xref: /openbmc/linux/drivers/gpu/drm/vc4/vc4_bo.c (revision acf50233)
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 CMA helper functions to allocate contiguous ranges of
12  * physical memory for our BOs.
13  *
14  * Since the CMA 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 "vc4_drv.h"
22 #include "uapi/drm/vc4_drm.h"
23 
24 static const struct drm_gem_object_funcs vc4_gem_object_funcs;
25 
26 static const char * const bo_type_names[] = {
27 	"kernel",
28 	"V3D",
29 	"V3D shader",
30 	"dumb",
31 	"binner",
32 	"RCL",
33 	"BCL",
34 	"kernel BO cache",
35 };
36 
37 static bool is_user_label(int label)
38 {
39 	return label >= VC4_BO_TYPE_COUNT;
40 }
41 
42 static void vc4_bo_stats_print(struct drm_printer *p, struct vc4_dev *vc4)
43 {
44 	int i;
45 
46 	for (i = 0; i < vc4->num_labels; i++) {
47 		if (!vc4->bo_labels[i].num_allocated)
48 			continue;
49 
50 		drm_printf(p, "%30s: %6dkb BOs (%d)\n",
51 			   vc4->bo_labels[i].name,
52 			   vc4->bo_labels[i].size_allocated / 1024,
53 			   vc4->bo_labels[i].num_allocated);
54 	}
55 
56 	mutex_lock(&vc4->purgeable.lock);
57 	if (vc4->purgeable.num)
58 		drm_printf(p, "%30s: %6zdkb BOs (%d)\n", "userspace BO cache",
59 			   vc4->purgeable.size / 1024, vc4->purgeable.num);
60 
61 	if (vc4->purgeable.purged_num)
62 		drm_printf(p, "%30s: %6zdkb BOs (%d)\n", "total purged BO",
63 			   vc4->purgeable.purged_size / 1024,
64 			   vc4->purgeable.purged_num);
65 	mutex_unlock(&vc4->purgeable.lock);
66 }
67 
68 static int vc4_bo_stats_debugfs(struct seq_file *m, void *unused)
69 {
70 	struct drm_info_node *node = (struct drm_info_node *)m->private;
71 	struct drm_device *dev = node->minor->dev;
72 	struct vc4_dev *vc4 = to_vc4_dev(dev);
73 	struct drm_printer p = drm_seq_file_printer(m);
74 
75 	vc4_bo_stats_print(&p, vc4);
76 
77 	return 0;
78 }
79 
80 /* Takes ownership of *name and returns the appropriate slot for it in
81  * the bo_labels[] array, extending it as necessary.
82  *
83  * This is inefficient and could use a hash table instead of walking
84  * an array and strcmp()ing.  However, the assumption is that user
85  * labeling will be infrequent (scanout buffers and other long-lived
86  * objects, or debug driver builds), so we can live with it for now.
87  */
88 static int vc4_get_user_label(struct vc4_dev *vc4, const char *name)
89 {
90 	int i;
91 	int free_slot = -1;
92 
93 	for (i = 0; i < vc4->num_labels; i++) {
94 		if (!vc4->bo_labels[i].name) {
95 			free_slot = i;
96 		} else if (strcmp(vc4->bo_labels[i].name, name) == 0) {
97 			kfree(name);
98 			return i;
99 		}
100 	}
101 
102 	if (free_slot != -1) {
103 		WARN_ON(vc4->bo_labels[free_slot].num_allocated != 0);
104 		vc4->bo_labels[free_slot].name = name;
105 		return free_slot;
106 	} else {
107 		u32 new_label_count = vc4->num_labels + 1;
108 		struct vc4_label *new_labels =
109 			krealloc(vc4->bo_labels,
110 				 new_label_count * sizeof(*new_labels),
111 				 GFP_KERNEL);
112 
113 		if (!new_labels) {
114 			kfree(name);
115 			return -1;
116 		}
117 
118 		free_slot = vc4->num_labels;
119 		vc4->bo_labels = new_labels;
120 		vc4->num_labels = new_label_count;
121 
122 		vc4->bo_labels[free_slot].name = name;
123 		vc4->bo_labels[free_slot].num_allocated = 0;
124 		vc4->bo_labels[free_slot].size_allocated = 0;
125 
126 		return free_slot;
127 	}
128 }
129 
130 static void vc4_bo_set_label(struct drm_gem_object *gem_obj, int label)
131 {
132 	struct vc4_bo *bo = to_vc4_bo(gem_obj);
133 	struct vc4_dev *vc4 = to_vc4_dev(gem_obj->dev);
134 
135 	lockdep_assert_held(&vc4->bo_lock);
136 
137 	if (label != -1) {
138 		vc4->bo_labels[label].num_allocated++;
139 		vc4->bo_labels[label].size_allocated += gem_obj->size;
140 	}
141 
142 	vc4->bo_labels[bo->label].num_allocated--;
143 	vc4->bo_labels[bo->label].size_allocated -= gem_obj->size;
144 
145 	if (vc4->bo_labels[bo->label].num_allocated == 0 &&
146 	    is_user_label(bo->label)) {
147 		/* Free user BO label slots on last unreference.
148 		 * Slots are just where we track the stats for a given
149 		 * name, and once a name is unused we can reuse that
150 		 * slot.
151 		 */
152 		kfree(vc4->bo_labels[bo->label].name);
153 		vc4->bo_labels[bo->label].name = NULL;
154 	}
155 
156 	bo->label = label;
157 }
158 
159 static uint32_t bo_page_index(size_t size)
160 {
161 	return (size / PAGE_SIZE) - 1;
162 }
163 
164 static void vc4_bo_destroy(struct vc4_bo *bo)
165 {
166 	struct drm_gem_object *obj = &bo->base.base;
167 	struct vc4_dev *vc4 = to_vc4_dev(obj->dev);
168 
169 	lockdep_assert_held(&vc4->bo_lock);
170 
171 	vc4_bo_set_label(obj, -1);
172 
173 	if (bo->validated_shader) {
174 		kfree(bo->validated_shader->uniform_addr_offsets);
175 		kfree(bo->validated_shader->texture_samples);
176 		kfree(bo->validated_shader);
177 		bo->validated_shader = NULL;
178 	}
179 
180 	drm_gem_cma_free(&bo->base);
181 }
182 
183 static void vc4_bo_remove_from_cache(struct vc4_bo *bo)
184 {
185 	struct vc4_dev *vc4 = to_vc4_dev(bo->base.base.dev);
186 
187 	lockdep_assert_held(&vc4->bo_lock);
188 	list_del(&bo->unref_head);
189 	list_del(&bo->size_head);
190 }
191 
192 static struct list_head *vc4_get_cache_list_for_size(struct drm_device *dev,
193 						     size_t size)
194 {
195 	struct vc4_dev *vc4 = to_vc4_dev(dev);
196 	uint32_t page_index = bo_page_index(size);
197 
198 	if (vc4->bo_cache.size_list_size <= page_index) {
199 		uint32_t new_size = max(vc4->bo_cache.size_list_size * 2,
200 					page_index + 1);
201 		struct list_head *new_list;
202 		uint32_t i;
203 
204 		new_list = kmalloc_array(new_size, sizeof(struct list_head),
205 					 GFP_KERNEL);
206 		if (!new_list)
207 			return NULL;
208 
209 		/* Rebase the old cached BO lists to their new list
210 		 * head locations.
211 		 */
212 		for (i = 0; i < vc4->bo_cache.size_list_size; i++) {
213 			struct list_head *old_list =
214 				&vc4->bo_cache.size_list[i];
215 
216 			if (list_empty(old_list))
217 				INIT_LIST_HEAD(&new_list[i]);
218 			else
219 				list_replace(old_list, &new_list[i]);
220 		}
221 		/* And initialize the brand new BO list heads. */
222 		for (i = vc4->bo_cache.size_list_size; i < new_size; i++)
223 			INIT_LIST_HEAD(&new_list[i]);
224 
225 		kfree(vc4->bo_cache.size_list);
226 		vc4->bo_cache.size_list = new_list;
227 		vc4->bo_cache.size_list_size = new_size;
228 	}
229 
230 	return &vc4->bo_cache.size_list[page_index];
231 }
232 
233 static void vc4_bo_cache_purge(struct drm_device *dev)
234 {
235 	struct vc4_dev *vc4 = to_vc4_dev(dev);
236 
237 	mutex_lock(&vc4->bo_lock);
238 	while (!list_empty(&vc4->bo_cache.time_list)) {
239 		struct vc4_bo *bo = list_last_entry(&vc4->bo_cache.time_list,
240 						    struct vc4_bo, unref_head);
241 		vc4_bo_remove_from_cache(bo);
242 		vc4_bo_destroy(bo);
243 	}
244 	mutex_unlock(&vc4->bo_lock);
245 }
246 
247 void vc4_bo_add_to_purgeable_pool(struct vc4_bo *bo)
248 {
249 	struct vc4_dev *vc4 = to_vc4_dev(bo->base.base.dev);
250 
251 	if (WARN_ON_ONCE(vc4->is_vc5))
252 		return;
253 
254 	mutex_lock(&vc4->purgeable.lock);
255 	list_add_tail(&bo->size_head, &vc4->purgeable.list);
256 	vc4->purgeable.num++;
257 	vc4->purgeable.size += bo->base.base.size;
258 	mutex_unlock(&vc4->purgeable.lock);
259 }
260 
261 static void vc4_bo_remove_from_purgeable_pool_locked(struct vc4_bo *bo)
262 {
263 	struct vc4_dev *vc4 = to_vc4_dev(bo->base.base.dev);
264 
265 	if (WARN_ON_ONCE(vc4->is_vc5))
266 		return;
267 
268 	/* list_del_init() is used here because the caller might release
269 	 * the purgeable lock in order to acquire the madv one and update the
270 	 * madv status.
271 	 * During this short period of time a user might decide to mark
272 	 * the BO as unpurgeable, and if bo->madv is set to
273 	 * VC4_MADV_DONTNEED it will try to remove the BO from the
274 	 * purgeable list which will fail if the ->next/prev fields
275 	 * are set to LIST_POISON1/LIST_POISON2 (which is what
276 	 * list_del() does).
277 	 * Re-initializing the list element guarantees that list_del()
278 	 * will work correctly even if it's a NOP.
279 	 */
280 	list_del_init(&bo->size_head);
281 	vc4->purgeable.num--;
282 	vc4->purgeable.size -= bo->base.base.size;
283 }
284 
285 void vc4_bo_remove_from_purgeable_pool(struct vc4_bo *bo)
286 {
287 	struct vc4_dev *vc4 = to_vc4_dev(bo->base.base.dev);
288 
289 	mutex_lock(&vc4->purgeable.lock);
290 	vc4_bo_remove_from_purgeable_pool_locked(bo);
291 	mutex_unlock(&vc4->purgeable.lock);
292 }
293 
294 static void vc4_bo_purge(struct drm_gem_object *obj)
295 {
296 	struct vc4_bo *bo = to_vc4_bo(obj);
297 	struct drm_device *dev = obj->dev;
298 
299 	WARN_ON(!mutex_is_locked(&bo->madv_lock));
300 	WARN_ON(bo->madv != VC4_MADV_DONTNEED);
301 
302 	drm_vma_node_unmap(&obj->vma_node, dev->anon_inode->i_mapping);
303 
304 	dma_free_wc(dev->dev, obj->size, bo->base.vaddr, bo->base.paddr);
305 	bo->base.vaddr = NULL;
306 	bo->madv = __VC4_MADV_PURGED;
307 }
308 
309 static void vc4_bo_userspace_cache_purge(struct drm_device *dev)
310 {
311 	struct vc4_dev *vc4 = to_vc4_dev(dev);
312 
313 	mutex_lock(&vc4->purgeable.lock);
314 	while (!list_empty(&vc4->purgeable.list)) {
315 		struct vc4_bo *bo = list_first_entry(&vc4->purgeable.list,
316 						     struct vc4_bo, size_head);
317 		struct drm_gem_object *obj = &bo->base.base;
318 		size_t purged_size = 0;
319 
320 		vc4_bo_remove_from_purgeable_pool_locked(bo);
321 
322 		/* Release the purgeable lock while we're purging the BO so
323 		 * that other people can continue inserting things in the
324 		 * purgeable pool without having to wait for all BOs to be
325 		 * purged.
326 		 */
327 		mutex_unlock(&vc4->purgeable.lock);
328 		mutex_lock(&bo->madv_lock);
329 
330 		/* Since we released the purgeable pool lock before acquiring
331 		 * the BO madv one, the user may have marked the BO as WILLNEED
332 		 * and re-used it in the meantime.
333 		 * Before purging the BO we need to make sure
334 		 * - it is still marked as DONTNEED
335 		 * - it has not been re-inserted in the purgeable list
336 		 * - it is not used by HW blocks
337 		 * If one of these conditions is not met, just skip the entry.
338 		 */
339 		if (bo->madv == VC4_MADV_DONTNEED &&
340 		    list_empty(&bo->size_head) &&
341 		    !refcount_read(&bo->usecnt)) {
342 			purged_size = bo->base.base.size;
343 			vc4_bo_purge(obj);
344 		}
345 		mutex_unlock(&bo->madv_lock);
346 		mutex_lock(&vc4->purgeable.lock);
347 
348 		if (purged_size) {
349 			vc4->purgeable.purged_size += purged_size;
350 			vc4->purgeable.purged_num++;
351 		}
352 	}
353 	mutex_unlock(&vc4->purgeable.lock);
354 }
355 
356 static struct vc4_bo *vc4_bo_get_from_cache(struct drm_device *dev,
357 					    uint32_t size,
358 					    enum vc4_kernel_bo_type type)
359 {
360 	struct vc4_dev *vc4 = to_vc4_dev(dev);
361 	uint32_t page_index = bo_page_index(size);
362 	struct vc4_bo *bo = NULL;
363 
364 	mutex_lock(&vc4->bo_lock);
365 	if (page_index >= vc4->bo_cache.size_list_size)
366 		goto out;
367 
368 	if (list_empty(&vc4->bo_cache.size_list[page_index]))
369 		goto out;
370 
371 	bo = list_first_entry(&vc4->bo_cache.size_list[page_index],
372 			      struct vc4_bo, size_head);
373 	vc4_bo_remove_from_cache(bo);
374 	kref_init(&bo->base.base.refcount);
375 
376 out:
377 	if (bo)
378 		vc4_bo_set_label(&bo->base.base, type);
379 	mutex_unlock(&vc4->bo_lock);
380 	return bo;
381 }
382 
383 /**
384  * vc4_create_object - Implementation of driver->gem_create_object.
385  * @dev: DRM device
386  * @size: Size in bytes of the memory the object will reference
387  *
388  * This lets the CMA helpers allocate object structs for us, and keep
389  * our BO stats correct.
390  */
391 struct drm_gem_object *vc4_create_object(struct drm_device *dev, size_t size)
392 {
393 	struct vc4_dev *vc4 = to_vc4_dev(dev);
394 	struct vc4_bo *bo;
395 
396 	if (WARN_ON_ONCE(vc4->is_vc5))
397 		return ERR_PTR(-ENODEV);
398 
399 	bo = kzalloc(sizeof(*bo), GFP_KERNEL);
400 	if (!bo)
401 		return ERR_PTR(-ENOMEM);
402 
403 	bo->madv = VC4_MADV_WILLNEED;
404 	refcount_set(&bo->usecnt, 0);
405 	mutex_init(&bo->madv_lock);
406 	mutex_lock(&vc4->bo_lock);
407 	bo->label = VC4_BO_TYPE_KERNEL;
408 	vc4->bo_labels[VC4_BO_TYPE_KERNEL].num_allocated++;
409 	vc4->bo_labels[VC4_BO_TYPE_KERNEL].size_allocated += size;
410 	mutex_unlock(&vc4->bo_lock);
411 
412 	bo->base.base.funcs = &vc4_gem_object_funcs;
413 
414 	return &bo->base.base;
415 }
416 
417 struct vc4_bo *vc4_bo_create(struct drm_device *dev, size_t unaligned_size,
418 			     bool allow_unzeroed, enum vc4_kernel_bo_type type)
419 {
420 	size_t size = roundup(unaligned_size, PAGE_SIZE);
421 	struct vc4_dev *vc4 = to_vc4_dev(dev);
422 	struct drm_gem_cma_object *cma_obj;
423 	struct vc4_bo *bo;
424 
425 	if (WARN_ON_ONCE(vc4->is_vc5))
426 		return ERR_PTR(-ENODEV);
427 
428 	if (size == 0)
429 		return ERR_PTR(-EINVAL);
430 
431 	/* First, try to get a vc4_bo from the kernel BO cache. */
432 	bo = vc4_bo_get_from_cache(dev, size, type);
433 	if (bo) {
434 		if (!allow_unzeroed)
435 			memset(bo->base.vaddr, 0, bo->base.base.size);
436 		return bo;
437 	}
438 
439 	cma_obj = drm_gem_cma_create(dev, size);
440 	if (IS_ERR(cma_obj)) {
441 		/*
442 		 * If we've run out of CMA memory, kill the cache of
443 		 * CMA allocations we've got laying around and try again.
444 		 */
445 		vc4_bo_cache_purge(dev);
446 		cma_obj = drm_gem_cma_create(dev, size);
447 	}
448 
449 	if (IS_ERR(cma_obj)) {
450 		/*
451 		 * Still not enough CMA memory, purge the userspace BO
452 		 * cache and retry.
453 		 * This is sub-optimal since we purge the whole userspace
454 		 * BO cache which forces user that want to re-use the BO to
455 		 * restore its initial content.
456 		 * Ideally, we should purge entries one by one and retry
457 		 * after each to see if CMA allocation succeeds. Or even
458 		 * better, try to find an entry with at least the same
459 		 * size.
460 		 */
461 		vc4_bo_userspace_cache_purge(dev);
462 		cma_obj = drm_gem_cma_create(dev, size);
463 	}
464 
465 	if (IS_ERR(cma_obj)) {
466 		struct drm_printer p = drm_info_printer(vc4->base.dev);
467 		DRM_ERROR("Failed to allocate from CMA:\n");
468 		vc4_bo_stats_print(&p, vc4);
469 		return ERR_PTR(-ENOMEM);
470 	}
471 	bo = to_vc4_bo(&cma_obj->base);
472 
473 	/* By default, BOs do not support the MADV ioctl. This will be enabled
474 	 * only on BOs that are exposed to userspace (V3D, V3D_SHADER and DUMB
475 	 * BOs).
476 	 */
477 	bo->madv = __VC4_MADV_NOTSUPP;
478 
479 	mutex_lock(&vc4->bo_lock);
480 	vc4_bo_set_label(&cma_obj->base, type);
481 	mutex_unlock(&vc4->bo_lock);
482 
483 	return bo;
484 }
485 
486 int vc4_bo_dumb_create(struct drm_file *file_priv,
487 		       struct drm_device *dev,
488 		       struct drm_mode_create_dumb *args)
489 {
490 	struct vc4_dev *vc4 = to_vc4_dev(dev);
491 	struct vc4_bo *bo = NULL;
492 	int ret;
493 
494 	if (WARN_ON_ONCE(vc4->is_vc5))
495 		return -ENODEV;
496 
497 	ret = vc4_dumb_fixup_args(args);
498 	if (ret)
499 		return ret;
500 
501 	bo = vc4_bo_create(dev, args->size, false, VC4_BO_TYPE_DUMB);
502 	if (IS_ERR(bo))
503 		return PTR_ERR(bo);
504 
505 	bo->madv = VC4_MADV_WILLNEED;
506 
507 	ret = drm_gem_handle_create(file_priv, &bo->base.base, &args->handle);
508 	drm_gem_object_put(&bo->base.base);
509 
510 	return ret;
511 }
512 
513 static void vc4_bo_cache_free_old(struct drm_device *dev)
514 {
515 	struct vc4_dev *vc4 = to_vc4_dev(dev);
516 	unsigned long expire_time = jiffies - msecs_to_jiffies(1000);
517 
518 	lockdep_assert_held(&vc4->bo_lock);
519 
520 	while (!list_empty(&vc4->bo_cache.time_list)) {
521 		struct vc4_bo *bo = list_last_entry(&vc4->bo_cache.time_list,
522 						    struct vc4_bo, unref_head);
523 		if (time_before(expire_time, bo->free_time)) {
524 			mod_timer(&vc4->bo_cache.time_timer,
525 				  round_jiffies_up(jiffies +
526 						   msecs_to_jiffies(1000)));
527 			return;
528 		}
529 
530 		vc4_bo_remove_from_cache(bo);
531 		vc4_bo_destroy(bo);
532 	}
533 }
534 
535 /* Called on the last userspace/kernel unreference of the BO.  Returns
536  * it to the BO cache if possible, otherwise frees it.
537  */
538 static void vc4_free_object(struct drm_gem_object *gem_bo)
539 {
540 	struct drm_device *dev = gem_bo->dev;
541 	struct vc4_dev *vc4 = to_vc4_dev(dev);
542 	struct vc4_bo *bo = to_vc4_bo(gem_bo);
543 	struct list_head *cache_list;
544 
545 	/* Remove the BO from the purgeable list. */
546 	mutex_lock(&bo->madv_lock);
547 	if (bo->madv == VC4_MADV_DONTNEED && !refcount_read(&bo->usecnt))
548 		vc4_bo_remove_from_purgeable_pool(bo);
549 	mutex_unlock(&bo->madv_lock);
550 
551 	mutex_lock(&vc4->bo_lock);
552 	/* If the object references someone else's memory, we can't cache it.
553 	 */
554 	if (gem_bo->import_attach) {
555 		vc4_bo_destroy(bo);
556 		goto out;
557 	}
558 
559 	/* Don't cache if it was publicly named. */
560 	if (gem_bo->name) {
561 		vc4_bo_destroy(bo);
562 		goto out;
563 	}
564 
565 	/* If this object was partially constructed but CMA allocation
566 	 * had failed, just free it. Can also happen when the BO has been
567 	 * purged.
568 	 */
569 	if (!bo->base.vaddr) {
570 		vc4_bo_destroy(bo);
571 		goto out;
572 	}
573 
574 	cache_list = vc4_get_cache_list_for_size(dev, gem_bo->size);
575 	if (!cache_list) {
576 		vc4_bo_destroy(bo);
577 		goto out;
578 	}
579 
580 	if (bo->validated_shader) {
581 		kfree(bo->validated_shader->uniform_addr_offsets);
582 		kfree(bo->validated_shader->texture_samples);
583 		kfree(bo->validated_shader);
584 		bo->validated_shader = NULL;
585 	}
586 
587 	/* Reset madv and usecnt before adding the BO to the cache. */
588 	bo->madv = __VC4_MADV_NOTSUPP;
589 	refcount_set(&bo->usecnt, 0);
590 
591 	bo->t_format = false;
592 	bo->free_time = jiffies;
593 	list_add(&bo->size_head, cache_list);
594 	list_add(&bo->unref_head, &vc4->bo_cache.time_list);
595 
596 	vc4_bo_set_label(&bo->base.base, VC4_BO_TYPE_KERNEL_CACHE);
597 
598 	vc4_bo_cache_free_old(dev);
599 
600 out:
601 	mutex_unlock(&vc4->bo_lock);
602 }
603 
604 static void vc4_bo_cache_time_work(struct work_struct *work)
605 {
606 	struct vc4_dev *vc4 =
607 		container_of(work, struct vc4_dev, bo_cache.time_work);
608 	struct drm_device *dev = &vc4->base;
609 
610 	mutex_lock(&vc4->bo_lock);
611 	vc4_bo_cache_free_old(dev);
612 	mutex_unlock(&vc4->bo_lock);
613 }
614 
615 int vc4_bo_inc_usecnt(struct vc4_bo *bo)
616 {
617 	struct vc4_dev *vc4 = to_vc4_dev(bo->base.base.dev);
618 	int ret;
619 
620 	if (WARN_ON_ONCE(vc4->is_vc5))
621 		return -ENODEV;
622 
623 	/* Fast path: if the BO is already retained by someone, no need to
624 	 * check the madv status.
625 	 */
626 	if (refcount_inc_not_zero(&bo->usecnt))
627 		return 0;
628 
629 	mutex_lock(&bo->madv_lock);
630 	switch (bo->madv) {
631 	case VC4_MADV_WILLNEED:
632 		if (!refcount_inc_not_zero(&bo->usecnt))
633 			refcount_set(&bo->usecnt, 1);
634 		ret = 0;
635 		break;
636 	case VC4_MADV_DONTNEED:
637 		/* We shouldn't use a BO marked as purgeable if at least
638 		 * someone else retained its content by incrementing usecnt.
639 		 * Luckily the BO hasn't been purged yet, but something wrong
640 		 * is happening here. Just throw an error instead of
641 		 * authorizing this use case.
642 		 */
643 	case __VC4_MADV_PURGED:
644 		/* We can't use a purged BO. */
645 	default:
646 		/* Invalid madv value. */
647 		ret = -EINVAL;
648 		break;
649 	}
650 	mutex_unlock(&bo->madv_lock);
651 
652 	return ret;
653 }
654 
655 void vc4_bo_dec_usecnt(struct vc4_bo *bo)
656 {
657 	struct vc4_dev *vc4 = to_vc4_dev(bo->base.base.dev);
658 
659 	if (WARN_ON_ONCE(vc4->is_vc5))
660 		return;
661 
662 	/* Fast path: if the BO is still retained by someone, no need to test
663 	 * the madv value.
664 	 */
665 	if (refcount_dec_not_one(&bo->usecnt))
666 		return;
667 
668 	mutex_lock(&bo->madv_lock);
669 	if (refcount_dec_and_test(&bo->usecnt) &&
670 	    bo->madv == VC4_MADV_DONTNEED)
671 		vc4_bo_add_to_purgeable_pool(bo);
672 	mutex_unlock(&bo->madv_lock);
673 }
674 
675 static void vc4_bo_cache_time_timer(struct timer_list *t)
676 {
677 	struct vc4_dev *vc4 = from_timer(vc4, t, bo_cache.time_timer);
678 
679 	schedule_work(&vc4->bo_cache.time_work);
680 }
681 
682 static struct dma_buf *vc4_prime_export(struct drm_gem_object *obj, int flags)
683 {
684 	struct vc4_bo *bo = to_vc4_bo(obj);
685 	struct dma_buf *dmabuf;
686 	int ret;
687 
688 	if (bo->validated_shader) {
689 		DRM_DEBUG("Attempting to export shader BO\n");
690 		return ERR_PTR(-EINVAL);
691 	}
692 
693 	/* Note: as soon as the BO is exported it becomes unpurgeable, because
694 	 * noone ever decrements the usecnt even if the reference held by the
695 	 * exported BO is released. This shouldn't be a problem since we don't
696 	 * expect exported BOs to be marked as purgeable.
697 	 */
698 	ret = vc4_bo_inc_usecnt(bo);
699 	if (ret) {
700 		DRM_ERROR("Failed to increment BO usecnt\n");
701 		return ERR_PTR(ret);
702 	}
703 
704 	dmabuf = drm_gem_prime_export(obj, flags);
705 	if (IS_ERR(dmabuf))
706 		vc4_bo_dec_usecnt(bo);
707 
708 	return dmabuf;
709 }
710 
711 static vm_fault_t vc4_fault(struct vm_fault *vmf)
712 {
713 	struct vm_area_struct *vma = vmf->vma;
714 	struct drm_gem_object *obj = vma->vm_private_data;
715 	struct vc4_bo *bo = to_vc4_bo(obj);
716 
717 	/* The only reason we would end up here is when user-space accesses
718 	 * BO's memory after it's been purged.
719 	 */
720 	mutex_lock(&bo->madv_lock);
721 	WARN_ON(bo->madv != __VC4_MADV_PURGED);
722 	mutex_unlock(&bo->madv_lock);
723 
724 	return VM_FAULT_SIGBUS;
725 }
726 
727 static int vc4_gem_object_mmap(struct drm_gem_object *obj, struct vm_area_struct *vma)
728 {
729 	struct vc4_bo *bo = to_vc4_bo(obj);
730 
731 	if (bo->validated_shader && (vma->vm_flags & VM_WRITE)) {
732 		DRM_DEBUG("mmaping of shader BOs for writing not allowed.\n");
733 		return -EINVAL;
734 	}
735 
736 	if (bo->madv != VC4_MADV_WILLNEED) {
737 		DRM_DEBUG("mmaping of %s BO not allowed\n",
738 			  bo->madv == VC4_MADV_DONTNEED ?
739 			  "purgeable" : "purged");
740 		return -EINVAL;
741 	}
742 
743 	return drm_gem_cma_mmap(&bo->base, vma);
744 }
745 
746 static const struct vm_operations_struct vc4_vm_ops = {
747 	.fault = vc4_fault,
748 	.open = drm_gem_vm_open,
749 	.close = drm_gem_vm_close,
750 };
751 
752 static const struct drm_gem_object_funcs vc4_gem_object_funcs = {
753 	.free = vc4_free_object,
754 	.export = vc4_prime_export,
755 	.get_sg_table = drm_gem_cma_object_get_sg_table,
756 	.vmap = drm_gem_cma_object_vmap,
757 	.mmap = vc4_gem_object_mmap,
758 	.vm_ops = &vc4_vm_ops,
759 };
760 
761 static int vc4_grab_bin_bo(struct vc4_dev *vc4, struct vc4_file *vc4file)
762 {
763 	if (!vc4->v3d)
764 		return -ENODEV;
765 
766 	if (vc4file->bin_bo_used)
767 		return 0;
768 
769 	return vc4_v3d_bin_bo_get(vc4, &vc4file->bin_bo_used);
770 }
771 
772 int vc4_create_bo_ioctl(struct drm_device *dev, void *data,
773 			struct drm_file *file_priv)
774 {
775 	struct drm_vc4_create_bo *args = data;
776 	struct vc4_file *vc4file = file_priv->driver_priv;
777 	struct vc4_dev *vc4 = to_vc4_dev(dev);
778 	struct vc4_bo *bo = NULL;
779 	int ret;
780 
781 	if (WARN_ON_ONCE(vc4->is_vc5))
782 		return -ENODEV;
783 
784 	ret = vc4_grab_bin_bo(vc4, vc4file);
785 	if (ret)
786 		return ret;
787 
788 	/*
789 	 * We can't allocate from the BO cache, because the BOs don't
790 	 * get zeroed, and that might leak data between users.
791 	 */
792 	bo = vc4_bo_create(dev, args->size, false, VC4_BO_TYPE_V3D);
793 	if (IS_ERR(bo))
794 		return PTR_ERR(bo);
795 
796 	bo->madv = VC4_MADV_WILLNEED;
797 
798 	ret = drm_gem_handle_create(file_priv, &bo->base.base, &args->handle);
799 	drm_gem_object_put(&bo->base.base);
800 
801 	return ret;
802 }
803 
804 int vc4_mmap_bo_ioctl(struct drm_device *dev, void *data,
805 		      struct drm_file *file_priv)
806 {
807 	struct vc4_dev *vc4 = to_vc4_dev(dev);
808 	struct drm_vc4_mmap_bo *args = data;
809 	struct drm_gem_object *gem_obj;
810 
811 	if (WARN_ON_ONCE(vc4->is_vc5))
812 		return -ENODEV;
813 
814 	gem_obj = drm_gem_object_lookup(file_priv, args->handle);
815 	if (!gem_obj) {
816 		DRM_DEBUG("Failed to look up GEM BO %d\n", args->handle);
817 		return -EINVAL;
818 	}
819 
820 	/* The mmap offset was set up at BO allocation time. */
821 	args->offset = drm_vma_node_offset_addr(&gem_obj->vma_node);
822 
823 	drm_gem_object_put(gem_obj);
824 	return 0;
825 }
826 
827 int
828 vc4_create_shader_bo_ioctl(struct drm_device *dev, void *data,
829 			   struct drm_file *file_priv)
830 {
831 	struct drm_vc4_create_shader_bo *args = data;
832 	struct vc4_file *vc4file = file_priv->driver_priv;
833 	struct vc4_dev *vc4 = to_vc4_dev(dev);
834 	struct vc4_bo *bo = NULL;
835 	int ret;
836 
837 	if (WARN_ON_ONCE(vc4->is_vc5))
838 		return -ENODEV;
839 
840 	if (args->size == 0)
841 		return -EINVAL;
842 
843 	if (args->size % sizeof(u64) != 0)
844 		return -EINVAL;
845 
846 	if (args->flags != 0) {
847 		DRM_INFO("Unknown flags set: 0x%08x\n", args->flags);
848 		return -EINVAL;
849 	}
850 
851 	if (args->pad != 0) {
852 		DRM_INFO("Pad set: 0x%08x\n", args->pad);
853 		return -EINVAL;
854 	}
855 
856 	ret = vc4_grab_bin_bo(vc4, vc4file);
857 	if (ret)
858 		return ret;
859 
860 	bo = vc4_bo_create(dev, args->size, true, VC4_BO_TYPE_V3D_SHADER);
861 	if (IS_ERR(bo))
862 		return PTR_ERR(bo);
863 
864 	bo->madv = VC4_MADV_WILLNEED;
865 
866 	if (copy_from_user(bo->base.vaddr,
867 			     (void __user *)(uintptr_t)args->data,
868 			     args->size)) {
869 		ret = -EFAULT;
870 		goto fail;
871 	}
872 	/* Clear the rest of the memory from allocating from the BO
873 	 * cache.
874 	 */
875 	memset(bo->base.vaddr + args->size, 0,
876 	       bo->base.base.size - args->size);
877 
878 	bo->validated_shader = vc4_validate_shader(&bo->base);
879 	if (!bo->validated_shader) {
880 		ret = -EINVAL;
881 		goto fail;
882 	}
883 
884 	/* We have to create the handle after validation, to avoid
885 	 * races for users to do doing things like mmap the shader BO.
886 	 */
887 	ret = drm_gem_handle_create(file_priv, &bo->base.base, &args->handle);
888 
889 fail:
890 	drm_gem_object_put(&bo->base.base);
891 
892 	return ret;
893 }
894 
895 /**
896  * vc4_set_tiling_ioctl() - Sets the tiling modifier for a BO.
897  * @dev: DRM device
898  * @data: ioctl argument
899  * @file_priv: DRM file for this fd
900  *
901  * The tiling state of the BO decides the default modifier of an fb if
902  * no specific modifier was set by userspace, and the return value of
903  * vc4_get_tiling_ioctl() (so that userspace can treat a BO it
904  * received from dmabuf as the same tiling format as the producer
905  * used).
906  */
907 int vc4_set_tiling_ioctl(struct drm_device *dev, void *data,
908 			 struct drm_file *file_priv)
909 {
910 	struct vc4_dev *vc4 = to_vc4_dev(dev);
911 	struct drm_vc4_set_tiling *args = data;
912 	struct drm_gem_object *gem_obj;
913 	struct vc4_bo *bo;
914 	bool t_format;
915 
916 	if (WARN_ON_ONCE(vc4->is_vc5))
917 		return -ENODEV;
918 
919 	if (args->flags != 0)
920 		return -EINVAL;
921 
922 	switch (args->modifier) {
923 	case DRM_FORMAT_MOD_NONE:
924 		t_format = false;
925 		break;
926 	case DRM_FORMAT_MOD_BROADCOM_VC4_T_TILED:
927 		t_format = true;
928 		break;
929 	default:
930 		return -EINVAL;
931 	}
932 
933 	gem_obj = drm_gem_object_lookup(file_priv, args->handle);
934 	if (!gem_obj) {
935 		DRM_DEBUG("Failed to look up GEM BO %d\n", args->handle);
936 		return -ENOENT;
937 	}
938 	bo = to_vc4_bo(gem_obj);
939 	bo->t_format = t_format;
940 
941 	drm_gem_object_put(gem_obj);
942 
943 	return 0;
944 }
945 
946 /**
947  * vc4_get_tiling_ioctl() - Gets the tiling modifier for a BO.
948  * @dev: DRM device
949  * @data: ioctl argument
950  * @file_priv: DRM file for this fd
951  *
952  * Returns the tiling modifier for a BO as set by vc4_set_tiling_ioctl().
953  */
954 int vc4_get_tiling_ioctl(struct drm_device *dev, void *data,
955 			 struct drm_file *file_priv)
956 {
957 	struct vc4_dev *vc4 = to_vc4_dev(dev);
958 	struct drm_vc4_get_tiling *args = data;
959 	struct drm_gem_object *gem_obj;
960 	struct vc4_bo *bo;
961 
962 	if (WARN_ON_ONCE(vc4->is_vc5))
963 		return -ENODEV;
964 
965 	if (args->flags != 0 || args->modifier != 0)
966 		return -EINVAL;
967 
968 	gem_obj = drm_gem_object_lookup(file_priv, args->handle);
969 	if (!gem_obj) {
970 		DRM_DEBUG("Failed to look up GEM BO %d\n", args->handle);
971 		return -ENOENT;
972 	}
973 	bo = to_vc4_bo(gem_obj);
974 
975 	if (bo->t_format)
976 		args->modifier = DRM_FORMAT_MOD_BROADCOM_VC4_T_TILED;
977 	else
978 		args->modifier = DRM_FORMAT_MOD_NONE;
979 
980 	drm_gem_object_put(gem_obj);
981 
982 	return 0;
983 }
984 
985 static void vc4_bo_cache_destroy(struct drm_device *dev, void *unused);
986 int vc4_bo_cache_init(struct drm_device *dev)
987 {
988 	struct vc4_dev *vc4 = to_vc4_dev(dev);
989 	int i;
990 
991 	if (WARN_ON_ONCE(vc4->is_vc5))
992 		return -ENODEV;
993 
994 	/* Create the initial set of BO labels that the kernel will
995 	 * use.  This lets us avoid a bunch of string reallocation in
996 	 * the kernel's draw and BO allocation paths.
997 	 */
998 	vc4->bo_labels = kcalloc(VC4_BO_TYPE_COUNT, sizeof(*vc4->bo_labels),
999 				 GFP_KERNEL);
1000 	if (!vc4->bo_labels)
1001 		return -ENOMEM;
1002 	vc4->num_labels = VC4_BO_TYPE_COUNT;
1003 
1004 	BUILD_BUG_ON(ARRAY_SIZE(bo_type_names) != VC4_BO_TYPE_COUNT);
1005 	for (i = 0; i < VC4_BO_TYPE_COUNT; i++)
1006 		vc4->bo_labels[i].name = bo_type_names[i];
1007 
1008 	mutex_init(&vc4->bo_lock);
1009 
1010 	vc4_debugfs_add_file(dev, "bo_stats", vc4_bo_stats_debugfs, NULL);
1011 
1012 	INIT_LIST_HEAD(&vc4->bo_cache.time_list);
1013 
1014 	INIT_WORK(&vc4->bo_cache.time_work, vc4_bo_cache_time_work);
1015 	timer_setup(&vc4->bo_cache.time_timer, vc4_bo_cache_time_timer, 0);
1016 
1017 	return drmm_add_action_or_reset(dev, vc4_bo_cache_destroy, NULL);
1018 }
1019 
1020 static void vc4_bo_cache_destroy(struct drm_device *dev, void *unused)
1021 {
1022 	struct vc4_dev *vc4 = to_vc4_dev(dev);
1023 	int i;
1024 
1025 	del_timer(&vc4->bo_cache.time_timer);
1026 	cancel_work_sync(&vc4->bo_cache.time_work);
1027 
1028 	vc4_bo_cache_purge(dev);
1029 
1030 	for (i = 0; i < vc4->num_labels; i++) {
1031 		if (vc4->bo_labels[i].num_allocated) {
1032 			DRM_ERROR("Destroying BO cache with %d %s "
1033 				  "BOs still allocated\n",
1034 				  vc4->bo_labels[i].num_allocated,
1035 				  vc4->bo_labels[i].name);
1036 		}
1037 
1038 		if (is_user_label(i))
1039 			kfree(vc4->bo_labels[i].name);
1040 	}
1041 	kfree(vc4->bo_labels);
1042 }
1043 
1044 int vc4_label_bo_ioctl(struct drm_device *dev, void *data,
1045 		       struct drm_file *file_priv)
1046 {
1047 	struct vc4_dev *vc4 = to_vc4_dev(dev);
1048 	struct drm_vc4_label_bo *args = data;
1049 	char *name;
1050 	struct drm_gem_object *gem_obj;
1051 	int ret = 0, label;
1052 
1053 	if (WARN_ON_ONCE(vc4->is_vc5))
1054 		return -ENODEV;
1055 
1056 	if (!args->len)
1057 		return -EINVAL;
1058 
1059 	name = strndup_user(u64_to_user_ptr(args->name), args->len + 1);
1060 	if (IS_ERR(name))
1061 		return PTR_ERR(name);
1062 
1063 	gem_obj = drm_gem_object_lookup(file_priv, args->handle);
1064 	if (!gem_obj) {
1065 		DRM_ERROR("Failed to look up GEM BO %d\n", args->handle);
1066 		kfree(name);
1067 		return -ENOENT;
1068 	}
1069 
1070 	mutex_lock(&vc4->bo_lock);
1071 	label = vc4_get_user_label(vc4, name);
1072 	if (label != -1)
1073 		vc4_bo_set_label(gem_obj, label);
1074 	else
1075 		ret = -ENOMEM;
1076 	mutex_unlock(&vc4->bo_lock);
1077 
1078 	drm_gem_object_put(gem_obj);
1079 
1080 	return ret;
1081 }
1082