drivers/gpu/drm/ttm/ttm_bo_util.c

   1 /* SPDX-License-Identifier: GPL-2.0 OR MIT */
   2 /**************************************************************************
   3  *
   4  * Copyright (c) 2007-2009 VMware, Inc., Palo Alto, CA., USA
   5  * All Rights Reserved.
   6  *
   7  * Permission is hereby granted, free of charge, to any person obtaining a
   8  * copy of this software and associated documentation files (the
   9  * "Software"), to deal in the Software without restriction, including
  10  * without limitation the rights to use, copy, modify, merge, publish,
  11  * distribute, sub license, and/or sell copies of the Software, and to
  12  * permit persons to whom the Software is furnished to do so, subject to
  13  * the following conditions:
  14  *
  15  * The above copyright notice and this permission notice (including the
  16  * next paragraph) shall be included in all copies or substantial portions
  17  * of the Software.
  18  *
  19  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
  20  * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
  21  * FITNESS FOR A PARTICULAR PURPOSE AND NON-INFRINGEMENT. IN NO EVENT SHALL
  22  * THE COPYRIGHT HOLDERS, AUTHORS AND/OR ITS SUPPLIERS BE LIABLE FOR ANY CLAIM,
  23  * DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR
  24  * OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE
  25  * USE OR OTHER DEALINGS IN THE SOFTWARE.
  26  *
  27  **************************************************************************/
  28 /*
  29  * Authors: Thomas Hellstrom <thellstrom-at-vmware-dot-com>
  30  */
  31
  32 #include <drm/ttm/ttm_bo_driver.h>
  33 #include <drm/ttm/ttm_placement.h>
  34 #include <drm/drm_vma_manager.h>
  35 #include <linux/io.h>
  36 #include <linux/highmem.h>
  37 #include <linux/wait.h>
  38 #include <linux/slab.h>
  39 #include <linux/vmalloc.h>
  40 #include <linux/module.h>
  41 #include <linux/dma-resv.h>
  42
  43 struct ttm_transfer_obj {
  44         struct ttm_buffer_object base;
  45         struct ttm_buffer_object *bo;
  46 };
  47
  48 void ttm_bo_free_old_node(struct ttm_buffer_object *bo)
  49 {
  50         ttm_resource_free(bo, &bo->mem);
  51 }
  52
  53 int ttm_bo_move_ttm(struct ttm_buffer_object *bo,
  54                    struct ttm_operation_ctx *ctx,
  55                     struct ttm_resource *new_mem)
  56 {
  57         struct ttm_tt *ttm = bo->ttm;
  58         struct ttm_resource *old_mem = &bo->mem;
  59         int ret;
  60
  61         if (old_mem->mem_type != TTM_PL_SYSTEM) {
  62                 ret = ttm_bo_wait(bo, ctx->interruptible, ctx->no_wait_gpu);
  63
  64                 if (unlikely(ret != 0)) {
  65                         if (ret != -ERESTARTSYS)
  66                                 pr_err("Failed to expire sync object before unbinding TTM\n");
  67                         return ret;
  68                 }
  69
  70                 ttm_bo_tt_unbind(bo);
  71                 ttm_bo_free_old_node(bo);
  72                 old_mem->mem_type = TTM_PL_SYSTEM;
  73         }
  74
  75         ret = ttm_tt_set_placement_caching(ttm, new_mem->placement);
  76         if (unlikely(ret != 0))
  77                 return ret;
  78
  79         if (new_mem->mem_type != TTM_PL_SYSTEM) {
  80
  81                 ret = ttm_tt_populate(bo->bdev, ttm, ctx);
  82                 if (unlikely(ret != 0))
  83                         return ret;
  84
  85                 ret = ttm_bo_tt_bind(bo, new_mem);
  86                 if (unlikely(ret != 0))
  87                         return ret;
  88         }
  89
  90         *old_mem = *new_mem;
  91         new_mem->mm_node = NULL;
  92
  93         return 0;
  94 }
  95 EXPORT_SYMBOL(ttm_bo_move_ttm);
  96
  97 int ttm_mem_io_reserve(struct ttm_bo_device *bdev,
  98                        struct ttm_resource *mem)
  99 {
 100         if (mem->bus.offset || mem->bus.addr)
 101                 return 0;
 102
 103         mem->bus.is_iomem = false;
 104         if (!bdev->driver->io_mem_reserve)
 105                 return 0;
 106
 107         return bdev->driver->io_mem_reserve(bdev, mem);
 108 }
 109
 110 void ttm_mem_io_free(struct ttm_bo_device *bdev,
 111                      struct ttm_resource *mem)
 112 {
 113         if (!mem->bus.offset && !mem->bus.addr)
 114                 return;
 115
 116         if (bdev->driver->io_mem_free)
 117                 bdev->driver->io_mem_free(bdev, mem);
 118
 119         mem->bus.offset = 0;
 120         mem->bus.addr = NULL;
 121 }
 122
 123 static int ttm_resource_ioremap(struct ttm_bo_device *bdev,
 124                                struct ttm_resource *mem,
 125                                void **virtual)
 126 {
 127         int ret;
 128         void *addr;
 129
 130         *virtual = NULL;
 131         ret = ttm_mem_io_reserve(bdev, mem);
 132         if (ret || !mem->bus.is_iomem)
 133                 return ret;
 134
 135         if (mem->bus.addr) {
 136                 addr = mem->bus.addr;
 137         } else {
 138                 size_t bus_size = (size_t)mem->num_pages << PAGE_SHIFT;
 139
 140                 if (mem->placement & TTM_PL_FLAG_WC)
 141                         addr = ioremap_wc(mem->bus.offset, bus_size);
 142                 else
 143                         addr = ioremap(mem->bus.offset, bus_size);
 144                 if (!addr) {
 145                         ttm_mem_io_free(bdev, mem);
 146                         return -ENOMEM;
 147                 }
 148         }
 149         *virtual = addr;
 150         return 0;
 151 }
 152
 153 static void ttm_resource_iounmap(struct ttm_bo_device *bdev,
 154                                 struct ttm_resource *mem,
 155                                 void *virtual)
 156 {
 157         if (virtual && mem->bus.addr == NULL)
 158                 iounmap(virtual);
 159         ttm_mem_io_free(bdev, mem);
 160 }
 161
 162 static int ttm_copy_io_page(void *dst, void *src, unsigned long page)
 163 {
 164         uint32_t *dstP =
 165             (uint32_t *) ((unsigned long)dst + (page << PAGE_SHIFT));
 166         uint32_t *srcP =
 167             (uint32_t *) ((unsigned long)src + (page << PAGE_SHIFT));
 168
 169         int i;
 170         for (i = 0; i < PAGE_SIZE / sizeof(uint32_t); ++i)
 171                 iowrite32(ioread32(srcP++), dstP++);
 172         return 0;
 173 }
 174
 175 static int ttm_copy_io_ttm_page(struct ttm_tt *ttm, void *src,
 176                                 unsigned long page,
 177                                 pgprot_t prot)
 178 {
 179         struct page *d = ttm->pages[page];
 180         void *dst;
 181
 182         if (!d)
 183                 return -ENOMEM;
 184
 185         src = (void *)((unsigned long)src + (page << PAGE_SHIFT));
 186         dst = kmap_atomic_prot(d, prot);
 187         if (!dst)
 188                 return -ENOMEM;
 189
 190         memcpy_fromio(dst, src, PAGE_SIZE);
 191
 192         kunmap_atomic(dst);
 193
 194         return 0;
 195 }
 196
 197 static int ttm_copy_ttm_io_page(struct ttm_tt *ttm, void *dst,
 198                                 unsigned long page,
 199                                 pgprot_t prot)
 200 {
 201         struct page *s = ttm->pages[page];
 202         void *src;
 203
 204         if (!s)
 205                 return -ENOMEM;
 206
 207         dst = (void *)((unsigned long)dst + (page << PAGE_SHIFT));
 208         src = kmap_atomic_prot(s, prot);
 209         if (!src)
 210                 return -ENOMEM;
 211
 212         memcpy_toio(dst, src, PAGE_SIZE);
 213
 214         kunmap_atomic(src);
 215
 216         return 0;
 217 }
 218
 219 int ttm_bo_move_memcpy(struct ttm_buffer_object *bo,
 220                        struct ttm_operation_ctx *ctx,
 221                        struct ttm_resource *new_mem)
 222 {
 223         struct ttm_bo_device *bdev = bo->bdev;
 224         struct ttm_resource_manager *man = ttm_manager_type(bdev, new_mem->mem_type);
 225         struct ttm_tt *ttm = bo->ttm;
 226         struct ttm_resource *old_mem = &bo->mem;
 227         struct ttm_resource old_copy = *old_mem;
 228         void *old_iomap;
 229         void *new_iomap;
 230         int ret;
 231         unsigned long i;
 232         unsigned long page;
 233         unsigned long add = 0;
 234         int dir;
 235
 236         ret = ttm_bo_wait(bo, ctx->interruptible, ctx->no_wait_gpu);
 237         if (ret)
 238                 return ret;
 239
 240         ret = ttm_resource_ioremap(bdev, old_mem, &old_iomap);
 241         if (ret)
 242                 return ret;
 243         ret = ttm_resource_ioremap(bdev, new_mem, &new_iomap);
 244         if (ret)
 245                 goto out;
 246
 247         /*
 248          * Single TTM move. NOP.
 249          */
 250         if (old_iomap == NULL && new_iomap == NULL)
 251                 goto out2;
 252
 253         /*
 254          * Don't move nonexistent data. Clear destination instead.
 255          */
 256         if (old_iomap == NULL &&
 257             (ttm == NULL || (!ttm_tt_is_populated(ttm) &&
 258                              !(ttm->page_flags & TTM_PAGE_FLAG_SWAPPED)))) {
 259                 memset_io(new_iomap, 0, new_mem->num_pages*PAGE_SIZE);
 260                 goto out2;
 261         }
 262
 263         /*
 264          * TTM might be null for moves within the same region.
 265          */
 266         if (ttm) {
 267                 ret = ttm_tt_populate(bdev, ttm, ctx);
 268                 if (ret)
 269                         goto out1;
 270         }
 271
 272         add = 0;
 273         dir = 1;
 274
 275         if ((old_mem->mem_type == new_mem->mem_type) &&
 276             (new_mem->start < old_mem->start + old_mem->size)) {
 277                 dir = -1;
 278                 add = new_mem->num_pages - 1;
 279         }
 280
 281         for (i = 0; i < new_mem->num_pages; ++i) {
 282                 page = i * dir + add;
 283                 if (old_iomap == NULL) {
 284                         pgprot_t prot = ttm_io_prot(old_mem->placement,
 285                                                     PAGE_KERNEL);
 286                         ret = ttm_copy_ttm_io_page(ttm, new_iomap, page,
 287                                                    prot);
 288                 } else if (new_iomap == NULL) {
 289                         pgprot_t prot = ttm_io_prot(new_mem->placement,
 290                                                     PAGE_KERNEL);
 291                         ret = ttm_copy_io_ttm_page(ttm, old_iomap, page,
 292                                                    prot);
 293                 } else {
 294                         ret = ttm_copy_io_page(new_iomap, old_iomap, page);
 295                 }
 296                 if (ret)
 297                         goto out1;
 298         }
 299         mb();
 300 out2:
 301         old_copy = *old_mem;
 302         *old_mem = *new_mem;
 303         new_mem->mm_node = NULL;
 304
 305         if (!man->use_tt)
 306                 ttm_bo_tt_destroy(bo);
 307
 308 out1:
 309         ttm_resource_iounmap(bdev, old_mem, new_iomap);
 310 out:
 311         ttm_resource_iounmap(bdev, &old_copy, old_iomap);
 312
 313         /*
 314          * On error, keep the mm node!
 315          */
 316         if (!ret)
 317                 ttm_resource_free(bo, &old_copy);
 318         return ret;
 319 }
 320 EXPORT_SYMBOL(ttm_bo_move_memcpy);
 321
 322 static void ttm_transfered_destroy(struct ttm_buffer_object *bo)
 323 {
 324         struct ttm_transfer_obj *fbo;
 325
 326         fbo = container_of(bo, struct ttm_transfer_obj, base);
 327         ttm_bo_put(fbo->bo);
 328         kfree(fbo);
 329 }
 330
 331 /**
 332  * ttm_buffer_object_transfer
 333  *
 334  * @bo: A pointer to a struct ttm_buffer_object.
 335  * @new_obj: A pointer to a pointer to a newly created ttm_buffer_object,
 336  * holding the data of @bo with the old placement.
 337  *
 338  * This is a utility function that may be called after an accelerated move
 339  * has been scheduled. A new buffer object is created as a placeholder for
 340  * the old data while it's being copied. When that buffer object is idle,
 341  * it can be destroyed, releasing the space of the old placement.
 342  * Returns:
 343  * !0: Failure.
 344  */
 345
 346 static int ttm_buffer_object_transfer(struct ttm_buffer_object *bo,
 347                                       struct ttm_buffer_object **new_obj)
 348 {
 349         struct ttm_transfer_obj *fbo;
 350         int ret;
 351
 352         fbo = kmalloc(sizeof(*fbo), GFP_KERNEL);
 353         if (!fbo)
 354                 return -ENOMEM;
 355
 356         fbo->base = *bo;
 357         fbo->base.mem.placement |= TTM_PL_FLAG_NO_EVICT;
 358
 359         ttm_bo_get(bo);
 360         fbo->bo = bo;
 361
 362         /**
 363          * Fix up members that we shouldn't copy directly:
 364          * TODO: Explicit member copy would probably be better here.
 365          */
 366
 367         atomic_inc(&ttm_bo_glob.bo_count);
 368         INIT_LIST_HEAD(&fbo->base.ddestroy);
 369         INIT_LIST_HEAD(&fbo->base.lru);
 370         INIT_LIST_HEAD(&fbo->base.swap);
 371         fbo->base.moving = NULL;
 372         drm_vma_node_reset(&fbo->base.base.vma_node);
 373
 374         kref_init(&fbo->base.kref);
 375         fbo->base.destroy = &ttm_transfered_destroy;
 376         fbo->base.acc_size = 0;
 377         if (bo->type != ttm_bo_type_sg)
 378                 fbo->base.base.resv = &fbo->base.base._resv;
 379
 380         dma_resv_init(&fbo->base.base._resv);
 381         fbo->base.base.dev = NULL;
 382         ret = dma_resv_trylock(&fbo->base.base._resv);
 383         WARN_ON(!ret);
 384
 385         *new_obj = &fbo->base;
 386         return 0;
 387 }
 388
 389 pgprot_t ttm_io_prot(uint32_t caching_flags, pgprot_t tmp)
 390 {
 391         /* Cached mappings need no adjustment */
 392         if (caching_flags & TTM_PL_FLAG_CACHED)
 393                 return tmp;
 394
 395 #if defined(__i386__) || defined(__x86_64__)
 396         if (caching_flags & TTM_PL_FLAG_WC)
 397                 tmp = pgprot_writecombine(tmp);
 398         else if (boot_cpu_data.x86 > 3)
 399                 tmp = pgprot_noncached(tmp);
 400 #endif
 401 #if defined(__ia64__) || defined(__arm__) || defined(__aarch64__) || \
 402     defined(__powerpc__) || defined(__mips__)
 403         if (caching_flags & TTM_PL_FLAG_WC)
 404                 tmp = pgprot_writecombine(tmp);
 405         else
 406                 tmp = pgprot_noncached(tmp);
 407 #endif
 408 #if defined(__sparc__)
 409         tmp = pgprot_noncached(tmp);
 410 #endif
 411         return tmp;
 412 }
 413 EXPORT_SYMBOL(ttm_io_prot);
 414
 415 static int ttm_bo_ioremap(struct ttm_buffer_object *bo,
 416                           unsigned long offset,
 417                           unsigned long size,
 418                           struct ttm_bo_kmap_obj *map)
 419 {
 420         struct ttm_resource *mem = &bo->mem;
 421
 422         if (bo->mem.bus.addr) {
 423                 map->bo_kmap_type = ttm_bo_map_premapped;
 424                 map->virtual = (void *)(((u8 *)bo->mem.bus.addr) + offset);
 425         } else {
 426                 map->bo_kmap_type = ttm_bo_map_iomap;
 427                 if (mem->placement & TTM_PL_FLAG_WC)
 428                         map->virtual = ioremap_wc(bo->mem.bus.offset + offset,
 429                                                   size);
 430                 else
 431                         map->virtual = ioremap(bo->mem.bus.offset + offset,
 432                                                size);
 433         }
 434         return (!map->virtual) ? -ENOMEM : 0;
 435 }
 436
 437 static int ttm_bo_kmap_ttm(struct ttm_buffer_object *bo,
 438                            unsigned long start_page,
 439                            unsigned long num_pages,
 440                            struct ttm_bo_kmap_obj *map)
 441 {
 442         struct ttm_resource *mem = &bo->mem;
 443         struct ttm_operation_ctx ctx = {
 444                 .interruptible = false,
 445                 .no_wait_gpu = false
 446         };
 447         struct ttm_tt *ttm = bo->ttm;
 448         pgprot_t prot;
 449         int ret;
 450
 451         BUG_ON(!ttm);
 452
 453         ret = ttm_tt_populate(bo->bdev, ttm, &ctx);
 454         if (ret)
 455                 return ret;
 456
 457         if (num_pages == 1 && (mem->placement & TTM_PL_FLAG_CACHED)) {
 458                 /*
 459                  * We're mapping a single page, and the desired
 460                  * page protection is consistent with the bo.
 461                  */
 462
 463                 map->bo_kmap_type = ttm_bo_map_kmap;
 464                 map->page = ttm->pages[start_page];
 465                 map->virtual = kmap(map->page);
 466         } else {
 467                 /*
 468                  * We need to use vmap to get the desired page protection
 469                  * or to make the buffer object look contiguous.
 470                  */
 471                 prot = ttm_io_prot(mem->placement, PAGE_KERNEL);
 472                 map->bo_kmap_type = ttm_bo_map_vmap;
 473                 map->virtual = vmap(ttm->pages + start_page, num_pages,
 474                                     0, prot);
 475         }
 476         return (!map->virtual) ? -ENOMEM : 0;
 477 }
 478
 479 int ttm_bo_kmap(struct ttm_buffer_object *bo,
 480                 unsigned long start_page, unsigned long num_pages,
 481                 struct ttm_bo_kmap_obj *map)
 482 {
 483         unsigned long offset, size;
 484         int ret;
 485
 486         map->virtual = NULL;
 487         map->bo = bo;
 488         if (num_pages > bo->num_pages)
 489                 return -EINVAL;
 490         if (start_page > bo->num_pages)
 491                 return -EINVAL;
 492
 493         ret = ttm_mem_io_reserve(bo->bdev, &bo->mem);
 494         if (ret)
 495                 return ret;
 496         if (!bo->mem.bus.is_iomem) {
 497                 return ttm_bo_kmap_ttm(bo, start_page, num_pages, map);
 498         } else {
 499                 offset = start_page << PAGE_SHIFT;
 500                 size = num_pages << PAGE_SHIFT;
 501                 return ttm_bo_ioremap(bo, offset, size, map);
 502         }
 503 }
 504 EXPORT_SYMBOL(ttm_bo_kmap);
 505
 506 void ttm_bo_kunmap(struct ttm_bo_kmap_obj *map)
 507 {
 508         if (!map->virtual)
 509                 return;
 510         switch (map->bo_kmap_type) {
 511         case ttm_bo_map_iomap:
 512                 iounmap(map->virtual);
 513                 break;
 514         case ttm_bo_map_vmap:
 515                 vunmap(map->virtual);
 516                 break;
 517         case ttm_bo_map_kmap:
 518                 kunmap(map->page);
 519                 break;
 520         case ttm_bo_map_premapped:
 521                 break;
 522         default:
 523                 BUG();
 524         }
 525         ttm_mem_io_free(map->bo->bdev, &map->bo->mem);
 526         map->virtual = NULL;
 527         map->page = NULL;
 528 }
 529 EXPORT_SYMBOL(ttm_bo_kunmap);
 530
 531 int ttm_bo_move_accel_cleanup(struct ttm_buffer_object *bo,
 532                               struct dma_fence *fence,
 533                               bool evict,
 534                               struct ttm_resource *new_mem)
 535 {
 536         struct ttm_bo_device *bdev = bo->bdev;
 537         struct ttm_resource_manager *man = ttm_manager_type(bdev, new_mem->mem_type);
 538         struct ttm_resource *old_mem = &bo->mem;
 539         int ret;
 540         struct ttm_buffer_object *ghost_obj;
 541
 542         dma_resv_add_excl_fence(bo->base.resv, fence);
 543         if (evict) {
 544                 ret = ttm_bo_wait(bo, false, false);
 545                 if (ret)
 546                         return ret;
 547
 548                 if (!man->use_tt)
 549                         ttm_bo_tt_destroy(bo);
 550                 ttm_bo_free_old_node(bo);
 551         } else {
 552                 /**
 553                  * This should help pipeline ordinary buffer moves.
 554                  *
 555                  * Hang old buffer memory on a new buffer object,
 556                  * and leave it to be released when the GPU
 557                  * operation has completed.
 558                  */
 559
 560                 dma_fence_put(bo->moving);
 561                 bo->moving = dma_fence_get(fence);
 562
 563                 ret = ttm_buffer_object_transfer(bo, &ghost_obj);
 564                 if (ret)
 565                         return ret;
 566
 567                 dma_resv_add_excl_fence(&ghost_obj->base._resv, fence);
 568
 569                 /**
 570                  * If we're not moving to fixed memory, the TTM object
 571                  * needs to stay alive. Otherwhise hang it on the ghost
 572                  * bo to be unbound and destroyed.
 573                  */
 574
 575                 if (man->use_tt)
 576                         ghost_obj->ttm = NULL;
 577                 else
 578                         bo->ttm = NULL;
 579
 580                 dma_resv_unlock(&ghost_obj->base._resv);
 581                 ttm_bo_put(ghost_obj);
 582         }
 583
 584         *old_mem = *new_mem;
 585         new_mem->mm_node = NULL;
 586
 587         return 0;
 588 }
 589 EXPORT_SYMBOL(ttm_bo_move_accel_cleanup);
 590
 591 int ttm_bo_pipeline_move(struct ttm_buffer_object *bo,
 592                          struct dma_fence *fence, bool evict,
 593                          struct ttm_resource *new_mem)
 594 {
 595         struct ttm_bo_device *bdev = bo->bdev;
 596         struct ttm_resource *old_mem = &bo->mem;
 597
 598         struct ttm_resource_manager *from = ttm_manager_type(bdev, old_mem->mem_type);
 599         struct ttm_resource_manager *to = ttm_manager_type(bdev, new_mem->mem_type);
 600
 601         int ret;
 602
 603         dma_resv_add_excl_fence(bo->base.resv, fence);
 604
 605         if (!evict) {
 606                 struct ttm_buffer_object *ghost_obj;
 607
 608                 /**
 609                  * This should help pipeline ordinary buffer moves.
 610                  *
 611                  * Hang old buffer memory on a new buffer object,
 612                  * and leave it to be released when the GPU
 613                  * operation has completed.
 614                  */
 615
 616                 dma_fence_put(bo->moving);
 617                 bo->moving = dma_fence_get(fence);
 618
 619                 ret = ttm_buffer_object_transfer(bo, &ghost_obj);
 620                 if (ret)
 621                         return ret;
 622
 623                 dma_resv_add_excl_fence(&ghost_obj->base._resv, fence);
 624
 625                 /**
 626                  * If we're not moving to fixed memory, the TTM object
 627                  * needs to stay alive. Otherwhise hang it on the ghost
 628                  * bo to be unbound and destroyed.
 629                  */
 630
 631                 if (to->use_tt)
 632                         ghost_obj->ttm = NULL;
 633                 else
 634                         bo->ttm = NULL;
 635
 636                 dma_resv_unlock(&ghost_obj->base._resv);
 637                 ttm_bo_put(ghost_obj);
 638
 639         } else if (!from->use_tt) {
 640
 641                 /**
 642                  * BO doesn't have a TTM we need to bind/unbind. Just remember
 643                  * this eviction and free up the allocation
 644                  */
 645
 646                 spin_lock(&from->move_lock);
 647                 if (!from->move || dma_fence_is_later(fence, from->move)) {
 648                         dma_fence_put(from->move);
 649                         from->move = dma_fence_get(fence);
 650                 }
 651                 spin_unlock(&from->move_lock);
 652
 653                 ttm_bo_free_old_node(bo);
 654
 655                 dma_fence_put(bo->moving);
 656                 bo->moving = dma_fence_get(fence);
 657
 658         } else {
 659                 /**
 660                  * Last resort, wait for the move to be completed.
 661                  *
 662                  * Should never happen in pratice.
 663                  */
 664
 665                 ret = ttm_bo_wait(bo, false, false);
 666                 if (ret)
 667                         return ret;
 668
 669                 if (!to->use_tt)
 670                         ttm_bo_tt_destroy(bo);
 671                 ttm_bo_free_old_node(bo);
 672         }
 673
 674         *old_mem = *new_mem;
 675         new_mem->mm_node = NULL;
 676
 677         return 0;
 678 }
 679 EXPORT_SYMBOL(ttm_bo_pipeline_move);
 680
 681 int ttm_bo_pipeline_gutting(struct ttm_buffer_object *bo)
 682 {
 683         struct ttm_buffer_object *ghost;
 684         int ret;
 685
 686         ret = ttm_buffer_object_transfer(bo, &ghost);
 687         if (ret)
 688                 return ret;
 689
 690         ret = dma_resv_copy_fences(&ghost->base._resv, bo->base.resv);
 691         /* Last resort, wait for the BO to be idle when we are OOM */
 692         if (ret)
 693                 ttm_bo_wait(bo, false, false);
 694
 695         memset(&bo->mem, 0, sizeof(bo->mem));
 696         bo->mem.mem_type = TTM_PL_SYSTEM;
 697         bo->ttm = NULL;
 698
 699         dma_resv_unlock(&ghost->base._resv);
 700         ttm_bo_put(ghost);
 701
 702         return 0;
 703 }