1 // SPDX-License-Identifier: GPL-2.0-or-later
21  * DRM leases provide information about whether a DRM master may control a DRM
25  * The original DRM master of a device 'owns' the available drm resources. It
27  * to the new DRM master. This gives the new DRM master control over the
28  * leased resources until the owner revokes the lease, or the new DRM master
31  * - An 'owner' is a &struct drm_master that is not leasing objects from
35  * - A 'lessor' is a &struct drm_master which is leasing objects to one or more
37  *   create sub-leases, hence the lessor is the same as the owner.
39  * - A 'lessee' is a &struct drm_master which is leasing objects from some
40  *   other &struct drm_master. Each lessee only leases resources from a single
44  * - A 'lease' is a contract between the lessor and lessee that identifies
58  * Since each lessee may lease objects from a single lessor, display resource
60  * allowed to create sub-leases, the tree depth is limited to 1. All of
62  * through the SETMASTER or DROPMASTER IOCTL, so &drm_device.master points to
70 	list_for_each_entry((lessee), &(lessor)->lessees, lessee_list)
74 struct drm_master *drm_lease_owner(struct drm_master *master)  in drm_lease_owner()  argument
76 	while (master->lessor != NULL)  in drm_lease_owner()
77 		master = master->lessor;  in drm_lease_owner()
78 	return master;  in drm_lease_owner()
82 _drm_find_lessee(struct drm_master *master, int lessee_id)  in _drm_find_lessee()  argument
84 	lockdep_assert_held(&master->dev->mode_config.idr_mutex);  in _drm_find_lessee()
85 	return idr_find(&drm_lease_owner(master)->lessee_idr, lessee_id);  in _drm_find_lessee()
88 static int _drm_lease_held_master(struct drm_master *master, int id)  in _drm_lease_held_master()  argument
90 	lockdep_assert_held(&master->dev->mode_config.idr_mutex);  in _drm_lease_held_master()
91 	if (master->lessor)  in _drm_lease_held_master()
92 		return idr_find(&master->leases, id) != NULL;  in _drm_lease_held_master()
97 static bool _drm_has_leased(struct drm_master *master, int id)  in _drm_has_leased()  argument
101 	lockdep_assert_held(&master->dev->mode_config.idr_mutex);  in _drm_has_leased()
102 	drm_for_each_lessee(lessee, master)  in _drm_has_leased()
112 	struct drm_master *master;  in _drm_lease_held()  local
117 	master = drm_file_get_master(file_priv);  in _drm_lease_held()
118 	if (!master)  in _drm_lease_held()
120 	ret = _drm_lease_held_master(master, id);  in _drm_lease_held()
121 	drm_master_put(&master);  in _drm_lease_held()
128 	struct drm_master *master;  in drm_lease_held()  local
134 	master = drm_file_get_master(file_priv);  in drm_lease_held()
135 	if (!master)  in drm_lease_held()
137 	if (!master->lessor) {  in drm_lease_held()
141 	mutex_lock(&master->dev->mode_config.idr_mutex);  in drm_lease_held()
142 	ret = _drm_lease_held_master(master, id);  in drm_lease_held()
143 	mutex_unlock(&master->dev->mode_config.idr_mutex);  in drm_lease_held()
146 	drm_master_put(&master);  in drm_lease_held()
156 	struct drm_master *master;  in drm_lease_filter_crtcs()  local
165 	master = drm_file_get_master(file_priv);  in drm_lease_filter_crtcs()
166 	if (!master)  in drm_lease_filter_crtcs()
168 	if (!master->lessor) {  in drm_lease_filter_crtcs()
172 	dev = master->dev;  in drm_lease_filter_crtcs()
175 	mutex_lock(&master->dev->mode_config.idr_mutex);  in drm_lease_filter_crtcs()
176 	list_for_each_entry(crtc, &dev->mode_config.crtc_list, head) {  in drm_lease_filter_crtcs()
177 		if (_drm_lease_held_master(master, crtc->base.id)) {  in drm_lease_filter_crtcs()
189 	mutex_unlock(&master->dev->mode_config.idr_mutex);  in drm_lease_filter_crtcs()
192 	drm_master_put(&master);  in drm_lease_filter_crtcs()
201  * 	ERR_PTR(-EACCES)	some other master holds the title to any object
202  * 	ERR_PTR(-ENOENT)	some object is not a valid DRM object for this device
203  * 	ERR_PTR(-EBUSY)		some other lessee holds title to this object
204  *	ERR_PTR(-EEXIST)	same object specified more than once in the provided list
205  *	ERR_PTR(-ENOMEM)	allocation failed
209 	struct drm_device *dev = lessor->dev;  in drm_lease_create()
216 	drm_dbg_lease(dev, "lessor %d\n", lessor->lessee_id);  in drm_lease_create()
218 	lessee = drm_master_create(lessor->dev);  in drm_lease_create()
221 		return ERR_PTR(-ENOMEM);  in drm_lease_create()
224 	mutex_lock(&dev->mode_config.idr_mutex);  in drm_lease_create()
228 		if (!idr_find(&dev->mode_config.object_idr, object))  in drm_lease_create()
229 			error = -ENOENT;  in drm_lease_create()
231 			error = -EBUSY;  in drm_lease_create()
240 	id = idr_alloc(&(drm_lease_owner(lessor)->lessee_idr), lessee, 1, 0, GFP_KERNEL);  in drm_lease_create()
246 	lessee->lessee_id = id;  in drm_lease_create()
247 	lessee->lessor = drm_master_get(lessor);  in drm_lease_create()
248 	list_add_tail(&lessee->lessee_list, &lessor->lessees);  in drm_lease_create()
251 	lessee->leases = *leases;  in drm_lease_create()
253 		      lessee->lessee_id, lessee, lessor->lessee_id, lessor);  in drm_lease_create()
255 	mutex_unlock(&dev->mode_config.idr_mutex);  in drm_lease_create()
259 	mutex_unlock(&dev->mode_config.idr_mutex);  in drm_lease_create()
266 void drm_lease_destroy(struct drm_master *master)  in drm_lease_destroy()  argument
268 	struct drm_device *dev = master->dev;  in drm_lease_destroy()
270 	mutex_lock(&dev->mode_config.idr_mutex);  in drm_lease_destroy()
272 	drm_dbg_lease(dev, "drm_lease_destroy %d\n", master->lessee_id);  in drm_lease_destroy()
274 	/* This master is referenced by all lessees, hence it cannot be destroyed  in drm_lease_destroy()
277 	WARN_ON(!list_empty(&master->lessees));  in drm_lease_destroy()
279 	/* Remove this master from the lessee idr in the owner */  in drm_lease_destroy()
280 	if (master->lessee_id != 0) {  in drm_lease_destroy()
281 		drm_dbg_lease(dev, "remove master %d from device list of lessees\n",  in drm_lease_destroy()
282 			      master->lessee_id);  in drm_lease_destroy()
283 		idr_remove(&(drm_lease_owner(master)->lessee_idr), master->lessee_id);  in drm_lease_destroy()
286 	/* Remove this master from any lessee list it may be on */  in drm_lease_destroy()
287 	list_del(&master->lessee_list);  in drm_lease_destroy()
289 	mutex_unlock(&dev->mode_config.idr_mutex);  in drm_lease_destroy()
291 	if (master->lessor) {  in drm_lease_destroy()
292 		/* Tell the master to check the lessee list */  in drm_lease_destroy()
294 		drm_master_put(&master->lessor);  in drm_lease_destroy()
297 	drm_dbg_lease(dev, "drm_lease_destroy done %d\n", master->lessee_id);  in drm_lease_destroy()
304 	struct drm_master *master = top;  in _drm_lease_revoke()  local
306 	lockdep_assert_held(&top->dev->mode_config.idr_mutex);  in _drm_lease_revoke()
313 		drm_dbg_lease(master->dev, "revoke leases for %p %d\n",  in _drm_lease_revoke()
314 			      master, master->lessee_id);  in _drm_lease_revoke()
317 		idr_for_each_entry(&master->leases, entry, object)  in _drm_lease_revoke()
318 			idr_remove(&master->leases, object);  in _drm_lease_revoke()
320 		/* Depth-first list walk */  in _drm_lease_revoke()
323 		if (!list_empty(&master->lessees)) {  in _drm_lease_revoke()
324 			master = list_first_entry(&master->lessees, struct drm_master, lessee_list);  in _drm_lease_revoke()
327 …while (master != top && master == list_last_entry(&master->lessor->lessees, struct drm_master, les…  in _drm_lease_revoke()
328 				master = master->lessor;  in _drm_lease_revoke()
330 			if (master == top)  in _drm_lease_revoke()
334 			master = list_next_entry(master, lessee_list);  in _drm_lease_revoke()
341 	mutex_lock(&top->dev->mode_config.idr_mutex);  in drm_lease_revoke()
343 	mutex_unlock(&top->dev->mode_config.idr_mutex);  in drm_lease_revoke()
352 	int has_crtc = -1;  in validate_lease()
353 	int has_connector = -1;  in validate_lease()
354 	int has_plane = -1;  in validate_lease()
360 		if (objects[o]->type == DRM_MODE_OBJECT_CRTC && has_crtc == -1) {  in validate_lease()
363 		if (objects[o]->type == DRM_MODE_OBJECT_CONNECTOR && has_connector == -1)  in validate_lease()
367 			if (objects[o]->type == DRM_MODE_OBJECT_PLANE && has_plane == -1)  in validate_lease()
371 	if (has_crtc == -1 || has_connector == -1)  in validate_lease()
372 		return -EINVAL;  in validate_lease()
373 	if (universal_planes && has_plane == -1)  in validate_lease()
374 		return -EINVAL;  in validate_lease()
387 	bool universal_planes = READ_ONCE(lessor_priv->universal_planes);  in fill_object_idr()
392 		return -ENOMEM;  in fill_object_idr()
394 	/* step one - get references to all the mode objects  in fill_object_idr()
401 			ret = -ENOENT;  in fill_object_idr()
405 		if (!drm_mode_object_lease_required(objects[o]->type)) {  in fill_object_idr()
407 			ret = -EINVAL;  in fill_object_idr()
418 	/* add their IDs to the lease request - taking into account  in fill_object_idr()
422 		u32 object_id = objects[o]->id;  in fill_object_idr()
431 		 * really want is a 'leased/not-leased' result, for  in fill_object_idr()
432 		 * which any non-NULL pointer will work fine.  in fill_object_idr()
440 		if (obj->type == DRM_MODE_OBJECT_CRTC && !universal_planes) {  in fill_object_idr()
443 …ret = idr_alloc(leases, &drm_lease_idr_object, crtc->primary->base.id, crtc->primary->base.id + 1,…  in fill_object_idr()
449 			if (crtc->cursor) {  in fill_object_idr()
450 …ret = idr_alloc(leases, &drm_lease_idr_object, crtc->cursor->base.id, crtc->cursor->base.id + 1, G…  in fill_object_idr()
471  * The master associated with the specified file will have a lease
486 	struct file *lessor_file = lessor_priv->filp;  in drm_mode_create_lease_ioctl()
488 	int fd = -1;  in drm_mode_create_lease_ioctl()
493 		return -EOPNOTSUPP;  in drm_mode_create_lease_ioctl()
495 	if (cl->flags && (cl->flags & ~(O_CLOEXEC | O_NONBLOCK))) {  in drm_mode_create_lease_ioctl()
497 		return -EINVAL;  in drm_mode_create_lease_ioctl()
501 	/* Do not allow sub-leases */  in drm_mode_create_lease_ioctl()
502 	if (lessor->lessor) {  in drm_mode_create_lease_ioctl()
504 		ret = -EINVAL;  in drm_mode_create_lease_ioctl()
508 	object_count = cl->object_count;  in drm_mode_create_lease_ioctl()
513 		object_ids = memdup_array_user(u64_to_user_ptr(cl->object_ids),  in drm_mode_create_lease_ioctl()
533 	fd = get_unused_fd_flags(cl->flags & (O_CLOEXEC | O_NONBLOCK));  in drm_mode_create_lease_ioctl()
558 	lessee_priv = lessee_file->private_data;  in drm_mode_create_lease_ioctl()
559 	/* Change the file to a master one */  in drm_mode_create_lease_ioctl()
560 	drm_master_put(&lessee_priv->master);  in drm_mode_create_lease_ioctl()
561 	lessee_priv->master = lessee;  in drm_mode_create_lease_ioctl()
562 	lessee_priv->is_master = 1;  in drm_mode_create_lease_ioctl()
563 	lessee_priv->authenticated = 1;  in drm_mode_create_lease_ioctl()
566 	drm_dbg_lease(dev, "Returning fd %d id %d\n", fd, lessee->lessee_id);  in drm_mode_create_lease_ioctl()
567 	cl->fd = fd;  in drm_mode_create_lease_ioctl()
568 	cl->lessee_id = lessee->lessee_id;  in drm_mode_create_lease_ioctl()
593 	__u32 __user *lessee_ids = (__u32 __user *) (uintptr_t) (arg->lessees_ptr);  in drm_mode_list_lessees_ioctl()
594 	__u32 count_lessees = arg->count_lessees;  in drm_mode_list_lessees_ioctl()
599 	if (arg->pad)  in drm_mode_list_lessees_ioctl()
600 		return -EINVAL;  in drm_mode_list_lessees_ioctl()
604 		return -EOPNOTSUPP;  in drm_mode_list_lessees_ioctl()
607 	drm_dbg_lease(dev, "List lessees for %d\n", lessor->lessee_id);  in drm_mode_list_lessees_ioctl()
609 	mutex_lock(&dev->mode_config.idr_mutex);  in drm_mode_list_lessees_ioctl()
613 		/* Only list un-revoked leases */  in drm_mode_list_lessees_ioctl()
614 		if (!idr_is_empty(&lessee->leases)) {  in drm_mode_list_lessees_ioctl()
617 					      lessee->lessee_id);  in drm_mode_list_lessees_ioctl()
618 				ret = put_user(lessee->lessee_id, lessee_ids + count);  in drm_mode_list_lessees_ioctl()
628 		arg->count_lessees = count;  in drm_mode_list_lessees_ioctl()
630 	mutex_unlock(&dev->mode_config.idr_mutex);  in drm_mode_list_lessees_ioctl()
641 	__u32 __user *object_ids = (__u32 __user *) (uintptr_t) (arg->objects_ptr);  in drm_mode_get_lease_ioctl()
642 	__u32 count_objects = arg->count_objects;  in drm_mode_get_lease_ioctl()
650 	if (arg->pad)  in drm_mode_get_lease_ioctl()
651 		return -EINVAL;  in drm_mode_get_lease_ioctl()
655 		return -EOPNOTSUPP;  in drm_mode_get_lease_ioctl()
658 	drm_dbg_lease(dev, "get lease for %d\n", lessee->lessee_id);  in drm_mode_get_lease_ioctl()
660 	mutex_lock(&dev->mode_config.idr_mutex);  in drm_mode_get_lease_ioctl()
662 	if (lessee->lessor == NULL)  in drm_mode_get_lease_ioctl()
664 		object_idr = &lessee->dev->mode_config.object_idr;  in drm_mode_get_lease_ioctl()
667 		object_idr = &lessee->leases;  in drm_mode_get_lease_ioctl()
682 		arg->count_objects = count;  in drm_mode_get_lease_ioctl()
684 	mutex_unlock(&dev->mode_config.idr_mutex);  in drm_mode_get_lease_ioctl()
703 	drm_dbg_lease(dev, "revoke lease for %d\n", arg->lessee_id);  in drm_mode_revoke_lease_ioctl()
707 		return -EOPNOTSUPP;  in drm_mode_revoke_lease_ioctl()
710 	mutex_lock(&dev->mode_config.idr_mutex);  in drm_mode_revoke_lease_ioctl()
712 	lessee = _drm_find_lessee(lessor, arg->lessee_id);  in drm_mode_revoke_lease_ioctl()
716 		ret = -ENOENT;  in drm_mode_revoke_lease_ioctl()
721 	if (lessee->lessor != lessor) {  in drm_mode_revoke_lease_ioctl()
722 		ret = -EACCES;  in drm_mode_revoke_lease_ioctl()
729 	mutex_unlock(&dev->mode_config.idr_mutex);  in drm_mode_revoke_lease_ioctl()