drivers/gpu/drm/vmwgfx/vmwgfx_fence.c

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