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-rw-r--r--drivers/gpu/drm/drm_lease.c729
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;
+}