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 /**
  60  * drm_syncobj_find - lookup and reference a sync object.
  61  * @file_private: drm file private pointer
  62  * @handle: sync object handle to lookup.
  63  *
  64  * Returns a reference to the syncobj pointed to by handle or NULL. The
  65  * reference must be released by calling drm_syncobj_put().
  66  */
  67 struct drm_syncobj *drm_syncobj_find(struct drm_file *file_private,
  68                                      u32 handle)
  69 {
  70         struct drm_syncobj *syncobj;
  71
  72         spin_lock(&file_private->syncobj_table_lock);
  73
  74         /* Check if we currently have a reference on the object */
  75         syncobj = idr_find(&file_private->syncobj_idr, handle);
  76         if (syncobj)
  77                 drm_syncobj_get(syncobj);
  78
  79         spin_unlock(&file_private->syncobj_table_lock);
  80
  81         return syncobj;
  82 }
  83 EXPORT_SYMBOL(drm_syncobj_find);
  84
  85 static void drm_syncobj_add_callback_locked(struct drm_syncobj *syncobj,
  86                                             struct drm_syncobj_cb *cb,
  87                                             drm_syncobj_func_t func)
  88 {
  89         cb->func = func;
  90         list_add_tail(&cb->node, &syncobj->cb_list);
  91 }
  92
  93 static int drm_syncobj_fence_get_or_add_callback(struct drm_syncobj *syncobj,
  94                                                  struct dma_fence **fence,
  95                                                  struct drm_syncobj_cb *cb,
  96                                                  drm_syncobj_func_t func)
  97 {
  98         int ret;
  99
 100         *fence = drm_syncobj_fence_get(syncobj);
 101         if (*fence)
 102                 return 1;
 103
 104         spin_lock(&syncobj->lock);
 105         /* We've already tried once to get a fence and failed.  Now that we
 106          * have the lock, try one more time just to be sure we don't add a
 107          * callback when a fence has already been set.
 108          */
 109         if (syncobj->fence) {
 110                 *fence = dma_fence_get(rcu_dereference_protected(syncobj->fence,
 111                                                                  lockdep_is_held(&syncobj->lock)));
 112                 ret = 1;
 113         } else {
 114                 *fence = NULL;
 115                 drm_syncobj_add_callback_locked(syncobj, cb, func);
 116                 ret = 0;
 117         }
 118         spin_unlock(&syncobj->lock);
 119
 120         return ret;
 121 }
 122
 123 /**
 124  * drm_syncobj_add_callback - adds a callback to syncobj::cb_list
 125  * @syncobj: Sync object to which to add the callback
 126  * @cb: Callback to add
 127  * @func: Func to use when initializing the drm_syncobj_cb struct
 128  *
 129  * This adds a callback to be called next time the fence is replaced
 130  */
 131 void drm_syncobj_add_callback(struct drm_syncobj *syncobj,
 132                               struct drm_syncobj_cb *cb,
 133                               drm_syncobj_func_t func)
 134 {
 135         spin_lock(&syncobj->lock);
 136         drm_syncobj_add_callback_locked(syncobj, cb, func);
 137         spin_unlock(&syncobj->lock);
 138 }
 139 EXPORT_SYMBOL(drm_syncobj_add_callback);
 140
 141 /**
 142  * drm_syncobj_add_callback - removes a callback to syncobj::cb_list
 143  * @syncobj: Sync object from which to remove the callback
 144  * @cb: Callback to remove
 145  */
 146 void drm_syncobj_remove_callback(struct drm_syncobj *syncobj,
 147                                  struct drm_syncobj_cb *cb)
 148 {
 149         spin_lock(&syncobj->lock);
 150         list_del_init(&cb->node);
 151         spin_unlock(&syncobj->lock);
 152 }
 153 EXPORT_SYMBOL(drm_syncobj_remove_callback);
 154
 155 /**
 156  * drm_syncobj_replace_fence - replace fence in a sync object.
 157  * @syncobj: Sync object to replace fence in
 158  * @fence: fence to install in sync file.
 159  *
 160  * This replaces the fence on a sync object.
 161  */
 162 void drm_syncobj_replace_fence(struct drm_syncobj *syncobj,
 163                                struct dma_fence *fence)
 164 {
 165         struct dma_fence *old_fence;
 166         struct drm_syncobj_cb *cur, *tmp;
 167
 168         if (fence)
 169                 dma_fence_get(fence);
 170
 171         spin_lock(&syncobj->lock);
 172
 173         old_fence = rcu_dereference_protected(syncobj->fence,
 174                                               lockdep_is_held(&syncobj->lock));
 175         rcu_assign_pointer(syncobj->fence, fence);
 176
 177         if (fence != old_fence) {
 178                 list_for_each_entry_safe(cur, tmp, &syncobj->cb_list, node) {
 179                         list_del_init(&cur->node);
 180                         cur->func(syncobj, cur);
 181                 }
 182         }
 183
 184         spin_unlock(&syncobj->lock);
 185
 186         dma_fence_put(old_fence);
 187 }
 188 EXPORT_SYMBOL(drm_syncobj_replace_fence);
 189
 190 struct drm_syncobj_null_fence {
 191         struct dma_fence base;
 192         spinlock_t lock;
 193 };
 194
 195 static const char *drm_syncobj_null_fence_get_name(struct dma_fence *fence)
 196 {
 197         return "syncobjnull";
 198 }
 199
 200 static bool drm_syncobj_null_fence_enable_signaling(struct dma_fence *fence)
 201 {
 202     dma_fence_enable_sw_signaling(fence);
 203     return !dma_fence_is_signaled(fence);
 204 }
 205
 206 static const struct dma_fence_ops drm_syncobj_null_fence_ops = {
 207         .get_driver_name = drm_syncobj_null_fence_get_name,
 208         .get_timeline_name = drm_syncobj_null_fence_get_name,
 209         .enable_signaling = drm_syncobj_null_fence_enable_signaling,
 210         .release = NULL,
 211 };
 212
 213 static int drm_syncobj_assign_null_handle(struct drm_syncobj *syncobj)
 214 {
 215         struct drm_syncobj_null_fence *fence;
 216         fence = kzalloc(sizeof(*fence), GFP_KERNEL);
 217         if (fence == NULL)
 218                 return -ENOMEM;
 219
 220         spin_lock_init(&fence->lock);
 221         dma_fence_init(&fence->base, &drm_syncobj_null_fence_ops,
 222                        &fence->lock, 0, 0);
 223         dma_fence_signal(&fence->base);
 224
 225         drm_syncobj_replace_fence(syncobj, &fence->base);
 226
 227         dma_fence_put(&fence->base);
 228
 229         return 0;
 230 }
 231
 232 /**
 233  * drm_syncobj_find_fence - lookup and reference the fence in a sync object
 234  * @file_private: drm file private pointer
 235  * @handle: sync object handle to lookup.
 236  * @fence: out parameter for the fence
 237  *
 238  * This is just a convenience function that combines drm_syncobj_find() and
 239  * drm_syncobj_fence_get().
 240  *
 241  * Returns 0 on success or a negative error value on failure. On success @fence
 242  * contains a reference to the fence, which must be released by calling
 243  * dma_fence_put().
 244  */
 245 int drm_syncobj_find_fence(struct drm_file *file_private,
 246                            u32 handle,
 247                            struct dma_fence **fence)
 248 {
 249         struct drm_syncobj *syncobj = drm_syncobj_find(file_private, handle);
 250         int ret = 0;
 251
 252         if (!syncobj)
 253                 return -ENOENT;
 254
 255         *fence = drm_syncobj_fence_get(syncobj);
 256         if (!*fence) {
 257                 ret = -EINVAL;
 258         }
 259         drm_syncobj_put(syncobj);
 260         return ret;
 261 }
 262 EXPORT_SYMBOL(drm_syncobj_find_fence);
 263
 264 /**
 265  * drm_syncobj_free - free a sync object.
 266  * @kref: kref to free.
 267  *
 268  * Only to be called from kref_put in drm_syncobj_put.
 269  */
 270 void drm_syncobj_free(struct kref *kref)
 271 {
 272         struct drm_syncobj *syncobj = container_of(kref,
 273                                                    struct drm_syncobj,
 274                                                    refcount);
 275         drm_syncobj_replace_fence(syncobj, NULL);
 276         kfree(syncobj);
 277 }
 278 EXPORT_SYMBOL(drm_syncobj_free);
 279
 280 /**
 281  * drm_syncobj_create - create a new syncobj
 282  * @out_syncobj: returned syncobj
 283  * @flags: DRM_SYNCOBJ_* flags
 284  * @fence: if non-NULL, the syncobj will represent this fence
 285  *
 286  * This is the first function to create a sync object. After creating, drivers
 287  * probably want to make it available to userspace, either through
 288  * drm_syncobj_get_handle() or drm_syncobj_get_fd().
 289  *
 290  * Returns 0 on success or a negative error value on failure.
 291  */
 292 int drm_syncobj_create(struct drm_syncobj **out_syncobj, uint32_t flags,
 293                        struct dma_fence *fence)
 294 {
 295         int ret;
 296         struct drm_syncobj *syncobj;
 297
 298         syncobj = kzalloc(sizeof(struct drm_syncobj), GFP_KERNEL);
 299         if (!syncobj)
 300                 return -ENOMEM;
 301
 302         kref_init(&syncobj->refcount);
 303         INIT_LIST_HEAD(&syncobj->cb_list);
 304         spin_lock_init(&syncobj->lock);
 305
 306         if (flags & DRM_SYNCOBJ_CREATE_SIGNALED) {
 307                 ret = drm_syncobj_assign_null_handle(syncobj);
 308                 if (ret < 0) {
 309                         drm_syncobj_put(syncobj);
 310                         return ret;
 311                 }
 312         }
 313
 314         if (fence)
 315                 drm_syncobj_replace_fence(syncobj, fence);
 316
 317         *out_syncobj = syncobj;
 318         return 0;
 319 }
 320 EXPORT_SYMBOL(drm_syncobj_create);
 321
 322 /**
 323  * drm_syncobj_get_handle - get a handle from a syncobj
 324  * @file_private: drm file private pointer
 325  * @syncobj: Sync object to export
 326  * @handle: out parameter with the new handle
 327  *
 328  * Exports a sync object created with drm_syncobj_create() as a handle on
 329  * @file_private to userspace.
 330  *
 331  * Returns 0 on success or a negative error value on failure.
 332  */
 333 int drm_syncobj_get_handle(struct drm_file *file_private,
 334                            struct drm_syncobj *syncobj, u32 *handle)
 335 {
 336         int ret;
 337
 338         /* take a reference to put in the idr */
 339         drm_syncobj_get(syncobj);
 340
 341         idr_preload(GFP_KERNEL);
 342         spin_lock(&file_private->syncobj_table_lock);
 343         ret = idr_alloc(&file_private->syncobj_idr, syncobj, 1, 0, GFP_NOWAIT);
 344         spin_unlock(&file_private->syncobj_table_lock);
 345
 346         idr_preload_end();
 347
 348         if (ret < 0) {
 349                 drm_syncobj_put(syncobj);
 350                 return ret;
 351         }
 352
 353         *handle = ret;
 354         return 0;
 355 }
 356 EXPORT_SYMBOL(drm_syncobj_get_handle);
 357
 358 static int drm_syncobj_create_as_handle(struct drm_file *file_private,
 359                                         u32 *handle, uint32_t flags)
 360 {
 361         int ret;
 362         struct drm_syncobj *syncobj;
 363
 364         ret = drm_syncobj_create(&syncobj, flags, NULL);
 365         if (ret)
 366                 return ret;
 367
 368         ret = drm_syncobj_get_handle(file_private, syncobj, handle);
 369         drm_syncobj_put(syncobj);
 370         return ret;
 371 }
 372
 373 static int drm_syncobj_destroy(struct drm_file *file_private,
 374                                u32 handle)
 375 {
 376         struct drm_syncobj *syncobj;
 377
 378         spin_lock(&file_private->syncobj_table_lock);
 379         syncobj = idr_remove(&file_private->syncobj_idr, handle);
 380         spin_unlock(&file_private->syncobj_table_lock);
 381
 382         if (!syncobj)
 383                 return -EINVAL;
 384
 385         drm_syncobj_put(syncobj);
 386         return 0;
 387 }
 388
 389 static int drm_syncobj_file_release(struct inode *inode, struct file *file)
 390 {
 391         struct drm_syncobj *syncobj = file->private_data;
 392
 393         drm_syncobj_put(syncobj);
 394         return 0;
 395 }
 396
 397 static const struct file_operations drm_syncobj_file_fops = {
 398         .release = drm_syncobj_file_release,
 399 };
 400
 401 /**
 402  * drm_syncobj_get_fd - get a file descriptor from a syncobj
 403  * @syncobj: Sync object to export
 404  * @p_fd: out parameter with the new file descriptor
 405  *
 406  * Exports a sync object created with drm_syncobj_create() as a file descriptor.
 407  *
 408  * Returns 0 on success or a negative error value on failure.
 409  */
 410 int drm_syncobj_get_fd(struct drm_syncobj *syncobj, int *p_fd)
 411 {
 412         struct file *file;
 413         int fd;
 414
 415         fd = get_unused_fd_flags(O_CLOEXEC);
 416         if (fd < 0)
 417                 return fd;
 418
 419         file = anon_inode_getfile("syncobj_file",
 420                                   &drm_syncobj_file_fops,
 421                                   syncobj, 0);
 422         if (IS_ERR(file)) {
 423                 put_unused_fd(fd);
 424                 return PTR_ERR(file);
 425         }
 426
 427         drm_syncobj_get(syncobj);
 428         fd_install(fd, file);
 429
 430         *p_fd = fd;
 431         return 0;
 432 }
 433 EXPORT_SYMBOL(drm_syncobj_get_fd);
 434
 435 static int drm_syncobj_handle_to_fd(struct drm_file *file_private,
 436                                     u32 handle, int *p_fd)
 437 {
 438         struct drm_syncobj *syncobj = drm_syncobj_find(file_private, handle);
 439         int ret;
 440
 441         if (!syncobj)
 442                 return -EINVAL;
 443
 444         ret = drm_syncobj_get_fd(syncobj, p_fd);
 445         drm_syncobj_put(syncobj);
 446         return ret;
 447 }
 448
 449 static int drm_syncobj_fd_to_handle(struct drm_file *file_private,
 450                                     int fd, u32 *handle)
 451 {
 452         struct drm_syncobj *syncobj;
 453         struct file *file;
 454         int ret;
 455
 456         file = fget(fd);
 457         if (!file)
 458                 return -EINVAL;
 459
 460         if (file->f_op != &drm_syncobj_file_fops) {
 461                 fput(file);
 462                 return -EINVAL;
 463         }
 464
 465         /* take a reference to put in the idr */
 466         syncobj = file->private_data;
 467         drm_syncobj_get(syncobj);
 468
 469         idr_preload(GFP_KERNEL);
 470         spin_lock(&file_private->syncobj_table_lock);
 471         ret = idr_alloc(&file_private->syncobj_idr, syncobj, 1, 0, GFP_NOWAIT);
 472         spin_unlock(&file_private->syncobj_table_lock);
 473         idr_preload_end();
 474
 475         if (ret > 0) {
 476                 *handle = ret;
 477                 ret = 0;
 478         } else
 479                 drm_syncobj_put(syncobj);
 480
 481         fput(file);
 482         return ret;
 483 }
 484
 485 static int drm_syncobj_import_sync_file_fence(struct drm_file *file_private,
 486                                               int fd, int handle)
 487 {
 488         struct dma_fence *fence = sync_file_get_fence(fd);
 489         struct drm_syncobj *syncobj;
 490
 491         if (!fence)
 492                 return -EINVAL;
 493
 494         syncobj = drm_syncobj_find(file_private, handle);
 495         if (!syncobj) {
 496                 dma_fence_put(fence);
 497                 return -ENOENT;
 498         }
 499
 500         drm_syncobj_replace_fence(syncobj, fence);
 501         dma_fence_put(fence);
 502         drm_syncobj_put(syncobj);
 503         return 0;
 504 }
 505
 506 static int drm_syncobj_export_sync_file(struct drm_file *file_private,
 507                                         int handle, int *p_fd)
 508 {
 509         int ret;
 510         struct dma_fence *fence;
 511         struct sync_file *sync_file;
 512         int fd = get_unused_fd_flags(O_CLOEXEC);
 513
 514         if (fd < 0)
 515                 return fd;
 516
 517         ret = drm_syncobj_find_fence(file_private, handle, &fence);
 518         if (ret)
 519                 goto err_put_fd;
 520
 521         sync_file = sync_file_create(fence);
 522
 523         dma_fence_put(fence);
 524
 525         if (!sync_file) {
 526                 ret = -EINVAL;
 527                 goto err_put_fd;
 528         }
 529
 530         fd_install(fd, sync_file->file);
 531
 532         *p_fd = fd;
 533         return 0;
 534 err_put_fd:
 535         put_unused_fd(fd);
 536         return ret;
 537 }
 538 /**
 539  * drm_syncobj_open - initalizes syncobj file-private structures at devnode open time
 540  * @file_private: drm file-private structure to set up
 541  *
 542  * Called at device open time, sets up the structure for handling refcounting
 543  * of sync objects.
 544  */
 545 void
 546 drm_syncobj_open(struct drm_file *file_private)
 547 {
 548         idr_init_base(&file_private->syncobj_idr, 1);
 549         spin_lock_init(&file_private->syncobj_table_lock);
 550 }
 551
 552 static int
 553 drm_syncobj_release_handle(int id, void *ptr, void *data)
 554 {
 555         struct drm_syncobj *syncobj = ptr;
 556
 557         drm_syncobj_put(syncobj);
 558         return 0;
 559 }
 560
 561 /**
 562  * drm_syncobj_release - release file-private sync object resources
 563  * @file_private: drm file-private structure to clean up
 564  *
 565  * Called at close time when the filp is going away.
 566  *
 567  * Releases any remaining references on objects by this filp.
 568  */
 569 void
 570 drm_syncobj_release(struct drm_file *file_private)
 571 {
 572         idr_for_each(&file_private->syncobj_idr,
 573                      &drm_syncobj_release_handle, file_private);
 574         idr_destroy(&file_private->syncobj_idr);
 575 }
 576
 577 int
 578 drm_syncobj_create_ioctl(struct drm_device *dev, void *data,
 579                          struct drm_file *file_private)
 580 {
 581         struct drm_syncobj_create *args = data;
 582
 583         if (!drm_core_check_feature(dev, DRIVER_SYNCOBJ))
 584                 return -ENODEV;
 585
 586         /* no valid flags yet */
 587         if (args->flags & ~DRM_SYNCOBJ_CREATE_SIGNALED)
 588                 return -EINVAL;
 589
 590         return drm_syncobj_create_as_handle(file_private,
 591                                             &args->handle, args->flags);
 592 }
 593
 594 int
 595 drm_syncobj_destroy_ioctl(struct drm_device *dev, void *data,
 596                           struct drm_file *file_private)
 597 {
 598         struct drm_syncobj_destroy *args = data;
 599
 600         if (!drm_core_check_feature(dev, DRIVER_SYNCOBJ))
 601                 return -ENODEV;
 602
 603         /* make sure padding is empty */
 604         if (args->pad)
 605                 return -EINVAL;
 606         return drm_syncobj_destroy(file_private, args->handle);
 607 }
 608
 609 int
 610 drm_syncobj_handle_to_fd_ioctl(struct drm_device *dev, void *data,
 611                                    struct drm_file *file_private)
 612 {
 613         struct drm_syncobj_handle *args = data;
 614
 615         if (!drm_core_check_feature(dev, DRIVER_SYNCOBJ))
 616                 return -ENODEV;
 617
 618         if (args->pad)
 619                 return -EINVAL;
 620
 621         if (args->flags != 0 &&
 622             args->flags != DRM_SYNCOBJ_HANDLE_TO_FD_FLAGS_EXPORT_SYNC_FILE)
 623                 return -EINVAL;
 624
 625         if (args->flags & DRM_SYNCOBJ_HANDLE_TO_FD_FLAGS_EXPORT_SYNC_FILE)
 626                 return drm_syncobj_export_sync_file(file_private, args->handle,
 627                                                     &args->fd);
 628
 629         return drm_syncobj_handle_to_fd(file_private, args->handle,
 630                                         &args->fd);
 631 }
 632
 633 int
 634 drm_syncobj_fd_to_handle_ioctl(struct drm_device *dev, void *data,
 635                                    struct drm_file *file_private)
 636 {
 637         struct drm_syncobj_handle *args = data;
 638
 639         if (!drm_core_check_feature(dev, DRIVER_SYNCOBJ))
 640                 return -ENODEV;
 641
 642         if (args->pad)
 643                 return -EINVAL;
 644
 645         if (args->flags != 0 &&
 646             args->flags != DRM_SYNCOBJ_FD_TO_HANDLE_FLAGS_IMPORT_SYNC_FILE)
 647                 return -EINVAL;
 648
 649         if (args->flags & DRM_SYNCOBJ_FD_TO_HANDLE_FLAGS_IMPORT_SYNC_FILE)
 650                 return drm_syncobj_import_sync_file_fence(file_private,
 651                                                           args->fd,
 652                                                           args->handle);
 653
 654         return drm_syncobj_fd_to_handle(file_private, args->fd,
 655                                         &args->handle);
 656 }
 657
 658 struct syncobj_wait_entry {
 659         struct task_struct *task;
 660         struct dma_fence *fence;
 661         struct dma_fence_cb fence_cb;
 662         struct drm_syncobj_cb syncobj_cb;
 663 };
 664
 665 static void syncobj_wait_fence_func(struct dma_fence *fence,
 666                                     struct dma_fence_cb *cb)
 667 {
 668         struct syncobj_wait_entry *wait =
 669                 container_of(cb, struct syncobj_wait_entry, fence_cb);
 670
 671         wake_up_process(wait->task);
 672 }
 673
 674 static void syncobj_wait_syncobj_func(struct drm_syncobj *syncobj,
 675                                       struct drm_syncobj_cb *cb)
 676 {
 677         struct syncobj_wait_entry *wait =
 678                 container_of(cb, struct syncobj_wait_entry, syncobj_cb);
 679
 680         /* This happens inside the syncobj lock */
 681         wait->fence = dma_fence_get(rcu_dereference_protected(syncobj->fence,
 682                                                               lockdep_is_held(&syncobj->lock)));
 683         wake_up_process(wait->task);
 684 }
 685
 686 static signed long drm_syncobj_array_wait_timeout(struct drm_syncobj **syncobjs,
 687                                                   uint32_t count,
 688                                                   uint32_t flags,
 689                                                   signed long timeout,
 690                                                   uint32_t *idx)
 691 {
 692         struct syncobj_wait_entry *entries;
 693         struct dma_fence *fence;
 694         signed long ret;
 695         uint32_t signaled_count, i;
 696
 697         entries = kcalloc(count, sizeof(*entries), GFP_KERNEL);
 698         if (!entries)
 699                 return -ENOMEM;
 700
 701         /* Walk the list of sync objects and initialize entries.  We do
 702          * this up-front so that we can properly return -EINVAL if there is
 703          * a syncobj with a missing fence and then never have the chance of
 704          * returning -EINVAL again.
 705          */
 706         signaled_count = 0;
 707         for (i = 0; i < count; ++i) {
 708                 entries[i].task = current;
 709                 entries[i].fence = drm_syncobj_fence_get(syncobjs[i]);
 710                 if (!entries[i].fence) {
 711                         if (flags & DRM_SYNCOBJ_WAIT_FLAGS_WAIT_FOR_SUBMIT) {
 712                                 continue;
 713                         } else {
 714                                 ret = -EINVAL;
 715                                 goto cleanup_entries;
 716                         }
 717                 }
 718
 719                 if (dma_fence_is_signaled(entries[i].fence)) {
 720                         if (signaled_count == 0 && idx)
 721                                 *idx = i;
 722                         signaled_count++;
 723                 }
 724         }
 725
 726         /* Initialize ret to the max of timeout and 1.  That way, the
 727          * default return value indicates a successful wait and not a
 728          * timeout.
 729          */
 730         ret = max_t(signed long, timeout, 1);
 731
 732         if (signaled_count == count ||
 733             (signaled_count > 0 &&
 734              !(flags & DRM_SYNCOBJ_WAIT_FLAGS_WAIT_ALL)))
 735                 goto cleanup_entries;
 736
 737         /* There's a very annoying laxness in the dma_fence API here, in
 738          * that backends are not required to automatically report when a
 739          * fence is signaled prior to fence->ops->enable_signaling() being
 740          * called.  So here if we fail to match signaled_count, we need to
 741          * fallthough and try a 0 timeout wait!
 742          */
 743
 744         if (flags & DRM_SYNCOBJ_WAIT_FLAGS_WAIT_FOR_SUBMIT) {
 745                 for (i = 0; i < count; ++i) {
 746                         drm_syncobj_fence_get_or_add_callback(syncobjs[i],
 747                                                               &entries[i].fence,
 748                                                               &entries[i].syncobj_cb,
 749                                                               syncobj_wait_syncobj_func);
 750                 }
 751         }
 752
 753         do {
 754                 set_current_state(TASK_INTERRUPTIBLE);
 755
 756                 signaled_count = 0;
 757                 for (i = 0; i < count; ++i) {
 758                         fence = entries[i].fence;
 759                         if (!fence)
 760                                 continue;
 761
 762                         if (dma_fence_is_signaled(fence) ||
 763                             (!entries[i].fence_cb.func &&
 764                              dma_fence_add_callback(fence,
 765                                                     &entries[i].fence_cb,
 766                                                     syncobj_wait_fence_func))) {
 767                                 /* The fence has been signaled */
 768                                 if (flags & DRM_SYNCOBJ_WAIT_FLAGS_WAIT_ALL) {
 769                                         signaled_count++;
 770                                 } else {
 771                                         if (idx)
 772                                                 *idx = i;
 773                                         goto done_waiting;
 774                                 }
 775                         }
 776                 }
 777
 778                 if (signaled_count == count)
 779                         goto done_waiting;
 780
 781                 if (timeout == 0) {
 782                         /* If we are doing a 0 timeout wait and we got
 783                          * here, then we just timed out.
 784                          */
 785                         ret = 0;
 786                         goto done_waiting;
 787                 }
 788
 789                 ret = schedule_timeout(ret);
 790
 791                 if (ret > 0 && signal_pending(current))
 792                         ret = -ERESTARTSYS;
 793         } while (ret > 0);
 794
 795 done_waiting:
 796         __set_current_state(TASK_RUNNING);
 797
 798 cleanup_entries:
 799         for (i = 0; i < count; ++i) {
 800                 if (entries[i].syncobj_cb.func)
 801                         drm_syncobj_remove_callback(syncobjs[i],
 802                                                     &entries[i].syncobj_cb);
 803                 if (entries[i].fence_cb.func)
 804                         dma_fence_remove_callback(entries[i].fence,
 805                                                   &entries[i].fence_cb);
 806                 dma_fence_put(entries[i].fence);
 807         }
 808         kfree(entries);
 809
 810         return ret;
 811 }
 812
 813 /**
 814  * drm_timeout_abs_to_jiffies - calculate jiffies timeout from absolute value
 815  *
 816  * @timeout_nsec: timeout nsec component in ns, 0 for poll
 817  *
 818  * Calculate the timeout in jiffies from an absolute time in sec/nsec.
 819  */
 820 static signed long drm_timeout_abs_to_jiffies(int64_t timeout_nsec)
 821 {
 822         ktime_t abs_timeout, now;
 823         u64 timeout_ns, timeout_jiffies64;
 824
 825         /* make 0 timeout means poll - absolute 0 doesn't seem valid */
 826         if (timeout_nsec == 0)
 827                 return 0;
 828
 829         abs_timeout = ns_to_ktime(timeout_nsec);
 830         now = ktime_get();
 831
 832         if (!ktime_after(abs_timeout, now))
 833                 return 0;
 834
 835         timeout_ns = ktime_to_ns(ktime_sub(abs_timeout, now));
 836
 837         timeout_jiffies64 = nsecs_to_jiffies64(timeout_ns);
 838         /*  clamp timeout to avoid infinite timeout */
 839         if (timeout_jiffies64 >= MAX_SCHEDULE_TIMEOUT - 1)
 840                 return MAX_SCHEDULE_TIMEOUT - 1;
 841
 842         return timeout_jiffies64 + 1;
 843 }
 844
 845 static int drm_syncobj_array_wait(struct drm_device *dev,
 846                                   struct drm_file *file_private,
 847                                   struct drm_syncobj_wait *wait,
 848                                   struct drm_syncobj **syncobjs)
 849 {
 850         signed long timeout = drm_timeout_abs_to_jiffies(wait->timeout_nsec);
 851         signed long ret = 0;
 852         uint32_t first = ~0;
 853
 854         ret = drm_syncobj_array_wait_timeout(syncobjs,
 855                                              wait->count_handles,
 856                                              wait->flags,
 857                                              timeout, &first);
 858         if (ret < 0)
 859                 return ret;
 860
 861         wait->first_signaled = first;
 862         if (ret == 0)
 863                 return -ETIME;
 864         return 0;
 865 }
 866
 867 static int drm_syncobj_array_find(struct drm_file *file_private,
 868                                   void __user *user_handles,
 869                                   uint32_t count_handles,
 870                                   struct drm_syncobj ***syncobjs_out)
 871 {
 872         uint32_t i, *handles;
 873         struct drm_syncobj **syncobjs;
 874         int ret;
 875
 876         handles = kmalloc_array(count_handles, sizeof(*handles), GFP_KERNEL);
 877         if (handles == NULL)
 878                 return -ENOMEM;
 879
 880         if (copy_from_user(handles, user_handles,
 881                            sizeof(uint32_t) * count_handles)) {
 882                 ret = -EFAULT;
 883                 goto err_free_handles;
 884         }
 885
 886         syncobjs = kmalloc_array(count_handles, sizeof(*syncobjs), GFP_KERNEL);
 887         if (syncobjs == NULL) {
 888                 ret = -ENOMEM;
 889                 goto err_free_handles;
 890         }
 891
 892         for (i = 0; i < count_handles; i++) {
 893                 syncobjs[i] = drm_syncobj_find(file_private, handles[i]);
 894                 if (!syncobjs[i]) {
 895                         ret = -ENOENT;
 896                         goto err_put_syncobjs;
 897                 }
 898         }
 899
 900         kfree(handles);
 901         *syncobjs_out = syncobjs;
 902         return 0;
 903
 904 err_put_syncobjs:
 905         while (i-- > 0)
 906                 drm_syncobj_put(syncobjs[i]);
 907         kfree(syncobjs);
 908 err_free_handles:
 909         kfree(handles);
 910
 911         return ret;
 912 }
 913
 914 static void drm_syncobj_array_free(struct drm_syncobj **syncobjs,
 915                                    uint32_t count)
 916 {
 917         uint32_t i;
 918         for (i = 0; i < count; i++)
 919                 drm_syncobj_put(syncobjs[i]);
 920         kfree(syncobjs);
 921 }
 922
 923 int
 924 drm_syncobj_wait_ioctl(struct drm_device *dev, void *data,
 925                        struct drm_file *file_private)
 926 {
 927         struct drm_syncobj_wait *args = data;
 928         struct drm_syncobj **syncobjs;
 929         int ret = 0;
 930
 931         if (!drm_core_check_feature(dev, DRIVER_SYNCOBJ))
 932                 return -ENODEV;
 933
 934         if (args->flags & ~(DRM_SYNCOBJ_WAIT_FLAGS_WAIT_ALL |
 935                             DRM_SYNCOBJ_WAIT_FLAGS_WAIT_FOR_SUBMIT))
 936                 return -EINVAL;
 937
 938         if (args->count_handles == 0)
 939                 return -EINVAL;
 940
 941         ret = drm_syncobj_array_find(file_private,
 942                                      u64_to_user_ptr(args->handles),
 943                                      args->count_handles,
 944                                      &syncobjs);
 945         if (ret < 0)
 946                 return ret;
 947
 948         ret = drm_syncobj_array_wait(dev, file_private,
 949                                      args, syncobjs);
 950
 951         drm_syncobj_array_free(syncobjs, args->count_handles);
 952
 953         return ret;
 954 }
 955
 956 int
 957 drm_syncobj_reset_ioctl(struct drm_device *dev, void *data,
 958                         struct drm_file *file_private)
 959 {
 960         struct drm_syncobj_array *args = data;
 961         struct drm_syncobj **syncobjs;
 962         uint32_t i;
 963         int ret;
 964
 965         if (!drm_core_check_feature(dev, DRIVER_SYNCOBJ))
 966                 return -ENODEV;
 967
 968         if (args->pad != 0)
 969                 return -EINVAL;
 970
 971         if (args->count_handles == 0)
 972                 return -EINVAL;
 973
 974         ret = drm_syncobj_array_find(file_private,
 975                                      u64_to_user_ptr(args->handles),
 976                                      args->count_handles,
 977                                      &syncobjs);
 978         if (ret < 0)
 979                 return ret;
 980
 981         for (i = 0; i < args->count_handles; i++)
 982                 drm_syncobj_replace_fence(syncobjs[i], NULL);
 983
 984         drm_syncobj_array_free(syncobjs, args->count_handles);
 985
 986         return 0;
 987 }
 988
 989 int
 990 drm_syncobj_signal_ioctl(struct drm_device *dev, void *data,
 991                          struct drm_file *file_private)
 992 {
 993         struct drm_syncobj_array *args = data;
 994         struct drm_syncobj **syncobjs;
 995         uint32_t i;
 996         int ret;
 997
 998         if (!drm_core_check_feature(dev, DRIVER_SYNCOBJ))
 999                 return -ENODEV;
1000
1001         if (args->pad != 0)
1002                 return -EINVAL;
1003
1004         if (args->count_handles == 0)
1005                 return -EINVAL;
1006
1007         ret = drm_syncobj_array_find(file_private,
1008                                      u64_to_user_ptr(args->handles),
1009                                      args->count_handles,
1010                                      &syncobjs);
1011         if (ret < 0)
1012                 return ret;
1013
1014         for (i = 0; i < args->count_handles; i++) {
1015                 ret = drm_syncobj_assign_null_handle(syncobjs[i]);
1016                 if (ret < 0)
1017                         break;
1018         }
1019
1020         drm_syncobj_array_free(syncobjs, args->count_handles);
1021
1022         return ret;
1023 }