Adding upstream version 6.1.76.upstream/6.1.76upstream

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 729 insertions, 0 deletions

diff --git a/drivers/gpu/drm/drm_lease.c b/drivers/gpu/drm/drm_lease.c
new file mode 100644
index 000000000..b7362356e
--- /dev/null
+++ b/drivers/gpu/drm/drm_lease.c
@@ -0,0 +1,729 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ * Copyright © 2017 Keith Packard <keithp@keithp.com>
+ */
+#include <linux/file.h>
+#include <linux/uaccess.h>
+
+#include <drm/drm_auth.h>
+#include <drm/drm_crtc_helper.h>
+#include <drm/drm_drv.h>
+#include <drm/drm_file.h>
+#include <drm/drm_lease.h>
+#include <drm/drm_print.h>
+
+#include "drm_crtc_internal.h"
+#include "drm_internal.h"
+
+/**
+ * DOC: drm leasing
+ *
+ * DRM leases provide information about whether a DRM master may control a DRM
+ * mode setting object. This enables the creation of multiple DRM masters that
+ * manage subsets of display resources.
+ *
+ * The original DRM master of a device 'owns' the available drm resources. It
+ * may create additional DRM masters and 'lease' resources which it controls
+ * to the new DRM master. This gives the new DRM master control over the
+ * leased resources until the owner revokes the lease, or the new DRM master
+ * is closed. Some helpful terminology:
+ *
+ * - An 'owner' is a &struct drm_master that is not leasing objects from
+ *   another &struct drm_master, and hence 'owns' the objects. The owner can be
+ *   identified as the &struct drm_master for which &drm_master.lessor is NULL.
+ *
+ * - A 'lessor' is a &struct drm_master which is leasing objects to one or more
+ *   other &struct drm_master. Currently, lessees are not allowed to
+ *   create sub-leases, hence the lessor is the same as the owner.
+ *
+ * - A 'lessee' is a &struct drm_master which is leasing objects from some
+ *   other &struct drm_master. Each lessee only leases resources from a single
+ *   lessor recorded in &drm_master.lessor, and holds the set of objects that
+ *   it is leasing in &drm_master.leases.
+ *
+ * - A 'lease' is a contract between the lessor and lessee that identifies
+ *   which resources may be controlled by the lessee. All of the resources
+ *   that are leased must be owned by or leased to the lessor, and lessors are
+ *   not permitted to lease the same object to multiple lessees.
+ *
+ * The set of objects any &struct drm_master 'controls' is limited to the set
+ * of objects it leases (for lessees) or all objects (for owners).
+ *
+ * Objects not controlled by a &struct drm_master cannot be modified through
+ * the various state manipulating ioctls, and any state reported back to user
+ * space will be edited to make them appear idle and/or unusable. For
+ * instance, connectors always report 'disconnected', while encoders
+ * report no possible crtcs or clones.
+ *
+ * Since each lessee may lease objects from a single lessor, display resource
+ * leases form a tree of &struct drm_master. As lessees are currently not
+ * allowed to create sub-leases, the tree depth is limited to 1. All of
+ * these get activated simultaneously when the top level device owner changes
+ * through the SETMASTER or DROPMASTER IOCTL, so &drm_device.master points to
+ * the owner at the top of the lease tree (i.e. the &struct drm_master for which
+ * &drm_master.lessor is NULL). The full list of lessees that are leasing
+ * objects from the owner can be searched via the owner's
+ * &drm_master.lessee_idr.
+ */
+
+#define drm_for_each_lessee(lessee, lessor) \
+	list_for_each_entry((lessee), &(lessor)->lessees, lessee_list)
+
+static uint64_t drm_lease_idr_object;
+
+struct drm_master *drm_lease_owner(struct drm_master *master)
+{
+	while (master->lessor != NULL)
+		master = master->lessor;
+	return master;
+}
+
+static struct drm_master*
+_drm_find_lessee(struct drm_master *master, int lessee_id)
+{
+	lockdep_assert_held(&master->dev->mode_config.idr_mutex);
+	return idr_find(&drm_lease_owner(master)->lessee_idr, lessee_id);
+}
+
+static int _drm_lease_held_master(struct drm_master *master, int id)
+{
+	lockdep_assert_held(&master->dev->mode_config.idr_mutex);
+	if (master->lessor)
+		return idr_find(&master->leases, id) != NULL;
+	return true;
+}
+
+/* Checks if the given object has been leased to some lessee of drm_master */
+static bool _drm_has_leased(struct drm_master *master, int id)
+{
+	struct drm_master *lessee;
+
+	lockdep_assert_held(&master->dev->mode_config.idr_mutex);
+	drm_for_each_lessee(lessee, master)
+		if (_drm_lease_held_master(lessee, id))
+			return true;
+	return false;
+}
+
+/* Called with idr_mutex held */
+bool _drm_lease_held(struct drm_file *file_priv, int id)
+{
+	bool ret;
+	struct drm_master *master;
+
+	if (!file_priv)
+		return true;
+
+	master = drm_file_get_master(file_priv);
+	if (!master)
+		return true;
+	ret = _drm_lease_held_master(master, id);
+	drm_master_put(&master);
+
+	return ret;
+}
+
+bool drm_lease_held(struct drm_file *file_priv, int id)
+{
+	struct drm_master *master;
+	bool ret;
+
+	if (!file_priv)
+		return true;
+
+	master = drm_file_get_master(file_priv);
+	if (!master)
+		return true;
+	if (!master->lessor) {
+		ret = true;
+		goto out;
+	}
+	mutex_lock(&master->dev->mode_config.idr_mutex);
+	ret = _drm_lease_held_master(master, id);
+	mutex_unlock(&master->dev->mode_config.idr_mutex);
+
+out:
+	drm_master_put(&master);
+	return ret;
+}
+
+/*
+ * Given a bitmask of crtcs to check, reconstructs a crtc mask based on the
+ * crtcs which are visible through the specified file.
+ */
+uint32_t drm_lease_filter_crtcs(struct drm_file *file_priv, uint32_t crtcs_in)
+{
+	struct drm_master *master;
+	struct drm_device *dev;
+	struct drm_crtc *crtc;
+	int count_in, count_out;
+	uint32_t crtcs_out = 0;
+
+	if (!file_priv)
+		return crtcs_in;
+
+	master = drm_file_get_master(file_priv);
+	if (!master)
+		return crtcs_in;
+	if (!master->lessor) {
+		crtcs_out = crtcs_in;
+		goto out;
+	}
+	dev = master->dev;
+
+	count_in = count_out = 0;
+	mutex_lock(&master->dev->mode_config.idr_mutex);
+	list_for_each_entry(crtc, &dev->mode_config.crtc_list, head) {
+		if (_drm_lease_held_master(master, crtc->base.id)) {
+			uint32_t mask_in = 1ul << count_in;
+
+			if ((crtcs_in & mask_in) != 0) {
+				uint32_t mask_out = 1ul << count_out;
+
+				crtcs_out |= mask_out;
+			}
+			count_out++;
+		}
+		count_in++;
+	}
+	mutex_unlock(&master->dev->mode_config.idr_mutex);
+
+out:
+	drm_master_put(&master);
+	return crtcs_out;
+}
+
+/*
+ * Uses drm_master_create to allocate a new drm_master, then checks to
+ * make sure all of the desired objects can be leased, atomically
+ * leasing them to the new drmmaster.
+ *
+ * 	ERR_PTR(-EACCES)	some other master holds the title to any object
+ * 	ERR_PTR(-ENOENT)	some object is not a valid DRM object for this device
+ * 	ERR_PTR(-EBUSY)		some other lessee holds title to this object
+ *	ERR_PTR(-EEXIST)	same object specified more than once in the provided list
+ *	ERR_PTR(-ENOMEM)	allocation failed
+ */
+static struct drm_master *drm_lease_create(struct drm_master *lessor, struct idr *leases)
+{
+	struct drm_device *dev = lessor->dev;
+	int error;
+	struct drm_master *lessee;
+	int object;
+	int id;
+	void *entry;
+
+	DRM_DEBUG_LEASE("lessor %d\n", lessor->lessee_id);
+
+	lessee = drm_master_create(lessor->dev);
+	if (!lessee) {
+		DRM_DEBUG_LEASE("drm_master_create failed\n");
+		return ERR_PTR(-ENOMEM);
+	}
+
+	mutex_lock(&dev->mode_config.idr_mutex);
+
+	idr_for_each_entry(leases, entry, object) {
+		error = 0;
+		if (!idr_find(&dev->mode_config.object_idr, object))
+			error = -ENOENT;
+		else if (_drm_has_leased(lessor, object))
+			error = -EBUSY;
+
+		if (error != 0) {
+			DRM_DEBUG_LEASE("object %d failed %d\n", object, error);
+			goto out_lessee;
+		}
+	}
+
+	/* Insert the new lessee into the tree */
+	id = idr_alloc(&(drm_lease_owner(lessor)->lessee_idr), lessee, 1, 0, GFP_KERNEL);
+	if (id < 0) {
+		error = id;
+		goto out_lessee;
+	}
+
+	lessee->lessee_id = id;
+	lessee->lessor = drm_master_get(lessor);
+	list_add_tail(&lessee->lessee_list, &lessor->lessees);
+
+	/* Move the leases over */
+	lessee->leases = *leases;
+	DRM_DEBUG_LEASE("new lessee %d %p, lessor %d %p\n", lessee->lessee_id, lessee, lessor->lessee_id, lessor);
+
+	mutex_unlock(&dev->mode_config.idr_mutex);
+	return lessee;
+
+out_lessee:
+	mutex_unlock(&dev->mode_config.idr_mutex);
+
+	drm_master_put(&lessee);
+
+	return ERR_PTR(error);
+}
+
+void drm_lease_destroy(struct drm_master *master)
+{
+	struct drm_device *dev = master->dev;
+
+	mutex_lock(&dev->mode_config.idr_mutex);
+
+	DRM_DEBUG_LEASE("drm_lease_destroy %d\n", master->lessee_id);
+
+	/* This master is referenced by all lessees, hence it cannot be destroyed
+	 * until all of them have been
+	 */
+	WARN_ON(!list_empty(&master->lessees));
+
+	/* Remove this master from the lessee idr in the owner */
+	if (master->lessee_id != 0) {
+		DRM_DEBUG_LEASE("remove master %d from device list of lessees\n", master->lessee_id);
+		idr_remove(&(drm_lease_owner(master)->lessee_idr), master->lessee_id);
+	}
+
+	/* Remove this master from any lessee list it may be on */
+	list_del(&master->lessee_list);
+
+	mutex_unlock(&dev->mode_config.idr_mutex);
+
+	if (master->lessor) {
+		/* Tell the master to check the lessee list */
+		drm_sysfs_lease_event(dev);
+		drm_master_put(&master->lessor);
+	}
+
+	DRM_DEBUG_LEASE("drm_lease_destroy done %d\n", master->lessee_id);
+}
+
+static void _drm_lease_revoke(struct drm_master *top)
+{
+	int object;
+	void *entry;
+	struct drm_master *master = top;
+
+	lockdep_assert_held(&top->dev->mode_config.idr_mutex);
+
+	/*
+	 * Walk the tree starting at 'top' emptying all leases. Because
+	 * the tree is fully connected, we can do this without recursing
+	 */
+	for (;;) {
+		DRM_DEBUG_LEASE("revoke leases for %p %d\n", master, master->lessee_id);
+
+		/* Evacuate the lease */
+		idr_for_each_entry(&master->leases, entry, object)
+			idr_remove(&master->leases, object);
+
+		/* Depth-first list walk */
+
+		/* Down */
+		if (!list_empty(&master->lessees)) {
+			master = list_first_entry(&master->lessees, struct drm_master, lessee_list);
+		} else {
+			/* Up */
+			while (master != top && master == list_last_entry(&master->lessor->lessees, struct drm_master, lessee_list))
+				master = master->lessor;
+
+			if (master == top)
+				break;
+
+			/* Over */
+			master = list_next_entry(master, lessee_list);
+		}
+	}
+}
+
+void drm_lease_revoke(struct drm_master *top)
+{
+	mutex_lock(&top->dev->mode_config.idr_mutex);
+	_drm_lease_revoke(top);
+	mutex_unlock(&top->dev->mode_config.idr_mutex);
+}
+
+static int validate_lease(struct drm_device *dev,
+			  int object_count,
+			  struct drm_mode_object **objects,
+			  bool universal_planes)
+{
+	int o;
+	int has_crtc = -1;
+	int has_connector = -1;
+	int has_plane = -1;
+
+	/* we want to confirm that there is at least one crtc, plane
+	   connector object. */
+
+	for (o = 0; o < object_count; o++) {
+		if (objects[o]->type == DRM_MODE_OBJECT_CRTC && has_crtc == -1) {
+			has_crtc = o;
+		}
+		if (objects[o]->type == DRM_MODE_OBJECT_CONNECTOR && has_connector == -1)
+			has_connector = o;
+
+		if (universal_planes) {
+			if (objects[o]->type == DRM_MODE_OBJECT_PLANE && has_plane == -1)
+				has_plane = o;
+		}
+	}
+	if (has_crtc == -1 || has_connector == -1)
+		return -EINVAL;
+	if (universal_planes && has_plane == -1)
+		return -EINVAL;
+	return 0;
+}
+
+static int fill_object_idr(struct drm_device *dev,
+			   struct drm_file *lessor_priv,
+			   struct idr *leases,
+			   int object_count,
+			   u32 *object_ids)
+{
+	struct drm_mode_object **objects;
+	u32 o;
+	int ret;
+	bool universal_planes = READ_ONCE(lessor_priv->universal_planes);
+
+	objects = kcalloc(object_count, sizeof(struct drm_mode_object *),
+			  GFP_KERNEL);
+	if (!objects)
+		return -ENOMEM;
+
+	/* step one - get references to all the mode objects
+	   and check for validity. */
+	for (o = 0; o < object_count; o++) {
+		objects[o] = drm_mode_object_find(dev, lessor_priv,
+						  object_ids[o],
+						  DRM_MODE_OBJECT_ANY);
+		if (!objects[o]) {
+			ret = -ENOENT;
+			goto out_free_objects;
+		}
+
+		if (!drm_mode_object_lease_required(objects[o]->type)) {
+			DRM_DEBUG_KMS("invalid object for lease\n");
+			ret = -EINVAL;
+			goto out_free_objects;
+		}
+	}
+
+	ret = validate_lease(dev, object_count, objects, universal_planes);
+	if (ret) {
+		DRM_DEBUG_LEASE("lease validation failed\n");
+		goto out_free_objects;
+	}
+
+	/* add their IDs to the lease request - taking into account
+	   universal planes */
+	for (o = 0; o < object_count; o++) {
+		struct drm_mode_object *obj = objects[o];
+		u32 object_id = objects[o]->id;
+
+		DRM_DEBUG_LEASE("Adding object %d to lease\n", object_id);
+
+		/*
+		 * We're using an IDR to hold the set of leased
+		 * objects, but we don't need to point at the object's
+		 * data structure from the lease as the main object_idr
+		 * will be used to actually find that. Instead, all we
+		 * really want is a 'leased/not-leased' result, for
+		 * which any non-NULL pointer will work fine.
+		 */
+		ret = idr_alloc(leases, &drm_lease_idr_object , object_id, object_id + 1, GFP_KERNEL);
+		if (ret < 0) {
+			DRM_DEBUG_LEASE("Object %d cannot be inserted into leases (%d)\n",
+					object_id, ret);
+			goto out_free_objects;
+		}
+		if (obj->type == DRM_MODE_OBJECT_CRTC && !universal_planes) {
+			struct drm_crtc *crtc = obj_to_crtc(obj);
+
+			ret = idr_alloc(leases, &drm_lease_idr_object, crtc->primary->base.id, crtc->primary->base.id + 1, GFP_KERNEL);
+			if (ret < 0) {
+				DRM_DEBUG_LEASE("Object primary plane %d cannot be inserted into leases (%d)\n",
+						object_id, ret);
+				goto out_free_objects;
+			}
+			if (crtc->cursor) {
+				ret = idr_alloc(leases, &drm_lease_idr_object, crtc->cursor->base.id, crtc->cursor->base.id + 1, GFP_KERNEL);
+				if (ret < 0) {
+					DRM_DEBUG_LEASE("Object cursor plane %d cannot be inserted into leases (%d)\n",
+							object_id, ret);
+					goto out_free_objects;
+				}
+			}
+		}
+	}
+
+	ret = 0;
+out_free_objects:
+	for (o = 0; o < object_count; o++) {
+		if (objects[o])
+			drm_mode_object_put(objects[o]);
+	}
+	kfree(objects);
+	return ret;
+}
+
+/*
+ * The master associated with the specified file will have a lease
+ * created containing the objects specified in the ioctl structure.
+ * A file descriptor will be allocated for that and returned to the
+ * application.
+ */
+int drm_mode_create_lease_ioctl(struct drm_device *dev,
+				void *data, struct drm_file *lessor_priv)
+{
+	struct drm_mode_create_lease *cl = data;
+	size_t object_count;
+	int ret = 0;
+	struct idr leases;
+	struct drm_master *lessor;
+	struct drm_master *lessee = NULL;
+	struct file *lessee_file = NULL;
+	struct file *lessor_file = lessor_priv->filp;
+	struct drm_file *lessee_priv;
+	int fd = -1;
+	uint32_t *object_ids;
+
+	/* Can't lease without MODESET */
+	if (!drm_core_check_feature(dev, DRIVER_MODESET))
+		return -EOPNOTSUPP;
+
+	if (cl->flags && (cl->flags & ~(O_CLOEXEC | O_NONBLOCK))) {
+		DRM_DEBUG_LEASE("invalid flags\n");
+		return -EINVAL;
+	}
+
+	lessor = drm_file_get_master(lessor_priv);
+	/* Do not allow sub-leases */
+	if (lessor->lessor) {
+		DRM_DEBUG_LEASE("recursive leasing not allowed\n");
+		ret = -EINVAL;
+		goto out_lessor;
+	}
+
+	object_count = cl->object_count;
+
+	/* Handle leased objects, if any */
+	idr_init(&leases);
+	if (object_count != 0) {
+		object_ids = memdup_array_user(u64_to_user_ptr(cl->object_ids),
+					       object_count, sizeof(__u32));
+		if (IS_ERR(object_ids)) {
+			ret = PTR_ERR(object_ids);
+			idr_destroy(&leases);
+			goto out_lessor;
+		}
+
+		/* fill and validate the object idr */
+		ret = fill_object_idr(dev, lessor_priv, &leases,
+				      object_count, object_ids);
+		kfree(object_ids);
+		if (ret) {
+			DRM_DEBUG_LEASE("lease object lookup failed: %i\n", ret);
+			idr_destroy(&leases);
+			goto out_lessor;
+		}
+	}
+
+	/* Allocate a file descriptor for the lease */
+	fd = get_unused_fd_flags(cl->flags & (O_CLOEXEC | O_NONBLOCK));
+	if (fd < 0) {
+		idr_destroy(&leases);
+		ret = fd;
+		goto out_lessor;
+	}
+
+	DRM_DEBUG_LEASE("Creating lease\n");
+	/* lessee will take the ownership of leases */
+	lessee = drm_lease_create(lessor, &leases);
+
+	if (IS_ERR(lessee)) {
+		ret = PTR_ERR(lessee);
+		idr_destroy(&leases);
+		goto out_leases;
+	}
+
+	/* Clone the lessor file to create a new file for us */
+	DRM_DEBUG_LEASE("Allocating lease file\n");
+	lessee_file = file_clone_open(lessor_file);
+	if (IS_ERR(lessee_file)) {
+		ret = PTR_ERR(lessee_file);
+		goto out_lessee;
+	}
+
+	lessee_priv = lessee_file->private_data;
+	/* Change the file to a master one */
+	drm_master_put(&lessee_priv->master);
+	lessee_priv->master = lessee;
+	lessee_priv->is_master = 1;
+	lessee_priv->authenticated = 1;
+
+	/* Pass fd back to userspace */
+	DRM_DEBUG_LEASE("Returning fd %d id %d\n", fd, lessee->lessee_id);
+	cl->fd = fd;
+	cl->lessee_id = lessee->lessee_id;
+
+	/* Hook up the fd */
+	fd_install(fd, lessee_file);
+
+	drm_master_put(&lessor);
+	DRM_DEBUG_LEASE("drm_mode_create_lease_ioctl succeeded\n");
+	return 0;
+
+out_lessee:
+	drm_master_put(&lessee);
+
+out_leases:
+	put_unused_fd(fd);
+
+out_lessor:
+	drm_master_put(&lessor);
+	DRM_DEBUG_LEASE("drm_mode_create_lease_ioctl failed: %d\n", ret);
+	return ret;
+}
+
+int drm_mode_list_lessees_ioctl(struct drm_device *dev,
+			       void *data, struct drm_file *lessor_priv)
+{
+	struct drm_mode_list_lessees *arg = data;
+	__u32 __user *lessee_ids = (__u32 __user *) (uintptr_t) (arg->lessees_ptr);
+	__u32 count_lessees = arg->count_lessees;
+	struct drm_master *lessor, *lessee;
+	int count;
+	int ret = 0;
+
+	if (arg->pad)
+		return -EINVAL;
+
+	/* Can't lease without MODESET */
+	if (!drm_core_check_feature(dev, DRIVER_MODESET))
+		return -EOPNOTSUPP;
+
+	lessor = drm_file_get_master(lessor_priv);
+	DRM_DEBUG_LEASE("List lessees for %d\n", lessor->lessee_id);
+
+	mutex_lock(&dev->mode_config.idr_mutex);
+
+	count = 0;
+	drm_for_each_lessee(lessee, lessor) {
+		/* Only list un-revoked leases */
+		if (!idr_is_empty(&lessee->leases)) {
+			if (count_lessees > count) {
+				DRM_DEBUG_LEASE("Add lessee %d\n", lessee->lessee_id);
+				ret = put_user(lessee->lessee_id, lessee_ids + count);
+				if (ret)
+					break;
+			}
+			count++;
+		}
+	}
+
+	DRM_DEBUG_LEASE("Lessor leases to %d\n", count);
+	if (ret == 0)
+		arg->count_lessees = count;
+
+	mutex_unlock(&dev->mode_config.idr_mutex);
+	drm_master_put(&lessor);
+
+	return ret;
+}
+
+/* Return the list of leased objects for the specified lessee */
+int drm_mode_get_lease_ioctl(struct drm_device *dev,
+			     void *data, struct drm_file *lessee_priv)
+{
+	struct drm_mode_get_lease *arg = data;
+	__u32 __user *object_ids = (__u32 __user *) (uintptr_t) (arg->objects_ptr);
+	__u32 count_objects = arg->count_objects;
+	struct drm_master *lessee;
+	struct idr *object_idr;
+	int count;
+	void *entry;
+	int object;
+	int ret = 0;
+
+	if (arg->pad)
+		return -EINVAL;
+
+	/* Can't lease without MODESET */
+	if (!drm_core_check_feature(dev, DRIVER_MODESET))
+		return -EOPNOTSUPP;
+
+	lessee = drm_file_get_master(lessee_priv);
+	DRM_DEBUG_LEASE("get lease for %d\n", lessee->lessee_id);
+
+	mutex_lock(&dev->mode_config.idr_mutex);
+
+	if (lessee->lessor == NULL)
+		/* owner can use all objects */
+		object_idr = &lessee->dev->mode_config.object_idr;
+	else
+		/* lessee can only use allowed object */
+		object_idr = &lessee->leases;
+
+	count = 0;
+	idr_for_each_entry(object_idr, entry, object) {
+		if (count_objects > count) {
+			DRM_DEBUG_LEASE("adding object %d\n", object);
+			ret = put_user(object, object_ids + count);
+			if (ret)
+				break;
+		}
+		count++;
+	}
+
+	DRM_DEBUG("lease holds %d objects\n", count);
+	if (ret == 0)
+		arg->count_objects = count;
+
+	mutex_unlock(&dev->mode_config.idr_mutex);
+	drm_master_put(&lessee);
+
+	return ret;
+}
+
+/*
+ * This removes all of the objects from the lease without
+ * actually getting rid of the lease itself; that way all
+ * references to it still work correctly
+ */
+int drm_mode_revoke_lease_ioctl(struct drm_device *dev,
+				void *data, struct drm_file *lessor_priv)
+{
+	struct drm_mode_revoke_lease *arg = data;
+	struct drm_master *lessor;
+	struct drm_master *lessee;
+	int ret = 0;
+
+	DRM_DEBUG_LEASE("revoke lease for %d\n", arg->lessee_id);
+
+	/* Can't lease without MODESET */
+	if (!drm_core_check_feature(dev, DRIVER_MODESET))
+		return -EOPNOTSUPP;
+
+	lessor = drm_file_get_master(lessor_priv);
+	mutex_lock(&dev->mode_config.idr_mutex);
+
+	lessee = _drm_find_lessee(lessor, arg->lessee_id);
+
+	/* No such lessee */
+	if (!lessee) {
+		ret = -ENOENT;
+		goto fail;
+	}
+
+	/* Lease is not held by lessor */
+	if (lessee->lessor != lessor) {
+		ret = -EACCES;
+		goto fail;
+	}
+
+	_drm_lease_revoke(lessee);
+
+fail:
+	mutex_unlock(&dev->mode_config.idr_mutex);
+	drm_master_put(&lessor);
+
+	return ret;
+}