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_cache.h>
35 #include <drm/drm_vma_manager.h>
36 #include <linux/dma-buf-map.h>
37 #include <linux/io.h>
38 #include <linux/highmem.h>
39 #include <linux/wait.h>
40 #include <linux/slab.h>
41 #include <linux/vmalloc.h>
42 #include <linux/module.h>
43 #include <linux/dma-resv.h>
44
45 struct ttm_transfer_obj {
46 struct ttm_buffer_object base;
47 struct ttm_buffer_object *bo;
48 };
49
ttm_mem_io_reserve(struct ttm_device * bdev,struct ttm_resource * mem)50 int ttm_mem_io_reserve(struct ttm_device *bdev,
51 struct ttm_resource *mem)
52 {
53 if (mem->bus.offset || mem->bus.addr)
54 return 0;
55
56 mem->bus.is_iomem = false;
57 if (!bdev->funcs->io_mem_reserve)
58 return 0;
59
60 return bdev->funcs->io_mem_reserve(bdev, mem);
61 }
62
ttm_mem_io_free(struct ttm_device * bdev,struct ttm_resource * mem)63 void ttm_mem_io_free(struct ttm_device *bdev,
64 struct ttm_resource *mem)
65 {
66 if (!mem)
67 return;
68
69 if (!mem->bus.offset && !mem->bus.addr)
70 return;
71
72 if (bdev->funcs->io_mem_free)
73 bdev->funcs->io_mem_free(bdev, mem);
74
75 mem->bus.offset = 0;
76 mem->bus.addr = NULL;
77 }
78
79 /**
80 * ttm_move_memcpy - Helper to perform a memcpy ttm move operation.
81 * @bo: The struct ttm_buffer_object.
82 * @new_mem: The struct ttm_resource we're moving to (copy destination).
83 * @new_iter: A struct ttm_kmap_iter representing the destination resource.
84 * @src_iter: A struct ttm_kmap_iter representing the source resource.
85 *
86 * This function is intended to be able to move out async under a
87 * dma-fence if desired.
88 */
ttm_move_memcpy(struct ttm_buffer_object * bo,u32 num_pages,struct ttm_kmap_iter * dst_iter,struct ttm_kmap_iter * src_iter)89 void ttm_move_memcpy(struct ttm_buffer_object *bo,
90 u32 num_pages,
91 struct ttm_kmap_iter *dst_iter,
92 struct ttm_kmap_iter *src_iter)
93 {
94 const struct ttm_kmap_iter_ops *dst_ops = dst_iter->ops;
95 const struct ttm_kmap_iter_ops *src_ops = src_iter->ops;
96 struct ttm_tt *ttm = bo->ttm;
97 struct dma_buf_map src_map, dst_map;
98 pgoff_t i;
99
100 /* Single TTM move. NOP */
101 if (dst_ops->maps_tt && src_ops->maps_tt)
102 return;
103
104 /* Don't move nonexistent data. Clear destination instead. */
105 if (src_ops->maps_tt && (!ttm || !ttm_tt_is_populated(ttm))) {
106 if (ttm && !(ttm->page_flags & TTM_PAGE_FLAG_ZERO_ALLOC))
107 return;
108
109 for (i = 0; i < num_pages; ++i) {
110 dst_ops->map_local(dst_iter, &dst_map, i);
111 if (dst_map.is_iomem)
112 memset_io(dst_map.vaddr_iomem, 0, PAGE_SIZE);
113 else
114 memset(dst_map.vaddr, 0, PAGE_SIZE);
115 if (dst_ops->unmap_local)
116 dst_ops->unmap_local(dst_iter, &dst_map);
117 }
118 return;
119 }
120
121 for (i = 0; i < num_pages; ++i) {
122 dst_ops->map_local(dst_iter, &dst_map, i);
123 src_ops->map_local(src_iter, &src_map, i);
124
125 drm_memcpy_from_wc(&dst_map, &src_map, PAGE_SIZE);
126
127 if (src_ops->unmap_local)
128 src_ops->unmap_local(src_iter, &src_map);
129 if (dst_ops->unmap_local)
130 dst_ops->unmap_local(dst_iter, &dst_map);
131 }
132 }
133 EXPORT_SYMBOL(ttm_move_memcpy);
134
ttm_bo_move_memcpy(struct ttm_buffer_object * bo,struct ttm_operation_ctx * ctx,struct ttm_resource * dst_mem)135 int ttm_bo_move_memcpy(struct ttm_buffer_object *bo,
136 struct ttm_operation_ctx *ctx,
137 struct ttm_resource *dst_mem)
138 {
139 struct ttm_device *bdev = bo->bdev;
140 struct ttm_resource_manager *dst_man =
141 ttm_manager_type(bo->bdev, dst_mem->mem_type);
142 struct ttm_tt *ttm = bo->ttm;
143 struct ttm_resource *src_mem = bo->resource;
144 struct ttm_resource_manager *src_man =
145 ttm_manager_type(bdev, src_mem->mem_type);
146 union {
147 struct ttm_kmap_iter_tt tt;
148 struct ttm_kmap_iter_linear_io io;
149 } _dst_iter, _src_iter;
150 struct ttm_kmap_iter *dst_iter, *src_iter;
151 int ret = 0;
152
153 if (ttm && ((ttm->page_flags & TTM_PAGE_FLAG_SWAPPED) ||
154 dst_man->use_tt)) {
155 ret = ttm_tt_populate(bdev, ttm, ctx);
156 if (ret)
157 return ret;
158 }
159
160 dst_iter = ttm_kmap_iter_linear_io_init(&_dst_iter.io, bdev, dst_mem);
161 if (PTR_ERR(dst_iter) == -EINVAL && dst_man->use_tt)
162 dst_iter = ttm_kmap_iter_tt_init(&_dst_iter.tt, bo->ttm);
163 if (IS_ERR(dst_iter))
164 return PTR_ERR(dst_iter);
165
166 src_iter = ttm_kmap_iter_linear_io_init(&_src_iter.io, bdev, src_mem);
167 if (PTR_ERR(src_iter) == -EINVAL && src_man->use_tt)
168 src_iter = ttm_kmap_iter_tt_init(&_src_iter.tt, bo->ttm);
169 if (IS_ERR(src_iter)) {
170 ret = PTR_ERR(src_iter);
171 goto out_src_iter;
172 }
173
174 ttm_move_memcpy(bo, dst_mem->num_pages, dst_iter, src_iter);
175
176 if (!src_iter->ops->maps_tt)
177 ttm_kmap_iter_linear_io_fini(&_src_iter.io, bdev, src_mem);
178 ttm_bo_move_sync_cleanup(bo, dst_mem);
179
180 out_src_iter:
181 if (!dst_iter->ops->maps_tt)
182 ttm_kmap_iter_linear_io_fini(&_dst_iter.io, bdev, dst_mem);
183
184 return ret;
185 }
186 EXPORT_SYMBOL(ttm_bo_move_memcpy);
187
ttm_transfered_destroy(struct ttm_buffer_object * bo)188 static void ttm_transfered_destroy(struct ttm_buffer_object *bo)
189 {
190 struct ttm_transfer_obj *fbo;
191
192 fbo = container_of(bo, struct ttm_transfer_obj, base);
193 dma_resv_fini(&fbo->base.base._resv);
194 ttm_bo_put(fbo->bo);
195 kfree(fbo);
196 }
197
198 /**
199 * ttm_buffer_object_transfer
200 *
201 * @bo: A pointer to a struct ttm_buffer_object.
202 * @new_obj: A pointer to a pointer to a newly created ttm_buffer_object,
203 * holding the data of @bo with the old placement.
204 *
205 * This is a utility function that may be called after an accelerated move
206 * has been scheduled. A new buffer object is created as a placeholder for
207 * the old data while it's being copied. When that buffer object is idle,
208 * it can be destroyed, releasing the space of the old placement.
209 * Returns:
210 * !0: Failure.
211 */
212
ttm_buffer_object_transfer(struct ttm_buffer_object * bo,struct ttm_buffer_object ** new_obj)213 static int ttm_buffer_object_transfer(struct ttm_buffer_object *bo,
214 struct ttm_buffer_object **new_obj)
215 {
216 struct ttm_transfer_obj *fbo;
217 int ret;
218
219 fbo = kmalloc(sizeof(*fbo), GFP_KERNEL);
220 if (!fbo)
221 return -ENOMEM;
222
223 fbo->base = *bo;
224
225 ttm_bo_get(bo);
226 fbo->bo = bo;
227
228 /**
229 * Fix up members that we shouldn't copy directly:
230 * TODO: Explicit member copy would probably be better here.
231 */
232
233 atomic_inc(&ttm_glob.bo_count);
234 INIT_LIST_HEAD(&fbo->base.ddestroy);
235 INIT_LIST_HEAD(&fbo->base.lru);
236 fbo->base.moving = NULL;
237 drm_vma_node_reset(&fbo->base.base.vma_node);
238
239 kref_init(&fbo->base.kref);
240 fbo->base.destroy = &ttm_transfered_destroy;
241 fbo->base.pin_count = 0;
242 if (bo->type != ttm_bo_type_sg)
243 fbo->base.base.resv = &fbo->base.base._resv;
244
245 dma_resv_init(&fbo->base.base._resv);
246 fbo->base.base.dev = NULL;
247 ret = dma_resv_trylock(&fbo->base.base._resv);
248 WARN_ON(!ret);
249
250 ttm_bo_move_to_lru_tail_unlocked(&fbo->base);
251
252 *new_obj = &fbo->base;
253 return 0;
254 }
255
ttm_io_prot(struct ttm_buffer_object * bo,struct ttm_resource * res,pgprot_t tmp)256 pgprot_t ttm_io_prot(struct ttm_buffer_object *bo, struct ttm_resource *res,
257 pgprot_t tmp)
258 {
259 struct ttm_resource_manager *man;
260 enum ttm_caching caching;
261
262 man = ttm_manager_type(bo->bdev, res->mem_type);
263 caching = man->use_tt ? bo->ttm->caching : res->bus.caching;
264
265 return ttm_prot_from_caching(caching, tmp);
266 }
267 EXPORT_SYMBOL(ttm_io_prot);
268
ttm_bo_ioremap(struct ttm_buffer_object * bo,unsigned long offset,unsigned long size,struct ttm_bo_kmap_obj * map)269 static int ttm_bo_ioremap(struct ttm_buffer_object *bo,
270 unsigned long offset,
271 unsigned long size,
272 struct ttm_bo_kmap_obj *map)
273 {
274 struct ttm_resource *mem = bo->resource;
275
276 if (bo->resource->bus.addr) {
277 map->bo_kmap_type = ttm_bo_map_premapped;
278 map->virtual = ((u8 *)bo->resource->bus.addr) + offset;
279 } else {
280 resource_size_t res = bo->resource->bus.offset + offset;
281
282 map->bo_kmap_type = ttm_bo_map_iomap;
283 if (mem->bus.caching == ttm_write_combined)
284 map->virtual = ioremap_wc(res, size);
285 #ifdef CONFIG_X86
286 else if (mem->bus.caching == ttm_cached)
287 map->virtual = ioremap_cache(res, size);
288 #endif
289 else
290 map->virtual = ioremap(res, size);
291 }
292 return (!map->virtual) ? -ENOMEM : 0;
293 }
294
ttm_bo_kmap_ttm(struct ttm_buffer_object * bo,unsigned long start_page,unsigned long num_pages,struct ttm_bo_kmap_obj * map)295 static int ttm_bo_kmap_ttm(struct ttm_buffer_object *bo,
296 unsigned long start_page,
297 unsigned long num_pages,
298 struct ttm_bo_kmap_obj *map)
299 {
300 struct ttm_resource *mem = bo->resource;
301 struct ttm_operation_ctx ctx = {
302 .interruptible = false,
303 .no_wait_gpu = false
304 };
305 struct ttm_tt *ttm = bo->ttm;
306 pgprot_t prot;
307 int ret;
308
309 BUG_ON(!ttm);
310
311 ret = ttm_tt_populate(bo->bdev, ttm, &ctx);
312 if (ret)
313 return ret;
314
315 if (num_pages == 1 && ttm->caching == ttm_cached) {
316 /*
317 * We're mapping a single page, and the desired
318 * page protection is consistent with the bo.
319 */
320
321 map->bo_kmap_type = ttm_bo_map_kmap;
322 map->page = ttm->pages[start_page];
323 map->virtual = kmap(map->page);
324 } else {
325 /*
326 * We need to use vmap to get the desired page protection
327 * or to make the buffer object look contiguous.
328 */
329 prot = ttm_io_prot(bo, mem, PAGE_KERNEL);
330 map->bo_kmap_type = ttm_bo_map_vmap;
331 map->virtual = vmap(ttm->pages + start_page, num_pages,
332 0, prot);
333 }
334 return (!map->virtual) ? -ENOMEM : 0;
335 }
336
ttm_bo_kmap(struct ttm_buffer_object * bo,unsigned long start_page,unsigned long num_pages,struct ttm_bo_kmap_obj * map)337 int ttm_bo_kmap(struct ttm_buffer_object *bo,
338 unsigned long start_page, unsigned long num_pages,
339 struct ttm_bo_kmap_obj *map)
340 {
341 unsigned long offset, size;
342 int ret;
343
344 map->virtual = NULL;
345 map->bo = bo;
346 if (num_pages > bo->resource->num_pages)
347 return -EINVAL;
348 if ((start_page + num_pages) > bo->resource->num_pages)
349 return -EINVAL;
350
351 ret = ttm_mem_io_reserve(bo->bdev, bo->resource);
352 if (ret)
353 return ret;
354 if (!bo->resource->bus.is_iomem) {
355 return ttm_bo_kmap_ttm(bo, start_page, num_pages, map);
356 } else {
357 offset = start_page << PAGE_SHIFT;
358 size = num_pages << PAGE_SHIFT;
359 return ttm_bo_ioremap(bo, offset, size, map);
360 }
361 }
362 EXPORT_SYMBOL(ttm_bo_kmap);
363
ttm_bo_kunmap(struct ttm_bo_kmap_obj * map)364 void ttm_bo_kunmap(struct ttm_bo_kmap_obj *map)
365 {
366 if (!map->virtual)
367 return;
368 switch (map->bo_kmap_type) {
369 case ttm_bo_map_iomap:
370 iounmap(map->virtual);
371 break;
372 case ttm_bo_map_vmap:
373 vunmap(map->virtual);
374 break;
375 case ttm_bo_map_kmap:
376 kunmap(map->page);
377 break;
378 case ttm_bo_map_premapped:
379 break;
380 default:
381 BUG();
382 }
383 ttm_mem_io_free(map->bo->bdev, map->bo->resource);
384 map->virtual = NULL;
385 map->page = NULL;
386 }
387 EXPORT_SYMBOL(ttm_bo_kunmap);
388
ttm_bo_vmap(struct ttm_buffer_object * bo,struct dma_buf_map * map)389 int ttm_bo_vmap(struct ttm_buffer_object *bo, struct dma_buf_map *map)
390 {
391 struct ttm_resource *mem = bo->resource;
392 int ret;
393
394 ret = ttm_mem_io_reserve(bo->bdev, mem);
395 if (ret)
396 return ret;
397
398 if (mem->bus.is_iomem) {
399 void __iomem *vaddr_iomem;
400
401 if (mem->bus.addr)
402 vaddr_iomem = (void __iomem *)mem->bus.addr;
403 else if (mem->bus.caching == ttm_write_combined)
404 vaddr_iomem = ioremap_wc(mem->bus.offset,
405 bo->base.size);
406 #ifdef CONFIG_X86
407 else if (mem->bus.caching == ttm_cached)
408 vaddr_iomem = ioremap_cache(mem->bus.offset,
409 bo->base.size);
410 #endif
411 else
412 vaddr_iomem = ioremap(mem->bus.offset, bo->base.size);
413
414 if (!vaddr_iomem)
415 return -ENOMEM;
416
417 dma_buf_map_set_vaddr_iomem(map, vaddr_iomem);
418
419 } else {
420 struct ttm_operation_ctx ctx = {
421 .interruptible = false,
422 .no_wait_gpu = false
423 };
424 struct ttm_tt *ttm = bo->ttm;
425 pgprot_t prot;
426 void *vaddr;
427
428 ret = ttm_tt_populate(bo->bdev, ttm, &ctx);
429 if (ret)
430 return ret;
431
432 /*
433 * We need to use vmap to get the desired page protection
434 * or to make the buffer object look contiguous.
435 */
436 prot = ttm_io_prot(bo, mem, PAGE_KERNEL);
437 vaddr = vmap(ttm->pages, ttm->num_pages, 0, prot);
438 if (!vaddr)
439 return -ENOMEM;
440
441 dma_buf_map_set_vaddr(map, vaddr);
442 }
443
444 return 0;
445 }
446 EXPORT_SYMBOL(ttm_bo_vmap);
447
ttm_bo_vunmap(struct ttm_buffer_object * bo,struct dma_buf_map * map)448 void ttm_bo_vunmap(struct ttm_buffer_object *bo, struct dma_buf_map *map)
449 {
450 struct ttm_resource *mem = bo->resource;
451
452 if (dma_buf_map_is_null(map))
453 return;
454
455 if (!map->is_iomem)
456 vunmap(map->vaddr);
457 else if (!mem->bus.addr)
458 iounmap(map->vaddr_iomem);
459 dma_buf_map_clear(map);
460
461 ttm_mem_io_free(bo->bdev, bo->resource);
462 }
463 EXPORT_SYMBOL(ttm_bo_vunmap);
464
ttm_bo_wait_free_node(struct ttm_buffer_object * bo,bool dst_use_tt)465 static int ttm_bo_wait_free_node(struct ttm_buffer_object *bo,
466 bool dst_use_tt)
467 {
468 int ret;
469 ret = ttm_bo_wait(bo, false, false);
470 if (ret)
471 return ret;
472
473 if (!dst_use_tt)
474 ttm_bo_tt_destroy(bo);
475 ttm_resource_free(bo, &bo->resource);
476 return 0;
477 }
478
ttm_bo_move_to_ghost(struct ttm_buffer_object * bo,struct dma_fence * fence,bool dst_use_tt)479 static int ttm_bo_move_to_ghost(struct ttm_buffer_object *bo,
480 struct dma_fence *fence,
481 bool dst_use_tt)
482 {
483 struct ttm_buffer_object *ghost_obj;
484 int ret;
485
486 /**
487 * This should help pipeline ordinary buffer moves.
488 *
489 * Hang old buffer memory on a new buffer object,
490 * and leave it to be released when the GPU
491 * operation has completed.
492 */
493
494 dma_fence_put(bo->moving);
495 bo->moving = dma_fence_get(fence);
496
497 ret = ttm_buffer_object_transfer(bo, &ghost_obj);
498 if (ret)
499 return ret;
500
501 dma_resv_add_excl_fence(&ghost_obj->base._resv, fence);
502
503 /**
504 * If we're not moving to fixed memory, the TTM object
505 * needs to stay alive. Otherwhise hang it on the ghost
506 * bo to be unbound and destroyed.
507 */
508
509 if (dst_use_tt)
510 ghost_obj->ttm = NULL;
511 else
512 bo->ttm = NULL;
513 bo->resource = NULL;
514
515 dma_resv_unlock(&ghost_obj->base._resv);
516 ttm_bo_put(ghost_obj);
517 return 0;
518 }
519
ttm_bo_move_pipeline_evict(struct ttm_buffer_object * bo,struct dma_fence * fence)520 static void ttm_bo_move_pipeline_evict(struct ttm_buffer_object *bo,
521 struct dma_fence *fence)
522 {
523 struct ttm_device *bdev = bo->bdev;
524 struct ttm_resource_manager *from;
525
526 from = ttm_manager_type(bdev, bo->resource->mem_type);
527
528 /**
529 * BO doesn't have a TTM we need to bind/unbind. Just remember
530 * this eviction and free up the allocation
531 */
532 spin_lock(&from->move_lock);
533 if (!from->move || dma_fence_is_later(fence, from->move)) {
534 dma_fence_put(from->move);
535 from->move = dma_fence_get(fence);
536 }
537 spin_unlock(&from->move_lock);
538
539 ttm_resource_free(bo, &bo->resource);
540
541 dma_fence_put(bo->moving);
542 bo->moving = dma_fence_get(fence);
543 }
544
ttm_bo_move_accel_cleanup(struct ttm_buffer_object * bo,struct dma_fence * fence,bool evict,bool pipeline,struct ttm_resource * new_mem)545 int ttm_bo_move_accel_cleanup(struct ttm_buffer_object *bo,
546 struct dma_fence *fence,
547 bool evict,
548 bool pipeline,
549 struct ttm_resource *new_mem)
550 {
551 struct ttm_device *bdev = bo->bdev;
552 struct ttm_resource_manager *from = ttm_manager_type(bdev, bo->resource->mem_type);
553 struct ttm_resource_manager *man = ttm_manager_type(bdev, new_mem->mem_type);
554 int ret = 0;
555
556 dma_resv_add_excl_fence(bo->base.resv, fence);
557 if (!evict)
558 ret = ttm_bo_move_to_ghost(bo, fence, man->use_tt);
559 else if (!from->use_tt && pipeline)
560 ttm_bo_move_pipeline_evict(bo, fence);
561 else
562 ret = ttm_bo_wait_free_node(bo, man->use_tt);
563
564 if (ret)
565 return ret;
566
567 ttm_bo_assign_mem(bo, new_mem);
568
569 return 0;
570 }
571 EXPORT_SYMBOL(ttm_bo_move_accel_cleanup);
572
573 /**
574 * ttm_bo_pipeline_gutting - purge the contents of a bo
575 * @bo: The buffer object
576 *
577 * Purge the contents of a bo, async if the bo is not idle.
578 * After a successful call, the bo is left unpopulated in
579 * system placement. The function may wait uninterruptible
580 * for idle on OOM.
581 *
582 * Return: 0 if successful, negative error code on failure.
583 */
ttm_bo_pipeline_gutting(struct ttm_buffer_object * bo)584 int ttm_bo_pipeline_gutting(struct ttm_buffer_object *bo)
585 {
586 static const struct ttm_place sys_mem = { .mem_type = TTM_PL_SYSTEM };
587 struct ttm_buffer_object *ghost;
588 struct ttm_resource *sys_res;
589 struct ttm_tt *ttm;
590 int ret;
591
592 ret = ttm_resource_alloc(bo, &sys_mem, &sys_res);
593 if (ret)
594 return ret;
595
596 /* If already idle, no need for ghost object dance. */
597 ret = ttm_bo_wait(bo, false, true);
598 if (ret != -EBUSY) {
599 if (!bo->ttm) {
600 /* See comment below about clearing. */
601 ret = ttm_tt_create(bo, true);
602 if (ret)
603 goto error_free_sys_mem;
604 } else {
605 ttm_tt_unpopulate(bo->bdev, bo->ttm);
606 if (bo->type == ttm_bo_type_device)
607 ttm_tt_mark_for_clear(bo->ttm);
608 }
609 ttm_resource_free(bo, &bo->resource);
610 ttm_bo_assign_mem(bo, sys_res);
611 return 0;
612 }
613
614 /*
615 * We need an unpopulated ttm_tt after giving our current one,
616 * if any, to the ghost object. And we can't afford to fail
617 * creating one *after* the operation. If the bo subsequently gets
618 * resurrected, make sure it's cleared (if ttm_bo_type_device)
619 * to avoid leaking sensitive information to user-space.
620 */
621
622 ttm = bo->ttm;
623 bo->ttm = NULL;
624 ret = ttm_tt_create(bo, true);
625 swap(bo->ttm, ttm);
626 if (ret)
627 goto error_free_sys_mem;
628
629 ret = ttm_buffer_object_transfer(bo, &ghost);
630 if (ret)
631 goto error_destroy_tt;
632
633 ret = dma_resv_copy_fences(&ghost->base._resv, bo->base.resv);
634 /* Last resort, wait for the BO to be idle when we are OOM */
635 if (ret)
636 ttm_bo_wait(bo, false, false);
637
638 dma_resv_unlock(&ghost->base._resv);
639 ttm_bo_put(ghost);
640 bo->ttm = ttm;
641 bo->resource = NULL;
642 ttm_bo_assign_mem(bo, sys_res);
643 return 0;
644
645 error_destroy_tt:
646 ttm_tt_destroy(bo->bdev, ttm);
647
648 error_free_sys_mem:
649 ttm_resource_free(bo, &sys_res);
650 return ret;
651 }
652