drivers/gpu/drm/drm_syncobj.c

   1 /*
   2  * Copyright 2017 Red Hat
   3  * Parts ported from amdgpu (fence wait code).
   4  * Copyright 2016 Advanced Micro Devices, Inc.
   5  *
   6  * Permission is hereby granted, free of charge, to any person obtaining a
   7  * copy of this software and associated documentation files (the "Software"),
   8  * to deal in the Software without restriction, including without limitation
   9  * the rights to use, copy, modify, merge, publish, distribute, sublicense,
  10  * and/or sell copies of the Software, and to permit persons to whom the
  11  * Software is furnished to do so, subject to the following conditions:
  12  *
  13  * The above copyright notice and this permission notice (including the next
  14  * paragraph) shall be included in all copies or substantial portions of the
  15  * Software.
  16  *
  17  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
  18  * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
  19  * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL
  20  * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
  21  * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
  22  * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS
  23  * IN THE SOFTWARE.
  24  *
  25  * Authors:
  26  *
  27  */
  28
  29 /**
  30  * DOC: Overview
  31  *
  32  * DRM synchronisation objects (syncobj, see struct &drm_syncobj) are
  33  * persistent objects that contain an optional fence. The fence can be updated
  34  * with a new fence, or be NULL.
  35  *
  36  * syncobj's can be waited upon, where it will wait for the underlying
  37  * fence.
  38  *
  39  * syncobj's can be export to fd's and back, these fd's are opaque and
  40  * have no other use case, except passing the syncobj between processes.
  41  *
  42  * Their primary use-case is to implement Vulkan fences and semaphores.
  43  *
  44  * syncobj have a kref reference count, but also have an optional file.
  45  * The file is only created once the syncobj is exported.
  46  * The file takes a reference on the kref.
  47  */
  48
  49 #include <drm/drmP.h>
  50 #include <linux/file.h>
  51 #include <linux/fs.h>
  52 #include <linux/anon_inodes.h>
  53 #include <linux/sync_file.h>
  54 #include <linux/sched/signal.h>
  55
  56 #include "drm_internal.h"
  57 #include <drm/drm_syncobj.h>
  58
  59 struct syncobj_wait_entry {
  60         struct list_head node;
  61         struct task_struct *task;
  62         struct dma_fence *fence;
  63         struct dma_fence_cb fence_cb;
  64 };
  65
  66 static void syncobj_wait_syncobj_func(struct drm_syncobj *syncobj,
  67                                       struct syncobj_wait_entry *wait);
  68
  69 /**
  70  * drm_syncobj_find - lookup and reference a sync object.
  71  * @file_private: drm file private pointer
  72  * @handle: sync object handle to lookup.
  73  *
  74  * Returns a reference to the syncobj pointed to by handle or NULL. The
  75  * reference must be released by calling drm_syncobj_put().
  76  */
  77 struct drm_syncobj *drm_syncobj_find(struct drm_file *file_private,
  78                                      u32 handle)
  79 {
  80         struct drm_syncobj *syncobj;
  81
  82         spin_lock(&file_private->syncobj_table_lock);
  83
  84         /* Check if we currently have a reference on the object */
  85         syncobj = idr_find(&file_private->syncobj_idr, handle);
  86         if (syncobj)
  87                 drm_syncobj_get(syncobj);
  88
  89         spin_unlock(&file_private->syncobj_table_lock);
  90
  91         return syncobj;
  92 }
  93 EXPORT_SYMBOL(drm_syncobj_find);
  94
  95 static void drm_syncobj_fence_add_wait(struct drm_syncobj *syncobj,
  96                                        struct syncobj_wait_entry *wait)
  97 {
  98         if (wait->fence)
  99                 return;
 100
 101         spin_lock(&syncobj->lock);
 102         /* We've already tried once to get a fence and failed.  Now that we
 103          * have the lock, try one more time just to be sure we don't add a
 104          * callback when a fence has already been set.
 105          */
 106         if (syncobj->fence)
 107                 wait->fence = dma_fence_get(
 108                         rcu_dereference_protected(syncobj->fence, 1));
 109         else
 110                 list_add_tail(&wait->node, &syncobj->cb_list);
 111         spin_unlock(&syncobj->lock);
 112 }
 113
 114 static void drm_syncobj_remove_wait(struct drm_syncobj *syncobj,
 115                                     struct syncobj_wait_entry *wait)
 116 {
 117         if (!wait->node.next)
 118                 return;
 119
 120         spin_lock(&syncobj->lock);
 121         list_del_init(&wait->node);
 122         spin_unlock(&syncobj->lock);
 123 }
 124
 125 /**
 126  * drm_syncobj_add_point - add new timeline point to the syncobj
 127  * @syncobj: sync object to add timeline point do
 128  * @chain: chain node to use to add the point
 129  * @fence: fence to encapsulate in the chain node
 130  * @point: sequence number to use for the point
 131  *
 132  * Add the chain node as new timeline point to the syncobj.
 133  */
 134 void drm_syncobj_add_point(struct drm_syncobj *syncobj,
 135                            struct dma_fence_chain *chain,
 136                            struct dma_fence *fence,
 137                            uint64_t point)
 138 {
 139         struct syncobj_wait_entry *cur, *tmp;
 140         struct dma_fence *prev;
 141
 142         dma_fence_get(fence);
 143
 144         spin_lock(&syncobj->lock);
 145
 146         prev = drm_syncobj_fence_get(syncobj);
 147         /* You are adding an unorder point to timeline, which could cause payload returned from query_ioctl is 0! */
 148         if (prev && prev->seqno >= point)
 149                 DRM_ERROR("You are adding an unorder point to timeline!\n");
 150         dma_fence_chain_init(chain, prev, fence, point);
 151         rcu_assign_pointer(syncobj->fence, &chain->base);
 152
 153         list_for_each_entry_safe(cur, tmp, &syncobj->cb_list, node) {
 154                 list_del_init(&cur->node);
 155                 syncobj_wait_syncobj_func(syncobj, cur);
 156         }
 157         spin_unlock(&syncobj->lock);
 158
 159         /* Walk the chain once to trigger garbage collection */
 160         dma_fence_chain_for_each(fence, prev);
 161         dma_fence_put(prev);
 162 }
 163 EXPORT_SYMBOL(drm_syncobj_add_point);
 164
 165 /**
 166  * drm_syncobj_replace_fence - replace fence in a sync object.
 167  * @syncobj: Sync object to replace fence in
 168  * @fence: fence to install in sync file.
 169  *
 170  * This replaces the fence on a sync object.
 171  */
 172 void drm_syncobj_replace_fence(struct drm_syncobj *syncobj,
 173                                struct dma_fence *fence)
 174 {
 175         struct dma_fence *old_fence;
 176         struct syncobj_wait_entry *cur, *tmp;
 177
 178         if (fence)
 179                 dma_fence_get(fence);
 180
 181         spin_lock(&syncobj->lock);
 182
 183         old_fence = rcu_dereference_protected(syncobj->fence,
 184                                               lockdep_is_held(&syncobj->lock));
 185         rcu_assign_pointer(syncobj->fence, fence);
 186
 187         if (fence != old_fence) {
 188                 list_for_each_entry_safe(cur, tmp, &syncobj->cb_list, node) {
 189                         list_del_init(&cur->node);
 190                         syncobj_wait_syncobj_func(syncobj, cur);
 191                 }
 192         }
 193
 194         spin_unlock(&syncobj->lock);
 195
 196         dma_fence_put(old_fence);
 197 }
 198 EXPORT_SYMBOL(drm_syncobj_replace_fence);
 199
 200 /**
 201  * drm_syncobj_assign_null_handle - assign a stub fence to the sync object
 202  * @syncobj: sync object to assign the fence on
 203  *
 204  * Assign a already signaled stub fence to the sync object.
 205  */
 206 static void drm_syncobj_assign_null_handle(struct drm_syncobj *syncobj)
 207 {
 208         struct dma_fence *fence = dma_fence_get_stub();
 209
 210         drm_syncobj_replace_fence(syncobj, fence);
 211         dma_fence_put(fence);
 212 }
 213
 214 /**
 215  * drm_syncobj_find_fence - lookup and reference the fence in a sync object
 216  * @file_private: drm file private pointer
 217  * @handle: sync object handle to lookup.
 218  * @point: timeline point
 219  * @flags: DRM_SYNCOBJ_WAIT_FLAGS_WAIT_FOR_SUBMIT or not
 220  * @fence: out parameter for the fence
 221  *
 222  * This is just a convenience function that combines drm_syncobj_find() and
 223  * drm_syncobj_fence_get().
 224  *
 225  * Returns 0 on success or a negative error value on failure. On success @fence
 226  * contains a reference to the fence, which must be released by calling
 227  * dma_fence_put().
 228  */
 229 int drm_syncobj_find_fence(struct drm_file *file_private,
 230                            u32 handle, u64 point, u64 flags,
 231                            struct dma_fence **fence)
 232 {
 233         struct drm_syncobj *syncobj = drm_syncobj_find(file_private, handle);
 234         int ret = 0;
 235
 236         if (!syncobj)
 237                 return -ENOENT;
 238
 239         *fence = drm_syncobj_fence_get(syncobj);
 240         if (!*fence) {
 241                 ret = -EINVAL;
 242         }
 243         drm_syncobj_put(syncobj);
 244         return ret;
 245 }
 246 EXPORT_SYMBOL(drm_syncobj_find_fence);
 247
 248 /**
 249  * drm_syncobj_free - free a sync object.
 250  * @kref: kref to free.
 251  *
 252  * Only to be called from kref_put in drm_syncobj_put.
 253  */
 254 void drm_syncobj_free(struct kref *kref)
 255 {
 256         struct drm_syncobj *syncobj = container_of(kref,
 257                                                    struct drm_syncobj,
 258                                                    refcount);
 259         drm_syncobj_replace_fence(syncobj, NULL);
 260         kfree(syncobj);
 261 }
 262 EXPORT_SYMBOL(drm_syncobj_free);
 263
 264 /**
 265  * drm_syncobj_create - create a new syncobj
 266  * @out_syncobj: returned syncobj
 267  * @flags: DRM_SYNCOBJ_* flags
 268  * @fence: if non-NULL, the syncobj will represent this fence
 269  *
 270  * This is the first function to create a sync object. After creating, drivers
 271  * probably want to make it available to userspace, either through
 272  * drm_syncobj_get_handle() or drm_syncobj_get_fd().
 273  *
 274  * Returns 0 on success or a negative error value on failure.
 275  */
 276 int drm_syncobj_create(struct drm_syncobj **out_syncobj, uint32_t flags,
 277                        struct dma_fence *fence)
 278 {
 279         struct drm_syncobj *syncobj;
 280
 281         syncobj = kzalloc(sizeof(struct drm_syncobj), GFP_KERNEL);
 282         if (!syncobj)
 283                 return -ENOMEM;
 284
 285         kref_init(&syncobj->refcount);
 286         INIT_LIST_HEAD(&syncobj->cb_list);
 287         spin_lock_init(&syncobj->lock);
 288
 289         if (flags & DRM_SYNCOBJ_CREATE_SIGNALED)
 290                 drm_syncobj_assign_null_handle(syncobj);
 291
 292         if (fence)
 293                 drm_syncobj_replace_fence(syncobj, fence);
 294
 295         *out_syncobj = syncobj;
 296         return 0;
 297 }
 298 EXPORT_SYMBOL(drm_syncobj_create);
 299
 300 /**
 301  * drm_syncobj_get_handle - get a handle from a syncobj
 302  * @file_private: drm file private pointer
 303  * @syncobj: Sync object to export
 304  * @handle: out parameter with the new handle
 305  *
 306  * Exports a sync object created with drm_syncobj_create() as a handle on
 307  * @file_private to userspace.
 308  *
 309  * Returns 0 on success or a negative error value on failure.
 310  */
 311 int drm_syncobj_get_handle(struct drm_file *file_private,
 312                            struct drm_syncobj *syncobj, u32 *handle)
 313 {
 314         int ret;
 315
 316         /* take a reference to put in the idr */
 317         drm_syncobj_get(syncobj);
 318
 319         idr_preload(GFP_KERNEL);
 320         spin_lock(&file_private->syncobj_table_lock);
 321         ret = idr_alloc(&file_private->syncobj_idr, syncobj, 1, 0, GFP_NOWAIT);
 322         spin_unlock(&file_private->syncobj_table_lock);
 323
 324         idr_preload_end();
 325
 326         if (ret < 0) {
 327                 drm_syncobj_put(syncobj);
 328                 return ret;
 329         }
 330
 331         *handle = ret;
 332         return 0;
 333 }
 334 EXPORT_SYMBOL(drm_syncobj_get_handle);
 335
 336 static int drm_syncobj_create_as_handle(struct drm_file *file_private,
 337                                         u32 *handle, uint32_t flags)
 338 {
 339         int ret;
 340         struct drm_syncobj *syncobj;
 341
 342         ret = drm_syncobj_create(&syncobj, flags, NULL);
 343         if (ret)
 344                 return ret;
 345
 346         ret = drm_syncobj_get_handle(file_private, syncobj, handle);
 347         drm_syncobj_put(syncobj);
 348         return ret;
 349 }
 350
 351 static int drm_syncobj_destroy(struct drm_file *file_private,
 352                                u32 handle)
 353 {
 354         struct drm_syncobj *syncobj;
 355
 356         spin_lock(&file_private->syncobj_table_lock);
 357         syncobj = idr_remove(&file_private->syncobj_idr, handle);
 358         spin_unlock(&file_private->syncobj_table_lock);
 359
 360         if (!syncobj)
 361                 return -EINVAL;
 362
 363         drm_syncobj_put(syncobj);
 364         return 0;
 365 }
 366
 367 static int drm_syncobj_file_release(struct inode *inode, struct file *file)
 368 {
 369         struct drm_syncobj *syncobj = file->private_data;
 370
 371         drm_syncobj_put(syncobj);
 372         return 0;
 373 }
 374
 375 static const struct file_operations drm_syncobj_file_fops = {
 376         .release = drm_syncobj_file_release,
 377 };
 378
 379 /**
 380  * drm_syncobj_get_fd - get a file descriptor from a syncobj
 381  * @syncobj: Sync object to export
 382  * @p_fd: out parameter with the new file descriptor
 383  *
 384  * Exports a sync object created with drm_syncobj_create() as a file descriptor.
 385  *
 386  * Returns 0 on success or a negative error value on failure.
 387  */
 388 int drm_syncobj_get_fd(struct drm_syncobj *syncobj, int *p_fd)
 389 {
 390         struct file *file;
 391         int fd;
 392
 393         fd = get_unused_fd_flags(O_CLOEXEC);
 394         if (fd < 0)
 395                 return fd;
 396
 397         file = anon_inode_getfile("syncobj_file",
 398                                   &drm_syncobj_file_fops,
 399                                   syncobj, 0);
 400         if (IS_ERR(file)) {
 401                 put_unused_fd(fd);
 402                 return PTR_ERR(file);
 403         }
 404
 405         drm_syncobj_get(syncobj);
 406         fd_install(fd, file);
 407
 408         *p_fd = fd;
 409         return 0;
 410 }
 411 EXPORT_SYMBOL(drm_syncobj_get_fd);
 412
 413 static int drm_syncobj_handle_to_fd(struct drm_file *file_private,
 414                                     u32 handle, int *p_fd)
 415 {
 416         struct drm_syncobj *syncobj = drm_syncobj_find(file_private, handle);
 417         int ret;
 418
 419         if (!syncobj)
 420                 return -EINVAL;
 421
 422         ret = drm_syncobj_get_fd(syncobj, p_fd);
 423         drm_syncobj_put(syncobj);
 424         return ret;
 425 }
 426
 427 static int drm_syncobj_fd_to_handle(struct drm_file *file_private,
 428                                     int fd, u32 *handle)
 429 {
 430         struct drm_syncobj *syncobj;
 431         struct file *file;
 432         int ret;
 433
 434         file = fget(fd);
 435         if (!file)
 436                 return -EINVAL;
 437
 438         if (file->f_op != &drm_syncobj_file_fops) {
 439                 fput(file);
 440                 return -EINVAL;
 441         }
 442
 443         /* take a reference to put in the idr */
 444         syncobj = file->private_data;
 445         drm_syncobj_get(syncobj);
 446
 447         idr_preload(GFP_KERNEL);
 448         spin_lock(&file_private->syncobj_table_lock);
 449         ret = idr_alloc(&file_private->syncobj_idr, syncobj, 1, 0, GFP_NOWAIT);
 450         spin_unlock(&file_private->syncobj_table_lock);
 451         idr_preload_end();
 452
 453         if (ret > 0) {
 454                 *handle = ret;
 455                 ret = 0;
 456         } else
 457                 drm_syncobj_put(syncobj);
 458
 459         fput(file);
 460         return ret;
 461 }
 462
 463 static int drm_syncobj_import_sync_file_fence(struct drm_file *file_private,
 464                                               int fd, int handle)
 465 {
 466         struct dma_fence *fence = sync_file_get_fence(fd);
 467         struct drm_syncobj *syncobj;
 468
 469         if (!fence)
 470                 return -EINVAL;
 471
 472         syncobj = drm_syncobj_find(file_private, handle);
 473         if (!syncobj) {
 474                 dma_fence_put(fence);
 475                 return -ENOENT;
 476         }
 477
 478         drm_syncobj_replace_fence(syncobj, fence);
 479         dma_fence_put(fence);
 480         drm_syncobj_put(syncobj);
 481         return 0;
 482 }
 483
 484 static int drm_syncobj_export_sync_file(struct drm_file *file_private,
 485                                         int handle, int *p_fd)
 486 {
 487         int ret;
 488         struct dma_fence *fence;
 489         struct sync_file *sync_file;
 490         int fd = get_unused_fd_flags(O_CLOEXEC);
 491
 492         if (fd < 0)
 493                 return fd;
 494
 495         ret = drm_syncobj_find_fence(file_private, handle, 0, 0, &fence);
 496         if (ret)
 497                 goto err_put_fd;
 498
 499         sync_file = sync_file_create(fence);
 500
 501         dma_fence_put(fence);
 502
 503         if (!sync_file) {
 504                 ret = -EINVAL;
 505                 goto err_put_fd;
 506         }
 507
 508         fd_install(fd, sync_file->file);
 509
 510         *p_fd = fd;
 511         return 0;
 512 err_put_fd:
 513         put_unused_fd(fd);
 514         return ret;
 515 }
 516 /**
 517  * drm_syncobj_open - initalizes syncobj file-private structures at devnode open time
 518  * @file_private: drm file-private structure to set up
 519  *
 520  * Called at device open time, sets up the structure for handling refcounting
 521  * of sync objects.
 522  */
 523 void
 524 drm_syncobj_open(struct drm_file *file_private)
 525 {
 526         idr_init_base(&file_private->syncobj_idr, 1);
 527         spin_lock_init(&file_private->syncobj_table_lock);
 528 }
 529
 530 static int
 531 drm_syncobj_release_handle(int id, void *ptr, void *data)
 532 {
 533         struct drm_syncobj *syncobj = ptr;
 534
 535         drm_syncobj_put(syncobj);
 536         return 0;
 537 }
 538
 539 /**
 540  * drm_syncobj_release - release file-private sync object resources
 541  * @file_private: drm file-private structure to clean up
 542  *
 543  * Called at close time when the filp is going away.
 544  *
 545  * Releases any remaining references on objects by this filp.
 546  */
 547 void
 548 drm_syncobj_release(struct drm_file *file_private)
 549 {
 550         idr_for_each(&file_private->syncobj_idr,
 551                      &drm_syncobj_release_handle, file_private);
 552         idr_destroy(&file_private->syncobj_idr);
 553 }
 554
 555 int
 556 drm_syncobj_create_ioctl(struct drm_device *dev, void *data,
 557                          struct drm_file *file_private)
 558 {
 559         struct drm_syncobj_create *args = data;
 560
 561         if (!drm_core_check_feature(dev, DRIVER_SYNCOBJ))
 562                 return -EOPNOTSUPP;
 563
 564         /* no valid flags yet */
 565         if (args->flags & ~DRM_SYNCOBJ_CREATE_SIGNALED)
 566                 return -EINVAL;
 567
 568         return drm_syncobj_create_as_handle(file_private,
 569                                             &args->handle, args->flags);
 570 }
 571
 572 int
 573 drm_syncobj_destroy_ioctl(struct drm_device *dev, void *data,
 574                           struct drm_file *file_private)
 575 {
 576         struct drm_syncobj_destroy *args = data;
 577
 578         if (!drm_core_check_feature(dev, DRIVER_SYNCOBJ))
 579                 return -EOPNOTSUPP;
 580
 581         /* make sure padding is empty */
 582         if (args->pad)
 583                 return -EINVAL;
 584         return drm_syncobj_destroy(file_private, args->handle);
 585 }
 586
 587 int
 588 drm_syncobj_handle_to_fd_ioctl(struct drm_device *dev, void *data,
 589                                    struct drm_file *file_private)
 590 {
 591         struct drm_syncobj_handle *args = data;
 592
 593         if (!drm_core_check_feature(dev, DRIVER_SYNCOBJ))
 594                 return -EOPNOTSUPP;
 595
 596         if (args->pad)
 597                 return -EINVAL;
 598
 599         if (args->flags != 0 &&
 600             args->flags != DRM_SYNCOBJ_HANDLE_TO_FD_FLAGS_EXPORT_SYNC_FILE)
 601                 return -EINVAL;
 602
 603         if (args->flags & DRM_SYNCOBJ_HANDLE_TO_FD_FLAGS_EXPORT_SYNC_FILE)
 604                 return drm_syncobj_export_sync_file(file_private, args->handle,
 605                                                     &args->fd);
 606
 607         return drm_syncobj_handle_to_fd(file_private, args->handle,
 608                                         &args->fd);
 609 }
 610
 611 int
 612 drm_syncobj_fd_to_handle_ioctl(struct drm_device *dev, void *data,
 613                                    struct drm_file *file_private)
 614 {
 615         struct drm_syncobj_handle *args = data;
 616
 617         if (!drm_core_check_feature(dev, DRIVER_SYNCOBJ))
 618                 return -EOPNOTSUPP;
 619
 620         if (args->pad)
 621                 return -EINVAL;
 622
 623         if (args->flags != 0 &&
 624             args->flags != DRM_SYNCOBJ_FD_TO_HANDLE_FLAGS_IMPORT_SYNC_FILE)
 625                 return -EINVAL;
 626
 627         if (args->flags & DRM_SYNCOBJ_FD_TO_HANDLE_FLAGS_IMPORT_SYNC_FILE)
 628                 return drm_syncobj_import_sync_file_fence(file_private,
 629                                                           args->fd,
 630                                                           args->handle);
 631
 632         return drm_syncobj_fd_to_handle(file_private, args->fd,
 633                                         &args->handle);
 634 }
 635
 636 static void syncobj_wait_fence_func(struct dma_fence *fence,
 637                                     struct dma_fence_cb *cb)
 638 {
 639         struct syncobj_wait_entry *wait =
 640                 container_of(cb, struct syncobj_wait_entry, fence_cb);
 641
 642         wake_up_process(wait->task);
 643 }
 644
 645 static void syncobj_wait_syncobj_func(struct drm_syncobj *syncobj,
 646                                       struct syncobj_wait_entry *wait)
 647 {
 648         /* This happens inside the syncobj lock */
 649         wait->fence = dma_fence_get(rcu_dereference_protected(syncobj->fence,
 650                                                               lockdep_is_held(&syncobj->lock)));
 651         wake_up_process(wait->task);
 652 }
 653
 654 static signed long drm_syncobj_array_wait_timeout(struct drm_syncobj **syncobjs,
 655                                                   uint32_t count,
 656                                                   uint32_t flags,
 657                                                   signed long timeout,
 658                                                   uint32_t *idx)
 659 {
 660         struct syncobj_wait_entry *entries;
 661         struct dma_fence *fence;
 662         uint32_t signaled_count, i;
 663
 664         entries = kcalloc(count, sizeof(*entries), GFP_KERNEL);
 665         if (!entries)
 666                 return -ENOMEM;
 667
 668         /* Walk the list of sync objects and initialize entries.  We do
 669          * this up-front so that we can properly return -EINVAL if there is
 670          * a syncobj with a missing fence and then never have the chance of
 671          * returning -EINVAL again.
 672          */
 673         signaled_count = 0;
 674         for (i = 0; i < count; ++i) {
 675                 entries[i].task = current;
 676                 entries[i].fence = drm_syncobj_fence_get(syncobjs[i]);
 677                 if (!entries[i].fence) {
 678                         if (flags & DRM_SYNCOBJ_WAIT_FLAGS_WAIT_FOR_SUBMIT) {
 679                                 continue;
 680                         } else {
 681                                 timeout = -EINVAL;
 682                                 goto cleanup_entries;
 683                         }
 684                 }
 685
 686                 if (dma_fence_is_signaled(entries[i].fence)) {
 687                         if (signaled_count == 0 && idx)
 688                                 *idx = i;
 689                         signaled_count++;
 690                 }
 691         }
 692
 693         if (signaled_count == count ||
 694             (signaled_count > 0 &&
 695              !(flags & DRM_SYNCOBJ_WAIT_FLAGS_WAIT_ALL)))
 696                 goto cleanup_entries;
 697
 698         /* There's a very annoying laxness in the dma_fence API here, in
 699          * that backends are not required to automatically report when a
 700          * fence is signaled prior to fence->ops->enable_signaling() being
 701          * called.  So here if we fail to match signaled_count, we need to
 702          * fallthough and try a 0 timeout wait!
 703          */
 704
 705         if (flags & DRM_SYNCOBJ_WAIT_FLAGS_WAIT_FOR_SUBMIT) {
 706                 for (i = 0; i < count; ++i)
 707                         drm_syncobj_fence_add_wait(syncobjs[i], &entries[i]);
 708         }
 709
 710         do {
 711                 set_current_state(TASK_INTERRUPTIBLE);
 712
 713                 signaled_count = 0;
 714                 for (i = 0; i < count; ++i) {
 715                         fence = entries[i].fence;
 716                         if (!fence)
 717                                 continue;
 718
 719                         if (dma_fence_is_signaled(fence) ||
 720                             (!entries[i].fence_cb.func &&
 721                              dma_fence_add_callback(fence,
 722                                                     &entries[i].fence_cb,
 723                                                     syncobj_wait_fence_func))) {
 724                                 /* The fence has been signaled */
 725                                 if (flags & DRM_SYNCOBJ_WAIT_FLAGS_WAIT_ALL) {
 726                                         signaled_count++;
 727                                 } else {
 728                                         if (idx)
 729                                                 *idx = i;
 730                                         goto done_waiting;
 731                                 }
 732                         }
 733                 }
 734
 735                 if (signaled_count == count)
 736                         goto done_waiting;
 737
 738                 if (timeout == 0) {
 739                         timeout = -ETIME;
 740                         goto done_waiting;
 741                 }
 742
 743                 if (signal_pending(current)) {
 744                         timeout = -ERESTARTSYS;
 745                         goto done_waiting;
 746                 }
 747
 748                 timeout = schedule_timeout(timeout);
 749         } while (1);
 750
 751 done_waiting:
 752         __set_current_state(TASK_RUNNING);
 753
 754 cleanup_entries:
 755         for (i = 0; i < count; ++i) {
 756                 drm_syncobj_remove_wait(syncobjs[i], &entries[i]);
 757                 if (entries[i].fence_cb.func)
 758                         dma_fence_remove_callback(entries[i].fence,
 759                                                   &entries[i].fence_cb);
 760                 dma_fence_put(entries[i].fence);
 761         }
 762         kfree(entries);
 763
 764         return timeout;
 765 }
 766
 767 /**
 768  * drm_timeout_abs_to_jiffies - calculate jiffies timeout from absolute value
 769  *
 770  * @timeout_nsec: timeout nsec component in ns, 0 for poll
 771  *
 772  * Calculate the timeout in jiffies from an absolute time in sec/nsec.
 773  */
 774 signed long drm_timeout_abs_to_jiffies(int64_t timeout_nsec)
 775 {
 776         ktime_t abs_timeout, now;
 777         u64 timeout_ns, timeout_jiffies64;
 778
 779         /* make 0 timeout means poll - absolute 0 doesn't seem valid */
 780         if (timeout_nsec == 0)
 781                 return 0;
 782
 783         abs_timeout = ns_to_ktime(timeout_nsec);
 784         now = ktime_get();
 785
 786         if (!ktime_after(abs_timeout, now))
 787                 return 0;
 788
 789         timeout_ns = ktime_to_ns(ktime_sub(abs_timeout, now));
 790
 791         timeout_jiffies64 = nsecs_to_jiffies64(timeout_ns);
 792         /*  clamp timeout to avoid infinite timeout */
 793         if (timeout_jiffies64 >= MAX_SCHEDULE_TIMEOUT - 1)
 794                 return MAX_SCHEDULE_TIMEOUT - 1;
 795
 796         return timeout_jiffies64 + 1;
 797 }
 798 EXPORT_SYMBOL(drm_timeout_abs_to_jiffies);
 799
 800 static int drm_syncobj_array_wait(struct drm_device *dev,
 801                                   struct drm_file *file_private,
 802                                   struct drm_syncobj_wait *wait,
 803                                   struct drm_syncobj **syncobjs)
 804 {
 805         signed long timeout = drm_timeout_abs_to_jiffies(wait->timeout_nsec);
 806         uint32_t first = ~0;
 807
 808         timeout = drm_syncobj_array_wait_timeout(syncobjs,
 809                                                  wait->count_handles,
 810                                                  wait->flags,
 811                                                  timeout, &first);
 812         if (timeout < 0)
 813                 return timeout;
 814
 815         wait->first_signaled = first;
 816         return 0;
 817 }
 818
 819 static int drm_syncobj_array_find(struct drm_file *file_private,
 820                                   void __user *user_handles,
 821                                   uint32_t count_handles,
 822                                   struct drm_syncobj ***syncobjs_out)
 823 {
 824         uint32_t i, *handles;
 825         struct drm_syncobj **syncobjs;
 826         int ret;
 827
 828         handles = kmalloc_array(count_handles, sizeof(*handles), GFP_KERNEL);
 829         if (handles == NULL)
 830                 return -ENOMEM;
 831
 832         if (copy_from_user(handles, user_handles,
 833                            sizeof(uint32_t) * count_handles)) {
 834                 ret = -EFAULT;
 835                 goto err_free_handles;
 836         }
 837
 838         syncobjs = kmalloc_array(count_handles, sizeof(*syncobjs), GFP_KERNEL);
 839         if (syncobjs == NULL) {
 840                 ret = -ENOMEM;
 841                 goto err_free_handles;
 842         }
 843
 844         for (i = 0; i < count_handles; i++) {
 845                 syncobjs[i] = drm_syncobj_find(file_private, handles[i]);
 846                 if (!syncobjs[i]) {
 847                         ret = -ENOENT;
 848                         goto err_put_syncobjs;
 849                 }
 850         }
 851
 852         kfree(handles);
 853         *syncobjs_out = syncobjs;
 854         return 0;
 855
 856 err_put_syncobjs:
 857         while (i-- > 0)
 858                 drm_syncobj_put(syncobjs[i]);
 859         kfree(syncobjs);
 860 err_free_handles:
 861         kfree(handles);
 862
 863         return ret;
 864 }
 865
 866 static void drm_syncobj_array_free(struct drm_syncobj **syncobjs,
 867                                    uint32_t count)
 868 {
 869         uint32_t i;
 870         for (i = 0; i < count; i++)
 871                 drm_syncobj_put(syncobjs[i]);
 872         kfree(syncobjs);
 873 }
 874
 875 int
 876 drm_syncobj_wait_ioctl(struct drm_device *dev, void *data,
 877                        struct drm_file *file_private)
 878 {
 879         struct drm_syncobj_wait *args = data;
 880         struct drm_syncobj **syncobjs;
 881         int ret = 0;
 882
 883         if (!drm_core_check_feature(dev, DRIVER_SYNCOBJ))
 884                 return -EOPNOTSUPP;
 885
 886         if (args->flags & ~(DRM_SYNCOBJ_WAIT_FLAGS_WAIT_ALL |
 887                             DRM_SYNCOBJ_WAIT_FLAGS_WAIT_FOR_SUBMIT))
 888                 return -EINVAL;
 889
 890         if (args->count_handles == 0)
 891                 return -EINVAL;
 892
 893         ret = drm_syncobj_array_find(file_private,
 894                                      u64_to_user_ptr(args->handles),
 895                                      args->count_handles,
 896                                      &syncobjs);
 897         if (ret < 0)
 898                 return ret;
 899
 900         ret = drm_syncobj_array_wait(dev, file_private,
 901                                      args, syncobjs);
 902
 903         drm_syncobj_array_free(syncobjs, args->count_handles);
 904
 905         return ret;
 906 }
 907
 908 int
 909 drm_syncobj_reset_ioctl(struct drm_device *dev, void *data,
 910                         struct drm_file *file_private)
 911 {
 912         struct drm_syncobj_array *args = data;
 913         struct drm_syncobj **syncobjs;
 914         uint32_t i;
 915         int ret;
 916
 917         if (!drm_core_check_feature(dev, DRIVER_SYNCOBJ))
 918                 return -EOPNOTSUPP;
 919
 920         if (args->pad != 0)
 921                 return -EINVAL;
 922
 923         if (args->count_handles == 0)
 924                 return -EINVAL;
 925
 926         ret = drm_syncobj_array_find(file_private,
 927                                      u64_to_user_ptr(args->handles),
 928                                      args->count_handles,
 929                                      &syncobjs);
 930         if (ret < 0)
 931                 return ret;
 932
 933         for (i = 0; i < args->count_handles; i++)
 934                 drm_syncobj_replace_fence(syncobjs[i], NULL);
 935
 936         drm_syncobj_array_free(syncobjs, args->count_handles);
 937
 938         return 0;
 939 }
 940
 941 int
 942 drm_syncobj_signal_ioctl(struct drm_device *dev, void *data,
 943                          struct drm_file *file_private)
 944 {
 945         struct drm_syncobj_array *args = data;
 946         struct drm_syncobj **syncobjs;
 947         uint32_t i;
 948         int ret;
 949
 950         if (!drm_core_check_feature(dev, DRIVER_SYNCOBJ))
 951                 return -EOPNOTSUPP;
 952
 953         if (args->pad != 0)
 954                 return -EINVAL;
 955
 956         if (args->count_handles == 0)
 957                 return -EINVAL;
 958
 959         ret = drm_syncobj_array_find(file_private,
 960                                      u64_to_user_ptr(args->handles),
 961                                      args->count_handles,
 962                                      &syncobjs);
 963         if (ret < 0)
 964                 return ret;
 965
 966         for (i = 0; i < args->count_handles; i++)
 967                 drm_syncobj_assign_null_handle(syncobjs[i]);
 968
 969         drm_syncobj_array_free(syncobjs, args->count_handles);
 970
 971         return ret;
 972 }