drivers/gpu/drm/drm_lease.c

   1 /*
   2  * Copyright © 2017 Keith Packard <keithp@keithp.com>
   3  *
   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.
   8  *
   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.
  13  */
  14
  15 #include <drm/drmP.h>
  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>
  22
  23 #define drm_for_each_lessee(lessee, lessor) \
  24         list_for_each_entry((lessee), &(lessor)->lessees, lessee_list)
  25
  26 static uint64_t drm_lease_idr_object;
  27
  28 /**
  29  * drm_lease_owner - return ancestor owner drm_master
  30  * @master: drm_master somewhere within tree of lessees and lessors
  31  *
  32  * RETURN:
  33  *
  34  * drm_master at the top of the tree (i.e, with lessor NULL
  35  */
  36 struct drm_master *drm_lease_owner(struct drm_master *master)
  37 {
  38         while (master->lessor != NULL)
  39                 master = master->lessor;
  40         return master;
  41 }
  42 EXPORT_SYMBOL(drm_lease_owner);
  43
  44 /**
  45  * _drm_find_lessee - find lessee by id (idr_mutex held)
  46  * @master: drm_master of lessor
  47  * @lessee_id: id
  48  *
  49  * RETURN:
  50  *
  51  * drm_master of the lessee if valid, NULL otherwise
  52  */
  53
  54 static struct drm_master*
  55 _drm_find_lessee(struct drm_master *master, int lessee_id)
  56 {
  57         lockdep_assert_held(&master->dev->mode_config.idr_mutex);
  58         return idr_find(&drm_lease_owner(master)->lessee_idr, lessee_id);
  59 }
  60
  61 /**
  62  * _drm_lease_held_master - check to see if an object is leased (or owned) by master (idr_mutex held)
  63  * @master: the master to check the lease status of
  64  * @id: the id to check
  65  *
  66  * Checks if the specified master holds a lease on the object. Return
  67  * value:
  68  *
  69  *      true            'master' holds a lease on (or owns) the object
  70  *      false           'master' does not hold a lease.
  71  */
  72 static int _drm_lease_held_master(struct drm_master *master, int id)
  73 {
  74         lockdep_assert_held(&master->dev->mode_config.idr_mutex);
  75         if (master->lessor)
  76                 return idr_find(&master->leases, id) != NULL;
  77         return true;
  78 }
  79
  80 /**
  81  * _drm_has_leased - check to see if an object has been leased (idr_mutex held)
  82  * @master: the master to check the lease status of
  83  * @id: the id to check
  84  *
  85  * Checks if any lessee of 'master' holds a lease on 'id'. Return
  86  * value:
  87  *
  88  *      true            Some lessee holds a lease on the object.
  89  *      false           No lessee has a lease on the object.
  90  */
  91 static bool _drm_has_leased(struct drm_master *master, int id)
  92 {
  93         struct drm_master *lessee;
  94
  95         lockdep_assert_held(&master->dev->mode_config.idr_mutex);
  96         drm_for_each_lessee(lessee, master)
  97                 if (_drm_lease_held_master(lessee, id))
  98                         return true;
  99         return false;
 100 }
 101
 102 /**
 103  * _drm_lease_held - check drm_mode_object lease status (idr_mutex held)
 104  * @file_priv: the master drm_file
 105  * @id: the object id
 106  *
 107  * Checks if the specified master holds a lease on the object. Return
 108  * value:
 109  *
 110  *      true            'master' holds a lease on (or owns) the object
 111  *      false           'master' does not hold a lease.
 112  */
 113 bool _drm_lease_held(struct drm_file *file_priv, int id)
 114 {
 115         if (file_priv == NULL || file_priv->master == NULL)
 116                 return true;
 117
 118         return _drm_lease_held_master(file_priv->master, id);
 119 }
 120 EXPORT_SYMBOL(_drm_lease_held);
 121
 122 /**
 123  * drm_lease_held - check drm_mode_object lease status (idr_mutex not held)
 124  * @file_priv: the master drm_file
 125  * @id: the object id
 126  *
 127  * Checks if the specified master holds a lease on the object. Return
 128  * value:
 129  *
 130  *      true            'master' holds a lease on (or owns) the object
 131  *      false           'master' does not hold a lease.
 132  */
 133 bool drm_lease_held(struct drm_file *file_priv, int id)
 134 {
 135         struct drm_master *master;
 136         bool ret;
 137
 138         if (file_priv == NULL || file_priv->master == NULL)
 139                 return true;
 140
 141         master = file_priv->master;
 142         mutex_lock(&master->dev->mode_config.idr_mutex);
 143         ret = _drm_lease_held_master(master, id);
 144         mutex_unlock(&master->dev->mode_config.idr_mutex);
 145         return ret;
 146 }
 147 EXPORT_SYMBOL(drm_lease_held);
 148
 149 /**
 150  * drm_lease_filter_crtcs - restricted crtc set to leased values (idr_mutex not held)
 151  * @file_priv: requestor file
 152  * @crtcs_in: bitmask of crtcs to check
 153  *
 154  * Reconstructs a crtc mask based on the crtcs which are visible
 155  * through the specified file.
 156  */
 157 uint32_t drm_lease_filter_crtcs(struct drm_file *file_priv, uint32_t crtcs_in)
 158 {
 159         struct drm_master *master;
 160         struct drm_device *dev;
 161         struct drm_crtc *crtc;
 162         int count_in, count_out;
 163         uint32_t crtcs_out = 0;
 164
 165         if (file_priv == NULL || file_priv->master == NULL)
 166                 return crtcs_in;
 167
 168         master = file_priv->master;
 169         dev = master->dev;
 170
 171         count_in = count_out = 0;
 172         mutex_lock(&master->dev->mode_config.idr_mutex);
 173         list_for_each_entry(crtc, &dev->mode_config.crtc_list, head) {
 174                 if (_drm_lease_held_master(master, crtc->base.id)) {
 175                         uint32_t mask_in = 1ul << count_in;
 176                         if ((crtcs_in & mask_in) != 0) {
 177                                 uint32_t mask_out = 1ul << count_out;
 178                                 crtcs_out |= mask_out;
 179                         }
 180                         count_out++;
 181                 }
 182                 count_in++;
 183         }
 184         mutex_unlock(&master->dev->mode_config.idr_mutex);
 185         return crtcs_out;
 186 }
 187 EXPORT_SYMBOL(drm_lease_filter_crtcs);
 188
 189 /*
 190  * drm_lease_create - create a new drm_master with leased objects (idr_mutex not held)
 191  * @lessor: lease holder (or owner) of objects
 192  * @leases: objects to lease to the new drm_master
 193  *
 194  * Uses drm_master_create to allocate a new drm_master, then checks to
 195  * make sure all of the desired objects can be leased, atomically
 196  * leasing them to the new drmmaster.
 197  *
 198  *      ERR_PTR(-EACCESS)       some other master holds the title to any object
 199  *      ERR_PTR(-ENOENT)        some object is not a valid DRM object for this device
 200  *      ERR_PTR(-EBUSY)         some other lessee holds title to this object
 201  *      ERR_PTR(-EEXIST)        same object specified more than once in the provided list
 202  *      ERR_PTR(-ENOMEM)        allocation failed
 203  */
 204 static struct drm_master *drm_lease_create(struct drm_master *lessor, struct idr *leases)
 205 {
 206         struct drm_device *dev = lessor->dev;
 207         int error;
 208         struct drm_master *lessee;
 209         int object;
 210         int id;
 211         void *entry;
 212
 213         DRM_DEBUG_LEASE("lessor %d\n", lessor->lessee_id);
 214
 215         lessee = drm_master_create(lessor->dev);
 216         if (!lessee) {
 217                 DRM_DEBUG_LEASE("drm_master_create failed\n");
 218                 return ERR_PTR(-ENOMEM);
 219         }
 220
 221         mutex_lock(&dev->mode_config.idr_mutex);
 222
 223         idr_for_each_entry(leases, entry, object) {
 224                 error = 0;
 225                 if (!idr_find(&dev->mode_config.crtc_idr, object))
 226                         error = -ENOENT;
 227                 else if (!_drm_lease_held_master(lessor, object))
 228                         error = -EACCES;
 229                 else if (_drm_has_leased(lessor, object))
 230                         error = -EBUSY;
 231
 232                 if (error != 0) {
 233                         DRM_DEBUG_LEASE("object %d failed %d\n", object, error);
 234                         goto out_lessee;
 235                 }
 236         }
 237
 238         /* Insert the new lessee into the tree */
 239         id = idr_alloc(&(drm_lease_owner(lessor)->lessee_idr), lessee, 1, 0, GFP_KERNEL);
 240         if (id < 0) {
 241                 error = id;
 242                 goto out_lessee;
 243         }
 244
 245         lessee->lessee_id = id;
 246         lessee->lessor = drm_master_get(lessor);
 247         list_add_tail(&lessee->lessee_list, &lessor->lessees);
 248
 249         /* Move the leases over */
 250         lessee->leases = *leases;
 251         DRM_DEBUG_LEASE("new lessee %d %p, lessor %d %p\n", lessee->lessee_id, lessee, lessor->lessee_id, lessor);
 252
 253         mutex_unlock(&dev->mode_config.idr_mutex);
 254         return lessee;
 255
 256 out_lessee:
 257         mutex_unlock(&dev->mode_config.idr_mutex);
 258
 259         drm_master_put(&lessee);
 260
 261         return ERR_PTR(error);
 262 }
 263
 264 /**
 265  * drm_lease_destroy - a master is going away (idr_mutex not held)
 266  * @master: the drm_master being destroyed
 267  *
 268  * All lessees will have been destroyed as they
 269  * hold a reference on their lessor. Notify any
 270  * lessor for this master so that it can check
 271  * the list of lessees.
 272  */
 273 void drm_lease_destroy(struct drm_master *master)
 274 {
 275         struct drm_device *dev = master->dev;
 276
 277         mutex_lock(&dev->mode_config.idr_mutex);
 278
 279         DRM_DEBUG_LEASE("drm_lease_destroy %d\n", master->lessee_id);
 280
 281         /* This master is referenced by all lessees, hence it cannot be destroyed
 282          * until all of them have been
 283          */
 284         WARN_ON(!list_empty(&master->lessees));
 285
 286         /* Remove this master from the lessee idr in the owner */
 287         if (master->lessee_id != 0) {
 288                 DRM_DEBUG_LEASE("remove master %d from device list of lessees\n", master->lessee_id);
 289                 idr_remove(&(drm_lease_owner(master)->lessee_idr), master->lessee_id);
 290         }
 291
 292         /* Remove this master from any lessee list it may be on */
 293         list_del(&master->lessee_list);
 294
 295         mutex_unlock(&dev->mode_config.idr_mutex);
 296
 297         if (master->lessor) {
 298                 /* Tell the master to check the lessee list */
 299                 drm_sysfs_lease_event(dev);
 300                 drm_master_put(&master->lessor);
 301         }
 302
 303         DRM_DEBUG_LEASE("drm_lease_destroy done %d\n", master->lessee_id);
 304 }
 305
 306 /**
 307  * _drm_lease_revoke - revoke access to all leased objects (idr_mutex held)
 308  * @top: the master losing its lease
 309  */
 310 static void _drm_lease_revoke(struct drm_master *top)
 311 {
 312         int object;
 313         void *entry;
 314         struct drm_master *master = top;
 315
 316         lockdep_assert_held(&top->dev->mode_config.idr_mutex);
 317
 318         /*
 319          * Walk the tree starting at 'top' emptying all leases. Because
 320          * the tree is fully connected, we can do this without recursing
 321          */
 322         for (;;) {
 323                 DRM_DEBUG_LEASE("revoke leases for %p %d\n", master, master->lessee_id);
 324
 325                 /* Evacuate the lease */
 326                 idr_for_each_entry(&master->leases, entry, object)
 327                         idr_remove(&master->leases, object);
 328
 329                 /* Depth-first list walk */
 330
 331                 /* Down */
 332                 if (!list_empty(&master->lessees)) {
 333                         master = list_first_entry(&master->lessees, struct drm_master, lessee_list);
 334                 } else {
 335                         /* Up */
 336                         while (master != top && master == list_last_entry(&master->lessor->lessees, struct drm_master, lessee_list))
 337                                 master = master->lessor;
 338
 339                         if (master == top)
 340                                 break;
 341
 342                         /* Over */
 343                         master = list_next_entry(master, lessee_list);
 344                 }
 345         }
 346 }
 347
 348 /**
 349  * drm_lease_revoke - revoke access to all leased objects (idr_mutex not held)
 350  * @top: the master losing its lease
 351  */
 352 void drm_lease_revoke(struct drm_master *top)
 353 {
 354         mutex_lock(&top->dev->mode_config.idr_mutex);
 355         _drm_lease_revoke(top);
 356         mutex_unlock(&top->dev->mode_config.idr_mutex);
 357 }
 358
 359 static int validate_lease(struct drm_device *dev,
 360                           struct drm_file *lessor_priv,
 361                           int object_count,
 362                           struct drm_mode_object **objects)
 363 {
 364         int o;
 365         int has_crtc = -1;
 366         int has_connector = -1;
 367         int has_plane = -1;
 368
 369         /* we want to confirm that there is at least one crtc, plane
 370            connector object. */
 371
 372         for (o = 0; o < object_count; o++) {
 373                 if (objects[o]->type == DRM_MODE_OBJECT_CRTC && has_crtc == -1) {
 374                         has_crtc = o;
 375                 }
 376                 if (objects[o]->type == DRM_MODE_OBJECT_CONNECTOR && has_connector == -1)
 377                         has_connector = o;
 378
 379                 if (lessor_priv->universal_planes) {
 380                         if (objects[o]->type == DRM_MODE_OBJECT_PLANE && has_plane == -1)
 381                                 has_plane = o;
 382                 }
 383         }
 384         if (has_crtc == -1 || has_connector == -1)
 385                 return -EINVAL;
 386         if (lessor_priv->universal_planes && has_plane == -1)
 387                 return -EINVAL;
 388         return 0;
 389 }
 390
 391 static int fill_object_idr(struct drm_device *dev,
 392                            struct drm_file *lessor_priv,
 393                            struct idr *leases,
 394                            int object_count,
 395                            u32 *object_ids)
 396 {
 397         struct drm_mode_object **objects;
 398         u32 o;
 399         int ret;
 400         objects = kcalloc(object_count, sizeof(struct drm_mode_object *),
 401                           GFP_KERNEL);
 402         if (!objects)
 403                 return -ENOMEM;
 404
 405         /* step one - get references to all the mode objects
 406            and check for validity. */
 407         for (o = 0; o < object_count; o++) {
 408                 if ((int) object_ids[o] < 0) {
 409                         ret = -EINVAL;
 410                         goto out_free_objects;
 411                 }
 412
 413                 objects[o] = drm_mode_object_find(dev, lessor_priv,
 414                                                   object_ids[o],
 415                                                   DRM_MODE_OBJECT_ANY);
 416                 if (!objects[o]) {
 417                         ret = -ENOENT;
 418                         goto out_free_objects;
 419                 }
 420
 421                 if (!drm_mode_object_lease_required(objects[o]->type)) {
 422                         ret = -EINVAL;
 423                         goto out_free_objects;
 424                 }
 425         }
 426
 427         ret = validate_lease(dev, lessor_priv, object_count, objects);
 428         if (ret)
 429                 goto out_free_objects;
 430
 431         /* add their IDs to the lease request - taking into account
 432            universal planes */
 433         for (o = 0; o < object_count; o++) {
 434                 struct drm_mode_object *obj = objects[o];
 435                 u32 object_id = objects[o]->id;
 436                 DRM_DEBUG_LEASE("Adding object %d to lease\n", object_id);
 437
 438                 /*
 439                  * We're using an IDR to hold the set of leased
 440                  * objects, but we don't need to point at the object's
 441                  * data structure from the lease as the main crtc_idr
 442                  * will be used to actually find that. Instead, all we
 443                  * really want is a 'leased/not-leased' result, for
 444                  * which any non-NULL pointer will work fine.
 445                  */
 446                 ret = idr_alloc(leases, &drm_lease_idr_object , object_id, object_id + 1, GFP_KERNEL);
 447                 if (ret < 0) {
 448                         DRM_DEBUG_LEASE("Object %d cannot be inserted into leases (%d)\n",
 449                                         object_id, ret);
 450                         goto out_free_objects;
 451                 }
 452                 if (obj->type == DRM_MODE_OBJECT_CRTC && !lessor_priv->universal_planes) {
 453                         struct drm_crtc *crtc = obj_to_crtc(obj);
 454                         ret = idr_alloc(leases, &drm_lease_idr_object, crtc->primary->base.id, crtc->primary->base.id + 1, GFP_KERNEL);
 455                         if (ret < 0) {
 456                                 DRM_DEBUG_LEASE("Object primary plane %d cannot be inserted into leases (%d)\n",
 457                                                 object_id, ret);
 458                                 goto out_free_objects;
 459                         }
 460                         if (crtc->cursor) {
 461                                 ret = idr_alloc(leases, &drm_lease_idr_object, crtc->cursor->base.id, crtc->cursor->base.id + 1, GFP_KERNEL);
 462                                 if (ret < 0) {
 463                                         DRM_DEBUG_LEASE("Object cursor plane %d cannot be inserted into leases (%d)\n",
 464                                                         object_id, ret);
 465                                         goto out_free_objects;
 466                                 }
 467                         }
 468                 }
 469         }
 470
 471         ret = 0;
 472 out_free_objects:
 473         for (o = 0; o < object_count; o++) {
 474                 if (objects[o])
 475                         drm_mode_object_put(objects[o]);
 476         }
 477         kfree(objects);
 478         return ret;
 479 }
 480
 481 /**
 482  * drm_mode_create_lease_ioctl - create a new lease
 483  * @dev: the drm device
 484  * @data: pointer to struct drm_mode_create_lease
 485  * @lessor_priv: the file being manipulated
 486  *
 487  * The master associated with the specified file will have a lease
 488  * created containing the objects specified in the ioctl structure.
 489  * A file descriptor will be allocated for that and returned to the
 490  * application.
 491  */
 492 int drm_mode_create_lease_ioctl(struct drm_device *dev,
 493                                 void *data, struct drm_file *lessor_priv)
 494 {
 495         struct drm_mode_create_lease *cl = data;
 496         size_t object_count;
 497         int ret = 0;
 498         struct idr leases;
 499         struct drm_master *lessor = lessor_priv->master;
 500         struct drm_master *lessee = NULL;
 501         struct file *lessee_file = NULL;
 502         struct file *lessor_file = lessor_priv->filp;
 503         struct drm_file *lessee_priv;
 504         int fd = -1;
 505         uint32_t *object_ids;
 506
 507         /* Can't lease without MODESET */
 508         if (!drm_core_check_feature(dev, DRIVER_MODESET))
 509                 return -EINVAL;
 510
 511         /* Do not allow sub-leases */
 512         if (lessor->lessor)
 513                 return -EINVAL;
 514
 515         /* need some objects */
 516         if (cl->object_count == 0)
 517                 return -EINVAL;
 518
 519         if (cl->flags && (cl->flags & ~(O_CLOEXEC | O_NONBLOCK)))
 520                 return -EINVAL;
 521
 522         object_count = cl->object_count;
 523
 524         object_ids = memdup_user(u64_to_user_ptr(cl->object_ids),
 525                         array_size(object_count, sizeof(__u32)));
 526         if (IS_ERR(object_ids))
 527                 return PTR_ERR(object_ids);
 528
 529         idr_init(&leases);
 530
 531         /* fill and validate the object idr */
 532         ret = fill_object_idr(dev, lessor_priv, &leases,
 533                               object_count, object_ids);
 534         kfree(object_ids);
 535         if (ret) {
 536                 idr_destroy(&leases);
 537                 return ret;
 538         }
 539
 540         /* Allocate a file descriptor for the lease */
 541         fd = get_unused_fd_flags(cl->flags & (O_CLOEXEC | O_NONBLOCK));
 542         if (fd < 0) {
 543                 idr_destroy(&leases);
 544                 return fd;
 545         }
 546
 547         DRM_DEBUG_LEASE("Creating lease\n");
 548         /* lessee will take the ownership of leases */
 549         lessee = drm_lease_create(lessor, &leases);
 550
 551         if (IS_ERR(lessee)) {
 552                 ret = PTR_ERR(lessee);
 553                 idr_destroy(&leases);
 554                 goto out_leases;
 555         }
 556
 557         /* Clone the lessor file to create a new file for us */
 558         DRM_DEBUG_LEASE("Allocating lease file\n");
 559         lessee_file = file_clone_open(lessor_file);
 560         if (IS_ERR(lessee_file)) {
 561                 ret = PTR_ERR(lessee_file);
 562                 goto out_lessee;
 563         }
 564
 565         lessee_priv = lessee_file->private_data;
 566         /* Change the file to a master one */
 567         drm_master_put(&lessee_priv->master);
 568         lessee_priv->master = lessee;
 569         lessee_priv->is_master = 1;
 570         lessee_priv->authenticated = 1;
 571
 572         /* Pass fd back to userspace */
 573         DRM_DEBUG_LEASE("Returning fd %d id %d\n", fd, lessee->lessee_id);
 574         cl->fd = fd;
 575         cl->lessee_id = lessee->lessee_id;
 576
 577         /* Hook up the fd */
 578         fd_install(fd, lessee_file);
 579
 580         DRM_DEBUG_LEASE("drm_mode_create_lease_ioctl succeeded\n");
 581         return 0;
 582
 583 out_lessee:
 584         drm_master_put(&lessee);
 585
 586 out_leases:
 587         put_unused_fd(fd);
 588
 589         DRM_DEBUG_LEASE("drm_mode_create_lease_ioctl failed: %d\n", ret);
 590         return ret;
 591 }
 592
 593 /**
 594  * drm_mode_list_lessees_ioctl - list lessee ids
 595  * @dev: the drm device
 596  * @data: pointer to struct drm_mode_list_lessees
 597  * @lessor_priv: the file being manipulated
 598  *
 599  * Starting from the master associated with the specified file,
 600  * the master with the provided lessee_id is found, and then
 601  * an array of lessee ids associated with leases from that master
 602  * are returned.
 603  */
 604
 605 int drm_mode_list_lessees_ioctl(struct drm_device *dev,
 606                                void *data, struct drm_file *lessor_priv)
 607 {
 608         struct drm_mode_list_lessees *arg = data;
 609         __u32 __user *lessee_ids = (__u32 __user *) (uintptr_t) (arg->lessees_ptr);
 610         __u32 count_lessees = arg->count_lessees;
 611         struct drm_master *lessor = lessor_priv->master, *lessee;
 612         int count;
 613         int ret = 0;
 614
 615         if (arg->pad)
 616                 return -EINVAL;
 617
 618         /* Can't lease without MODESET */
 619         if (!drm_core_check_feature(dev, DRIVER_MODESET))
 620                 return -EINVAL;
 621
 622         DRM_DEBUG_LEASE("List lessees for %d\n", lessor->lessee_id);
 623
 624         mutex_lock(&dev->mode_config.idr_mutex);
 625
 626         count = 0;
 627         drm_for_each_lessee(lessee, lessor) {
 628                 /* Only list un-revoked leases */
 629                 if (!idr_is_empty(&lessee->leases)) {
 630                         if (count_lessees > count) {
 631                                 DRM_DEBUG_LEASE("Add lessee %d\n", lessee->lessee_id);
 632                                 ret = put_user(lessee->lessee_id, lessee_ids + count);
 633                                 if (ret)
 634                                         break;
 635                         }
 636                         count++;
 637                 }
 638         }
 639
 640         DRM_DEBUG_LEASE("Lessor leases to %d\n", count);
 641         if (ret == 0)
 642                 arg->count_lessees = count;
 643
 644         mutex_unlock(&dev->mode_config.idr_mutex);
 645
 646         return ret;
 647 }
 648
 649 /**
 650  * drm_mode_get_lease_ioctl - list leased objects
 651  * @dev: the drm device
 652  * @data: pointer to struct drm_mode_get_lease
 653  * @lessee_priv: the file being manipulated
 654  *
 655  * Return the list of leased objects for the specified lessee
 656  */
 657
 658 int drm_mode_get_lease_ioctl(struct drm_device *dev,
 659                              void *data, struct drm_file *lessee_priv)
 660 {
 661         struct drm_mode_get_lease *arg = data;
 662         __u32 __user *object_ids = (__u32 __user *) (uintptr_t) (arg->objects_ptr);
 663         __u32 count_objects = arg->count_objects;
 664         struct drm_master *lessee = lessee_priv->master;
 665         struct idr *object_idr;
 666         int count;
 667         void *entry;
 668         int object;
 669         int ret = 0;
 670
 671         if (arg->pad)
 672                 return -EINVAL;
 673
 674         /* Can't lease without MODESET */
 675         if (!drm_core_check_feature(dev, DRIVER_MODESET))
 676                 return -EINVAL;
 677
 678         DRM_DEBUG_LEASE("get lease for %d\n", lessee->lessee_id);
 679
 680         mutex_lock(&dev->mode_config.idr_mutex);
 681
 682         if (lessee->lessor == NULL)
 683                 /* owner can use all objects */
 684                 object_idr = &lessee->dev->mode_config.crtc_idr;
 685         else
 686                 /* lessee can only use allowed object */
 687                 object_idr = &lessee->leases;
 688
 689         count = 0;
 690         idr_for_each_entry(object_idr, entry, object) {
 691                 if (count_objects > count) {
 692                         DRM_DEBUG_LEASE("adding object %d\n", object);
 693                         ret = put_user(object, object_ids + count);
 694                         if (ret)
 695                                 break;
 696                 }
 697                 count++;
 698         }
 699
 700         DRM_DEBUG("lease holds %d objects\n", count);
 701         if (ret == 0)
 702                 arg->count_objects = count;
 703
 704         mutex_unlock(&dev->mode_config.idr_mutex);
 705
 706         return ret;
 707 }
 708
 709 /**
 710  * drm_mode_revoke_lease_ioctl - revoke lease
 711  * @dev: the drm device
 712  * @data: pointer to struct drm_mode_revoke_lease
 713  * @lessor_priv: the file being manipulated
 714  *
 715  * This removes all of the objects from the lease without
 716  * actually getting rid of the lease itself; that way all
 717  * references to it still work correctly
 718  */
 719 int drm_mode_revoke_lease_ioctl(struct drm_device *dev,
 720                                 void *data, struct drm_file *lessor_priv)
 721 {
 722         struct drm_mode_revoke_lease *arg = data;
 723         struct drm_master *lessor = lessor_priv->master;
 724         struct drm_master *lessee;
 725         int ret = 0;
 726
 727         DRM_DEBUG_LEASE("revoke lease for %d\n", arg->lessee_id);
 728
 729         /* Can't lease without MODESET */
 730         if (!drm_core_check_feature(dev, DRIVER_MODESET))
 731                 return -EINVAL;
 732
 733         mutex_lock(&dev->mode_config.idr_mutex);
 734
 735         lessee = _drm_find_lessee(lessor, arg->lessee_id);
 736
 737         /* No such lessee */
 738         if (!lessee) {
 739                 ret = -ENOENT;
 740                 goto fail;
 741         }
 742
 743         /* Lease is not held by lessor */
 744         if (lessee->lessor != lessor) {
 745                 ret = -EACCES;
 746                 goto fail;
 747         }
 748
 749         _drm_lease_revoke(lessee);
 750
 751 fail:
 752         mutex_unlock(&dev->mode_config.idr_mutex);
 753
 754         return ret;
 755 }