Add the rt linux 4.1.3-rt3 as base
[kvmfornfv.git] / kernel / drivers / gpu / drm / ttm / ttm_bo_util.c
1 /**************************************************************************
2  *
3  * Copyright (c) 2007-2009 VMware, Inc., Palo Alto, CA., USA
4  * All Rights Reserved.
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  * Authors: Thomas Hellstrom <thellstrom-at-vmware-dot-com>
29  */
30
31 #include <drm/ttm/ttm_bo_driver.h>
32 #include <drm/ttm/ttm_placement.h>
33 #include <drm/drm_vma_manager.h>
34 #include <linux/io.h>
35 #include <linux/highmem.h>
36 #include <linux/wait.h>
37 #include <linux/slab.h>
38 #include <linux/vmalloc.h>
39 #include <linux/module.h>
40 #include <linux/reservation.h>
41
42 void ttm_bo_free_old_node(struct ttm_buffer_object *bo)
43 {
44         ttm_bo_mem_put(bo, &bo->mem);
45 }
46
47 int ttm_bo_move_ttm(struct ttm_buffer_object *bo,
48                     bool evict,
49                     bool no_wait_gpu, struct ttm_mem_reg *new_mem)
50 {
51         struct ttm_tt *ttm = bo->ttm;
52         struct ttm_mem_reg *old_mem = &bo->mem;
53         int ret;
54
55         if (old_mem->mem_type != TTM_PL_SYSTEM) {
56                 ttm_tt_unbind(ttm);
57                 ttm_bo_free_old_node(bo);
58                 ttm_flag_masked(&old_mem->placement, TTM_PL_FLAG_SYSTEM,
59                                 TTM_PL_MASK_MEM);
60                 old_mem->mem_type = TTM_PL_SYSTEM;
61         }
62
63         ret = ttm_tt_set_placement_caching(ttm, new_mem->placement);
64         if (unlikely(ret != 0))
65                 return ret;
66
67         if (new_mem->mem_type != TTM_PL_SYSTEM) {
68                 ret = ttm_tt_bind(ttm, new_mem);
69                 if (unlikely(ret != 0))
70                         return ret;
71         }
72
73         *old_mem = *new_mem;
74         new_mem->mm_node = NULL;
75
76         return 0;
77 }
78 EXPORT_SYMBOL(ttm_bo_move_ttm);
79
80 int ttm_mem_io_lock(struct ttm_mem_type_manager *man, bool interruptible)
81 {
82         if (likely(man->io_reserve_fastpath))
83                 return 0;
84
85         if (interruptible)
86                 return mutex_lock_interruptible(&man->io_reserve_mutex);
87
88         mutex_lock(&man->io_reserve_mutex);
89         return 0;
90 }
91 EXPORT_SYMBOL(ttm_mem_io_lock);
92
93 void ttm_mem_io_unlock(struct ttm_mem_type_manager *man)
94 {
95         if (likely(man->io_reserve_fastpath))
96                 return;
97
98         mutex_unlock(&man->io_reserve_mutex);
99 }
100 EXPORT_SYMBOL(ttm_mem_io_unlock);
101
102 static int ttm_mem_io_evict(struct ttm_mem_type_manager *man)
103 {
104         struct ttm_buffer_object *bo;
105
106         if (!man->use_io_reserve_lru || list_empty(&man->io_reserve_lru))
107                 return -EAGAIN;
108
109         bo = list_first_entry(&man->io_reserve_lru,
110                               struct ttm_buffer_object,
111                               io_reserve_lru);
112         list_del_init(&bo->io_reserve_lru);
113         ttm_bo_unmap_virtual_locked(bo);
114
115         return 0;
116 }
117
118
119 int ttm_mem_io_reserve(struct ttm_bo_device *bdev,
120                        struct ttm_mem_reg *mem)
121 {
122         struct ttm_mem_type_manager *man = &bdev->man[mem->mem_type];
123         int ret = 0;
124
125         if (!bdev->driver->io_mem_reserve)
126                 return 0;
127         if (likely(man->io_reserve_fastpath))
128                 return bdev->driver->io_mem_reserve(bdev, mem);
129
130         if (bdev->driver->io_mem_reserve &&
131             mem->bus.io_reserved_count++ == 0) {
132 retry:
133                 ret = bdev->driver->io_mem_reserve(bdev, mem);
134                 if (ret == -EAGAIN) {
135                         ret = ttm_mem_io_evict(man);
136                         if (ret == 0)
137                                 goto retry;
138                 }
139         }
140         return ret;
141 }
142 EXPORT_SYMBOL(ttm_mem_io_reserve);
143
144 void ttm_mem_io_free(struct ttm_bo_device *bdev,
145                      struct ttm_mem_reg *mem)
146 {
147         struct ttm_mem_type_manager *man = &bdev->man[mem->mem_type];
148
149         if (likely(man->io_reserve_fastpath))
150                 return;
151
152         if (bdev->driver->io_mem_reserve &&
153             --mem->bus.io_reserved_count == 0 &&
154             bdev->driver->io_mem_free)
155                 bdev->driver->io_mem_free(bdev, mem);
156
157 }
158 EXPORT_SYMBOL(ttm_mem_io_free);
159
160 int ttm_mem_io_reserve_vm(struct ttm_buffer_object *bo)
161 {
162         struct ttm_mem_reg *mem = &bo->mem;
163         int ret;
164
165         if (!mem->bus.io_reserved_vm) {
166                 struct ttm_mem_type_manager *man =
167                         &bo->bdev->man[mem->mem_type];
168
169                 ret = ttm_mem_io_reserve(bo->bdev, mem);
170                 if (unlikely(ret != 0))
171                         return ret;
172                 mem->bus.io_reserved_vm = true;
173                 if (man->use_io_reserve_lru)
174                         list_add_tail(&bo->io_reserve_lru,
175                                       &man->io_reserve_lru);
176         }
177         return 0;
178 }
179
180 void ttm_mem_io_free_vm(struct ttm_buffer_object *bo)
181 {
182         struct ttm_mem_reg *mem = &bo->mem;
183
184         if (mem->bus.io_reserved_vm) {
185                 mem->bus.io_reserved_vm = false;
186                 list_del_init(&bo->io_reserve_lru);
187                 ttm_mem_io_free(bo->bdev, mem);
188         }
189 }
190
191 static int ttm_mem_reg_ioremap(struct ttm_bo_device *bdev, struct ttm_mem_reg *mem,
192                         void **virtual)
193 {
194         struct ttm_mem_type_manager *man = &bdev->man[mem->mem_type];
195         int ret;
196         void *addr;
197
198         *virtual = NULL;
199         (void) ttm_mem_io_lock(man, false);
200         ret = ttm_mem_io_reserve(bdev, mem);
201         ttm_mem_io_unlock(man);
202         if (ret || !mem->bus.is_iomem)
203                 return ret;
204
205         if (mem->bus.addr) {
206                 addr = mem->bus.addr;
207         } else {
208                 if (mem->placement & TTM_PL_FLAG_WC)
209                         addr = ioremap_wc(mem->bus.base + mem->bus.offset, mem->bus.size);
210                 else
211                         addr = ioremap_nocache(mem->bus.base + mem->bus.offset, mem->bus.size);
212                 if (!addr) {
213                         (void) ttm_mem_io_lock(man, false);
214                         ttm_mem_io_free(bdev, mem);
215                         ttm_mem_io_unlock(man);
216                         return -ENOMEM;
217                 }
218         }
219         *virtual = addr;
220         return 0;
221 }
222
223 static void ttm_mem_reg_iounmap(struct ttm_bo_device *bdev, struct ttm_mem_reg *mem,
224                          void *virtual)
225 {
226         struct ttm_mem_type_manager *man;
227
228         man = &bdev->man[mem->mem_type];
229
230         if (virtual && mem->bus.addr == NULL)
231                 iounmap(virtual);
232         (void) ttm_mem_io_lock(man, false);
233         ttm_mem_io_free(bdev, mem);
234         ttm_mem_io_unlock(man);
235 }
236
237 static int ttm_copy_io_page(void *dst, void *src, unsigned long page)
238 {
239         uint32_t *dstP =
240             (uint32_t *) ((unsigned long)dst + (page << PAGE_SHIFT));
241         uint32_t *srcP =
242             (uint32_t *) ((unsigned long)src + (page << PAGE_SHIFT));
243
244         int i;
245         for (i = 0; i < PAGE_SIZE / sizeof(uint32_t); ++i)
246                 iowrite32(ioread32(srcP++), dstP++);
247         return 0;
248 }
249
250 static int ttm_copy_io_ttm_page(struct ttm_tt *ttm, void *src,
251                                 unsigned long page,
252                                 pgprot_t prot)
253 {
254         struct page *d = ttm->pages[page];
255         void *dst;
256
257         if (!d)
258                 return -ENOMEM;
259
260         src = (void *)((unsigned long)src + (page << PAGE_SHIFT));
261
262 #ifdef CONFIG_X86
263         dst = kmap_atomic_prot(d, prot);
264 #else
265         if (pgprot_val(prot) != pgprot_val(PAGE_KERNEL))
266                 dst = vmap(&d, 1, 0, prot);
267         else
268                 dst = kmap(d);
269 #endif
270         if (!dst)
271                 return -ENOMEM;
272
273         memcpy_fromio(dst, src, PAGE_SIZE);
274
275 #ifdef CONFIG_X86
276         kunmap_atomic(dst);
277 #else
278         if (pgprot_val(prot) != pgprot_val(PAGE_KERNEL))
279                 vunmap(dst);
280         else
281                 kunmap(d);
282 #endif
283
284         return 0;
285 }
286
287 static int ttm_copy_ttm_io_page(struct ttm_tt *ttm, void *dst,
288                                 unsigned long page,
289                                 pgprot_t prot)
290 {
291         struct page *s = ttm->pages[page];
292         void *src;
293
294         if (!s)
295                 return -ENOMEM;
296
297         dst = (void *)((unsigned long)dst + (page << PAGE_SHIFT));
298 #ifdef CONFIG_X86
299         src = kmap_atomic_prot(s, prot);
300 #else
301         if (pgprot_val(prot) != pgprot_val(PAGE_KERNEL))
302                 src = vmap(&s, 1, 0, prot);
303         else
304                 src = kmap(s);
305 #endif
306         if (!src)
307                 return -ENOMEM;
308
309         memcpy_toio(dst, src, PAGE_SIZE);
310
311 #ifdef CONFIG_X86
312         kunmap_atomic(src);
313 #else
314         if (pgprot_val(prot) != pgprot_val(PAGE_KERNEL))
315                 vunmap(src);
316         else
317                 kunmap(s);
318 #endif
319
320         return 0;
321 }
322
323 int ttm_bo_move_memcpy(struct ttm_buffer_object *bo,
324                        bool evict, bool no_wait_gpu,
325                        struct ttm_mem_reg *new_mem)
326 {
327         struct ttm_bo_device *bdev = bo->bdev;
328         struct ttm_mem_type_manager *man = &bdev->man[new_mem->mem_type];
329         struct ttm_tt *ttm = bo->ttm;
330         struct ttm_mem_reg *old_mem = &bo->mem;
331         struct ttm_mem_reg old_copy = *old_mem;
332         void *old_iomap;
333         void *new_iomap;
334         int ret;
335         unsigned long i;
336         unsigned long page;
337         unsigned long add = 0;
338         int dir;
339
340         ret = ttm_mem_reg_ioremap(bdev, old_mem, &old_iomap);
341         if (ret)
342                 return ret;
343         ret = ttm_mem_reg_ioremap(bdev, new_mem, &new_iomap);
344         if (ret)
345                 goto out;
346
347         /*
348          * Single TTM move. NOP.
349          */
350         if (old_iomap == NULL && new_iomap == NULL)
351                 goto out2;
352
353         /*
354          * Don't move nonexistent data. Clear destination instead.
355          */
356         if (old_iomap == NULL &&
357             (ttm == NULL || (ttm->state == tt_unpopulated &&
358                              !(ttm->page_flags & TTM_PAGE_FLAG_SWAPPED)))) {
359                 memset_io(new_iomap, 0, new_mem->num_pages*PAGE_SIZE);
360                 goto out2;
361         }
362
363         /*
364          * TTM might be null for moves within the same region.
365          */
366         if (ttm && ttm->state == tt_unpopulated) {
367                 ret = ttm->bdev->driver->ttm_tt_populate(ttm);
368                 if (ret)
369                         goto out1;
370         }
371
372         add = 0;
373         dir = 1;
374
375         if ((old_mem->mem_type == new_mem->mem_type) &&
376             (new_mem->start < old_mem->start + old_mem->size)) {
377                 dir = -1;
378                 add = new_mem->num_pages - 1;
379         }
380
381         for (i = 0; i < new_mem->num_pages; ++i) {
382                 page = i * dir + add;
383                 if (old_iomap == NULL) {
384                         pgprot_t prot = ttm_io_prot(old_mem->placement,
385                                                     PAGE_KERNEL);
386                         ret = ttm_copy_ttm_io_page(ttm, new_iomap, page,
387                                                    prot);
388                 } else if (new_iomap == NULL) {
389                         pgprot_t prot = ttm_io_prot(new_mem->placement,
390                                                     PAGE_KERNEL);
391                         ret = ttm_copy_io_ttm_page(ttm, old_iomap, page,
392                                                    prot);
393                 } else
394                         ret = ttm_copy_io_page(new_iomap, old_iomap, page);
395                 if (ret)
396                         goto out1;
397         }
398         mb();
399 out2:
400         old_copy = *old_mem;
401         *old_mem = *new_mem;
402         new_mem->mm_node = NULL;
403
404         if ((man->flags & TTM_MEMTYPE_FLAG_FIXED) && (ttm != NULL)) {
405                 ttm_tt_unbind(ttm);
406                 ttm_tt_destroy(ttm);
407                 bo->ttm = NULL;
408         }
409
410 out1:
411         ttm_mem_reg_iounmap(bdev, old_mem, new_iomap);
412 out:
413         ttm_mem_reg_iounmap(bdev, &old_copy, old_iomap);
414
415         /*
416          * On error, keep the mm node!
417          */
418         if (!ret)
419                 ttm_bo_mem_put(bo, &old_copy);
420         return ret;
421 }
422 EXPORT_SYMBOL(ttm_bo_move_memcpy);
423
424 static void ttm_transfered_destroy(struct ttm_buffer_object *bo)
425 {
426         kfree(bo);
427 }
428
429 /**
430  * ttm_buffer_object_transfer
431  *
432  * @bo: A pointer to a struct ttm_buffer_object.
433  * @new_obj: A pointer to a pointer to a newly created ttm_buffer_object,
434  * holding the data of @bo with the old placement.
435  *
436  * This is a utility function that may be called after an accelerated move
437  * has been scheduled. A new buffer object is created as a placeholder for
438  * the old data while it's being copied. When that buffer object is idle,
439  * it can be destroyed, releasing the space of the old placement.
440  * Returns:
441  * !0: Failure.
442  */
443
444 static int ttm_buffer_object_transfer(struct ttm_buffer_object *bo,
445                                       struct ttm_buffer_object **new_obj)
446 {
447         struct ttm_buffer_object *fbo;
448         int ret;
449
450         fbo = kmalloc(sizeof(*fbo), GFP_KERNEL);
451         if (!fbo)
452                 return -ENOMEM;
453
454         *fbo = *bo;
455
456         /**
457          * Fix up members that we shouldn't copy directly:
458          * TODO: Explicit member copy would probably be better here.
459          */
460
461         INIT_LIST_HEAD(&fbo->ddestroy);
462         INIT_LIST_HEAD(&fbo->lru);
463         INIT_LIST_HEAD(&fbo->swap);
464         INIT_LIST_HEAD(&fbo->io_reserve_lru);
465         drm_vma_node_reset(&fbo->vma_node);
466         atomic_set(&fbo->cpu_writers, 0);
467
468         kref_init(&fbo->list_kref);
469         kref_init(&fbo->kref);
470         fbo->destroy = &ttm_transfered_destroy;
471         fbo->acc_size = 0;
472         fbo->resv = &fbo->ttm_resv;
473         reservation_object_init(fbo->resv);
474         ret = ww_mutex_trylock(&fbo->resv->lock);
475         WARN_ON(!ret);
476
477         *new_obj = fbo;
478         return 0;
479 }
480
481 pgprot_t ttm_io_prot(uint32_t caching_flags, pgprot_t tmp)
482 {
483         /* Cached mappings need no adjustment */
484         if (caching_flags & TTM_PL_FLAG_CACHED)
485                 return tmp;
486
487 #if defined(__i386__) || defined(__x86_64__)
488         if (caching_flags & TTM_PL_FLAG_WC)
489                 tmp = pgprot_writecombine(tmp);
490         else if (boot_cpu_data.x86 > 3)
491                 tmp = pgprot_noncached(tmp);
492 #endif
493 #if defined(__ia64__) || defined(__arm__) || defined(__powerpc__)
494         if (caching_flags & TTM_PL_FLAG_WC)
495                 tmp = pgprot_writecombine(tmp);
496         else
497                 tmp = pgprot_noncached(tmp);
498 #endif
499 #if defined(__sparc__) || defined(__mips__)
500         tmp = pgprot_noncached(tmp);
501 #endif
502         return tmp;
503 }
504 EXPORT_SYMBOL(ttm_io_prot);
505
506 static int ttm_bo_ioremap(struct ttm_buffer_object *bo,
507                           unsigned long offset,
508                           unsigned long size,
509                           struct ttm_bo_kmap_obj *map)
510 {
511         struct ttm_mem_reg *mem = &bo->mem;
512
513         if (bo->mem.bus.addr) {
514                 map->bo_kmap_type = ttm_bo_map_premapped;
515                 map->virtual = (void *)(((u8 *)bo->mem.bus.addr) + offset);
516         } else {
517                 map->bo_kmap_type = ttm_bo_map_iomap;
518                 if (mem->placement & TTM_PL_FLAG_WC)
519                         map->virtual = ioremap_wc(bo->mem.bus.base + bo->mem.bus.offset + offset,
520                                                   size);
521                 else
522                         map->virtual = ioremap_nocache(bo->mem.bus.base + bo->mem.bus.offset + offset,
523                                                        size);
524         }
525         return (!map->virtual) ? -ENOMEM : 0;
526 }
527
528 static int ttm_bo_kmap_ttm(struct ttm_buffer_object *bo,
529                            unsigned long start_page,
530                            unsigned long num_pages,
531                            struct ttm_bo_kmap_obj *map)
532 {
533         struct ttm_mem_reg *mem = &bo->mem; pgprot_t prot;
534         struct ttm_tt *ttm = bo->ttm;
535         int ret;
536
537         BUG_ON(!ttm);
538
539         if (ttm->state == tt_unpopulated) {
540                 ret = ttm->bdev->driver->ttm_tt_populate(ttm);
541                 if (ret)
542                         return ret;
543         }
544
545         if (num_pages == 1 && (mem->placement & TTM_PL_FLAG_CACHED)) {
546                 /*
547                  * We're mapping a single page, and the desired
548                  * page protection is consistent with the bo.
549                  */
550
551                 map->bo_kmap_type = ttm_bo_map_kmap;
552                 map->page = ttm->pages[start_page];
553                 map->virtual = kmap(map->page);
554         } else {
555                 /*
556                  * We need to use vmap to get the desired page protection
557                  * or to make the buffer object look contiguous.
558                  */
559                 prot = ttm_io_prot(mem->placement, PAGE_KERNEL);
560                 map->bo_kmap_type = ttm_bo_map_vmap;
561                 map->virtual = vmap(ttm->pages + start_page, num_pages,
562                                     0, prot);
563         }
564         return (!map->virtual) ? -ENOMEM : 0;
565 }
566
567 int ttm_bo_kmap(struct ttm_buffer_object *bo,
568                 unsigned long start_page, unsigned long num_pages,
569                 struct ttm_bo_kmap_obj *map)
570 {
571         struct ttm_mem_type_manager *man =
572                 &bo->bdev->man[bo->mem.mem_type];
573         unsigned long offset, size;
574         int ret;
575
576         BUG_ON(!list_empty(&bo->swap));
577         map->virtual = NULL;
578         map->bo = bo;
579         if (num_pages > bo->num_pages)
580                 return -EINVAL;
581         if (start_page > bo->num_pages)
582                 return -EINVAL;
583 #if 0
584         if (num_pages > 1 && !capable(CAP_SYS_ADMIN))
585                 return -EPERM;
586 #endif
587         (void) ttm_mem_io_lock(man, false);
588         ret = ttm_mem_io_reserve(bo->bdev, &bo->mem);
589         ttm_mem_io_unlock(man);
590         if (ret)
591                 return ret;
592         if (!bo->mem.bus.is_iomem) {
593                 return ttm_bo_kmap_ttm(bo, start_page, num_pages, map);
594         } else {
595                 offset = start_page << PAGE_SHIFT;
596                 size = num_pages << PAGE_SHIFT;
597                 return ttm_bo_ioremap(bo, offset, size, map);
598         }
599 }
600 EXPORT_SYMBOL(ttm_bo_kmap);
601
602 void ttm_bo_kunmap(struct ttm_bo_kmap_obj *map)
603 {
604         struct ttm_buffer_object *bo = map->bo;
605         struct ttm_mem_type_manager *man =
606                 &bo->bdev->man[bo->mem.mem_type];
607
608         if (!map->virtual)
609                 return;
610         switch (map->bo_kmap_type) {
611         case ttm_bo_map_iomap:
612                 iounmap(map->virtual);
613                 break;
614         case ttm_bo_map_vmap:
615                 vunmap(map->virtual);
616                 break;
617         case ttm_bo_map_kmap:
618                 kunmap(map->page);
619                 break;
620         case ttm_bo_map_premapped:
621                 break;
622         default:
623                 BUG();
624         }
625         (void) ttm_mem_io_lock(man, false);
626         ttm_mem_io_free(map->bo->bdev, &map->bo->mem);
627         ttm_mem_io_unlock(man);
628         map->virtual = NULL;
629         map->page = NULL;
630 }
631 EXPORT_SYMBOL(ttm_bo_kunmap);
632
633 int ttm_bo_move_accel_cleanup(struct ttm_buffer_object *bo,
634                               struct fence *fence,
635                               bool evict,
636                               bool no_wait_gpu,
637                               struct ttm_mem_reg *new_mem)
638 {
639         struct ttm_bo_device *bdev = bo->bdev;
640         struct ttm_mem_type_manager *man = &bdev->man[new_mem->mem_type];
641         struct ttm_mem_reg *old_mem = &bo->mem;
642         int ret;
643         struct ttm_buffer_object *ghost_obj;
644
645         reservation_object_add_excl_fence(bo->resv, fence);
646         if (evict) {
647                 ret = ttm_bo_wait(bo, false, false, false);
648                 if (ret)
649                         return ret;
650
651                 if ((man->flags & TTM_MEMTYPE_FLAG_FIXED) &&
652                     (bo->ttm != NULL)) {
653                         ttm_tt_unbind(bo->ttm);
654                         ttm_tt_destroy(bo->ttm);
655                         bo->ttm = NULL;
656                 }
657                 ttm_bo_free_old_node(bo);
658         } else {
659                 /**
660                  * This should help pipeline ordinary buffer moves.
661                  *
662                  * Hang old buffer memory on a new buffer object,
663                  * and leave it to be released when the GPU
664                  * operation has completed.
665                  */
666
667                 set_bit(TTM_BO_PRIV_FLAG_MOVING, &bo->priv_flags);
668
669                 ret = ttm_buffer_object_transfer(bo, &ghost_obj);
670                 if (ret)
671                         return ret;
672
673                 reservation_object_add_excl_fence(ghost_obj->resv, fence);
674
675                 /**
676                  * If we're not moving to fixed memory, the TTM object
677                  * needs to stay alive. Otherwhise hang it on the ghost
678                  * bo to be unbound and destroyed.
679                  */
680
681                 if (!(man->flags & TTM_MEMTYPE_FLAG_FIXED))
682                         ghost_obj->ttm = NULL;
683                 else
684                         bo->ttm = NULL;
685
686                 ttm_bo_unreserve(ghost_obj);
687                 ttm_bo_unref(&ghost_obj);
688         }
689
690         *old_mem = *new_mem;
691         new_mem->mm_node = NULL;
692
693         return 0;
694 }
695 EXPORT_SYMBOL(ttm_bo_move_accel_cleanup);