Linux-libre 5.4.49-gnu
[librecmc/linux-libre.git] / drivers / gpu / drm / ttm / ttm_bo.c
1 /* SPDX-License-Identifier: GPL-2.0 OR MIT */
2 /**************************************************************************
3  *
4  * Copyright (c) 2006-2009 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 #define pr_fmt(fmt) "[TTM] " fmt
33
34 #include <drm/ttm/ttm_module.h>
35 #include <drm/ttm/ttm_bo_driver.h>
36 #include <drm/ttm/ttm_placement.h>
37 #include <linux/jiffies.h>
38 #include <linux/slab.h>
39 #include <linux/sched.h>
40 #include <linux/mm.h>
41 #include <linux/file.h>
42 #include <linux/module.h>
43 #include <linux/atomic.h>
44 #include <linux/dma-resv.h>
45
46 static void ttm_bo_global_kobj_release(struct kobject *kobj);
47
48 /**
49  * ttm_global_mutex - protecting the global BO state
50  */
51 DEFINE_MUTEX(ttm_global_mutex);
52 unsigned ttm_bo_glob_use_count;
53 struct ttm_bo_global ttm_bo_glob;
54
55 static struct attribute ttm_bo_count = {
56         .name = "bo_count",
57         .mode = S_IRUGO
58 };
59
60 /* default destructor */
61 static void ttm_bo_default_destroy(struct ttm_buffer_object *bo)
62 {
63         kfree(bo);
64 }
65
66 static inline int ttm_mem_type_from_place(const struct ttm_place *place,
67                                           uint32_t *mem_type)
68 {
69         int pos;
70
71         pos = ffs(place->flags & TTM_PL_MASK_MEM);
72         if (unlikely(!pos))
73                 return -EINVAL;
74
75         *mem_type = pos - 1;
76         return 0;
77 }
78
79 static void ttm_mem_type_debug(struct ttm_bo_device *bdev, struct drm_printer *p,
80                                int mem_type)
81 {
82         struct ttm_mem_type_manager *man = &bdev->man[mem_type];
83
84         drm_printf(p, "    has_type: %d\n", man->has_type);
85         drm_printf(p, "    use_type: %d\n", man->use_type);
86         drm_printf(p, "    flags: 0x%08X\n", man->flags);
87         drm_printf(p, "    gpu_offset: 0x%08llX\n", man->gpu_offset);
88         drm_printf(p, "    size: %llu\n", man->size);
89         drm_printf(p, "    available_caching: 0x%08X\n", man->available_caching);
90         drm_printf(p, "    default_caching: 0x%08X\n", man->default_caching);
91         if (mem_type != TTM_PL_SYSTEM)
92                 (*man->func->debug)(man, p);
93 }
94
95 static void ttm_bo_mem_space_debug(struct ttm_buffer_object *bo,
96                                         struct ttm_placement *placement)
97 {
98         struct drm_printer p = drm_debug_printer(TTM_PFX);
99         int i, ret, mem_type;
100
101         drm_printf(&p, "No space for %p (%lu pages, %luK, %luM)\n",
102                    bo, bo->mem.num_pages, bo->mem.size >> 10,
103                    bo->mem.size >> 20);
104         for (i = 0; i < placement->num_placement; i++) {
105                 ret = ttm_mem_type_from_place(&placement->placement[i],
106                                                 &mem_type);
107                 if (ret)
108                         return;
109                 drm_printf(&p, "  placement[%d]=0x%08X (%d)\n",
110                            i, placement->placement[i].flags, mem_type);
111                 ttm_mem_type_debug(bo->bdev, &p, mem_type);
112         }
113 }
114
115 static ssize_t ttm_bo_global_show(struct kobject *kobj,
116                                   struct attribute *attr,
117                                   char *buffer)
118 {
119         struct ttm_bo_global *glob =
120                 container_of(kobj, struct ttm_bo_global, kobj);
121
122         return snprintf(buffer, PAGE_SIZE, "%d\n",
123                                 atomic_read(&glob->bo_count));
124 }
125
126 static struct attribute *ttm_bo_global_attrs[] = {
127         &ttm_bo_count,
128         NULL
129 };
130
131 static const struct sysfs_ops ttm_bo_global_ops = {
132         .show = &ttm_bo_global_show
133 };
134
135 static struct kobj_type ttm_bo_glob_kobj_type  = {
136         .release = &ttm_bo_global_kobj_release,
137         .sysfs_ops = &ttm_bo_global_ops,
138         .default_attrs = ttm_bo_global_attrs
139 };
140
141
142 static inline uint32_t ttm_bo_type_flags(unsigned type)
143 {
144         return 1 << (type);
145 }
146
147 static void ttm_bo_release_list(struct kref *list_kref)
148 {
149         struct ttm_buffer_object *bo =
150             container_of(list_kref, struct ttm_buffer_object, list_kref);
151         struct ttm_bo_device *bdev = bo->bdev;
152         size_t acc_size = bo->acc_size;
153
154         BUG_ON(kref_read(&bo->list_kref));
155         BUG_ON(kref_read(&bo->kref));
156         BUG_ON(atomic_read(&bo->cpu_writers));
157         BUG_ON(bo->mem.mm_node != NULL);
158         BUG_ON(!list_empty(&bo->lru));
159         BUG_ON(!list_empty(&bo->ddestroy));
160         ttm_tt_destroy(bo->ttm);
161         atomic_dec(&bo->bdev->glob->bo_count);
162         dma_fence_put(bo->moving);
163         if (!ttm_bo_uses_embedded_gem_object(bo))
164                 dma_resv_fini(&bo->base._resv);
165         mutex_destroy(&bo->wu_mutex);
166         bo->destroy(bo);
167         ttm_mem_global_free(bdev->glob->mem_glob, acc_size);
168 }
169
170 static void ttm_bo_add_mem_to_lru(struct ttm_buffer_object *bo,
171                                   struct ttm_mem_reg *mem)
172 {
173         struct ttm_bo_device *bdev = bo->bdev;
174         struct ttm_mem_type_manager *man;
175
176         dma_resv_assert_held(bo->base.resv);
177
178         if (!list_empty(&bo->lru))
179                 return;
180
181         if (mem->placement & TTM_PL_FLAG_NO_EVICT)
182                 return;
183
184         man = &bdev->man[mem->mem_type];
185         list_add_tail(&bo->lru, &man->lru[bo->priority]);
186         kref_get(&bo->list_kref);
187
188         if (!(man->flags & TTM_MEMTYPE_FLAG_FIXED) && bo->ttm &&
189             !(bo->ttm->page_flags & (TTM_PAGE_FLAG_SG |
190                                      TTM_PAGE_FLAG_SWAPPED))) {
191                 list_add_tail(&bo->swap, &bdev->glob->swap_lru[bo->priority]);
192                 kref_get(&bo->list_kref);
193         }
194 }
195
196 void ttm_bo_add_to_lru(struct ttm_buffer_object *bo)
197 {
198         ttm_bo_add_mem_to_lru(bo, &bo->mem);
199 }
200 EXPORT_SYMBOL(ttm_bo_add_to_lru);
201
202 static void ttm_bo_ref_bug(struct kref *list_kref)
203 {
204         BUG();
205 }
206
207 void ttm_bo_del_from_lru(struct ttm_buffer_object *bo)
208 {
209         struct ttm_bo_device *bdev = bo->bdev;
210         bool notify = false;
211
212         if (!list_empty(&bo->swap)) {
213                 list_del_init(&bo->swap);
214                 kref_put(&bo->list_kref, ttm_bo_ref_bug);
215                 notify = true;
216         }
217         if (!list_empty(&bo->lru)) {
218                 list_del_init(&bo->lru);
219                 kref_put(&bo->list_kref, ttm_bo_ref_bug);
220                 notify = true;
221         }
222
223         if (notify && bdev->driver->del_from_lru_notify)
224                 bdev->driver->del_from_lru_notify(bo);
225 }
226
227 void ttm_bo_del_sub_from_lru(struct ttm_buffer_object *bo)
228 {
229         struct ttm_bo_global *glob = bo->bdev->glob;
230
231         spin_lock(&glob->lru_lock);
232         ttm_bo_del_from_lru(bo);
233         spin_unlock(&glob->lru_lock);
234 }
235 EXPORT_SYMBOL(ttm_bo_del_sub_from_lru);
236
237 static void ttm_bo_bulk_move_set_pos(struct ttm_lru_bulk_move_pos *pos,
238                                      struct ttm_buffer_object *bo)
239 {
240         if (!pos->first)
241                 pos->first = bo;
242         pos->last = bo;
243 }
244
245 void ttm_bo_move_to_lru_tail(struct ttm_buffer_object *bo,
246                              struct ttm_lru_bulk_move *bulk)
247 {
248         dma_resv_assert_held(bo->base.resv);
249
250         ttm_bo_del_from_lru(bo);
251         ttm_bo_add_to_lru(bo);
252
253         if (bulk && !(bo->mem.placement & TTM_PL_FLAG_NO_EVICT)) {
254                 switch (bo->mem.mem_type) {
255                 case TTM_PL_TT:
256                         ttm_bo_bulk_move_set_pos(&bulk->tt[bo->priority], bo);
257                         break;
258
259                 case TTM_PL_VRAM:
260                         ttm_bo_bulk_move_set_pos(&bulk->vram[bo->priority], bo);
261                         break;
262                 }
263                 if (bo->ttm && !(bo->ttm->page_flags &
264                                  (TTM_PAGE_FLAG_SG | TTM_PAGE_FLAG_SWAPPED)))
265                         ttm_bo_bulk_move_set_pos(&bulk->swap[bo->priority], bo);
266         }
267 }
268 EXPORT_SYMBOL(ttm_bo_move_to_lru_tail);
269
270 void ttm_bo_bulk_move_lru_tail(struct ttm_lru_bulk_move *bulk)
271 {
272         unsigned i;
273
274         for (i = 0; i < TTM_MAX_BO_PRIORITY; ++i) {
275                 struct ttm_lru_bulk_move_pos *pos = &bulk->tt[i];
276                 struct ttm_mem_type_manager *man;
277
278                 if (!pos->first)
279                         continue;
280
281                 dma_resv_assert_held(pos->first->base.resv);
282                 dma_resv_assert_held(pos->last->base.resv);
283
284                 man = &pos->first->bdev->man[TTM_PL_TT];
285                 list_bulk_move_tail(&man->lru[i], &pos->first->lru,
286                                     &pos->last->lru);
287         }
288
289         for (i = 0; i < TTM_MAX_BO_PRIORITY; ++i) {
290                 struct ttm_lru_bulk_move_pos *pos = &bulk->vram[i];
291                 struct ttm_mem_type_manager *man;
292
293                 if (!pos->first)
294                         continue;
295
296                 dma_resv_assert_held(pos->first->base.resv);
297                 dma_resv_assert_held(pos->last->base.resv);
298
299                 man = &pos->first->bdev->man[TTM_PL_VRAM];
300                 list_bulk_move_tail(&man->lru[i], &pos->first->lru,
301                                     &pos->last->lru);
302         }
303
304         for (i = 0; i < TTM_MAX_BO_PRIORITY; ++i) {
305                 struct ttm_lru_bulk_move_pos *pos = &bulk->swap[i];
306                 struct list_head *lru;
307
308                 if (!pos->first)
309                         continue;
310
311                 dma_resv_assert_held(pos->first->base.resv);
312                 dma_resv_assert_held(pos->last->base.resv);
313
314                 lru = &pos->first->bdev->glob->swap_lru[i];
315                 list_bulk_move_tail(lru, &pos->first->swap, &pos->last->swap);
316         }
317 }
318 EXPORT_SYMBOL(ttm_bo_bulk_move_lru_tail);
319
320 static int ttm_bo_handle_move_mem(struct ttm_buffer_object *bo,
321                                   struct ttm_mem_reg *mem, bool evict,
322                                   struct ttm_operation_ctx *ctx)
323 {
324         struct ttm_bo_device *bdev = bo->bdev;
325         bool old_is_pci = ttm_mem_reg_is_pci(bdev, &bo->mem);
326         bool new_is_pci = ttm_mem_reg_is_pci(bdev, mem);
327         struct ttm_mem_type_manager *old_man = &bdev->man[bo->mem.mem_type];
328         struct ttm_mem_type_manager *new_man = &bdev->man[mem->mem_type];
329         int ret = 0;
330
331         if (old_is_pci || new_is_pci ||
332             ((mem->placement & bo->mem.placement & TTM_PL_MASK_CACHING) == 0)) {
333                 ret = ttm_mem_io_lock(old_man, true);
334                 if (unlikely(ret != 0))
335                         goto out_err;
336                 ttm_bo_unmap_virtual_locked(bo);
337                 ttm_mem_io_unlock(old_man);
338         }
339
340         /*
341          * Create and bind a ttm if required.
342          */
343
344         if (!(new_man->flags & TTM_MEMTYPE_FLAG_FIXED)) {
345                 if (bo->ttm == NULL) {
346                         bool zero = !(old_man->flags & TTM_MEMTYPE_FLAG_FIXED);
347                         ret = ttm_tt_create(bo, zero);
348                         if (ret)
349                                 goto out_err;
350                 }
351
352                 ret = ttm_tt_set_placement_caching(bo->ttm, mem->placement);
353                 if (ret)
354                         goto out_err;
355
356                 if (mem->mem_type != TTM_PL_SYSTEM) {
357                         ret = ttm_tt_bind(bo->ttm, mem, ctx);
358                         if (ret)
359                                 goto out_err;
360                 }
361
362                 if (bo->mem.mem_type == TTM_PL_SYSTEM) {
363                         if (bdev->driver->move_notify)
364                                 bdev->driver->move_notify(bo, evict, mem);
365                         bo->mem = *mem;
366                         mem->mm_node = NULL;
367                         goto moved;
368                 }
369         }
370
371         if (bdev->driver->move_notify)
372                 bdev->driver->move_notify(bo, evict, mem);
373
374         if (!(old_man->flags & TTM_MEMTYPE_FLAG_FIXED) &&
375             !(new_man->flags & TTM_MEMTYPE_FLAG_FIXED))
376                 ret = ttm_bo_move_ttm(bo, ctx, mem);
377         else if (bdev->driver->move)
378                 ret = bdev->driver->move(bo, evict, ctx, mem);
379         else
380                 ret = ttm_bo_move_memcpy(bo, ctx, mem);
381
382         if (ret) {
383                 if (bdev->driver->move_notify) {
384                         swap(*mem, bo->mem);
385                         bdev->driver->move_notify(bo, false, mem);
386                         swap(*mem, bo->mem);
387                 }
388
389                 goto out_err;
390         }
391
392 moved:
393         if (bo->evicted) {
394                 if (bdev->driver->invalidate_caches) {
395                         ret = bdev->driver->invalidate_caches(bdev, bo->mem.placement);
396                         if (ret)
397                                 pr_err("Can not flush read caches\n");
398                 }
399                 bo->evicted = false;
400         }
401
402         if (bo->mem.mm_node)
403                 bo->offset = (bo->mem.start << PAGE_SHIFT) +
404                     bdev->man[bo->mem.mem_type].gpu_offset;
405         else
406                 bo->offset = 0;
407
408         ctx->bytes_moved += bo->num_pages << PAGE_SHIFT;
409         return 0;
410
411 out_err:
412         new_man = &bdev->man[bo->mem.mem_type];
413         if (new_man->flags & TTM_MEMTYPE_FLAG_FIXED) {
414                 ttm_tt_destroy(bo->ttm);
415                 bo->ttm = NULL;
416         }
417
418         return ret;
419 }
420
421 /**
422  * Call bo::reserved.
423  * Will release GPU memory type usage on destruction.
424  * This is the place to put in driver specific hooks to release
425  * driver private resources.
426  * Will release the bo::reserved lock.
427  */
428
429 static void ttm_bo_cleanup_memtype_use(struct ttm_buffer_object *bo)
430 {
431         if (bo->bdev->driver->move_notify)
432                 bo->bdev->driver->move_notify(bo, false, NULL);
433
434         ttm_tt_destroy(bo->ttm);
435         bo->ttm = NULL;
436         ttm_bo_mem_put(bo, &bo->mem);
437 }
438
439 static int ttm_bo_individualize_resv(struct ttm_buffer_object *bo)
440 {
441         int r;
442
443         if (bo->base.resv == &bo->base._resv)
444                 return 0;
445
446         BUG_ON(!dma_resv_trylock(&bo->base._resv));
447
448         r = dma_resv_copy_fences(&bo->base._resv, bo->base.resv);
449         if (r)
450                 dma_resv_unlock(&bo->base._resv);
451
452         return r;
453 }
454
455 static void ttm_bo_flush_all_fences(struct ttm_buffer_object *bo)
456 {
457         struct dma_resv_list *fobj;
458         struct dma_fence *fence;
459         int i;
460
461         fobj = dma_resv_get_list(&bo->base._resv);
462         fence = dma_resv_get_excl(&bo->base._resv);
463         if (fence && !fence->ops->signaled)
464                 dma_fence_enable_sw_signaling(fence);
465
466         for (i = 0; fobj && i < fobj->shared_count; ++i) {
467                 fence = rcu_dereference_protected(fobj->shared[i],
468                                         dma_resv_held(bo->base.resv));
469
470                 if (!fence->ops->signaled)
471                         dma_fence_enable_sw_signaling(fence);
472         }
473 }
474
475 static void ttm_bo_cleanup_refs_or_queue(struct ttm_buffer_object *bo)
476 {
477         struct ttm_bo_device *bdev = bo->bdev;
478         struct ttm_bo_global *glob = bdev->glob;
479         int ret;
480
481         ret = ttm_bo_individualize_resv(bo);
482         if (ret) {
483                 /* Last resort, if we fail to allocate memory for the
484                  * fences block for the BO to become idle
485                  */
486                 dma_resv_wait_timeout_rcu(bo->base.resv, true, false,
487                                                     30 * HZ);
488                 spin_lock(&glob->lru_lock);
489                 goto error;
490         }
491
492         spin_lock(&glob->lru_lock);
493         ret = dma_resv_trylock(bo->base.resv) ? 0 : -EBUSY;
494         if (!ret) {
495                 if (dma_resv_test_signaled_rcu(&bo->base._resv, true)) {
496                         ttm_bo_del_from_lru(bo);
497                         spin_unlock(&glob->lru_lock);
498                         if (bo->base.resv != &bo->base._resv)
499                                 dma_resv_unlock(&bo->base._resv);
500
501                         ttm_bo_cleanup_memtype_use(bo);
502                         dma_resv_unlock(bo->base.resv);
503                         return;
504                 }
505
506                 ttm_bo_flush_all_fences(bo);
507
508                 /*
509                  * Make NO_EVICT bos immediately available to
510                  * shrinkers, now that they are queued for
511                  * destruction.
512                  */
513                 if (bo->mem.placement & TTM_PL_FLAG_NO_EVICT) {
514                         bo->mem.placement &= ~TTM_PL_FLAG_NO_EVICT;
515                         ttm_bo_add_to_lru(bo);
516                 }
517
518                 dma_resv_unlock(bo->base.resv);
519         }
520         if (bo->base.resv != &bo->base._resv) {
521                 ttm_bo_flush_all_fences(bo);
522                 dma_resv_unlock(&bo->base._resv);
523         }
524
525 error:
526         kref_get(&bo->list_kref);
527         list_add_tail(&bo->ddestroy, &bdev->ddestroy);
528         spin_unlock(&glob->lru_lock);
529
530         schedule_delayed_work(&bdev->wq,
531                               ((HZ / 100) < 1) ? 1 : HZ / 100);
532 }
533
534 /**
535  * function ttm_bo_cleanup_refs
536  * If bo idle, remove from delayed- and lru lists, and unref.
537  * If not idle, do nothing.
538  *
539  * Must be called with lru_lock and reservation held, this function
540  * will drop the lru lock and optionally the reservation lock before returning.
541  *
542  * @interruptible         Any sleeps should occur interruptibly.
543  * @no_wait_gpu           Never wait for gpu. Return -EBUSY instead.
544  * @unlock_resv           Unlock the reservation lock as well.
545  */
546
547 static int ttm_bo_cleanup_refs(struct ttm_buffer_object *bo,
548                                bool interruptible, bool no_wait_gpu,
549                                bool unlock_resv)
550 {
551         struct ttm_bo_global *glob = bo->bdev->glob;
552         struct dma_resv *resv;
553         int ret;
554
555         if (unlikely(list_empty(&bo->ddestroy)))
556                 resv = bo->base.resv;
557         else
558                 resv = &bo->base._resv;
559
560         if (dma_resv_test_signaled_rcu(resv, true))
561                 ret = 0;
562         else
563                 ret = -EBUSY;
564
565         if (ret && !no_wait_gpu) {
566                 long lret;
567
568                 if (unlock_resv)
569                         dma_resv_unlock(bo->base.resv);
570                 spin_unlock(&glob->lru_lock);
571
572                 lret = dma_resv_wait_timeout_rcu(resv, true,
573                                                            interruptible,
574                                                            30 * HZ);
575
576                 if (lret < 0)
577                         return lret;
578                 else if (lret == 0)
579                         return -EBUSY;
580
581                 spin_lock(&glob->lru_lock);
582                 if (unlock_resv && !dma_resv_trylock(bo->base.resv)) {
583                         /*
584                          * We raced, and lost, someone else holds the reservation now,
585                          * and is probably busy in ttm_bo_cleanup_memtype_use.
586                          *
587                          * Even if it's not the case, because we finished waiting any
588                          * delayed destruction would succeed, so just return success
589                          * here.
590                          */
591                         spin_unlock(&glob->lru_lock);
592                         return 0;
593                 }
594                 ret = 0;
595         }
596
597         if (ret || unlikely(list_empty(&bo->ddestroy))) {
598                 if (unlock_resv)
599                         dma_resv_unlock(bo->base.resv);
600                 spin_unlock(&glob->lru_lock);
601                 return ret;
602         }
603
604         ttm_bo_del_from_lru(bo);
605         list_del_init(&bo->ddestroy);
606         kref_put(&bo->list_kref, ttm_bo_ref_bug);
607
608         spin_unlock(&glob->lru_lock);
609         ttm_bo_cleanup_memtype_use(bo);
610
611         if (unlock_resv)
612                 dma_resv_unlock(bo->base.resv);
613
614         return 0;
615 }
616
617 /**
618  * Traverse the delayed list, and call ttm_bo_cleanup_refs on all
619  * encountered buffers.
620  */
621 static bool ttm_bo_delayed_delete(struct ttm_bo_device *bdev, bool remove_all)
622 {
623         struct ttm_bo_global *glob = bdev->glob;
624         struct list_head removed;
625         bool empty;
626
627         INIT_LIST_HEAD(&removed);
628
629         spin_lock(&glob->lru_lock);
630         while (!list_empty(&bdev->ddestroy)) {
631                 struct ttm_buffer_object *bo;
632
633                 bo = list_first_entry(&bdev->ddestroy, struct ttm_buffer_object,
634                                       ddestroy);
635                 kref_get(&bo->list_kref);
636                 list_move_tail(&bo->ddestroy, &removed);
637
638                 if (remove_all || bo->base.resv != &bo->base._resv) {
639                         spin_unlock(&glob->lru_lock);
640                         dma_resv_lock(bo->base.resv, NULL);
641
642                         spin_lock(&glob->lru_lock);
643                         ttm_bo_cleanup_refs(bo, false, !remove_all, true);
644
645                 } else if (dma_resv_trylock(bo->base.resv)) {
646                         ttm_bo_cleanup_refs(bo, false, !remove_all, true);
647                 } else {
648                         spin_unlock(&glob->lru_lock);
649                 }
650
651                 kref_put(&bo->list_kref, ttm_bo_release_list);
652                 spin_lock(&glob->lru_lock);
653         }
654         list_splice_tail(&removed, &bdev->ddestroy);
655         empty = list_empty(&bdev->ddestroy);
656         spin_unlock(&glob->lru_lock);
657
658         return empty;
659 }
660
661 static void ttm_bo_delayed_workqueue(struct work_struct *work)
662 {
663         struct ttm_bo_device *bdev =
664             container_of(work, struct ttm_bo_device, wq.work);
665
666         if (!ttm_bo_delayed_delete(bdev, false))
667                 schedule_delayed_work(&bdev->wq,
668                                       ((HZ / 100) < 1) ? 1 : HZ / 100);
669 }
670
671 static void ttm_bo_release(struct kref *kref)
672 {
673         struct ttm_buffer_object *bo =
674             container_of(kref, struct ttm_buffer_object, kref);
675         struct ttm_bo_device *bdev = bo->bdev;
676         struct ttm_mem_type_manager *man = &bdev->man[bo->mem.mem_type];
677
678         if (bo->bdev->driver->release_notify)
679                 bo->bdev->driver->release_notify(bo);
680
681         drm_vma_offset_remove(&bdev->vma_manager, &bo->base.vma_node);
682         ttm_mem_io_lock(man, false);
683         ttm_mem_io_free_vm(bo);
684         ttm_mem_io_unlock(man);
685         ttm_bo_cleanup_refs_or_queue(bo);
686         kref_put(&bo->list_kref, ttm_bo_release_list);
687 }
688
689 void ttm_bo_put(struct ttm_buffer_object *bo)
690 {
691         kref_put(&bo->kref, ttm_bo_release);
692 }
693 EXPORT_SYMBOL(ttm_bo_put);
694
695 int ttm_bo_lock_delayed_workqueue(struct ttm_bo_device *bdev)
696 {
697         return cancel_delayed_work_sync(&bdev->wq);
698 }
699 EXPORT_SYMBOL(ttm_bo_lock_delayed_workqueue);
700
701 void ttm_bo_unlock_delayed_workqueue(struct ttm_bo_device *bdev, int resched)
702 {
703         if (resched)
704                 schedule_delayed_work(&bdev->wq,
705                                       ((HZ / 100) < 1) ? 1 : HZ / 100);
706 }
707 EXPORT_SYMBOL(ttm_bo_unlock_delayed_workqueue);
708
709 static int ttm_bo_evict(struct ttm_buffer_object *bo,
710                         struct ttm_operation_ctx *ctx)
711 {
712         struct ttm_bo_device *bdev = bo->bdev;
713         struct ttm_mem_reg evict_mem;
714         struct ttm_placement placement;
715         int ret = 0;
716
717         dma_resv_assert_held(bo->base.resv);
718
719         placement.num_placement = 0;
720         placement.num_busy_placement = 0;
721         bdev->driver->evict_flags(bo, &placement);
722
723         if (!placement.num_placement && !placement.num_busy_placement) {
724                 ret = ttm_bo_pipeline_gutting(bo);
725                 if (ret)
726                         return ret;
727
728                 return ttm_tt_create(bo, false);
729         }
730
731         evict_mem = bo->mem;
732         evict_mem.mm_node = NULL;
733         evict_mem.bus.io_reserved_vm = false;
734         evict_mem.bus.io_reserved_count = 0;
735
736         ret = ttm_bo_mem_space(bo, &placement, &evict_mem, ctx);
737         if (ret) {
738                 if (ret != -ERESTARTSYS) {
739                         pr_err("Failed to find memory space for buffer 0x%p eviction\n",
740                                bo);
741                         ttm_bo_mem_space_debug(bo, &placement);
742                 }
743                 goto out;
744         }
745
746         ret = ttm_bo_handle_move_mem(bo, &evict_mem, true, ctx);
747         if (unlikely(ret)) {
748                 if (ret != -ERESTARTSYS)
749                         pr_err("Buffer eviction failed\n");
750                 ttm_bo_mem_put(bo, &evict_mem);
751                 goto out;
752         }
753         bo->evicted = true;
754 out:
755         return ret;
756 }
757
758 bool ttm_bo_eviction_valuable(struct ttm_buffer_object *bo,
759                               const struct ttm_place *place)
760 {
761         /* Don't evict this BO if it's outside of the
762          * requested placement range
763          */
764         if (place->fpfn >= (bo->mem.start + bo->mem.size) ||
765             (place->lpfn && place->lpfn <= bo->mem.start))
766                 return false;
767
768         return true;
769 }
770 EXPORT_SYMBOL(ttm_bo_eviction_valuable);
771
772 /**
773  * Check the target bo is allowable to be evicted or swapout, including cases:
774  *
775  * a. if share same reservation object with ctx->resv, have assumption
776  * reservation objects should already be locked, so not lock again and
777  * return true directly when either the opreation allow_reserved_eviction
778  * or the target bo already is in delayed free list;
779  *
780  * b. Otherwise, trylock it.
781  */
782 static bool ttm_bo_evict_swapout_allowable(struct ttm_buffer_object *bo,
783                         struct ttm_operation_ctx *ctx, bool *locked, bool *busy)
784 {
785         bool ret = false;
786
787         if (bo->base.resv == ctx->resv) {
788                 dma_resv_assert_held(bo->base.resv);
789                 if (ctx->flags & TTM_OPT_FLAG_ALLOW_RES_EVICT
790                     || !list_empty(&bo->ddestroy))
791                         ret = true;
792                 *locked = false;
793                 if (busy)
794                         *busy = false;
795         } else {
796                 ret = dma_resv_trylock(bo->base.resv);
797                 *locked = ret;
798                 if (busy)
799                         *busy = !ret;
800         }
801
802         return ret;
803 }
804
805 /**
806  * ttm_mem_evict_wait_busy - wait for a busy BO to become available
807  *
808  * @busy_bo: BO which couldn't be locked with trylock
809  * @ctx: operation context
810  * @ticket: acquire ticket
811  *
812  * Try to lock a busy buffer object to avoid failing eviction.
813  */
814 static int ttm_mem_evict_wait_busy(struct ttm_buffer_object *busy_bo,
815                                    struct ttm_operation_ctx *ctx,
816                                    struct ww_acquire_ctx *ticket)
817 {
818         int r;
819
820         if (!busy_bo || !ticket)
821                 return -EBUSY;
822
823         if (ctx->interruptible)
824                 r = dma_resv_lock_interruptible(busy_bo->base.resv,
825                                                           ticket);
826         else
827                 r = dma_resv_lock(busy_bo->base.resv, ticket);
828
829         /*
830          * TODO: It would be better to keep the BO locked until allocation is at
831          * least tried one more time, but that would mean a much larger rework
832          * of TTM.
833          */
834         if (!r)
835                 dma_resv_unlock(busy_bo->base.resv);
836
837         return r == -EDEADLK ? -EBUSY : r;
838 }
839
840 static int ttm_mem_evict_first(struct ttm_bo_device *bdev,
841                                uint32_t mem_type,
842                                const struct ttm_place *place,
843                                struct ttm_operation_ctx *ctx,
844                                struct ww_acquire_ctx *ticket)
845 {
846         struct ttm_buffer_object *bo = NULL, *busy_bo = NULL;
847         struct ttm_bo_global *glob = bdev->glob;
848         struct ttm_mem_type_manager *man = &bdev->man[mem_type];
849         bool locked = false;
850         unsigned i;
851         int ret;
852
853         spin_lock(&glob->lru_lock);
854         for (i = 0; i < TTM_MAX_BO_PRIORITY; ++i) {
855                 list_for_each_entry(bo, &man->lru[i], lru) {
856                         bool busy;
857
858                         if (!ttm_bo_evict_swapout_allowable(bo, ctx, &locked,
859                                                             &busy)) {
860                                 if (busy && !busy_bo && ticket !=
861                                     dma_resv_locking_ctx(bo->base.resv))
862                                         busy_bo = bo;
863                                 continue;
864                         }
865
866                         if (place && !bdev->driver->eviction_valuable(bo,
867                                                                       place)) {
868                                 if (locked)
869                                         dma_resv_unlock(bo->base.resv);
870                                 continue;
871                         }
872                         break;
873                 }
874
875                 /* If the inner loop terminated early, we have our candidate */
876                 if (&bo->lru != &man->lru[i])
877                         break;
878
879                 bo = NULL;
880         }
881
882         if (!bo) {
883                 if (busy_bo)
884                         kref_get(&busy_bo->list_kref);
885                 spin_unlock(&glob->lru_lock);
886                 ret = ttm_mem_evict_wait_busy(busy_bo, ctx, ticket);
887                 if (busy_bo)
888                         kref_put(&busy_bo->list_kref, ttm_bo_release_list);
889                 return ret;
890         }
891
892         kref_get(&bo->list_kref);
893
894         if (!list_empty(&bo->ddestroy)) {
895                 ret = ttm_bo_cleanup_refs(bo, ctx->interruptible,
896                                           ctx->no_wait_gpu, locked);
897                 kref_put(&bo->list_kref, ttm_bo_release_list);
898                 return ret;
899         }
900
901         ttm_bo_del_from_lru(bo);
902         spin_unlock(&glob->lru_lock);
903
904         ret = ttm_bo_evict(bo, ctx);
905         if (locked) {
906                 ttm_bo_unreserve(bo);
907         } else {
908                 spin_lock(&glob->lru_lock);
909                 ttm_bo_add_to_lru(bo);
910                 spin_unlock(&glob->lru_lock);
911         }
912
913         kref_put(&bo->list_kref, ttm_bo_release_list);
914         return ret;
915 }
916
917 void ttm_bo_mem_put(struct ttm_buffer_object *bo, struct ttm_mem_reg *mem)
918 {
919         struct ttm_mem_type_manager *man = &bo->bdev->man[mem->mem_type];
920
921         if (mem->mm_node)
922                 (*man->func->put_node)(man, mem);
923 }
924 EXPORT_SYMBOL(ttm_bo_mem_put);
925
926 /**
927  * Add the last move fence to the BO and reserve a new shared slot.
928  */
929 static int ttm_bo_add_move_fence(struct ttm_buffer_object *bo,
930                                  struct ttm_mem_type_manager *man,
931                                  struct ttm_mem_reg *mem,
932                                  bool no_wait_gpu)
933 {
934         struct dma_fence *fence;
935         int ret;
936
937         spin_lock(&man->move_lock);
938         fence = dma_fence_get(man->move);
939         spin_unlock(&man->move_lock);
940
941         if (!fence)
942                 return 0;
943
944         if (no_wait_gpu)
945                 return -EBUSY;
946
947         dma_resv_add_shared_fence(bo->base.resv, fence);
948
949         ret = dma_resv_reserve_shared(bo->base.resv, 1);
950         if (unlikely(ret)) {
951                 dma_fence_put(fence);
952                 return ret;
953         }
954
955         dma_fence_put(bo->moving);
956         bo->moving = fence;
957         return 0;
958 }
959
960 /**
961  * Repeatedly evict memory from the LRU for @mem_type until we create enough
962  * space, or we've evicted everything and there isn't enough space.
963  */
964 static int ttm_bo_mem_force_space(struct ttm_buffer_object *bo,
965                                   const struct ttm_place *place,
966                                   struct ttm_mem_reg *mem,
967                                   struct ttm_operation_ctx *ctx)
968 {
969         struct ttm_bo_device *bdev = bo->bdev;
970         struct ttm_mem_type_manager *man = &bdev->man[mem->mem_type];
971         struct ww_acquire_ctx *ticket;
972         int ret;
973
974         ticket = dma_resv_locking_ctx(bo->base.resv);
975         do {
976                 ret = (*man->func->get_node)(man, bo, place, mem);
977                 if (unlikely(ret != 0))
978                         return ret;
979                 if (mem->mm_node)
980                         break;
981                 ret = ttm_mem_evict_first(bdev, mem->mem_type, place, ctx,
982                                           ticket);
983                 if (unlikely(ret != 0))
984                         return ret;
985         } while (1);
986
987         return ttm_bo_add_move_fence(bo, man, mem, ctx->no_wait_gpu);
988 }
989
990 static uint32_t ttm_bo_select_caching(struct ttm_mem_type_manager *man,
991                                       uint32_t cur_placement,
992                                       uint32_t proposed_placement)
993 {
994         uint32_t caching = proposed_placement & TTM_PL_MASK_CACHING;
995         uint32_t result = proposed_placement & ~TTM_PL_MASK_CACHING;
996
997         /**
998          * Keep current caching if possible.
999          */
1000
1001         if ((cur_placement & caching) != 0)
1002                 result |= (cur_placement & caching);
1003         else if ((man->default_caching & caching) != 0)
1004                 result |= man->default_caching;
1005         else if ((TTM_PL_FLAG_CACHED & caching) != 0)
1006                 result |= TTM_PL_FLAG_CACHED;
1007         else if ((TTM_PL_FLAG_WC & caching) != 0)
1008                 result |= TTM_PL_FLAG_WC;
1009         else if ((TTM_PL_FLAG_UNCACHED & caching) != 0)
1010                 result |= TTM_PL_FLAG_UNCACHED;
1011
1012         return result;
1013 }
1014
1015 static bool ttm_bo_mt_compatible(struct ttm_mem_type_manager *man,
1016                                  uint32_t mem_type,
1017                                  const struct ttm_place *place,
1018                                  uint32_t *masked_placement)
1019 {
1020         uint32_t cur_flags = ttm_bo_type_flags(mem_type);
1021
1022         if ((cur_flags & place->flags & TTM_PL_MASK_MEM) == 0)
1023                 return false;
1024
1025         if ((place->flags & man->available_caching) == 0)
1026                 return false;
1027
1028         cur_flags |= (place->flags & man->available_caching);
1029
1030         *masked_placement = cur_flags;
1031         return true;
1032 }
1033
1034 /**
1035  * ttm_bo_mem_placement - check if placement is compatible
1036  * @bo: BO to find memory for
1037  * @place: where to search
1038  * @mem: the memory object to fill in
1039  * @ctx: operation context
1040  *
1041  * Check if placement is compatible and fill in mem structure.
1042  * Returns -EBUSY if placement won't work or negative error code.
1043  * 0 when placement can be used.
1044  */
1045 static int ttm_bo_mem_placement(struct ttm_buffer_object *bo,
1046                                 const struct ttm_place *place,
1047                                 struct ttm_mem_reg *mem,
1048                                 struct ttm_operation_ctx *ctx)
1049 {
1050         struct ttm_bo_device *bdev = bo->bdev;
1051         uint32_t mem_type = TTM_PL_SYSTEM;
1052         struct ttm_mem_type_manager *man;
1053         uint32_t cur_flags = 0;
1054         int ret;
1055
1056         ret = ttm_mem_type_from_place(place, &mem_type);
1057         if (ret)
1058                 return ret;
1059
1060         man = &bdev->man[mem_type];
1061         if (!man->has_type || !man->use_type)
1062                 return -EBUSY;
1063
1064         if (!ttm_bo_mt_compatible(man, mem_type, place, &cur_flags))
1065                 return -EBUSY;
1066
1067         cur_flags = ttm_bo_select_caching(man, bo->mem.placement, cur_flags);
1068         /*
1069          * Use the access and other non-mapping-related flag bits from
1070          * the memory placement flags to the current flags
1071          */
1072         ttm_flag_masked(&cur_flags, place->flags, ~TTM_PL_MASK_MEMTYPE);
1073
1074         mem->mem_type = mem_type;
1075         mem->placement = cur_flags;
1076
1077         if (bo->mem.mem_type < mem_type && !list_empty(&bo->lru)) {
1078                 spin_lock(&bo->bdev->glob->lru_lock);
1079                 ttm_bo_del_from_lru(bo);
1080                 ttm_bo_add_mem_to_lru(bo, mem);
1081                 spin_unlock(&bo->bdev->glob->lru_lock);
1082         }
1083
1084         return 0;
1085 }
1086
1087 /**
1088  * Creates space for memory region @mem according to its type.
1089  *
1090  * This function first searches for free space in compatible memory types in
1091  * the priority order defined by the driver.  If free space isn't found, then
1092  * ttm_bo_mem_force_space is attempted in priority order to evict and find
1093  * space.
1094  */
1095 int ttm_bo_mem_space(struct ttm_buffer_object *bo,
1096                         struct ttm_placement *placement,
1097                         struct ttm_mem_reg *mem,
1098                         struct ttm_operation_ctx *ctx)
1099 {
1100         struct ttm_bo_device *bdev = bo->bdev;
1101         bool type_found = false;
1102         int i, ret;
1103
1104         ret = dma_resv_reserve_shared(bo->base.resv, 1);
1105         if (unlikely(ret))
1106                 return ret;
1107
1108         mem->mm_node = NULL;
1109         for (i = 0; i < placement->num_placement; ++i) {
1110                 const struct ttm_place *place = &placement->placement[i];
1111                 struct ttm_mem_type_manager *man;
1112
1113                 ret = ttm_bo_mem_placement(bo, place, mem, ctx);
1114                 if (ret == -EBUSY)
1115                         continue;
1116                 if (ret)
1117                         goto error;
1118
1119                 type_found = true;
1120                 mem->mm_node = NULL;
1121                 if (mem->mem_type == TTM_PL_SYSTEM)
1122                         return 0;
1123
1124                 man = &bdev->man[mem->mem_type];
1125                 ret = (*man->func->get_node)(man, bo, place, mem);
1126                 if (unlikely(ret))
1127                         goto error;
1128
1129                 if (!mem->mm_node)
1130                         continue;
1131
1132                 ret = ttm_bo_add_move_fence(bo, man, mem, ctx->no_wait_gpu);
1133                 if (unlikely(ret)) {
1134                         (*man->func->put_node)(man, mem);
1135                         if (ret == -EBUSY)
1136                                 continue;
1137
1138                         goto error;
1139                 }
1140                 return 0;
1141         }
1142
1143         for (i = 0; i < placement->num_busy_placement; ++i) {
1144                 const struct ttm_place *place = &placement->busy_placement[i];
1145
1146                 ret = ttm_bo_mem_placement(bo, place, mem, ctx);
1147                 if (ret == -EBUSY)
1148                         continue;
1149                 if (ret)
1150                         goto error;
1151
1152                 type_found = true;
1153                 mem->mm_node = NULL;
1154                 if (mem->mem_type == TTM_PL_SYSTEM)
1155                         return 0;
1156
1157                 ret = ttm_bo_mem_force_space(bo, place, mem, ctx);
1158                 if (ret == 0 && mem->mm_node)
1159                         return 0;
1160
1161                 if (ret && ret != -EBUSY)
1162                         goto error;
1163         }
1164
1165         ret = -ENOMEM;
1166         if (!type_found) {
1167                 pr_err(TTM_PFX "No compatible memory type found\n");
1168                 ret = -EINVAL;
1169         }
1170
1171 error:
1172         if (bo->mem.mem_type == TTM_PL_SYSTEM && !list_empty(&bo->lru)) {
1173                 spin_lock(&bo->bdev->glob->lru_lock);
1174                 ttm_bo_move_to_lru_tail(bo, NULL);
1175                 spin_unlock(&bo->bdev->glob->lru_lock);
1176         }
1177
1178         return ret;
1179 }
1180 EXPORT_SYMBOL(ttm_bo_mem_space);
1181
1182 static int ttm_bo_move_buffer(struct ttm_buffer_object *bo,
1183                               struct ttm_placement *placement,
1184                               struct ttm_operation_ctx *ctx)
1185 {
1186         int ret = 0;
1187         struct ttm_mem_reg mem;
1188
1189         dma_resv_assert_held(bo->base.resv);
1190
1191         mem.num_pages = bo->num_pages;
1192         mem.size = mem.num_pages << PAGE_SHIFT;
1193         mem.page_alignment = bo->mem.page_alignment;
1194         mem.bus.io_reserved_vm = false;
1195         mem.bus.io_reserved_count = 0;
1196         /*
1197          * Determine where to move the buffer.
1198          */
1199         ret = ttm_bo_mem_space(bo, placement, &mem, ctx);
1200         if (ret)
1201                 goto out_unlock;
1202         ret = ttm_bo_handle_move_mem(bo, &mem, false, ctx);
1203 out_unlock:
1204         if (ret && mem.mm_node)
1205                 ttm_bo_mem_put(bo, &mem);
1206         return ret;
1207 }
1208
1209 static bool ttm_bo_places_compat(const struct ttm_place *places,
1210                                  unsigned num_placement,
1211                                  struct ttm_mem_reg *mem,
1212                                  uint32_t *new_flags)
1213 {
1214         unsigned i;
1215
1216         for (i = 0; i < num_placement; i++) {
1217                 const struct ttm_place *heap = &places[i];
1218
1219                 if (mem->mm_node && (mem->start < heap->fpfn ||
1220                      (heap->lpfn != 0 && (mem->start + mem->num_pages) > heap->lpfn)))
1221                         continue;
1222
1223                 *new_flags = heap->flags;
1224                 if ((*new_flags & mem->placement & TTM_PL_MASK_CACHING) &&
1225                     (*new_flags & mem->placement & TTM_PL_MASK_MEM) &&
1226                     (!(*new_flags & TTM_PL_FLAG_CONTIGUOUS) ||
1227                      (mem->placement & TTM_PL_FLAG_CONTIGUOUS)))
1228                         return true;
1229         }
1230         return false;
1231 }
1232
1233 bool ttm_bo_mem_compat(struct ttm_placement *placement,
1234                        struct ttm_mem_reg *mem,
1235                        uint32_t *new_flags)
1236 {
1237         if (ttm_bo_places_compat(placement->placement, placement->num_placement,
1238                                  mem, new_flags))
1239                 return true;
1240
1241         if ((placement->busy_placement != placement->placement ||
1242              placement->num_busy_placement > placement->num_placement) &&
1243             ttm_bo_places_compat(placement->busy_placement,
1244                                  placement->num_busy_placement,
1245                                  mem, new_flags))
1246                 return true;
1247
1248         return false;
1249 }
1250 EXPORT_SYMBOL(ttm_bo_mem_compat);
1251
1252 int ttm_bo_validate(struct ttm_buffer_object *bo,
1253                     struct ttm_placement *placement,
1254                     struct ttm_operation_ctx *ctx)
1255 {
1256         int ret;
1257         uint32_t new_flags;
1258
1259         dma_resv_assert_held(bo->base.resv);
1260         /*
1261          * Check whether we need to move buffer.
1262          */
1263         if (!ttm_bo_mem_compat(placement, &bo->mem, &new_flags)) {
1264                 ret = ttm_bo_move_buffer(bo, placement, ctx);
1265                 if (ret)
1266                         return ret;
1267         } else {
1268                 /*
1269                  * Use the access and other non-mapping-related flag bits from
1270                  * the compatible memory placement flags to the active flags
1271                  */
1272                 ttm_flag_masked(&bo->mem.placement, new_flags,
1273                                 ~TTM_PL_MASK_MEMTYPE);
1274         }
1275         /*
1276          * We might need to add a TTM.
1277          */
1278         if (bo->mem.mem_type == TTM_PL_SYSTEM && bo->ttm == NULL) {
1279                 ret = ttm_tt_create(bo, true);
1280                 if (ret)
1281                         return ret;
1282         }
1283         return 0;
1284 }
1285 EXPORT_SYMBOL(ttm_bo_validate);
1286
1287 int ttm_bo_init_reserved(struct ttm_bo_device *bdev,
1288                          struct ttm_buffer_object *bo,
1289                          unsigned long size,
1290                          enum ttm_bo_type type,
1291                          struct ttm_placement *placement,
1292                          uint32_t page_alignment,
1293                          struct ttm_operation_ctx *ctx,
1294                          size_t acc_size,
1295                          struct sg_table *sg,
1296                          struct dma_resv *resv,
1297                          void (*destroy) (struct ttm_buffer_object *))
1298 {
1299         int ret = 0;
1300         unsigned long num_pages;
1301         struct ttm_mem_global *mem_glob = bdev->glob->mem_glob;
1302         bool locked;
1303
1304         ret = ttm_mem_global_alloc(mem_glob, acc_size, ctx);
1305         if (ret) {
1306                 pr_err("Out of kernel memory\n");
1307                 if (destroy)
1308                         (*destroy)(bo);
1309                 else
1310                         kfree(bo);
1311                 return -ENOMEM;
1312         }
1313
1314         num_pages = (size + PAGE_SIZE - 1) >> PAGE_SHIFT;
1315         if (num_pages == 0) {
1316                 pr_err("Illegal buffer object size\n");
1317                 if (destroy)
1318                         (*destroy)(bo);
1319                 else
1320                         kfree(bo);
1321                 ttm_mem_global_free(mem_glob, acc_size);
1322                 return -EINVAL;
1323         }
1324         bo->destroy = destroy ? destroy : ttm_bo_default_destroy;
1325
1326         kref_init(&bo->kref);
1327         kref_init(&bo->list_kref);
1328         atomic_set(&bo->cpu_writers, 0);
1329         INIT_LIST_HEAD(&bo->lru);
1330         INIT_LIST_HEAD(&bo->ddestroy);
1331         INIT_LIST_HEAD(&bo->swap);
1332         INIT_LIST_HEAD(&bo->io_reserve_lru);
1333         mutex_init(&bo->wu_mutex);
1334         bo->bdev = bdev;
1335         bo->type = type;
1336         bo->num_pages = num_pages;
1337         bo->mem.size = num_pages << PAGE_SHIFT;
1338         bo->mem.mem_type = TTM_PL_SYSTEM;
1339         bo->mem.num_pages = bo->num_pages;
1340         bo->mem.mm_node = NULL;
1341         bo->mem.page_alignment = page_alignment;
1342         bo->mem.bus.io_reserved_vm = false;
1343         bo->mem.bus.io_reserved_count = 0;
1344         bo->moving = NULL;
1345         bo->mem.placement = (TTM_PL_FLAG_SYSTEM | TTM_PL_FLAG_CACHED);
1346         bo->acc_size = acc_size;
1347         bo->sg = sg;
1348         if (resv) {
1349                 bo->base.resv = resv;
1350                 dma_resv_assert_held(bo->base.resv);
1351         } else {
1352                 bo->base.resv = &bo->base._resv;
1353         }
1354         if (!ttm_bo_uses_embedded_gem_object(bo)) {
1355                 /*
1356                  * bo.gem is not initialized, so we have to setup the
1357                  * struct elements we want use regardless.
1358                  */
1359                 dma_resv_init(&bo->base._resv);
1360                 drm_vma_node_reset(&bo->base.vma_node);
1361         }
1362         atomic_inc(&bo->bdev->glob->bo_count);
1363
1364         /*
1365          * For ttm_bo_type_device buffers, allocate
1366          * address space from the device.
1367          */
1368         if (bo->type == ttm_bo_type_device ||
1369             bo->type == ttm_bo_type_sg)
1370                 ret = drm_vma_offset_add(&bdev->vma_manager, &bo->base.vma_node,
1371                                          bo->mem.num_pages);
1372
1373         /* passed reservation objects should already be locked,
1374          * since otherwise lockdep will be angered in radeon.
1375          */
1376         if (!resv) {
1377                 locked = dma_resv_trylock(bo->base.resv);
1378                 WARN_ON(!locked);
1379         }
1380
1381         if (likely(!ret))
1382                 ret = ttm_bo_validate(bo, placement, ctx);
1383
1384         if (unlikely(ret)) {
1385                 if (!resv)
1386                         ttm_bo_unreserve(bo);
1387
1388                 ttm_bo_put(bo);
1389                 return ret;
1390         }
1391
1392         if (resv && !(bo->mem.placement & TTM_PL_FLAG_NO_EVICT)) {
1393                 spin_lock(&bdev->glob->lru_lock);
1394                 ttm_bo_add_to_lru(bo);
1395                 spin_unlock(&bdev->glob->lru_lock);
1396         }
1397
1398         return ret;
1399 }
1400 EXPORT_SYMBOL(ttm_bo_init_reserved);
1401
1402 int ttm_bo_init(struct ttm_bo_device *bdev,
1403                 struct ttm_buffer_object *bo,
1404                 unsigned long size,
1405                 enum ttm_bo_type type,
1406                 struct ttm_placement *placement,
1407                 uint32_t page_alignment,
1408                 bool interruptible,
1409                 size_t acc_size,
1410                 struct sg_table *sg,
1411                 struct dma_resv *resv,
1412                 void (*destroy) (struct ttm_buffer_object *))
1413 {
1414         struct ttm_operation_ctx ctx = { interruptible, false };
1415         int ret;
1416
1417         ret = ttm_bo_init_reserved(bdev, bo, size, type, placement,
1418                                    page_alignment, &ctx, acc_size,
1419                                    sg, resv, destroy);
1420         if (ret)
1421                 return ret;
1422
1423         if (!resv)
1424                 ttm_bo_unreserve(bo);
1425
1426         return 0;
1427 }
1428 EXPORT_SYMBOL(ttm_bo_init);
1429
1430 size_t ttm_bo_acc_size(struct ttm_bo_device *bdev,
1431                        unsigned long bo_size,
1432                        unsigned struct_size)
1433 {
1434         unsigned npages = (PAGE_ALIGN(bo_size)) >> PAGE_SHIFT;
1435         size_t size = 0;
1436
1437         size += ttm_round_pot(struct_size);
1438         size += ttm_round_pot(npages * sizeof(void *));
1439         size += ttm_round_pot(sizeof(struct ttm_tt));
1440         return size;
1441 }
1442 EXPORT_SYMBOL(ttm_bo_acc_size);
1443
1444 size_t ttm_bo_dma_acc_size(struct ttm_bo_device *bdev,
1445                            unsigned long bo_size,
1446                            unsigned struct_size)
1447 {
1448         unsigned npages = (PAGE_ALIGN(bo_size)) >> PAGE_SHIFT;
1449         size_t size = 0;
1450
1451         size += ttm_round_pot(struct_size);
1452         size += ttm_round_pot(npages * (2*sizeof(void *) + sizeof(dma_addr_t)));
1453         size += ttm_round_pot(sizeof(struct ttm_dma_tt));
1454         return size;
1455 }
1456 EXPORT_SYMBOL(ttm_bo_dma_acc_size);
1457
1458 int ttm_bo_create(struct ttm_bo_device *bdev,
1459                         unsigned long size,
1460                         enum ttm_bo_type type,
1461                         struct ttm_placement *placement,
1462                         uint32_t page_alignment,
1463                         bool interruptible,
1464                         struct ttm_buffer_object **p_bo)
1465 {
1466         struct ttm_buffer_object *bo;
1467         size_t acc_size;
1468         int ret;
1469
1470         bo = kzalloc(sizeof(*bo), GFP_KERNEL);
1471         if (unlikely(bo == NULL))
1472                 return -ENOMEM;
1473
1474         acc_size = ttm_bo_acc_size(bdev, size, sizeof(struct ttm_buffer_object));
1475         ret = ttm_bo_init(bdev, bo, size, type, placement, page_alignment,
1476                           interruptible, acc_size,
1477                           NULL, NULL, NULL);
1478         if (likely(ret == 0))
1479                 *p_bo = bo;
1480
1481         return ret;
1482 }
1483 EXPORT_SYMBOL(ttm_bo_create);
1484
1485 static int ttm_bo_force_list_clean(struct ttm_bo_device *bdev,
1486                                    unsigned mem_type)
1487 {
1488         struct ttm_operation_ctx ctx = {
1489                 .interruptible = false,
1490                 .no_wait_gpu = false,
1491                 .flags = TTM_OPT_FLAG_FORCE_ALLOC
1492         };
1493         struct ttm_mem_type_manager *man = &bdev->man[mem_type];
1494         struct ttm_bo_global *glob = bdev->glob;
1495         struct dma_fence *fence;
1496         int ret;
1497         unsigned i;
1498
1499         /*
1500          * Can't use standard list traversal since we're unlocking.
1501          */
1502
1503         spin_lock(&glob->lru_lock);
1504         for (i = 0; i < TTM_MAX_BO_PRIORITY; ++i) {
1505                 while (!list_empty(&man->lru[i])) {
1506                         spin_unlock(&glob->lru_lock);
1507                         ret = ttm_mem_evict_first(bdev, mem_type, NULL, &ctx,
1508                                                   NULL);
1509                         if (ret)
1510                                 return ret;
1511                         spin_lock(&glob->lru_lock);
1512                 }
1513         }
1514         spin_unlock(&glob->lru_lock);
1515
1516         spin_lock(&man->move_lock);
1517         fence = dma_fence_get(man->move);
1518         spin_unlock(&man->move_lock);
1519
1520         if (fence) {
1521                 ret = dma_fence_wait(fence, false);
1522                 dma_fence_put(fence);
1523                 if (ret)
1524                         return ret;
1525         }
1526
1527         return 0;
1528 }
1529
1530 int ttm_bo_clean_mm(struct ttm_bo_device *bdev, unsigned mem_type)
1531 {
1532         struct ttm_mem_type_manager *man;
1533         int ret = -EINVAL;
1534
1535         if (mem_type >= TTM_NUM_MEM_TYPES) {
1536                 pr_err("Illegal memory type %d\n", mem_type);
1537                 return ret;
1538         }
1539         man = &bdev->man[mem_type];
1540
1541         if (!man->has_type) {
1542                 pr_err("Trying to take down uninitialized memory manager type %u\n",
1543                        mem_type);
1544                 return ret;
1545         }
1546
1547         man->use_type = false;
1548         man->has_type = false;
1549
1550         ret = 0;
1551         if (mem_type > 0) {
1552                 ret = ttm_bo_force_list_clean(bdev, mem_type);
1553                 if (ret) {
1554                         pr_err("Cleanup eviction failed\n");
1555                         return ret;
1556                 }
1557
1558                 ret = (*man->func->takedown)(man);
1559         }
1560
1561         dma_fence_put(man->move);
1562         man->move = NULL;
1563
1564         return ret;
1565 }
1566 EXPORT_SYMBOL(ttm_bo_clean_mm);
1567
1568 int ttm_bo_evict_mm(struct ttm_bo_device *bdev, unsigned mem_type)
1569 {
1570         struct ttm_mem_type_manager *man = &bdev->man[mem_type];
1571
1572         if (mem_type == 0 || mem_type >= TTM_NUM_MEM_TYPES) {
1573                 pr_err("Illegal memory manager memory type %u\n", mem_type);
1574                 return -EINVAL;
1575         }
1576
1577         if (!man->has_type) {
1578                 pr_err("Memory type %u has not been initialized\n", mem_type);
1579                 return 0;
1580         }
1581
1582         return ttm_bo_force_list_clean(bdev, mem_type);
1583 }
1584 EXPORT_SYMBOL(ttm_bo_evict_mm);
1585
1586 int ttm_bo_init_mm(struct ttm_bo_device *bdev, unsigned type,
1587                         unsigned long p_size)
1588 {
1589         int ret;
1590         struct ttm_mem_type_manager *man;
1591         unsigned i;
1592
1593         BUG_ON(type >= TTM_NUM_MEM_TYPES);
1594         man = &bdev->man[type];
1595         BUG_ON(man->has_type);
1596         man->io_reserve_fastpath = true;
1597         man->use_io_reserve_lru = false;
1598         mutex_init(&man->io_reserve_mutex);
1599         spin_lock_init(&man->move_lock);
1600         INIT_LIST_HEAD(&man->io_reserve_lru);
1601
1602         ret = bdev->driver->init_mem_type(bdev, type, man);
1603         if (ret)
1604                 return ret;
1605         man->bdev = bdev;
1606
1607         if (type != TTM_PL_SYSTEM) {
1608                 ret = (*man->func->init)(man, p_size);
1609                 if (ret)
1610                         return ret;
1611         }
1612         man->has_type = true;
1613         man->use_type = true;
1614         man->size = p_size;
1615
1616         for (i = 0; i < TTM_MAX_BO_PRIORITY; ++i)
1617                 INIT_LIST_HEAD(&man->lru[i]);
1618         man->move = NULL;
1619
1620         return 0;
1621 }
1622 EXPORT_SYMBOL(ttm_bo_init_mm);
1623
1624 static void ttm_bo_global_kobj_release(struct kobject *kobj)
1625 {
1626         struct ttm_bo_global *glob =
1627                 container_of(kobj, struct ttm_bo_global, kobj);
1628
1629         __free_page(glob->dummy_read_page);
1630 }
1631
1632 static void ttm_bo_global_release(void)
1633 {
1634         struct ttm_bo_global *glob = &ttm_bo_glob;
1635
1636         mutex_lock(&ttm_global_mutex);
1637         if (--ttm_bo_glob_use_count > 0)
1638                 goto out;
1639
1640         kobject_del(&glob->kobj);
1641         kobject_put(&glob->kobj);
1642         ttm_mem_global_release(&ttm_mem_glob);
1643         memset(glob, 0, sizeof(*glob));
1644 out:
1645         mutex_unlock(&ttm_global_mutex);
1646 }
1647
1648 static int ttm_bo_global_init(void)
1649 {
1650         struct ttm_bo_global *glob = &ttm_bo_glob;
1651         int ret = 0;
1652         unsigned i;
1653
1654         mutex_lock(&ttm_global_mutex);
1655         if (++ttm_bo_glob_use_count > 1)
1656                 goto out;
1657
1658         ret = ttm_mem_global_init(&ttm_mem_glob);
1659         if (ret)
1660                 goto out;
1661
1662         spin_lock_init(&glob->lru_lock);
1663         glob->mem_glob = &ttm_mem_glob;
1664         glob->mem_glob->bo_glob = glob;
1665         glob->dummy_read_page = alloc_page(__GFP_ZERO | GFP_DMA32);
1666
1667         if (unlikely(glob->dummy_read_page == NULL)) {
1668                 ret = -ENOMEM;
1669                 goto out;
1670         }
1671
1672         for (i = 0; i < TTM_MAX_BO_PRIORITY; ++i)
1673                 INIT_LIST_HEAD(&glob->swap_lru[i]);
1674         INIT_LIST_HEAD(&glob->device_list);
1675         atomic_set(&glob->bo_count, 0);
1676
1677         ret = kobject_init_and_add(
1678                 &glob->kobj, &ttm_bo_glob_kobj_type, ttm_get_kobj(), "buffer_objects");
1679         if (unlikely(ret != 0))
1680                 kobject_put(&glob->kobj);
1681 out:
1682         mutex_unlock(&ttm_global_mutex);
1683         return ret;
1684 }
1685
1686 int ttm_bo_device_release(struct ttm_bo_device *bdev)
1687 {
1688         int ret = 0;
1689         unsigned i = TTM_NUM_MEM_TYPES;
1690         struct ttm_mem_type_manager *man;
1691         struct ttm_bo_global *glob = bdev->glob;
1692
1693         while (i--) {
1694                 man = &bdev->man[i];
1695                 if (man->has_type) {
1696                         man->use_type = false;
1697                         if ((i != TTM_PL_SYSTEM) && ttm_bo_clean_mm(bdev, i)) {
1698                                 ret = -EBUSY;
1699                                 pr_err("DRM memory manager type %d is not clean\n",
1700                                        i);
1701                         }
1702                         man->has_type = false;
1703                 }
1704         }
1705
1706         mutex_lock(&ttm_global_mutex);
1707         list_del(&bdev->device_list);
1708         mutex_unlock(&ttm_global_mutex);
1709
1710         cancel_delayed_work_sync(&bdev->wq);
1711
1712         if (ttm_bo_delayed_delete(bdev, true))
1713                 pr_debug("Delayed destroy list was clean\n");
1714
1715         spin_lock(&glob->lru_lock);
1716         for (i = 0; i < TTM_MAX_BO_PRIORITY; ++i)
1717                 if (list_empty(&bdev->man[0].lru[0]))
1718                         pr_debug("Swap list %d was clean\n", i);
1719         spin_unlock(&glob->lru_lock);
1720
1721         drm_vma_offset_manager_destroy(&bdev->vma_manager);
1722
1723         if (!ret)
1724                 ttm_bo_global_release();
1725
1726         return ret;
1727 }
1728 EXPORT_SYMBOL(ttm_bo_device_release);
1729
1730 int ttm_bo_device_init(struct ttm_bo_device *bdev,
1731                        struct ttm_bo_driver *driver,
1732                        struct address_space *mapping,
1733                        bool need_dma32)
1734 {
1735         struct ttm_bo_global *glob = &ttm_bo_glob;
1736         int ret;
1737
1738         ret = ttm_bo_global_init();
1739         if (ret)
1740                 return ret;
1741
1742         bdev->driver = driver;
1743
1744         memset(bdev->man, 0, sizeof(bdev->man));
1745
1746         /*
1747          * Initialize the system memory buffer type.
1748          * Other types need to be driver / IOCTL initialized.
1749          */
1750         ret = ttm_bo_init_mm(bdev, TTM_PL_SYSTEM, 0);
1751         if (unlikely(ret != 0))
1752                 goto out_no_sys;
1753
1754         drm_vma_offset_manager_init(&bdev->vma_manager,
1755                                     DRM_FILE_PAGE_OFFSET_START,
1756                                     DRM_FILE_PAGE_OFFSET_SIZE);
1757         INIT_DELAYED_WORK(&bdev->wq, ttm_bo_delayed_workqueue);
1758         INIT_LIST_HEAD(&bdev->ddestroy);
1759         bdev->dev_mapping = mapping;
1760         bdev->glob = glob;
1761         bdev->need_dma32 = need_dma32;
1762         mutex_lock(&ttm_global_mutex);
1763         list_add_tail(&bdev->device_list, &glob->device_list);
1764         mutex_unlock(&ttm_global_mutex);
1765
1766         return 0;
1767 out_no_sys:
1768         ttm_bo_global_release();
1769         return ret;
1770 }
1771 EXPORT_SYMBOL(ttm_bo_device_init);
1772
1773 /*
1774  * buffer object vm functions.
1775  */
1776
1777 bool ttm_mem_reg_is_pci(struct ttm_bo_device *bdev, struct ttm_mem_reg *mem)
1778 {
1779         struct ttm_mem_type_manager *man = &bdev->man[mem->mem_type];
1780
1781         if (!(man->flags & TTM_MEMTYPE_FLAG_FIXED)) {
1782                 if (mem->mem_type == TTM_PL_SYSTEM)
1783                         return false;
1784
1785                 if (man->flags & TTM_MEMTYPE_FLAG_CMA)
1786                         return false;
1787
1788                 if (mem->placement & TTM_PL_FLAG_CACHED)
1789                         return false;
1790         }
1791         return true;
1792 }
1793
1794 void ttm_bo_unmap_virtual_locked(struct ttm_buffer_object *bo)
1795 {
1796         struct ttm_bo_device *bdev = bo->bdev;
1797
1798         drm_vma_node_unmap(&bo->base.vma_node, bdev->dev_mapping);
1799         ttm_mem_io_free_vm(bo);
1800 }
1801
1802 void ttm_bo_unmap_virtual(struct ttm_buffer_object *bo)
1803 {
1804         struct ttm_bo_device *bdev = bo->bdev;
1805         struct ttm_mem_type_manager *man = &bdev->man[bo->mem.mem_type];
1806
1807         ttm_mem_io_lock(man, false);
1808         ttm_bo_unmap_virtual_locked(bo);
1809         ttm_mem_io_unlock(man);
1810 }
1811
1812
1813 EXPORT_SYMBOL(ttm_bo_unmap_virtual);
1814
1815 int ttm_bo_wait(struct ttm_buffer_object *bo,
1816                 bool interruptible, bool no_wait)
1817 {
1818         long timeout = 15 * HZ;
1819
1820         if (no_wait) {
1821                 if (dma_resv_test_signaled_rcu(bo->base.resv, true))
1822                         return 0;
1823                 else
1824                         return -EBUSY;
1825         }
1826
1827         timeout = dma_resv_wait_timeout_rcu(bo->base.resv, true,
1828                                                       interruptible, timeout);
1829         if (timeout < 0)
1830                 return timeout;
1831
1832         if (timeout == 0)
1833                 return -EBUSY;
1834
1835         dma_resv_add_excl_fence(bo->base.resv, NULL);
1836         return 0;
1837 }
1838 EXPORT_SYMBOL(ttm_bo_wait);
1839
1840 int ttm_bo_synccpu_write_grab(struct ttm_buffer_object *bo, bool no_wait)
1841 {
1842         int ret = 0;
1843
1844         /*
1845          * Using ttm_bo_reserve makes sure the lru lists are updated.
1846          */
1847
1848         ret = ttm_bo_reserve(bo, true, no_wait, NULL);
1849         if (unlikely(ret != 0))
1850                 return ret;
1851         ret = ttm_bo_wait(bo, true, no_wait);
1852         if (likely(ret == 0))
1853                 atomic_inc(&bo->cpu_writers);
1854         ttm_bo_unreserve(bo);
1855         return ret;
1856 }
1857 EXPORT_SYMBOL(ttm_bo_synccpu_write_grab);
1858
1859 void ttm_bo_synccpu_write_release(struct ttm_buffer_object *bo)
1860 {
1861         atomic_dec(&bo->cpu_writers);
1862 }
1863 EXPORT_SYMBOL(ttm_bo_synccpu_write_release);
1864
1865 /**
1866  * A buffer object shrink method that tries to swap out the first
1867  * buffer object on the bo_global::swap_lru list.
1868  */
1869 int ttm_bo_swapout(struct ttm_bo_global *glob, struct ttm_operation_ctx *ctx)
1870 {
1871         struct ttm_buffer_object *bo;
1872         int ret = -EBUSY;
1873         bool locked;
1874         unsigned i;
1875
1876         spin_lock(&glob->lru_lock);
1877         for (i = 0; i < TTM_MAX_BO_PRIORITY; ++i) {
1878                 list_for_each_entry(bo, &glob->swap_lru[i], swap) {
1879                         if (ttm_bo_evict_swapout_allowable(bo, ctx, &locked,
1880                                                            NULL)) {
1881                                 ret = 0;
1882                                 break;
1883                         }
1884                 }
1885                 if (!ret)
1886                         break;
1887         }
1888
1889         if (ret) {
1890                 spin_unlock(&glob->lru_lock);
1891                 return ret;
1892         }
1893
1894         kref_get(&bo->list_kref);
1895
1896         if (!list_empty(&bo->ddestroy)) {
1897                 ret = ttm_bo_cleanup_refs(bo, false, false, locked);
1898                 kref_put(&bo->list_kref, ttm_bo_release_list);
1899                 return ret;
1900         }
1901
1902         ttm_bo_del_from_lru(bo);
1903         spin_unlock(&glob->lru_lock);
1904
1905         /**
1906          * Move to system cached
1907          */
1908
1909         if (bo->mem.mem_type != TTM_PL_SYSTEM ||
1910             bo->ttm->caching_state != tt_cached) {
1911                 struct ttm_operation_ctx ctx = { false, false };
1912                 struct ttm_mem_reg evict_mem;
1913
1914                 evict_mem = bo->mem;
1915                 evict_mem.mm_node = NULL;
1916                 evict_mem.placement = TTM_PL_FLAG_SYSTEM | TTM_PL_FLAG_CACHED;
1917                 evict_mem.mem_type = TTM_PL_SYSTEM;
1918
1919                 ret = ttm_bo_handle_move_mem(bo, &evict_mem, true, &ctx);
1920                 if (unlikely(ret != 0))
1921                         goto out;
1922         }
1923
1924         /**
1925          * Make sure BO is idle.
1926          */
1927
1928         ret = ttm_bo_wait(bo, false, false);
1929         if (unlikely(ret != 0))
1930                 goto out;
1931
1932         ttm_bo_unmap_virtual(bo);
1933
1934         /**
1935          * Swap out. Buffer will be swapped in again as soon as
1936          * anyone tries to access a ttm page.
1937          */
1938
1939         if (bo->bdev->driver->swap_notify)
1940                 bo->bdev->driver->swap_notify(bo);
1941
1942         ret = ttm_tt_swapout(bo->ttm, bo->persistent_swap_storage);
1943 out:
1944
1945         /**
1946          *
1947          * Unreserve without putting on LRU to avoid swapping out an
1948          * already swapped buffer.
1949          */
1950         if (locked)
1951                 dma_resv_unlock(bo->base.resv);
1952         kref_put(&bo->list_kref, ttm_bo_release_list);
1953         return ret;
1954 }
1955 EXPORT_SYMBOL(ttm_bo_swapout);
1956
1957 void ttm_bo_swapout_all(struct ttm_bo_device *bdev)
1958 {
1959         struct ttm_operation_ctx ctx = {
1960                 .interruptible = false,
1961                 .no_wait_gpu = false
1962         };
1963
1964         while (ttm_bo_swapout(bdev->glob, &ctx) == 0)
1965                 ;
1966 }
1967 EXPORT_SYMBOL(ttm_bo_swapout_all);
1968
1969 /**
1970  * ttm_bo_wait_unreserved - interruptible wait for a buffer object to become
1971  * unreserved
1972  *
1973  * @bo: Pointer to buffer
1974  */
1975 int ttm_bo_wait_unreserved(struct ttm_buffer_object *bo)
1976 {
1977         int ret;
1978
1979         /*
1980          * In the absense of a wait_unlocked API,
1981          * Use the bo::wu_mutex to avoid triggering livelocks due to
1982          * concurrent use of this function. Note that this use of
1983          * bo::wu_mutex can go away if we change locking order to
1984          * mmap_sem -> bo::reserve.
1985          */
1986         ret = mutex_lock_interruptible(&bo->wu_mutex);
1987         if (unlikely(ret != 0))
1988                 return -ERESTARTSYS;
1989         if (!dma_resv_is_locked(bo->base.resv))
1990                 goto out_unlock;
1991         ret = dma_resv_lock_interruptible(bo->base.resv, NULL);
1992         if (ret == -EINTR)
1993                 ret = -ERESTARTSYS;
1994         if (unlikely(ret != 0))
1995                 goto out_unlock;
1996         dma_resv_unlock(bo->base.resv);
1997
1998 out_unlock:
1999         mutex_unlock(&bo->wu_mutex);
2000         return ret;
2001 }