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
  88         spin_lock_irqsave(&ring->lock, flags);
  89         ret = header->prod - header->cons < header->num_items;
  90         if (ret == 0)
  91                 header->notify_on_cons = header->cons + 1;
  92         spin_unlock_irqrestore(&ring->lock, flags);
  93         return ret;
  94 }
  95
  96 int qxl_check_idle(struct qxl_ring *ring)
  97 {
  98         int ret;
  99         struct qxl_ring_header *header = &(ring->ring->header);
 100         unsigned long flags;
 101
 102         spin_lock_irqsave(&ring->lock, flags);
 103         ret = header->prod == header->cons;
 104         spin_unlock_irqrestore(&ring->lock, flags);
 105         return ret;
 106 }
 107
 108 int qxl_ring_push(struct qxl_ring *ring,
 109                   const void *new_elt, bool interruptible)
 110 {
 111         struct qxl_ring_header *header = &(ring->ring->header);
 112         uint8_t *elt;
 113         int idx, ret;
 114         unsigned long flags;
 115
 116         spin_lock_irqsave(&ring->lock, flags);
 117         if (header->prod - header->cons == header->num_items) {
 118                 header->notify_on_cons = header->cons + 1;
 119                 mb();
 120                 spin_unlock_irqrestore(&ring->lock, flags);
 121                 if (!drm_can_sleep()) {
 122                         while (!qxl_check_header(ring))
 123                                 udelay(1);
 124                 } else {
 125                         if (interruptible) {
 126                                 ret = wait_event_interruptible(*ring->push_event,
 127                                                                qxl_check_header(ring));
 128                                 if (ret)
 129                                         return ret;
 130                         } else {
 131                                 wait_event(*ring->push_event,
 132                                            qxl_check_header(ring));
 133                         }
 134
 135                 }
 136                 spin_lock_irqsave(&ring->lock, flags);
 137         }
 138
 139         idx = header->prod & (ring->n_elements - 1);
 140         elt = ring->ring->elements + idx * ring->element_size;
 141
 142         memcpy((void *)elt, new_elt, ring->element_size);
 143
 144         header->prod++;
 145
 146         mb();
 147
 148         if (header->prod == header->notify_on_prod)
 149                 outb(0, ring->prod_notify);
 150
 151         spin_unlock_irqrestore(&ring->lock, flags);
 152         return 0;
 153 }
 154
 155 static bool qxl_ring_pop(struct qxl_ring *ring,
 156                          void *element)
 157 {
 158         volatile struct qxl_ring_header *header = &(ring->ring->header);
 159         volatile uint8_t *ring_elt;
 160         int idx;
 161         unsigned long flags;
 162
 163         spin_lock_irqsave(&ring->lock, flags);
 164         if (header->cons == header->prod) {
 165                 header->notify_on_prod = header->cons + 1;
 166                 spin_unlock_irqrestore(&ring->lock, flags);
 167                 return false;
 168         }
 169
 170         idx = header->cons & (ring->n_elements - 1);
 171         ring_elt = ring->ring->elements + idx * ring->element_size;
 172
 173         memcpy(element, (void *)ring_elt, ring->element_size);
 174
 175         header->cons++;
 176
 177         spin_unlock_irqrestore(&ring->lock, flags);
 178         return true;
 179 }
 180
 181 int
 182 qxl_push_command_ring_release(struct qxl_device *qdev, struct qxl_release *release,
 183                               uint32_t type, bool interruptible)
 184 {
 185         struct qxl_command cmd;
 186
 187         cmd.type = type;
 188         cmd.data = qxl_bo_physical_address(qdev, release->release_bo, release->release_offset);
 189
 190         return qxl_ring_push(qdev->command_ring, &cmd, interruptible);
 191 }
 192
 193 int
 194 qxl_push_cursor_ring_release(struct qxl_device *qdev, struct qxl_release *release,
 195                              uint32_t type, bool interruptible)
 196 {
 197         struct qxl_command cmd;
 198
 199         cmd.type = type;
 200         cmd.data = qxl_bo_physical_address(qdev, release->release_bo, release->release_offset);
 201
 202         return qxl_ring_push(qdev->cursor_ring, &cmd, interruptible);
 203 }
 204
 205 bool qxl_queue_garbage_collect(struct qxl_device *qdev, bool flush)
 206 {
 207         if (!qxl_check_idle(qdev->release_ring)) {
 208                 schedule_work(&qdev->gc_work);
 209                 if (flush)
 210                         flush_work(&qdev->gc_work);
 211                 return true;
 212         }
 213         return false;
 214 }
 215
 216 int qxl_garbage_collect(struct qxl_device *qdev)
 217 {
 218         struct qxl_release *release;
 219         uint64_t id, next_id;
 220         int i = 0;
 221         union qxl_release_info *info;
 222
 223         while (qxl_ring_pop(qdev->release_ring, &id)) {
 224                 DRM_DEBUG_DRIVER("popped %lld\n", id);
 225                 while (id) {
 226                         release = qxl_release_from_id_locked(qdev, id);
 227                         if (release == NULL)
 228                                 break;
 229
 230                         info = qxl_release_map(qdev, release);
 231                         next_id = info->next;
 232                         qxl_release_unmap(qdev, release, info);
 233
 234                         DRM_DEBUG_DRIVER("popped %lld, next %lld\n", id,
 235                                          next_id);
 236
 237                         switch (release->type) {
 238                         case QXL_RELEASE_DRAWABLE:
 239                         case QXL_RELEASE_SURFACE_CMD:
 240                         case QXL_RELEASE_CURSOR_CMD:
 241                                 break;
 242                         default:
 243                                 DRM_ERROR("unexpected release type\n");
 244                                 break;
 245                         }
 246                         id = next_id;
 247
 248                         qxl_release_free(qdev, release);
 249                         ++i;
 250                 }
 251         }
 252
 253         DRM_DEBUG_DRIVER("%d\n", i);
 254
 255         return i;
 256 }
 257
 258 int qxl_alloc_bo_reserved(struct qxl_device *qdev,
 259                           struct qxl_release *release,
 260                           unsigned long size,
 261                           struct qxl_bo **_bo)
 262 {
 263         struct qxl_bo *bo;
 264         int ret;
 265
 266         ret = qxl_bo_create(qdev, size, false /* not kernel - device */,
 267                             false, QXL_GEM_DOMAIN_VRAM, NULL, &bo);
 268         if (ret) {
 269                 DRM_ERROR("failed to allocate VRAM BO\n");
 270                 return ret;
 271         }
 272         ret = qxl_release_list_add(release, bo);
 273         if (ret)
 274                 goto out_unref;
 275
 276         *_bo = bo;
 277         return 0;
 278 out_unref:
 279         qxl_bo_unref(&bo);
 280         return ret;
 281 }
 282
 283 static int wait_for_io_cmd_user(struct qxl_device *qdev, uint8_t val, long port, bool intr)
 284 {
 285         int irq_num;
 286         long addr = qdev->io_base + port;
 287         int ret;
 288
 289         mutex_lock(&qdev->async_io_mutex);
 290         irq_num = atomic_read(&qdev->irq_received_io_cmd);
 291         if (qdev->last_sent_io_cmd > irq_num) {
 292                 if (intr)
 293                         ret = wait_event_interruptible_timeout(qdev->io_cmd_event,
 294                                                                atomic_read(&qdev->irq_received_io_cmd) > irq_num, 5*HZ);
 295                 else
 296                         ret = wait_event_timeout(qdev->io_cmd_event,
 297                                                  atomic_read(&qdev->irq_received_io_cmd) > irq_num, 5*HZ);
 298                 /* 0 is timeout, just bail the "hw" has gone away */
 299                 if (ret <= 0)
 300                         goto out;
 301                 irq_num = atomic_read(&qdev->irq_received_io_cmd);
 302         }
 303         outb(val, addr);
 304         qdev->last_sent_io_cmd = irq_num + 1;
 305         if (intr)
 306                 ret = wait_event_interruptible_timeout(qdev->io_cmd_event,
 307                                                        atomic_read(&qdev->irq_received_io_cmd) > irq_num, 5*HZ);
 308         else
 309                 ret = wait_event_timeout(qdev->io_cmd_event,
 310                                          atomic_read(&qdev->irq_received_io_cmd) > irq_num, 5*HZ);
 311 out:
 312         if (ret > 0)
 313                 ret = 0;
 314         mutex_unlock(&qdev->async_io_mutex);
 315         return ret;
 316 }
 317
 318 static void wait_for_io_cmd(struct qxl_device *qdev, uint8_t val, long port)
 319 {
 320         int ret;
 321
 322 restart:
 323         ret = wait_for_io_cmd_user(qdev, val, port, false);
 324         if (ret == -ERESTARTSYS)
 325                 goto restart;
 326 }
 327
 328 int qxl_io_update_area(struct qxl_device *qdev, struct qxl_bo *surf,
 329                         const struct qxl_rect *area)
 330 {
 331         int surface_id;
 332         uint32_t surface_width, surface_height;
 333         int ret;
 334
 335         if (!surf->hw_surf_alloc)
 336                 DRM_ERROR("got io update area with no hw surface\n");
 337
 338         if (surf->is_primary)
 339                 surface_id = 0;
 340         else
 341                 surface_id = surf->surface_id;
 342         surface_width = surf->surf.width;
 343         surface_height = surf->surf.height;
 344
 345         if (area->left < 0 || area->top < 0 ||
 346             area->right > surface_width || area->bottom > surface_height)
 347                 return -EINVAL;
 348
 349         mutex_lock(&qdev->update_area_mutex);
 350         qdev->ram_header->update_area = *area;
 351         qdev->ram_header->update_surface = surface_id;
 352         ret = wait_for_io_cmd_user(qdev, 0, QXL_IO_UPDATE_AREA_ASYNC, true);
 353         mutex_unlock(&qdev->update_area_mutex);
 354         return ret;
 355 }
 356
 357 void qxl_io_notify_oom(struct qxl_device *qdev)
 358 {
 359         outb(0, qdev->io_base + QXL_IO_NOTIFY_OOM);
 360 }
 361
 362 void qxl_io_flush_release(struct qxl_device *qdev)
 363 {
 364         outb(0, qdev->io_base + QXL_IO_FLUSH_RELEASE);
 365 }
 366
 367 void qxl_io_flush_surfaces(struct qxl_device *qdev)
 368 {
 369         wait_for_io_cmd(qdev, 0, QXL_IO_FLUSH_SURFACES_ASYNC);
 370 }
 371
 372 void qxl_io_destroy_primary(struct qxl_device *qdev)
 373 {
 374         wait_for_io_cmd(qdev, 0, QXL_IO_DESTROY_PRIMARY_ASYNC);
 375         qdev->primary_created = false;
 376 }
 377
 378 void qxl_io_create_primary(struct qxl_device *qdev,
 379                            unsigned int offset, struct qxl_bo *bo)
 380 {
 381         struct qxl_surface_create *create;
 382
 383         DRM_DEBUG_DRIVER("qdev %p, ram_header %p\n", qdev, qdev->ram_header);
 384         create = &qdev->ram_header->create_surface;
 385         create->format = bo->surf.format;
 386         create->width = bo->surf.width;
 387         create->height = bo->surf.height;
 388         create->stride = bo->surf.stride;
 389         if (bo->shadow) {
 390                 create->mem = qxl_bo_physical_address(qdev, bo->shadow, offset);
 391         } else {
 392                 create->mem = qxl_bo_physical_address(qdev, bo, offset);
 393         }
 394
 395         DRM_DEBUG_DRIVER("mem = %llx, from %p\n", create->mem, bo->kptr);
 396
 397         create->flags = QXL_SURF_FLAG_KEEP_DATA;
 398         create->type = QXL_SURF_TYPE_PRIMARY;
 399
 400         wait_for_io_cmd(qdev, 0, QXL_IO_CREATE_PRIMARY_ASYNC);
 401         qdev->primary_created = true;
 402 }
 403
 404 void qxl_io_memslot_add(struct qxl_device *qdev, uint8_t id)
 405 {
 406         DRM_DEBUG_DRIVER("qxl_memslot_add %d\n", id);
 407         wait_for_io_cmd(qdev, id, QXL_IO_MEMSLOT_ADD_ASYNC);
 408 }
 409
 410 void qxl_io_reset(struct qxl_device *qdev)
 411 {
 412         outb(0, qdev->io_base + QXL_IO_RESET);
 413 }
 414
 415 void qxl_io_monitors_config(struct qxl_device *qdev)
 416 {
 417         wait_for_io_cmd(qdev, 0, QXL_IO_MONITORS_CONFIG_ASYNC);
 418 }
 419
 420 int qxl_surface_id_alloc(struct qxl_device *qdev,
 421                       struct qxl_bo *surf)
 422 {
 423         uint32_t handle;
 424         int idr_ret;
 425         int count = 0;
 426 again:
 427         idr_preload(GFP_ATOMIC);
 428         spin_lock(&qdev->surf_id_idr_lock);
 429         idr_ret = idr_alloc(&qdev->surf_id_idr, NULL, 1, 0, GFP_NOWAIT);
 430         spin_unlock(&qdev->surf_id_idr_lock);
 431         idr_preload_end();
 432         if (idr_ret < 0)
 433                 return idr_ret;
 434         handle = idr_ret;
 435
 436         if (handle >= qdev->rom->n_surfaces) {
 437                 count++;
 438                 spin_lock(&qdev->surf_id_idr_lock);
 439                 idr_remove(&qdev->surf_id_idr, handle);
 440                 spin_unlock(&qdev->surf_id_idr_lock);
 441                 qxl_reap_surface_id(qdev, 2);
 442                 goto again;
 443         }
 444         surf->surface_id = handle;
 445
 446         spin_lock(&qdev->surf_id_idr_lock);
 447         qdev->last_alloced_surf_id = handle;
 448         spin_unlock(&qdev->surf_id_idr_lock);
 449         return 0;
 450 }
 451
 452 void qxl_surface_id_dealloc(struct qxl_device *qdev,
 453                             uint32_t surface_id)
 454 {
 455         spin_lock(&qdev->surf_id_idr_lock);
 456         idr_remove(&qdev->surf_id_idr, surface_id);
 457         spin_unlock(&qdev->surf_id_idr_lock);
 458 }
 459
 460 int qxl_hw_surface_alloc(struct qxl_device *qdev,
 461                          struct qxl_bo *surf,
 462                          struct ttm_mem_reg *new_mem)
 463 {
 464         struct qxl_surface_cmd *cmd;
 465         struct qxl_release *release;
 466         int ret;
 467
 468         if (surf->hw_surf_alloc)
 469                 return 0;
 470
 471         ret = qxl_alloc_surface_release_reserved(qdev, QXL_SURFACE_CMD_CREATE,
 472                                                  NULL,
 473                                                  &release);
 474         if (ret)
 475                 return ret;
 476
 477         ret = qxl_release_reserve_list(release, true);
 478         if (ret)
 479                 return ret;
 480
 481         cmd = (struct qxl_surface_cmd *)qxl_release_map(qdev, release);
 482         cmd->type = QXL_SURFACE_CMD_CREATE;
 483         cmd->flags = QXL_SURF_FLAG_KEEP_DATA;
 484         cmd->u.surface_create.format = surf->surf.format;
 485         cmd->u.surface_create.width = surf->surf.width;
 486         cmd->u.surface_create.height = surf->surf.height;
 487         cmd->u.surface_create.stride = surf->surf.stride;
 488         if (new_mem) {
 489                 int slot_id = surf->type == QXL_GEM_DOMAIN_VRAM ? qdev->main_mem_slot : qdev->surfaces_mem_slot;
 490                 struct qxl_memslot *slot = &(qdev->mem_slots[slot_id]);
 491
 492                 /* TODO - need to hold one of the locks to read tbo.offset */
 493                 cmd->u.surface_create.data = slot->high_bits;
 494
 495                 cmd->u.surface_create.data |= (new_mem->start << PAGE_SHIFT) + surf->tbo.bdev->man[new_mem->mem_type].gpu_offset;
 496         } else
 497                 cmd->u.surface_create.data = qxl_bo_physical_address(qdev, surf, 0);
 498         cmd->surface_id = surf->surface_id;
 499         qxl_release_unmap(qdev, release, &cmd->release_info);
 500
 501         surf->surf_create = release;
 502
 503         /* no need to add a release to the fence for this surface bo,
 504            since it is only released when we ask to destroy the surface
 505            and it would never signal otherwise */
 506         qxl_push_command_ring_release(qdev, release, QXL_CMD_SURFACE, false);
 507         qxl_release_fence_buffer_objects(release);
 508
 509         surf->hw_surf_alloc = true;
 510         spin_lock(&qdev->surf_id_idr_lock);
 511         idr_replace(&qdev->surf_id_idr, surf, surf->surface_id);
 512         spin_unlock(&qdev->surf_id_idr_lock);
 513         return 0;
 514 }
 515
 516 int qxl_hw_surface_dealloc(struct qxl_device *qdev,
 517                            struct qxl_bo *surf)
 518 {
 519         struct qxl_surface_cmd *cmd;
 520         struct qxl_release *release;
 521         int ret;
 522         int id;
 523
 524         if (!surf->hw_surf_alloc)
 525                 return 0;
 526
 527         ret = qxl_alloc_surface_release_reserved(qdev, QXL_SURFACE_CMD_DESTROY,
 528                                                  surf->surf_create,
 529                                                  &release);
 530         if (ret)
 531                 return ret;
 532
 533         surf->surf_create = NULL;
 534         /* remove the surface from the idr, but not the surface id yet */
 535         spin_lock(&qdev->surf_id_idr_lock);
 536         idr_replace(&qdev->surf_id_idr, NULL, surf->surface_id);
 537         spin_unlock(&qdev->surf_id_idr_lock);
 538         surf->hw_surf_alloc = false;
 539
 540         id = surf->surface_id;
 541         surf->surface_id = 0;
 542
 543         release->surface_release_id = id;
 544         cmd = (struct qxl_surface_cmd *)qxl_release_map(qdev, release);
 545         cmd->type = QXL_SURFACE_CMD_DESTROY;
 546         cmd->surface_id = id;
 547         qxl_release_unmap(qdev, release, &cmd->release_info);
 548
 549         qxl_push_command_ring_release(qdev, release, QXL_CMD_SURFACE, false);
 550
 551         qxl_release_fence_buffer_objects(release);
 552
 553         return 0;
 554 }
 555
 556 static int qxl_update_surface(struct qxl_device *qdev, struct qxl_bo *surf)
 557 {
 558         struct qxl_rect rect;
 559         int ret;
 560
 561         /* if we are evicting, we need to make sure the surface is up
 562            to date */
 563         rect.left = 0;
 564         rect.right = surf->surf.width;
 565         rect.top = 0;
 566         rect.bottom = surf->surf.height;
 567 retry:
 568         ret = qxl_io_update_area(qdev, surf, &rect);
 569         if (ret == -ERESTARTSYS)
 570                 goto retry;
 571         return ret;
 572 }
 573
 574 static void qxl_surface_evict_locked(struct qxl_device *qdev, struct qxl_bo *surf, bool do_update_area)
 575 {
 576         /* no need to update area if we are just freeing the surface normally */
 577         if (do_update_area)
 578                 qxl_update_surface(qdev, surf);
 579
 580         /* nuke the surface id at the hw */
 581         qxl_hw_surface_dealloc(qdev, surf);
 582 }
 583
 584 void qxl_surface_evict(struct qxl_device *qdev, struct qxl_bo *surf, bool do_update_area)
 585 {
 586         mutex_lock(&qdev->surf_evict_mutex);
 587         qxl_surface_evict_locked(qdev, surf, do_update_area);
 588         mutex_unlock(&qdev->surf_evict_mutex);
 589 }
 590
 591 static int qxl_reap_surf(struct qxl_device *qdev, struct qxl_bo *surf, bool stall)
 592 {
 593         int ret;
 594
 595         ret = qxl_bo_reserve(surf, false);
 596         if (ret)
 597                 return ret;
 598
 599         if (stall)
 600                 mutex_unlock(&qdev->surf_evict_mutex);
 601
 602         ret = ttm_bo_wait(&surf->tbo, true, !stall);
 603
 604         if (stall)
 605                 mutex_lock(&qdev->surf_evict_mutex);
 606         if (ret) {
 607                 qxl_bo_unreserve(surf);
 608                 return ret;
 609         }
 610
 611         qxl_surface_evict_locked(qdev, surf, true);
 612         qxl_bo_unreserve(surf);
 613         return 0;
 614 }
 615
 616 static int qxl_reap_surface_id(struct qxl_device *qdev, int max_to_reap)
 617 {
 618         int num_reaped = 0;
 619         int i, ret;
 620         bool stall = false;
 621         int start = 0;
 622
 623         mutex_lock(&qdev->surf_evict_mutex);
 624 again:
 625
 626         spin_lock(&qdev->surf_id_idr_lock);
 627         start = qdev->last_alloced_surf_id + 1;
 628         spin_unlock(&qdev->surf_id_idr_lock);
 629
 630         for (i = start; i < start + qdev->rom->n_surfaces; i++) {
 631                 void *objptr;
 632                 int surfid = i % qdev->rom->n_surfaces;
 633
 634                 /* this avoids the case where the objects is in the
 635                    idr but has been evicted half way - its makes
 636                    the idr lookup atomic with the eviction */
 637                 spin_lock(&qdev->surf_id_idr_lock);
 638                 objptr = idr_find(&qdev->surf_id_idr, surfid);
 639                 spin_unlock(&qdev->surf_id_idr_lock);
 640
 641                 if (!objptr)
 642                         continue;
 643
 644                 ret = qxl_reap_surf(qdev, objptr, stall);
 645                 if (ret == 0)
 646                         num_reaped++;
 647                 if (num_reaped >= max_to_reap)
 648                         break;
 649         }
 650         if (num_reaped == 0 && stall == false) {
 651                 stall = true;
 652                 goto again;
 653         }
 654
 655         mutex_unlock(&qdev->surf_evict_mutex);
 656         if (num_reaped) {
 657                 usleep_range(500, 1000);
 658                 qxl_queue_garbage_collect(qdev, true);
 659         }
 660
 661         return 0;
 662 }