drivers/gpu/drm/drm_mode_object.c - third_party/linux - Git at Google

 /*
  * Copyright (c) 2016 Intel Corporation
  *
  * Permission to use, copy, modify, distribute, and sell this software and its
  * documentation for any purpose is hereby granted without fee, provided that
  * the above copyright notice appear in all copies and that both that copyright
  * notice and this permission notice appear in supporting documentation, and
  * that the name of the copyright holders not be used in advertising or
  * publicity pertaining to distribution of the software without specific,
  * written prior permission.  The copyright holders make no representations
  * about the suitability of this software for any purpose.  It is provided "as
  * is" without express or implied warranty.
  *
  * THE COPYRIGHT HOLDERS DISCLAIM ALL WARRANTIES WITH REGARD TO THIS SOFTWARE,
  * INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS, IN NO
  * EVENT SHALL THE COPYRIGHT HOLDERS BE LIABLE FOR ANY SPECIAL, INDIRECT OR
  * CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF USE,
  * DATA OR PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER
  * TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE
  * OF THIS SOFTWARE.
  */

 #include <linux/export.h>
 #include <drm/drmP.h>
 #include <drm/drm_mode_object.h>
 #include <drm/drm_atomic.h>

 #include "drm_crtc_internal.h"

 /*
  * Internal function to assign a slot in the object idr and optionally
  * register the object into the idr.
  */
 int __drm_mode_object_add(struct drm_device *dev, struct drm_mode_object *obj,
 			  uint32_t obj_type, bool register_obj,
 			  void (*obj_free_cb)(struct kref *kref))
 {
 	int ret;

 	mutex_lock(&dev->mode_config.idr_mutex);
 	ret = idr_alloc(&dev->mode_config.crtc_idr, register_obj ? obj : NULL, 1, 0, GFP_KERNEL);
 	if (ret >= 0) {
 		/*
 		 * Set up the object linking under the protection of the idr
 		 * lock so that other users can't see inconsistent state.
 		 */
 		obj->id = ret;
 		obj->type = obj_type;
 		if (obj_free_cb) {
 			obj->free_cb = obj_free_cb;
 			kref_init(&obj->refcount);
 		}
 	}
 	mutex_unlock(&dev->mode_config.idr_mutex);

 	return ret < 0 ? ret : 0;
 }

 /**
  * drm_mode_object_add - allocate a new modeset identifier
  * @dev: DRM device
  * @obj: object pointer, used to generate unique ID
  * @obj_type: object type
  *
  * Create a unique identifier based on @ptr in @dev's identifier space.  Used
  * for tracking modes, CRTCs and connectors.
  *
  * Returns:
  * Zero on success, error code on failure.
  */
 int drm_mode_object_add(struct drm_device *dev,
 			struct drm_mode_object *obj, uint32_t obj_type)
 {
 	return __drm_mode_object_add(dev, obj, obj_type, true, NULL);
 }

 void drm_mode_object_register(struct drm_device *dev,
 			      struct drm_mode_object *obj)
 {
 	mutex_lock(&dev->mode_config.idr_mutex);
 	idr_replace(&dev->mode_config.crtc_idr, obj, obj->id);
 	mutex_unlock(&dev->mode_config.idr_mutex);
 }

 /**
  * drm_mode_object_unregister - free a modeset identifer
  * @dev: DRM device
  * @object: object to free
  *
  * Free @id from @dev's unique identifier pool.
  * This function can be called multiple times, and guards against
  * multiple removals.
  * These modeset identifiers are _not_ reference counted. Hence don't use this
  * for reference counted modeset objects like framebuffers.
  */
 void drm_mode_object_unregister(struct drm_device *dev,
 				struct drm_mode_object *object)
 {
 	mutex_lock(&dev->mode_config.idr_mutex);
 	if (object->id) {
 		idr_remove(&dev->mode_config.crtc_idr, object->id);
 		object->id = 0;
 	}
 	mutex_unlock(&dev->mode_config.idr_mutex);
 }

 /**
  * drm_lease_required - check types which must be leased to be used
  * @type: type of object
  *
  * Returns whether the provided type of drm_mode_object must
  * be owned or leased to be used by a process.
  */
 bool drm_mode_object_lease_required(uint32_t type)
 {
 	switch(type) {
 	case DRM_MODE_OBJECT_CRTC:
 	case DRM_MODE_OBJECT_CONNECTOR:
 	case DRM_MODE_OBJECT_PLANE:
 		return true;
 	default:
 		return false;
 	}
 }

 struct drm_mode_object *__drm_mode_object_find(struct drm_device *dev,
 					       struct drm_file *file_priv,
 					       uint32_t id, uint32_t type)
 {
 	struct drm_mode_object *obj = NULL;

 	mutex_lock(&dev->mode_config.idr_mutex);
 	obj = idr_find(&dev->mode_config.crtc_idr, id);
 	if (obj && type != DRM_MODE_OBJECT_ANY && obj->type != type)
 		obj = NULL;
 	if (obj && obj->id != id)
 		obj = NULL;

 	if (obj && drm_mode_object_lease_required(obj->type) &&
 	    !_drm_lease_held(file_priv, obj->id))
 		obj = NULL;

 	if (obj && obj->free_cb) {
 		if (!kref_get_unless_zero(&obj->refcount))
 			obj = NULL;
 	}
 	mutex_unlock(&dev->mode_config.idr_mutex);

 	return obj;
 }

 /**
  * drm_mode_object_find - look up a drm object with static lifetime
  * @dev: drm device
  * @file_priv: drm file
  * @id: id of the mode object
  * @type: type of the mode object
  *
  * This function is used to look up a modeset object. It will acquire a
  * reference for reference counted objects. This reference must be dropped again
  * by callind drm_mode_object_put().
  */
 struct drm_mode_object *drm_mode_object_find(struct drm_device *dev,
 		struct drm_file *file_priv,
 		uint32_t id, uint32_t type)
 {
 	struct drm_mode_object *obj = NULL;

 	obj = __drm_mode_object_find(dev, file_priv, id, type);
 	return obj;
 }
 EXPORT_SYMBOL(drm_mode_object_find);

 /**
  * drm_mode_object_put - release a mode object reference
  * @obj: DRM mode object
  *
  * This function decrements the object's refcount if it is a refcounted modeset
  * object. It is a no-op on any other object. This is used to drop references
  * acquired with drm_mode_object_get().
  */
 void drm_mode_object_put(struct drm_mode_object *obj)
 {
 	if (obj->free_cb) {
 		DRM_DEBUG("OBJ ID: %d (%d)\n", obj->id, kref_read(&obj->refcount));
 		kref_put(&obj->refcount, obj->free_cb);
 	}
 }
 EXPORT_SYMBOL(drm_mode_object_put);

 /**
  * drm_mode_object_get - acquire a mode object reference
  * @obj: DRM mode object
  *
  * This function increments the object's refcount if it is a refcounted modeset
  * object. It is a no-op on any other object. References should be dropped again
  * by calling drm_mode_object_put().
  */
 void drm_mode_object_get(struct drm_mode_object *obj)
 {
 	if (obj->free_cb) {
 		DRM_DEBUG("OBJ ID: %d (%d)\n", obj->id, kref_read(&obj->refcount));
 		kref_get(&obj->refcount);
 	}
 }
 EXPORT_SYMBOL(drm_mode_object_get);

 /**
  * drm_object_attach_property - attach a property to a modeset object
  * @obj: drm modeset object
  * @property: property to attach
  * @init_val: initial value of the property
  *
  * This attaches the given property to the modeset object with the given initial
  * value. Currently this function cannot fail since the properties are stored in
  * a statically sized array.
  */
 void drm_object_attach_property(struct drm_mode_object *obj,
 				struct drm_property *property,
 				uint64_t init_val)
 {
 	int count = obj->properties->count;

 	if (count == DRM_OBJECT_MAX_PROPERTY) {
 		WARN(1, "Failed to attach object property (type: 0x%x). Please "
 			"increase DRM_OBJECT_MAX_PROPERTY by 1 for each time "
 			"you see this message on the same object type.\n",
 			obj->type);
 		return;
 	}

 	obj->properties->properties[count] = property;
 	obj->properties->values[count] = init_val;
 	obj->properties->count++;
 }
 EXPORT_SYMBOL(drm_object_attach_property);

 /**
  * drm_object_property_set_value - set the value of a property
  * @obj: drm mode object to set property value for
  * @property: property to set
  * @val: value the property should be set to
  *
  * This function sets a given property on a given object. This function only
  * changes the software state of the property, it does not call into the
  * driver's ->set_property callback.
  *
  * Note that atomic drivers should not have any need to call this, the core will
  * ensure consistency of values reported back to userspace through the
  * appropriate ->atomic_get_property callback. Only legacy drivers should call
  * this function to update the tracked value (after clamping and other
  * restrictions have been applied).
  *
  * Returns:
  * Zero on success, error code on failure.
  */
 int drm_object_property_set_value(struct drm_mode_object *obj,
 				  struct drm_property *property, uint64_t val)
 {
 	int i;

 	WARN_ON(drm_drv_uses_atomic_modeset(property->dev) &&
 		!(property->flags & DRM_MODE_PROP_IMMUTABLE));

 	for (i = 0; i < obj->properties->count; i++) {
 		if (obj->properties->properties[i] == property) {
 			obj->properties->values[i] = val;
 			return 0;
 		}
 	}

 	return -EINVAL;
 }
 EXPORT_SYMBOL(drm_object_property_set_value);

 static int __drm_object_property_get_value(struct drm_mode_object *obj,
 					   struct drm_property *property,
 					   uint64_t *val)
 {
 	int i;

 	/* read-only properties bypass atomic mechanism and still store
 	 * their value in obj->properties->values[].. mostly to avoid
 	 * having to deal w/ EDID and similar props in atomic paths:
 	 */
 	if (drm_drv_uses_atomic_modeset(property->dev) &&
 			!(property->flags & DRM_MODE_PROP_IMMUTABLE))
 		return drm_atomic_get_property(obj, property, val);

 	for (i = 0; i < obj->properties->count; i++) {
 		if (obj->properties->properties[i] == property) {
 			*val = obj->properties->values[i];
 			return 0;
 		}

 	}

 	return -EINVAL;
 }

 /**
  * drm_object_property_get_value - retrieve the value of a property
  * @obj: drm mode object to get property value from
  * @property: property to retrieve
  * @val: storage for the property value
  *
  * This function retrieves the softare state of the given property for the given
  * property. Since there is no driver callback to retrieve the current property
  * value this might be out of sync with the hardware, depending upon the driver
  * and property.
  *
  * Atomic drivers should never call this function directly, the core will read
  * out property values through the various ->atomic_get_property callbacks.
  *
  * Returns:
  * Zero on success, error code on failure.
  */
 int drm_object_property_get_value(struct drm_mode_object *obj,
 				  struct drm_property *property, uint64_t *val)
 {
 	WARN_ON(drm_drv_uses_atomic_modeset(property->dev));

 	return __drm_object_property_get_value(obj, property, val);
 }
 EXPORT_SYMBOL(drm_object_property_get_value);

 /* helper for getconnector and getproperties ioctls */
 int drm_mode_object_get_properties(struct drm_mode_object *obj, bool atomic,
 				   uint32_t __user *prop_ptr,
 				   uint64_t __user *prop_values,
 				   uint32_t *arg_count_props)
 {
 	int i, ret, count;

 	for (i = 0, count = 0; i < obj->properties->count; i++) {
 		struct drm_property *prop = obj->properties->properties[i];
 		uint64_t val;

 		if ((prop->flags & DRM_MODE_PROP_ATOMIC) && !atomic)
 			continue;

 		if (*arg_count_props > count) {
 			ret = __drm_object_property_get_value(obj, prop, &val);
 			if (ret)
 				return ret;

 			if (put_user(prop->base.id, prop_ptr + count))
 				return -EFAULT;

 			if (put_user(val, prop_values + count))
 				return -EFAULT;
 		}

 		count++;
 	}
 	*arg_count_props = count;

 	return 0;
 }

 /**
  * drm_mode_obj_get_properties_ioctl - get the current value of a object's property
  * @dev: DRM device
  * @data: ioctl data
  * @file_priv: DRM file info
  *
  * This function retrieves the current value for an object's property. Compared
  * to the connector specific ioctl this one is extended to also work on crtc and
  * plane objects.
  *
  * Called by the user via ioctl.
  *
  * Returns:
  * Zero on success, negative errno on failure.
  */
 int drm_mode_obj_get_properties_ioctl(struct drm_device *dev, void *data,
 				      struct drm_file *file_priv)
 {
 	struct drm_mode_obj_get_properties *arg = data;
 	struct drm_mode_object *obj;
 	int ret = 0;

 	if (!drm_core_check_feature(dev, DRIVER_MODESET))
 		return -EINVAL;

 	drm_modeset_lock_all(dev);

 	obj = drm_mode_object_find(dev, file_priv, arg->obj_id, arg->obj_type);
 	if (!obj) {
 		ret = -ENOENT;
 		goto out;
 	}
 	if (!obj->properties) {
 		ret = -EINVAL;
 		goto out_unref;
 	}

 	ret = drm_mode_object_get_properties(obj, file_priv->atomic,
 			(uint32_t __user *)(unsigned long)(arg->props_ptr),
 			(uint64_t __user *)(unsigned long)(arg->prop_values_ptr),
 			&arg->count_props);

 out_unref:
 	drm_mode_object_put(obj);
 out:
 	drm_modeset_unlock_all(dev);
 	return ret;
 }

 struct drm_property *drm_mode_obj_find_prop_id(struct drm_mode_object *obj,
 					       uint32_t prop_id)
 {
 	int i;

 	for (i = 0; i < obj->properties->count; i++)
 		if (obj->properties->properties[i]->base.id == prop_id)
 			return obj->properties->properties[i];

 	return NULL;
 }

 static int set_property_legacy(struct drm_mode_object *obj,
 			       struct drm_property *prop,
 			       uint64_t prop_value)
 {
 	struct drm_device *dev = prop->dev;
 	struct drm_mode_object *ref;
 	int ret = -EINVAL;

 	if (!drm_property_change_valid_get(prop, prop_value, &ref))
 		return -EINVAL;

 	drm_modeset_lock_all(dev);
 	switch (obj->type) {
 	case DRM_MODE_OBJECT_CONNECTOR:
 		ret = drm_mode_connector_set_obj_prop(obj, prop,
 						      prop_value);
 		break;
 	case DRM_MODE_OBJECT_CRTC:
 		ret = drm_mode_crtc_set_obj_prop(obj, prop, prop_value);
 		break;
 	case DRM_MODE_OBJECT_PLANE:
 		ret = drm_mode_plane_set_obj_prop(obj_to_plane(obj),
 						  prop, prop_value);
 		break;
 	}
 	drm_property_change_valid_put(prop, ref);
 	drm_modeset_unlock_all(dev);

 	return ret;
 }

 static int set_property_atomic(struct drm_mode_object *obj,
 			       struct drm_property *prop,
 			       uint64_t prop_value)
 {
 	struct drm_device *dev = prop->dev;
 	struct drm_atomic_state *state;
 	struct drm_modeset_acquire_ctx ctx;
 	int ret;

 	drm_modeset_acquire_init(&ctx, 0);

 	state = drm_atomic_state_alloc(dev);
 	if (!state)
 		return -ENOMEM;
 	state->acquire_ctx = &ctx;
 retry:
 	if (prop == state->dev->mode_config.dpms_property) {
 		if (obj->type != DRM_MODE_OBJECT_CONNECTOR) {
 			ret = -EINVAL;
 			goto out;
 		}

 		ret = drm_atomic_connector_commit_dpms(state,
 						       obj_to_connector(obj),
 						       prop_value);
 	} else {
 		ret = drm_atomic_set_property(state, obj, prop, prop_value);
 		if (ret)
 			goto out;
 		ret = drm_atomic_commit(state);
 	}
 out:
 	if (ret == -EDEADLK) {
 		drm_atomic_state_clear(state);
 		drm_modeset_backoff(&ctx);
 		goto retry;
 	}

 	drm_atomic_state_put(state);

 	drm_modeset_drop_locks(&ctx);
 	drm_modeset_acquire_fini(&ctx);

 	return ret;
 }

 int drm_mode_obj_set_property_ioctl(struct drm_device *dev, void *data,
 				    struct drm_file *file_priv)
 {
 	struct drm_mode_obj_set_property *arg = data;
 	struct drm_mode_object *arg_obj;
 	struct drm_property *property;
 	int ret = -EINVAL;

 	if (!drm_core_check_feature(dev, DRIVER_MODESET))
 		return -EINVAL;

 	arg_obj = drm_mode_object_find(dev, file_priv, arg->obj_id, arg->obj_type);
 	if (!arg_obj)
 		return -ENOENT;

 	if (!arg_obj->properties)
 		goto out_unref;

 	property = drm_mode_obj_find_prop_id(arg_obj, arg->prop_id);
 	if (!property)
 		goto out_unref;

 	if (drm_drv_uses_atomic_modeset(property->dev))
 		ret = set_property_atomic(arg_obj, property, arg->value);
 	else
 		ret = set_property_legacy(arg_obj, property, arg->value);

 out_unref:
 	drm_mode_object_put(arg_obj);
 	return ret;
 }
	/*
	* Copyright (c) 2016 Intel Corporation
	*
	* Permission to use, copy, modify, distribute, and sell this software and its
	* documentation for any purpose is hereby granted without fee, provided that
	* the above copyright notice appear in all copies and that both that copyright
	* notice and this permission notice appear in supporting documentation, and
	* that the name of the copyright holders not be used in advertising or
	* publicity pertaining to distribution of the software without specific,
	* written prior permission. The copyright holders make no representations
	* about the suitability of this software for any purpose. It is provided "as
	* is" without express or implied warranty.
	*
	* THE COPYRIGHT HOLDERS DISCLAIM ALL WARRANTIES WITH REGARD TO THIS SOFTWARE,
	* INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS, IN NO
	* EVENT SHALL THE COPYRIGHT HOLDERS BE LIABLE FOR ANY SPECIAL, INDIRECT OR
	* CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF USE,
	* DATA OR PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER
	* TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE
	* OF THIS SOFTWARE.
	*/

	#include <linux/export.h>
	#include <drm/drmP.h>
	#include <drm/drm_mode_object.h>
	#include <drm/drm_atomic.h>

	#include "drm_crtc_internal.h"

	/*
	* Internal function to assign a slot in the object idr and optionally
	* register the object into the idr.
	*/
	int __drm_mode_object_add(struct drm_device dev, struct drm_mode_object obj,
	uint32_t obj_type, bool register_obj,
	void (obj_free_cb)(struct kref kref))
	{
	int ret;

	mutex_lock(&dev->mode_config.idr_mutex);
	ret = idr_alloc(&dev->mode_config.crtc_idr, register_obj ? obj : NULL, 1, 0, GFP_KERNEL);
	if (ret >= 0) {
	/*
	* Set up the object linking under the protection of the idr
	* lock so that other users can't see inconsistent state.
	*/
	obj->id = ret;
	obj->type = obj_type;
	if (obj_free_cb) {
	obj->free_cb = obj_free_cb;
	kref_init(&obj->refcount);
	}
	}
	mutex_unlock(&dev->mode_config.idr_mutex);

	return ret < 0 ? ret : 0;
	}

	/**
	* drm_mode_object_add - allocate a new modeset identifier
	* @dev: DRM device
	* @obj: object pointer, used to generate unique ID
	* @obj_type: object type
	*
	* Create a unique identifier based on @ptr in @dev's identifier space. Used
	* for tracking modes, CRTCs and connectors.
	*
	* Returns:
	* Zero on success, error code on failure.
	*/
	int drm_mode_object_add(struct drm_device *dev,
	struct drm_mode_object *obj, uint32_t obj_type)
	{
	return __drm_mode_object_add(dev, obj, obj_type, true, NULL);
	}

	void drm_mode_object_register(struct drm_device *dev,
	struct drm_mode_object *obj)
	{
	mutex_lock(&dev->mode_config.idr_mutex);
	idr_replace(&dev->mode_config.crtc_idr, obj, obj->id);
	mutex_unlock(&dev->mode_config.idr_mutex);
	}

	/**
	* drm_mode_object_unregister - free a modeset identifer
	* @dev: DRM device
	* @object: object to free
	*
	* Free @id from @dev's unique identifier pool.
	* This function can be called multiple times, and guards against
	* multiple removals.
	* These modeset identifiers are _not_ reference counted. Hence don't use this
	* for reference counted modeset objects like framebuffers.
	*/
	void drm_mode_object_unregister(struct drm_device *dev,
	struct drm_mode_object *object)
	{
	mutex_lock(&dev->mode_config.idr_mutex);
	if (object->id) {
	idr_remove(&dev->mode_config.crtc_idr, object->id);
	object->id = 0;
	}
	mutex_unlock(&dev->mode_config.idr_mutex);
	}

	/**
	* drm_lease_required - check types which must be leased to be used
	* @type: type of object
	*
	* Returns whether the provided type of drm_mode_object must
	* be owned or leased to be used by a process.
	*/
	bool drm_mode_object_lease_required(uint32_t type)
	{
	switch(type) {
	case DRM_MODE_OBJECT_CRTC:
	case DRM_MODE_OBJECT_CONNECTOR:
	case DRM_MODE_OBJECT_PLANE:
	return true;
	default:
	return false;
	}
	}

	struct drm_mode_object __drm_mode_object_find(struct drm_device dev,
	struct drm_file *file_priv,
	uint32_t id, uint32_t type)
	{
	struct drm_mode_object *obj = NULL;

	mutex_lock(&dev->mode_config.idr_mutex);
	obj = idr_find(&dev->mode_config.crtc_idr, id);
	if (obj && type != DRM_MODE_OBJECT_ANY && obj->type != type)
	obj = NULL;
	if (obj && obj->id != id)
	obj = NULL;

	if (obj && drm_mode_object_lease_required(obj->type) &&
	!_drm_lease_held(file_priv, obj->id))
	obj = NULL;

	if (obj && obj->free_cb) {
	if (!kref_get_unless_zero(&obj->refcount))
	obj = NULL;
	}
	mutex_unlock(&dev->mode_config.idr_mutex);

	return obj;
	}

	/**
	* drm_mode_object_find - look up a drm object with static lifetime
	* @dev: drm device
	* @file_priv: drm file
	* @id: id of the mode object
	* @type: type of the mode object
	*
	* This function is used to look up a modeset object. It will acquire a
	* reference for reference counted objects. This reference must be dropped again
	* by callind drm_mode_object_put().
	*/
	struct drm_mode_object drm_mode_object_find(struct drm_device dev,
	struct drm_file *file_priv,
	uint32_t id, uint32_t type)
	{
	struct drm_mode_object *obj = NULL;

	obj = __drm_mode_object_find(dev, file_priv, id, type);
	return obj;
	}
	EXPORT_SYMBOL(drm_mode_object_find);

	/**
	* drm_mode_object_put - release a mode object reference
	* @obj: DRM mode object
	*
	* This function decrements the object's refcount if it is a refcounted modeset
	* object. It is a no-op on any other object. This is used to drop references
	* acquired with drm_mode_object_get().
	*/
	void drm_mode_object_put(struct drm_mode_object *obj)
	{
	if (obj->free_cb) {
	DRM_DEBUG("OBJ ID: %d (%d)\n", obj->id, kref_read(&obj->refcount));
	kref_put(&obj->refcount, obj->free_cb);
	}
	}
	EXPORT_SYMBOL(drm_mode_object_put);

	/**
	* drm_mode_object_get - acquire a mode object reference
	* @obj: DRM mode object
	*
	* This function increments the object's refcount if it is a refcounted modeset
	* object. It is a no-op on any other object. References should be dropped again
	* by calling drm_mode_object_put().
	*/
	void drm_mode_object_get(struct drm_mode_object *obj)
	{
	if (obj->free_cb) {
	DRM_DEBUG("OBJ ID: %d (%d)\n", obj->id, kref_read(&obj->refcount));
	kref_get(&obj->refcount);
	}
	}
	EXPORT_SYMBOL(drm_mode_object_get);

	/**
	* drm_object_attach_property - attach a property to a modeset object
	* @obj: drm modeset object
	* @property: property to attach
	* @init_val: initial value of the property
	*
	* This attaches the given property to the modeset object with the given initial
	* value. Currently this function cannot fail since the properties are stored in
	* a statically sized array.
	*/
	void drm_object_attach_property(struct drm_mode_object *obj,
	struct drm_property *property,
	uint64_t init_val)
	{
	int count = obj->properties->count;

	if (count == DRM_OBJECT_MAX_PROPERTY) {
	WARN(1, "Failed to attach object property (type: 0x%x). Please "
	"increase DRM_OBJECT_MAX_PROPERTY by 1 for each time "
	"you see this message on the same object type.\n",
	obj->type);
	return;
	}

	obj->properties->properties[count] = property;
	obj->properties->values[count] = init_val;
	obj->properties->count++;
	}
	EXPORT_SYMBOL(drm_object_attach_property);

	/**
	* drm_object_property_set_value - set the value of a property
	* @obj: drm mode object to set property value for
	* @property: property to set
	* @val: value the property should be set to
	*
	* This function sets a given property on a given object. This function only
	* changes the software state of the property, it does not call into the
	* driver's ->set_property callback.
	*
	* Note that atomic drivers should not have any need to call this, the core will
	* ensure consistency of values reported back to userspace through the
	* appropriate ->atomic_get_property callback. Only legacy drivers should call
	* this function to update the tracked value (after clamping and other
	* restrictions have been applied).
	*
	* Returns:
	* Zero on success, error code on failure.
	*/
	int drm_object_property_set_value(struct drm_mode_object *obj,
	struct drm_property *property, uint64_t val)
	{
	int i;

	WARN_ON(drm_drv_uses_atomic_modeset(property->dev) &&
	!(property->flags & DRM_MODE_PROP_IMMUTABLE));

	for (i = 0; i < obj->properties->count; i++) {
	if (obj->properties->properties[i] == property) {
	obj->properties->values[i] = val;
	return 0;
	}
	}

	return -EINVAL;
	}
	EXPORT_SYMBOL(drm_object_property_set_value);

	static int __drm_object_property_get_value(struct drm_mode_object *obj,
	struct drm_property *property,
	uint64_t *val)
	{
	int i;

	/* read-only properties bypass atomic mechanism and still store
	* their value in obj->properties->values[].. mostly to avoid
	* having to deal w/ EDID and similar props in atomic paths:
	*/
	if (drm_drv_uses_atomic_modeset(property->dev) &&
	!(property->flags & DRM_MODE_PROP_IMMUTABLE))
	return drm_atomic_get_property(obj, property, val);

	for (i = 0; i < obj->properties->count; i++) {
	if (obj->properties->properties[i] == property) {
	*val = obj->properties->values[i];
	return 0;
	}

	}

	return -EINVAL;
	}

	/**
	* drm_object_property_get_value - retrieve the value of a property
	* @obj: drm mode object to get property value from
	* @property: property to retrieve
	* @val: storage for the property value
	*
	* This function retrieves the softare state of the given property for the given
	* property. Since there is no driver callback to retrieve the current property
	* value this might be out of sync with the hardware, depending upon the driver
	* and property.
	*
	* Atomic drivers should never call this function directly, the core will read
	* out property values through the various ->atomic_get_property callbacks.
	*
	* Returns:
	* Zero on success, error code on failure.
	*/
	int drm_object_property_get_value(struct drm_mode_object *obj,
	struct drm_property property, uint64_t val)
	{
	WARN_ON(drm_drv_uses_atomic_modeset(property->dev));

	return __drm_object_property_get_value(obj, property, val);
	}
	EXPORT_SYMBOL(drm_object_property_get_value);

	/* helper for getconnector and getproperties ioctls */
	int drm_mode_object_get_properties(struct drm_mode_object *obj, bool atomic,
	uint32_t __user *prop_ptr,
	uint64_t __user *prop_values,
	uint32_t *arg_count_props)
	{
	int i, ret, count;

	for (i = 0, count = 0; i < obj->properties->count; i++) {
	struct drm_property *prop = obj->properties->properties[i];
	uint64_t val;

	if ((prop->flags & DRM_MODE_PROP_ATOMIC) && !atomic)
	continue;

	if (*arg_count_props > count) {
	ret = __drm_object_property_get_value(obj, prop, &val);
	if (ret)
	return ret;

	if (put_user(prop->base.id, prop_ptr + count))
	return -EFAULT;

	if (put_user(val, prop_values + count))
	return -EFAULT;
	}

	count++;
	}
	*arg_count_props = count;

	return 0;
	}

	/**
	* drm_mode_obj_get_properties_ioctl - get the current value of a object's property
	* @dev: DRM device
	* @data: ioctl data
	* @file_priv: DRM file info
	*
	* This function retrieves the current value for an object's property. Compared
	* to the connector specific ioctl this one is extended to also work on crtc and
	* plane objects.
	*
	* Called by the user via ioctl.
	*
	* Returns:
	* Zero on success, negative errno on failure.
	*/
	int drm_mode_obj_get_properties_ioctl(struct drm_device dev, void data,
	struct drm_file *file_priv)
	{
	struct drm_mode_obj_get_properties *arg = data;
	struct drm_mode_object *obj;
	int ret = 0;

	if (!drm_core_check_feature(dev, DRIVER_MODESET))
	return -EINVAL;

	drm_modeset_lock_all(dev);

	obj = drm_mode_object_find(dev, file_priv, arg->obj_id, arg->obj_type);
	if (!obj) {
	ret = -ENOENT;
	goto out;
	}
	if (!obj->properties) {
	ret = -EINVAL;
	goto out_unref;
	}

	ret = drm_mode_object_get_properties(obj, file_priv->atomic,
	(uint32_t __user *)(unsigned long)(arg->props_ptr),
	(uint64_t __user *)(unsigned long)(arg->prop_values_ptr),
	&arg->count_props);

	out_unref:
	drm_mode_object_put(obj);
	out:
	drm_modeset_unlock_all(dev);
	return ret;
	}

	struct drm_property drm_mode_obj_find_prop_id(struct drm_mode_object obj,
	uint32_t prop_id)
	{
	int i;

	for (i = 0; i < obj->properties->count; i++)
	if (obj->properties->properties[i]->base.id == prop_id)
	return obj->properties->properties[i];

	return NULL;
	}

	static int set_property_legacy(struct drm_mode_object *obj,
	struct drm_property *prop,
	uint64_t prop_value)
	{
	struct drm_device *dev = prop->dev;
	struct drm_mode_object *ref;
	int ret = -EINVAL;

	if (!drm_property_change_valid_get(prop, prop_value, &ref))
	return -EINVAL;

	drm_modeset_lock_all(dev);
	switch (obj->type) {
	case DRM_MODE_OBJECT_CONNECTOR:
	ret = drm_mode_connector_set_obj_prop(obj, prop,
	prop_value);
	break;
	case DRM_MODE_OBJECT_CRTC:
	ret = drm_mode_crtc_set_obj_prop(obj, prop, prop_value);
	break;
	case DRM_MODE_OBJECT_PLANE:
	ret = drm_mode_plane_set_obj_prop(obj_to_plane(obj),
	prop, prop_value);
	break;
	}
	drm_property_change_valid_put(prop, ref);
	drm_modeset_unlock_all(dev);

	return ret;
	}

	static int set_property_atomic(struct drm_mode_object *obj,
	struct drm_property *prop,
	uint64_t prop_value)
	{
	struct drm_device *dev = prop->dev;
	struct drm_atomic_state *state;
	struct drm_modeset_acquire_ctx ctx;
	int ret;

	drm_modeset_acquire_init(&ctx, 0);

	state = drm_atomic_state_alloc(dev);
	if (!state)
	return -ENOMEM;
	state->acquire_ctx = &ctx;
	retry:
	if (prop == state->dev->mode_config.dpms_property) {
	if (obj->type != DRM_MODE_OBJECT_CONNECTOR) {
	ret = -EINVAL;
	goto out;
	}

	ret = drm_atomic_connector_commit_dpms(state,
	obj_to_connector(obj),
	prop_value);
	} else {
	ret = drm_atomic_set_property(state, obj, prop, prop_value);
	if (ret)
	goto out;
	ret = drm_atomic_commit(state);
	}
	out:
	if (ret == -EDEADLK) {
	drm_atomic_state_clear(state);
	drm_modeset_backoff(&ctx);
	goto retry;
	}

	drm_atomic_state_put(state);

	drm_modeset_drop_locks(&ctx);
	drm_modeset_acquire_fini(&ctx);

	return ret;
	}

	int drm_mode_obj_set_property_ioctl(struct drm_device dev, void data,
	struct drm_file *file_priv)
	{
	struct drm_mode_obj_set_property *arg = data;
	struct drm_mode_object *arg_obj;
	struct drm_property *property;
	int ret = -EINVAL;

	if (!drm_core_check_feature(dev, DRIVER_MODESET))
	return -EINVAL;

	arg_obj = drm_mode_object_find(dev, file_priv, arg->obj_id, arg->obj_type);
	if (!arg_obj)
	return -ENOENT;

	if (!arg_obj->properties)
	goto out_unref;

	property = drm_mode_obj_find_prop_id(arg_obj, arg->prop_id);
	if (!property)
	goto out_unref;

	if (drm_drv_uses_atomic_modeset(property->dev))
	ret = set_property_atomic(arg_obj, property, arg->value);
	else
	ret = set_property_legacy(arg_obj, property, arg->value);

	out_unref:
	drm_mode_object_put(arg_obj);
	return ret;
	}