xref: /openbmc/linux/drivers/gpu/drm/vc4/vc4_bo.c (revision c616fb0c)
1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3  *  Copyright © 2015 Broadcom
4  */
5 
6 /**
7  * DOC: VC4 GEM BO management support
8  *
9  * The VC4 GPU architecture (both scanout and rendering) has direct
10  * access to system memory with no MMU in between.  To support it, we
11  * use the GEM DMA helper functions to allocate contiguous ranges of
12  * physical memory for our BOs.
13  *
14  * Since the DMA allocator is very slow, we keep a cache of recently
15  * freed BOs around so that the kernel's allocation of objects for 3D
16  * rendering can return quickly.
17  */
18 
19 #include <linux/dma-buf.h>
20 
21 #include <drm/drm_fourcc.h>
22 
23 #include "vc4_drv.h"
24 #include "uapi/drm/vc4_drm.h"
25 
26 static const struct drm_gem_object_funcs vc4_gem_object_funcs;
27 
28 static const char * const bo_type_names[] = {
29 	"kernel",
30 	"V3D",
31 	"V3D shader",
32 	"dumb",
33 	"binner",
34 	"RCL",
35 	"BCL",
36 	"kernel BO cache",
37 };
38 
39 static bool is_user_label(int label)
40 {
41 	return label >= VC4_BO_TYPE_COUNT;
42 }
43 
44 static void vc4_bo_stats_print(struct drm_printer *p, struct vc4_dev *vc4)
45 {
46 	int i;
47 
48 	for (i = 0; i < vc4->num_labels; i++) {
49 		if (!vc4->bo_labels[i].num_allocated)
50 			continue;
51 
52 		drm_printf(p, "%30s: %6dkb BOs (%d)\n",
53 			   vc4->bo_labels[i].name,
54 			   vc4->bo_labels[i].size_allocated / 1024,
55 			   vc4->bo_labels[i].num_allocated);
56 	}
57 
58 	mutex_lock(&vc4->purgeable.lock);
59 	if (vc4->purgeable.num)
60 		drm_printf(p, "%30s: %6zdkb BOs (%d)\n", "userspace BO cache",
61 			   vc4->purgeable.size / 1024, vc4->purgeable.num);
62 
63 	if (vc4->purgeable.purged_num)
64 		drm_printf(p, "%30s: %6zdkb BOs (%d)\n", "total purged BO",
65 			   vc4->purgeable.purged_size / 1024,
66 			   vc4->purgeable.purged_num);
67 	mutex_unlock(&vc4->purgeable.lock);
68 }
69 
70 static int vc4_bo_stats_debugfs(struct seq_file *m, void *unused)
71 {
72 	struct drm_debugfs_entry *entry = m->private;
73 	struct drm_device *dev = entry->dev;
74 	struct vc4_dev *vc4 = to_vc4_dev(dev);
75 	struct drm_printer p = drm_seq_file_printer(m);
76 
77 	vc4_bo_stats_print(&p, vc4);
78 
79 	return 0;
80 }
81 
82 /* Takes ownership of *name and returns the appropriate slot for it in
83  * the bo_labels[] array, extending it as necessary.
84  *
85  * This is inefficient and could use a hash table instead of walking
86  * an array and strcmp()ing.  However, the assumption is that user
87  * labeling will be infrequent (scanout buffers and other long-lived
88  * objects, or debug driver builds), so we can live with it for now.
89  */
90 static int vc4_get_user_label(struct vc4_dev *vc4, const char *name)
91 {
92 	int i;
93 	int free_slot = -1;
94 
95 	for (i = 0; i < vc4->num_labels; i++) {
96 		if (!vc4->bo_labels[i].name) {
97 			free_slot = i;
98 		} else if (strcmp(vc4->bo_labels[i].name, name) == 0) {
99 			kfree(name);
100 			return i;
101 		}
102 	}
103 
104 	if (free_slot != -1) {
105 		WARN_ON(vc4->bo_labels[free_slot].num_allocated != 0);
106 		vc4->bo_labels[free_slot].name = name;
107 		return free_slot;
108 	} else {
109 		u32 new_label_count = vc4->num_labels + 1;
110 		struct vc4_label *new_labels =
111 			krealloc(vc4->bo_labels,
112 				 new_label_count * sizeof(*new_labels),
113 				 GFP_KERNEL);
114 
115 		if (!new_labels) {
116 			kfree(name);
117 			return -1;
118 		}
119 
120 		free_slot = vc4->num_labels;
121 		vc4->bo_labels = new_labels;
122 		vc4->num_labels = new_label_count;
123 
124 		vc4->bo_labels[free_slot].name = name;
125 		vc4->bo_labels[free_slot].num_allocated = 0;
126 		vc4->bo_labels[free_slot].size_allocated = 0;
127 
128 		return free_slot;
129 	}
130 }
131 
132 static void vc4_bo_set_label(struct drm_gem_object *gem_obj, int label)
133 {
134 	struct vc4_bo *bo = to_vc4_bo(gem_obj);
135 	struct vc4_dev *vc4 = to_vc4_dev(gem_obj->dev);
136 
137 	lockdep_assert_held(&vc4->bo_lock);
138 
139 	if (label != -1) {
140 		vc4->bo_labels[label].num_allocated++;
141 		vc4->bo_labels[label].size_allocated += gem_obj->size;
142 	}
143 
144 	vc4->bo_labels[bo->label].num_allocated--;
145 	vc4->bo_labels[bo->label].size_allocated -= gem_obj->size;
146 
147 	if (vc4->bo_labels[bo->label].num_allocated == 0 &&
148 	    is_user_label(bo->label)) {
149 		/* Free user BO label slots on last unreference.
150 		 * Slots are just where we track the stats for a given
151 		 * name, and once a name is unused we can reuse that
152 		 * slot.
153 		 */
154 		kfree(vc4->bo_labels[bo->label].name);
155 		vc4->bo_labels[bo->label].name = NULL;
156 	}
157 
158 	bo->label = label;
159 }
160 
161 static uint32_t bo_page_index(size_t size)
162 {
163 	return (size / PAGE_SIZE) - 1;
164 }
165 
166 static void vc4_bo_destroy(struct vc4_bo *bo)
167 {
168 	struct drm_gem_object *obj = &bo->base.base;
169 	struct vc4_dev *vc4 = to_vc4_dev(obj->dev);
170 
171 	lockdep_assert_held(&vc4->bo_lock);
172 
173 	vc4_bo_set_label(obj, -1);
174 
175 	if (bo->validated_shader) {
176 		kfree(bo->validated_shader->uniform_addr_offsets);
177 		kfree(bo->validated_shader->texture_samples);
178 		kfree(bo->validated_shader);
179 		bo->validated_shader = NULL;
180 	}
181 
182 	mutex_destroy(&bo->madv_lock);
183 	drm_gem_dma_free(&bo->base);
184 }
185 
186 static void vc4_bo_remove_from_cache(struct vc4_bo *bo)
187 {
188 	struct vc4_dev *vc4 = to_vc4_dev(bo->base.base.dev);
189 
190 	lockdep_assert_held(&vc4->bo_lock);
191 	list_del(&bo->unref_head);
192 	list_del(&bo->size_head);
193 }
194 
195 static struct list_head *vc4_get_cache_list_for_size(struct drm_device *dev,
196 						     size_t size)
197 {
198 	struct vc4_dev *vc4 = to_vc4_dev(dev);
199 	uint32_t page_index = bo_page_index(size);
200 
201 	if (vc4->bo_cache.size_list_size <= page_index) {
202 		uint32_t new_size = max(vc4->bo_cache.size_list_size * 2,
203 					page_index + 1);
204 		struct list_head *new_list;
205 		uint32_t i;
206 
207 		new_list = kmalloc_array(new_size, sizeof(struct list_head),
208 					 GFP_KERNEL);
209 		if (!new_list)
210 			return NULL;
211 
212 		/* Rebase the old cached BO lists to their new list
213 		 * head locations.
214 		 */
215 		for (i = 0; i < vc4->bo_cache.size_list_size; i++) {
216 			struct list_head *old_list =
217 				&vc4->bo_cache.size_list[i];
218 
219 			if (list_empty(old_list))
220 				INIT_LIST_HEAD(&new_list[i]);
221 			else
222 				list_replace(old_list, &new_list[i]);
223 		}
224 		/* And initialize the brand new BO list heads. */
225 		for (i = vc4->bo_cache.size_list_size; i < new_size; i++)
226 			INIT_LIST_HEAD(&new_list[i]);
227 
228 		kfree(vc4->bo_cache.size_list);
229 		vc4->bo_cache.size_list = new_list;
230 		vc4->bo_cache.size_list_size = new_size;
231 	}
232 
233 	return &vc4->bo_cache.size_list[page_index];
234 }
235 
236 static void vc4_bo_cache_purge(struct drm_device *dev)
237 {
238 	struct vc4_dev *vc4 = to_vc4_dev(dev);
239 
240 	mutex_lock(&vc4->bo_lock);
241 	while (!list_empty(&vc4->bo_cache.time_list)) {
242 		struct vc4_bo *bo = list_last_entry(&vc4->bo_cache.time_list,
243 						    struct vc4_bo, unref_head);
244 		vc4_bo_remove_from_cache(bo);
245 		vc4_bo_destroy(bo);
246 	}
247 	mutex_unlock(&vc4->bo_lock);
248 }
249 
250 void vc4_bo_add_to_purgeable_pool(struct vc4_bo *bo)
251 {
252 	struct vc4_dev *vc4 = to_vc4_dev(bo->base.base.dev);
253 
254 	if (WARN_ON_ONCE(vc4->is_vc5))
255 		return;
256 
257 	mutex_lock(&vc4->purgeable.lock);
258 	list_add_tail(&bo->size_head, &vc4->purgeable.list);
259 	vc4->purgeable.num++;
260 	vc4->purgeable.size += bo->base.base.size;
261 	mutex_unlock(&vc4->purgeable.lock);
262 }
263 
264 static void vc4_bo_remove_from_purgeable_pool_locked(struct vc4_bo *bo)
265 {
266 	struct vc4_dev *vc4 = to_vc4_dev(bo->base.base.dev);
267 
268 	if (WARN_ON_ONCE(vc4->is_vc5))
269 		return;
270 
271 	/* list_del_init() is used here because the caller might release
272 	 * the purgeable lock in order to acquire the madv one and update the
273 	 * madv status.
274 	 * During this short period of time a user might decide to mark
275 	 * the BO as unpurgeable, and if bo->madv is set to
276 	 * VC4_MADV_DONTNEED it will try to remove the BO from the
277 	 * purgeable list which will fail if the ->next/prev fields
278 	 * are set to LIST_POISON1/LIST_POISON2 (which is what
279 	 * list_del() does).
280 	 * Re-initializing the list element guarantees that list_del()
281 	 * will work correctly even if it's a NOP.
282 	 */
283 	list_del_init(&bo->size_head);
284 	vc4->purgeable.num--;
285 	vc4->purgeable.size -= bo->base.base.size;
286 }
287 
288 void vc4_bo_remove_from_purgeable_pool(struct vc4_bo *bo)
289 {
290 	struct vc4_dev *vc4 = to_vc4_dev(bo->base.base.dev);
291 
292 	mutex_lock(&vc4->purgeable.lock);
293 	vc4_bo_remove_from_purgeable_pool_locked(bo);
294 	mutex_unlock(&vc4->purgeable.lock);
295 }
296 
297 static void vc4_bo_purge(struct drm_gem_object *obj)
298 {
299 	struct vc4_bo *bo = to_vc4_bo(obj);
300 	struct drm_device *dev = obj->dev;
301 
302 	WARN_ON(!mutex_is_locked(&bo->madv_lock));
303 	WARN_ON(bo->madv != VC4_MADV_DONTNEED);
304 
305 	drm_vma_node_unmap(&obj->vma_node, dev->anon_inode->i_mapping);
306 
307 	dma_free_wc(dev->dev, obj->size, bo->base.vaddr, bo->base.dma_addr);
308 	bo->base.vaddr = NULL;
309 	bo->madv = __VC4_MADV_PURGED;
310 }
311 
312 static void vc4_bo_userspace_cache_purge(struct drm_device *dev)
313 {
314 	struct vc4_dev *vc4 = to_vc4_dev(dev);
315 
316 	mutex_lock(&vc4->purgeable.lock);
317 	while (!list_empty(&vc4->purgeable.list)) {
318 		struct vc4_bo *bo = list_first_entry(&vc4->purgeable.list,
319 						     struct vc4_bo, size_head);
320 		struct drm_gem_object *obj = &bo->base.base;
321 		size_t purged_size = 0;
322 
323 		vc4_bo_remove_from_purgeable_pool_locked(bo);
324 
325 		/* Release the purgeable lock while we're purging the BO so
326 		 * that other people can continue inserting things in the
327 		 * purgeable pool without having to wait for all BOs to be
328 		 * purged.
329 		 */
330 		mutex_unlock(&vc4->purgeable.lock);
331 		mutex_lock(&bo->madv_lock);
332 
333 		/* Since we released the purgeable pool lock before acquiring
334 		 * the BO madv one, the user may have marked the BO as WILLNEED
335 		 * and re-used it in the meantime.
336 		 * Before purging the BO we need to make sure
337 		 * - it is still marked as DONTNEED
338 		 * - it has not been re-inserted in the purgeable list
339 		 * - it is not used by HW blocks
340 		 * If one of these conditions is not met, just skip the entry.
341 		 */
342 		if (bo->madv == VC4_MADV_DONTNEED &&
343 		    list_empty(&bo->size_head) &&
344 		    !refcount_read(&bo->usecnt)) {
345 			purged_size = bo->base.base.size;
346 			vc4_bo_purge(obj);
347 		}
348 		mutex_unlock(&bo->madv_lock);
349 		mutex_lock(&vc4->purgeable.lock);
350 
351 		if (purged_size) {
352 			vc4->purgeable.purged_size += purged_size;
353 			vc4->purgeable.purged_num++;
354 		}
355 	}
356 	mutex_unlock(&vc4->purgeable.lock);
357 }
358 
359 static struct vc4_bo *vc4_bo_get_from_cache(struct drm_device *dev,
360 					    uint32_t size,
361 					    enum vc4_kernel_bo_type type)
362 {
363 	struct vc4_dev *vc4 = to_vc4_dev(dev);
364 	uint32_t page_index = bo_page_index(size);
365 	struct vc4_bo *bo = NULL;
366 
367 	mutex_lock(&vc4->bo_lock);
368 	if (page_index >= vc4->bo_cache.size_list_size)
369 		goto out;
370 
371 	if (list_empty(&vc4->bo_cache.size_list[page_index]))
372 		goto out;
373 
374 	bo = list_first_entry(&vc4->bo_cache.size_list[page_index],
375 			      struct vc4_bo, size_head);
376 	vc4_bo_remove_from_cache(bo);
377 	kref_init(&bo->base.base.refcount);
378 
379 out:
380 	if (bo)
381 		vc4_bo_set_label(&bo->base.base, type);
382 	mutex_unlock(&vc4->bo_lock);
383 	return bo;
384 }
385 
386 /**
387  * vc4_create_object - Implementation of driver->gem_create_object.
388  * @dev: DRM device
389  * @size: Size in bytes of the memory the object will reference
390  *
391  * This lets the DMA helpers allocate object structs for us, and keep
392  * our BO stats correct.
393  */
394 struct drm_gem_object *vc4_create_object(struct drm_device *dev, size_t size)
395 {
396 	struct vc4_dev *vc4 = to_vc4_dev(dev);
397 	struct vc4_bo *bo;
398 
399 	if (WARN_ON_ONCE(vc4->is_vc5))
400 		return ERR_PTR(-ENODEV);
401 
402 	bo = kzalloc(sizeof(*bo), GFP_KERNEL);
403 	if (!bo)
404 		return ERR_PTR(-ENOMEM);
405 
406 	bo->madv = VC4_MADV_WILLNEED;
407 	refcount_set(&bo->usecnt, 0);
408 
409 	mutex_init(&bo->madv_lock);
410 
411 	mutex_lock(&vc4->bo_lock);
412 	bo->label = VC4_BO_TYPE_KERNEL;
413 	vc4->bo_labels[VC4_BO_TYPE_KERNEL].num_allocated++;
414 	vc4->bo_labels[VC4_BO_TYPE_KERNEL].size_allocated += size;
415 	mutex_unlock(&vc4->bo_lock);
416 
417 	bo->base.base.funcs = &vc4_gem_object_funcs;
418 
419 	return &bo->base.base;
420 }
421 
422 struct vc4_bo *vc4_bo_create(struct drm_device *dev, size_t unaligned_size,
423 			     bool allow_unzeroed, enum vc4_kernel_bo_type type)
424 {
425 	size_t size = roundup(unaligned_size, PAGE_SIZE);
426 	struct vc4_dev *vc4 = to_vc4_dev(dev);
427 	struct drm_gem_dma_object *dma_obj;
428 	struct vc4_bo *bo;
429 
430 	if (WARN_ON_ONCE(vc4->is_vc5))
431 		return ERR_PTR(-ENODEV);
432 
433 	if (size == 0)
434 		return ERR_PTR(-EINVAL);
435 
436 	/* First, try to get a vc4_bo from the kernel BO cache. */
437 	bo = vc4_bo_get_from_cache(dev, size, type);
438 	if (bo) {
439 		if (!allow_unzeroed)
440 			memset(bo->base.vaddr, 0, bo->base.base.size);
441 		return bo;
442 	}
443 
444 	dma_obj = drm_gem_dma_create(dev, size);
445 	if (IS_ERR(dma_obj)) {
446 		/*
447 		 * If we've run out of DMA memory, kill the cache of
448 		 * DMA allocations we've got laying around and try again.
449 		 */
450 		vc4_bo_cache_purge(dev);
451 		dma_obj = drm_gem_dma_create(dev, size);
452 	}
453 
454 	if (IS_ERR(dma_obj)) {
455 		/*
456 		 * Still not enough DMA memory, purge the userspace BO
457 		 * cache and retry.
458 		 * This is sub-optimal since we purge the whole userspace
459 		 * BO cache which forces user that want to re-use the BO to
460 		 * restore its initial content.
461 		 * Ideally, we should purge entries one by one and retry
462 		 * after each to see if DMA allocation succeeds. Or even
463 		 * better, try to find an entry with at least the same
464 		 * size.
465 		 */
466 		vc4_bo_userspace_cache_purge(dev);
467 		dma_obj = drm_gem_dma_create(dev, size);
468 	}
469 
470 	if (IS_ERR(dma_obj)) {
471 		struct drm_printer p = drm_info_printer(vc4->base.dev);
472 		DRM_ERROR("Failed to allocate from GEM DMA helper:\n");
473 		vc4_bo_stats_print(&p, vc4);
474 		return ERR_PTR(-ENOMEM);
475 	}
476 	bo = to_vc4_bo(&dma_obj->base);
477 
478 	/* By default, BOs do not support the MADV ioctl. This will be enabled
479 	 * only on BOs that are exposed to userspace (V3D, V3D_SHADER and DUMB
480 	 * BOs).
481 	 */
482 	bo->madv = __VC4_MADV_NOTSUPP;
483 
484 	mutex_lock(&vc4->bo_lock);
485 	vc4_bo_set_label(&dma_obj->base, type);
486 	mutex_unlock(&vc4->bo_lock);
487 
488 	return bo;
489 }
490 
491 int vc4_bo_dumb_create(struct drm_file *file_priv,
492 		       struct drm_device *dev,
493 		       struct drm_mode_create_dumb *args)
494 {
495 	struct vc4_dev *vc4 = to_vc4_dev(dev);
496 	struct vc4_bo *bo = NULL;
497 	int ret;
498 
499 	if (WARN_ON_ONCE(vc4->is_vc5))
500 		return -ENODEV;
501 
502 	ret = vc4_dumb_fixup_args(args);
503 	if (ret)
504 		return ret;
505 
506 	bo = vc4_bo_create(dev, args->size, false, VC4_BO_TYPE_DUMB);
507 	if (IS_ERR(bo))
508 		return PTR_ERR(bo);
509 
510 	bo->madv = VC4_MADV_WILLNEED;
511 
512 	ret = drm_gem_handle_create(file_priv, &bo->base.base, &args->handle);
513 	drm_gem_object_put(&bo->base.base);
514 
515 	return ret;
516 }
517 
518 static void vc4_bo_cache_free_old(struct drm_device *dev)
519 {
520 	struct vc4_dev *vc4 = to_vc4_dev(dev);
521 	unsigned long expire_time = jiffies - msecs_to_jiffies(1000);
522 
523 	lockdep_assert_held(&vc4->bo_lock);
524 
525 	while (!list_empty(&vc4->bo_cache.time_list)) {
526 		struct vc4_bo *bo = list_last_entry(&vc4->bo_cache.time_list,
527 						    struct vc4_bo, unref_head);
528 		if (time_before(expire_time, bo->free_time)) {
529 			mod_timer(&vc4->bo_cache.time_timer,
530 				  round_jiffies_up(jiffies +
531 						   msecs_to_jiffies(1000)));
532 			return;
533 		}
534 
535 		vc4_bo_remove_from_cache(bo);
536 		vc4_bo_destroy(bo);
537 	}
538 }
539 
540 /* Called on the last userspace/kernel unreference of the BO.  Returns
541  * it to the BO cache if possible, otherwise frees it.
542  */
543 static void vc4_free_object(struct drm_gem_object *gem_bo)
544 {
545 	struct drm_device *dev = gem_bo->dev;
546 	struct vc4_dev *vc4 = to_vc4_dev(dev);
547 	struct vc4_bo *bo = to_vc4_bo(gem_bo);
548 	struct list_head *cache_list;
549 
550 	/* Remove the BO from the purgeable list. */
551 	mutex_lock(&bo->madv_lock);
552 	if (bo->madv == VC4_MADV_DONTNEED && !refcount_read(&bo->usecnt))
553 		vc4_bo_remove_from_purgeable_pool(bo);
554 	mutex_unlock(&bo->madv_lock);
555 
556 	mutex_lock(&vc4->bo_lock);
557 	/* If the object references someone else's memory, we can't cache it.
558 	 */
559 	if (gem_bo->import_attach) {
560 		vc4_bo_destroy(bo);
561 		goto out;
562 	}
563 
564 	/* Don't cache if it was publicly named. */
565 	if (gem_bo->name) {
566 		vc4_bo_destroy(bo);
567 		goto out;
568 	}
569 
570 	/* If this object was partially constructed but DMA allocation
571 	 * had failed, just free it. Can also happen when the BO has been
572 	 * purged.
573 	 */
574 	if (!bo->base.vaddr) {
575 		vc4_bo_destroy(bo);
576 		goto out;
577 	}
578 
579 	cache_list = vc4_get_cache_list_for_size(dev, gem_bo->size);
580 	if (!cache_list) {
581 		vc4_bo_destroy(bo);
582 		goto out;
583 	}
584 
585 	if (bo->validated_shader) {
586 		kfree(bo->validated_shader->uniform_addr_offsets);
587 		kfree(bo->validated_shader->texture_samples);
588 		kfree(bo->validated_shader);
589 		bo->validated_shader = NULL;
590 	}
591 
592 	/* Reset madv and usecnt before adding the BO to the cache. */
593 	bo->madv = __VC4_MADV_NOTSUPP;
594 	refcount_set(&bo->usecnt, 0);
595 
596 	bo->t_format = false;
597 	bo->free_time = jiffies;
598 	list_add(&bo->size_head, cache_list);
599 	list_add(&bo->unref_head, &vc4->bo_cache.time_list);
600 
601 	vc4_bo_set_label(&bo->base.base, VC4_BO_TYPE_KERNEL_CACHE);
602 
603 	vc4_bo_cache_free_old(dev);
604 
605 out:
606 	mutex_unlock(&vc4->bo_lock);
607 }
608 
609 static void vc4_bo_cache_time_work(struct work_struct *work)
610 {
611 	struct vc4_dev *vc4 =
612 		container_of(work, struct vc4_dev, bo_cache.time_work);
613 	struct drm_device *dev = &vc4->base;
614 
615 	mutex_lock(&vc4->bo_lock);
616 	vc4_bo_cache_free_old(dev);
617 	mutex_unlock(&vc4->bo_lock);
618 }
619 
620 int vc4_bo_inc_usecnt(struct vc4_bo *bo)
621 {
622 	struct vc4_dev *vc4 = to_vc4_dev(bo->base.base.dev);
623 	int ret;
624 
625 	if (WARN_ON_ONCE(vc4->is_vc5))
626 		return -ENODEV;
627 
628 	/* Fast path: if the BO is already retained by someone, no need to
629 	 * check the madv status.
630 	 */
631 	if (refcount_inc_not_zero(&bo->usecnt))
632 		return 0;
633 
634 	mutex_lock(&bo->madv_lock);
635 	switch (bo->madv) {
636 	case VC4_MADV_WILLNEED:
637 		if (!refcount_inc_not_zero(&bo->usecnt))
638 			refcount_set(&bo->usecnt, 1);
639 		ret = 0;
640 		break;
641 	case VC4_MADV_DONTNEED:
642 		/* We shouldn't use a BO marked as purgeable if at least
643 		 * someone else retained its content by incrementing usecnt.
644 		 * Luckily the BO hasn't been purged yet, but something wrong
645 		 * is happening here. Just throw an error instead of
646 		 * authorizing this use case.
647 		 */
648 	case __VC4_MADV_PURGED:
649 		/* We can't use a purged BO. */
650 	default:
651 		/* Invalid madv value. */
652 		ret = -EINVAL;
653 		break;
654 	}
655 	mutex_unlock(&bo->madv_lock);
656 
657 	return ret;
658 }
659 
660 void vc4_bo_dec_usecnt(struct vc4_bo *bo)
661 {
662 	struct vc4_dev *vc4 = to_vc4_dev(bo->base.base.dev);
663 
664 	if (WARN_ON_ONCE(vc4->is_vc5))
665 		return;
666 
667 	/* Fast path: if the BO is still retained by someone, no need to test
668 	 * the madv value.
669 	 */
670 	if (refcount_dec_not_one(&bo->usecnt))
671 		return;
672 
673 	mutex_lock(&bo->madv_lock);
674 	if (refcount_dec_and_test(&bo->usecnt) &&
675 	    bo->madv == VC4_MADV_DONTNEED)
676 		vc4_bo_add_to_purgeable_pool(bo);
677 	mutex_unlock(&bo->madv_lock);
678 }
679 
680 static void vc4_bo_cache_time_timer(struct timer_list *t)
681 {
682 	struct vc4_dev *vc4 = from_timer(vc4, t, bo_cache.time_timer);
683 
684 	schedule_work(&vc4->bo_cache.time_work);
685 }
686 
687 static struct dma_buf *vc4_prime_export(struct drm_gem_object *obj, int flags)
688 {
689 	struct vc4_bo *bo = to_vc4_bo(obj);
690 	struct dma_buf *dmabuf;
691 	int ret;
692 
693 	if (bo->validated_shader) {
694 		DRM_DEBUG("Attempting to export shader BO\n");
695 		return ERR_PTR(-EINVAL);
696 	}
697 
698 	/* Note: as soon as the BO is exported it becomes unpurgeable, because
699 	 * noone ever decrements the usecnt even if the reference held by the
700 	 * exported BO is released. This shouldn't be a problem since we don't
701 	 * expect exported BOs to be marked as purgeable.
702 	 */
703 	ret = vc4_bo_inc_usecnt(bo);
704 	if (ret) {
705 		DRM_ERROR("Failed to increment BO usecnt\n");
706 		return ERR_PTR(ret);
707 	}
708 
709 	dmabuf = drm_gem_prime_export(obj, flags);
710 	if (IS_ERR(dmabuf))
711 		vc4_bo_dec_usecnt(bo);
712 
713 	return dmabuf;
714 }
715 
716 static vm_fault_t vc4_fault(struct vm_fault *vmf)
717 {
718 	struct vm_area_struct *vma = vmf->vma;
719 	struct drm_gem_object *obj = vma->vm_private_data;
720 	struct vc4_bo *bo = to_vc4_bo(obj);
721 
722 	/* The only reason we would end up here is when user-space accesses
723 	 * BO's memory after it's been purged.
724 	 */
725 	mutex_lock(&bo->madv_lock);
726 	WARN_ON(bo->madv != __VC4_MADV_PURGED);
727 	mutex_unlock(&bo->madv_lock);
728 
729 	return VM_FAULT_SIGBUS;
730 }
731 
732 static int vc4_gem_object_mmap(struct drm_gem_object *obj, struct vm_area_struct *vma)
733 {
734 	struct vc4_bo *bo = to_vc4_bo(obj);
735 
736 	if (bo->validated_shader && (vma->vm_flags & VM_WRITE)) {
737 		DRM_DEBUG("mmapping of shader BOs for writing not allowed.\n");
738 		return -EINVAL;
739 	}
740 
741 	if (bo->madv != VC4_MADV_WILLNEED) {
742 		DRM_DEBUG("mmapping of %s BO not allowed\n",
743 			  bo->madv == VC4_MADV_DONTNEED ?
744 			  "purgeable" : "purged");
745 		return -EINVAL;
746 	}
747 
748 	return drm_gem_dma_mmap(&bo->base, vma);
749 }
750 
751 static const struct vm_operations_struct vc4_vm_ops = {
752 	.fault = vc4_fault,
753 	.open = drm_gem_vm_open,
754 	.close = drm_gem_vm_close,
755 };
756 
757 static const struct drm_gem_object_funcs vc4_gem_object_funcs = {
758 	.free = vc4_free_object,
759 	.export = vc4_prime_export,
760 	.get_sg_table = drm_gem_dma_object_get_sg_table,
761 	.vmap = drm_gem_dma_object_vmap,
762 	.mmap = vc4_gem_object_mmap,
763 	.vm_ops = &vc4_vm_ops,
764 };
765 
766 static int vc4_grab_bin_bo(struct vc4_dev *vc4, struct vc4_file *vc4file)
767 {
768 	if (!vc4->v3d)
769 		return -ENODEV;
770 
771 	if (vc4file->bin_bo_used)
772 		return 0;
773 
774 	return vc4_v3d_bin_bo_get(vc4, &vc4file->bin_bo_used);
775 }
776 
777 int vc4_create_bo_ioctl(struct drm_device *dev, void *data,
778 			struct drm_file *file_priv)
779 {
780 	struct drm_vc4_create_bo *args = data;
781 	struct vc4_file *vc4file = file_priv->driver_priv;
782 	struct vc4_dev *vc4 = to_vc4_dev(dev);
783 	struct vc4_bo *bo = NULL;
784 	int ret;
785 
786 	if (WARN_ON_ONCE(vc4->is_vc5))
787 		return -ENODEV;
788 
789 	ret = vc4_grab_bin_bo(vc4, vc4file);
790 	if (ret)
791 		return ret;
792 
793 	/*
794 	 * We can't allocate from the BO cache, because the BOs don't
795 	 * get zeroed, and that might leak data between users.
796 	 */
797 	bo = vc4_bo_create(dev, args->size, false, VC4_BO_TYPE_V3D);
798 	if (IS_ERR(bo))
799 		return PTR_ERR(bo);
800 
801 	bo->madv = VC4_MADV_WILLNEED;
802 
803 	ret = drm_gem_handle_create(file_priv, &bo->base.base, &args->handle);
804 	drm_gem_object_put(&bo->base.base);
805 
806 	return ret;
807 }
808 
809 int vc4_mmap_bo_ioctl(struct drm_device *dev, void *data,
810 		      struct drm_file *file_priv)
811 {
812 	struct vc4_dev *vc4 = to_vc4_dev(dev);
813 	struct drm_vc4_mmap_bo *args = data;
814 	struct drm_gem_object *gem_obj;
815 
816 	if (WARN_ON_ONCE(vc4->is_vc5))
817 		return -ENODEV;
818 
819 	gem_obj = drm_gem_object_lookup(file_priv, args->handle);
820 	if (!gem_obj) {
821 		DRM_DEBUG("Failed to look up GEM BO %d\n", args->handle);
822 		return -EINVAL;
823 	}
824 
825 	/* The mmap offset was set up at BO allocation time. */
826 	args->offset = drm_vma_node_offset_addr(&gem_obj->vma_node);
827 
828 	drm_gem_object_put(gem_obj);
829 	return 0;
830 }
831 
832 int
833 vc4_create_shader_bo_ioctl(struct drm_device *dev, void *data,
834 			   struct drm_file *file_priv)
835 {
836 	struct drm_vc4_create_shader_bo *args = data;
837 	struct vc4_file *vc4file = file_priv->driver_priv;
838 	struct vc4_dev *vc4 = to_vc4_dev(dev);
839 	struct vc4_bo *bo = NULL;
840 	int ret;
841 
842 	if (WARN_ON_ONCE(vc4->is_vc5))
843 		return -ENODEV;
844 
845 	if (args->size == 0)
846 		return -EINVAL;
847 
848 	if (args->size % sizeof(u64) != 0)
849 		return -EINVAL;
850 
851 	if (args->flags != 0) {
852 		DRM_INFO("Unknown flags set: 0x%08x\n", args->flags);
853 		return -EINVAL;
854 	}
855 
856 	if (args->pad != 0) {
857 		DRM_INFO("Pad set: 0x%08x\n", args->pad);
858 		return -EINVAL;
859 	}
860 
861 	ret = vc4_grab_bin_bo(vc4, vc4file);
862 	if (ret)
863 		return ret;
864 
865 	bo = vc4_bo_create(dev, args->size, true, VC4_BO_TYPE_V3D_SHADER);
866 	if (IS_ERR(bo))
867 		return PTR_ERR(bo);
868 
869 	bo->madv = VC4_MADV_WILLNEED;
870 
871 	if (copy_from_user(bo->base.vaddr,
872 			     (void __user *)(uintptr_t)args->data,
873 			     args->size)) {
874 		ret = -EFAULT;
875 		goto fail;
876 	}
877 	/* Clear the rest of the memory from allocating from the BO
878 	 * cache.
879 	 */
880 	memset(bo->base.vaddr + args->size, 0,
881 	       bo->base.base.size - args->size);
882 
883 	bo->validated_shader = vc4_validate_shader(&bo->base);
884 	if (!bo->validated_shader) {
885 		ret = -EINVAL;
886 		goto fail;
887 	}
888 
889 	/* We have to create the handle after validation, to avoid
890 	 * races for users to do doing things like mmap the shader BO.
891 	 */
892 	ret = drm_gem_handle_create(file_priv, &bo->base.base, &args->handle);
893 
894 fail:
895 	drm_gem_object_put(&bo->base.base);
896 
897 	return ret;
898 }
899 
900 /**
901  * vc4_set_tiling_ioctl() - Sets the tiling modifier for a BO.
902  * @dev: DRM device
903  * @data: ioctl argument
904  * @file_priv: DRM file for this fd
905  *
906  * The tiling state of the BO decides the default modifier of an fb if
907  * no specific modifier was set by userspace, and the return value of
908  * vc4_get_tiling_ioctl() (so that userspace can treat a BO it
909  * received from dmabuf as the same tiling format as the producer
910  * used).
911  */
912 int vc4_set_tiling_ioctl(struct drm_device *dev, void *data,
913 			 struct drm_file *file_priv)
914 {
915 	struct vc4_dev *vc4 = to_vc4_dev(dev);
916 	struct drm_vc4_set_tiling *args = data;
917 	struct drm_gem_object *gem_obj;
918 	struct vc4_bo *bo;
919 	bool t_format;
920 
921 	if (WARN_ON_ONCE(vc4->is_vc5))
922 		return -ENODEV;
923 
924 	if (args->flags != 0)
925 		return -EINVAL;
926 
927 	switch (args->modifier) {
928 	case DRM_FORMAT_MOD_NONE:
929 		t_format = false;
930 		break;
931 	case DRM_FORMAT_MOD_BROADCOM_VC4_T_TILED:
932 		t_format = true;
933 		break;
934 	default:
935 		return -EINVAL;
936 	}
937 
938 	gem_obj = drm_gem_object_lookup(file_priv, args->handle);
939 	if (!gem_obj) {
940 		DRM_DEBUG("Failed to look up GEM BO %d\n", args->handle);
941 		return -ENOENT;
942 	}
943 	bo = to_vc4_bo(gem_obj);
944 	bo->t_format = t_format;
945 
946 	drm_gem_object_put(gem_obj);
947 
948 	return 0;
949 }
950 
951 /**
952  * vc4_get_tiling_ioctl() - Gets the tiling modifier for a BO.
953  * @dev: DRM device
954  * @data: ioctl argument
955  * @file_priv: DRM file for this fd
956  *
957  * Returns the tiling modifier for a BO as set by vc4_set_tiling_ioctl().
958  */
959 int vc4_get_tiling_ioctl(struct drm_device *dev, void *data,
960 			 struct drm_file *file_priv)
961 {
962 	struct vc4_dev *vc4 = to_vc4_dev(dev);
963 	struct drm_vc4_get_tiling *args = data;
964 	struct drm_gem_object *gem_obj;
965 	struct vc4_bo *bo;
966 
967 	if (WARN_ON_ONCE(vc4->is_vc5))
968 		return -ENODEV;
969 
970 	if (args->flags != 0 || args->modifier != 0)
971 		return -EINVAL;
972 
973 	gem_obj = drm_gem_object_lookup(file_priv, args->handle);
974 	if (!gem_obj) {
975 		DRM_DEBUG("Failed to look up GEM BO %d\n", args->handle);
976 		return -ENOENT;
977 	}
978 	bo = to_vc4_bo(gem_obj);
979 
980 	if (bo->t_format)
981 		args->modifier = DRM_FORMAT_MOD_BROADCOM_VC4_T_TILED;
982 	else
983 		args->modifier = DRM_FORMAT_MOD_NONE;
984 
985 	drm_gem_object_put(gem_obj);
986 
987 	return 0;
988 }
989 
990 int vc4_bo_debugfs_init(struct drm_minor *minor)
991 {
992 	struct drm_device *drm = minor->dev;
993 	struct vc4_dev *vc4 = to_vc4_dev(drm);
994 
995 	if (!vc4->v3d)
996 		return -ENODEV;
997 
998 	drm_debugfs_add_file(drm, "bo_stats", vc4_bo_stats_debugfs, NULL);
999 
1000 	return 0;
1001 }
1002 
1003 static void vc4_bo_cache_destroy(struct drm_device *dev, void *unused);
1004 int vc4_bo_cache_init(struct drm_device *dev)
1005 {
1006 	struct vc4_dev *vc4 = to_vc4_dev(dev);
1007 	int ret;
1008 	int i;
1009 
1010 	if (WARN_ON_ONCE(vc4->is_vc5))
1011 		return -ENODEV;
1012 
1013 	/* Create the initial set of BO labels that the kernel will
1014 	 * use.  This lets us avoid a bunch of string reallocation in
1015 	 * the kernel's draw and BO allocation paths.
1016 	 */
1017 	vc4->bo_labels = kcalloc(VC4_BO_TYPE_COUNT, sizeof(*vc4->bo_labels),
1018 				 GFP_KERNEL);
1019 	if (!vc4->bo_labels)
1020 		return -ENOMEM;
1021 	vc4->num_labels = VC4_BO_TYPE_COUNT;
1022 
1023 	BUILD_BUG_ON(ARRAY_SIZE(bo_type_names) != VC4_BO_TYPE_COUNT);
1024 	for (i = 0; i < VC4_BO_TYPE_COUNT; i++)
1025 		vc4->bo_labels[i].name = bo_type_names[i];
1026 
1027 	ret = drmm_mutex_init(dev, &vc4->bo_lock);
1028 	if (ret) {
1029 		kfree(vc4->bo_labels);
1030 		return ret;
1031 	}
1032 
1033 	INIT_LIST_HEAD(&vc4->bo_cache.time_list);
1034 
1035 	INIT_WORK(&vc4->bo_cache.time_work, vc4_bo_cache_time_work);
1036 	timer_setup(&vc4->bo_cache.time_timer, vc4_bo_cache_time_timer, 0);
1037 
1038 	return drmm_add_action_or_reset(dev, vc4_bo_cache_destroy, NULL);
1039 }
1040 
1041 static void vc4_bo_cache_destroy(struct drm_device *dev, void *unused)
1042 {
1043 	struct vc4_dev *vc4 = to_vc4_dev(dev);
1044 	int i;
1045 
1046 	del_timer(&vc4->bo_cache.time_timer);
1047 	cancel_work_sync(&vc4->bo_cache.time_work);
1048 
1049 	vc4_bo_cache_purge(dev);
1050 
1051 	for (i = 0; i < vc4->num_labels; i++) {
1052 		if (vc4->bo_labels[i].num_allocated) {
1053 			DRM_ERROR("Destroying BO cache with %d %s "
1054 				  "BOs still allocated\n",
1055 				  vc4->bo_labels[i].num_allocated,
1056 				  vc4->bo_labels[i].name);
1057 		}
1058 
1059 		if (is_user_label(i))
1060 			kfree(vc4->bo_labels[i].name);
1061 	}
1062 	kfree(vc4->bo_labels);
1063 }
1064 
1065 int vc4_label_bo_ioctl(struct drm_device *dev, void *data,
1066 		       struct drm_file *file_priv)
1067 {
1068 	struct vc4_dev *vc4 = to_vc4_dev(dev);
1069 	struct drm_vc4_label_bo *args = data;
1070 	char *name;
1071 	struct drm_gem_object *gem_obj;
1072 	int ret = 0, label;
1073 
1074 	if (WARN_ON_ONCE(vc4->is_vc5))
1075 		return -ENODEV;
1076 
1077 	if (!args->len)
1078 		return -EINVAL;
1079 
1080 	name = strndup_user(u64_to_user_ptr(args->name), args->len + 1);
1081 	if (IS_ERR(name))
1082 		return PTR_ERR(name);
1083 
1084 	gem_obj = drm_gem_object_lookup(file_priv, args->handle);
1085 	if (!gem_obj) {
1086 		DRM_ERROR("Failed to look up GEM BO %d\n", args->handle);
1087 		kfree(name);
1088 		return -ENOENT;
1089 	}
1090 
1091 	mutex_lock(&vc4->bo_lock);
1092 	label = vc4_get_user_label(vc4, name);
1093 	if (label != -1)
1094 		vc4_bo_set_label(gem_obj, label);
1095 	else
1096 		ret = -ENOMEM;
1097 	mutex_unlock(&vc4->bo_lock);
1098 
1099 	drm_gem_object_put(gem_obj);
1100 
1101 	return ret;
1102 }
1103