2 * Copyright © 2017 Keith Packard <keithp@keithp.com>
4 * This program is free software; you can redistribute it and/or modify
5 * it under the terms of the GNU General Public License as published by
6 * the Free Software Foundation, either version 2 of the License, or
7 * (at your option) any later version.
9 * This program is distributed in the hope that it will be useful, but
10 * WITHOUT ANY WARRANTY; without even the implied warranty of
11 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
12 * General Public License for more details.
16 #include "drm_internal.h"
17 #include "drm_legacy.h"
18 #include "drm_crtc_internal.h"
19 #include <drm/drm_lease.h>
20 #include <drm/drm_auth.h>
21 #include <drm/drm_crtc_helper.h>
23 #define drm_for_each_lessee(lessee, lessor) \
24 list_for_each_entry((lessee), &(lessor)->lessees, lessee_list)
26 static uint64_t drm_lease_idr_object;
29 * drm_lease_owner - return ancestor owner drm_master
30 * @master: drm_master somewhere within tree of lessees and lessors
34 * drm_master at the top of the tree (i.e, with lessor NULL
36 struct drm_master *drm_lease_owner(struct drm_master *master)
38 while (master->lessor != NULL)
39 master = master->lessor;
44 * _drm_find_lessee - find lessee by id (idr_mutex held)
45 * @master: drm_master of lessor
50 * drm_master of the lessee if valid, NULL otherwise
53 static struct drm_master*
54 _drm_find_lessee(struct drm_master *master, int lessee_id)
56 lockdep_assert_held(&master->dev->mode_config.idr_mutex);
57 return idr_find(&drm_lease_owner(master)->lessee_idr, lessee_id);
61 * _drm_lease_held_master - check to see if an object is leased (or owned) by master (idr_mutex held)
62 * @master: the master to check the lease status of
63 * @id: the id to check
65 * Checks if the specified master holds a lease on the object. Return
68 * true 'master' holds a lease on (or owns) the object
69 * false 'master' does not hold a lease.
71 static int _drm_lease_held_master(struct drm_master *master, int id)
73 lockdep_assert_held(&master->dev->mode_config.idr_mutex);
75 return idr_find(&master->leases, id) != NULL;
80 * _drm_has_leased - check to see if an object has been leased (idr_mutex held)
81 * @master: the master to check the lease status of
82 * @id: the id to check
84 * Checks if any lessee of 'master' holds a lease on 'id'. Return
87 * true Some lessee holds a lease on the object.
88 * false No lessee has a lease on the object.
90 static bool _drm_has_leased(struct drm_master *master, int id)
92 struct drm_master *lessee;
94 lockdep_assert_held(&master->dev->mode_config.idr_mutex);
95 drm_for_each_lessee(lessee, master)
96 if (_drm_lease_held_master(lessee, id))
102 * _drm_lease_held - check drm_mode_object lease status (idr_mutex held)
103 * @file_priv: the master drm_file
106 * Checks if the specified master holds a lease on the object. Return
109 * true 'master' holds a lease on (or owns) the object
110 * false 'master' does not hold a lease.
112 bool _drm_lease_held(struct drm_file *file_priv, int id)
114 if (file_priv == NULL || file_priv->master == NULL)
117 return _drm_lease_held_master(file_priv->master, id);
121 * drm_lease_held - check drm_mode_object lease status (idr_mutex not held)
122 * @file_priv: the master drm_file
125 * Checks if the specified master holds a lease on the object. Return
128 * true 'master' holds a lease on (or owns) the object
129 * false 'master' does not hold a lease.
131 bool drm_lease_held(struct drm_file *file_priv, int id)
133 struct drm_master *master;
136 if (file_priv == NULL || file_priv->master == NULL)
139 master = file_priv->master;
140 mutex_lock(&master->dev->mode_config.idr_mutex);
141 ret = _drm_lease_held_master(master, id);
142 mutex_unlock(&master->dev->mode_config.idr_mutex);
147 * drm_lease_filter_crtcs - restricted crtc set to leased values (idr_mutex not held)
148 * @file_priv: requestor file
149 * @crtcs_in: bitmask of crtcs to check
151 * Reconstructs a crtc mask based on the crtcs which are visible
152 * through the specified file.
154 uint32_t drm_lease_filter_crtcs(struct drm_file *file_priv, uint32_t crtcs_in)
156 struct drm_master *master;
157 struct drm_device *dev;
158 struct drm_crtc *crtc;
159 int count_in, count_out;
160 uint32_t crtcs_out = 0;
162 if (file_priv == NULL || file_priv->master == NULL)
165 master = file_priv->master;
168 count_in = count_out = 0;
169 mutex_lock(&master->dev->mode_config.idr_mutex);
170 list_for_each_entry(crtc, &dev->mode_config.crtc_list, head) {
171 if (_drm_lease_held_master(master, crtc->base.id)) {
172 uint32_t mask_in = 1ul << count_in;
173 if ((crtcs_in & mask_in) != 0) {
174 uint32_t mask_out = 1ul << count_out;
175 crtcs_out |= mask_out;
181 mutex_unlock(&master->dev->mode_config.idr_mutex);
186 * drm_lease_create - create a new drm_master with leased objects (idr_mutex not held)
187 * @lessor: lease holder (or owner) of objects
188 * @leases: objects to lease to the new drm_master
190 * Uses drm_master_create to allocate a new drm_master, then checks to
191 * make sure all of the desired objects can be leased, atomically
192 * leasing them to the new drmmaster.
194 * ERR_PTR(-EACCES) some other master holds the title to any object
195 * ERR_PTR(-ENOENT) some object is not a valid DRM object for this device
196 * ERR_PTR(-EBUSY) some other lessee holds title to this object
197 * ERR_PTR(-EEXIST) same object specified more than once in the provided list
198 * ERR_PTR(-ENOMEM) allocation failed
200 static struct drm_master *drm_lease_create(struct drm_master *lessor, struct idr *leases)
202 struct drm_device *dev = lessor->dev;
204 struct drm_master *lessee;
209 DRM_DEBUG_LEASE("lessor %d\n", lessor->lessee_id);
211 lessee = drm_master_create(lessor->dev);
213 DRM_DEBUG_LEASE("drm_master_create failed\n");
214 return ERR_PTR(-ENOMEM);
217 mutex_lock(&dev->mode_config.idr_mutex);
219 idr_for_each_entry(leases, entry, object) {
221 if (!idr_find(&dev->mode_config.object_idr, object))
223 else if (!_drm_lease_held_master(lessor, object))
225 else if (_drm_has_leased(lessor, object))
229 DRM_DEBUG_LEASE("object %d failed %d\n", object, error);
234 /* Insert the new lessee into the tree */
235 id = idr_alloc(&(drm_lease_owner(lessor)->lessee_idr), lessee, 1, 0, GFP_KERNEL);
241 lessee->lessee_id = id;
242 lessee->lessor = drm_master_get(lessor);
243 list_add_tail(&lessee->lessee_list, &lessor->lessees);
245 /* Move the leases over */
246 lessee->leases = *leases;
247 DRM_DEBUG_LEASE("new lessee %d %p, lessor %d %p\n", lessee->lessee_id, lessee, lessor->lessee_id, lessor);
249 mutex_unlock(&dev->mode_config.idr_mutex);
253 mutex_unlock(&dev->mode_config.idr_mutex);
255 drm_master_put(&lessee);
257 return ERR_PTR(error);
261 * drm_lease_destroy - a master is going away (idr_mutex not held)
262 * @master: the drm_master being destroyed
264 * All lessees will have been destroyed as they
265 * hold a reference on their lessor. Notify any
266 * lessor for this master so that it can check
267 * the list of lessees.
269 void drm_lease_destroy(struct drm_master *master)
271 struct drm_device *dev = master->dev;
273 mutex_lock(&dev->mode_config.idr_mutex);
275 DRM_DEBUG_LEASE("drm_lease_destroy %d\n", master->lessee_id);
277 /* This master is referenced by all lessees, hence it cannot be destroyed
278 * until all of them have been
280 WARN_ON(!list_empty(&master->lessees));
282 /* Remove this master from the lessee idr in the owner */
283 if (master->lessee_id != 0) {
284 DRM_DEBUG_LEASE("remove master %d from device list of lessees\n", master->lessee_id);
285 idr_remove(&(drm_lease_owner(master)->lessee_idr), master->lessee_id);
288 /* Remove this master from any lessee list it may be on */
289 list_del(&master->lessee_list);
291 mutex_unlock(&dev->mode_config.idr_mutex);
293 if (master->lessor) {
294 /* Tell the master to check the lessee list */
295 drm_sysfs_lease_event(dev);
296 drm_master_put(&master->lessor);
299 DRM_DEBUG_LEASE("drm_lease_destroy done %d\n", master->lessee_id);
303 * _drm_lease_revoke - revoke access to all leased objects (idr_mutex held)
304 * @top: the master losing its lease
306 static void _drm_lease_revoke(struct drm_master *top)
310 struct drm_master *master = top;
312 lockdep_assert_held(&top->dev->mode_config.idr_mutex);
315 * Walk the tree starting at 'top' emptying all leases. Because
316 * the tree is fully connected, we can do this without recursing
319 DRM_DEBUG_LEASE("revoke leases for %p %d\n", master, master->lessee_id);
321 /* Evacuate the lease */
322 idr_for_each_entry(&master->leases, entry, object)
323 idr_remove(&master->leases, object);
325 /* Depth-first list walk */
328 if (!list_empty(&master->lessees)) {
329 master = list_first_entry(&master->lessees, struct drm_master, lessee_list);
332 while (master != top && master == list_last_entry(&master->lessor->lessees, struct drm_master, lessee_list))
333 master = master->lessor;
339 master = list_next_entry(master, lessee_list);
345 * drm_lease_revoke - revoke access to all leased objects (idr_mutex not held)
346 * @top: the master losing its lease
348 void drm_lease_revoke(struct drm_master *top)
350 mutex_lock(&top->dev->mode_config.idr_mutex);
351 _drm_lease_revoke(top);
352 mutex_unlock(&top->dev->mode_config.idr_mutex);
355 static int validate_lease(struct drm_device *dev,
357 struct drm_mode_object **objects,
358 bool universal_planes)
362 int has_connector = -1;
365 /* we want to confirm that there is at least one crtc, plane
368 for (o = 0; o < object_count; o++) {
369 if (objects[o]->type == DRM_MODE_OBJECT_CRTC && has_crtc == -1) {
372 if (objects[o]->type == DRM_MODE_OBJECT_CONNECTOR && has_connector == -1)
375 if (universal_planes) {
376 if (objects[o]->type == DRM_MODE_OBJECT_PLANE && has_plane == -1)
380 if (has_crtc == -1 || has_connector == -1)
382 if (universal_planes && has_plane == -1)
387 static int fill_object_idr(struct drm_device *dev,
388 struct drm_file *lessor_priv,
393 struct drm_mode_object **objects;
396 bool universal_planes = READ_ONCE(lessor_priv->universal_planes);
398 objects = kcalloc(object_count, sizeof(struct drm_mode_object *),
403 /* step one - get references to all the mode objects
404 and check for validity. */
405 for (o = 0; o < object_count; o++) {
406 objects[o] = drm_mode_object_find(dev, lessor_priv,
408 DRM_MODE_OBJECT_ANY);
411 goto out_free_objects;
414 if (!drm_mode_object_lease_required(objects[o]->type)) {
415 DRM_DEBUG_KMS("invalid object for lease\n");
417 goto out_free_objects;
421 ret = validate_lease(dev, object_count, objects, universal_planes);
423 DRM_DEBUG_LEASE("lease validation failed\n");
424 goto out_free_objects;
427 /* add their IDs to the lease request - taking into account
429 for (o = 0; o < object_count; o++) {
430 struct drm_mode_object *obj = objects[o];
431 u32 object_id = objects[o]->id;
432 DRM_DEBUG_LEASE("Adding object %d to lease\n", object_id);
435 * We're using an IDR to hold the set of leased
436 * objects, but we don't need to point at the object's
437 * data structure from the lease as the main object_idr
438 * will be used to actually find that. Instead, all we
439 * really want is a 'leased/not-leased' result, for
440 * which any non-NULL pointer will work fine.
442 ret = idr_alloc(leases, &drm_lease_idr_object , object_id, object_id + 1, GFP_KERNEL);
444 DRM_DEBUG_LEASE("Object %d cannot be inserted into leases (%d)\n",
446 goto out_free_objects;
448 if (obj->type == DRM_MODE_OBJECT_CRTC && !universal_planes) {
449 struct drm_crtc *crtc = obj_to_crtc(obj);
450 ret = idr_alloc(leases, &drm_lease_idr_object, crtc->primary->base.id, crtc->primary->base.id + 1, GFP_KERNEL);
452 DRM_DEBUG_LEASE("Object primary plane %d cannot be inserted into leases (%d)\n",
454 goto out_free_objects;
457 ret = idr_alloc(leases, &drm_lease_idr_object, crtc->cursor->base.id, crtc->cursor->base.id + 1, GFP_KERNEL);
459 DRM_DEBUG_LEASE("Object cursor plane %d cannot be inserted into leases (%d)\n",
461 goto out_free_objects;
469 for (o = 0; o < object_count; o++) {
471 drm_mode_object_put(objects[o]);
478 * drm_mode_create_lease_ioctl - create a new lease
479 * @dev: the drm device
480 * @data: pointer to struct drm_mode_create_lease
481 * @lessor_priv: the file being manipulated
483 * The master associated with the specified file will have a lease
484 * created containing the objects specified in the ioctl structure.
485 * A file descriptor will be allocated for that and returned to the
488 int drm_mode_create_lease_ioctl(struct drm_device *dev,
489 void *data, struct drm_file *lessor_priv)
491 struct drm_mode_create_lease *cl = data;
495 struct drm_master *lessor = lessor_priv->master;
496 struct drm_master *lessee = NULL;
497 struct file *lessee_file = NULL;
498 struct file *lessor_file = lessor_priv->filp;
499 struct drm_file *lessee_priv;
501 uint32_t *object_ids;
503 /* Can't lease without MODESET */
504 if (!drm_core_check_feature(dev, DRIVER_MODESET))
507 /* Do not allow sub-leases */
508 if (lessor->lessor) {
509 DRM_DEBUG_LEASE("recursive leasing not allowed\n");
513 /* need some objects */
514 if (cl->object_count == 0) {
515 DRM_DEBUG_LEASE("no objects in lease\n");
519 if (cl->flags && (cl->flags & ~(O_CLOEXEC | O_NONBLOCK))) {
520 DRM_DEBUG_LEASE("invalid flags\n");
524 object_count = cl->object_count;
526 object_ids = memdup_user(u64_to_user_ptr(cl->object_ids),
527 array_size(object_count, sizeof(__u32)));
528 if (IS_ERR(object_ids))
529 return PTR_ERR(object_ids);
533 /* fill and validate the object idr */
534 ret = fill_object_idr(dev, lessor_priv, &leases,
535 object_count, object_ids);
538 DRM_DEBUG_LEASE("lease object lookup failed: %i\n", ret);
539 idr_destroy(&leases);
543 /* Allocate a file descriptor for the lease */
544 fd = get_unused_fd_flags(cl->flags & (O_CLOEXEC | O_NONBLOCK));
546 idr_destroy(&leases);
550 DRM_DEBUG_LEASE("Creating lease\n");
551 lessee = drm_lease_create(lessor, &leases);
553 if (IS_ERR(lessee)) {
554 ret = PTR_ERR(lessee);
558 /* Clone the lessor file to create a new file for us */
559 DRM_DEBUG_LEASE("Allocating lease file\n");
560 lessee_file = file_clone_open(lessor_file);
561 if (IS_ERR(lessee_file)) {
562 ret = PTR_ERR(lessee_file);
566 lessee_priv = lessee_file->private_data;
567 /* Change the file to a master one */
568 drm_master_put(&lessee_priv->master);
569 lessee_priv->master = lessee;
570 lessee_priv->is_master = 1;
571 lessee_priv->authenticated = 1;
573 /* Pass fd back to userspace */
574 DRM_DEBUG_LEASE("Returning fd %d id %d\n", fd, lessee->lessee_id);
576 cl->lessee_id = lessee->lessee_id;
579 fd_install(fd, lessee_file);
581 DRM_DEBUG_LEASE("drm_mode_create_lease_ioctl succeeded\n");
585 drm_master_put(&lessee);
589 idr_destroy(&leases);
591 DRM_DEBUG_LEASE("drm_mode_create_lease_ioctl failed: %d\n", ret);
596 * drm_mode_list_lessees_ioctl - list lessee ids
597 * @dev: the drm device
598 * @data: pointer to struct drm_mode_list_lessees
599 * @lessor_priv: the file being manipulated
601 * Starting from the master associated with the specified file,
602 * the master with the provided lessee_id is found, and then
603 * an array of lessee ids associated with leases from that master
607 int drm_mode_list_lessees_ioctl(struct drm_device *dev,
608 void *data, struct drm_file *lessor_priv)
610 struct drm_mode_list_lessees *arg = data;
611 __u32 __user *lessee_ids = (__u32 __user *) (uintptr_t) (arg->lessees_ptr);
612 __u32 count_lessees = arg->count_lessees;
613 struct drm_master *lessor = lessor_priv->master, *lessee;
620 /* Can't lease without MODESET */
621 if (!drm_core_check_feature(dev, DRIVER_MODESET))
624 DRM_DEBUG_LEASE("List lessees for %d\n", lessor->lessee_id);
626 mutex_lock(&dev->mode_config.idr_mutex);
629 drm_for_each_lessee(lessee, lessor) {
630 /* Only list un-revoked leases */
631 if (!idr_is_empty(&lessee->leases)) {
632 if (count_lessees > count) {
633 DRM_DEBUG_LEASE("Add lessee %d\n", lessee->lessee_id);
634 ret = put_user(lessee->lessee_id, lessee_ids + count);
642 DRM_DEBUG_LEASE("Lessor leases to %d\n", count);
644 arg->count_lessees = count;
646 mutex_unlock(&dev->mode_config.idr_mutex);
652 * drm_mode_get_lease_ioctl - list leased objects
653 * @dev: the drm device
654 * @data: pointer to struct drm_mode_get_lease
655 * @lessee_priv: the file being manipulated
657 * Return the list of leased objects for the specified lessee
660 int drm_mode_get_lease_ioctl(struct drm_device *dev,
661 void *data, struct drm_file *lessee_priv)
663 struct drm_mode_get_lease *arg = data;
664 __u32 __user *object_ids = (__u32 __user *) (uintptr_t) (arg->objects_ptr);
665 __u32 count_objects = arg->count_objects;
666 struct drm_master *lessee = lessee_priv->master;
667 struct idr *object_idr;
676 /* Can't lease without MODESET */
677 if (!drm_core_check_feature(dev, DRIVER_MODESET))
680 DRM_DEBUG_LEASE("get lease for %d\n", lessee->lessee_id);
682 mutex_lock(&dev->mode_config.idr_mutex);
684 if (lessee->lessor == NULL)
685 /* owner can use all objects */
686 object_idr = &lessee->dev->mode_config.object_idr;
688 /* lessee can only use allowed object */
689 object_idr = &lessee->leases;
692 idr_for_each_entry(object_idr, entry, object) {
693 if (count_objects > count) {
694 DRM_DEBUG_LEASE("adding object %d\n", object);
695 ret = put_user(object, object_ids + count);
702 DRM_DEBUG("lease holds %d objects\n", count);
704 arg->count_objects = count;
706 mutex_unlock(&dev->mode_config.idr_mutex);
712 * drm_mode_revoke_lease_ioctl - revoke lease
713 * @dev: the drm device
714 * @data: pointer to struct drm_mode_revoke_lease
715 * @lessor_priv: the file being manipulated
717 * This removes all of the objects from the lease without
718 * actually getting rid of the lease itself; that way all
719 * references to it still work correctly
721 int drm_mode_revoke_lease_ioctl(struct drm_device *dev,
722 void *data, struct drm_file *lessor_priv)
724 struct drm_mode_revoke_lease *arg = data;
725 struct drm_master *lessor = lessor_priv->master;
726 struct drm_master *lessee;
729 DRM_DEBUG_LEASE("revoke lease for %d\n", arg->lessee_id);
731 /* Can't lease without MODESET */
732 if (!drm_core_check_feature(dev, DRIVER_MODESET))
735 mutex_lock(&dev->mode_config.idr_mutex);
737 lessee = _drm_find_lessee(lessor, arg->lessee_id);
745 /* Lease is not held by lessor */
746 if (lessee->lessor != lessor) {
751 _drm_lease_revoke(lessee);
754 mutex_unlock(&dev->mode_config.idr_mutex);