xref: /dragonfly/sys/dev/drm/ttm/ttm_bo.c (revision 31524921)
1 /**************************************************************************
2  *
3  * Copyright (c) 2006-2009 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 #define pr_fmt(fmt) "[TTM] " fmt
32 
33 #include <drm/ttm/ttm_module.h>
34 #include <drm/ttm/ttm_bo_driver.h>
35 #include <drm/ttm/ttm_placement.h>
36 #include <linux/atomic.h>
37 #include <linux/errno.h>
38 #include <linux/export.h>
39 #include <linux/wait.h>
40 
41 #define TTM_ASSERT_LOCKED(param)
42 #define TTM_DEBUG(fmt, arg...)
43 #define TTM_BO_HASH_ORDER 13
44 
45 static int ttm_bo_setup_vm(struct ttm_buffer_object *bo);
46 static int ttm_bo_swapout(struct ttm_mem_shrink *shrink);
47 static void ttm_bo_global_kobj_release(struct ttm_bo_global *glob);
48 
49 static inline int ttm_mem_type_from_flags(uint32_t flags, uint32_t *mem_type)
50 {
51 	int i;
52 
53 	for (i = 0; i <= TTM_PL_PRIV5; i++)
54 		if (flags & (1 << i)) {
55 			*mem_type = i;
56 			return 0;
57 		}
58 	return -EINVAL;
59 }
60 
61 static void ttm_mem_type_debug(struct ttm_bo_device *bdev, int mem_type)
62 {
63 	struct ttm_mem_type_manager *man = &bdev->man[mem_type];
64 
65 	kprintf("    has_type: %d\n", man->has_type);
66 	kprintf("    use_type: %d\n", man->use_type);
67 	kprintf("    flags: 0x%08X\n", man->flags);
68 	kprintf("    gpu_offset: 0x%08lX\n", man->gpu_offset);
69 	kprintf("    size: %ju\n", (uintmax_t)man->size);
70 	kprintf("    available_caching: 0x%08X\n", man->available_caching);
71 	kprintf("    default_caching: 0x%08X\n", man->default_caching);
72 	if (mem_type != TTM_PL_SYSTEM)
73 		(*man->func->debug)(man, TTM_PFX);
74 }
75 
76 static void ttm_bo_mem_space_debug(struct ttm_buffer_object *bo,
77 					struct ttm_placement *placement)
78 {
79 	int i, ret, mem_type;
80 
81 	kprintf("No space for %p (%lu pages, %luK, %luM)\n",
82 	       bo, bo->mem.num_pages, bo->mem.size >> 10,
83 	       bo->mem.size >> 20);
84 	for (i = 0; i < placement->num_placement; i++) {
85 		ret = ttm_mem_type_from_flags(placement->placement[i],
86 						&mem_type);
87 		if (ret)
88 			return;
89 		kprintf("  placement[%d]=0x%08X (%d)\n",
90 		       i, placement->placement[i], mem_type);
91 		ttm_mem_type_debug(bo->bdev, mem_type);
92 	}
93 }
94 
95 #if 0
96 static ssize_t ttm_bo_global_show(struct ttm_bo_global *glob,
97     char *buffer)
98 {
99 
100 	return snprintf(buffer, PAGE_SIZE, "%lu\n",
101 			(unsigned long) atomic_read(&glob->bo_count));
102 }
103 #endif
104 
105 static inline uint32_t ttm_bo_type_flags(unsigned type)
106 {
107 	return 1 << (type);
108 }
109 
110 static void ttm_bo_release_list(struct kref *list_kref)
111 {
112 	struct ttm_buffer_object *bo =
113 	    container_of(list_kref, struct ttm_buffer_object, list_kref);
114 	struct ttm_bo_device *bdev = bo->bdev;
115 	size_t acc_size = bo->acc_size;
116 
117 	BUG_ON(atomic_read(&bo->list_kref.refcount));
118 	BUG_ON(atomic_read(&bo->kref.refcount));
119 	BUG_ON(atomic_read(&bo->cpu_writers));
120 	BUG_ON(bo->sync_obj != NULL);
121 	BUG_ON(bo->mem.mm_node != NULL);
122 	BUG_ON(!list_empty(&bo->lru));
123 	BUG_ON(!list_empty(&bo->ddestroy));
124 
125 	if (bo->ttm)
126 		ttm_tt_destroy(bo->ttm);
127 	atomic_dec(&bo->glob->bo_count);
128 	if (bo->destroy)
129 		bo->destroy(bo);
130 	else {
131 		kfree(bo);
132 	}
133 	ttm_mem_global_free(bdev->glob->mem_glob, acc_size);
134 }
135 
136 static int ttm_bo_wait_unreserved(struct ttm_buffer_object *bo,
137 				  bool interruptible)
138 {
139 	if (interruptible) {
140 		return wait_event_interruptible(bo->event_queue,
141 					       !ttm_bo_is_reserved(bo));
142 	} else {
143 		wait_event(bo->event_queue, !ttm_bo_is_reserved(bo));
144 		return 0;
145 	}
146 }
147 
148 void ttm_bo_add_to_lru(struct ttm_buffer_object *bo)
149 {
150 	struct ttm_bo_device *bdev = bo->bdev;
151 	struct ttm_mem_type_manager *man;
152 
153 	BUG_ON(!ttm_bo_is_reserved(bo));
154 
155 	if (!(bo->mem.placement & TTM_PL_FLAG_NO_EVICT)) {
156 
157 		BUG_ON(!list_empty(&bo->lru));
158 
159 		man = &bdev->man[bo->mem.mem_type];
160 		list_add_tail(&bo->lru, &man->lru);
161 		kref_get(&bo->list_kref);
162 
163 		if (bo->ttm != NULL) {
164 			list_add_tail(&bo->swap, &bo->glob->swap_lru);
165 			kref_get(&bo->list_kref);
166 		}
167 	}
168 }
169 
170 int ttm_bo_del_from_lru(struct ttm_buffer_object *bo)
171 {
172 	int put_count = 0;
173 
174 	if (!list_empty(&bo->swap)) {
175 		list_del_init(&bo->swap);
176 		++put_count;
177 	}
178 	if (!list_empty(&bo->lru)) {
179 		list_del_init(&bo->lru);
180 		++put_count;
181 	}
182 
183 	/*
184 	 * TODO: Add a driver hook to delete from
185 	 * driver-specific LRU's here.
186 	 */
187 
188 	return put_count;
189 }
190 
191 int ttm_bo_reserve_nolru(struct ttm_buffer_object *bo,
192 			  bool interruptible,
193 			  bool no_wait, bool use_ticket,
194 			  struct ww_acquire_ctx *ticket)
195 {
196 	int ret;
197 
198 	while (unlikely(atomic_xchg(&bo->reserved, 1) != 0)) {
199 		/**
200 		 * Deadlock avoidance for multi-bo reserving.
201 		 */
202 		if (use_ticket && bo->seq_valid) {
203 			/**
204 			 * We've already reserved this one.
205 			 */
206 			if (unlikely(ticket->stamp == bo->val_seq))
207 				return -EDEADLK;
208 			/**
209 			 * Already reserved by a thread that will not back
210 			 * off for us. We need to back off.
211 			 */
212 			if (unlikely(ticket->stamp - bo->val_seq <= LONG_MAX))
213 				return -EAGAIN;
214 		}
215 
216 		if (no_wait)
217 			return -EBUSY;
218 
219 		ret = ttm_bo_wait_unreserved(bo, interruptible);
220 
221 		if (unlikely(ret))
222 			return ret;
223 	}
224 
225 	if (use_ticket) {
226 		bool wake_up = false;
227 
228 		/**
229 		 * Wake up waiters that may need to recheck for deadlock,
230 		 * if we decreased the sequence number.
231 		 */
232 		if (unlikely((bo->val_seq - ticket->stamp <= LONG_MAX)
233 			     || !bo->seq_valid))
234 			wake_up = true;
235 
236 		/*
237 		 * In the worst case with memory ordering these values can be
238 		 * seen in the wrong order. However since we call wake_up_all
239 		 * in that case, this will hopefully not pose a problem,
240 		 * and the worst case would only cause someone to accidentally
241 		 * hit -EAGAIN in ttm_bo_reserve when they see old value of
242 		 * val_seq. However this would only happen if seq_valid was
243 		 * written before val_seq was, and just means some slightly
244 		 * increased cpu usage
245 		 */
246 		bo->val_seq = ticket->stamp;
247 		bo->seq_valid = true;
248 		if (wake_up)
249 			wake_up_all(&bo->event_queue);
250 	} else {
251 		bo->seq_valid = false;
252 	}
253 
254 	return 0;
255 }
256 EXPORT_SYMBOL(ttm_bo_reserve);
257 
258 static void ttm_bo_ref_bug(struct kref *list_kref)
259 {
260 	BUG();
261 }
262 
263 void ttm_bo_list_ref_sub(struct ttm_buffer_object *bo, int count,
264 			 bool never_free)
265 {
266 	kref_sub(&bo->list_kref, count,
267 		 (never_free) ? ttm_bo_ref_bug : ttm_bo_release_list);
268 }
269 
270 int ttm_bo_reserve(struct ttm_buffer_object *bo,
271 		   bool interruptible,
272 		   bool no_wait, bool use_ticket,
273 		   struct ww_acquire_ctx *ticket)
274 {
275 	struct ttm_bo_global *glob = bo->glob;
276 	int put_count = 0;
277 	int ret;
278 
279 	ret = ttm_bo_reserve_nolru(bo, interruptible, no_wait, use_ticket,
280 				    ticket);
281 	if (likely(ret == 0)) {
282 		lockmgr(&glob->lru_lock, LK_EXCLUSIVE);
283 		put_count = ttm_bo_del_from_lru(bo);
284 		lockmgr(&glob->lru_lock, LK_RELEASE);
285 		ttm_bo_list_ref_sub(bo, put_count, true);
286 	}
287 
288 	return ret;
289 }
290 
291 int ttm_bo_reserve_slowpath_nolru(struct ttm_buffer_object *bo,
292 				  bool interruptible,
293 				  struct ww_acquire_ctx *ticket)
294 {
295 	bool wake_up = false;
296 	int ret;
297 
298 	while (unlikely(atomic_xchg(&bo->reserved, 1) != 0)) {
299 		WARN_ON(bo->seq_valid && ticket->stamp == bo->val_seq);
300 
301 		ret = ttm_bo_wait_unreserved(bo, interruptible);
302 
303 		if (unlikely(ret))
304 			return ret;
305 	}
306 
307 	if (bo->val_seq - ticket->stamp < LONG_MAX || !bo->seq_valid)
308 		wake_up = true;
309 
310 	/**
311 	 * Wake up waiters that may need to recheck for deadlock,
312 	 * if we decreased the sequence number.
313 	 */
314 	bo->val_seq = ticket->stamp;
315 	bo->seq_valid = true;
316 	if (wake_up)
317 		wake_up_all(&bo->event_queue);
318 
319 	return 0;
320 }
321 
322 int ttm_bo_reserve_slowpath(struct ttm_buffer_object *bo,
323 			    bool interruptible, struct ww_acquire_ctx *ticket)
324 {
325 	struct ttm_bo_global *glob = bo->glob;
326 	int put_count, ret;
327 
328 	ret = ttm_bo_reserve_slowpath_nolru(bo, interruptible, ticket);
329 	if (likely(!ret)) {
330 		lockmgr(&glob->lru_lock, LK_EXCLUSIVE);
331 		put_count = ttm_bo_del_from_lru(bo);
332 		lockmgr(&glob->lru_lock, LK_RELEASE);
333 		ttm_bo_list_ref_sub(bo, put_count, true);
334 	}
335 	return ret;
336 }
337 EXPORT_SYMBOL(ttm_bo_reserve_slowpath);
338 
339 /*
340  * Must interlock with event_queue to avoid race against
341  * wait_event_common() which can cause wait_event_common()
342  * to become stuck.
343  */
344 static void
345 ttm_bo_unreserve_core(struct ttm_buffer_object *bo)
346 {
347 	lockmgr(&bo->event_queue.lock, LK_EXCLUSIVE);
348 	atomic_set(&bo->reserved, 0);
349 	lockmgr(&bo->event_queue.lock, LK_RELEASE);
350 	wake_up_all(&bo->event_queue);
351 }
352 
353 void ttm_bo_unreserve_ticket_locked(struct ttm_buffer_object *bo, struct ww_acquire_ctx *ticket)
354 {
355 	ttm_bo_add_to_lru(bo);
356 	ttm_bo_unreserve_core(bo);
357 }
358 
359 void ttm_bo_unreserve(struct ttm_buffer_object *bo)
360 {
361 	struct ttm_bo_global *glob = bo->glob;
362 
363 	lockmgr(&glob->lru_lock, LK_EXCLUSIVE);
364 	ttm_bo_unreserve_ticket_locked(bo, NULL);
365 	lockmgr(&glob->lru_lock, LK_RELEASE);
366 }
367 EXPORT_SYMBOL(ttm_bo_unreserve);
368 
369 void ttm_bo_unreserve_ticket(struct ttm_buffer_object *bo, struct ww_acquire_ctx *ticket)
370 {
371 	struct ttm_bo_global *glob = bo->glob;
372 
373 	lockmgr(&glob->lru_lock, LK_EXCLUSIVE);
374 	ttm_bo_unreserve_ticket_locked(bo, ticket);
375 	lockmgr(&glob->lru_lock, LK_RELEASE);
376 }
377 EXPORT_SYMBOL(ttm_bo_unreserve_ticket);
378 
379 /*
380  * Call bo->mutex locked.
381  */
382 static int ttm_bo_add_ttm(struct ttm_buffer_object *bo, bool zero_alloc)
383 {
384 	struct ttm_bo_device *bdev = bo->bdev;
385 	struct ttm_bo_global *glob = bo->glob;
386 	int ret = 0;
387 	uint32_t page_flags = 0;
388 
389 	TTM_ASSERT_LOCKED(&bo->mutex);
390 	bo->ttm = NULL;
391 
392 	if (bdev->need_dma32)
393 		page_flags |= TTM_PAGE_FLAG_DMA32;
394 
395 	switch (bo->type) {
396 	case ttm_bo_type_device:
397 		if (zero_alloc)
398 			page_flags |= TTM_PAGE_FLAG_ZERO_ALLOC;
399 	case ttm_bo_type_kernel:
400 		bo->ttm = bdev->driver->ttm_tt_create(bdev, bo->num_pages << PAGE_SHIFT,
401 						      page_flags, glob->dummy_read_page);
402 		if (unlikely(bo->ttm == NULL))
403 			ret = -ENOMEM;
404 		break;
405 	case ttm_bo_type_sg:
406 		bo->ttm = bdev->driver->ttm_tt_create(bdev, bo->num_pages << PAGE_SHIFT,
407 						      page_flags | TTM_PAGE_FLAG_SG,
408 						      glob->dummy_read_page);
409 		if (unlikely(bo->ttm == NULL)) {
410 			ret = -ENOMEM;
411 			break;
412 		}
413 		bo->ttm->sg = bo->sg;
414 		break;
415 	default:
416 		kprintf("[TTM] Illegal buffer object type\n");
417 		ret = -EINVAL;
418 		break;
419 	}
420 
421 	return ret;
422 }
423 
424 static int ttm_bo_handle_move_mem(struct ttm_buffer_object *bo,
425 				  struct ttm_mem_reg *mem,
426 				  bool evict, bool interruptible,
427 				  bool no_wait_gpu)
428 {
429 	struct ttm_bo_device *bdev = bo->bdev;
430 	bool old_is_pci = ttm_mem_reg_is_pci(bdev, &bo->mem);
431 	bool new_is_pci = ttm_mem_reg_is_pci(bdev, mem);
432 	struct ttm_mem_type_manager *old_man = &bdev->man[bo->mem.mem_type];
433 	struct ttm_mem_type_manager *new_man = &bdev->man[mem->mem_type];
434 	int ret = 0;
435 
436 	if (old_is_pci || new_is_pci ||
437 	    ((mem->placement & bo->mem.placement & TTM_PL_MASK_CACHING) == 0)) {
438 		ret = ttm_mem_io_lock(old_man, true);
439 		if (unlikely(ret != 0))
440 			goto out_err;
441 		ttm_bo_unmap_virtual_locked(bo);
442 		ttm_mem_io_unlock(old_man);
443 	}
444 
445 	/*
446 	 * Create and bind a ttm if required.
447 	 */
448 
449 	if (!(new_man->flags & TTM_MEMTYPE_FLAG_FIXED)) {
450 		if (bo->ttm == NULL) {
451 			bool zero = !(old_man->flags & TTM_MEMTYPE_FLAG_FIXED);
452 			ret = ttm_bo_add_ttm(bo, zero);
453 			if (ret)
454 				goto out_err;
455 		}
456 
457 		ret = ttm_tt_set_placement_caching(bo->ttm, mem->placement);
458 		if (ret)
459 			goto out_err;
460 
461 		if (mem->mem_type != TTM_PL_SYSTEM) {
462 			ret = ttm_tt_bind(bo->ttm, mem);
463 			if (ret)
464 				goto out_err;
465 		}
466 
467 		if (bo->mem.mem_type == TTM_PL_SYSTEM) {
468 			if (bdev->driver->move_notify)
469 				bdev->driver->move_notify(bo, mem);
470 			bo->mem = *mem;
471 			mem->mm_node = NULL;
472 			goto moved;
473 		}
474 	}
475 
476 	if (bdev->driver->move_notify)
477 		bdev->driver->move_notify(bo, mem);
478 
479 	if (!(old_man->flags & TTM_MEMTYPE_FLAG_FIXED) &&
480 	    !(new_man->flags & TTM_MEMTYPE_FLAG_FIXED))
481 		ret = ttm_bo_move_ttm(bo, evict, no_wait_gpu, mem);
482 	else if (bdev->driver->move)
483 		ret = bdev->driver->move(bo, evict, interruptible,
484 					 no_wait_gpu, mem);
485 	else
486 		ret = ttm_bo_move_memcpy(bo, evict, no_wait_gpu, mem);
487 
488 	if (ret) {
489 		if (bdev->driver->move_notify) {
490 			struct ttm_mem_reg tmp_mem = *mem;
491 			*mem = bo->mem;
492 			bo->mem = tmp_mem;
493 			bdev->driver->move_notify(bo, mem);
494 			bo->mem = *mem;
495 			*mem = tmp_mem;
496 		}
497 
498 		goto out_err;
499 	}
500 
501 moved:
502 	if (bo->evicted) {
503 		ret = bdev->driver->invalidate_caches(bdev, bo->mem.placement);
504 		if (ret)
505 			kprintf("[TTM] Can not flush read caches\n");
506 		bo->evicted = false;
507 	}
508 
509 	if (bo->mem.mm_node) {
510 		bo->offset = (bo->mem.start << PAGE_SHIFT) +
511 		    bdev->man[bo->mem.mem_type].gpu_offset;
512 		bo->cur_placement = bo->mem.placement;
513 	} else
514 		bo->offset = 0;
515 
516 	return 0;
517 
518 out_err:
519 	new_man = &bdev->man[bo->mem.mem_type];
520 	if ((new_man->flags & TTM_MEMTYPE_FLAG_FIXED) && bo->ttm) {
521 		ttm_tt_unbind(bo->ttm);
522 		ttm_tt_destroy(bo->ttm);
523 		bo->ttm = NULL;
524 	}
525 
526 	return ret;
527 }
528 
529 /**
530  * Call bo::reserved.
531  * Will release GPU memory type usage on destruction.
532  * This is the place to put in driver specific hooks to release
533  * driver private resources.
534  * Will release the bo::reserved lock.
535  */
536 
537 static void ttm_bo_cleanup_memtype_use(struct ttm_buffer_object *bo)
538 {
539 	if (bo->bdev->driver->move_notify)
540 		bo->bdev->driver->move_notify(bo, NULL);
541 
542 	if (bo->ttm) {
543 		ttm_tt_unbind(bo->ttm);
544 		ttm_tt_destroy(bo->ttm);
545 		bo->ttm = NULL;
546 	}
547 	ttm_bo_mem_put(bo, &bo->mem);
548 	ttm_bo_unreserve_core(bo);
549 
550 	/*
551 	 * Since the final reference to this bo may not be dropped by
552 	 * the current task we have to put a memory barrier here to make
553 	 * sure the changes done in this function are always visible.
554 	 *
555 	 * This function only needs protection against the final kref_put.
556 	 */
557 	cpu_mfence();
558 }
559 
560 static void ttm_bo_cleanup_refs_or_queue(struct ttm_buffer_object *bo)
561 {
562 	struct ttm_bo_device *bdev = bo->bdev;
563 	struct ttm_bo_global *glob = bo->glob;
564 	struct ttm_bo_driver *driver = bdev->driver;
565 	void *sync_obj = NULL;
566 	int put_count;
567 	int ret;
568 
569 	lockmgr(&glob->lru_lock, LK_EXCLUSIVE);
570 	ret = ttm_bo_reserve_nolru(bo, false, true, false, 0);
571 
572 	lockmgr(&bdev->fence_lock, LK_EXCLUSIVE);
573 	(void) ttm_bo_wait(bo, false, false, true);
574 	if (!ret && !bo->sync_obj) {
575 		lockmgr(&bdev->fence_lock, LK_RELEASE);
576 		put_count = ttm_bo_del_from_lru(bo);
577 
578 		lockmgr(&glob->lru_lock, LK_RELEASE);
579 		ttm_bo_cleanup_memtype_use(bo);
580 
581 		ttm_bo_list_ref_sub(bo, put_count, true);
582 
583 		return;
584 	}
585 	if (bo->sync_obj)
586 		sync_obj = driver->sync_obj_ref(bo->sync_obj);
587 	lockmgr(&bdev->fence_lock, LK_RELEASE);
588 
589 	if (!ret) {
590 
591 		/*
592 		 * Make NO_EVICT bos immediately available to
593 		 * shrinkers, now that they are queued for
594 		 * destruction.
595 		 */
596 		if (bo->mem.placement & TTM_PL_FLAG_NO_EVICT) {
597 			bo->mem.placement &= ~TTM_PL_FLAG_NO_EVICT;
598 			ttm_bo_add_to_lru(bo);
599 		}
600 
601 		ttm_bo_unreserve_core(bo);
602 	}
603 
604 	kref_get(&bo->list_kref);
605 	list_add_tail(&bo->ddestroy, &bdev->ddestroy);
606 	lockmgr(&glob->lru_lock, LK_RELEASE);
607 
608 	if (sync_obj) {
609 		driver->sync_obj_flush(sync_obj);
610 		driver->sync_obj_unref(&sync_obj);
611 	}
612 	schedule_delayed_work(&bdev->wq,
613 			      ((hz / 100) < 1) ? 1 : hz / 100);
614 }
615 
616 /**
617  * function ttm_bo_cleanup_refs_and_unlock
618  * If bo idle, remove from delayed- and lru lists, and unref.
619  * If not idle, do nothing.
620  *
621  * Must be called with lru_lock and reservation held, this function
622  * will drop both before returning.
623  *
624  * @interruptible         Any sleeps should occur interruptibly.
625  * @no_wait_gpu           Never wait for gpu. Return -EBUSY instead.
626  */
627 
628 static int ttm_bo_cleanup_refs_and_unlock(struct ttm_buffer_object *bo,
629 					  bool interruptible,
630 					  bool no_wait_gpu)
631 {
632 	struct ttm_bo_device *bdev = bo->bdev;
633 	struct ttm_bo_driver *driver = bdev->driver;
634 	struct ttm_bo_global *glob = bo->glob;
635 	int put_count;
636 	int ret;
637 
638 	lockmgr(&bdev->fence_lock, LK_EXCLUSIVE);
639 	ret = ttm_bo_wait(bo, false, false, true);
640 
641 	if (ret && !no_wait_gpu) {
642 		void *sync_obj;
643 
644 		/*
645 		 * Take a reference to the fence and unreserve,
646 		 * at this point the buffer should be dead, so
647 		 * no new sync objects can be attached.
648 		 */
649 		sync_obj = driver->sync_obj_ref(bo->sync_obj);
650 		lockmgr(&bdev->fence_lock, LK_RELEASE);
651 
652 		ttm_bo_unreserve_core(bo);
653 		lockmgr(&glob->lru_lock, LK_RELEASE);
654 
655 		ret = driver->sync_obj_wait(sync_obj, false, interruptible);
656 		driver->sync_obj_unref(&sync_obj);
657 		if (ret)
658 			return ret;
659 
660 		/*
661 		 * remove sync_obj with ttm_bo_wait, the wait should be
662 		 * finished, and no new wait object should have been added.
663 		 */
664 		lockmgr(&bdev->fence_lock, LK_EXCLUSIVE);
665 		ret = ttm_bo_wait(bo, false, false, true);
666 		WARN_ON(ret);
667 		lockmgr(&bdev->fence_lock, LK_RELEASE);
668 		if (ret)
669 			return ret;
670 
671 		lockmgr(&glob->lru_lock, LK_EXCLUSIVE);
672 		ret = ttm_bo_reserve_nolru(bo, false, true, false, 0);
673 
674 		/*
675 		 * We raced, and lost, someone else holds the reservation now,
676 		 * and is probably busy in ttm_bo_cleanup_memtype_use.
677 		 *
678 		 * Even if it's not the case, because we finished waiting any
679 		 * delayed destruction would succeed, so just return success
680 		 * here.
681 		 */
682 		if (ret) {
683 			lockmgr(&glob->lru_lock, LK_RELEASE);
684 			return 0;
685 		}
686 	} else
687 		lockmgr(&bdev->fence_lock, LK_RELEASE);
688 
689 	if (ret || unlikely(list_empty(&bo->ddestroy))) {
690 		ttm_bo_unreserve_core(bo);
691 		lockmgr(&glob->lru_lock, LK_RELEASE);
692 		return ret;
693 	}
694 
695 	put_count = ttm_bo_del_from_lru(bo);
696 	list_del_init(&bo->ddestroy);
697 	++put_count;
698 
699 	lockmgr(&glob->lru_lock, LK_RELEASE);
700 	ttm_bo_cleanup_memtype_use(bo);
701 
702 	ttm_bo_list_ref_sub(bo, put_count, true);
703 
704 	return 0;
705 }
706 
707 /**
708  * Traverse the delayed list, and call ttm_bo_cleanup_refs on all
709  * encountered buffers.
710  */
711 
712 static int ttm_bo_delayed_delete(struct ttm_bo_device *bdev, bool remove_all)
713 {
714 	struct ttm_bo_global *glob = bdev->glob;
715 	struct ttm_buffer_object *entry = NULL;
716 	int ret = 0;
717 
718 	lockmgr(&glob->lru_lock, LK_EXCLUSIVE);
719 	if (list_empty(&bdev->ddestroy))
720 		goto out_unlock;
721 
722 	entry = list_first_entry(&bdev->ddestroy,
723 		struct ttm_buffer_object, ddestroy);
724 	kref_get(&entry->list_kref);
725 
726 	for (;;) {
727 		struct ttm_buffer_object *nentry = NULL;
728 
729 		if (entry->ddestroy.next != &bdev->ddestroy) {
730 			nentry = list_first_entry(&entry->ddestroy,
731 				struct ttm_buffer_object, ddestroy);
732 			kref_get(&nentry->list_kref);
733 		}
734 
735 		ret = ttm_bo_reserve_nolru(entry, false, true, false, 0);
736 		if (remove_all && ret) {
737 			lockmgr(&glob->lru_lock, LK_RELEASE);
738 			ret = ttm_bo_reserve_nolru(entry, false, false,
739 						   false, 0);
740 			lockmgr(&glob->lru_lock, LK_EXCLUSIVE);
741 		}
742 
743 		if (!ret)
744 			ret = ttm_bo_cleanup_refs_and_unlock(entry, false,
745 							     !remove_all);
746 		else
747 			lockmgr(&glob->lru_lock, LK_RELEASE);
748 
749 		kref_put(&entry->list_kref, ttm_bo_release_list);
750 		entry = nentry;
751 
752 		if (ret || !entry)
753 			goto out;
754 
755 		lockmgr(&glob->lru_lock, LK_EXCLUSIVE);
756 		if (list_empty(&entry->ddestroy))
757 			break;
758 	}
759 
760 out_unlock:
761 	lockmgr(&glob->lru_lock, LK_RELEASE);
762 out:
763 	if (entry)
764 		kref_put(&entry->list_kref, ttm_bo_release_list);
765 	return ret;
766 }
767 
768 static void ttm_bo_delayed_workqueue(struct work_struct *work)
769 {
770 	struct ttm_bo_device *bdev =
771 	    container_of(work, struct ttm_bo_device, wq.work);
772 
773 	if (ttm_bo_delayed_delete(bdev, false)) {
774 		schedule_delayed_work(&bdev->wq,
775 				      ((hz / 100) < 1) ? 1 : hz / 100);
776 	}
777 }
778 
779 /*
780  * NOTE: bdev->vm_lock already held on call, this function release it.
781  */
782 static void ttm_bo_release(struct kref *kref)
783 {
784 	struct ttm_buffer_object *bo =
785 	    container_of(kref, struct ttm_buffer_object, kref);
786 	struct ttm_bo_device *bdev = bo->bdev;
787 	struct ttm_mem_type_manager *man = &bdev->man[bo->mem.mem_type];
788 	int release_active;
789 
790 	if (atomic_read(&bo->kref.refcount) > 0) {
791 		lockmgr(&bdev->vm_lock, LK_RELEASE);
792 		return;
793 	}
794 	if (likely(bo->vm_node != NULL)) {
795 		RB_REMOVE(ttm_bo_device_buffer_objects,
796 				&bdev->addr_space_rb, bo);
797 		drm_mm_put_block(bo->vm_node);
798 		bo->vm_node = NULL;
799 	}
800 
801 	/*
802 	 * Should we clean up our implied list_kref?  Because ttm_bo_release()
803 	 * can be called reentrantly due to races (this may not be true any
804 	 * more with the lock management changes in the deref), it is possible
805 	 * to get here twice, but there's only one list_kref ref to drop and
806 	 * in the other path 'bo' can be kfree()d by another thread the
807 	 * instant we release our lock.
808 	 */
809 	release_active = test_bit(TTM_BO_PRIV_FLAG_ACTIVE, &bo->priv_flags);
810 	if (release_active) {
811 		clear_bit(TTM_BO_PRIV_FLAG_ACTIVE, &bo->priv_flags);
812 		lockmgr(&bdev->vm_lock, LK_RELEASE);
813 		ttm_mem_io_lock(man, false);
814 		ttm_mem_io_free_vm(bo);
815 		ttm_mem_io_unlock(man);
816 		ttm_bo_cleanup_refs_or_queue(bo);
817 		kref_put(&bo->list_kref, ttm_bo_release_list);
818 	} else {
819 		lockmgr(&bdev->vm_lock, LK_RELEASE);
820 	}
821 }
822 
823 void ttm_bo_unref(struct ttm_buffer_object **p_bo)
824 {
825 	struct ttm_buffer_object *bo = *p_bo;
826 	struct ttm_bo_device *bdev = bo->bdev;
827 
828 	*p_bo = NULL;
829 	lockmgr(&bdev->vm_lock, LK_EXCLUSIVE);
830 	if (kref_put(&bo->kref, ttm_bo_release) == 0)
831 		lockmgr(&bdev->vm_lock, LK_RELEASE);
832 }
833 EXPORT_SYMBOL(ttm_bo_unref);
834 
835 int ttm_bo_lock_delayed_workqueue(struct ttm_bo_device *bdev)
836 {
837 	return cancel_delayed_work_sync(&bdev->wq);
838 }
839 EXPORT_SYMBOL(ttm_bo_lock_delayed_workqueue);
840 
841 void ttm_bo_unlock_delayed_workqueue(struct ttm_bo_device *bdev, int resched)
842 {
843 	if (resched)
844 		schedule_delayed_work(&bdev->wq,
845 				      ((hz / 100) < 1) ? 1 : hz / 100);
846 }
847 EXPORT_SYMBOL(ttm_bo_unlock_delayed_workqueue);
848 
849 static int ttm_bo_evict(struct ttm_buffer_object *bo, bool interruptible,
850 			bool no_wait_gpu)
851 {
852 	struct ttm_bo_device *bdev = bo->bdev;
853 	struct ttm_mem_reg evict_mem;
854 	struct ttm_placement placement;
855 	int ret = 0;
856 
857 	lockmgr(&bdev->fence_lock, LK_EXCLUSIVE);
858 	ret = ttm_bo_wait(bo, false, interruptible, no_wait_gpu);
859 	lockmgr(&bdev->fence_lock, LK_RELEASE);
860 
861 	if (unlikely(ret != 0)) {
862 		if (ret != -ERESTARTSYS) {
863 			pr_err("Failed to expire sync object before buffer eviction\n");
864 		}
865 		goto out;
866 	}
867 
868 	BUG_ON(!ttm_bo_is_reserved(bo));
869 
870 	evict_mem = bo->mem;
871 	evict_mem.mm_node = NULL;
872 	evict_mem.bus.io_reserved_vm = false;
873 	evict_mem.bus.io_reserved_count = 0;
874 
875 	placement.fpfn = 0;
876 	placement.lpfn = 0;
877 	placement.num_placement = 0;
878 	placement.num_busy_placement = 0;
879 	bdev->driver->evict_flags(bo, &placement);
880 	ret = ttm_bo_mem_space(bo, &placement, &evict_mem, interruptible,
881 				no_wait_gpu);
882 	if (ret) {
883 		if (ret != -ERESTARTSYS) {
884 			pr_err("Failed to find memory space for buffer 0x%p eviction\n",
885 			       bo);
886 			ttm_bo_mem_space_debug(bo, &placement);
887 		}
888 		goto out;
889 	}
890 
891 	ret = ttm_bo_handle_move_mem(bo, &evict_mem, true, interruptible,
892 				     no_wait_gpu);
893 	if (ret) {
894 		if (ret != -ERESTARTSYS)
895 			pr_err("Buffer eviction failed\n");
896 		ttm_bo_mem_put(bo, &evict_mem);
897 		goto out;
898 	}
899 	bo->evicted = true;
900 out:
901 	return ret;
902 }
903 
904 static int ttm_mem_evict_first(struct ttm_bo_device *bdev,
905 				uint32_t mem_type,
906 				bool interruptible,
907 				bool no_wait_gpu)
908 {
909 	struct ttm_bo_global *glob = bdev->glob;
910 	struct ttm_mem_type_manager *man = &bdev->man[mem_type];
911 	struct ttm_buffer_object *bo;
912 	int ret = -EBUSY, put_count;
913 
914 	lockmgr(&glob->lru_lock, LK_EXCLUSIVE);
915 	list_for_each_entry(bo, &man->lru, lru) {
916 		ret = ttm_bo_reserve_nolru(bo, false, true, false, 0);
917 		if (!ret)
918 			break;
919 	}
920 
921 	if (ret) {
922 		lockmgr(&glob->lru_lock, LK_RELEASE);
923 		return ret;
924 	}
925 
926 	kref_get(&bo->list_kref);
927 
928 	if (!list_empty(&bo->ddestroy)) {
929 		ret = ttm_bo_cleanup_refs_and_unlock(bo, interruptible,
930 						     no_wait_gpu);
931 		kref_put(&bo->list_kref, ttm_bo_release_list);
932 		return ret;
933 	}
934 
935 	put_count = ttm_bo_del_from_lru(bo);
936 	lockmgr(&glob->lru_lock, LK_RELEASE);
937 
938 	BUG_ON(ret != 0);
939 
940 	ttm_bo_list_ref_sub(bo, put_count, true);
941 
942 	ret = ttm_bo_evict(bo, interruptible, no_wait_gpu);
943 	ttm_bo_unreserve(bo);
944 
945 	kref_put(&bo->list_kref, ttm_bo_release_list);
946 	return ret;
947 }
948 
949 void ttm_bo_mem_put(struct ttm_buffer_object *bo, struct ttm_mem_reg *mem)
950 {
951 	struct ttm_mem_type_manager *man = &bo->bdev->man[mem->mem_type];
952 
953 	if (mem->mm_node)
954 		(*man->func->put_node)(man, mem);
955 }
956 EXPORT_SYMBOL(ttm_bo_mem_put);
957 
958 /**
959  * Repeatedly evict memory from the LRU for @mem_type until we create enough
960  * space, or we've evicted everything and there isn't enough space.
961  */
962 static int ttm_bo_mem_force_space(struct ttm_buffer_object *bo,
963 					uint32_t mem_type,
964 					struct ttm_placement *placement,
965 					struct ttm_mem_reg *mem,
966 					bool interruptible,
967 					bool no_wait_gpu)
968 {
969 	struct ttm_bo_device *bdev = bo->bdev;
970 	struct ttm_mem_type_manager *man = &bdev->man[mem_type];
971 	int ret;
972 
973 	do {
974 		ret = (*man->func->get_node)(man, bo, placement, 0, mem);
975 		if (unlikely(ret != 0))
976 			return ret;
977 		if (mem->mm_node)
978 			break;
979 		ret = ttm_mem_evict_first(bdev, mem_type,
980 					  interruptible, no_wait_gpu);
981 		if (unlikely(ret != 0))
982 			return ret;
983 	} while (1);
984 	if (mem->mm_node == NULL)
985 		return -ENOMEM;
986 	mem->mem_type = mem_type;
987 	return 0;
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 				 uint32_t proposed_placement,
1018 				 uint32_t *masked_placement)
1019 {
1020 	uint32_t cur_flags = ttm_bo_type_flags(mem_type);
1021 
1022 	if ((cur_flags & proposed_placement & TTM_PL_MASK_MEM) == 0)
1023 		return false;
1024 
1025 	if ((proposed_placement & man->available_caching) == 0)
1026 		return false;
1027 
1028 	cur_flags |= (proposed_placement & man->available_caching);
1029 
1030 	*masked_placement = cur_flags;
1031 	return true;
1032 }
1033 
1034 /**
1035  * Creates space for memory region @mem according to its type.
1036  *
1037  * This function first searches for free space in compatible memory types in
1038  * the priority order defined by the driver.  If free space isn't found, then
1039  * ttm_bo_mem_force_space is attempted in priority order to evict and find
1040  * space.
1041  */
1042 int ttm_bo_mem_space(struct ttm_buffer_object *bo,
1043 			struct ttm_placement *placement,
1044 			struct ttm_mem_reg *mem,
1045 			bool interruptible,
1046 			bool no_wait_gpu)
1047 {
1048 	struct ttm_bo_device *bdev = bo->bdev;
1049 	struct ttm_mem_type_manager *man;
1050 	uint32_t mem_type = TTM_PL_SYSTEM;
1051 	uint32_t cur_flags = 0;
1052 	bool type_found = false;
1053 	bool type_ok = false;
1054 	bool has_erestartsys = false;
1055 	int i, ret;
1056 
1057 	mem->mm_node = NULL;
1058 	for (i = 0; i < placement->num_placement; ++i) {
1059 		ret = ttm_mem_type_from_flags(placement->placement[i],
1060 						&mem_type);
1061 		if (ret)
1062 			return ret;
1063 		man = &bdev->man[mem_type];
1064 
1065 		type_ok = ttm_bo_mt_compatible(man,
1066 						mem_type,
1067 						placement->placement[i],
1068 						&cur_flags);
1069 
1070 		if (!type_ok)
1071 			continue;
1072 
1073 		cur_flags = ttm_bo_select_caching(man, bo->mem.placement,
1074 						  cur_flags);
1075 		/*
1076 		 * Use the access and other non-mapping-related flag bits from
1077 		 * the memory placement flags to the current flags
1078 		 */
1079 		ttm_flag_masked(&cur_flags, placement->placement[i],
1080 				~TTM_PL_MASK_MEMTYPE);
1081 
1082 		if (mem_type == TTM_PL_SYSTEM)
1083 			break;
1084 
1085 		if (man->has_type && man->use_type) {
1086 			type_found = true;
1087 			ret = (*man->func->get_node)(man, bo, placement,
1088 						     cur_flags, mem);
1089 			if (unlikely(ret))
1090 				return ret;
1091 		}
1092 		if (mem->mm_node)
1093 			break;
1094 	}
1095 
1096 	if ((type_ok && (mem_type == TTM_PL_SYSTEM)) || mem->mm_node) {
1097 		mem->mem_type = mem_type;
1098 		mem->placement = cur_flags;
1099 		return 0;
1100 	}
1101 
1102 	if (!type_found)
1103 		return -EINVAL;
1104 
1105 	for (i = 0; i < placement->num_busy_placement; ++i) {
1106 		ret = ttm_mem_type_from_flags(placement->busy_placement[i],
1107 						&mem_type);
1108 		if (ret)
1109 			return ret;
1110 		man = &bdev->man[mem_type];
1111 		if (!man->has_type)
1112 			continue;
1113 		if (!ttm_bo_mt_compatible(man,
1114 						mem_type,
1115 						placement->busy_placement[i],
1116 						&cur_flags))
1117 			continue;
1118 
1119 		cur_flags = ttm_bo_select_caching(man, bo->mem.placement,
1120 						  cur_flags);
1121 		/*
1122 		 * Use the access and other non-mapping-related flag bits from
1123 		 * the memory placement flags to the current flags
1124 		 */
1125 		ttm_flag_masked(&cur_flags, placement->busy_placement[i],
1126 				~TTM_PL_MASK_MEMTYPE);
1127 
1128 		if (mem_type == TTM_PL_SYSTEM) {
1129 			mem->mem_type = mem_type;
1130 			mem->placement = cur_flags;
1131 			mem->mm_node = NULL;
1132 			return 0;
1133 		}
1134 
1135 		ret = ttm_bo_mem_force_space(bo, mem_type, placement, mem,
1136 						interruptible, no_wait_gpu);
1137 		if (ret == 0 && mem->mm_node) {
1138 			mem->placement = cur_flags;
1139 			return 0;
1140 		}
1141 		if (ret == -ERESTARTSYS)
1142 			has_erestartsys = true;
1143 	}
1144 	ret = (has_erestartsys) ? -ERESTARTSYS : -ENOMEM;
1145 	return ret;
1146 }
1147 EXPORT_SYMBOL(ttm_bo_mem_space);
1148 
1149 static int ttm_bo_move_buffer(struct ttm_buffer_object *bo,
1150 			struct ttm_placement *placement,
1151 			bool interruptible,
1152 			bool no_wait_gpu)
1153 {
1154 	int ret = 0;
1155 	struct ttm_mem_reg mem;
1156 	struct ttm_bo_device *bdev = bo->bdev;
1157 
1158 	BUG_ON(!ttm_bo_is_reserved(bo));
1159 
1160 	/*
1161 	 * FIXME: It's possible to pipeline buffer moves.
1162 	 * Have the driver move function wait for idle when necessary,
1163 	 * instead of doing it here.
1164 	 */
1165 	lockmgr(&bdev->fence_lock, LK_EXCLUSIVE);
1166 	ret = ttm_bo_wait(bo, false, interruptible, no_wait_gpu);
1167 	lockmgr(&bdev->fence_lock, LK_RELEASE);
1168 	if (ret)
1169 		return ret;
1170 	mem.num_pages = bo->num_pages;
1171 	mem.size = mem.num_pages << PAGE_SHIFT;
1172 	mem.page_alignment = bo->mem.page_alignment;
1173 	mem.bus.io_reserved_vm = false;
1174 	mem.bus.io_reserved_count = 0;
1175 	/*
1176 	 * Determine where to move the buffer.
1177 	 */
1178 	ret = ttm_bo_mem_space(bo, placement, &mem,
1179 			       interruptible, no_wait_gpu);
1180 	if (ret)
1181 		goto out_unlock;
1182 	ret = ttm_bo_handle_move_mem(bo, &mem, false,
1183 				     interruptible, no_wait_gpu);
1184 out_unlock:
1185 	if (ret && mem.mm_node)
1186 		ttm_bo_mem_put(bo, &mem);
1187 	return ret;
1188 }
1189 
1190 static bool ttm_bo_mem_compat(struct ttm_placement *placement,
1191 			      struct ttm_mem_reg *mem,
1192 			      uint32_t *new_flags)
1193 {
1194 	int i;
1195 
1196 	if (mem->mm_node && placement->lpfn != 0 &&
1197 	    (mem->start < placement->fpfn ||
1198 	     mem->start + mem->num_pages > placement->lpfn))
1199 		return false;
1200 
1201 	for (i = 0; i < placement->num_placement; i++) {
1202 		*new_flags = placement->placement[i];
1203 		if ((*new_flags & mem->placement & TTM_PL_MASK_CACHING) &&
1204 		    (*new_flags & mem->placement & TTM_PL_MASK_MEM))
1205 			return true;
1206 	}
1207 
1208 	for (i = 0; i < placement->num_busy_placement; i++) {
1209 		*new_flags = placement->busy_placement[i];
1210 		if ((*new_flags & mem->placement & TTM_PL_MASK_CACHING) &&
1211 		    (*new_flags & mem->placement & TTM_PL_MASK_MEM))
1212 			return true;
1213 	}
1214 
1215 	return false;
1216 }
1217 
1218 int ttm_bo_validate(struct ttm_buffer_object *bo,
1219 			struct ttm_placement *placement,
1220 			bool interruptible,
1221 			bool no_wait_gpu)
1222 {
1223 	int ret;
1224 	uint32_t new_flags;
1225 
1226 	BUG_ON(!ttm_bo_is_reserved(bo));
1227 	/* Check that range is valid */
1228 	if (placement->lpfn || placement->fpfn)
1229 		if (placement->fpfn > placement->lpfn ||
1230 			(placement->lpfn - placement->fpfn) < bo->num_pages)
1231 			return -EINVAL;
1232 	/*
1233 	 * Check whether we need to move buffer.
1234 	 */
1235 	if (!ttm_bo_mem_compat(placement, &bo->mem, &new_flags)) {
1236 		ret = ttm_bo_move_buffer(bo, placement, interruptible,
1237 					 no_wait_gpu);
1238 		if (ret)
1239 			return ret;
1240 	} else {
1241 		/*
1242 		 * Use the access and other non-mapping-related flag bits from
1243 		 * the compatible memory placement flags to the active flags
1244 		 */
1245 		ttm_flag_masked(&bo->mem.placement, new_flags,
1246 				~TTM_PL_MASK_MEMTYPE);
1247 	}
1248 	/*
1249 	 * We might need to add a TTM.
1250 	 */
1251 	if (bo->mem.mem_type == TTM_PL_SYSTEM && bo->ttm == NULL) {
1252 		ret = ttm_bo_add_ttm(bo, true);
1253 		if (ret)
1254 			return ret;
1255 	}
1256 	return 0;
1257 }
1258 EXPORT_SYMBOL(ttm_bo_validate);
1259 
1260 int ttm_bo_check_placement(struct ttm_buffer_object *bo,
1261 				struct ttm_placement *placement)
1262 {
1263 	BUG_ON((placement->fpfn || placement->lpfn) &&
1264 	       (bo->mem.num_pages > (placement->lpfn - placement->fpfn)));
1265 
1266 	return 0;
1267 }
1268 
1269 int ttm_bo_init(struct ttm_bo_device *bdev,
1270 		struct ttm_buffer_object *bo,
1271 		unsigned long size,
1272 		enum ttm_bo_type type,
1273 		struct ttm_placement *placement,
1274 		uint32_t page_alignment,
1275 		bool interruptible,
1276 		struct vm_object *persistent_swap_storage,
1277 		size_t acc_size,
1278 		struct sg_table *sg,
1279 		void (*destroy) (struct ttm_buffer_object *))
1280 {
1281 	int ret = 0;
1282 	unsigned long num_pages;
1283 	struct ttm_mem_global *mem_glob = bdev->glob->mem_glob;
1284 
1285 	ret = ttm_mem_global_alloc(mem_glob, acc_size, false, false);
1286 	if (ret) {
1287 		kprintf("[TTM] Out of kernel memory\n");
1288 		if (destroy)
1289 			(*destroy)(bo);
1290 		else
1291 			kfree(bo);
1292 		return -ENOMEM;
1293 	}
1294 
1295 	num_pages = (size + PAGE_SIZE - 1) >> PAGE_SHIFT;
1296 	if (num_pages == 0) {
1297 		kprintf("[TTM] Illegal buffer object size\n");
1298 		if (destroy)
1299 			(*destroy)(bo);
1300 		else
1301 			kfree(bo);
1302 		ttm_mem_global_free(mem_glob, acc_size);
1303 		return -EINVAL;
1304 	}
1305 	bo->destroy = destroy;
1306 
1307 	kref_init(&bo->kref);
1308 	kref_init(&bo->list_kref);
1309 	atomic_set(&bo->cpu_writers, 0);
1310 	atomic_set(&bo->reserved, 1);
1311 	init_waitqueue_head(&bo->event_queue);
1312 	INIT_LIST_HEAD(&bo->lru);
1313 	INIT_LIST_HEAD(&bo->ddestroy);
1314 	INIT_LIST_HEAD(&bo->swap);
1315 	INIT_LIST_HEAD(&bo->io_reserve_lru);
1316 	/*bzero(&bo->vm_rb, sizeof(bo->vm_rb));*/
1317 	bo->bdev = bdev;
1318 	bo->glob = bdev->glob;
1319 	bo->type = type;
1320 	bo->num_pages = num_pages;
1321 	bo->mem.size = num_pages << PAGE_SHIFT;
1322 	bo->mem.mem_type = TTM_PL_SYSTEM;
1323 	bo->mem.num_pages = bo->num_pages;
1324 	bo->mem.mm_node = NULL;
1325 	bo->mem.page_alignment = page_alignment;
1326 	bo->mem.bus.io_reserved_vm = false;
1327 	bo->mem.bus.io_reserved_count = 0;
1328 	bo->priv_flags = 0;
1329 	bo->mem.placement = (TTM_PL_FLAG_SYSTEM | TTM_PL_FLAG_CACHED);
1330 	bo->seq_valid = false;
1331 	bo->persistent_swap_storage = persistent_swap_storage;
1332 	bo->acc_size = acc_size;
1333 	bo->sg = sg;
1334 	atomic_inc(&bo->glob->bo_count);
1335 
1336 	/*
1337 	 * Mirror ref from kref_init() for list_kref.
1338 	 */
1339 	set_bit(TTM_BO_PRIV_FLAG_ACTIVE, &bo->priv_flags);
1340 
1341 	ret = ttm_bo_check_placement(bo, placement);
1342 	if (unlikely(ret != 0))
1343 		goto out_err;
1344 
1345 	/*
1346 	 * For ttm_bo_type_device buffers, allocate
1347 	 * address space from the device.
1348 	 */
1349 	if (bo->type == ttm_bo_type_device ||
1350 	    bo->type == ttm_bo_type_sg) {
1351 		ret = ttm_bo_setup_vm(bo);
1352 		if (ret)
1353 			goto out_err;
1354 	}
1355 
1356 	ret = ttm_bo_validate(bo, placement, interruptible, false);
1357 	if (ret)
1358 		goto out_err;
1359 
1360 	ttm_bo_unreserve(bo);
1361 	return 0;
1362 
1363 out_err:
1364 	ttm_bo_unreserve(bo);
1365 	ttm_bo_unref(&bo);
1366 
1367 	return ret;
1368 }
1369 EXPORT_SYMBOL(ttm_bo_init);
1370 
1371 size_t ttm_bo_acc_size(struct ttm_bo_device *bdev,
1372 		       unsigned long bo_size,
1373 		       unsigned struct_size)
1374 {
1375 	unsigned npages = (PAGE_ALIGN(bo_size)) >> PAGE_SHIFT;
1376 	size_t size = 0;
1377 
1378 	size += ttm_round_pot(struct_size);
1379 	size += PAGE_ALIGN(npages * sizeof(void *));
1380 	size += ttm_round_pot(sizeof(struct ttm_tt));
1381 	return size;
1382 }
1383 EXPORT_SYMBOL(ttm_bo_acc_size);
1384 
1385 size_t ttm_bo_dma_acc_size(struct ttm_bo_device *bdev,
1386 			   unsigned long bo_size,
1387 			   unsigned struct_size)
1388 {
1389 	unsigned npages = (PAGE_ALIGN(bo_size)) >> PAGE_SHIFT;
1390 	size_t size = 0;
1391 
1392 	size += ttm_round_pot(struct_size);
1393 	size += PAGE_ALIGN(npages * sizeof(void *));
1394 	size += PAGE_ALIGN(npages * sizeof(dma_addr_t));
1395 	size += ttm_round_pot(sizeof(struct ttm_dma_tt));
1396 	return size;
1397 }
1398 EXPORT_SYMBOL(ttm_bo_dma_acc_size);
1399 
1400 int ttm_bo_create(struct ttm_bo_device *bdev,
1401 			unsigned long size,
1402 			enum ttm_bo_type type,
1403 			struct ttm_placement *placement,
1404 			uint32_t page_alignment,
1405 			bool interruptible,
1406 			struct vm_object *persistent_swap_storage,
1407 			struct ttm_buffer_object **p_bo)
1408 {
1409 	struct ttm_buffer_object *bo;
1410 	size_t acc_size;
1411 	int ret;
1412 
1413 	*p_bo = NULL;
1414 	bo = kmalloc(sizeof(*bo), M_DRM, M_WAITOK | M_ZERO);
1415 	if (unlikely(bo == NULL))
1416 		return -ENOMEM;
1417 
1418 	acc_size = ttm_bo_acc_size(bdev, size, sizeof(struct ttm_buffer_object));
1419 	ret = ttm_bo_init(bdev, bo, size, type, placement, page_alignment,
1420 			  interruptible, persistent_swap_storage, acc_size,
1421 			  NULL, NULL);
1422 	if (likely(ret == 0))
1423 		*p_bo = bo;
1424 
1425 	return ret;
1426 }
1427 EXPORT_SYMBOL(ttm_bo_create);
1428 
1429 static int ttm_bo_force_list_clean(struct ttm_bo_device *bdev,
1430 					unsigned mem_type, bool allow_errors)
1431 {
1432 	struct ttm_mem_type_manager *man = &bdev->man[mem_type];
1433 	struct ttm_bo_global *glob = bdev->glob;
1434 	int ret;
1435 
1436 	/*
1437 	 * Can't use standard list traversal since we're unlocking.
1438 	 */
1439 
1440 	lockmgr(&glob->lru_lock, LK_EXCLUSIVE);
1441 	while (!list_empty(&man->lru)) {
1442 		lockmgr(&glob->lru_lock, LK_RELEASE);
1443 		ret = ttm_mem_evict_first(bdev, mem_type, false, false);
1444 		if (ret) {
1445 			if (allow_errors) {
1446 				return ret;
1447 			} else {
1448 				kprintf("[TTM] Cleanup eviction failed\n");
1449 			}
1450 		}
1451 		lockmgr(&glob->lru_lock, LK_EXCLUSIVE);
1452 	}
1453 	lockmgr(&glob->lru_lock, LK_RELEASE);
1454 	return 0;
1455 }
1456 
1457 int ttm_bo_clean_mm(struct ttm_bo_device *bdev, unsigned mem_type)
1458 {
1459 	struct ttm_mem_type_manager *man;
1460 	int ret = -EINVAL;
1461 
1462 	if (mem_type >= TTM_NUM_MEM_TYPES) {
1463 		kprintf("[TTM] Illegal memory type %d\n", mem_type);
1464 		return ret;
1465 	}
1466 	man = &bdev->man[mem_type];
1467 
1468 	if (!man->has_type) {
1469 		kprintf("[TTM] Trying to take down uninitialized memory manager type %u\n",
1470 		       mem_type);
1471 		return ret;
1472 	}
1473 
1474 	man->use_type = false;
1475 	man->has_type = false;
1476 
1477 	ret = 0;
1478 	if (mem_type > 0) {
1479 		ttm_bo_force_list_clean(bdev, mem_type, false);
1480 
1481 		ret = (*man->func->takedown)(man);
1482 	}
1483 
1484 	return ret;
1485 }
1486 EXPORT_SYMBOL(ttm_bo_clean_mm);
1487 
1488 int ttm_bo_evict_mm(struct ttm_bo_device *bdev, unsigned mem_type)
1489 {
1490 	struct ttm_mem_type_manager *man = &bdev->man[mem_type];
1491 
1492 	if (mem_type == 0 || mem_type >= TTM_NUM_MEM_TYPES) {
1493 		kprintf("[TTM] Illegal memory manager memory type %u\n", mem_type);
1494 		return -EINVAL;
1495 	}
1496 
1497 	if (!man->has_type) {
1498 		kprintf("[TTM] Memory type %u has not been initialized\n", mem_type);
1499 		return 0;
1500 	}
1501 
1502 	return ttm_bo_force_list_clean(bdev, mem_type, true);
1503 }
1504 EXPORT_SYMBOL(ttm_bo_evict_mm);
1505 
1506 int ttm_bo_init_mm(struct ttm_bo_device *bdev, unsigned type,
1507 			unsigned long p_size)
1508 {
1509 	int ret = -EINVAL;
1510 	struct ttm_mem_type_manager *man;
1511 
1512 	BUG_ON(type >= TTM_NUM_MEM_TYPES);
1513 	man = &bdev->man[type];
1514 	BUG_ON(man->has_type);
1515 	man->io_reserve_fastpath = true;
1516 	man->use_io_reserve_lru = false;
1517 	lockinit(&man->io_reserve_mutex, "ttmman", 0, LK_CANRECURSE);
1518 	INIT_LIST_HEAD(&man->io_reserve_lru);
1519 
1520 	ret = bdev->driver->init_mem_type(bdev, type, man);
1521 	if (ret)
1522 		return ret;
1523 	man->bdev = bdev;
1524 
1525 	ret = 0;
1526 	if (type != TTM_PL_SYSTEM) {
1527 		ret = (*man->func->init)(man, p_size);
1528 		if (ret)
1529 			return ret;
1530 	}
1531 	man->has_type = true;
1532 	man->use_type = true;
1533 	man->size = p_size;
1534 
1535 	INIT_LIST_HEAD(&man->lru);
1536 
1537 	return 0;
1538 }
1539 EXPORT_SYMBOL(ttm_bo_init_mm);
1540 
1541 static void ttm_bo_global_kobj_release(struct ttm_bo_global *glob)
1542 {
1543 	ttm_mem_unregister_shrink(glob->mem_glob, &glob->shrink);
1544 	vm_page_free_contig(glob->dummy_read_page, PAGE_SIZE);
1545 	glob->dummy_read_page = NULL;
1546 	/*
1547 	vm_page_free(glob->dummy_read_page);
1548 	*/
1549 }
1550 
1551 void ttm_bo_global_release(struct drm_global_reference *ref)
1552 {
1553 	struct ttm_bo_global *glob = ref->object;
1554 
1555 	if (refcount_release(&glob->kobj_ref))
1556 		ttm_bo_global_kobj_release(glob);
1557 }
1558 EXPORT_SYMBOL(ttm_bo_global_release);
1559 
1560 int ttm_bo_global_init(struct drm_global_reference *ref)
1561 {
1562 	struct ttm_bo_global_ref *bo_ref =
1563 		container_of(ref, struct ttm_bo_global_ref, ref);
1564 	struct ttm_bo_global *glob = ref->object;
1565 	int ret;
1566 
1567 	lockinit(&glob->device_list_mutex, "ttmdlm", 0, LK_CANRECURSE);
1568 	lockinit(&glob->lru_lock, "ttmlru", 0, LK_CANRECURSE);
1569 	glob->mem_glob = bo_ref->mem_glob;
1570 	glob->dummy_read_page = vm_page_alloc_contig(
1571 	    0, VM_MAX_ADDRESS, PAGE_SIZE, 0, 1*PAGE_SIZE, VM_MEMATTR_UNCACHEABLE);
1572 
1573 	if (unlikely(glob->dummy_read_page == NULL)) {
1574 		ret = -ENOMEM;
1575 		goto out_no_drp;
1576 	}
1577 
1578 	INIT_LIST_HEAD(&glob->swap_lru);
1579 	INIT_LIST_HEAD(&glob->device_list);
1580 
1581 	ttm_mem_init_shrink(&glob->shrink, ttm_bo_swapout);
1582 	ret = ttm_mem_register_shrink(glob->mem_glob, &glob->shrink);
1583 	if (unlikely(ret != 0)) {
1584 		kprintf("[TTM] Could not register buffer object swapout\n");
1585 		goto out_no_shrink;
1586 	}
1587 
1588 	atomic_set(&glob->bo_count, 0);
1589 
1590 	refcount_init(&glob->kobj_ref, 1);
1591 	return (0);
1592 
1593 out_no_shrink:
1594 	vm_page_free_contig(glob->dummy_read_page, PAGE_SIZE);
1595 	glob->dummy_read_page = NULL;
1596 	/*
1597 	vm_page_free(glob->dummy_read_page);
1598 	*/
1599 out_no_drp:
1600 	kfree(glob);
1601 	return ret;
1602 }
1603 EXPORT_SYMBOL(ttm_bo_global_init);
1604 
1605 
1606 int ttm_bo_device_release(struct ttm_bo_device *bdev)
1607 {
1608 	int ret = 0;
1609 	unsigned i = TTM_NUM_MEM_TYPES;
1610 	struct ttm_mem_type_manager *man;
1611 	struct ttm_bo_global *glob = bdev->glob;
1612 
1613 	while (i--) {
1614 		man = &bdev->man[i];
1615 		if (man->has_type) {
1616 			man->use_type = false;
1617 			if ((i != TTM_PL_SYSTEM) && ttm_bo_clean_mm(bdev, i)) {
1618 				ret = -EBUSY;
1619 				kprintf("[TTM] DRM memory manager type %d is not clean\n",
1620 				       i);
1621 			}
1622 			man->has_type = false;
1623 		}
1624 	}
1625 
1626 	lockmgr(&glob->device_list_mutex, LK_EXCLUSIVE);
1627 	list_del(&bdev->device_list);
1628 	lockmgr(&glob->device_list_mutex, LK_RELEASE);
1629 
1630 	cancel_delayed_work_sync(&bdev->wq);
1631 
1632 	while (ttm_bo_delayed_delete(bdev, true))
1633 		;
1634 
1635 	lockmgr(&glob->lru_lock, LK_EXCLUSIVE);
1636 	if (list_empty(&bdev->ddestroy))
1637 		TTM_DEBUG("Delayed destroy list was clean\n");
1638 
1639 	if (list_empty(&bdev->man[0].lru))
1640 		TTM_DEBUG("Swap list was clean\n");
1641 	lockmgr(&glob->lru_lock, LK_RELEASE);
1642 
1643 	BUG_ON(!drm_mm_clean(&bdev->addr_space_mm));
1644 	lockmgr(&bdev->vm_lock, LK_EXCLUSIVE);
1645 	drm_mm_takedown(&bdev->addr_space_mm);
1646 	lockmgr(&bdev->vm_lock, LK_RELEASE);
1647 
1648 	return ret;
1649 }
1650 EXPORT_SYMBOL(ttm_bo_device_release);
1651 
1652 int ttm_bo_device_init(struct ttm_bo_device *bdev,
1653 		       struct ttm_bo_global *glob,
1654 		       struct ttm_bo_driver *driver,
1655 		       uint64_t file_page_offset,
1656 		       bool need_dma32)
1657 {
1658 	int ret = -EINVAL;
1659 
1660 	lockinit(&bdev->vm_lock, "ttmvml", 0, LK_CANRECURSE);
1661 	bdev->driver = driver;
1662 
1663 	memset(bdev->man, 0, sizeof(bdev->man));
1664 
1665 	/*
1666 	 * Initialize the system memory buffer type.
1667 	 * Other types need to be driver / IOCTL initialized.
1668 	 */
1669 	ret = ttm_bo_init_mm(bdev, TTM_PL_SYSTEM, 0);
1670 	if (unlikely(ret != 0))
1671 		goto out_no_sys;
1672 
1673 	RB_INIT(&bdev->addr_space_rb);
1674 	drm_mm_init(&bdev->addr_space_mm, file_page_offset, 0x10000000);
1675 
1676 	INIT_DELAYED_WORK(&bdev->wq, ttm_bo_delayed_workqueue);
1677 	INIT_LIST_HEAD(&bdev->ddestroy);
1678 	bdev->dev_mapping = NULL;
1679 	bdev->glob = glob;
1680 	bdev->need_dma32 = need_dma32;
1681 	bdev->val_seq = 0;
1682 	lockinit(&bdev->fence_lock, "ttmfence", 0, LK_CANRECURSE);
1683 	lockmgr(&glob->device_list_mutex, LK_EXCLUSIVE);
1684 	list_add_tail(&bdev->device_list, &glob->device_list);
1685 	lockmgr(&glob->device_list_mutex, LK_RELEASE);
1686 
1687 	return 0;
1688 out_no_sys:
1689 	return ret;
1690 }
1691 EXPORT_SYMBOL(ttm_bo_device_init);
1692 
1693 /*
1694  * buffer object vm functions.
1695  */
1696 
1697 bool ttm_mem_reg_is_pci(struct ttm_bo_device *bdev, struct ttm_mem_reg *mem)
1698 {
1699 	struct ttm_mem_type_manager *man = &bdev->man[mem->mem_type];
1700 
1701 	if (!(man->flags & TTM_MEMTYPE_FLAG_FIXED)) {
1702 		if (mem->mem_type == TTM_PL_SYSTEM)
1703 			return false;
1704 
1705 		if (man->flags & TTM_MEMTYPE_FLAG_CMA)
1706 			return false;
1707 
1708 		if (mem->placement & TTM_PL_FLAG_CACHED)
1709 			return false;
1710 	}
1711 	return true;
1712 }
1713 
1714 void ttm_bo_unmap_virtual_locked(struct ttm_buffer_object *bo)
1715 {
1716 
1717 	ttm_bo_release_mmap(bo);
1718 	ttm_mem_io_free_vm(bo);
1719 }
1720 
1721 void ttm_bo_unmap_virtual(struct ttm_buffer_object *bo)
1722 {
1723 	struct ttm_bo_device *bdev = bo->bdev;
1724 	struct ttm_mem_type_manager *man = &bdev->man[bo->mem.mem_type];
1725 
1726 	ttm_mem_io_lock(man, false);
1727 	ttm_bo_unmap_virtual_locked(bo);
1728 	ttm_mem_io_unlock(man);
1729 }
1730 
1731 
1732 EXPORT_SYMBOL(ttm_bo_unmap_virtual);
1733 
1734 static void ttm_bo_vm_insert_rb(struct ttm_buffer_object *bo)
1735 {
1736 	struct ttm_bo_device *bdev = bo->bdev;
1737 
1738 	/* The caller acquired bdev->vm_lock. */
1739 	RB_INSERT(ttm_bo_device_buffer_objects, &bdev->addr_space_rb, bo);
1740 }
1741 
1742 /**
1743  * ttm_bo_setup_vm:
1744  *
1745  * @bo: the buffer to allocate address space for
1746  *
1747  * Allocate address space in the drm device so that applications
1748  * can mmap the buffer and access the contents. This only
1749  * applies to ttm_bo_type_device objects as others are not
1750  * placed in the drm device address space.
1751  */
1752 
1753 static int ttm_bo_setup_vm(struct ttm_buffer_object *bo)
1754 {
1755 	struct ttm_bo_device *bdev = bo->bdev;
1756 	int ret;
1757 
1758 retry_pre_get:
1759 	ret = drm_mm_pre_get(&bdev->addr_space_mm);
1760 	if (unlikely(ret != 0))
1761 		return ret;
1762 
1763 	lockmgr(&bdev->vm_lock, LK_EXCLUSIVE);
1764 	bo->vm_node = drm_mm_search_free(&bdev->addr_space_mm,
1765 					 bo->mem.num_pages, 0, 0);
1766 
1767 	if (unlikely(bo->vm_node == NULL)) {
1768 		ret = -ENOMEM;
1769 		goto out_unlock;
1770 	}
1771 
1772 	bo->vm_node = drm_mm_get_block_atomic(bo->vm_node,
1773 					      bo->mem.num_pages, 0);
1774 
1775 	if (unlikely(bo->vm_node == NULL)) {
1776 		lockmgr(&bdev->vm_lock, LK_RELEASE);
1777 		goto retry_pre_get;
1778 	}
1779 
1780 	ttm_bo_vm_insert_rb(bo);
1781 	lockmgr(&bdev->vm_lock, LK_RELEASE);
1782 	bo->addr_space_offset = ((uint64_t) bo->vm_node->start) << PAGE_SHIFT;
1783 
1784 	return 0;
1785 out_unlock:
1786 	lockmgr(&bdev->vm_lock, LK_RELEASE);
1787 	return ret;
1788 }
1789 
1790 int ttm_bo_wait(struct ttm_buffer_object *bo,
1791 		bool lazy, bool interruptible, bool no_wait)
1792 {
1793 	struct ttm_bo_driver *driver = bo->bdev->driver;
1794 	struct ttm_bo_device *bdev = bo->bdev;
1795 	void *sync_obj;
1796 	int ret = 0;
1797 
1798 	if (likely(bo->sync_obj == NULL))
1799 		return 0;
1800 
1801 	while (bo->sync_obj) {
1802 
1803 		if (driver->sync_obj_signaled(bo->sync_obj)) {
1804 			void *tmp_obj = bo->sync_obj;
1805 			bo->sync_obj = NULL;
1806 			clear_bit(TTM_BO_PRIV_FLAG_MOVING, &bo->priv_flags);
1807 			lockmgr(&bdev->fence_lock, LK_RELEASE);
1808 			driver->sync_obj_unref(&tmp_obj);
1809 			lockmgr(&bdev->fence_lock, LK_EXCLUSIVE);
1810 			continue;
1811 		}
1812 
1813 		if (no_wait)
1814 			return -EBUSY;
1815 
1816 		sync_obj = driver->sync_obj_ref(bo->sync_obj);
1817 		lockmgr(&bdev->fence_lock, LK_RELEASE);
1818 		ret = driver->sync_obj_wait(sync_obj,
1819 					    lazy, interruptible);
1820 		if (unlikely(ret != 0)) {
1821 			driver->sync_obj_unref(&sync_obj);
1822 			lockmgr(&bdev->fence_lock, LK_EXCLUSIVE);
1823 			return ret;
1824 		}
1825 		lockmgr(&bdev->fence_lock, LK_EXCLUSIVE);
1826 		if (likely(bo->sync_obj == sync_obj)) {
1827 			void *tmp_obj = bo->sync_obj;
1828 			bo->sync_obj = NULL;
1829 			clear_bit(TTM_BO_PRIV_FLAG_MOVING,
1830 				  &bo->priv_flags);
1831 			lockmgr(&bdev->fence_lock, LK_RELEASE);
1832 			driver->sync_obj_unref(&sync_obj);
1833 			driver->sync_obj_unref(&tmp_obj);
1834 			lockmgr(&bdev->fence_lock, LK_EXCLUSIVE);
1835 		} else {
1836 			lockmgr(&bdev->fence_lock, LK_RELEASE);
1837 			driver->sync_obj_unref(&sync_obj);
1838 			lockmgr(&bdev->fence_lock, LK_EXCLUSIVE);
1839 		}
1840 	}
1841 	return 0;
1842 }
1843 EXPORT_SYMBOL(ttm_bo_wait);
1844 
1845 int ttm_bo_synccpu_write_grab(struct ttm_buffer_object *bo, bool no_wait)
1846 {
1847 	struct ttm_bo_device *bdev = bo->bdev;
1848 	int ret = 0;
1849 
1850 	/*
1851 	 * Using ttm_bo_reserve makes sure the lru lists are updated.
1852 	 */
1853 
1854 	ret = ttm_bo_reserve(bo, true, no_wait, false, 0);
1855 	if (unlikely(ret != 0))
1856 		return ret;
1857 	lockmgr(&bdev->fence_lock, LK_EXCLUSIVE);
1858 	ret = ttm_bo_wait(bo, false, true, no_wait);
1859 	lockmgr(&bdev->fence_lock, LK_RELEASE);
1860 	if (likely(ret == 0))
1861 		atomic_inc(&bo->cpu_writers);
1862 	ttm_bo_unreserve(bo);
1863 	return ret;
1864 }
1865 EXPORT_SYMBOL(ttm_bo_synccpu_write_grab);
1866 
1867 void ttm_bo_synccpu_write_release(struct ttm_buffer_object *bo)
1868 {
1869 	atomic_dec(&bo->cpu_writers);
1870 }
1871 EXPORT_SYMBOL(ttm_bo_synccpu_write_release);
1872 
1873 /**
1874  * A buffer object shrink method that tries to swap out the first
1875  * buffer object on the bo_global::swap_lru list.
1876  */
1877 
1878 static int ttm_bo_swapout(struct ttm_mem_shrink *shrink)
1879 {
1880 	struct ttm_bo_global *glob =
1881 	    container_of(shrink, struct ttm_bo_global, shrink);
1882 	struct ttm_buffer_object *bo;
1883 	int ret = -EBUSY;
1884 	int put_count;
1885 	uint32_t swap_placement = (TTM_PL_FLAG_CACHED | TTM_PL_FLAG_SYSTEM);
1886 
1887 	lockmgr(&glob->lru_lock, LK_EXCLUSIVE);
1888 	list_for_each_entry(bo, &glob->swap_lru, swap) {
1889 		ret = ttm_bo_reserve_nolru(bo, false, true, false, 0);
1890 		if (!ret)
1891 			break;
1892 	}
1893 
1894 	if (ret) {
1895 		lockmgr(&glob->lru_lock, LK_RELEASE);
1896 		return ret;
1897 	}
1898 
1899 	kref_get(&bo->list_kref);
1900 
1901 	if (!list_empty(&bo->ddestroy)) {
1902 		ret = ttm_bo_cleanup_refs_and_unlock(bo, false, false);
1903 		kref_put(&bo->list_kref, ttm_bo_release_list);
1904 		return ret;
1905 	}
1906 
1907 	put_count = ttm_bo_del_from_lru(bo);
1908 	lockmgr(&glob->lru_lock, LK_RELEASE);
1909 
1910 	ttm_bo_list_ref_sub(bo, put_count, true);
1911 
1912 	/**
1913 	 * Wait for GPU, then move to system cached.
1914 	 */
1915 
1916 	lockmgr(&bo->bdev->fence_lock, LK_EXCLUSIVE);
1917 	ret = ttm_bo_wait(bo, false, false, false);
1918 	lockmgr(&bo->bdev->fence_lock, LK_RELEASE);
1919 
1920 	if (unlikely(ret != 0))
1921 		goto out;
1922 
1923 	if ((bo->mem.placement & swap_placement) != swap_placement) {
1924 		struct ttm_mem_reg evict_mem;
1925 
1926 		evict_mem = bo->mem;
1927 		evict_mem.mm_node = NULL;
1928 		evict_mem.placement = TTM_PL_FLAG_SYSTEM | TTM_PL_FLAG_CACHED;
1929 		evict_mem.mem_type = TTM_PL_SYSTEM;
1930 
1931 		ret = ttm_bo_handle_move_mem(bo, &evict_mem, true,
1932 					     false, false);
1933 		if (unlikely(ret != 0))
1934 			goto out;
1935 	}
1936 
1937 	ttm_bo_unmap_virtual(bo);
1938 
1939 	/**
1940 	 * Swap out. Buffer will be swapped in again as soon as
1941 	 * anyone tries to access a ttm page.
1942 	 */
1943 
1944 	if (bo->bdev->driver->swap_notify)
1945 		bo->bdev->driver->swap_notify(bo);
1946 
1947 	ret = ttm_tt_swapout(bo->ttm, bo->persistent_swap_storage);
1948 out:
1949 
1950 	/**
1951 	 *
1952 	 * Unreserve without putting on LRU to avoid swapping out an
1953 	 * already swapped buffer.
1954 	 */
1955 
1956 	ttm_bo_unreserve_core(bo);
1957 	kref_put(&bo->list_kref, ttm_bo_release_list);
1958 	return ret;
1959 }
1960 
1961 void ttm_bo_swapout_all(struct ttm_bo_device *bdev)
1962 {
1963 	while (ttm_bo_swapout(&bdev->glob->shrink) == 0)
1964 		;
1965 }
1966 EXPORT_SYMBOL(ttm_bo_swapout_all);
1967