xref: /freebsd/sys/dev/drm2/ttm/ttm_bo_util.c (revision d0b2dbfa0ecf2bbc9709efc5e20baf8e4b44bbbf)
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 <sys/cdefs.h>
32 #include <dev/drm2/drmP.h>
33 #include <dev/drm2/ttm/ttm_bo_driver.h>
34 #include <dev/drm2/ttm/ttm_placement.h>
35 #include <sys/sf_buf.h>
36 
37 void ttm_bo_free_old_node(struct ttm_buffer_object *bo)
38 {
39 	ttm_bo_mem_put(bo, &bo->mem);
40 }
41 
42 int ttm_bo_move_ttm(struct ttm_buffer_object *bo,
43 		    bool evict,
44 		    bool no_wait_gpu, struct ttm_mem_reg *new_mem)
45 {
46 	struct ttm_tt *ttm = bo->ttm;
47 	struct ttm_mem_reg *old_mem = &bo->mem;
48 	int ret;
49 
50 	if (old_mem->mem_type != TTM_PL_SYSTEM) {
51 		ttm_tt_unbind(ttm);
52 		ttm_bo_free_old_node(bo);
53 		ttm_flag_masked(&old_mem->placement, TTM_PL_FLAG_SYSTEM,
54 				TTM_PL_MASK_MEM);
55 		old_mem->mem_type = TTM_PL_SYSTEM;
56 	}
57 
58 	ret = ttm_tt_set_placement_caching(ttm, new_mem->placement);
59 	if (unlikely(ret != 0))
60 		return ret;
61 
62 	if (new_mem->mem_type != TTM_PL_SYSTEM) {
63 		ret = ttm_tt_bind(ttm, new_mem);
64 		if (unlikely(ret != 0))
65 			return ret;
66 	}
67 
68 	*old_mem = *new_mem;
69 	new_mem->mm_node = NULL;
70 
71 	return 0;
72 }
73 
74 int ttm_mem_io_lock(struct ttm_mem_type_manager *man, bool interruptible)
75 {
76 	if (likely(man->io_reserve_fastpath))
77 		return 0;
78 
79 	if (interruptible) {
80 		if (sx_xlock_sig(&man->io_reserve_mutex))
81 			return (-EINTR);
82 		else
83 			return (0);
84 	}
85 
86 	sx_xlock(&man->io_reserve_mutex);
87 	return 0;
88 }
89 
90 void ttm_mem_io_unlock(struct ttm_mem_type_manager *man)
91 {
92 	if (likely(man->io_reserve_fastpath))
93 		return;
94 
95 	sx_xunlock(&man->io_reserve_mutex);
96 }
97 
98 static int ttm_mem_io_evict(struct ttm_mem_type_manager *man)
99 {
100 	struct ttm_buffer_object *bo;
101 
102 	if (!man->use_io_reserve_lru || list_empty(&man->io_reserve_lru))
103 		return -EAGAIN;
104 
105 	bo = list_first_entry(&man->io_reserve_lru,
106 			      struct ttm_buffer_object,
107 			      io_reserve_lru);
108 	list_del_init(&bo->io_reserve_lru);
109 	ttm_bo_unmap_virtual_locked(bo);
110 
111 	return 0;
112 }
113 
114 static int ttm_mem_io_reserve(struct ttm_bo_device *bdev,
115 			      struct ttm_mem_reg *mem)
116 {
117 	struct ttm_mem_type_manager *man = &bdev->man[mem->mem_type];
118 	int ret = 0;
119 
120 	if (!bdev->driver->io_mem_reserve)
121 		return 0;
122 	if (likely(man->io_reserve_fastpath))
123 		return bdev->driver->io_mem_reserve(bdev, mem);
124 
125 	if (bdev->driver->io_mem_reserve &&
126 	    mem->bus.io_reserved_count++ == 0) {
127 retry:
128 		ret = bdev->driver->io_mem_reserve(bdev, mem);
129 		if (ret == -EAGAIN) {
130 			ret = ttm_mem_io_evict(man);
131 			if (ret == 0)
132 				goto retry;
133 		}
134 	}
135 	return ret;
136 }
137 
138 static void ttm_mem_io_free(struct ttm_bo_device *bdev,
139 			    struct ttm_mem_reg *mem)
140 {
141 	struct ttm_mem_type_manager *man = &bdev->man[mem->mem_type];
142 
143 	if (likely(man->io_reserve_fastpath))
144 		return;
145 
146 	if (bdev->driver->io_mem_reserve &&
147 	    --mem->bus.io_reserved_count == 0 &&
148 	    bdev->driver->io_mem_free)
149 		bdev->driver->io_mem_free(bdev, mem);
150 
151 }
152 
153 int ttm_mem_io_reserve_vm(struct ttm_buffer_object *bo)
154 {
155 	struct ttm_mem_reg *mem = &bo->mem;
156 	int ret;
157 
158 	if (!mem->bus.io_reserved_vm) {
159 		struct ttm_mem_type_manager *man =
160 			&bo->bdev->man[mem->mem_type];
161 
162 		ret = ttm_mem_io_reserve(bo->bdev, mem);
163 		if (unlikely(ret != 0))
164 			return ret;
165 		mem->bus.io_reserved_vm = true;
166 		if (man->use_io_reserve_lru)
167 			list_add_tail(&bo->io_reserve_lru,
168 				      &man->io_reserve_lru);
169 	}
170 	return 0;
171 }
172 
173 void ttm_mem_io_free_vm(struct ttm_buffer_object *bo)
174 {
175 	struct ttm_mem_reg *mem = &bo->mem;
176 
177 	if (mem->bus.io_reserved_vm) {
178 		mem->bus.io_reserved_vm = false;
179 		list_del_init(&bo->io_reserve_lru);
180 		ttm_mem_io_free(bo->bdev, mem);
181 	}
182 }
183 
184 static
185 int ttm_mem_reg_ioremap(struct ttm_bo_device *bdev, struct ttm_mem_reg *mem,
186 			void **virtual)
187 {
188 	struct ttm_mem_type_manager *man = &bdev->man[mem->mem_type];
189 	int ret;
190 	void *addr;
191 
192 	*virtual = NULL;
193 	(void) ttm_mem_io_lock(man, false);
194 	ret = ttm_mem_io_reserve(bdev, mem);
195 	ttm_mem_io_unlock(man);
196 	if (ret || !mem->bus.is_iomem)
197 		return ret;
198 
199 	if (mem->bus.addr) {
200 		addr = mem->bus.addr;
201 	} else {
202 		addr = pmap_mapdev_attr(mem->bus.base + mem->bus.offset,
203 		    mem->bus.size, (mem->placement & TTM_PL_FLAG_WC) ?
204 		    VM_MEMATTR_WRITE_COMBINING : VM_MEMATTR_UNCACHEABLE);
205 		if (!addr) {
206 			(void) ttm_mem_io_lock(man, false);
207 			ttm_mem_io_free(bdev, mem);
208 			ttm_mem_io_unlock(man);
209 			return -ENOMEM;
210 		}
211 	}
212 	*virtual = addr;
213 	return 0;
214 }
215 
216 static
217 void ttm_mem_reg_iounmap(struct ttm_bo_device *bdev, struct ttm_mem_reg *mem,
218 			 void *virtual)
219 {
220 	struct ttm_mem_type_manager *man;
221 
222 	man = &bdev->man[mem->mem_type];
223 
224 	if (virtual && mem->bus.addr == NULL)
225 		pmap_unmapdev(virtual, mem->bus.size);
226 	(void) ttm_mem_io_lock(man, false);
227 	ttm_mem_io_free(bdev, mem);
228 	ttm_mem_io_unlock(man);
229 }
230 
231 static int ttm_copy_io_page(void *dst, void *src, unsigned long page)
232 {
233 	uint32_t *dstP =
234 	    (uint32_t *) ((unsigned long)dst + (page << PAGE_SHIFT));
235 	uint32_t *srcP =
236 	    (uint32_t *) ((unsigned long)src + (page << PAGE_SHIFT));
237 
238 	int i;
239 	for (i = 0; i < PAGE_SIZE / sizeof(uint32_t); ++i)
240 		/* iowrite32(ioread32(srcP++), dstP++); */
241 		*dstP++ = *srcP++;
242 	return 0;
243 }
244 
245 static int ttm_copy_io_ttm_page(struct ttm_tt *ttm, void *src,
246 				unsigned long page,
247 				vm_memattr_t prot)
248 {
249 	vm_page_t d = ttm->pages[page];
250 	void *dst;
251 
252 	if (!d)
253 		return -ENOMEM;
254 
255 	src = (void *)((unsigned long)src + (page << PAGE_SHIFT));
256 
257 	/* XXXKIB can't sleep ? */
258 	dst = pmap_mapdev_attr(VM_PAGE_TO_PHYS(d), PAGE_SIZE, prot);
259 	if (!dst)
260 		return -ENOMEM;
261 
262 	memcpy(dst, src, PAGE_SIZE);
263 
264 	pmap_unmapdev(dst, PAGE_SIZE);
265 
266 	return 0;
267 }
268 
269 static int ttm_copy_ttm_io_page(struct ttm_tt *ttm, void *dst,
270 				unsigned long page,
271 				vm_memattr_t prot)
272 {
273 	vm_page_t s = ttm->pages[page];
274 	void *src;
275 
276 	if (!s)
277 		return -ENOMEM;
278 
279 	dst = (void *)((unsigned long)dst + (page << PAGE_SHIFT));
280 	src = pmap_mapdev_attr(VM_PAGE_TO_PHYS(s), PAGE_SIZE, prot);
281 	if (!src)
282 		return -ENOMEM;
283 
284 	memcpy(dst, src, PAGE_SIZE);
285 
286 	pmap_unmapdev(src, PAGE_SIZE);
287 
288 	return 0;
289 }
290 
291 int ttm_bo_move_memcpy(struct ttm_buffer_object *bo,
292 		       bool evict, bool no_wait_gpu,
293 		       struct ttm_mem_reg *new_mem)
294 {
295 	struct ttm_bo_device *bdev = bo->bdev;
296 	struct ttm_mem_type_manager *man = &bdev->man[new_mem->mem_type];
297 	struct ttm_tt *ttm = bo->ttm;
298 	struct ttm_mem_reg *old_mem = &bo->mem;
299 	struct ttm_mem_reg old_copy = *old_mem;
300 	void *old_iomap;
301 	void *new_iomap;
302 	int ret;
303 	unsigned long i;
304 	unsigned long page;
305 	unsigned long add = 0;
306 	int dir;
307 
308 	ret = ttm_mem_reg_ioremap(bdev, old_mem, &old_iomap);
309 	if (ret)
310 		return ret;
311 	ret = ttm_mem_reg_ioremap(bdev, new_mem, &new_iomap);
312 	if (ret)
313 		goto out;
314 
315 	if (old_iomap == NULL && new_iomap == NULL)
316 		goto out2;
317 	if (old_iomap == NULL && ttm == NULL)
318 		goto out2;
319 
320 	if (ttm->state == tt_unpopulated) {
321 		ret = ttm->bdev->driver->ttm_tt_populate(ttm);
322 		if (ret) {
323 			/* if we fail here don't nuke the mm node
324 			 * as the bo still owns it */
325 			old_copy.mm_node = NULL;
326 			goto out1;
327 		}
328 	}
329 
330 	add = 0;
331 	dir = 1;
332 
333 	if ((old_mem->mem_type == new_mem->mem_type) &&
334 	    (new_mem->start < old_mem->start + old_mem->size)) {
335 		dir = -1;
336 		add = new_mem->num_pages - 1;
337 	}
338 
339 	for (i = 0; i < new_mem->num_pages; ++i) {
340 		page = i * dir + add;
341 		if (old_iomap == NULL) {
342 			vm_memattr_t prot = ttm_io_prot(old_mem->placement);
343 			ret = ttm_copy_ttm_io_page(ttm, new_iomap, page,
344 						   prot);
345 		} else if (new_iomap == NULL) {
346 			vm_memattr_t prot = ttm_io_prot(new_mem->placement);
347 			ret = ttm_copy_io_ttm_page(ttm, old_iomap, page,
348 						   prot);
349 		} else
350 			ret = ttm_copy_io_page(new_iomap, old_iomap, page);
351 		if (ret) {
352 			/* failing here, means keep old copy as-is */
353 			old_copy.mm_node = NULL;
354 			goto out1;
355 		}
356 	}
357 	mb();
358 out2:
359 	old_copy = *old_mem;
360 	*old_mem = *new_mem;
361 	new_mem->mm_node = NULL;
362 
363 	if ((man->flags & TTM_MEMTYPE_FLAG_FIXED) && (ttm != NULL)) {
364 		ttm_tt_unbind(ttm);
365 		ttm_tt_destroy(ttm);
366 		bo->ttm = NULL;
367 	}
368 
369 out1:
370 	ttm_mem_reg_iounmap(bdev, old_mem, new_iomap);
371 out:
372 	ttm_mem_reg_iounmap(bdev, &old_copy, old_iomap);
373 	ttm_bo_mem_put(bo, &old_copy);
374 	return ret;
375 }
376 
377 MALLOC_DEFINE(M_TTM_TRANSF_OBJ, "ttm_transf_obj", "TTM Transfer Objects");
378 
379 static void ttm_transfered_destroy(struct ttm_buffer_object *bo)
380 {
381 	free(bo, M_TTM_TRANSF_OBJ);
382 }
383 
384 /**
385  * ttm_buffer_object_transfer
386  *
387  * @bo: A pointer to a struct ttm_buffer_object.
388  * @new_obj: A pointer to a pointer to a newly created ttm_buffer_object,
389  * holding the data of @bo with the old placement.
390  *
391  * This is a utility function that may be called after an accelerated move
392  * has been scheduled. A new buffer object is created as a placeholder for
393  * the old data while it's being copied. When that buffer object is idle,
394  * it can be destroyed, releasing the space of the old placement.
395  * Returns:
396  * !0: Failure.
397  */
398 
399 static int
400 ttm_buffer_object_transfer(struct ttm_buffer_object *bo,
401     struct ttm_buffer_object **new_obj)
402 {
403 	struct ttm_buffer_object *fbo;
404 	struct ttm_bo_device *bdev = bo->bdev;
405 	struct ttm_bo_driver *driver = bdev->driver;
406 
407 	fbo = malloc(sizeof(*fbo), M_TTM_TRANSF_OBJ, M_WAITOK);
408 	*fbo = *bo;
409 
410 	/**
411 	 * Fix up members that we shouldn't copy directly:
412 	 * TODO: Explicit member copy would probably be better here.
413 	 */
414 
415 	INIT_LIST_HEAD(&fbo->ddestroy);
416 	INIT_LIST_HEAD(&fbo->lru);
417 	INIT_LIST_HEAD(&fbo->swap);
418 	INIT_LIST_HEAD(&fbo->io_reserve_lru);
419 	fbo->vm_node = NULL;
420 	atomic_set(&fbo->cpu_writers, 0);
421 
422 	mtx_lock(&bdev->fence_lock);
423 	if (bo->sync_obj)
424 		fbo->sync_obj = driver->sync_obj_ref(bo->sync_obj);
425 	else
426 		fbo->sync_obj = NULL;
427 	mtx_unlock(&bdev->fence_lock);
428 	refcount_init(&fbo->list_kref, 1);
429 	refcount_init(&fbo->kref, 1);
430 	fbo->destroy = &ttm_transfered_destroy;
431 	fbo->acc_size = 0;
432 
433 	*new_obj = fbo;
434 	return 0;
435 }
436 
437 vm_memattr_t
438 ttm_io_prot(uint32_t caching_flags)
439 {
440 #if defined(__i386__) || defined(__amd64__) || defined(__powerpc__) || 	\
441  defined(__arm__)
442 	if (caching_flags & TTM_PL_FLAG_WC)
443 		return (VM_MEMATTR_WRITE_COMBINING);
444 	else
445 		/*
446 		 * We do not support i386, look at the linux source
447 		 * for the reason of the comment.
448 		 */
449 		return (VM_MEMATTR_UNCACHEABLE);
450 #else
451 #error Port me
452 #endif
453 }
454 
455 static int ttm_bo_ioremap(struct ttm_buffer_object *bo,
456 			  unsigned long offset,
457 			  unsigned long size,
458 			  struct ttm_bo_kmap_obj *map)
459 {
460 	struct ttm_mem_reg *mem = &bo->mem;
461 
462 	if (bo->mem.bus.addr) {
463 		map->bo_kmap_type = ttm_bo_map_premapped;
464 		map->virtual = (void *)(((u8 *)bo->mem.bus.addr) + offset);
465 	} else {
466 		map->bo_kmap_type = ttm_bo_map_iomap;
467 		map->virtual = pmap_mapdev_attr(bo->mem.bus.base +
468 		    bo->mem.bus.offset + offset, size,
469 		    (mem->placement & TTM_PL_FLAG_WC) ?
470 		    VM_MEMATTR_WRITE_COMBINING : VM_MEMATTR_UNCACHEABLE);
471 		map->size = size;
472 	}
473 	return (!map->virtual) ? -ENOMEM : 0;
474 }
475 
476 static int ttm_bo_kmap_ttm(struct ttm_buffer_object *bo,
477 			   unsigned long start_page,
478 			   unsigned long num_pages,
479 			   struct ttm_bo_kmap_obj *map)
480 {
481 	struct ttm_mem_reg *mem = &bo->mem;
482 	vm_memattr_t prot;
483 	struct ttm_tt *ttm = bo->ttm;
484 	int i, ret;
485 
486 	MPASS(ttm != NULL);
487 
488 	if (ttm->state == tt_unpopulated) {
489 		ret = ttm->bdev->driver->ttm_tt_populate(ttm);
490 		if (ret)
491 			return ret;
492 	}
493 
494 	if (num_pages == 1 && (mem->placement & TTM_PL_FLAG_CACHED)) {
495 		/*
496 		 * We're mapping a single page, and the desired
497 		 * page protection is consistent with the bo.
498 		 */
499 
500 		map->bo_kmap_type = ttm_bo_map_kmap;
501 		map->page = ttm->pages[start_page];
502 		map->sf = sf_buf_alloc(map->page, 0);
503 		map->virtual = (void *)sf_buf_kva(map->sf);
504 	} else {
505 		/*
506 		 * We need to use vmap to get the desired page protection
507 		 * or to make the buffer object look contiguous.
508 		 */
509 		prot = (mem->placement & TTM_PL_FLAG_CACHED) ?
510 			VM_MEMATTR_DEFAULT : ttm_io_prot(mem->placement);
511 		map->bo_kmap_type = ttm_bo_map_vmap;
512 		map->num_pages = num_pages;
513 		map->virtual = (void *)kva_alloc(num_pages * PAGE_SIZE);
514 		if (map->virtual != NULL) {
515 			for (i = 0; i < num_pages; i++) {
516 				/* XXXKIB hack */
517 				pmap_page_set_memattr(ttm->pages[start_page +
518 				    i], prot);
519 			}
520 			pmap_qenter((vm_offset_t)map->virtual,
521 			    &ttm->pages[start_page], num_pages);
522 		}
523 	}
524 	return (!map->virtual) ? -ENOMEM : 0;
525 }
526 
527 int ttm_bo_kmap(struct ttm_buffer_object *bo,
528 		unsigned long start_page, unsigned long num_pages,
529 		struct ttm_bo_kmap_obj *map)
530 {
531 	struct ttm_mem_type_manager *man =
532 		&bo->bdev->man[bo->mem.mem_type];
533 	unsigned long offset, size;
534 	int ret;
535 
536 	MPASS(list_empty(&bo->swap));
537 	map->virtual = NULL;
538 	map->bo = bo;
539 	if (num_pages > bo->num_pages)
540 		return -EINVAL;
541 	if (start_page > bo->num_pages)
542 		return -EINVAL;
543 #if 0
544 	if (num_pages > 1 && !DRM_SUSER(DRM_CURPROC))
545 		return -EPERM;
546 #endif
547 	(void) ttm_mem_io_lock(man, false);
548 	ret = ttm_mem_io_reserve(bo->bdev, &bo->mem);
549 	ttm_mem_io_unlock(man);
550 	if (ret)
551 		return ret;
552 	if (!bo->mem.bus.is_iomem) {
553 		return ttm_bo_kmap_ttm(bo, start_page, num_pages, map);
554 	} else {
555 		offset = start_page << PAGE_SHIFT;
556 		size = num_pages << PAGE_SHIFT;
557 		return ttm_bo_ioremap(bo, offset, size, map);
558 	}
559 }
560 
561 void ttm_bo_kunmap(struct ttm_bo_kmap_obj *map)
562 {
563 	struct ttm_buffer_object *bo = map->bo;
564 	struct ttm_mem_type_manager *man =
565 		&bo->bdev->man[bo->mem.mem_type];
566 
567 	if (!map->virtual)
568 		return;
569 	switch (map->bo_kmap_type) {
570 	case ttm_bo_map_iomap:
571 		pmap_unmapdev(map->virtual, map->size);
572 		break;
573 	case ttm_bo_map_vmap:
574 		pmap_qremove((vm_offset_t)(map->virtual), map->num_pages);
575 		kva_free((vm_offset_t)map->virtual,
576 		    map->num_pages * PAGE_SIZE);
577 		break;
578 	case ttm_bo_map_kmap:
579 		sf_buf_free(map->sf);
580 		break;
581 	case ttm_bo_map_premapped:
582 		break;
583 	default:
584 		MPASS(0);
585 	}
586 	(void) ttm_mem_io_lock(man, false);
587 	ttm_mem_io_free(map->bo->bdev, &map->bo->mem);
588 	ttm_mem_io_unlock(man);
589 	map->virtual = NULL;
590 	map->page = NULL;
591 	map->sf = NULL;
592 }
593 
594 int ttm_bo_move_accel_cleanup(struct ttm_buffer_object *bo,
595 			      void *sync_obj,
596 			      bool evict,
597 			      bool no_wait_gpu,
598 			      struct ttm_mem_reg *new_mem)
599 {
600 	struct ttm_bo_device *bdev = bo->bdev;
601 	struct ttm_bo_driver *driver = bdev->driver;
602 	struct ttm_mem_type_manager *man = &bdev->man[new_mem->mem_type];
603 	struct ttm_mem_reg *old_mem = &bo->mem;
604 	int ret;
605 	struct ttm_buffer_object *ghost_obj;
606 	void *tmp_obj = NULL;
607 
608 	mtx_lock(&bdev->fence_lock);
609 	if (bo->sync_obj) {
610 		tmp_obj = bo->sync_obj;
611 		bo->sync_obj = NULL;
612 	}
613 	bo->sync_obj = driver->sync_obj_ref(sync_obj);
614 	if (evict) {
615 		ret = ttm_bo_wait(bo, false, false, false);
616 		mtx_unlock(&bdev->fence_lock);
617 		if (tmp_obj)
618 			driver->sync_obj_unref(&tmp_obj);
619 		if (ret)
620 			return ret;
621 
622 		if ((man->flags & TTM_MEMTYPE_FLAG_FIXED) &&
623 		    (bo->ttm != NULL)) {
624 			ttm_tt_unbind(bo->ttm);
625 			ttm_tt_destroy(bo->ttm);
626 			bo->ttm = NULL;
627 		}
628 		ttm_bo_free_old_node(bo);
629 	} else {
630 		/**
631 		 * This should help pipeline ordinary buffer moves.
632 		 *
633 		 * Hang old buffer memory on a new buffer object,
634 		 * and leave it to be released when the GPU
635 		 * operation has completed.
636 		 */
637 
638 		set_bit(TTM_BO_PRIV_FLAG_MOVING, &bo->priv_flags);
639 		mtx_unlock(&bdev->fence_lock);
640 		if (tmp_obj)
641 			driver->sync_obj_unref(&tmp_obj);
642 
643 		ret = ttm_buffer_object_transfer(bo, &ghost_obj);
644 		if (ret)
645 			return ret;
646 
647 		/**
648 		 * If we're not moving to fixed memory, the TTM object
649 		 * needs to stay alive. Otherwhise hang it on the ghost
650 		 * bo to be unbound and destroyed.
651 		 */
652 
653 		if (!(man->flags & TTM_MEMTYPE_FLAG_FIXED))
654 			ghost_obj->ttm = NULL;
655 		else
656 			bo->ttm = NULL;
657 
658 		ttm_bo_unreserve(ghost_obj);
659 		ttm_bo_unref(&ghost_obj);
660 	}
661 
662 	*old_mem = *new_mem;
663 	new_mem->mm_node = NULL;
664 
665 	return 0;
666 }
667