver load time) and allocating a new empty state object.
+ */
+void drm_atomic_helper_crtc_reset(struct drm_crtc *crtc)
+{
+	if (crtc->state)
+		__drm_atomic_helper_crtc_destroy_state(crtc->state);
+
+	kfree(crtc->state);
+	crtc->state = kzalloc(sizeof(*crtc->state), GFP_KERNEL);
+
+	if (crtc->state)
+		crtc->state->crtc = crtc;
+}
+EXPORT_SYMBOL(drm_atomic_helper_crtc_reset);
+
+/**
+ * __drm_atomic_helper_crtc_duplicate_state - copy atomic CRTC state
+ * @crtc: CRTC object
+ * @state: atomic CRTC state
+ *
+ * Copies atomic state from a CRTC's current state and resets inferred values.
+ * This is useful for drivers that subclass the CRTC state.
+ */
+void __drm_atomic_helper_crtc_duplicate_state(struct drm_crtc *crtc,
+					      struct drm_crtc_state *state)
+{
+	memcpy(state, crtc->state, sizeof(*state));
+
+	if (state->mode_blob)
+		drm_property_reference_blob(state->mode_blob);
+	if (state->degamma_lut)
+		drm_property_reference_blob(state->degamma_lut);
+	if (state->ctm)
+		drm_property_reference_blob(state->ctm);
+	if (state->gamma_lut)
+		drm_property_reference_blob(state->gamma_lut);
+	state->mode_changed = false;
+	state->active_changed = false;
+	state->planes_changed = false;
+	state->connectors_changed = false;
+	state->color_mgmt_changed = false;
+	state->event = NULL;
+}
+EXPORT_SYMBOL(__drm_atomic_helper_crtc_duplicate_state);
+
+/**
+ * drm_atomic_helper_crtc_duplicate_state - default state duplicate hook
+ * @crtc: drm CRTC
+ *
+ * Default CRTC state duplicate hook for drivers which don't have their own
+ * subclassed CRTC state structure.
+ */
+struct drm_crtc_state *
+drm_atomic_helper_crtc_duplicate_state(struct drm_crtc *crtc)
+{
+	struct drm_crtc_state *state;
+
+	if (WARN_ON(!crtc->state))
+		return NULL;
+
+	state = kmalloc(sizeof(*state), GFP_KERNEL);
+	if (state)
+		__drm_atomic_helper_crtc_duplicate_state(crtc, state);
+
+	return state;
+}
+EXPORT_SYMBOL(drm_atomic_helper_crtc_duplicate_state);
+
+/**
+ * __drm_atomic_helper_crtc_destroy_state - release CRTC state
+ * @state: CRTC state object to release
+ *
+ * Releases all resources stored in the CRTC state without actually freeing
+ * the memory of the CRTC state. This is useful for drivers that subclass the
+ * CRTC state.
+ */
+void __drm_atomic_helper_crtc_destroy_state(struct drm_crtc_state *state)
+{
+	drm_property_unreference_blob(state->mode_blob);
+	drm_property_unreference_blob(state->degamma_lut);
+	drm_property_unreference_blob(state->ctm);
+	drm_property_unreference_blob(state->gamma_lut);
+}
+EXPORT_SYMBOL(__drm_atomic_helper_crtc_destroy_state);
+
+/**
+ * drm_atomic_helper_crtc_destroy_state - default state destroy hook
+ * @crtc: drm CRTC
+ * @state: CRTC state object to release
+ *
+ * Default CRTC state destroy hook for drivers which don't have their own
+ * subclassed CRTC state structure.
+ */
+void drm_atomic_helper_crtc_destroy_state(struct drm_crtc *crtc,
+					  struct drm_crtc_state *state)
+{
+	__drm_atomic_helper_crtc_destroy_state(state);
+	kfree(state);
+}
+EXPORT_SYMBOL(drm_atomic_helper_crtc_destroy_state);
+
+/**
+ * drm_atomic_helper_plane_reset - default ->reset hook for planes
+ * @plane: drm plane
+ *
+ * Resets the atomic state for @plane by freeing the state pointer (which might
+ * be NULL, e.g. at driver load time) and allocating a new empty state object.
+ */
+void drm_atomic_helper_plane_reset(struct drm_plane *plane)
+{
+	if (plane->state)
+		__drm_atomic_helper_plane_destroy_state(plane->state);
+
+	kfree(plane->state);
+	plane->state = kzalloc(sizeof(*plane->state), GFP_KERNEL);
+
+	if (plane->state) {
+		plane->state->plane = plane;
+		plane->state->rotation = BIT(DRM_ROTATE_0);
+	}
+}
+EXPORT_SYMBOL(drm_atomic_helper_plane_reset);
+
+/**
+ * __drm_atomic_helper_plane_duplicate_state - copy atomic plane state
+ * @plane: plane object
+ * @state: atomic plane state
+ *
+ * Copies atomic state from a plane's current state. This is useful for
+ * drivers that subclass the plane state.
+ */
+void __drm_atomic_helper_plane_duplicate_state(struct drm_plane *plane,
+					       struct drm_plane_state *state)
+{
+	memcpy(state, plane->state, sizeof(*state));
+
+	if (state->fb)
+		drm_framebuffer_reference(state->fb);
+}
+EXPORT_SYMBOL(__drm_atomic_helper_plane_duplicate_state);
+
+/**
+ * drm_atomic_helper_plane_duplicate_state - default state duplicate hook
+ * @plane: drm plane
+ *
+ * Default plane state duplicate hook for drivers which don't have their own
+ * subclassed plane state structure.
+ */
+struct drm_plane_state *
+drm_atomic_helper_plane_duplicate_state(struct drm_plane *plane)
+{
+	struct drm_plane_state *state;
+
+	if (WARN_ON(!plane->state))
+		return NULL;
+
+	state = kmalloc(sizeof(*state), GFP_KERNEL);
+	if (state)
+		__drm_atomic_helper_plane_duplicate_state(plane, state);
+
+	return state;
+}
+EXPORT_SYMBOL(drm_atomic_helper_plane_duplicate_state);
+
+/**
+ * __drm_atomic_helper_plane_destroy_state - release plane state
+ * @state: plane state object to release
+ *
+ * Releases all resources stored in the plane state without actually freeing
+ * the memory of the plane state. This is useful for drivers that subclass the
+ * plane state.
+ */
+void __drm_atomic_helper_plane_destroy_state(struct drm_plane_state *state)
+{
+	if (state->fb)
+		drm_framebuffer_unreference(state->fb);
+}
+EXPORT_SYMBOL(__drm_atomic_helper_plane_destroy_state);
+
+/**
+ * drm_atomic_helper_plane_destroy_state - default state destroy hook
+ * @plane: drm plane
+ * @state: plane state object to release
+ *
+ * Default plane state destroy hook for drivers which don't have their own
+ * subclassed plane state structure.
+ */
+void drm_atomic_helper_plane_destroy_state(struct drm_plane *plane,
+					   struct drm_plane_state *state)
+{
+	__drm_atomic_helper_plane_destroy_state(state);
+	kfree(state);
+}
+EXPORT_SYMBOL(drm_atomic_helper_plane_destroy_state);
+
+/**
+ * __drm_atomic_helper_connector_reset - reset state on connector
+ * @connector: drm connector
+ * @conn_state: connector state to assign
+ *
+ * Initializes the newly allocated @conn_state and assigns it to
+ * #connector ->state, usually required when initializing the drivers
+ * or when called from the ->reset hook.
+ *
+ * This is useful for drivers that subclass the connector state.
+ */
+void
+__drm_atomic_helper_connector_reset(struct drm_connector *connector,
+				    struct drm_connector_state *conn_state)
+{
+	if (conn_state)
+		conn_state->connector = connector;
+
+	connector->state = conn_state;
+}
+EXPORT_SYMBOL(__drm_atomic_helper_connector_reset);
+
+/**
+ * drm_atomic_helper_connector_reset - default ->reset hook for connectors
+ * @connector: drm connector
+ *
+ * Resets the atomic state for @connector by freeing the state pointer (which
+ * might be NULL, e.g. at driver load time) and allocating a new empty state
+ * object.
+ */
+void drm_atomic_helper_connector_reset(struct drm_connector *connector)
+{
+	struct drm_connector_state *conn_state =
+		kzalloc(sizeof(*conn_state), GFP_KERNEL);
+
+	if (connector->state)
+		__drm_atomic_helper_connector_destroy_state(connector->state);
+
+	kfree(connector->state);
+	__drm_atomic_helper_connector_reset(connector, conn_state);
+}
+EXPORT_SYMBOL(drm_atomic_helper_connector_reset);
+
+/**
+ * __drm_atomic_helper_connector_duplicate_state - copy atomic connector state
+ * @connector: connector object
+ * @state: atomic connector state
+ *
+ * Copies atomic state from a connector's current state. This is useful for
+ * drivers that subclass the connector state.
+ */
+void
+__drm_atomic_helper_connector_duplicate_state(struct drm_connector *connector,
+					    struct drm_connector_state *state)
+{
+	memcpy(state, connector->state, sizeof(*state));
+	if (state->crtc)
+		drm_connector_reference(connector);
+}
+EXPORT_SYMBOL(__drm_atomic_helper_connector_duplicate_state);
+
+/**
+ * drm_atomic_helper_connector_duplicate_state - default state duplicate hook
+ * @connector: drm connector
+ *
+ * Default connector state duplicate hook for drivers which don't have their own
+ * subclassed connector state structure.
+ */
+struct drm_connector_state *
+drm_atomic_helper_connector_duplicate_state(struct drm_connector *connector)
+{
+	struct drm_connector_state *state;
+
+	if (WARN_ON(!connector->state))
+		return NULL;
+
+	state = kmalloc(sizeof(*state), GFP_KERNEL);
+	if (state)
+		__drm_atomic_helper_connector_duplicate_state(connector, state);
+
+	return state;
+}
+EXPORT_SYMBOL(drm_atomic_helper_connector_duplicate_state);
+
+/**
+ * drm_atomic_helper_duplicate_state - duplicate an atomic state object
+ * @dev: DRM device
+ * @ctx: lock acquisition context
+ *
+ * Makes a copy of the current atomic state by looping over all objects and
+ * duplicating their respective states. This is used for example by suspend/
+ * resume support code to save the state prior to suspend such that it can
+ * be restored upon resume.
+ *
+ * Note that this treats atomic state as persistent between save and restore.
+ * Drivers must make sure that this is possible and won't result in confusion
+ * or erroneous behaviour.
+ *
+ * Note that if callers haven't already acquired all modeset locks this might
+ * return -EDEADLK, which must be handled by calling drm_modeset_backoff().
+ *
+ * Returns:
+ * A pointer to the copy of the atomic state object on success or an
+ * ERR_PTR()-encoded error code on failure.
+ *
+ * See also:
+ * drm_atomic_helper_suspend(), drm_atomic_helper_resume()
+ */
+struct drm_atomic_state *
+drm_atomic_helper_duplicate_state(struct drm_device *dev,
+				  struct drm_modeset_acquire_ctx *ctx)
+{
+	struct drm_atomic_state *state;
+	struct drm_connector *conn;
+	struct drm_plane *plane;
+	struct drm_crtc *crtc;
+	int err = 0;
+
+	state = drm_atomic_state_alloc(dev);
+	if (!state)
+		return ERR_PTR(-ENOMEM);
+
+	state->acquire_ctx = ctx;
+
+	drm_for_each_crtc(crtc, dev) {
+		struct drm_crtc_state *crtc_state;
+
+		crtc_state = drm_atomic_get_crtc_state(state, crtc);
+		if (IS_ERR(crtc_state)) {
+			err = PTR_ERR(crtc_state);
+			goto free;
+		}
+	}
+
+	drm_for_each_plane(plane, dev) {
+		struct drm_plane_state *plane_state;
+
+		plane_state = drm_atomic_get_plane_state(state, plane);
+		if (IS_ERR(plane_state)) {
+			err = PTR_ERR(plane_state);
+			goto free;
+		}
+	}
+
+	drm_for_each_connector(conn, dev) {
+		struct drm_connector_state *conn_state;
+
+		conn_state = drm_atomic_get_connector_state(state, conn);
+		if (IS_ERR(conn_state)) {
+			err = PTR_ERR(conn_state);
+			goto free;
+		}
+	}
+
+	/* clear the acquire context so that it isn't accidentally reused */
+	state->acquire_ctx = NULL;
+
+free:
+	if (err < 0) {
+		drm_atomic_state_free(state);
+		state = ERR_PTR(err);
+	}
+
+	return state;
+}
+EXPORT_SYMBOL(drm_atomic_helper_duplicate_state);
+
+/**
+ * __drm_atomic_helper_connector_destroy_state - release connector state
+ * @state: connector state object to release
+ *
+ * Releases all resources stored in the connector state without actually
+ * freeing the memory of the connector state. This is useful for drivers that
+ * subclass the connector state.
+ */
+void
+__drm_atomic_helper_connector_destroy_state(struct drm_connector_state *state)
+{
+	/*
+	 * This is currently a placeholder so that drivers that subclass the
+	 * state will automatically do the right thing if code is ever added
+	 * to this function.
+	 */
+	if (state->crtc)
+		drm_connector_unreference(state->connector);
+}
+EXPORT_SYMBOL(__drm_atomic_helper_connector_destroy_state);
+
+/**
+ * drm_atomic_helper_connector_destroy_state - default state destroy hook
+ * @connector: drm connector
+ * @state: connector state object to release
+ *
+ * Default connector state destroy hook for drivers which don't have their own
+ * subclassed connector state structure.
+ */
+void drm_atomic_helper_connector_destroy_state(struct drm_connector *connector,
+					  struct drm_connector_state *state)
+{
+	__drm_atomic_helper_connector_destroy_state(state);
+	kfree(state);
+}
+EXPORT_SYMBOL(drm_atomic_helper_connector_destroy_state);
+
+/**
+ * drm_atomic_helper_legacy_gamma_set - set the legacy gamma correction table
+ * @crtc: CRTC object
+ * @red: red correction table
+ * @green: green correction table
+ * @blue: green correction table
+ * @start:
+ * @size: size of the tables
+ *
+ * Implements support for legacy gamma correction table for drivers
+ * that support color management through the DEGAMMA_LUT/GAMMA_LUT
+ * properties.
+ */
+void drm_atomic_helper_legacy_gamma_set(struct drm_crtc *crtc,
+					u16 *red, u16 *green, u16 *blue,
+					uint32_t start, uint32_t size)
+{
+	struct drm_device *dev = crtc->dev;
+	struct drm_mode_config *config = &dev->mode_config;
+	struct drm_atomic_state *state;
+	struct drm_crtc_state *crtc_state;
+	struct drm_property_blob *blob = NULL;
+	struct drm_color_lut *blob_data;
+	int i, ret = 0;
+
+	state = drm_atomic_state_alloc(crtc->dev);
+	if (!state)
+		return;
+
+	blob = drm_property_create_blob(dev,
+					sizeof(struct drm_color_lut) * size,
+					NULL);
+	if (IS_ERR(blob)) {
+		ret = PTR_ERR(blob);
+		blob = NULL;
+		goto fail;
+	}
+
+	/* Prepare GAMMA_LUT with the legacy values. */
+	blob_data = (struct drm_color_lut *) blob->data;
+	for (i = 0; i < size; i++) {
+		blob_data[i].red = red[i];
+		blob_data[i].green = green[i];
+		blob_data[i].blue = blue[i];
+	}
+
+	state->acquire_ctx = crtc->dev->mode_config.acquire_ctx;
+retry:
+	crtc_state = drm_atomic_get_crtc_state(state, crtc);
+	if (IS_ERR(crtc_state)) {
+		ret = PTR_ERR(crtc_state);
+		goto fail;
+	}
+
+	/* Reset DEGAMMA_LUT and CTM properties. */
+	ret = drm_atomic_crtc_set_property(crtc, crtc_state,
+			config->degamma_lut_property, 0);
+	if (ret)
+		goto fail;
+
+	ret = drm_atomic_crtc_set_property(crtc, crtc_state,
+			config->ctm_property, 0);
+	if (ret)
+		goto fail;
+
+	ret = drm_atomic_crtc_set_property(crtc, crtc_state,
+			config->gamma_lut_property, blob->base.id);
+	if (ret)
+		goto fail;
+
+	ret = drm_atomic_commit(state);
+	if (ret)
+		goto fail;
+
+	/* Driver takes ownership of state on successful commit. */
+
+	drm_property_unreference_blob(blob);
+
+	return;
+fail:
+	if (ret == -EDEADLK)
+		goto backoff;
+
+	drm_atomic_state_free(state);
+	drm_property_unreference_blob(blob);
+
+	return;
+backoff:
+	drm_atomic_state_clear(state);
+	drm_atomic_legacy_backoff(state);
+
+	goto retry;
+}
+EXPORT_SYMBOL(drm_atomic_helper_legacy_gamma_set);