drivers/gpu/drm/qxl/qxl_cmd.c

   1 /*
   2  * Copyright 2013 Red Hat Inc.
   3  *
   4  * Permission is hereby granted, free of charge, to any person obtaining a
   5  * copy of this software and associated documentation files (the "Software"),
   6  * to deal in the Software without restriction, including without limitation
   7  * the rights to use, copy, modify, merge, publish, distribute, sublicense,
   8  * and/or sell copies of the Software, and to permit persons to whom the
   9  * Software is furnished to do so, subject to the following conditions:
  10  *
  11  * The above copyright notice and this permission notice shall be included in
  12  * all copies or substantial portions of the Software.
  13  *
  14  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
  15  * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
  16  * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL
  17  * THE COPYRIGHT HOLDER(S) OR AUTHOR(S) BE LIABLE FOR ANY CLAIM, DAMAGES OR
  18  * OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE,
  19  * ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR
  20  * OTHER DEALINGS IN THE SOFTWARE.
  21  *
  22  * Authors: Dave Airlie
  23  *          Alon Levy
  24  */
  25
  26 /* QXL cmd/ring handling */
  27
  28 #include "qxl_drv.h"
  29 #include "qxl_object.h"
  30
  31 static int qxl_reap_surface_id(struct qxl_device *qdev, int max_to_reap);
  32
  33 struct ring {
  34         struct qxl_ring_header      header;
  35         uint8_t                     elements[0];
  36 };
  37
  38 struct qxl_ring {
  39         struct ring            *ring;
  40         int                     element_size;
  41         int                     n_elements;
  42         int                     prod_notify;
  43         wait_queue_head_t      *push_event;
  44         spinlock_t             lock;
  45 };
  46
  47 void qxl_ring_free(struct qxl_ring *ring)
  48 {
  49         kfree(ring);
  50 }
  51
  52 void qxl_ring_init_hdr(struct qxl_ring *ring)
  53 {
  54         ring->ring->header.notify_on_prod = ring->n_elements;
  55 }
  56
  57 struct qxl_ring *
  58 qxl_ring_create(struct qxl_ring_header *header,
  59                 int element_size,
  60                 int n_elements,
  61                 int prod_notify,
  62                 bool set_prod_notify,
  63                 wait_queue_head_t *push_event)
  64 {
  65         struct qxl_ring *ring;
  66
  67         ring = kmalloc(sizeof(*ring), GFP_KERNEL);
  68         if (!ring)
  69                 return NULL;
  70
  71         ring->ring = (struct ring *)header;
  72         ring->element_size = element_size;
  73         ring->n_elements = n_elements;
  74         ring->prod_notify = prod_notify;
  75         ring->push_event = push_event;
  76         if (set_prod_notify)
  77                 qxl_ring_init_hdr(ring);
  78         spin_lock_init(&ring->lock);
  79         return ring;
  80 }
  81
  82 static int qxl_check_header(struct qxl_ring *ring)
  83 {
  84         int ret;
  85         struct qxl_ring_header *header = &(ring->ring->header);
  86         unsigned long flags;
  87         spin_lock_irqsave(&ring->lock, flags);
  88         ret = header->prod - header->cons < header->num_items;
  89         if (ret == 0)
  90                 header->notify_on_cons = header->cons + 1;
  91         spin_unlock_irqrestore(&ring->lock, flags);
  92         return ret;
  93 }
  94
  95 int qxl_check_idle(struct qxl_ring *ring)
  96 {
  97         int ret;
  98         struct qxl_ring_header *header = &(ring->ring->header);
  99         unsigned long flags;
 100         spin_lock_irqsave(&ring->lock, flags);
 101         ret = header->prod == header->cons;
 102         spin_unlock_irqrestore(&ring->lock, flags);
 103         return ret;
 104 }
 105
 106 int qxl_ring_push(struct qxl_ring *ring,
 107                   const void *new_elt, bool interruptible)
 108 {
 109         struct qxl_ring_header *header = &(ring->ring->header);
 110         uint8_t *elt;
 111         int idx, ret;
 112         unsigned long flags;
 113         spin_lock_irqsave(&ring->lock, flags);
 114         if (header->prod - header->cons == header->num_items) {
 115                 header->notify_on_cons = header->cons + 1;
 116                 mb();
 117                 spin_unlock_irqrestore(&ring->lock, flags);
 118                 if (!drm_can_sleep()) {
 119                         while (!qxl_check_header(ring))
 120                                 udelay(1);
 121                 } else {
 122                         if (interruptible) {
 123                                 ret = wait_event_interruptible(*ring->push_event,
 124                                                                qxl_check_header(ring));
 125                                 if (ret)
 126                                         return ret;
 127                         } else {
 128                                 wait_event(*ring->push_event,
 129                                            qxl_check_header(ring));
 130                         }
 131
 132                 }
 133                 spin_lock_irqsave(&ring->lock, flags);
 134         }
 135
 136         idx = header->prod & (ring->n_elements - 1);
 137         elt = ring->ring->elements + idx * ring->element_size;
 138
 139         memcpy((void *)elt, new_elt, ring->element_size);
 140
 141         header->prod++;
 142
 143         mb();
 144
 145         if (header->prod == header->notify_on_prod)
 146                 outb(0, ring->prod_notify);
 147
 148         spin_unlock_irqrestore(&ring->lock, flags);
 149         return 0;
 150 }
 151
 152 static bool qxl_ring_pop(struct qxl_ring *ring,
 153                          void *element)
 154 {
 155         volatile struct qxl_ring_header *header = &(ring->ring->header);
 156         volatile uint8_t *ring_elt;
 157         int idx;
 158         unsigned long flags;
 159         spin_lock_irqsave(&ring->lock, flags);
 160         if (header->cons == header->prod) {
 161                 header->notify_on_prod = header->cons + 1;
 162                 spin_unlock_irqrestore(&ring->lock, flags);
 163                 return false;
 164         }
 165
 166         idx = header->cons & (ring->n_elements - 1);
 167         ring_elt = ring->ring->elements + idx * ring->element_size;
 168
 169         memcpy(element, (void *)ring_elt, ring->element_size);
 170
 171         header->cons++;
 172
 173         spin_unlock_irqrestore(&ring->lock, flags);
 174         return true;
 175 }
 176
 177 int
 178 qxl_push_command_ring_release(struct qxl_device *qdev, struct qxl_release *release,
 179                               uint32_t type, bool interruptible)
 180 {
 181         struct qxl_command cmd;
 182
 183         cmd.type = type;
 184         cmd.data = qxl_bo_physical_address(qdev, release->release_bo, release->release_offset);
 185
 186         return qxl_ring_push(qdev->command_ring, &cmd, interruptible);
 187 }
 188
 189 int
 190 qxl_push_cursor_ring_release(struct qxl_device *qdev, struct qxl_release *release,
 191                              uint32_t type, bool interruptible)
 192 {
 193         struct qxl_command cmd;
 194
 195         cmd.type = type;
 196         cmd.data = qxl_bo_physical_address(qdev, release->release_bo, release->release_offset);
 197
 198         return qxl_ring_push(qdev->cursor_ring, &cmd, interruptible);
 199 }
 200
 201 bool qxl_queue_garbage_collect(struct qxl_device *qdev, bool flush)
 202 {
 203         if (!qxl_check_idle(qdev->release_ring)) {
 204                 schedule_work(&qdev->gc_work);
 205                 if (flush)
 206                         flush_work(&qdev->gc_work);
 207                 return true;
 208         }
 209         return false;
 210 }
 211
 212 int qxl_garbage_collect(struct qxl_device *qdev)
 213 {
 214         struct qxl_release *release;
 215         uint64_t id, next_id;
 216         int i = 0;
 217         union qxl_release_info *info;
 218
 219         while (qxl_ring_pop(qdev->release_ring, &id)) {
 220                 DRM_DEBUG_DRIVER("popped %lld\n", id);
 221                 while (id) {
 222                         release = qxl_release_from_id_locked(qdev, id);
 223                         if (release == NULL)
 224                                 break;
 225
 226                         info = qxl_release_map(qdev, release);
 227                         next_id = info->next;
 228                         qxl_release_unmap(qdev, release, info);
 229
 230                         DRM_DEBUG_DRIVER("popped %lld, next %lld\n", id,
 231                                          next_id);
 232
 233                         switch (release->type) {
 234                         case QXL_RELEASE_DRAWABLE:
 235                         case QXL_RELEASE_SURFACE_CMD:
 236                         case QXL_RELEASE_CURSOR_CMD:
 237                                 break;
 238                         default:
 239                                 DRM_ERROR("unexpected release type\n");
 240                                 break;
 241                         }
 242                         id = next_id;
 243
 244                         qxl_release_free(qdev, release);
 245                         ++i;
 246                 }
 247         }
 248
 249         DRM_DEBUG_DRIVER("%d\n", i);
 250
 251         return i;
 252 }
 253
 254 int qxl_alloc_bo_reserved(struct qxl_device *qdev,
 255                           struct qxl_release *release,
 256                           unsigned long size,
 257                           struct qxl_bo **_bo)
 258 {
 259         struct qxl_bo *bo;
 260         int ret;
 261
 262         ret = qxl_bo_create(qdev, size, false /* not kernel - device */,
 263                             false, QXL_GEM_DOMAIN_VRAM, NULL, &bo);
 264         if (ret) {
 265                 DRM_ERROR("failed to allocate VRAM BO\n");
 266                 return ret;
 267         }
 268         ret = qxl_release_list_add(release, bo);
 269         if (ret)
 270                 goto out_unref;
 271
 272         *_bo = bo;
 273         return 0;
 274 out_unref:
 275         qxl_bo_unref(&bo);
 276         return ret;
 277 }
 278
 279 static int wait_for_io_cmd_user(struct qxl_device *qdev, uint8_t val, long port, bool intr)
 280 {
 281         int irq_num;
 282         long addr = qdev->io_base + port;
 283         int ret;
 284
 285         mutex_lock(&qdev->async_io_mutex);
 286         irq_num = atomic_read(&qdev->irq_received_io_cmd);
 287         if (qdev->last_sent_io_cmd > irq_num) {
 288                 if (intr)
 289                         ret = wait_event_interruptible_timeout(qdev->io_cmd_event,
 290                                                                atomic_read(&qdev->irq_received_io_cmd) > irq_num, 5*HZ);
 291                 else
 292                         ret = wait_event_timeout(qdev->io_cmd_event,
 293                                                  atomic_read(&qdev->irq_received_io_cmd) > irq_num, 5*HZ);
 294                 /* 0 is timeout, just bail the "hw" has gone away */
 295                 if (ret <= 0)
 296                         goto out;
 297                 irq_num = atomic_read(&qdev->irq_received_io_cmd);
 298         }
 299         outb(val, addr);
 300         qdev->last_sent_io_cmd = irq_num + 1;
 301         if (intr)
 302                 ret = wait_event_interruptible_timeout(qdev->io_cmd_event,
 303                                                        atomic_read(&qdev->irq_received_io_cmd) > irq_num, 5*HZ);
 304         else
 305                 ret = wait_event_timeout(qdev->io_cmd_event,
 306                                          atomic_read(&qdev->irq_received_io_cmd) > irq_num, 5*HZ);
 307 out:
 308         if (ret > 0)
 309                 ret = 0;
 310         mutex_unlock(&qdev->async_io_mutex);
 311         return ret;
 312 }
 313
 314 static void wait_for_io_cmd(struct qxl_device *qdev, uint8_t val, long port)
 315 {
 316         int ret;
 317
 318 restart:
 319         ret = wait_for_io_cmd_user(qdev, val, port, false);
 320         if (ret == -ERESTARTSYS)
 321                 goto restart;
 322 }
 323
 324 int qxl_io_update_area(struct qxl_device *qdev, struct qxl_bo *surf,
 325                         const struct qxl_rect *area)
 326 {
 327         int surface_id;
 328         uint32_t surface_width, surface_height;
 329         int ret;
 330
 331         if (!surf->hw_surf_alloc)
 332                 DRM_ERROR("got io update area with no hw surface\n");
 333
 334         if (surf->is_primary)
 335                 surface_id = 0;
 336         else
 337                 surface_id = surf->surface_id;
 338         surface_width = surf->surf.width;
 339         surface_height = surf->surf.height;
 340
 341         if (area->left < 0 || area->top < 0 ||
 342             area->right > surface_width || area->bottom > surface_height)
 343                 return -EINVAL;
 344
 345         mutex_lock(&qdev->update_area_mutex);
 346         qdev->ram_header->update_area = *area;
 347         qdev->ram_header->update_surface = surface_id;
 348         ret = wait_for_io_cmd_user(qdev, 0, QXL_IO_UPDATE_AREA_ASYNC, true);
 349         mutex_unlock(&qdev->update_area_mutex);
 350         return ret;
 351 }
 352
 353 void qxl_io_notify_oom(struct qxl_device *qdev)
 354 {
 355         outb(0, qdev->io_base + QXL_IO_NOTIFY_OOM);
 356 }
 357
 358 void qxl_io_flush_release(struct qxl_device *qdev)
 359 {
 360         outb(0, qdev->io_base + QXL_IO_FLUSH_RELEASE);
 361 }
 362
 363 void qxl_io_flush_surfaces(struct qxl_device *qdev)
 364 {
 365         wait_for_io_cmd(qdev, 0, QXL_IO_FLUSH_SURFACES_ASYNC);
 366 }
 367
 368
 369 void qxl_io_destroy_primary(struct qxl_device *qdev)
 370 {
 371         wait_for_io_cmd(qdev, 0, QXL_IO_DESTROY_PRIMARY_ASYNC);
 372         qdev->primary_created = false;
 373 }
 374
 375 void qxl_io_create_primary(struct qxl_device *qdev,
 376                            unsigned offset, struct qxl_bo *bo)
 377 {
 378         struct qxl_surface_create *create;
 379
 380         DRM_DEBUG_DRIVER("qdev %p, ram_header %p\n", qdev, qdev->ram_header);
 381         create = &qdev->ram_header->create_surface;
 382         create->format = bo->surf.format;
 383         create->width = bo->surf.width;
 384         create->height = bo->surf.height;
 385         create->stride = bo->surf.stride;
 386         if (bo->shadow) {
 387                 create->mem = qxl_bo_physical_address(qdev, bo->shadow, offset);
 388         } else {
 389                 create->mem = qxl_bo_physical_address(qdev, bo, offset);
 390         }
 391
 392         DRM_DEBUG_DRIVER("mem = %llx, from %p\n", create->mem, bo->kptr);
 393
 394         create->flags = QXL_SURF_FLAG_KEEP_DATA;
 395         create->type = QXL_SURF_TYPE_PRIMARY;
 396
 397         wait_for_io_cmd(qdev, 0, QXL_IO_CREATE_PRIMARY_ASYNC);
 398         qdev->primary_created = true;
 399 }
 400
 401 void qxl_io_memslot_add(struct qxl_device *qdev, uint8_t id)
 402 {
 403         DRM_DEBUG_DRIVER("qxl_memslot_add %d\n", id);
 404         wait_for_io_cmd(qdev, id, QXL_IO_MEMSLOT_ADD_ASYNC);
 405 }
 406
 407 void qxl_io_reset(struct qxl_device *qdev)
 408 {
 409         outb(0, qdev->io_base + QXL_IO_RESET);
 410 }
 411
 412 void qxl_io_monitors_config(struct qxl_device *qdev)
 413 {
 414         wait_for_io_cmd(qdev, 0, QXL_IO_MONITORS_CONFIG_ASYNC);
 415 }
 416
 417 int qxl_surface_id_alloc(struct qxl_device *qdev,
 418                       struct qxl_bo *surf)
 419 {
 420         uint32_t handle;
 421         int idr_ret;
 422         int count = 0;
 423 again:
 424         idr_preload(GFP_ATOMIC);
 425         spin_lock(&qdev->surf_id_idr_lock);
 426         idr_ret = idr_alloc(&qdev->surf_id_idr, NULL, 1, 0, GFP_NOWAIT);
 427         spin_unlock(&qdev->surf_id_idr_lock);
 428         idr_preload_end();
 429         if (idr_ret < 0)
 430                 return idr_ret;
 431         handle = idr_ret;
 432
 433         if (handle >= qdev->rom->n_surfaces) {
 434                 count++;
 435                 spin_lock(&qdev->surf_id_idr_lock);
 436                 idr_remove(&qdev->surf_id_idr, handle);
 437                 spin_unlock(&qdev->surf_id_idr_lock);
 438                 qxl_reap_surface_id(qdev, 2);
 439                 goto again;
 440         }
 441         surf->surface_id = handle;
 442
 443         spin_lock(&qdev->surf_id_idr_lock);
 444         qdev->last_alloced_surf_id = handle;
 445         spin_unlock(&qdev->surf_id_idr_lock);
 446         return 0;
 447 }
 448
 449 void qxl_surface_id_dealloc(struct qxl_device *qdev,
 450                             uint32_t surface_id)
 451 {
 452         spin_lock(&qdev->surf_id_idr_lock);
 453         idr_remove(&qdev->surf_id_idr, surface_id);
 454         spin_unlock(&qdev->surf_id_idr_lock);
 455 }
 456
 457 int qxl_hw_surface_alloc(struct qxl_device *qdev,
 458                          struct qxl_bo *surf,
 459                          struct ttm_mem_reg *new_mem)
 460 {
 461         struct qxl_surface_cmd *cmd;
 462         struct qxl_release *release;
 463         int ret;
 464
 465         if (surf->hw_surf_alloc)
 466                 return 0;
 467
 468         ret = qxl_alloc_surface_release_reserved(qdev, QXL_SURFACE_CMD_CREATE,
 469                                                  NULL,
 470                                                  &release);
 471         if (ret)
 472                 return ret;
 473
 474         ret = qxl_release_reserve_list(release, true);
 475         if (ret)
 476                 return ret;
 477
 478         cmd = (struct qxl_surface_cmd *)qxl_release_map(qdev, release);
 479         cmd->type = QXL_SURFACE_CMD_CREATE;
 480         cmd->flags = QXL_SURF_FLAG_KEEP_DATA;
 481         cmd->u.surface_create.format = surf->surf.format;
 482         cmd->u.surface_create.width = surf->surf.width;
 483         cmd->u.surface_create.height = surf->surf.height;
 484         cmd->u.surface_create.stride = surf->surf.stride;
 485         if (new_mem) {
 486                 int slot_id = surf->type == QXL_GEM_DOMAIN_VRAM ? qdev->main_mem_slot : qdev->surfaces_mem_slot;
 487                 struct qxl_memslot *slot = &(qdev->mem_slots[slot_id]);
 488
 489                 /* TODO - need to hold one of the locks to read tbo.offset */
 490                 cmd->u.surface_create.data = slot->high_bits;
 491
 492                 cmd->u.surface_create.data |= (new_mem->start << PAGE_SHIFT) + surf->tbo.bdev->man[new_mem->mem_type].gpu_offset;
 493         } else
 494                 cmd->u.surface_create.data = qxl_bo_physical_address(qdev, surf, 0);
 495         cmd->surface_id = surf->surface_id;
 496         qxl_release_unmap(qdev, release, &cmd->release_info);
 497
 498         surf->surf_create = release;
 499
 500         /* no need to add a release to the fence for this surface bo,
 501            since it is only released when we ask to destroy the surface
 502            and it would never signal otherwise */
 503         qxl_push_command_ring_release(qdev, release, QXL_CMD_SURFACE, false);
 504         qxl_release_fence_buffer_objects(release);
 505
 506         surf->hw_surf_alloc = true;
 507         spin_lock(&qdev->surf_id_idr_lock);
 508         idr_replace(&qdev->surf_id_idr, surf, surf->surface_id);
 509         spin_unlock(&qdev->surf_id_idr_lock);
 510         return 0;
 511 }
 512
 513 int qxl_hw_surface_dealloc(struct qxl_device *qdev,
 514                            struct qxl_bo *surf)
 515 {
 516         struct qxl_surface_cmd *cmd;
 517         struct qxl_release *release;
 518         int ret;
 519         int id;
 520
 521         if (!surf->hw_surf_alloc)
 522                 return 0;
 523
 524         ret = qxl_alloc_surface_release_reserved(qdev, QXL_SURFACE_CMD_DESTROY,
 525                                                  surf->surf_create,
 526                                                  &release);
 527         if (ret)
 528                 return ret;
 529
 530         surf->surf_create = NULL;
 531         /* remove the surface from the idr, but not the surface id yet */
 532         spin_lock(&qdev->surf_id_idr_lock);
 533         idr_replace(&qdev->surf_id_idr, NULL, surf->surface_id);
 534         spin_unlock(&qdev->surf_id_idr_lock);
 535         surf->hw_surf_alloc = false;
 536
 537         id = surf->surface_id;
 538         surf->surface_id = 0;
 539
 540         release->surface_release_id = id;
 541         cmd = (struct qxl_surface_cmd *)qxl_release_map(qdev, release);
 542         cmd->type = QXL_SURFACE_CMD_DESTROY;
 543         cmd->surface_id = id;
 544         qxl_release_unmap(qdev, release, &cmd->release_info);
 545
 546         qxl_push_command_ring_release(qdev, release, QXL_CMD_SURFACE, false);
 547
 548         qxl_release_fence_buffer_objects(release);
 549
 550         return 0;
 551 }
 552
 553 static int qxl_update_surface(struct qxl_device *qdev, struct qxl_bo *surf)
 554 {
 555         struct qxl_rect rect;
 556         int ret;
 557
 558         /* if we are evicting, we need to make sure the surface is up
 559            to date */
 560         rect.left = 0;
 561         rect.right = surf->surf.width;
 562         rect.top = 0;
 563         rect.bottom = surf->surf.height;
 564 retry:
 565         ret = qxl_io_update_area(qdev, surf, &rect);
 566         if (ret == -ERESTARTSYS)
 567                 goto retry;
 568         return ret;
 569 }
 570
 571 static void qxl_surface_evict_locked(struct qxl_device *qdev, struct qxl_bo *surf, bool do_update_area)
 572 {
 573         /* no need to update area if we are just freeing the surface normally */
 574         if (do_update_area)
 575                 qxl_update_surface(qdev, surf);
 576
 577         /* nuke the surface id at the hw */
 578         qxl_hw_surface_dealloc(qdev, surf);
 579 }
 580
 581 void qxl_surface_evict(struct qxl_device *qdev, struct qxl_bo *surf, bool do_update_area)
 582 {
 583         mutex_lock(&qdev->surf_evict_mutex);
 584         qxl_surface_evict_locked(qdev, surf, do_update_area);
 585         mutex_unlock(&qdev->surf_evict_mutex);
 586 }
 587
 588 static int qxl_reap_surf(struct qxl_device *qdev, struct qxl_bo *surf, bool stall)
 589 {
 590         int ret;
 591
 592         ret = qxl_bo_reserve(surf, false);
 593         if (ret)
 594                 return ret;
 595
 596         if (stall)
 597                 mutex_unlock(&qdev->surf_evict_mutex);
 598
 599         ret = ttm_bo_wait(&surf->tbo, true, !stall);
 600
 601         if (stall)
 602                 mutex_lock(&qdev->surf_evict_mutex);
 603         if (ret) {
 604                 qxl_bo_unreserve(surf);
 605                 return ret;
 606         }
 607
 608         qxl_surface_evict_locked(qdev, surf, true);
 609         qxl_bo_unreserve(surf);
 610         return 0;
 611 }
 612
 613 static int qxl_reap_surface_id(struct qxl_device *qdev, int max_to_reap)
 614 {
 615         int num_reaped = 0;
 616         int i, ret;
 617         bool stall = false;
 618         int start = 0;
 619
 620         mutex_lock(&qdev->surf_evict_mutex);
 621 again:
 622
 623         spin_lock(&qdev->surf_id_idr_lock);
 624         start = qdev->last_alloced_surf_id + 1;
 625         spin_unlock(&qdev->surf_id_idr_lock);
 626
 627         for (i = start; i < start + qdev->rom->n_surfaces; i++) {
 628                 void *objptr;
 629                 int surfid = i % qdev->rom->n_surfaces;
 630
 631                 /* this avoids the case where the objects is in the
 632                    idr but has been evicted half way - its makes
 633                    the idr lookup atomic with the eviction */
 634                 spin_lock(&qdev->surf_id_idr_lock);
 635                 objptr = idr_find(&qdev->surf_id_idr, surfid);
 636                 spin_unlock(&qdev->surf_id_idr_lock);
 637
 638                 if (!objptr)
 639                         continue;
 640
 641                 ret = qxl_reap_surf(qdev, objptr, stall);
 642                 if (ret == 0)
 643                         num_reaped++;
 644                 if (num_reaped >= max_to_reap)
 645                         break;
 646         }
 647         if (num_reaped == 0 && stall == false) {
 648                 stall = true;
 649                 goto again;
 650         }
 651
 652         mutex_unlock(&qdev->surf_evict_mutex);
 653         if (num_reaped) {
 654                 usleep_range(500, 1000);
 655                 qxl_queue_garbage_collect(qdev, true);
 656         }
 657
 658         return 0;
 659 }