root/drivers/gpu/drm/vmwgfx/vmwgfx_fence.c

DEFINITIONS

1. fman_from_fence
2. vmw_fence_obj_destroy
3. vmw_fence_get_driver_name
4. vmw_fence_get_timeline_name
5. vmw_fence_enable_signaling
6. vmwgfx_wait_cb
7. vmw_fence_wait
8. vmw_fence_work_func
9. vmw_fence_manager_init
10. vmw_fence_manager_takedown
11. vmw_fence_obj_init
12. vmw_fences_perform_actions
13. vmw_fence_goal_new_locked
14. vmw_fence_goal_check_locked
15. __vmw_fences_update
16. vmw_fences_update
17. vmw_fence_obj_signaled
18. vmw_fence_obj_wait
19. vmw_fence_obj_flush
20. vmw_fence_destroy
21. vmw_fence_create
22. vmw_user_fence_destroy
23. vmw_user_fence_base_release
24. vmw_user_fence_create
25. vmw_wait_dma_fence
26. vmw_fence_fifo_down
27. vmw_fence_fifo_up
28. vmw_fence_obj_lookup
29. vmw_fence_obj_wait_ioctl
30. vmw_fence_obj_signaled_ioctl
31. vmw_fence_obj_unref_ioctl
32. vmw_event_fence_action_seq_passed
33. vmw_event_fence_action_cleanup
34. vmw_fence_obj_add_action
35. vmw_event_fence_action_queue
36. vmw_event_fence_action_create
37. vmw_fence_event_ioctl

   1 // SPDX-License-Identifier: GPL-2.0 OR MIT
   2 /**************************************************************************
   3  *
   4  * Copyright 2011-2014 VMware, Inc., Palo Alto, CA., USA
   5  *
   6  * Permission is hereby granted, free of charge, to any person obtaining a
   7  * copy of this software and associated documentation files (the
   8  * "Software"), to deal in the Software without restriction, including
   9  * without limitation the rights to use, copy, modify, merge, publish,
  10  * distribute, sub license, and/or sell copies of the Software, and to
  11  * permit persons to whom the Software is furnished to do so, subject to
  12  * the following conditions:
  13  *
  14  * The above copyright notice and this permission notice (including the
  15  * next paragraph) shall be included in all copies or substantial portions
  16  * of the Software.
  17  *
  18  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
  19  * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
  20  * FITNESS FOR A PARTICULAR PURPOSE AND NON-INFRINGEMENT. IN NO EVENT SHALL
  21  * THE COPYRIGHT HOLDERS, AUTHORS AND/OR ITS SUPPLIERS BE LIABLE FOR ANY CLAIM,
  22  * DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR
  23  * OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE
  24  * USE OR OTHER DEALINGS IN THE SOFTWARE.
  25  *
  26  **************************************************************************/
  27 
  28 #include <linux/sched/signal.h>
  29 
  30 #include "vmwgfx_drv.h"
  31 
  32 #define VMW_FENCE_WRAP (1 << 31)
  33 
  34 struct vmw_fence_manager {
  35         int num_fence_objects;
  36         struct vmw_private *dev_priv;
  37         spinlock_t lock;
  38         struct list_head fence_list;
  39         struct work_struct work;
  40         u32 user_fence_size;
  41         u32 fence_size;
  42         u32 event_fence_action_size;
  43         bool fifo_down;
  44         struct list_head cleanup_list;
  45         uint32_t pending_actions[VMW_ACTION_MAX];
  46         struct mutex goal_irq_mutex;
  47         bool goal_irq_on; /* Protected by @goal_irq_mutex */
  48         bool seqno_valid; /* Protected by @lock, and may not be set to true
  49                              without the @goal_irq_mutex held. */
  50         u64 ctx;
  51 };
  52 
  53 struct vmw_user_fence {
  54         struct ttm_base_object base;
  55         struct vmw_fence_obj fence;
  56 };
  57 
  58 /**
  59  * struct vmw_event_fence_action - fence action that delivers a drm event.
  60  *
  61  * @e: A struct drm_pending_event that controls the event delivery.
  62  * @action: A struct vmw_fence_action to hook up to a fence.
  63  * @fence: A referenced pointer to the fence to keep it alive while @action
  64  * hangs on it.
  65  * @dev: Pointer to a struct drm_device so we can access the event stuff.
  66  * @kref: Both @e and @action has destructors, so we need to refcount.
  67  * @size: Size accounted for this object.
  68  * @tv_sec: If non-null, the variable pointed to will be assigned
  69  * current time tv_sec val when the fence signals.
  70  * @tv_usec: Must be set if @tv_sec is set, and the variable pointed to will
  71  * be assigned the current time tv_usec val when the fence signals.
  72  */
  73 struct vmw_event_fence_action {
  74         struct vmw_fence_action action;
  75 
  76         struct drm_pending_event *event;
  77         struct vmw_fence_obj *fence;
  78         struct drm_device *dev;
  79 
  80         uint32_t *tv_sec;
  81         uint32_t *tv_usec;
  82 };
  83 
  84 static struct vmw_fence_manager *
  85 fman_from_fence(struct vmw_fence_obj *fence)
  86 {
  87         return container_of(fence->base.lock, struct vmw_fence_manager, lock);
  88 }
  89 
  90 /**
  91  * Note on fencing subsystem usage of irqs:
  92  * Typically the vmw_fences_update function is called
  93  *
  94  * a) When a new fence seqno has been submitted by the fifo code.
  95  * b) On-demand when we have waiters. Sleeping waiters will switch on the
  96  * ANY_FENCE irq and call vmw_fences_update function each time an ANY_FENCE
  97  * irq is received. When the last fence waiter is gone, that IRQ is masked
  98  * away.
  99  *
 100  * In situations where there are no waiters and we don't submit any new fences,
 101  * fence objects may not be signaled. This is perfectly OK, since there are
 102  * no consumers of the signaled data, but that is NOT ok when there are fence
 103  * actions attached to a fence. The fencing subsystem then makes use of the
 104  * FENCE_GOAL irq and sets the fence goal seqno to that of the next fence
 105  * which has an action attached, and each time vmw_fences_update is called,
 106  * the subsystem makes sure the fence goal seqno is updated.
 107  *
 108  * The fence goal seqno irq is on as long as there are unsignaled fence
 109  * objects with actions attached to them.
 110  */
 111 
 112 static void vmw_fence_obj_destroy(struct dma_fence *f)
 113 {
 114         struct vmw_fence_obj *fence =
 115                 container_of(f, struct vmw_fence_obj, base);
 116 
 117         struct vmw_fence_manager *fman = fman_from_fence(fence);
 118 
 119         spin_lock(&fman->lock);
 120         list_del_init(&fence->head);
 121         --fman->num_fence_objects;
 122         spin_unlock(&fman->lock);
 123         fence->destroy(fence);
 124 }
 125 
 126 static const char *vmw_fence_get_driver_name(struct dma_fence *f)
 127 {
 128         return "vmwgfx";
 129 }
 130 
 131 static const char *vmw_fence_get_timeline_name(struct dma_fence *f)
 132 {
 133         return "svga";
 134 }
 135 
 136 static bool vmw_fence_enable_signaling(struct dma_fence *f)
 137 {
 138         struct vmw_fence_obj *fence =
 139                 container_of(f, struct vmw_fence_obj, base);
 140 
 141         struct vmw_fence_manager *fman = fman_from_fence(fence);
 142         struct vmw_private *dev_priv = fman->dev_priv;
 143 
 144         u32 *fifo_mem = dev_priv->mmio_virt;
 145         u32 seqno = vmw_mmio_read(fifo_mem + SVGA_FIFO_FENCE);
 146         if (seqno - fence->base.seqno < VMW_FENCE_WRAP)
 147                 return false;
 148 
 149         vmw_fifo_ping_host(dev_priv, SVGA_SYNC_GENERIC);
 150 
 151         return true;
 152 }
 153 
 154 struct vmwgfx_wait_cb {
 155         struct dma_fence_cb base;
 156         struct task_struct *task;
 157 };
 158 
 159 static void
 160 vmwgfx_wait_cb(struct dma_fence *fence, struct dma_fence_cb *cb)
 161 {
 162         struct vmwgfx_wait_cb *wait =
 163                 container_of(cb, struct vmwgfx_wait_cb, base);
 164 
 165         wake_up_process(wait->task);
 166 }
 167 
 168 static void __vmw_fences_update(struct vmw_fence_manager *fman);
 169 
 170 static long vmw_fence_wait(struct dma_fence *f, bool intr, signed long timeout)
 171 {
 172         struct vmw_fence_obj *fence =
 173                 container_of(f, struct vmw_fence_obj, base);
 174 
 175         struct vmw_fence_manager *fman = fman_from_fence(fence);
 176         struct vmw_private *dev_priv = fman->dev_priv;
 177         struct vmwgfx_wait_cb cb;
 178         long ret = timeout;
 179 
 180         if (likely(vmw_fence_obj_signaled(fence)))
 181                 return timeout;
 182 
 183         vmw_fifo_ping_host(dev_priv, SVGA_SYNC_GENERIC);
 184         vmw_seqno_waiter_add(dev_priv);
 185 
 186         spin_lock(f->lock);
 187 
 188         if (test_bit(DMA_FENCE_FLAG_SIGNALED_BIT, &f->flags))
 189                 goto out;
 190 
 191         if (intr && signal_pending(current)) {
 192                 ret = -ERESTARTSYS;
 193                 goto out;
 194         }
 195 
 196         cb.base.func = vmwgfx_wait_cb;
 197         cb.task = current;
 198         list_add(&cb.base.node, &f->cb_list);
 199 
 200         for (;;) {
 201                 __vmw_fences_update(fman);
 202 
 203                 /*
 204                  * We can use the barrier free __set_current_state() since
 205                  * DMA_FENCE_FLAG_SIGNALED_BIT + wakeup is protected by the
 206                  * fence spinlock.
 207                  */
 208                 if (intr)
 209                         __set_current_state(TASK_INTERRUPTIBLE);
 210                 else
 211                         __set_current_state(TASK_UNINTERRUPTIBLE);
 212 
 213                 if (test_bit(DMA_FENCE_FLAG_SIGNALED_BIT, &f->flags)) {
 214                         if (ret == 0 && timeout > 0)
 215                                 ret = 1;
 216                         break;
 217                 }
 218 
 219                 if (intr && signal_pending(current)) {
 220                         ret = -ERESTARTSYS;
 221                         break;
 222                 }
 223 
 224                 if (ret == 0)
 225                         break;
 226 
 227                 spin_unlock(f->lock);
 228 
 229                 ret = schedule_timeout(ret);
 230 
 231                 spin_lock(f->lock);
 232         }
 233         __set_current_state(TASK_RUNNING);
 234         if (!list_empty(&cb.base.node))
 235                 list_del(&cb.base.node);
 236 
 237 out:
 238         spin_unlock(f->lock);
 239 
 240         vmw_seqno_waiter_remove(dev_priv);
 241 
 242         return ret;
 243 }
 244 
 245 static const struct dma_fence_ops vmw_fence_ops = {
 246         .get_driver_name = vmw_fence_get_driver_name,
 247         .get_timeline_name = vmw_fence_get_timeline_name,
 248         .enable_signaling = vmw_fence_enable_signaling,
 249         .wait = vmw_fence_wait,
 250         .release = vmw_fence_obj_destroy,
 251 };
 252 
 253 
 254 /**
 255  * Execute signal actions on fences recently signaled.
 256  * This is done from a workqueue so we don't have to execute
 257  * signal actions from atomic context.
 258  */
 259 
 260 static void vmw_fence_work_func(struct work_struct *work)
 261 {
 262         struct vmw_fence_manager *fman =
 263                 container_of(work, struct vmw_fence_manager, work);
 264         struct list_head list;
 265         struct vmw_fence_action *action, *next_action;
 266         bool seqno_valid;
 267 
 268         do {
 269                 INIT_LIST_HEAD(&list);
 270                 mutex_lock(&fman->goal_irq_mutex);
 271 
 272                 spin_lock(&fman->lock);
 273                 list_splice_init(&fman->cleanup_list, &list);
 274                 seqno_valid = fman->seqno_valid;
 275                 spin_unlock(&fman->lock);
 276 
 277                 if (!seqno_valid && fman->goal_irq_on) {
 278                         fman->goal_irq_on = false;
 279                         vmw_goal_waiter_remove(fman->dev_priv);
 280                 }
 281                 mutex_unlock(&fman->goal_irq_mutex);
 282 
 283                 if (list_empty(&list))
 284                         return;
 285 
 286                 /*
 287                  * At this point, only we should be able to manipulate the
 288                  * list heads of the actions we have on the private list.
 289                  * hence fman::lock not held.
 290                  */
 291 
 292                 list_for_each_entry_safe(action, next_action, &list, head) {
 293                         list_del_init(&action->head);
 294                         if (action->cleanup)
 295                                 action->cleanup(action);
 296                 }
 297         } while (1);
 298 }
 299 
 300 struct vmw_fence_manager *vmw_fence_manager_init(struct vmw_private *dev_priv)
 301 {
 302         struct vmw_fence_manager *fman = kzalloc(sizeof(*fman), GFP_KERNEL);
 303 
 304         if (unlikely(!fman))
 305                 return NULL;
 306 
 307         fman->dev_priv = dev_priv;
 308         spin_lock_init(&fman->lock);
 309         INIT_LIST_HEAD(&fman->fence_list);
 310         INIT_LIST_HEAD(&fman->cleanup_list);
 311         INIT_WORK(&fman->work, &vmw_fence_work_func);
 312         fman->fifo_down = true;
 313         fman->user_fence_size = ttm_round_pot(sizeof(struct vmw_user_fence)) +
 314                 TTM_OBJ_EXTRA_SIZE;
 315         fman->fence_size = ttm_round_pot(sizeof(struct vmw_fence_obj));
 316         fman->event_fence_action_size =
 317                 ttm_round_pot(sizeof(struct vmw_event_fence_action));
 318         mutex_init(&fman->goal_irq_mutex);
 319         fman->ctx = dma_fence_context_alloc(1);
 320 
 321         return fman;
 322 }
 323 
 324 void vmw_fence_manager_takedown(struct vmw_fence_manager *fman)
 325 {
 326         bool lists_empty;
 327 
 328         (void) cancel_work_sync(&fman->work);
 329 
 330         spin_lock(&fman->lock);
 331         lists_empty = list_empty(&fman->fence_list) &&
 332                 list_empty(&fman->cleanup_list);
 333         spin_unlock(&fman->lock);
 334 
 335         BUG_ON(!lists_empty);
 336         kfree(fman);
 337 }
 338 
 339 static int vmw_fence_obj_init(struct vmw_fence_manager *fman,
 340                               struct vmw_fence_obj *fence, u32 seqno,
 341                               void (*destroy) (struct vmw_fence_obj *fence))
 342 {
 343         int ret = 0;
 344 
 345         dma_fence_init(&fence->base, &vmw_fence_ops, &fman->lock,
 346                        fman->ctx, seqno);
 347         INIT_LIST_HEAD(&fence->seq_passed_actions);
 348         fence->destroy = destroy;
 349 
 350         spin_lock(&fman->lock);
 351         if (unlikely(fman->fifo_down)) {
 352                 ret = -EBUSY;
 353                 goto out_unlock;
 354         }
 355         list_add_tail(&fence->head, &fman->fence_list);
 356         ++fman->num_fence_objects;
 357 
 358 out_unlock:
 359         spin_unlock(&fman->lock);
 360         return ret;
 361 
 362 }
 363 
 364 static void vmw_fences_perform_actions(struct vmw_fence_manager *fman,
 365                                 struct list_head *list)
 366 {
 367         struct vmw_fence_action *action, *next_action;
 368 
 369         list_for_each_entry_safe(action, next_action, list, head) {
 370                 list_del_init(&action->head);
 371                 fman->pending_actions[action->type]--;
 372                 if (action->seq_passed != NULL)
 373                         action->seq_passed(action);
 374 
 375                 /*
 376                  * Add the cleanup action to the cleanup list so that
 377                  * it will be performed by a worker task.
 378                  */
 379 
 380                 list_add_tail(&action->head, &fman->cleanup_list);
 381         }
 382 }
 383 
 384 /**
 385  * vmw_fence_goal_new_locked - Figure out a new device fence goal
 386  * seqno if needed.
 387  *
 388  * @fman: Pointer to a fence manager.
 389  * @passed_seqno: The seqno the device currently signals as passed.
 390  *
 391  * This function should be called with the fence manager lock held.
 392  * It is typically called when we have a new passed_seqno, and
 393  * we might need to update the fence goal. It checks to see whether
 394  * the current fence goal has already passed, and, in that case,
 395  * scans through all unsignaled fences to get the next fence object with an
 396  * action attached, and sets the seqno of that fence as a new fence goal.
 397  *
 398  * returns true if the device goal seqno was updated. False otherwise.
 399  */
 400 static bool vmw_fence_goal_new_locked(struct vmw_fence_manager *fman,
 401                                       u32 passed_seqno)
 402 {
 403         u32 goal_seqno;
 404         u32 *fifo_mem;
 405         struct vmw_fence_obj *fence;
 406 
 407         if (likely(!fman->seqno_valid))
 408                 return false;
 409 
 410         fifo_mem = fman->dev_priv->mmio_virt;
 411         goal_seqno = vmw_mmio_read(fifo_mem + SVGA_FIFO_FENCE_GOAL);
 412         if (likely(passed_seqno - goal_seqno >= VMW_FENCE_WRAP))
 413                 return false;
 414 
 415         fman->seqno_valid = false;
 416         list_for_each_entry(fence, &fman->fence_list, head) {
 417                 if (!list_empty(&fence->seq_passed_actions)) {
 418                         fman->seqno_valid = true;
 419                         vmw_mmio_write(fence->base.seqno,
 420                                        fifo_mem + SVGA_FIFO_FENCE_GOAL);
 421                         break;
 422                 }
 423         }
 424 
 425         return true;
 426 }
 427 
 428 
 429 /**
 430  * vmw_fence_goal_check_locked - Replace the device fence goal seqno if
 431  * needed.
 432  *
 433  * @fence: Pointer to a struct vmw_fence_obj the seqno of which should be
 434  * considered as a device fence goal.
 435  *
 436  * This function should be called with the fence manager lock held.
 437  * It is typically called when an action has been attached to a fence to
 438  * check whether the seqno of that fence should be used for a fence
 439  * goal interrupt. This is typically needed if the current fence goal is
 440  * invalid, or has a higher seqno than that of the current fence object.
 441  *
 442  * returns true if the device goal seqno was updated. False otherwise.
 443  */
 444 static bool vmw_fence_goal_check_locked(struct vmw_fence_obj *fence)
 445 {
 446         struct vmw_fence_manager *fman = fman_from_fence(fence);
 447         u32 goal_seqno;
 448         u32 *fifo_mem;
 449 
 450         if (dma_fence_is_signaled_locked(&fence->base))
 451                 return false;
 452 
 453         fifo_mem = fman->dev_priv->mmio_virt;
 454         goal_seqno = vmw_mmio_read(fifo_mem + SVGA_FIFO_FENCE_GOAL);
 455         if (likely(fman->seqno_valid &&
 456                    goal_seqno - fence->base.seqno < VMW_FENCE_WRAP))
 457                 return false;
 458 
 459         vmw_mmio_write(fence->base.seqno, fifo_mem + SVGA_FIFO_FENCE_GOAL);
 460         fman->seqno_valid = true;
 461 
 462         return true;
 463 }
 464 
 465 static void __vmw_fences_update(struct vmw_fence_manager *fman)
 466 {
 467         struct vmw_fence_obj *fence, *next_fence;
 468         struct list_head action_list;
 469         bool needs_rerun;
 470         uint32_t seqno, new_seqno;
 471         u32 *fifo_mem = fman->dev_priv->mmio_virt;
 472 
 473         seqno = vmw_mmio_read(fifo_mem + SVGA_FIFO_FENCE);
 474 rerun:
 475         list_for_each_entry_safe(fence, next_fence, &fman->fence_list, head) {
 476                 if (seqno - fence->base.seqno < VMW_FENCE_WRAP) {
 477                         list_del_init(&fence->head);
 478                         dma_fence_signal_locked(&fence->base);
 479                         INIT_LIST_HEAD(&action_list);
 480                         list_splice_init(&fence->seq_passed_actions,
 481                                          &action_list);
 482                         vmw_fences_perform_actions(fman, &action_list);
 483                 } else
 484                         break;
 485         }
 486 
 487         /*
 488          * Rerun if the fence goal seqno was updated, and the
 489          * hardware might have raced with that update, so that
 490          * we missed a fence_goal irq.
 491          */
 492 
 493         needs_rerun = vmw_fence_goal_new_locked(fman, seqno);
 494         if (unlikely(needs_rerun)) {
 495                 new_seqno = vmw_mmio_read(fifo_mem + SVGA_FIFO_FENCE);
 496                 if (new_seqno != seqno) {
 497                         seqno = new_seqno;
 498                         goto rerun;
 499                 }
 500         }
 501 
 502         if (!list_empty(&fman->cleanup_list))
 503                 (void) schedule_work(&fman->work);
 504 }
 505 
 506 void vmw_fences_update(struct vmw_fence_manager *fman)
 507 {
 508         spin_lock(&fman->lock);
 509         __vmw_fences_update(fman);
 510         spin_unlock(&fman->lock);
 511 }
 512 
 513 bool vmw_fence_obj_signaled(struct vmw_fence_obj *fence)
 514 {
 515         struct vmw_fence_manager *fman = fman_from_fence(fence);
 516 
 517         if (test_bit(DMA_FENCE_FLAG_SIGNALED_BIT, &fence->base.flags))
 518                 return 1;
 519 
 520         vmw_fences_update(fman);
 521 
 522         return dma_fence_is_signaled(&fence->base);
 523 }
 524 
 525 int vmw_fence_obj_wait(struct vmw_fence_obj *fence, bool lazy,
 526                        bool interruptible, unsigned long timeout)
 527 {
 528         long ret = dma_fence_wait_timeout(&fence->base, interruptible, timeout);
 529 
 530         if (likely(ret > 0))
 531                 return 0;
 532         else if (ret == 0)
 533                 return -EBUSY;
 534         else
 535                 return ret;
 536 }
 537 
 538 void vmw_fence_obj_flush(struct vmw_fence_obj *fence)
 539 {
 540         struct vmw_private *dev_priv = fman_from_fence(fence)->dev_priv;
 541 
 542         vmw_fifo_ping_host(dev_priv, SVGA_SYNC_GENERIC);
 543 }
 544 
 545 static void vmw_fence_destroy(struct vmw_fence_obj *fence)
 546 {
 547         dma_fence_free(&fence->base);
 548 }
 549 
 550 int vmw_fence_create(struct vmw_fence_manager *fman,
 551                      uint32_t seqno,
 552                      struct vmw_fence_obj **p_fence)
 553 {
 554         struct vmw_fence_obj *fence;
 555         int ret;
 556 
 557         fence = kzalloc(sizeof(*fence), GFP_KERNEL);
 558         if (unlikely(!fence))
 559                 return -ENOMEM;
 560 
 561         ret = vmw_fence_obj_init(fman, fence, seqno,
 562                                  vmw_fence_destroy);
 563         if (unlikely(ret != 0))
 564                 goto out_err_init;
 565 
 566         *p_fence = fence;
 567         return 0;
 568 
 569 out_err_init:
 570         kfree(fence);
 571         return ret;
 572 }
 573 
 574 
 575 static void vmw_user_fence_destroy(struct vmw_fence_obj *fence)
 576 {
 577         struct vmw_user_fence *ufence =
 578                 container_of(fence, struct vmw_user_fence, fence);
 579         struct vmw_fence_manager *fman = fman_from_fence(fence);
 580 
 581         ttm_base_object_kfree(ufence, base);
 582         /*
 583          * Free kernel space accounting.
 584          */
 585         ttm_mem_global_free(vmw_mem_glob(fman->dev_priv),
 586                             fman->user_fence_size);
 587 }
 588 
 589 static void vmw_user_fence_base_release(struct ttm_base_object **p_base)
 590 {
 591         struct ttm_base_object *base = *p_base;
 592         struct vmw_user_fence *ufence =
 593                 container_of(base, struct vmw_user_fence, base);
 594         struct vmw_fence_obj *fence = &ufence->fence;
 595 
 596         *p_base = NULL;
 597         vmw_fence_obj_unreference(&fence);
 598 }
 599 
 600 int vmw_user_fence_create(struct drm_file *file_priv,
 601                           struct vmw_fence_manager *fman,
 602                           uint32_t seqno,
 603                           struct vmw_fence_obj **p_fence,
 604                           uint32_t *p_handle)
 605 {
 606         struct ttm_object_file *tfile = vmw_fpriv(file_priv)->tfile;
 607         struct vmw_user_fence *ufence;
 608         struct vmw_fence_obj *tmp;
 609         struct ttm_mem_global *mem_glob = vmw_mem_glob(fman->dev_priv);
 610         struct ttm_operation_ctx ctx = {
 611                 .interruptible = false,
 612                 .no_wait_gpu = false
 613         };
 614         int ret;
 615 
 616         /*
 617          * Kernel memory space accounting, since this object may
 618          * be created by a user-space request.
 619          */
 620 
 621         ret = ttm_mem_global_alloc(mem_glob, fman->user_fence_size,
 622                                    &ctx);
 623         if (unlikely(ret != 0))
 624                 return ret;
 625 
 626         ufence = kzalloc(sizeof(*ufence), GFP_KERNEL);
 627         if (unlikely(!ufence)) {
 628                 ret = -ENOMEM;
 629                 goto out_no_object;
 630         }
 631 
 632         ret = vmw_fence_obj_init(fman, &ufence->fence, seqno,
 633                                  vmw_user_fence_destroy);
 634         if (unlikely(ret != 0)) {
 635                 kfree(ufence);
 636                 goto out_no_object;
 637         }
 638 
 639         /*
 640          * The base object holds a reference which is freed in
 641          * vmw_user_fence_base_release.
 642          */
 643         tmp = vmw_fence_obj_reference(&ufence->fence);
 644         ret = ttm_base_object_init(tfile, &ufence->base, false,
 645                                    VMW_RES_FENCE,
 646                                    &vmw_user_fence_base_release, NULL);
 647 
 648 
 649         if (unlikely(ret != 0)) {
 650                 /*
 651                  * Free the base object's reference
 652                  */
 653                 vmw_fence_obj_unreference(&tmp);
 654                 goto out_err;
 655         }
 656 
 657         *p_fence = &ufence->fence;
 658         *p_handle = ufence->base.handle;
 659 
 660         return 0;
 661 out_err:
 662         tmp = &ufence->fence;
 663         vmw_fence_obj_unreference(&tmp);
 664 out_no_object:
 665         ttm_mem_global_free(mem_glob, fman->user_fence_size);
 666         return ret;
 667 }
 668 
 669 
 670 /**
 671  * vmw_wait_dma_fence - Wait for a dma fence
 672  *
 673  * @fman: pointer to a fence manager
 674  * @fence: DMA fence to wait on
 675  *
 676  * This function handles the case when the fence is actually a fence
 677  * array.  If that's the case, it'll wait on each of the child fence
 678  */
 679 int vmw_wait_dma_fence(struct vmw_fence_manager *fman,
 680                        struct dma_fence *fence)
 681 {
 682         struct dma_fence_array *fence_array;
 683         int ret = 0;
 684         int i;
 685 
 686 
 687         if (dma_fence_is_signaled(fence))
 688                 return 0;
 689 
 690         if (!dma_fence_is_array(fence))
 691                 return dma_fence_wait(fence, true);
 692 
 693         /* From i915: Note that if the fence-array was created in
 694          * signal-on-any mode, we should *not* decompose it into its individual
 695          * fences. However, we don't currently store which mode the fence-array
 696          * is operating in. Fortunately, the only user of signal-on-any is
 697          * private to amdgpu and we should not see any incoming fence-array
 698          * from sync-file being in signal-on-any mode.
 699          */
 700 
 701         fence_array = to_dma_fence_array(fence);
 702         for (i = 0; i < fence_array->num_fences; i++) {
 703                 struct dma_fence *child = fence_array->fences[i];
 704 
 705                 ret = dma_fence_wait(child, true);
 706 
 707                 if (ret < 0)
 708                         return ret;
 709         }
 710 
 711         return 0;
 712 }
 713 
 714 
 715 /**
 716  * vmw_fence_fifo_down - signal all unsignaled fence objects.
 717  */
 718 
 719 void vmw_fence_fifo_down(struct vmw_fence_manager *fman)
 720 {
 721         struct list_head action_list;
 722         int ret;
 723 
 724         /*
 725          * The list may be altered while we traverse it, so always
 726          * restart when we've released the fman->lock.
 727          */
 728 
 729         spin_lock(&fman->lock);
 730         fman->fifo_down = true;
 731         while (!list_empty(&fman->fence_list)) {
 732                 struct vmw_fence_obj *fence =
 733                         list_entry(fman->fence_list.prev, struct vmw_fence_obj,
 734                                    head);
 735                 dma_fence_get(&fence->base);
 736                 spin_unlock(&fman->lock);
 737 
 738                 ret = vmw_fence_obj_wait(fence, false, false,
 739                                          VMW_FENCE_WAIT_TIMEOUT);
 740 
 741                 if (unlikely(ret != 0)) {
 742                         list_del_init(&fence->head);
 743                         dma_fence_signal(&fence->base);
 744                         INIT_LIST_HEAD(&action_list);
 745                         list_splice_init(&fence->seq_passed_actions,
 746                                          &action_list);
 747                         vmw_fences_perform_actions(fman, &action_list);
 748                 }
 749 
 750                 BUG_ON(!list_empty(&fence->head));
 751                 dma_fence_put(&fence->base);
 752                 spin_lock(&fman->lock);
 753         }
 754         spin_unlock(&fman->lock);
 755 }
 756 
 757 void vmw_fence_fifo_up(struct vmw_fence_manager *fman)
 758 {
 759         spin_lock(&fman->lock);
 760         fman->fifo_down = false;
 761         spin_unlock(&fman->lock);
 762 }
 763 
 764 
 765 /**
 766  * vmw_fence_obj_lookup - Look up a user-space fence object
 767  *
 768  * @tfile: A struct ttm_object_file identifying the caller.
 769  * @handle: A handle identifying the fence object.
 770  * @return: A struct vmw_user_fence base ttm object on success or
 771  * an error pointer on failure.
 772  *
 773  * The fence object is looked up and type-checked. The caller needs
 774  * to have opened the fence object first, but since that happens on
 775  * creation and fence objects aren't shareable, that's not an
 776  * issue currently.
 777  */
 778 static struct ttm_base_object *
 779 vmw_fence_obj_lookup(struct ttm_object_file *tfile, u32 handle)
 780 {
 781         struct ttm_base_object *base = ttm_base_object_lookup(tfile, handle);
 782 
 783         if (!base) {
 784                 pr_err("Invalid fence object handle 0x%08lx.\n",
 785                        (unsigned long)handle);
 786                 return ERR_PTR(-EINVAL);
 787         }
 788 
 789         if (base->refcount_release != vmw_user_fence_base_release) {
 790                 pr_err("Invalid fence object handle 0x%08lx.\n",
 791                        (unsigned long)handle);
 792                 ttm_base_object_unref(&base);
 793                 return ERR_PTR(-EINVAL);
 794         }
 795 
 796         return base;
 797 }
 798 
 799 
 800 int vmw_fence_obj_wait_ioctl(struct drm_device *dev, void *data,
 801                              struct drm_file *file_priv)
 802 {
 803         struct drm_vmw_fence_wait_arg *arg =
 804             (struct drm_vmw_fence_wait_arg *)data;
 805         unsigned long timeout;
 806         struct ttm_base_object *base;
 807         struct vmw_fence_obj *fence;
 808         struct ttm_object_file *tfile = vmw_fpriv(file_priv)->tfile;
 809         int ret;
 810         uint64_t wait_timeout = ((uint64_t)arg->timeout_us * HZ);
 811 
 812         /*
 813          * 64-bit division not present on 32-bit systems, so do an
 814          * approximation. (Divide by 1000000).
 815          */
 816 
 817         wait_timeout = (wait_timeout >> 20) + (wait_timeout >> 24) -
 818           (wait_timeout >> 26);
 819 
 820         if (!arg->cookie_valid) {
 821                 arg->cookie_valid = 1;
 822                 arg->kernel_cookie = jiffies + wait_timeout;
 823         }
 824 
 825         base = vmw_fence_obj_lookup(tfile, arg->handle);
 826         if (IS_ERR(base))
 827                 return PTR_ERR(base);
 828 
 829         fence = &(container_of(base, struct vmw_user_fence, base)->fence);
 830 
 831         timeout = jiffies;
 832         if (time_after_eq(timeout, (unsigned long)arg->kernel_cookie)) {
 833                 ret = ((vmw_fence_obj_signaled(fence)) ?
 834                        0 : -EBUSY);
 835                 goto out;
 836         }
 837 
 838         timeout = (unsigned long)arg->kernel_cookie - timeout;
 839 
 840         ret = vmw_fence_obj_wait(fence, arg->lazy, true, timeout);
 841 
 842 out:
 843         ttm_base_object_unref(&base);
 844 
 845         /*
 846          * Optionally unref the fence object.
 847          */
 848 
 849         if (ret == 0 && (arg->wait_options & DRM_VMW_WAIT_OPTION_UNREF))
 850                 return ttm_ref_object_base_unref(tfile, arg->handle,
 851                                                  TTM_REF_USAGE);
 852         return ret;
 853 }
 854 
 855 int vmw_fence_obj_signaled_ioctl(struct drm_device *dev, void *data,
 856                                  struct drm_file *file_priv)
 857 {
 858         struct drm_vmw_fence_signaled_arg *arg =
 859                 (struct drm_vmw_fence_signaled_arg *) data;
 860         struct ttm_base_object *base;
 861         struct vmw_fence_obj *fence;
 862         struct vmw_fence_manager *fman;
 863         struct ttm_object_file *tfile = vmw_fpriv(file_priv)->tfile;
 864         struct vmw_private *dev_priv = vmw_priv(dev);
 865 
 866         base = vmw_fence_obj_lookup(tfile, arg->handle);
 867         if (IS_ERR(base))
 868                 return PTR_ERR(base);
 869 
 870         fence = &(container_of(base, struct vmw_user_fence, base)->fence);
 871         fman = fman_from_fence(fence);
 872 
 873         arg->signaled = vmw_fence_obj_signaled(fence);
 874 
 875         arg->signaled_flags = arg->flags;
 876         spin_lock(&fman->lock);
 877         arg->passed_seqno = dev_priv->last_read_seqno;
 878         spin_unlock(&fman->lock);
 879 
 880         ttm_base_object_unref(&base);
 881 
 882         return 0;
 883 }
 884 
 885 
 886 int vmw_fence_obj_unref_ioctl(struct drm_device *dev, void *data,
 887                               struct drm_file *file_priv)
 888 {
 889         struct drm_vmw_fence_arg *arg =
 890                 (struct drm_vmw_fence_arg *) data;
 891 
 892         return ttm_ref_object_base_unref(vmw_fpriv(file_priv)->tfile,
 893                                          arg->handle,
 894                                          TTM_REF_USAGE);
 895 }
 896 
 897 /**
 898  * vmw_event_fence_action_seq_passed
 899  *
 900  * @action: The struct vmw_fence_action embedded in a struct
 901  * vmw_event_fence_action.
 902  *
 903  * This function is called when the seqno of the fence where @action is
 904  * attached has passed. It queues the event on the submitter's event list.
 905  * This function is always called from atomic context.
 906  */
 907 static void vmw_event_fence_action_seq_passed(struct vmw_fence_action *action)
 908 {
 909         struct vmw_event_fence_action *eaction =
 910                 container_of(action, struct vmw_event_fence_action, action);
 911         struct drm_device *dev = eaction->dev;
 912         struct drm_pending_event *event = eaction->event;
 913 
 914         if (unlikely(event == NULL))
 915                 return;
 916 
 917         spin_lock_irq(&dev->event_lock);
 918 
 919         if (likely(eaction->tv_sec != NULL)) {
 920                 struct timespec64 ts;
 921 
 922                 ktime_get_ts64(&ts);
 923                 /* monotonic time, so no y2038 overflow */
 924                 *eaction->tv_sec = ts.tv_sec;
 925                 *eaction->tv_usec = ts.tv_nsec / NSEC_PER_USEC;
 926         }
 927 
 928         drm_send_event_locked(dev, eaction->event);
 929         eaction->event = NULL;
 930         spin_unlock_irq(&dev->event_lock);
 931 }
 932 
 933 /**
 934  * vmw_event_fence_action_cleanup
 935  *
 936  * @action: The struct vmw_fence_action embedded in a struct
 937  * vmw_event_fence_action.
 938  *
 939  * This function is the struct vmw_fence_action destructor. It's typically
 940  * called from a workqueue.
 941  */
 942 static void vmw_event_fence_action_cleanup(struct vmw_fence_action *action)
 943 {
 944         struct vmw_event_fence_action *eaction =
 945                 container_of(action, struct vmw_event_fence_action, action);
 946 
 947         vmw_fence_obj_unreference(&eaction->fence);
 948         kfree(eaction);
 949 }
 950 
 951 
 952 /**
 953  * vmw_fence_obj_add_action - Add an action to a fence object.
 954  *
 955  * @fence - The fence object.
 956  * @action - The action to add.
 957  *
 958  * Note that the action callbacks may be executed before this function
 959  * returns.
 960  */
 961 static void vmw_fence_obj_add_action(struct vmw_fence_obj *fence,
 962                               struct vmw_fence_action *action)
 963 {
 964         struct vmw_fence_manager *fman = fman_from_fence(fence);
 965         bool run_update = false;
 966 
 967         mutex_lock(&fman->goal_irq_mutex);
 968         spin_lock(&fman->lock);
 969 
 970         fman->pending_actions[action->type]++;
 971         if (dma_fence_is_signaled_locked(&fence->base)) {
 972                 struct list_head action_list;
 973 
 974                 INIT_LIST_HEAD(&action_list);
 975                 list_add_tail(&action->head, &action_list);
 976                 vmw_fences_perform_actions(fman, &action_list);
 977         } else {
 978                 list_add_tail(&action->head, &fence->seq_passed_actions);
 979 
 980                 /*
 981                  * This function may set fman::seqno_valid, so it must
 982                  * be run with the goal_irq_mutex held.
 983                  */
 984                 run_update = vmw_fence_goal_check_locked(fence);
 985         }
 986 
 987         spin_unlock(&fman->lock);
 988 
 989         if (run_update) {
 990                 if (!fman->goal_irq_on) {
 991                         fman->goal_irq_on = true;
 992                         vmw_goal_waiter_add(fman->dev_priv);
 993                 }
 994                 vmw_fences_update(fman);
 995         }
 996         mutex_unlock(&fman->goal_irq_mutex);
 997 
 998 }
 999 
1000 /**
1001  * vmw_event_fence_action_create - Post an event for sending when a fence
1002  * object seqno has passed.
1003  *
1004  * @file_priv: The file connection on which the event should be posted.
1005  * @fence: The fence object on which to post the event.
1006  * @event: Event to be posted. This event should've been alloced
1007  * using k[mz]alloc, and should've been completely initialized.
1008  * @interruptible: Interruptible waits if possible.
1009  *
1010  * As a side effect, the object pointed to by @event may have been
1011  * freed when this function returns. If this function returns with
1012  * an error code, the caller needs to free that object.
1013  */
1014 
1015 int vmw_event_fence_action_queue(struct drm_file *file_priv,
1016                                  struct vmw_fence_obj *fence,
1017                                  struct drm_pending_event *event,
1018                                  uint32_t *tv_sec,
1019                                  uint32_t *tv_usec,
1020                                  bool interruptible)
1021 {
1022         struct vmw_event_fence_action *eaction;
1023         struct vmw_fence_manager *fman = fman_from_fence(fence);
1024 
1025         eaction = kzalloc(sizeof(*eaction), GFP_KERNEL);
1026         if (unlikely(!eaction))
1027                 return -ENOMEM;
1028 
1029         eaction->event = event;
1030 
1031         eaction->action.seq_passed = vmw_event_fence_action_seq_passed;
1032         eaction->action.cleanup = vmw_event_fence_action_cleanup;
1033         eaction->action.type = VMW_ACTION_EVENT;
1034 
1035         eaction->fence = vmw_fence_obj_reference(fence);
1036         eaction->dev = fman->dev_priv->dev;
1037         eaction->tv_sec = tv_sec;
1038         eaction->tv_usec = tv_usec;
1039 
1040         vmw_fence_obj_add_action(fence, &eaction->action);
1041 
1042         return 0;
1043 }
1044 
1045 struct vmw_event_fence_pending {
1046         struct drm_pending_event base;
1047         struct drm_vmw_event_fence event;
1048 };
1049 
1050 static int vmw_event_fence_action_create(struct drm_file *file_priv,
1051                                   struct vmw_fence_obj *fence,
1052                                   uint32_t flags,
1053                                   uint64_t user_data,
1054                                   bool interruptible)
1055 {
1056         struct vmw_event_fence_pending *event;
1057         struct vmw_fence_manager *fman = fman_from_fence(fence);
1058         struct drm_device *dev = fman->dev_priv->dev;
1059         int ret;
1060 
1061         event = kzalloc(sizeof(*event), GFP_KERNEL);
1062         if (unlikely(!event)) {
1063                 DRM_ERROR("Failed to allocate an event.\n");
1064                 ret = -ENOMEM;
1065                 goto out_no_space;
1066         }
1067 
1068         event->event.base.type = DRM_VMW_EVENT_FENCE_SIGNALED;
1069         event->event.base.length = sizeof(*event);
1070         event->event.user_data = user_data;
1071 
1072         ret = drm_event_reserve_init(dev, file_priv, &event->base, &event->event.base);
1073 
1074         if (unlikely(ret != 0)) {
1075                 DRM_ERROR("Failed to allocate event space for this file.\n");
1076                 kfree(event);
1077                 goto out_no_space;
1078         }
1079 
1080         if (flags & DRM_VMW_FE_FLAG_REQ_TIME)
1081                 ret = vmw_event_fence_action_queue(file_priv, fence,
1082                                                    &event->base,
1083                                                    &event->event.tv_sec,
1084                                                    &event->event.tv_usec,
1085                                                    interruptible);
1086         else
1087                 ret = vmw_event_fence_action_queue(file_priv, fence,
1088                                                    &event->base,
1089                                                    NULL,
1090                                                    NULL,
1091                                                    interruptible);
1092         if (ret != 0)
1093                 goto out_no_queue;
1094 
1095         return 0;
1096 
1097 out_no_queue:
1098         drm_event_cancel_free(dev, &event->base);
1099 out_no_space:
1100         return ret;
1101 }
1102 
1103 int vmw_fence_event_ioctl(struct drm_device *dev, void *data,
1104                           struct drm_file *file_priv)
1105 {
1106         struct vmw_private *dev_priv = vmw_priv(dev);
1107         struct drm_vmw_fence_event_arg *arg =
1108                 (struct drm_vmw_fence_event_arg *) data;
1109         struct vmw_fence_obj *fence = NULL;
1110         struct vmw_fpriv *vmw_fp = vmw_fpriv(file_priv);
1111         struct ttm_object_file *tfile = vmw_fp->tfile;
1112         struct drm_vmw_fence_rep __user *user_fence_rep =
1113                 (struct drm_vmw_fence_rep __user *)(unsigned long)
1114                 arg->fence_rep;
1115         uint32_t handle;
1116         int ret;
1117 
1118         /*
1119          * Look up an existing fence object,
1120          * and if user-space wants a new reference,
1121          * add one.
1122          */
1123         if (arg->handle) {
1124                 struct ttm_base_object *base =
1125                         vmw_fence_obj_lookup(tfile, arg->handle);
1126 
1127                 if (IS_ERR(base))
1128                         return PTR_ERR(base);
1129 
1130                 fence = &(container_of(base, struct vmw_user_fence,
1131                                        base)->fence);
1132                 (void) vmw_fence_obj_reference(fence);
1133 
1134                 if (user_fence_rep != NULL) {
1135                         ret = ttm_ref_object_add(vmw_fp->tfile, base,
1136                                                  TTM_REF_USAGE, NULL, false);
1137                         if (unlikely(ret != 0)) {
1138                                 DRM_ERROR("Failed to reference a fence "
1139                                           "object.\n");
1140                                 goto out_no_ref_obj;
1141                         }
1142                         handle = base->handle;
1143                 }
1144                 ttm_base_object_unref(&base);
1145         }
1146 
1147         /*
1148          * Create a new fence object.
1149          */
1150         if (!fence) {
1151                 ret = vmw_execbuf_fence_commands(file_priv, dev_priv,
1152                                                  &fence,
1153                                                  (user_fence_rep) ?
1154                                                  &handle : NULL);
1155                 if (unlikely(ret != 0)) {
1156                         DRM_ERROR("Fence event failed to create fence.\n");
1157                         return ret;
1158                 }
1159         }
1160 
1161         BUG_ON(fence == NULL);
1162 
1163         ret = vmw_event_fence_action_create(file_priv, fence,
1164                                             arg->flags,
1165                                             arg->user_data,
1166                                             true);
1167         if (unlikely(ret != 0)) {
1168                 if (ret != -ERESTARTSYS)
1169                         DRM_ERROR("Failed to attach event to fence.\n");
1170                 goto out_no_create;
1171         }
1172 
1173         vmw_execbuf_copy_fence_user(dev_priv, vmw_fp, 0, user_fence_rep, fence,
1174                                     handle, -1, NULL);
1175         vmw_fence_obj_unreference(&fence);
1176         return 0;
1177 out_no_create:
1178         if (user_fence_rep != NULL)
1179                 ttm_ref_object_base_unref(tfile, handle, TTM_REF_USAGE);
1180 out_no_ref_obj:
1181         vmw_fence_obj_unreference(&fence);
1182         return ret;
1183 }