drivers/gpu/drm/vmwgfx/vmwgfx_fence.c

   1 // SPDX-License-Identifier: GPL-2.0 OR MIT
   2 /**************************************************************************
   3  *
   4  * Copyright 2011-2023 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         struct vmw_private *dev_priv;
  36         spinlock_t lock;
  37         struct list_head fence_list;
  38         struct work_struct work;
  39         bool fifo_down;
  40         struct list_head cleanup_list;
  41         uint32_t pending_actions[VMW_ACTION_MAX];
  42         struct mutex goal_irq_mutex;
  43         bool goal_irq_on; /* Protected by @goal_irq_mutex */
  44         bool seqno_valid; /* Protected by @lock, and may not be set to true
  45                              without the @goal_irq_mutex held. */
  46         u64 ctx;
  47 };
  48
  49 struct vmw_user_fence {
  50         struct ttm_base_object base;
  51         struct vmw_fence_obj fence;
  52 };
  53
  54 /**
  55  * struct vmw_event_fence_action - fence action that delivers a drm event.
  56  *
  57  * @action: A struct vmw_fence_action to hook up to a fence.
  58  * @event: A pointer to the pending event.
  59  * @fence: A referenced pointer to the fence to keep it alive while @action
  60  * hangs on it.
  61  * @dev: Pointer to a struct drm_device so we can access the event stuff.
  62  * @tv_sec: If non-null, the variable pointed to will be assigned
  63  * current time tv_sec val when the fence signals.
  64  * @tv_usec: Must be set if @tv_sec is set, and the variable pointed to will
  65  * be assigned the current time tv_usec val when the fence signals.
  66  */
  67 struct vmw_event_fence_action {
  68         struct vmw_fence_action action;
  69
  70         struct drm_pending_event *event;
  71         struct vmw_fence_obj *fence;
  72         struct drm_device *dev;
  73
  74         uint32_t *tv_sec;
  75         uint32_t *tv_usec;
  76 };
  77
  78 static struct vmw_fence_manager *
  79 fman_from_fence(struct vmw_fence_obj *fence)
  80 {
  81         return container_of(fence->base.lock, struct vmw_fence_manager, lock);
  82 }
  83
  84 static u32 vmw_fence_goal_read(struct vmw_private *vmw)
  85 {
  86         if ((vmw->capabilities2 & SVGA_CAP2_EXTRA_REGS) != 0)
  87                 return vmw_read(vmw, SVGA_REG_FENCE_GOAL);
  88         else
  89                 return vmw_fifo_mem_read(vmw, SVGA_FIFO_FENCE_GOAL);
  90 }
  91
  92 static void vmw_fence_goal_write(struct vmw_private *vmw, u32 value)
  93 {
  94         if ((vmw->capabilities2 & SVGA_CAP2_EXTRA_REGS) != 0)
  95                 vmw_write(vmw, SVGA_REG_FENCE_GOAL, value);
  96         else
  97                 vmw_fifo_mem_write(vmw, SVGA_FIFO_FENCE_GOAL, value);
  98 }
  99
 100 /*
 101  * Note on fencing subsystem usage of irqs:
 102  * Typically the vmw_fences_update function is called
 103  *
 104  * a) When a new fence seqno has been submitted by the fifo code.
 105  * b) On-demand when we have waiters. Sleeping waiters will switch on the
 106  * ANY_FENCE irq and call vmw_fences_update function each time an ANY_FENCE
 107  * irq is received. When the last fence waiter is gone, that IRQ is masked
 108  * away.
 109  *
 110  * In situations where there are no waiters and we don't submit any new fences,
 111  * fence objects may not be signaled. This is perfectly OK, since there are
 112  * no consumers of the signaled data, but that is NOT ok when there are fence
 113  * actions attached to a fence. The fencing subsystem then makes use of the
 114  * FENCE_GOAL irq and sets the fence goal seqno to that of the next fence
 115  * which has an action attached, and each time vmw_fences_update is called,
 116  * the subsystem makes sure the fence goal seqno is updated.
 117  *
 118  * The fence goal seqno irq is on as long as there are unsignaled fence
 119  * objects with actions attached to them.
 120  */
 121
 122 static void vmw_fence_obj_destroy(struct dma_fence *f)
 123 {
 124         struct vmw_fence_obj *fence =
 125                 container_of(f, struct vmw_fence_obj, base);
 126         struct vmw_fence_manager *fman = fman_from_fence(fence);
 127
 128         if (!list_empty(&fence->head)) {
 129                 spin_lock(&fman->lock);
 130                 list_del_init(&fence->head);
 131                 spin_unlock(&fman->lock);
 132         }
 133         fence->destroy(fence);
 134 }
 135
 136 static const char *vmw_fence_get_driver_name(struct dma_fence *f)
 137 {
 138         return "vmwgfx";
 139 }
 140
 141 static const char *vmw_fence_get_timeline_name(struct dma_fence *f)
 142 {
 143         return "svga";
 144 }
 145
 146 static bool vmw_fence_enable_signaling(struct dma_fence *f)
 147 {
 148         struct vmw_fence_obj *fence =
 149                 container_of(f, struct vmw_fence_obj, base);
 150
 151         struct vmw_fence_manager *fman = fman_from_fence(fence);
 152         struct vmw_private *dev_priv = fman->dev_priv;
 153
 154         u32 seqno = vmw_fence_read(dev_priv);
 155         if (seqno - fence->base.seqno < VMW_FENCE_WRAP)
 156                 return false;
 157
 158         return true;
 159 }
 160
 161 struct vmwgfx_wait_cb {
 162         struct dma_fence_cb base;
 163         struct task_struct *task;
 164 };
 165
 166 static void
 167 vmwgfx_wait_cb(struct dma_fence *fence, struct dma_fence_cb *cb)
 168 {
 169         struct vmwgfx_wait_cb *wait =
 170                 container_of(cb, struct vmwgfx_wait_cb, base);
 171
 172         wake_up_process(wait->task);
 173 }
 174
 175 static void __vmw_fences_update(struct vmw_fence_manager *fman);
 176
 177 static long vmw_fence_wait(struct dma_fence *f, bool intr, signed long timeout)
 178 {
 179         struct vmw_fence_obj *fence =
 180                 container_of(f, struct vmw_fence_obj, base);
 181
 182         struct vmw_fence_manager *fman = fman_from_fence(fence);
 183         struct vmw_private *dev_priv = fman->dev_priv;
 184         struct vmwgfx_wait_cb cb;
 185         long ret = timeout;
 186
 187         if (likely(vmw_fence_obj_signaled(fence)))
 188                 return timeout;
 189
 190         vmw_seqno_waiter_add(dev_priv);
 191
 192         spin_lock(f->lock);
 193
 194         if (test_bit(DMA_FENCE_FLAG_SIGNALED_BIT, &f->flags))
 195                 goto out;
 196
 197         if (intr && signal_pending(current)) {
 198                 ret = -ERESTARTSYS;
 199                 goto out;
 200         }
 201
 202         cb.base.func = vmwgfx_wait_cb;
 203         cb.task = current;
 204         list_add(&cb.base.node, &f->cb_list);
 205
 206         for (;;) {
 207                 __vmw_fences_update(fman);
 208
 209                 /*
 210                  * We can use the barrier free __set_current_state() since
 211                  * DMA_FENCE_FLAG_SIGNALED_BIT + wakeup is protected by the
 212                  * fence spinlock.
 213                  */
 214                 if (intr)
 215                         __set_current_state(TASK_INTERRUPTIBLE);
 216                 else
 217                         __set_current_state(TASK_UNINTERRUPTIBLE);
 218
 219                 if (test_bit(DMA_FENCE_FLAG_SIGNALED_BIT, &f->flags)) {
 220                         if (ret == 0 && timeout > 0)
 221                                 ret = 1;
 222                         break;
 223                 }
 224
 225                 if (intr && signal_pending(current)) {
 226                         ret = -ERESTARTSYS;
 227                         break;
 228                 }
 229
 230                 if (ret == 0)
 231                         break;
 232
 233                 spin_unlock(f->lock);
 234
 235                 ret = schedule_timeout(ret);
 236
 237                 spin_lock(f->lock);
 238         }
 239         __set_current_state(TASK_RUNNING);
 240         if (!list_empty(&cb.base.node))
 241                 list_del(&cb.base.node);
 242
 243 out:
 244         spin_unlock(f->lock);
 245
 246         vmw_seqno_waiter_remove(dev_priv);
 247
 248         return ret;
 249 }
 250
 251 static const struct dma_fence_ops vmw_fence_ops = {
 252         .get_driver_name = vmw_fence_get_driver_name,
 253         .get_timeline_name = vmw_fence_get_timeline_name,
 254         .enable_signaling = vmw_fence_enable_signaling,
 255         .wait = vmw_fence_wait,
 256         .release = vmw_fence_obj_destroy,
 257 };
 258
 259 /*
 260  * Execute signal actions on fences recently signaled.
 261  * This is done from a workqueue so we don't have to execute
 262  * signal actions from atomic context.
 263  */
 264
 265 static void vmw_fence_work_func(struct work_struct *work)
 266 {
 267         struct vmw_fence_manager *fman =
 268                 container_of(work, struct vmw_fence_manager, work);
 269         struct list_head list;
 270         struct vmw_fence_action *action, *next_action;
 271         bool seqno_valid;
 272
 273         do {
 274                 INIT_LIST_HEAD(&list);
 275                 mutex_lock(&fman->goal_irq_mutex);
 276
 277                 spin_lock(&fman->lock);
 278                 list_splice_init(&fman->cleanup_list, &list);
 279                 seqno_valid = fman->seqno_valid;
 280                 spin_unlock(&fman->lock);
 281
 282                 if (!seqno_valid && fman->goal_irq_on) {
 283                         fman->goal_irq_on = false;
 284                         vmw_goal_waiter_remove(fman->dev_priv);
 285                 }
 286                 mutex_unlock(&fman->goal_irq_mutex);
 287
 288                 if (list_empty(&list))
 289                         return;
 290
 291                 /*
 292                  * At this point, only we should be able to manipulate the
 293                  * list heads of the actions we have on the private list.
 294                  * hence fman::lock not held.
 295                  */
 296
 297                 list_for_each_entry_safe(action, next_action, &list, head) {
 298                         list_del_init(&action->head);
 299                         if (action->cleanup)
 300                                 action->cleanup(action);
 301                 }
 302         } while (1);
 303 }
 304
 305 struct vmw_fence_manager *vmw_fence_manager_init(struct vmw_private *dev_priv)
 306 {
 307         struct vmw_fence_manager *fman = kzalloc(sizeof(*fman), GFP_KERNEL);
 308
 309         if (unlikely(!fman))
 310                 return NULL;
 311
 312         fman->dev_priv = dev_priv;
 313         spin_lock_init(&fman->lock);
 314         INIT_LIST_HEAD(&fman->fence_list);
 315         INIT_LIST_HEAD(&fman->cleanup_list);
 316         INIT_WORK(&fman->work, &vmw_fence_work_func);
 317         fman->fifo_down = true;
 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
 357 out_unlock:
 358         spin_unlock(&fman->lock);
 359         return ret;
 360
 361 }
 362
 363 static void vmw_fences_perform_actions(struct vmw_fence_manager *fman,
 364                                 struct list_head *list)
 365 {
 366         struct vmw_fence_action *action, *next_action;
 367
 368         list_for_each_entry_safe(action, next_action, list, head) {
 369                 list_del_init(&action->head);
 370                 fman->pending_actions[action->type]--;
 371                 if (action->seq_passed != NULL)
 372                         action->seq_passed(action);
 373
 374                 /*
 375                  * Add the cleanup action to the cleanup list so that
 376                  * it will be performed by a worker task.
 377                  */
 378
 379                 list_add_tail(&action->head, &fman->cleanup_list);
 380         }
 381 }
 382
 383 /**
 384  * vmw_fence_goal_new_locked - Figure out a new device fence goal
 385  * seqno if needed.
 386  *
 387  * @fman: Pointer to a fence manager.
 388  * @passed_seqno: The seqno the device currently signals as passed.
 389  *
 390  * This function should be called with the fence manager lock held.
 391  * It is typically called when we have a new passed_seqno, and
 392  * we might need to update the fence goal. It checks to see whether
 393  * the current fence goal has already passed, and, in that case,
 394  * scans through all unsignaled fences to get the next fence object with an
 395  * action attached, and sets the seqno of that fence as a new fence goal.
 396  *
 397  * returns true if the device goal seqno was updated. False otherwise.
 398  */
 399 static bool vmw_fence_goal_new_locked(struct vmw_fence_manager *fman,
 400                                       u32 passed_seqno)
 401 {
 402         u32 goal_seqno;
 403         struct vmw_fence_obj *fence, *next_fence;
 404
 405         if (likely(!fman->seqno_valid))
 406                 return false;
 407
 408         goal_seqno = vmw_fence_goal_read(fman->dev_priv);
 409         if (likely(passed_seqno - goal_seqno >= VMW_FENCE_WRAP))
 410                 return false;
 411
 412         fman->seqno_valid = false;
 413         list_for_each_entry_safe(fence, next_fence, &fman->fence_list, head) {
 414                 if (!list_empty(&fence->seq_passed_actions)) {
 415                         fman->seqno_valid = true;
 416                         vmw_fence_goal_write(fman->dev_priv,
 417                                              fence->base.seqno);
 418                         break;
 419                 }
 420         }
 421
 422         return true;
 423 }
 424
 425
 426 /**
 427  * vmw_fence_goal_check_locked - Replace the device fence goal seqno if
 428  * needed.
 429  *
 430  * @fence: Pointer to a struct vmw_fence_obj the seqno of which should be
 431  * considered as a device fence goal.
 432  *
 433  * This function should be called with the fence manager lock held.
 434  * It is typically called when an action has been attached to a fence to
 435  * check whether the seqno of that fence should be used for a fence
 436  * goal interrupt. This is typically needed if the current fence goal is
 437  * invalid, or has a higher seqno than that of the current fence object.
 438  *
 439  * returns true if the device goal seqno was updated. False otherwise.
 440  */
 441 static bool vmw_fence_goal_check_locked(struct vmw_fence_obj *fence)
 442 {
 443         struct vmw_fence_manager *fman = fman_from_fence(fence);
 444         u32 goal_seqno;
 445
 446         if (dma_fence_is_signaled_locked(&fence->base))
 447                 return false;
 448
 449         goal_seqno = vmw_fence_goal_read(fman->dev_priv);
 450         if (likely(fman->seqno_valid &&
 451                    goal_seqno - fence->base.seqno < VMW_FENCE_WRAP))
 452                 return false;
 453
 454         vmw_fence_goal_write(fman->dev_priv, fence->base.seqno);
 455         fman->seqno_valid = true;
 456
 457         return true;
 458 }
 459
 460 static void __vmw_fences_update(struct vmw_fence_manager *fman)
 461 {
 462         struct vmw_fence_obj *fence, *next_fence;
 463         struct list_head action_list;
 464         bool needs_rerun;
 465         uint32_t seqno, new_seqno;
 466
 467         seqno = vmw_fence_read(fman->dev_priv);
 468 rerun:
 469         list_for_each_entry_safe(fence, next_fence, &fman->fence_list, head) {
 470                 if (seqno - fence->base.seqno < VMW_FENCE_WRAP) {
 471                         list_del_init(&fence->head);
 472                         dma_fence_signal_locked(&fence->base);
 473                         INIT_LIST_HEAD(&action_list);
 474                         list_splice_init(&fence->seq_passed_actions,
 475                                          &action_list);
 476                         vmw_fences_perform_actions(fman, &action_list);
 477                 } else
 478                         break;
 479         }
 480
 481         /*
 482          * Rerun if the fence goal seqno was updated, and the
 483          * hardware might have raced with that update, so that
 484          * we missed a fence_goal irq.
 485          */
 486
 487         needs_rerun = vmw_fence_goal_new_locked(fman, seqno);
 488         if (unlikely(needs_rerun)) {
 489                 new_seqno = vmw_fence_read(fman->dev_priv);
 490                 if (new_seqno != seqno) {
 491                         seqno = new_seqno;
 492                         goto rerun;
 493                 }
 494         }
 495
 496         if (!list_empty(&fman->cleanup_list))
 497                 (void) schedule_work(&fman->work);
 498 }
 499
 500 void vmw_fences_update(struct vmw_fence_manager *fman)
 501 {
 502         spin_lock(&fman->lock);
 503         __vmw_fences_update(fman);
 504         spin_unlock(&fman->lock);
 505 }
 506
 507 bool vmw_fence_obj_signaled(struct vmw_fence_obj *fence)
 508 {
 509         struct vmw_fence_manager *fman = fman_from_fence(fence);
 510
 511         if (test_bit(DMA_FENCE_FLAG_SIGNALED_BIT, &fence->base.flags))
 512                 return true;
 513
 514         vmw_fences_update(fman);
 515
 516         return dma_fence_is_signaled(&fence->base);
 517 }
 518
 519 int vmw_fence_obj_wait(struct vmw_fence_obj *fence, bool lazy,
 520                        bool interruptible, unsigned long timeout)
 521 {
 522         long ret = dma_fence_wait_timeout(&fence->base, interruptible, timeout);
 523
 524         if (likely(ret > 0))
 525                 return 0;
 526         else if (ret == 0)
 527                 return -EBUSY;
 528         else
 529                 return ret;
 530 }
 531
 532 static void vmw_fence_destroy(struct vmw_fence_obj *fence)
 533 {
 534         dma_fence_free(&fence->base);
 535 }
 536
 537 int vmw_fence_create(struct vmw_fence_manager *fman,
 538                      uint32_t seqno,
 539                      struct vmw_fence_obj **p_fence)
 540 {
 541         struct vmw_fence_obj *fence;
 542         int ret;
 543
 544         fence = kzalloc(sizeof(*fence), GFP_KERNEL);
 545         if (unlikely(!fence))
 546                 return -ENOMEM;
 547
 548         ret = vmw_fence_obj_init(fman, fence, seqno,
 549                                  vmw_fence_destroy);
 550         if (unlikely(ret != 0))
 551                 goto out_err_init;
 552
 553         *p_fence = fence;
 554         return 0;
 555
 556 out_err_init:
 557         kfree(fence);
 558         return ret;
 559 }
 560
 561
 562 static void vmw_user_fence_destroy(struct vmw_fence_obj *fence)
 563 {
 564         struct vmw_user_fence *ufence =
 565                 container_of(fence, struct vmw_user_fence, fence);
 566
 567         ttm_base_object_kfree(ufence, base);
 568 }
 569
 570 static void vmw_user_fence_base_release(struct ttm_base_object **p_base)
 571 {
 572         struct ttm_base_object *base = *p_base;
 573         struct vmw_user_fence *ufence =
 574                 container_of(base, struct vmw_user_fence, base);
 575         struct vmw_fence_obj *fence = &ufence->fence;
 576
 577         *p_base = NULL;
 578         vmw_fence_obj_unreference(&fence);
 579 }
 580
 581 int vmw_user_fence_create(struct drm_file *file_priv,
 582                           struct vmw_fence_manager *fman,
 583                           uint32_t seqno,
 584                           struct vmw_fence_obj **p_fence,
 585                           uint32_t *p_handle)
 586 {
 587         struct ttm_object_file *tfile = vmw_fpriv(file_priv)->tfile;
 588         struct vmw_user_fence *ufence;
 589         struct vmw_fence_obj *tmp;
 590         int ret;
 591
 592         ufence = kzalloc(sizeof(*ufence), GFP_KERNEL);
 593         if (unlikely(!ufence)) {
 594                 ret = -ENOMEM;
 595                 goto out_no_object;
 596         }
 597
 598         ret = vmw_fence_obj_init(fman, &ufence->fence, seqno,
 599                                  vmw_user_fence_destroy);
 600         if (unlikely(ret != 0)) {
 601                 kfree(ufence);
 602                 goto out_no_object;
 603         }
 604
 605         /*
 606          * The base object holds a reference which is freed in
 607          * vmw_user_fence_base_release.
 608          */
 609         tmp = vmw_fence_obj_reference(&ufence->fence);
 610
 611         ret = ttm_base_object_init(tfile, &ufence->base, false,
 612                                    VMW_RES_FENCE,
 613                                    &vmw_user_fence_base_release);
 614
 615
 616         if (unlikely(ret != 0)) {
 617                 /*
 618                  * Free the base object's reference
 619                  */
 620                 vmw_fence_obj_unreference(&tmp);
 621                 goto out_err;
 622         }
 623
 624         *p_fence = &ufence->fence;
 625         *p_handle = ufence->base.handle;
 626
 627         return 0;
 628 out_err:
 629         tmp = &ufence->fence;
 630         vmw_fence_obj_unreference(&tmp);
 631 out_no_object:
 632         return ret;
 633 }
 634
 635 /*
 636  * vmw_fence_fifo_down - signal all unsignaled fence objects.
 637  */
 638
 639 void vmw_fence_fifo_down(struct vmw_fence_manager *fman)
 640 {
 641         struct list_head action_list;
 642         int ret;
 643
 644         /*
 645          * The list may be altered while we traverse it, so always
 646          * restart when we've released the fman->lock.
 647          */
 648
 649         spin_lock(&fman->lock);
 650         fman->fifo_down = true;
 651         while (!list_empty(&fman->fence_list)) {
 652                 struct vmw_fence_obj *fence =
 653                         list_entry(fman->fence_list.prev, struct vmw_fence_obj,
 654                                    head);
 655                 dma_fence_get(&fence->base);
 656                 spin_unlock(&fman->lock);
 657
 658                 ret = vmw_fence_obj_wait(fence, false, false,
 659                                          VMW_FENCE_WAIT_TIMEOUT);
 660
 661                 if (unlikely(ret != 0)) {
 662                         list_del_init(&fence->head);
 663                         dma_fence_signal(&fence->base);
 664                         INIT_LIST_HEAD(&action_list);
 665                         list_splice_init(&fence->seq_passed_actions,
 666                                          &action_list);
 667                         vmw_fences_perform_actions(fman, &action_list);
 668                 }
 669
 670                 BUG_ON(!list_empty(&fence->head));
 671                 dma_fence_put(&fence->base);
 672                 spin_lock(&fman->lock);
 673         }
 674         spin_unlock(&fman->lock);
 675 }
 676
 677 void vmw_fence_fifo_up(struct vmw_fence_manager *fman)
 678 {
 679         spin_lock(&fman->lock);
 680         fman->fifo_down = false;
 681         spin_unlock(&fman->lock);
 682 }
 683
 684
 685 /**
 686  * vmw_fence_obj_lookup - Look up a user-space fence object
 687  *
 688  * @tfile: A struct ttm_object_file identifying the caller.
 689  * @handle: A handle identifying the fence object.
 690  * @return: A struct vmw_user_fence base ttm object on success or
 691  * an error pointer on failure.
 692  *
 693  * The fence object is looked up and type-checked. The caller needs
 694  * to have opened the fence object first, but since that happens on
 695  * creation and fence objects aren't shareable, that's not an
 696  * issue currently.
 697  */
 698 static struct ttm_base_object *
 699 vmw_fence_obj_lookup(struct ttm_object_file *tfile, u32 handle)
 700 {
 701         struct ttm_base_object *base = ttm_base_object_lookup(tfile, handle);
 702
 703         if (!base) {
 704                 pr_err("Invalid fence object handle 0x%08lx.\n",
 705                        (unsigned long)handle);
 706                 return ERR_PTR(-EINVAL);
 707         }
 708
 709         if (base->refcount_release != vmw_user_fence_base_release) {
 710                 pr_err("Invalid fence object handle 0x%08lx.\n",
 711                        (unsigned long)handle);
 712                 ttm_base_object_unref(&base);
 713                 return ERR_PTR(-EINVAL);
 714         }
 715
 716         return base;
 717 }
 718
 719
 720 int vmw_fence_obj_wait_ioctl(struct drm_device *dev, void *data,
 721                              struct drm_file *file_priv)
 722 {
 723         struct drm_vmw_fence_wait_arg *arg =
 724             (struct drm_vmw_fence_wait_arg *)data;
 725         unsigned long timeout;
 726         struct ttm_base_object *base;
 727         struct vmw_fence_obj *fence;
 728         struct ttm_object_file *tfile = vmw_fpriv(file_priv)->tfile;
 729         int ret;
 730         uint64_t wait_timeout = ((uint64_t)arg->timeout_us * HZ);
 731
 732         /*
 733          * 64-bit division not present on 32-bit systems, so do an
 734          * approximation. (Divide by 1000000).
 735          */
 736
 737         wait_timeout = (wait_timeout >> 20) + (wait_timeout >> 24) -
 738           (wait_timeout >> 26);
 739
 740         if (!arg->cookie_valid) {
 741                 arg->cookie_valid = 1;
 742                 arg->kernel_cookie = jiffies + wait_timeout;
 743         }
 744
 745         base = vmw_fence_obj_lookup(tfile, arg->handle);
 746         if (IS_ERR(base))
 747                 return PTR_ERR(base);
 748
 749         fence = &(container_of(base, struct vmw_user_fence, base)->fence);
 750
 751         timeout = jiffies;
 752         if (time_after_eq(timeout, (unsigned long)arg->kernel_cookie)) {
 753                 ret = ((vmw_fence_obj_signaled(fence)) ?
 754                        0 : -EBUSY);
 755                 goto out;
 756         }
 757
 758         timeout = (unsigned long)arg->kernel_cookie - timeout;
 759
 760         ret = vmw_fence_obj_wait(fence, arg->lazy, true, timeout);
 761
 762 out:
 763         ttm_base_object_unref(&base);
 764
 765         /*
 766          * Optionally unref the fence object.
 767          */
 768
 769         if (ret == 0 && (arg->wait_options & DRM_VMW_WAIT_OPTION_UNREF))
 770                 return ttm_ref_object_base_unref(tfile, arg->handle);
 771         return ret;
 772 }
 773
 774 int vmw_fence_obj_signaled_ioctl(struct drm_device *dev, void *data,
 775                                  struct drm_file *file_priv)
 776 {
 777         struct drm_vmw_fence_signaled_arg *arg =
 778                 (struct drm_vmw_fence_signaled_arg *) data;
 779         struct ttm_base_object *base;
 780         struct vmw_fence_obj *fence;
 781         struct vmw_fence_manager *fman;
 782         struct ttm_object_file *tfile = vmw_fpriv(file_priv)->tfile;
 783         struct vmw_private *dev_priv = vmw_priv(dev);
 784
 785         base = vmw_fence_obj_lookup(tfile, arg->handle);
 786         if (IS_ERR(base))
 787                 return PTR_ERR(base);
 788
 789         fence = &(container_of(base, struct vmw_user_fence, base)->fence);
 790         fman = fman_from_fence(fence);
 791
 792         arg->signaled = vmw_fence_obj_signaled(fence);
 793
 794         arg->signaled_flags = arg->flags;
 795         spin_lock(&fman->lock);
 796         arg->passed_seqno = dev_priv->last_read_seqno;
 797         spin_unlock(&fman->lock);
 798
 799         ttm_base_object_unref(&base);
 800
 801         return 0;
 802 }
 803
 804
 805 int vmw_fence_obj_unref_ioctl(struct drm_device *dev, void *data,
 806                               struct drm_file *file_priv)
 807 {
 808         struct drm_vmw_fence_arg *arg =
 809                 (struct drm_vmw_fence_arg *) data;
 810
 811         return ttm_ref_object_base_unref(vmw_fpriv(file_priv)->tfile,
 812                                          arg->handle);
 813 }
 814
 815 /**
 816  * vmw_event_fence_action_seq_passed
 817  *
 818  * @action: The struct vmw_fence_action embedded in a struct
 819  * vmw_event_fence_action.
 820  *
 821  * This function is called when the seqno of the fence where @action is
 822  * attached has passed. It queues the event on the submitter's event list.
 823  * This function is always called from atomic context.
 824  */
 825 static void vmw_event_fence_action_seq_passed(struct vmw_fence_action *action)
 826 {
 827         struct vmw_event_fence_action *eaction =
 828                 container_of(action, struct vmw_event_fence_action, action);
 829         struct drm_device *dev = eaction->dev;
 830         struct drm_pending_event *event = eaction->event;
 831
 832         if (unlikely(event == NULL))
 833                 return;
 834
 835         spin_lock_irq(&dev->event_lock);
 836
 837         if (likely(eaction->tv_sec != NULL)) {
 838                 struct timespec64 ts;
 839
 840                 ktime_get_ts64(&ts);
 841                 /* monotonic time, so no y2038 overflow */
 842                 *eaction->tv_sec = ts.tv_sec;
 843                 *eaction->tv_usec = ts.tv_nsec / NSEC_PER_USEC;
 844         }
 845
 846         drm_send_event_locked(dev, eaction->event);
 847         eaction->event = NULL;
 848         spin_unlock_irq(&dev->event_lock);
 849 }
 850
 851 /**
 852  * vmw_event_fence_action_cleanup
 853  *
 854  * @action: The struct vmw_fence_action embedded in a struct
 855  * vmw_event_fence_action.
 856  *
 857  * This function is the struct vmw_fence_action destructor. It's typically
 858  * called from a workqueue.
 859  */
 860 static void vmw_event_fence_action_cleanup(struct vmw_fence_action *action)
 861 {
 862         struct vmw_event_fence_action *eaction =
 863                 container_of(action, struct vmw_event_fence_action, action);
 864
 865         vmw_fence_obj_unreference(&eaction->fence);
 866         kfree(eaction);
 867 }
 868
 869
 870 /**
 871  * vmw_fence_obj_add_action - Add an action to a fence object.
 872  *
 873  * @fence: The fence object.
 874  * @action: The action to add.
 875  *
 876  * Note that the action callbacks may be executed before this function
 877  * returns.
 878  */
 879 static void vmw_fence_obj_add_action(struct vmw_fence_obj *fence,
 880                               struct vmw_fence_action *action)
 881 {
 882         struct vmw_fence_manager *fman = fman_from_fence(fence);
 883         bool run_update = false;
 884
 885         mutex_lock(&fman->goal_irq_mutex);
 886         spin_lock(&fman->lock);
 887
 888         fman->pending_actions[action->type]++;
 889         if (dma_fence_is_signaled_locked(&fence->base)) {
 890                 struct list_head action_list;
 891
 892                 INIT_LIST_HEAD(&action_list);
 893                 list_add_tail(&action->head, &action_list);
 894                 vmw_fences_perform_actions(fman, &action_list);
 895         } else {
 896                 list_add_tail(&action->head, &fence->seq_passed_actions);
 897
 898                 /*
 899                  * This function may set fman::seqno_valid, so it must
 900                  * be run with the goal_irq_mutex held.
 901                  */
 902                 run_update = vmw_fence_goal_check_locked(fence);
 903         }
 904
 905         spin_unlock(&fman->lock);
 906
 907         if (run_update) {
 908                 if (!fman->goal_irq_on) {
 909                         fman->goal_irq_on = true;
 910                         vmw_goal_waiter_add(fman->dev_priv);
 911                 }
 912                 vmw_fences_update(fman);
 913         }
 914         mutex_unlock(&fman->goal_irq_mutex);
 915
 916 }
 917
 918 /**
 919  * vmw_event_fence_action_queue - Post an event for sending when a fence
 920  * object seqno has passed.
 921  *
 922  * @file_priv: The file connection on which the event should be posted.
 923  * @fence: The fence object on which to post the event.
 924  * @event: Event to be posted. This event should've been alloced
 925  * using k[mz]alloc, and should've been completely initialized.
 926  * @tv_sec: If non-null, the variable pointed to will be assigned
 927  * current time tv_sec val when the fence signals.
 928  * @tv_usec: Must be set if @tv_sec is set, and the variable pointed to will
 929  * be assigned the current time tv_usec val when the fence signals.
 930  * @interruptible: Interruptible waits if possible.
 931  *
 932  * As a side effect, the object pointed to by @event may have been
 933  * freed when this function returns. If this function returns with
 934  * an error code, the caller needs to free that object.
 935  */
 936
 937 int vmw_event_fence_action_queue(struct drm_file *file_priv,
 938                                  struct vmw_fence_obj *fence,
 939                                  struct drm_pending_event *event,
 940                                  uint32_t *tv_sec,
 941                                  uint32_t *tv_usec,
 942                                  bool interruptible)
 943 {
 944         struct vmw_event_fence_action *eaction;
 945         struct vmw_fence_manager *fman = fman_from_fence(fence);
 946
 947         eaction = kzalloc(sizeof(*eaction), GFP_KERNEL);
 948         if (unlikely(!eaction))
 949                 return -ENOMEM;
 950
 951         eaction->event = event;
 952
 953         eaction->action.seq_passed = vmw_event_fence_action_seq_passed;
 954         eaction->action.cleanup = vmw_event_fence_action_cleanup;
 955         eaction->action.type = VMW_ACTION_EVENT;
 956
 957         eaction->fence = vmw_fence_obj_reference(fence);
 958         eaction->dev = &fman->dev_priv->drm;
 959         eaction->tv_sec = tv_sec;
 960         eaction->tv_usec = tv_usec;
 961
 962         vmw_fence_obj_add_action(fence, &eaction->action);
 963
 964         return 0;
 965 }
 966
 967 struct vmw_event_fence_pending {
 968         struct drm_pending_event base;
 969         struct drm_vmw_event_fence event;
 970 };
 971
 972 static int vmw_event_fence_action_create(struct drm_file *file_priv,
 973                                   struct vmw_fence_obj *fence,
 974                                   uint32_t flags,
 975                                   uint64_t user_data,
 976                                   bool interruptible)
 977 {
 978         struct vmw_event_fence_pending *event;
 979         struct vmw_fence_manager *fman = fman_from_fence(fence);
 980         struct drm_device *dev = &fman->dev_priv->drm;
 981         int ret;
 982
 983         event = kzalloc(sizeof(*event), GFP_KERNEL);
 984         if (unlikely(!event)) {
 985                 DRM_ERROR("Failed to allocate an event.\n");
 986                 ret = -ENOMEM;
 987                 goto out_no_space;
 988         }
 989
 990         event->event.base.type = DRM_VMW_EVENT_FENCE_SIGNALED;
 991         event->event.base.length = sizeof(event->event);
 992         event->event.user_data = user_data;
 993
 994         ret = drm_event_reserve_init(dev, file_priv, &event->base, &event->event.base);
 995
 996         if (unlikely(ret != 0)) {
 997                 DRM_ERROR("Failed to allocate event space for this file.\n");
 998                 kfree(event);
 999                 goto out_no_space;
1000         }
1001
1002         if (flags & DRM_VMW_FE_FLAG_REQ_TIME)
1003                 ret = vmw_event_fence_action_queue(file_priv, fence,
1004                                                    &event->base,
1005                                                    &event->event.tv_sec,
1006                                                    &event->event.tv_usec,
1007                                                    interruptible);
1008         else
1009                 ret = vmw_event_fence_action_queue(file_priv, fence,
1010                                                    &event->base,
1011                                                    NULL,
1012                                                    NULL,
1013                                                    interruptible);
1014         if (ret != 0)
1015                 goto out_no_queue;
1016
1017         return 0;
1018
1019 out_no_queue:
1020         drm_event_cancel_free(dev, &event->base);
1021 out_no_space:
1022         return ret;
1023 }
1024
1025 int vmw_fence_event_ioctl(struct drm_device *dev, void *data,
1026                           struct drm_file *file_priv)
1027 {
1028         struct vmw_private *dev_priv = vmw_priv(dev);
1029         struct drm_vmw_fence_event_arg *arg =
1030                 (struct drm_vmw_fence_event_arg *) data;
1031         struct vmw_fence_obj *fence = NULL;
1032         struct vmw_fpriv *vmw_fp = vmw_fpriv(file_priv);
1033         struct ttm_object_file *tfile = vmw_fp->tfile;
1034         struct drm_vmw_fence_rep __user *user_fence_rep =
1035                 (struct drm_vmw_fence_rep __user *)(unsigned long)
1036                 arg->fence_rep;
1037         uint32_t handle;
1038         int ret;
1039
1040         /*
1041          * Look up an existing fence object,
1042          * and if user-space wants a new reference,
1043          * add one.
1044          */
1045         if (arg->handle) {
1046                 struct ttm_base_object *base =
1047                         vmw_fence_obj_lookup(tfile, arg->handle);
1048
1049                 if (IS_ERR(base))
1050                         return PTR_ERR(base);
1051
1052                 fence = &(container_of(base, struct vmw_user_fence,
1053                                        base)->fence);
1054                 (void) vmw_fence_obj_reference(fence);
1055
1056                 if (user_fence_rep != NULL) {
1057                         ret = ttm_ref_object_add(vmw_fp->tfile, base,
1058                                                  NULL, false);
1059                         if (unlikely(ret != 0)) {
1060                                 DRM_ERROR("Failed to reference a fence "
1061                                           "object.\n");
1062                                 goto out_no_ref_obj;
1063                         }
1064                         handle = base->handle;
1065                 }
1066                 ttm_base_object_unref(&base);
1067         }
1068
1069         /*
1070          * Create a new fence object.
1071          */
1072         if (!fence) {
1073                 ret = vmw_execbuf_fence_commands(file_priv, dev_priv,
1074                                                  &fence,
1075                                                  (user_fence_rep) ?
1076                                                  &handle : NULL);
1077                 if (unlikely(ret != 0)) {
1078                         DRM_ERROR("Fence event failed to create fence.\n");
1079                         return ret;
1080                 }
1081         }
1082
1083         BUG_ON(fence == NULL);
1084
1085         ret = vmw_event_fence_action_create(file_priv, fence,
1086                                             arg->flags,
1087                                             arg->user_data,
1088                                             true);
1089         if (unlikely(ret != 0)) {
1090                 if (ret != -ERESTARTSYS)
1091                         DRM_ERROR("Failed to attach event to fence.\n");
1092                 goto out_no_create;
1093         }
1094
1095         vmw_execbuf_copy_fence_user(dev_priv, vmw_fp, 0, user_fence_rep, fence,
1096                                     handle, -1);
1097         vmw_fence_obj_unreference(&fence);
1098         return 0;
1099 out_no_create:
1100         if (user_fence_rep != NULL)
1101                 ttm_ref_object_base_unref(tfile, handle);
1102 out_no_ref_obj:
1103         vmw_fence_obj_unreference(&fence);
1104         return ret;
1105 }