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) provide a
  33  * container for a synchronization primitive which can be used by userspace
  34  * to explicitly synchronize GPU commands, can be shared between userspace
  35  * processes, and can be shared between different DRM drivers.
  36  * Their primary use-case is to implement Vulkan fences and semaphores.
  37  * The syncobj userspace API provides ioctls for several operations:
  38  *
  39  *  - Creation and destruction of syncobjs
  40  *  - Import and export of syncobjs to/from a syncobj file descriptor
  41  *  - Import and export a syncobj's underlying fence to/from a sync file
  42  *  - Reset a syncobj (set its fence to NULL)
  43  *  - Signal a syncobj (set a trivially signaled fence)
  44  *  - Wait for a syncobj's fence to appear and be signaled
  45  *
  46  * The syncobj userspace API also provides operations to manipulate a syncobj
  47  * in terms of a timeline of struct &dma_fence_chain rather than a single
  48  * struct &dma_fence, through the following operations:
  49  *
  50  *   - Signal a given point on the timeline
  51  *   - Wait for a given point to appear and/or be signaled
  52  *   - Import and export from/to a given point of a timeline
  53  *
  54  * At it's core, a syncobj is simply a wrapper around a pointer to a struct
  55  * &dma_fence which may be NULL.
  56  * When a syncobj is first created, its pointer is either NULL or a pointer
  57  * to an already signaled fence depending on whether the
  58  * &DRM_SYNCOBJ_CREATE_SIGNALED flag is passed to
  59  * &DRM_IOCTL_SYNCOBJ_CREATE.
  60  *
  61  * If the syncobj is considered as a binary (its state is either signaled or
  62  * unsignaled) primitive, when GPU work is enqueued in a DRM driver to signal
  63  * the syncobj, the syncobj's fence is replaced with a fence which will be
  64  * signaled by the completion of that work.
  65  * If the syncobj is considered as a timeline primitive, when GPU work is
  66  * enqueued in a DRM driver to signal the a given point of the syncobj, a new
  67  * struct &dma_fence_chain pointing to the DRM driver's fence and also
  68  * pointing to the previous fence that was in the syncobj. The new struct
  69  * &dma_fence_chain fence replace the syncobj's fence and will be signaled by
  70  * completion of the DRM driver's work and also any work associated with the
  71  * fence previously in the syncobj.
  72  *
  73  * When GPU work which waits on a syncobj is enqueued in a DRM driver, at the
  74  * time the work is enqueued, it waits on the syncobj's fence before
  75  * submitting the work to hardware. That fence is either :
  76  *
  77  *    - The syncobj's current fence if the syncobj is considered as a binary
  78  *      primitive.
  79  *    - The struct &dma_fence associated with a given point if the syncobj is
  80  *      considered as a timeline primitive.
  81  *
  82  * If the syncobj's fence is NULL or not present in the syncobj's timeline,
  83  * the enqueue operation is expected to fail.
  84  *
  85  * With binary syncobj, all manipulation of the syncobjs's fence happens in
  86  * terms of the current fence at the time the ioctl is called by userspace
  87  * regardless of whether that operation is an immediate host-side operation
  88  * (signal or reset) or or an operation which is enqueued in some driver
  89  * queue. &DRM_IOCTL_SYNCOBJ_RESET and &DRM_IOCTL_SYNCOBJ_SIGNAL can be used
  90  * to manipulate a syncobj from the host by resetting its pointer to NULL or
  91  * setting its pointer to a fence which is already signaled.
  92  *
  93  * With a timeline syncobj, all manipulation of the synobj's fence happens in
  94  * terms of a u64 value referring to point in the timeline. See
  95  * dma_fence_chain_find_seqno() to see how a given point is found in the
  96  * timeline.
  97  *
  98  * Note that applications should be careful to always use timeline set of
  99  * ioctl() when dealing with syncobj considered as timeline. Using a binary
 100  * set of ioctl() with a syncobj considered as timeline could result incorrect
 101  * synchronization. The use of binary syncobj is supported through the
 102  * timeline set of ioctl() by using a point value of 0, this will reproduce
 103  * the behavior of the binary set of ioctl() (for example replace the
 104  * syncobj's fence when signaling).
 105  *
 106  *
 107  * Host-side wait on syncobjs
 108  * --------------------------
 109  *
 110  * &DRM_IOCTL_SYNCOBJ_WAIT takes an array of syncobj handles and does a
 111  * host-side wait on all of the syncobj fences simultaneously.
 112  * If &DRM_SYNCOBJ_WAIT_FLAGS_WAIT_ALL is set, the wait ioctl will wait on
 113  * all of the syncobj fences to be signaled before it returns.
 114  * Otherwise, it returns once at least one syncobj fence has been signaled
 115  * and the index of a signaled fence is written back to the client.
 116  *
 117  * Unlike the enqueued GPU work dependencies which fail if they see a NULL
 118  * fence in a syncobj, if &DRM_SYNCOBJ_WAIT_FLAGS_WAIT_FOR_SUBMIT is set,
 119  * the host-side wait will first wait for the syncobj to receive a non-NULL
 120  * fence and then wait on that fence.
 121  * If &DRM_SYNCOBJ_WAIT_FLAGS_WAIT_FOR_SUBMIT is not set and any one of the
 122  * syncobjs in the array has a NULL fence, -EINVAL will be returned.
 123  * Assuming the syncobj starts off with a NULL fence, this allows a client
 124  * to do a host wait in one thread (or process) which waits on GPU work
 125  * submitted in another thread (or process) without having to manually
 126  * synchronize between the two.
 127  * This requirement is inherited from the Vulkan fence API.
 128  *
 129  * If &DRM_SYNCOBJ_WAIT_FLAGS_WAIT_DEADLINE is set, the ioctl will also set
 130  * a fence deadline hint on the backing fences before waiting, to provide the
 131  * fence signaler with an appropriate sense of urgency.  The deadline is
 132  * specified as an absolute &CLOCK_MONOTONIC value in units of ns.
 133  *
 134  * Similarly, &DRM_IOCTL_SYNCOBJ_TIMELINE_WAIT takes an array of syncobj
 135  * handles as well as an array of u64 points and does a host-side wait on all
 136  * of syncobj fences at the given points simultaneously.
 137  *
 138  * &DRM_IOCTL_SYNCOBJ_TIMELINE_WAIT also adds the ability to wait for a given
 139  * fence to materialize on the timeline without waiting for the fence to be
 140  * signaled by using the &DRM_SYNCOBJ_WAIT_FLAGS_WAIT_AVAILABLE flag. This
 141  * requirement is inherited from the wait-before-signal behavior required by
 142  * the Vulkan timeline semaphore API.
 143  *
 144  * Alternatively, &DRM_IOCTL_SYNCOBJ_EVENTFD can be used to wait without
 145  * blocking: an eventfd will be signaled when the syncobj is. This is useful to
 146  * integrate the wait in an event loop.
 147  *
 148  *
 149  * Import/export of syncobjs
 150  * -------------------------
 151  *
 152  * &DRM_IOCTL_SYNCOBJ_FD_TO_HANDLE and &DRM_IOCTL_SYNCOBJ_HANDLE_TO_FD
 153  * provide two mechanisms for import/export of syncobjs.
 154  *
 155  * The first lets the client import or export an entire syncobj to a file
 156  * descriptor.
 157  * These fd's are opaque and have no other use case, except passing the
 158  * syncobj between processes.
 159  * All exported file descriptors and any syncobj handles created as a
 160  * result of importing those file descriptors own a reference to the
 161  * same underlying struct &drm_syncobj and the syncobj can be used
 162  * persistently across all the processes with which it is shared.
 163  * The syncobj is freed only once the last reference is dropped.
 164  * Unlike dma-buf, importing a syncobj creates a new handle (with its own
 165  * reference) for every import instead of de-duplicating.
 166  * The primary use-case of this persistent import/export is for shared
 167  * Vulkan fences and semaphores.
 168  *
 169  * The second import/export mechanism, which is indicated by
 170  * &DRM_SYNCOBJ_FD_TO_HANDLE_FLAGS_IMPORT_SYNC_FILE or
 171  * &DRM_SYNCOBJ_HANDLE_TO_FD_FLAGS_EXPORT_SYNC_FILE lets the client
 172  * import/export the syncobj's current fence from/to a &sync_file.
 173  * When a syncobj is exported to a sync file, that sync file wraps the
 174  * sycnobj's fence at the time of export and any later signal or reset
 175  * operations on the syncobj will not affect the exported sync file.
 176  * When a sync file is imported into a syncobj, the syncobj's fence is set
 177  * to the fence wrapped by that sync file.
 178  * Because sync files are immutable, resetting or signaling the syncobj
 179  * will not affect any sync files whose fences have been imported into the
 180  * syncobj.
 181  *
 182  *
 183  * Import/export of timeline points in timeline syncobjs
 184  * -----------------------------------------------------
 185  *
 186  * &DRM_IOCTL_SYNCOBJ_TRANSFER provides a mechanism to transfer a struct
 187  * &dma_fence_chain of a syncobj at a given u64 point to another u64 point
 188  * into another syncobj.
 189  *
 190  * Note that if you want to transfer a struct &dma_fence_chain from a given
 191  * point on a timeline syncobj from/into a binary syncobj, you can use the
 192  * point 0 to mean take/replace the fence in the syncobj.
 193  */
 194
 195 #include <linux/anon_inodes.h>
 196 #include <linux/dma-fence-unwrap.h>
 197 #include <linux/eventfd.h>
 198 #include <linux/file.h>
 199 #include <linux/fs.h>
 200 #include <linux/sched/signal.h>
 201 #include <linux/sync_file.h>
 202 #include <linux/uaccess.h>
 203
 204 #include <drm/drm.h>
 205 #include <drm/drm_drv.h>
 206 #include <drm/drm_file.h>
 207 #include <drm/drm_gem.h>
 208 #include <drm/drm_print.h>
 209 #include <drm/drm_syncobj.h>
 210 #include <drm/drm_utils.h>
 211
 212 #include "drm_internal.h"
 213
 214 struct syncobj_wait_entry {
 215         struct list_head node;
 216         struct task_struct *task;
 217         struct dma_fence *fence;
 218         struct dma_fence_cb fence_cb;
 219         u64    point;
 220 };
 221
 222 static void syncobj_wait_syncobj_func(struct drm_syncobj *syncobj,
 223                                       struct syncobj_wait_entry *wait);
 224
 225 struct syncobj_eventfd_entry {
 226         struct list_head node;
 227         struct dma_fence *fence;
 228         struct dma_fence_cb fence_cb;
 229         struct drm_syncobj *syncobj;
 230         struct eventfd_ctx *ev_fd_ctx;
 231         u64 point;
 232         u32 flags;
 233 };
 234
 235 static void
 236 syncobj_eventfd_entry_func(struct drm_syncobj *syncobj,
 237                            struct syncobj_eventfd_entry *entry);
 238
 239 /**
 240  * drm_syncobj_find - lookup and reference a sync object.
 241  * @file_private: drm file private pointer
 242  * @handle: sync object handle to lookup.
 243  *
 244  * Returns a reference to the syncobj pointed to by handle or NULL. The
 245  * reference must be released by calling drm_syncobj_put().
 246  */
 247 struct drm_syncobj *drm_syncobj_find(struct drm_file *file_private,
 248                                      u32 handle)
 249 {
 250         struct drm_syncobj *syncobj;
 251
 252         spin_lock(&file_private->syncobj_table_lock);
 253
 254         /* Check if we currently have a reference on the object */
 255         syncobj = idr_find(&file_private->syncobj_idr, handle);
 256         if (syncobj)
 257                 drm_syncobj_get(syncobj);
 258
 259         spin_unlock(&file_private->syncobj_table_lock);
 260
 261         return syncobj;
 262 }
 263 EXPORT_SYMBOL(drm_syncobj_find);
 264
 265 static void drm_syncobj_fence_add_wait(struct drm_syncobj *syncobj,
 266                                        struct syncobj_wait_entry *wait)
 267 {
 268         struct dma_fence *fence;
 269
 270         if (wait->fence)
 271                 return;
 272
 273         spin_lock(&syncobj->lock);
 274         /* We've already tried once to get a fence and failed.  Now that we
 275          * have the lock, try one more time just to be sure we don't add a
 276          * callback when a fence has already been set.
 277          */
 278         fence = dma_fence_get(rcu_dereference_protected(syncobj->fence, 1));
 279         if (!fence || dma_fence_chain_find_seqno(&fence, wait->point)) {
 280                 dma_fence_put(fence);
 281                 list_add_tail(&wait->node, &syncobj->cb_list);
 282         } else if (!fence) {
 283                 wait->fence = dma_fence_get_stub();
 284         } else {
 285                 wait->fence = fence;
 286         }
 287         spin_unlock(&syncobj->lock);
 288 }
 289
 290 static void drm_syncobj_remove_wait(struct drm_syncobj *syncobj,
 291                                     struct syncobj_wait_entry *wait)
 292 {
 293         if (!wait->node.next)
 294                 return;
 295
 296         spin_lock(&syncobj->lock);
 297         list_del_init(&wait->node);
 298         spin_unlock(&syncobj->lock);
 299 }
 300
 301 static void
 302 syncobj_eventfd_entry_free(struct syncobj_eventfd_entry *entry)
 303 {
 304         eventfd_ctx_put(entry->ev_fd_ctx);
 305         dma_fence_put(entry->fence);
 306         /* This happens either inside the syncobj lock, or after the node has
 307          * already been removed from the list.
 308          */
 309         list_del(&entry->node);
 310         kfree(entry);
 311 }
 312
 313 static void
 314 drm_syncobj_add_eventfd(struct drm_syncobj *syncobj,
 315                         struct syncobj_eventfd_entry *entry)
 316 {
 317         spin_lock(&syncobj->lock);
 318         list_add_tail(&entry->node, &syncobj->ev_fd_list);
 319         syncobj_eventfd_entry_func(syncobj, entry);
 320         spin_unlock(&syncobj->lock);
 321 }
 322
 323 /**
 324  * drm_syncobj_add_point - add new timeline point to the syncobj
 325  * @syncobj: sync object to add timeline point do
 326  * @chain: chain node to use to add the point
 327  * @fence: fence to encapsulate in the chain node
 328  * @point: sequence number to use for the point
 329  *
 330  * Add the chain node as new timeline point to the syncobj.
 331  */
 332 void drm_syncobj_add_point(struct drm_syncobj *syncobj,
 333                            struct dma_fence_chain *chain,
 334                            struct dma_fence *fence,
 335                            uint64_t point)
 336 {
 337         struct syncobj_wait_entry *wait_cur, *wait_tmp;
 338         struct syncobj_eventfd_entry *ev_fd_cur, *ev_fd_tmp;
 339         struct dma_fence *prev;
 340
 341         dma_fence_get(fence);
 342
 343         spin_lock(&syncobj->lock);
 344
 345         prev = drm_syncobj_fence_get(syncobj);
 346         /* You are adding an unorder point to timeline, which could cause payload returned from query_ioctl is 0! */
 347         if (prev && prev->seqno >= point)
 348                 DRM_DEBUG("You are adding an unorder point to timeline!\n");
 349         dma_fence_chain_init(chain, prev, fence, point);
 350         rcu_assign_pointer(syncobj->fence, &chain->base);
 351
 352         list_for_each_entry_safe(wait_cur, wait_tmp, &syncobj->cb_list, node)
 353                 syncobj_wait_syncobj_func(syncobj, wait_cur);
 354         list_for_each_entry_safe(ev_fd_cur, ev_fd_tmp, &syncobj->ev_fd_list, node)
 355                 syncobj_eventfd_entry_func(syncobj, ev_fd_cur);
 356         spin_unlock(&syncobj->lock);
 357
 358         /* Walk the chain once to trigger garbage collection */
 359         dma_fence_chain_for_each(fence, prev);
 360         dma_fence_put(prev);
 361 }
 362 EXPORT_SYMBOL(drm_syncobj_add_point);
 363
 364 /**
 365  * drm_syncobj_replace_fence - replace fence in a sync object.
 366  * @syncobj: Sync object to replace fence in
 367  * @fence: fence to install in sync file.
 368  *
 369  * This replaces the fence on a sync object.
 370  */
 371 void drm_syncobj_replace_fence(struct drm_syncobj *syncobj,
 372                                struct dma_fence *fence)
 373 {
 374         struct dma_fence *old_fence;
 375         struct syncobj_wait_entry *wait_cur, *wait_tmp;
 376         struct syncobj_eventfd_entry *ev_fd_cur, *ev_fd_tmp;
 377
 378         if (fence)
 379                 dma_fence_get(fence);
 380
 381         spin_lock(&syncobj->lock);
 382
 383         old_fence = rcu_dereference_protected(syncobj->fence,
 384                                               lockdep_is_held(&syncobj->lock));
 385         rcu_assign_pointer(syncobj->fence, fence);
 386
 387         if (fence != old_fence) {
 388                 list_for_each_entry_safe(wait_cur, wait_tmp, &syncobj->cb_list, node)
 389                         syncobj_wait_syncobj_func(syncobj, wait_cur);
 390                 list_for_each_entry_safe(ev_fd_cur, ev_fd_tmp, &syncobj->ev_fd_list, node)
 391                         syncobj_eventfd_entry_func(syncobj, ev_fd_cur);
 392         }
 393
 394         spin_unlock(&syncobj->lock);
 395
 396         dma_fence_put(old_fence);
 397 }
 398 EXPORT_SYMBOL(drm_syncobj_replace_fence);
 399
 400 /**
 401  * drm_syncobj_assign_null_handle - assign a stub fence to the sync object
 402  * @syncobj: sync object to assign the fence on
 403  *
 404  * Assign a already signaled stub fence to the sync object.
 405  */
 406 static int drm_syncobj_assign_null_handle(struct drm_syncobj *syncobj)
 407 {
 408         struct dma_fence *fence = dma_fence_allocate_private_stub(ktime_get());
 409
 410         if (!fence)
 411                 return -ENOMEM;
 412
 413         drm_syncobj_replace_fence(syncobj, fence);
 414         dma_fence_put(fence);
 415         return 0;
 416 }
 417
 418 /* 5s default for wait submission */
 419 #define DRM_SYNCOBJ_WAIT_FOR_SUBMIT_TIMEOUT 5000000000ULL
 420 /**
 421  * drm_syncobj_find_fence - lookup and reference the fence in a sync object
 422  * @file_private: drm file private pointer
 423  * @handle: sync object handle to lookup.
 424  * @point: timeline point
 425  * @flags: DRM_SYNCOBJ_WAIT_FLAGS_WAIT_FOR_SUBMIT or not
 426  * @fence: out parameter for the fence
 427  *
 428  * This is just a convenience function that combines drm_syncobj_find() and
 429  * drm_syncobj_fence_get().
 430  *
 431  * Returns 0 on success or a negative error value on failure. On success @fence
 432  * contains a reference to the fence, which must be released by calling
 433  * dma_fence_put().
 434  */
 435 int drm_syncobj_find_fence(struct drm_file *file_private,
 436                            u32 handle, u64 point, u64 flags,
 437                            struct dma_fence **fence)
 438 {
 439         struct drm_syncobj *syncobj = drm_syncobj_find(file_private, handle);
 440         struct syncobj_wait_entry wait;
 441         u64 timeout = nsecs_to_jiffies64(DRM_SYNCOBJ_WAIT_FOR_SUBMIT_TIMEOUT);
 442         int ret;
 443
 444         if (flags & ~DRM_SYNCOBJ_WAIT_FLAGS_WAIT_FOR_SUBMIT)
 445                 return -EINVAL;
 446
 447         if (!syncobj)
 448                 return -ENOENT;
 449
 450         /* Waiting for userspace with locks help is illegal cause that can
 451          * trivial deadlock with page faults for example. Make lockdep complain
 452          * about it early on.
 453          */
 454         if (flags & DRM_SYNCOBJ_WAIT_FLAGS_WAIT_FOR_SUBMIT) {
 455                 might_sleep();
 456                 lockdep_assert_none_held_once();
 457         }
 458
 459         *fence = drm_syncobj_fence_get(syncobj);
 460
 461         if (*fence) {
 462                 ret = dma_fence_chain_find_seqno(fence, point);
 463                 if (!ret) {
 464                         /* If the requested seqno is already signaled
 465                          * drm_syncobj_find_fence may return a NULL
 466                          * fence. To make sure the recipient gets
 467                          * signalled, use a new fence instead.
 468                          */
 469                         if (!*fence)
 470                                 *fence = dma_fence_get_stub();
 471
 472                         goto out;
 473                 }
 474                 dma_fence_put(*fence);
 475         } else {
 476                 ret = -EINVAL;
 477         }
 478
 479         if (!(flags & DRM_SYNCOBJ_WAIT_FLAGS_WAIT_FOR_SUBMIT))
 480                 goto out;
 481
 482         memset(&wait, 0, sizeof(wait));
 483         wait.task = current;
 484         wait.point = point;
 485         drm_syncobj_fence_add_wait(syncobj, &wait);
 486
 487         do {
 488                 set_current_state(TASK_INTERRUPTIBLE);
 489                 if (wait.fence) {
 490                         ret = 0;
 491                         break;
 492                 }
 493                 if (timeout == 0) {
 494                         ret = -ETIME;
 495                         break;
 496                 }
 497
 498                 if (signal_pending(current)) {
 499                         ret = -ERESTARTSYS;
 500                         break;
 501                 }
 502
 503                 timeout = schedule_timeout(timeout);
 504         } while (1);
 505
 506         __set_current_state(TASK_RUNNING);
 507         *fence = wait.fence;
 508
 509         if (wait.node.next)
 510                 drm_syncobj_remove_wait(syncobj, &wait);
 511
 512 out:
 513         drm_syncobj_put(syncobj);
 514
 515         return ret;
 516 }
 517 EXPORT_SYMBOL(drm_syncobj_find_fence);
 518
 519 /**
 520  * drm_syncobj_free - free a sync object.
 521  * @kref: kref to free.
 522  *
 523  * Only to be called from kref_put in drm_syncobj_put.
 524  */
 525 void drm_syncobj_free(struct kref *kref)
 526 {
 527         struct drm_syncobj *syncobj = container_of(kref,
 528                                                    struct drm_syncobj,
 529                                                    refcount);
 530         struct syncobj_eventfd_entry *ev_fd_cur, *ev_fd_tmp;
 531
 532         drm_syncobj_replace_fence(syncobj, NULL);
 533
 534         list_for_each_entry_safe(ev_fd_cur, ev_fd_tmp, &syncobj->ev_fd_list, node)
 535                 syncobj_eventfd_entry_free(ev_fd_cur);
 536
 537         kfree(syncobj);
 538 }
 539 EXPORT_SYMBOL(drm_syncobj_free);
 540
 541 /**
 542  * drm_syncobj_create - create a new syncobj
 543  * @out_syncobj: returned syncobj
 544  * @flags: DRM_SYNCOBJ_* flags
 545  * @fence: if non-NULL, the syncobj will represent this fence
 546  *
 547  * This is the first function to create a sync object. After creating, drivers
 548  * probably want to make it available to userspace, either through
 549  * drm_syncobj_get_handle() or drm_syncobj_get_fd().
 550  *
 551  * Returns 0 on success or a negative error value on failure.
 552  */
 553 int drm_syncobj_create(struct drm_syncobj **out_syncobj, uint32_t flags,
 554                        struct dma_fence *fence)
 555 {
 556         int ret;
 557         struct drm_syncobj *syncobj;
 558
 559         syncobj = kzalloc(sizeof(struct drm_syncobj), GFP_KERNEL);
 560         if (!syncobj)
 561                 return -ENOMEM;
 562
 563         kref_init(&syncobj->refcount);
 564         INIT_LIST_HEAD(&syncobj->cb_list);
 565         INIT_LIST_HEAD(&syncobj->ev_fd_list);
 566         spin_lock_init(&syncobj->lock);
 567
 568         if (flags & DRM_SYNCOBJ_CREATE_SIGNALED) {
 569                 ret = drm_syncobj_assign_null_handle(syncobj);
 570                 if (ret < 0) {
 571                         drm_syncobj_put(syncobj);
 572                         return ret;
 573                 }
 574         }
 575
 576         if (fence)
 577                 drm_syncobj_replace_fence(syncobj, fence);
 578
 579         *out_syncobj = syncobj;
 580         return 0;
 581 }
 582 EXPORT_SYMBOL(drm_syncobj_create);
 583
 584 /**
 585  * drm_syncobj_get_handle - get a handle from a syncobj
 586  * @file_private: drm file private pointer
 587  * @syncobj: Sync object to export
 588  * @handle: out parameter with the new handle
 589  *
 590  * Exports a sync object created with drm_syncobj_create() as a handle on
 591  * @file_private to userspace.
 592  *
 593  * Returns 0 on success or a negative error value on failure.
 594  */
 595 int drm_syncobj_get_handle(struct drm_file *file_private,
 596                            struct drm_syncobj *syncobj, u32 *handle)
 597 {
 598         int ret;
 599
 600         /* take a reference to put in the idr */
 601         drm_syncobj_get(syncobj);
 602
 603         idr_preload(GFP_KERNEL);
 604         spin_lock(&file_private->syncobj_table_lock);
 605         ret = idr_alloc(&file_private->syncobj_idr, syncobj, 1, 0, GFP_NOWAIT);
 606         spin_unlock(&file_private->syncobj_table_lock);
 607
 608         idr_preload_end();
 609
 610         if (ret < 0) {
 611                 drm_syncobj_put(syncobj);
 612                 return ret;
 613         }
 614
 615         *handle = ret;
 616         return 0;
 617 }
 618 EXPORT_SYMBOL(drm_syncobj_get_handle);
 619
 620 static int drm_syncobj_create_as_handle(struct drm_file *file_private,
 621                                         u32 *handle, uint32_t flags)
 622 {
 623         int ret;
 624         struct drm_syncobj *syncobj;
 625
 626         ret = drm_syncobj_create(&syncobj, flags, NULL);
 627         if (ret)
 628                 return ret;
 629
 630         ret = drm_syncobj_get_handle(file_private, syncobj, handle);
 631         drm_syncobj_put(syncobj);
 632         return ret;
 633 }
 634
 635 static int drm_syncobj_destroy(struct drm_file *file_private,
 636                                u32 handle)
 637 {
 638         struct drm_syncobj *syncobj;
 639
 640         spin_lock(&file_private->syncobj_table_lock);
 641         syncobj = idr_remove(&file_private->syncobj_idr, handle);
 642         spin_unlock(&file_private->syncobj_table_lock);
 643
 644         if (!syncobj)
 645                 return -EINVAL;
 646
 647         drm_syncobj_put(syncobj);
 648         return 0;
 649 }
 650
 651 static int drm_syncobj_file_release(struct inode *inode, struct file *file)
 652 {
 653         struct drm_syncobj *syncobj = file->private_data;
 654
 655         drm_syncobj_put(syncobj);
 656         return 0;
 657 }
 658
 659 static const struct file_operations drm_syncobj_file_fops = {
 660         .release = drm_syncobj_file_release,
 661 };
 662
 663 /**
 664  * drm_syncobj_get_fd - get a file descriptor from a syncobj
 665  * @syncobj: Sync object to export
 666  * @p_fd: out parameter with the new file descriptor
 667  *
 668  * Exports a sync object created with drm_syncobj_create() as a file descriptor.
 669  *
 670  * Returns 0 on success or a negative error value on failure.
 671  */
 672 int drm_syncobj_get_fd(struct drm_syncobj *syncobj, int *p_fd)
 673 {
 674         struct file *file;
 675         int fd;
 676
 677         fd = get_unused_fd_flags(O_CLOEXEC);
 678         if (fd < 0)
 679                 return fd;
 680
 681         file = anon_inode_getfile("syncobj_file",
 682                                   &drm_syncobj_file_fops,
 683                                   syncobj, 0);
 684         if (IS_ERR(file)) {
 685                 put_unused_fd(fd);
 686                 return PTR_ERR(file);
 687         }
 688
 689         drm_syncobj_get(syncobj);
 690         fd_install(fd, file);
 691
 692         *p_fd = fd;
 693         return 0;
 694 }
 695 EXPORT_SYMBOL(drm_syncobj_get_fd);
 696
 697 static int drm_syncobj_handle_to_fd(struct drm_file *file_private,
 698                                     u32 handle, int *p_fd)
 699 {
 700         struct drm_syncobj *syncobj = drm_syncobj_find(file_private, handle);
 701         int ret;
 702
 703         if (!syncobj)
 704                 return -EINVAL;
 705
 706         ret = drm_syncobj_get_fd(syncobj, p_fd);
 707         drm_syncobj_put(syncobj);
 708         return ret;
 709 }
 710
 711 static int drm_syncobj_fd_to_handle(struct drm_file *file_private,
 712                                     int fd, u32 *handle)
 713 {
 714         struct drm_syncobj *syncobj;
 715         CLASS(fd, f)(fd);
 716         int ret;
 717
 718         if (fd_empty(f))
 719                 return -EINVAL;
 720
 721         if (fd_file(f)->f_op != &drm_syncobj_file_fops)
 722                 return -EINVAL;
 723
 724         /* take a reference to put in the idr */
 725         syncobj = fd_file(f)->private_data;
 726         drm_syncobj_get(syncobj);
 727
 728         idr_preload(GFP_KERNEL);
 729         spin_lock(&file_private->syncobj_table_lock);
 730         ret = idr_alloc(&file_private->syncobj_idr, syncobj, 1, 0, GFP_NOWAIT);
 731         spin_unlock(&file_private->syncobj_table_lock);
 732         idr_preload_end();
 733
 734         if (ret > 0) {
 735                 *handle = ret;
 736                 ret = 0;
 737         } else
 738                 drm_syncobj_put(syncobj);
 739
 740         return ret;
 741 }
 742
 743 static int drm_syncobj_import_sync_file_fence(struct drm_file *file_private,
 744                                               int fd, int handle)
 745 {
 746         struct dma_fence *fence = sync_file_get_fence(fd);
 747         struct drm_syncobj *syncobj;
 748
 749         if (!fence)
 750                 return -EINVAL;
 751
 752         syncobj = drm_syncobj_find(file_private, handle);
 753         if (!syncobj) {
 754                 dma_fence_put(fence);
 755                 return -ENOENT;
 756         }
 757
 758         drm_syncobj_replace_fence(syncobj, fence);
 759         dma_fence_put(fence);
 760         drm_syncobj_put(syncobj);
 761         return 0;
 762 }
 763
 764 static int drm_syncobj_export_sync_file(struct drm_file *file_private,
 765                                         int handle, int *p_fd)
 766 {
 767         int ret;
 768         struct dma_fence *fence;
 769         struct sync_file *sync_file;
 770         int fd = get_unused_fd_flags(O_CLOEXEC);
 771
 772         if (fd < 0)
 773                 return fd;
 774
 775         ret = drm_syncobj_find_fence(file_private, handle, 0, 0, &fence);
 776         if (ret)
 777                 goto err_put_fd;
 778
 779         sync_file = sync_file_create(fence);
 780
 781         dma_fence_put(fence);
 782
 783         if (!sync_file) {
 784                 ret = -EINVAL;
 785                 goto err_put_fd;
 786         }
 787
 788         fd_install(fd, sync_file->file);
 789
 790         *p_fd = fd;
 791         return 0;
 792 err_put_fd:
 793         put_unused_fd(fd);
 794         return ret;
 795 }
 796 /**
 797  * drm_syncobj_open - initializes syncobj file-private structures at devnode open time
 798  * @file_private: drm file-private structure to set up
 799  *
 800  * Called at device open time, sets up the structure for handling refcounting
 801  * of sync objects.
 802  */
 803 void
 804 drm_syncobj_open(struct drm_file *file_private)
 805 {
 806         idr_init_base(&file_private->syncobj_idr, 1);
 807         spin_lock_init(&file_private->syncobj_table_lock);
 808 }
 809
 810 static int
 811 drm_syncobj_release_handle(int id, void *ptr, void *data)
 812 {
 813         struct drm_syncobj *syncobj = ptr;
 814
 815         drm_syncobj_put(syncobj);
 816         return 0;
 817 }
 818
 819 /**
 820  * drm_syncobj_release - release file-private sync object resources
 821  * @file_private: drm file-private structure to clean up
 822  *
 823  * Called at close time when the filp is going away.
 824  *
 825  * Releases any remaining references on objects by this filp.
 826  */
 827 void
 828 drm_syncobj_release(struct drm_file *file_private)
 829 {
 830         idr_for_each(&file_private->syncobj_idr,
 831                      &drm_syncobj_release_handle, file_private);
 832         idr_destroy(&file_private->syncobj_idr);
 833 }
 834
 835 int
 836 drm_syncobj_create_ioctl(struct drm_device *dev, void *data,
 837                          struct drm_file *file_private)
 838 {
 839         struct drm_syncobj_create *args = data;
 840
 841         if (!drm_core_check_feature(dev, DRIVER_SYNCOBJ))
 842                 return -EOPNOTSUPP;
 843
 844         /* no valid flags yet */
 845         if (args->flags & ~DRM_SYNCOBJ_CREATE_SIGNALED)
 846                 return -EINVAL;
 847
 848         return drm_syncobj_create_as_handle(file_private,
 849                                             &args->handle, args->flags);
 850 }
 851
 852 int
 853 drm_syncobj_destroy_ioctl(struct drm_device *dev, void *data,
 854                           struct drm_file *file_private)
 855 {
 856         struct drm_syncobj_destroy *args = data;
 857
 858         if (!drm_core_check_feature(dev, DRIVER_SYNCOBJ))
 859                 return -EOPNOTSUPP;
 860
 861         /* make sure padding is empty */
 862         if (args->pad)
 863                 return -EINVAL;
 864         return drm_syncobj_destroy(file_private, args->handle);
 865 }
 866
 867 int
 868 drm_syncobj_handle_to_fd_ioctl(struct drm_device *dev, void *data,
 869                                    struct drm_file *file_private)
 870 {
 871         struct drm_syncobj_handle *args = data;
 872
 873         if (!drm_core_check_feature(dev, DRIVER_SYNCOBJ))
 874                 return -EOPNOTSUPP;
 875
 876         if (args->pad)
 877                 return -EINVAL;
 878
 879         if (args->flags != 0 &&
 880             args->flags != DRM_SYNCOBJ_HANDLE_TO_FD_FLAGS_EXPORT_SYNC_FILE)
 881                 return -EINVAL;
 882
 883         if (args->flags & DRM_SYNCOBJ_HANDLE_TO_FD_FLAGS_EXPORT_SYNC_FILE)
 884                 return drm_syncobj_export_sync_file(file_private, args->handle,
 885                                                     &args->fd);
 886
 887         return drm_syncobj_handle_to_fd(file_private, args->handle,
 888                                         &args->fd);
 889 }
 890
 891 int
 892 drm_syncobj_fd_to_handle_ioctl(struct drm_device *dev, void *data,
 893                                    struct drm_file *file_private)
 894 {
 895         struct drm_syncobj_handle *args = data;
 896
 897         if (!drm_core_check_feature(dev, DRIVER_SYNCOBJ))
 898                 return -EOPNOTSUPP;
 899
 900         if (args->pad)
 901                 return -EINVAL;
 902
 903         if (args->flags != 0 &&
 904             args->flags != DRM_SYNCOBJ_FD_TO_HANDLE_FLAGS_IMPORT_SYNC_FILE)
 905                 return -EINVAL;
 906
 907         if (args->flags & DRM_SYNCOBJ_FD_TO_HANDLE_FLAGS_IMPORT_SYNC_FILE)
 908                 return drm_syncobj_import_sync_file_fence(file_private,
 909                                                           args->fd,
 910                                                           args->handle);
 911
 912         return drm_syncobj_fd_to_handle(file_private, args->fd,
 913                                         &args->handle);
 914 }
 915
 916 static int drm_syncobj_transfer_to_timeline(struct drm_file *file_private,
 917                                             struct drm_syncobj_transfer *args)
 918 {
 919         struct drm_syncobj *timeline_syncobj = NULL;
 920         struct dma_fence *fence, *tmp;
 921         struct dma_fence_chain *chain;
 922         int ret;
 923
 924         timeline_syncobj = drm_syncobj_find(file_private, args->dst_handle);
 925         if (!timeline_syncobj) {
 926                 return -ENOENT;
 927         }
 928         ret = drm_syncobj_find_fence(file_private, args->src_handle,
 929                                      args->src_point, args->flags,
 930                                      &tmp);
 931         if (ret)
 932                 goto err_put_timeline;
 933
 934         fence = dma_fence_unwrap_merge(tmp);
 935         dma_fence_put(tmp);
 936         if (!fence) {
 937                 ret = -ENOMEM;
 938                 goto err_put_timeline;
 939         }
 940
 941         chain = dma_fence_chain_alloc();
 942         if (!chain) {
 943                 ret = -ENOMEM;
 944                 goto err_free_fence;
 945         }
 946
 947         drm_syncobj_add_point(timeline_syncobj, chain, fence, args->dst_point);
 948 err_free_fence:
 949         dma_fence_put(fence);
 950 err_put_timeline:
 951         drm_syncobj_put(timeline_syncobj);
 952
 953         return ret;
 954 }
 955
 956 static int
 957 drm_syncobj_transfer_to_binary(struct drm_file *file_private,
 958                                struct drm_syncobj_transfer *args)
 959 {
 960         struct drm_syncobj *binary_syncobj = NULL;
 961         struct dma_fence *fence;
 962         int ret;
 963
 964         binary_syncobj = drm_syncobj_find(file_private, args->dst_handle);
 965         if (!binary_syncobj)
 966                 return -ENOENT;
 967         ret = drm_syncobj_find_fence(file_private, args->src_handle,
 968                                      args->src_point, args->flags, &fence);
 969         if (ret)
 970                 goto err;
 971         drm_syncobj_replace_fence(binary_syncobj, fence);
 972         dma_fence_put(fence);
 973 err:
 974         drm_syncobj_put(binary_syncobj);
 975
 976         return ret;
 977 }
 978 int
 979 drm_syncobj_transfer_ioctl(struct drm_device *dev, void *data,
 980                            struct drm_file *file_private)
 981 {
 982         struct drm_syncobj_transfer *args = data;
 983         int ret;
 984
 985         if (!drm_core_check_feature(dev, DRIVER_SYNCOBJ_TIMELINE))
 986                 return -EOPNOTSUPP;
 987
 988         if (args->pad)
 989                 return -EINVAL;
 990
 991         if (args->dst_point)
 992                 ret = drm_syncobj_transfer_to_timeline(file_private, args);
 993         else
 994                 ret = drm_syncobj_transfer_to_binary(file_private, args);
 995
 996         return ret;
 997 }
 998
 999 static void syncobj_wait_fence_func(struct dma_fence *fence,
1000                                     struct dma_fence_cb *cb)
1001 {
1002         struct syncobj_wait_entry *wait =
1003                 container_of(cb, struct syncobj_wait_entry, fence_cb);
1004
1005         wake_up_process(wait->task);
1006 }
1007
1008 static void syncobj_wait_syncobj_func(struct drm_syncobj *syncobj,
1009                                       struct syncobj_wait_entry *wait)
1010 {
1011         struct dma_fence *fence;
1012
1013         /* This happens inside the syncobj lock */
1014         fence = rcu_dereference_protected(syncobj->fence,
1015                                           lockdep_is_held(&syncobj->lock));
1016         dma_fence_get(fence);
1017         if (!fence || dma_fence_chain_find_seqno(&fence, wait->point)) {
1018                 dma_fence_put(fence);
1019                 return;
1020         } else if (!fence) {
1021                 wait->fence = dma_fence_get_stub();
1022         } else {
1023                 wait->fence = fence;
1024         }
1025
1026         wake_up_process(wait->task);
1027         list_del_init(&wait->node);
1028 }
1029
1030 static signed long drm_syncobj_array_wait_timeout(struct drm_syncobj **syncobjs,
1031                                                   void __user *user_points,
1032                                                   uint32_t count,
1033                                                   uint32_t flags,
1034                                                   signed long timeout,
1035                                                   uint32_t *idx,
1036                                                   ktime_t *deadline)
1037 {
1038         struct syncobj_wait_entry *entries;
1039         struct dma_fence *fence;
1040         uint64_t *points;
1041         uint32_t signaled_count, i;
1042
1043         if (flags & (DRM_SYNCOBJ_WAIT_FLAGS_WAIT_FOR_SUBMIT |
1044                      DRM_SYNCOBJ_WAIT_FLAGS_WAIT_AVAILABLE)) {
1045                 might_sleep();
1046                 lockdep_assert_none_held_once();
1047         }
1048
1049         points = kmalloc_array(count, sizeof(*points), GFP_KERNEL);
1050         if (points == NULL)
1051                 return -ENOMEM;
1052
1053         if (!user_points) {
1054                 memset(points, 0, count * sizeof(uint64_t));
1055
1056         } else if (copy_from_user(points, user_points,
1057                                   sizeof(uint64_t) * count)) {
1058                 timeout = -EFAULT;
1059                 goto err_free_points;
1060         }
1061
1062         entries = kcalloc(count, sizeof(*entries), GFP_KERNEL);
1063         if (!entries) {
1064                 timeout = -ENOMEM;
1065                 goto err_free_points;
1066         }
1067         /* Walk the list of sync objects and initialize entries.  We do
1068          * this up-front so that we can properly return -EINVAL if there is
1069          * a syncobj with a missing fence and then never have the chance of
1070          * returning -EINVAL again.
1071          */
1072         signaled_count = 0;
1073         for (i = 0; i < count; ++i) {
1074                 struct dma_fence *fence;
1075
1076                 entries[i].task = current;
1077                 entries[i].point = points[i];
1078                 fence = drm_syncobj_fence_get(syncobjs[i]);
1079                 if (!fence || dma_fence_chain_find_seqno(&fence, points[i])) {
1080                         dma_fence_put(fence);
1081                         if (flags & (DRM_SYNCOBJ_WAIT_FLAGS_WAIT_FOR_SUBMIT |
1082                                      DRM_SYNCOBJ_WAIT_FLAGS_WAIT_AVAILABLE)) {
1083                                 continue;
1084                         } else {
1085                                 timeout = -EINVAL;
1086                                 goto cleanup_entries;
1087                         }
1088                 }
1089
1090                 if (fence)
1091                         entries[i].fence = fence;
1092                 else
1093                         entries[i].fence = dma_fence_get_stub();
1094
1095                 if ((flags & DRM_SYNCOBJ_WAIT_FLAGS_WAIT_AVAILABLE) ||
1096                     dma_fence_is_signaled(entries[i].fence)) {
1097                         if (signaled_count == 0 && idx)
1098                                 *idx = i;
1099                         signaled_count++;
1100                 }
1101         }
1102
1103         if (signaled_count == count ||
1104             (signaled_count > 0 &&
1105              !(flags & DRM_SYNCOBJ_WAIT_FLAGS_WAIT_ALL)))
1106                 goto cleanup_entries;
1107
1108         /* There's a very annoying laxness in the dma_fence API here, in
1109          * that backends are not required to automatically report when a
1110          * fence is signaled prior to fence->ops->enable_signaling() being
1111          * called.  So here if we fail to match signaled_count, we need to
1112          * fallthough and try a 0 timeout wait!
1113          */
1114
1115         if (flags & (DRM_SYNCOBJ_WAIT_FLAGS_WAIT_FOR_SUBMIT |
1116                      DRM_SYNCOBJ_WAIT_FLAGS_WAIT_AVAILABLE)) {
1117                 for (i = 0; i < count; ++i)
1118                         drm_syncobj_fence_add_wait(syncobjs[i], &entries[i]);
1119         }
1120
1121         if (deadline) {
1122                 for (i = 0; i < count; ++i) {
1123                         fence = entries[i].fence;
1124                         if (!fence)
1125                                 continue;
1126                         dma_fence_set_deadline(fence, *deadline);
1127                 }
1128         }
1129
1130         do {
1131                 set_current_state(TASK_INTERRUPTIBLE);
1132
1133                 signaled_count = 0;
1134                 for (i = 0; i < count; ++i) {
1135                         fence = entries[i].fence;
1136                         if (!fence)
1137                                 continue;
1138
1139                         if ((flags & DRM_SYNCOBJ_WAIT_FLAGS_WAIT_AVAILABLE) ||
1140                             dma_fence_is_signaled(fence) ||
1141                             (!entries[i].fence_cb.func &&
1142                              dma_fence_add_callback(fence,
1143                                                     &entries[i].fence_cb,
1144                                                     syncobj_wait_fence_func))) {
1145                                 /* The fence has been signaled */
1146                                 if (flags & DRM_SYNCOBJ_WAIT_FLAGS_WAIT_ALL) {
1147                                         signaled_count++;
1148                                 } else {
1149                                         if (idx)
1150                                                 *idx = i;
1151                                         goto done_waiting;
1152                                 }
1153                         }
1154                 }
1155
1156                 if (signaled_count == count)
1157                         goto done_waiting;
1158
1159                 if (timeout == 0) {
1160                         timeout = -ETIME;
1161                         goto done_waiting;
1162                 }
1163
1164                 if (signal_pending(current)) {
1165                         timeout = -ERESTARTSYS;
1166                         goto done_waiting;
1167                 }
1168
1169                 timeout = schedule_timeout(timeout);
1170         } while (1);
1171
1172 done_waiting:
1173         __set_current_state(TASK_RUNNING);
1174
1175 cleanup_entries:
1176         for (i = 0; i < count; ++i) {
1177                 drm_syncobj_remove_wait(syncobjs[i], &entries[i]);
1178                 if (entries[i].fence_cb.func)
1179                         dma_fence_remove_callback(entries[i].fence,
1180                                                   &entries[i].fence_cb);
1181                 dma_fence_put(entries[i].fence);
1182         }
1183         kfree(entries);
1184
1185 err_free_points:
1186         kfree(points);
1187
1188         return timeout;
1189 }
1190
1191 /**
1192  * drm_timeout_abs_to_jiffies - calculate jiffies timeout from absolute value
1193  *
1194  * @timeout_nsec: timeout nsec component in ns, 0 for poll
1195  *
1196  * Calculate the timeout in jiffies from an absolute time in sec/nsec.
1197  */
1198 signed long drm_timeout_abs_to_jiffies(int64_t timeout_nsec)
1199 {
1200         ktime_t abs_timeout, now;
1201         u64 timeout_ns, timeout_jiffies64;
1202
1203         /* make 0 timeout means poll - absolute 0 doesn't seem valid */
1204         if (timeout_nsec == 0)
1205                 return 0;
1206
1207         abs_timeout = ns_to_ktime(timeout_nsec);
1208         now = ktime_get();
1209
1210         if (!ktime_after(abs_timeout, now))
1211                 return 0;
1212
1213         timeout_ns = ktime_to_ns(ktime_sub(abs_timeout, now));
1214
1215         timeout_jiffies64 = nsecs_to_jiffies64(timeout_ns);
1216         /*  clamp timeout to avoid infinite timeout */
1217         if (timeout_jiffies64 >= MAX_SCHEDULE_TIMEOUT - 1)
1218                 return MAX_SCHEDULE_TIMEOUT - 1;
1219
1220         return timeout_jiffies64 + 1;
1221 }
1222 EXPORT_SYMBOL(drm_timeout_abs_to_jiffies);
1223
1224 static int drm_syncobj_array_wait(struct drm_device *dev,
1225                                   struct drm_file *file_private,
1226                                   struct drm_syncobj_wait *wait,
1227                                   struct drm_syncobj_timeline_wait *timeline_wait,
1228                                   struct drm_syncobj **syncobjs, bool timeline,
1229                                   ktime_t *deadline)
1230 {
1231         signed long timeout = 0;
1232         uint32_t first = ~0;
1233
1234         if (!timeline) {
1235                 timeout = drm_timeout_abs_to_jiffies(wait->timeout_nsec);
1236                 timeout = drm_syncobj_array_wait_timeout(syncobjs,
1237                                                          NULL,
1238                                                          wait->count_handles,
1239                                                          wait->flags,
1240                                                          timeout, &first,
1241                                                          deadline);
1242                 if (timeout < 0)
1243                         return timeout;
1244                 wait->first_signaled = first;
1245         } else {
1246                 timeout = drm_timeout_abs_to_jiffies(timeline_wait->timeout_nsec);
1247                 timeout = drm_syncobj_array_wait_timeout(syncobjs,
1248                                                          u64_to_user_ptr(timeline_wait->points),
1249                                                          timeline_wait->count_handles,
1250                                                          timeline_wait->flags,
1251                                                          timeout, &first,
1252                                                          deadline);
1253                 if (timeout < 0)
1254                         return timeout;
1255                 timeline_wait->first_signaled = first;
1256         }
1257         return 0;
1258 }
1259
1260 static int drm_syncobj_array_find(struct drm_file *file_private,
1261                                   void __user *user_handles,
1262                                   uint32_t count_handles,
1263                                   struct drm_syncobj ***syncobjs_out)
1264 {
1265         uint32_t i, *handles;
1266         struct drm_syncobj **syncobjs;
1267         int ret;
1268
1269         handles = kmalloc_array(count_handles, sizeof(*handles), GFP_KERNEL);
1270         if (handles == NULL)
1271                 return -ENOMEM;
1272
1273         if (copy_from_user(handles, user_handles,
1274                            sizeof(uint32_t) * count_handles)) {
1275                 ret = -EFAULT;
1276                 goto err_free_handles;
1277         }
1278
1279         syncobjs = kmalloc_array(count_handles, sizeof(*syncobjs), GFP_KERNEL);
1280         if (syncobjs == NULL) {
1281                 ret = -ENOMEM;
1282                 goto err_free_handles;
1283         }
1284
1285         for (i = 0; i < count_handles; i++) {
1286                 syncobjs[i] = drm_syncobj_find(file_private, handles[i]);
1287                 if (!syncobjs[i]) {
1288                         ret = -ENOENT;
1289                         goto err_put_syncobjs;
1290                 }
1291         }
1292
1293         kfree(handles);
1294         *syncobjs_out = syncobjs;
1295         return 0;
1296
1297 err_put_syncobjs:
1298         while (i-- > 0)
1299                 drm_syncobj_put(syncobjs[i]);
1300         kfree(syncobjs);
1301 err_free_handles:
1302         kfree(handles);
1303
1304         return ret;
1305 }
1306
1307 static void drm_syncobj_array_free(struct drm_syncobj **syncobjs,
1308                                    uint32_t count)
1309 {
1310         uint32_t i;
1311
1312         for (i = 0; i < count; i++)
1313                 drm_syncobj_put(syncobjs[i]);
1314         kfree(syncobjs);
1315 }
1316
1317 int
1318 drm_syncobj_wait_ioctl(struct drm_device *dev, void *data,
1319                        struct drm_file *file_private)
1320 {
1321         struct drm_syncobj_wait *args = data;
1322         struct drm_syncobj **syncobjs;
1323         unsigned int possible_flags;
1324         ktime_t t, *tp = NULL;
1325         int ret = 0;
1326
1327         if (!drm_core_check_feature(dev, DRIVER_SYNCOBJ))
1328                 return -EOPNOTSUPP;
1329
1330         possible_flags = DRM_SYNCOBJ_WAIT_FLAGS_WAIT_ALL |
1331                          DRM_SYNCOBJ_WAIT_FLAGS_WAIT_FOR_SUBMIT |
1332                          DRM_SYNCOBJ_WAIT_FLAGS_WAIT_DEADLINE;
1333
1334         if (args->flags & ~possible_flags)
1335                 return -EINVAL;
1336
1337         if (args->count_handles == 0)
1338                 return 0;
1339
1340         ret = drm_syncobj_array_find(file_private,
1341                                      u64_to_user_ptr(args->handles),
1342                                      args->count_handles,
1343                                      &syncobjs);
1344         if (ret < 0)
1345                 return ret;
1346
1347         if (args->flags & DRM_SYNCOBJ_WAIT_FLAGS_WAIT_DEADLINE) {
1348                 t = ns_to_ktime(args->deadline_nsec);
1349                 tp = &t;
1350         }
1351
1352         ret = drm_syncobj_array_wait(dev, file_private,
1353                                      args, NULL, syncobjs, false, tp);
1354
1355         drm_syncobj_array_free(syncobjs, args->count_handles);
1356
1357         return ret;
1358 }
1359
1360 int
1361 drm_syncobj_timeline_wait_ioctl(struct drm_device *dev, void *data,
1362                                 struct drm_file *file_private)
1363 {
1364         struct drm_syncobj_timeline_wait *args = data;
1365         struct drm_syncobj **syncobjs;
1366         unsigned int possible_flags;
1367         ktime_t t, *tp = NULL;
1368         int ret = 0;
1369
1370         if (!drm_core_check_feature(dev, DRIVER_SYNCOBJ_TIMELINE))
1371                 return -EOPNOTSUPP;
1372
1373         possible_flags = DRM_SYNCOBJ_WAIT_FLAGS_WAIT_ALL |
1374                          DRM_SYNCOBJ_WAIT_FLAGS_WAIT_FOR_SUBMIT |
1375                          DRM_SYNCOBJ_WAIT_FLAGS_WAIT_AVAILABLE |
1376                          DRM_SYNCOBJ_WAIT_FLAGS_WAIT_DEADLINE;
1377
1378         if (args->flags & ~possible_flags)
1379                 return -EINVAL;
1380
1381         if (args->count_handles == 0)
1382                 return 0;
1383
1384         ret = drm_syncobj_array_find(file_private,
1385                                      u64_to_user_ptr(args->handles),
1386                                      args->count_handles,
1387                                      &syncobjs);
1388         if (ret < 0)
1389                 return ret;
1390
1391         if (args->flags & DRM_SYNCOBJ_WAIT_FLAGS_WAIT_DEADLINE) {
1392                 t = ns_to_ktime(args->deadline_nsec);
1393                 tp = &t;
1394         }
1395
1396         ret = drm_syncobj_array_wait(dev, file_private,
1397                                      NULL, args, syncobjs, true, tp);
1398
1399         drm_syncobj_array_free(syncobjs, args->count_handles);
1400
1401         return ret;
1402 }
1403
1404 static void syncobj_eventfd_entry_fence_func(struct dma_fence *fence,
1405                                              struct dma_fence_cb *cb)
1406 {
1407         struct syncobj_eventfd_entry *entry =
1408                 container_of(cb, struct syncobj_eventfd_entry, fence_cb);
1409
1410         eventfd_signal(entry->ev_fd_ctx);
1411         syncobj_eventfd_entry_free(entry);
1412 }
1413
1414 static void
1415 syncobj_eventfd_entry_func(struct drm_syncobj *syncobj,
1416                            struct syncobj_eventfd_entry *entry)
1417 {
1418         int ret;
1419         struct dma_fence *fence;
1420
1421         /* This happens inside the syncobj lock */
1422         fence = dma_fence_get(rcu_dereference_protected(syncobj->fence, 1));
1423         if (!fence)
1424                 return;
1425
1426         ret = dma_fence_chain_find_seqno(&fence, entry->point);
1427         if (ret != 0) {
1428                 /* The given seqno has not been submitted yet. */
1429                 dma_fence_put(fence);
1430                 return;
1431         } else if (!fence) {
1432                 /* If dma_fence_chain_find_seqno returns 0 but sets the fence
1433                  * to NULL, it implies that the given seqno is signaled and a
1434                  * later seqno has already been submitted. Assign a stub fence
1435                  * so that the eventfd still gets signaled below.
1436                  */
1437                 fence = dma_fence_get_stub();
1438         }
1439
1440         list_del_init(&entry->node);
1441         entry->fence = fence;
1442
1443         if (entry->flags & DRM_SYNCOBJ_WAIT_FLAGS_WAIT_AVAILABLE) {
1444                 eventfd_signal(entry->ev_fd_ctx);
1445                 syncobj_eventfd_entry_free(entry);
1446         } else {
1447                 ret = dma_fence_add_callback(fence, &entry->fence_cb,
1448                                              syncobj_eventfd_entry_fence_func);
1449                 if (ret == -ENOENT) {
1450                         eventfd_signal(entry->ev_fd_ctx);
1451                         syncobj_eventfd_entry_free(entry);
1452                 }
1453         }
1454 }
1455
1456 int
1457 drm_syncobj_eventfd_ioctl(struct drm_device *dev, void *data,
1458                           struct drm_file *file_private)
1459 {
1460         struct drm_syncobj_eventfd *args = data;
1461         struct drm_syncobj *syncobj;
1462         struct eventfd_ctx *ev_fd_ctx;
1463         struct syncobj_eventfd_entry *entry;
1464         int ret;
1465
1466         if (!drm_core_check_feature(dev, DRIVER_SYNCOBJ_TIMELINE))
1467                 return -EOPNOTSUPP;
1468
1469         if (args->flags & ~DRM_SYNCOBJ_WAIT_FLAGS_WAIT_AVAILABLE)
1470                 return -EINVAL;
1471
1472         if (args->pad)
1473                 return -EINVAL;
1474
1475         syncobj = drm_syncobj_find(file_private, args->handle);
1476         if (!syncobj)
1477                 return -ENOENT;
1478
1479         ev_fd_ctx = eventfd_ctx_fdget(args->fd);
1480         if (IS_ERR(ev_fd_ctx)) {
1481                 ret = PTR_ERR(ev_fd_ctx);
1482                 goto err_fdget;
1483         }
1484
1485         entry = kzalloc(sizeof(*entry), GFP_KERNEL);
1486         if (!entry) {
1487                 ret = -ENOMEM;
1488                 goto err_kzalloc;
1489         }
1490         entry->syncobj = syncobj;
1491         entry->ev_fd_ctx = ev_fd_ctx;
1492         entry->point = args->point;
1493         entry->flags = args->flags;
1494
1495         drm_syncobj_add_eventfd(syncobj, entry);
1496         drm_syncobj_put(syncobj);
1497
1498         return 0;
1499
1500 err_kzalloc:
1501         eventfd_ctx_put(ev_fd_ctx);
1502 err_fdget:
1503         drm_syncobj_put(syncobj);
1504         return ret;
1505 }
1506
1507 int
1508 drm_syncobj_reset_ioctl(struct drm_device *dev, void *data,
1509                         struct drm_file *file_private)
1510 {
1511         struct drm_syncobj_array *args = data;
1512         struct drm_syncobj **syncobjs;
1513         uint32_t i;
1514         int ret;
1515
1516         if (!drm_core_check_feature(dev, DRIVER_SYNCOBJ))
1517                 return -EOPNOTSUPP;
1518
1519         if (args->pad != 0)
1520                 return -EINVAL;
1521
1522         if (args->count_handles == 0)
1523                 return -EINVAL;
1524
1525         ret = drm_syncobj_array_find(file_private,
1526                                      u64_to_user_ptr(args->handles),
1527                                      args->count_handles,
1528                                      &syncobjs);
1529         if (ret < 0)
1530                 return ret;
1531
1532         for (i = 0; i < args->count_handles; i++)
1533                 drm_syncobj_replace_fence(syncobjs[i], NULL);
1534
1535         drm_syncobj_array_free(syncobjs, args->count_handles);
1536
1537         return 0;
1538 }
1539
1540 int
1541 drm_syncobj_signal_ioctl(struct drm_device *dev, void *data,
1542                          struct drm_file *file_private)
1543 {
1544         struct drm_syncobj_array *args = data;
1545         struct drm_syncobj **syncobjs;
1546         uint32_t i;
1547         int ret;
1548
1549         if (!drm_core_check_feature(dev, DRIVER_SYNCOBJ))
1550                 return -EOPNOTSUPP;
1551
1552         if (args->pad != 0)
1553                 return -EINVAL;
1554
1555         if (args->count_handles == 0)
1556                 return -EINVAL;
1557
1558         ret = drm_syncobj_array_find(file_private,
1559                                      u64_to_user_ptr(args->handles),
1560                                      args->count_handles,
1561                                      &syncobjs);
1562         if (ret < 0)
1563                 return ret;
1564
1565         for (i = 0; i < args->count_handles; i++) {
1566                 ret = drm_syncobj_assign_null_handle(syncobjs[i]);
1567                 if (ret < 0)
1568                         break;
1569         }
1570
1571         drm_syncobj_array_free(syncobjs, args->count_handles);
1572
1573         return ret;
1574 }
1575
1576 int
1577 drm_syncobj_timeline_signal_ioctl(struct drm_device *dev, void *data,
1578                                   struct drm_file *file_private)
1579 {
1580         struct drm_syncobj_timeline_array *args = data;
1581         struct drm_syncobj **syncobjs;
1582         struct dma_fence_chain **chains;
1583         uint64_t *points;
1584         uint32_t i, j;
1585         int ret;
1586
1587         if (!drm_core_check_feature(dev, DRIVER_SYNCOBJ_TIMELINE))
1588                 return -EOPNOTSUPP;
1589
1590         if (args->flags != 0)
1591                 return -EINVAL;
1592
1593         if (args->count_handles == 0)
1594                 return -EINVAL;
1595
1596         ret = drm_syncobj_array_find(file_private,
1597                                      u64_to_user_ptr(args->handles),
1598                                      args->count_handles,
1599                                      &syncobjs);
1600         if (ret < 0)
1601                 return ret;
1602
1603         points = kmalloc_array(args->count_handles, sizeof(*points),
1604                                GFP_KERNEL);
1605         if (!points) {
1606                 ret = -ENOMEM;
1607                 goto out;
1608         }
1609         if (!u64_to_user_ptr(args->points)) {
1610                 memset(points, 0, args->count_handles * sizeof(uint64_t));
1611         } else if (copy_from_user(points, u64_to_user_ptr(args->points),
1612                                   sizeof(uint64_t) * args->count_handles)) {
1613                 ret = -EFAULT;
1614                 goto err_points;
1615         }
1616
1617         chains = kmalloc_array(args->count_handles, sizeof(void *), GFP_KERNEL);
1618         if (!chains) {
1619                 ret = -ENOMEM;
1620                 goto err_points;
1621         }
1622         for (i = 0; i < args->count_handles; i++) {
1623                 chains[i] = dma_fence_chain_alloc();
1624                 if (!chains[i]) {
1625                         for (j = 0; j < i; j++)
1626                                 dma_fence_chain_free(chains[j]);
1627                         ret = -ENOMEM;
1628                         goto err_chains;
1629                 }
1630         }
1631
1632         for (i = 0; i < args->count_handles; i++) {
1633                 struct dma_fence *fence = dma_fence_get_stub();
1634
1635                 drm_syncobj_add_point(syncobjs[i], chains[i],
1636                                       fence, points[i]);
1637                 dma_fence_put(fence);
1638         }
1639 err_chains:
1640         kfree(chains);
1641 err_points:
1642         kfree(points);
1643 out:
1644         drm_syncobj_array_free(syncobjs, args->count_handles);
1645
1646         return ret;
1647 }
1648
1649 int drm_syncobj_query_ioctl(struct drm_device *dev, void *data,
1650                             struct drm_file *file_private)
1651 {
1652         struct drm_syncobj_timeline_array *args = data;
1653         struct drm_syncobj **syncobjs;
1654         uint64_t __user *points = u64_to_user_ptr(args->points);
1655         uint32_t i;
1656         int ret;
1657
1658         if (!drm_core_check_feature(dev, DRIVER_SYNCOBJ_TIMELINE))
1659                 return -EOPNOTSUPP;
1660
1661         if (args->flags & ~DRM_SYNCOBJ_QUERY_FLAGS_LAST_SUBMITTED)
1662                 return -EINVAL;
1663
1664         if (args->count_handles == 0)
1665                 return -EINVAL;
1666
1667         ret = drm_syncobj_array_find(file_private,
1668                                      u64_to_user_ptr(args->handles),
1669                                      args->count_handles,
1670                                      &syncobjs);
1671         if (ret < 0)
1672                 return ret;
1673
1674         for (i = 0; i < args->count_handles; i++) {
1675                 struct dma_fence_chain *chain;
1676                 struct dma_fence *fence;
1677                 uint64_t point;
1678
1679                 fence = drm_syncobj_fence_get(syncobjs[i]);
1680                 chain = to_dma_fence_chain(fence);
1681                 if (chain) {
1682                         struct dma_fence *iter, *last_signaled =
1683                                 dma_fence_get(fence);
1684
1685                         if (args->flags &
1686                             DRM_SYNCOBJ_QUERY_FLAGS_LAST_SUBMITTED) {
1687                                 point = fence->seqno;
1688                         } else {
1689                                 dma_fence_chain_for_each(iter, fence) {
1690                                         if (iter->context != fence->context) {
1691                                                 dma_fence_put(iter);
1692                                                 /* It is most likely that timeline has
1693                                                 * unorder points. */
1694                                                 break;
1695                                         }
1696                                         dma_fence_put(last_signaled);
1697                                         last_signaled = dma_fence_get(iter);
1698                                 }
1699                                 point = dma_fence_is_signaled(last_signaled) ?
1700                                         last_signaled->seqno :
1701                                         to_dma_fence_chain(last_signaled)->prev_seqno;
1702                         }
1703                         dma_fence_put(last_signaled);
1704                 } else {
1705                         point = 0;
1706                 }
1707                 dma_fence_put(fence);
1708                 ret = copy_to_user(&points[i], &point, sizeof(uint64_t));
1709                 ret = ret ? -EFAULT : 0;
1710                 if (ret)
1711                         break;
1712         }
1713         drm_syncobj_array_free(syncobjs, args->count_handles);
1714
1715         return ret;
1716 }