text: /*
   * 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 <linux/uaccess.h>
  
  #include <drm/drm_atomic.h>
  #include <drm/drm_drv.h>
  #include <drm/drm_device.h>
  #include <drm/drm_file.h>
  #include <drm/drm_mode_object.h>
  #include <drm/drm_print.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;
  
  	WARN_ON(!dev->driver->load && dev->registered && !obj_free_cb);
  
  	mutex_lock(&dev->mode_config.idr_mutex);
  	ret = idr_alloc(&dev->mode_config.object_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.object_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)
  {
  	WARN_ON(!dev->driver->load && dev->registered && !object->free_cb);
  
  	mutex_lock(&dev->mode_config.idr_mutex);
  	if (object->id) {
  		idr_remove(&dev->mode_config.object_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.object_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.
   *
   * Note that all properties must be attached before the object itself is
   * registered and accessible from userspace.
   */
  void drm_object_attach_property(struct drm_mode_object *obj,
  				struct drm_property *property,
  				uint64_t init_val)
  {
  	int count = obj->properties->count;
  	struct drm_device *dev = property->dev;
  
  
  	if (obj->type == DRM_MODE_OBJECT_CONNECTOR) {
  		struct drm_connector *connector = obj_to_connector(obj);
  
  		WARN_ON(!dev->driver->load &&
  			connector->registration_state == DRM_CONNECTOR_REGISTERED);
  	} else {
  		WARN_ON(!dev->driver->load && dev->registered);
  	}
  
  	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 -EOPNOTSUPP;
  
  	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_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_file *file_priv,
  			       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;
  
  	state = drm_atomic_state_alloc(dev);
  	if (!state)
  		return -ENOMEM;
  
  	drm_modeset_acquire_init(&ctx, 0);
  	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, file_priv, 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 -EOPNOTSUPP;
  
  	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, file_priv, property, arg->value);
  	else
  		ret = set_property_legacy(arg_obj, property, arg->value);
  
  out_unref:
  	drm_mode_object_put(arg_obj);
  	return ret;
  }
  