xref: /openbmc/linux/drivers/gpu/drm/vc4/vc4_bo.c (revision 2a9eb57e)
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 <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_info_node *node = (struct drm_info_node *)m->private;
73 	struct drm_device *dev = node->minor->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 	drm_gem_cma_free(&bo->base);
183 }
184 
185 static void vc4_bo_remove_from_cache(struct vc4_bo *bo)
186 {
187 	struct vc4_dev *vc4 = to_vc4_dev(bo->base.base.dev);
188 
189 	lockdep_assert_held(&vc4->bo_lock);
190 	list_del(&bo->unref_head);
191 	list_del(&bo->size_head);
192 }
193 
194 static struct list_head *vc4_get_cache_list_for_size(struct drm_device *dev,
195 						     size_t size)
196 {
197 	struct vc4_dev *vc4 = to_vc4_dev(dev);
198 	uint32_t page_index = bo_page_index(size);
199 
200 	if (vc4->bo_cache.size_list_size <= page_index) {
201 		uint32_t new_size = max(vc4->bo_cache.size_list_size * 2,
202 					page_index + 1);
203 		struct list_head *new_list;
204 		uint32_t i;
205 
206 		new_list = kmalloc_array(new_size, sizeof(struct list_head),
207 					 GFP_KERNEL);
208 		if (!new_list)
209 			return NULL;
210 
211 		/* Rebase the old cached BO lists to their new list
212 		 * head locations.
213 		 */
214 		for (i = 0; i < vc4->bo_cache.size_list_size; i++) {
215 			struct list_head *old_list =
216 				&vc4->bo_cache.size_list[i];
217 
218 			if (list_empty(old_list))
219 				INIT_LIST_HEAD(&new_list[i]);
220 			else
221 				list_replace(old_list, &new_list[i]);
222 		}
223 		/* And initialize the brand new BO list heads. */
224 		for (i = vc4->bo_cache.size_list_size; i < new_size; i++)
225 			INIT_LIST_HEAD(&new_list[i]);
226 
227 		kfree(vc4->bo_cache.size_list);
228 		vc4->bo_cache.size_list = new_list;
229 		vc4->bo_cache.size_list_size = new_size;
230 	}
231 
232 	return &vc4->bo_cache.size_list[page_index];
233 }
234 
235 static void vc4_bo_cache_purge(struct drm_device *dev)
236 {
237 	struct vc4_dev *vc4 = to_vc4_dev(dev);
238 
239 	mutex_lock(&vc4->bo_lock);
240 	while (!list_empty(&vc4->bo_cache.time_list)) {
241 		struct vc4_bo *bo = list_last_entry(&vc4->bo_cache.time_list,
242 						    struct vc4_bo, unref_head);
243 		vc4_bo_remove_from_cache(bo);
244 		vc4_bo_destroy(bo);
245 	}
246 	mutex_unlock(&vc4->bo_lock);
247 }
248 
249 void vc4_bo_add_to_purgeable_pool(struct vc4_bo *bo)
250 {
251 	struct vc4_dev *vc4 = to_vc4_dev(bo->base.base.dev);
252 
253 	if (WARN_ON_ONCE(vc4->is_vc5))
254 		return;
255 
256 	mutex_lock(&vc4->purgeable.lock);
257 	list_add_tail(&bo->size_head, &vc4->purgeable.list);
258 	vc4->purgeable.num++;
259 	vc4->purgeable.size += bo->base.base.size;
260 	mutex_unlock(&vc4->purgeable.lock);
261 }
262 
263 static void vc4_bo_remove_from_purgeable_pool_locked(struct vc4_bo *bo)
264 {
265 	struct vc4_dev *vc4 = to_vc4_dev(bo->base.base.dev);
266 
267 	if (WARN_ON_ONCE(vc4->is_vc5))
268 		return;
269 
270 	/* list_del_init() is used here because the caller might release
271 	 * the purgeable lock in order to acquire the madv one and update the
272 	 * madv status.
273 	 * During this short period of time a user might decide to mark
274 	 * the BO as unpurgeable, and if bo->madv is set to
275 	 * VC4_MADV_DONTNEED it will try to remove the BO from the
276 	 * purgeable list which will fail if the ->next/prev fields
277 	 * are set to LIST_POISON1/LIST_POISON2 (which is what
278 	 * list_del() does).
279 	 * Re-initializing the list element guarantees that list_del()
280 	 * will work correctly even if it's a NOP.
281 	 */
282 	list_del_init(&bo->size_head);
283 	vc4->purgeable.num--;
284 	vc4->purgeable.size -= bo->base.base.size;
285 }
286 
287 void vc4_bo_remove_from_purgeable_pool(struct vc4_bo *bo)
288 {
289 	struct vc4_dev *vc4 = to_vc4_dev(bo->base.base.dev);
290 
291 	mutex_lock(&vc4->purgeable.lock);
292 	vc4_bo_remove_from_purgeable_pool_locked(bo);
293 	mutex_unlock(&vc4->purgeable.lock);
294 }
295 
296 static void vc4_bo_purge(struct drm_gem_object *obj)
297 {
298 	struct vc4_bo *bo = to_vc4_bo(obj);
299 	struct drm_device *dev = obj->dev;
300 
301 	WARN_ON(!mutex_is_locked(&bo->madv_lock));
302 	WARN_ON(bo->madv != VC4_MADV_DONTNEED);
303 
304 	drm_vma_node_unmap(&obj->vma_node, dev->anon_inode->i_mapping);
305 
306 	dma_free_wc(dev->dev, obj->size, bo->base.vaddr, bo->base.paddr);
307 	bo->base.vaddr = NULL;
308 	bo->madv = __VC4_MADV_PURGED;
309 }
310 
311 static void vc4_bo_userspace_cache_purge(struct drm_device *dev)
312 {
313 	struct vc4_dev *vc4 = to_vc4_dev(dev);
314 
315 	mutex_lock(&vc4->purgeable.lock);
316 	while (!list_empty(&vc4->purgeable.list)) {
317 		struct vc4_bo *bo = list_first_entry(&vc4->purgeable.list,
318 						     struct vc4_bo, size_head);
319 		struct drm_gem_object *obj = &bo->base.base;
320 		size_t purged_size = 0;
321 
322 		vc4_bo_remove_from_purgeable_pool_locked(bo);
323 
324 		/* Release the purgeable lock while we're purging the BO so
325 		 * that other people can continue inserting things in the
326 		 * purgeable pool without having to wait for all BOs to be
327 		 * purged.
328 		 */
329 		mutex_unlock(&vc4->purgeable.lock);
330 		mutex_lock(&bo->madv_lock);
331 
332 		/* Since we released the purgeable pool lock before acquiring
333 		 * the BO madv one, the user may have marked the BO as WILLNEED
334 		 * and re-used it in the meantime.
335 		 * Before purging the BO we need to make sure
336 		 * - it is still marked as DONTNEED
337 		 * - it has not been re-inserted in the purgeable list
338 		 * - it is not used by HW blocks
339 		 * If one of these conditions is not met, just skip the entry.
340 		 */
341 		if (bo->madv == VC4_MADV_DONTNEED &&
342 		    list_empty(&bo->size_head) &&
343 		    !refcount_read(&bo->usecnt)) {
344 			purged_size = bo->base.base.size;
345 			vc4_bo_purge(obj);
346 		}
347 		mutex_unlock(&bo->madv_lock);
348 		mutex_lock(&vc4->purgeable.lock);
349 
350 		if (purged_size) {
351 			vc4->purgeable.purged_size += purged_size;
352 			vc4->purgeable.purged_num++;
353 		}
354 	}
355 	mutex_unlock(&vc4->purgeable.lock);
356 }
357 
358 static struct vc4_bo *vc4_bo_get_from_cache(struct drm_device *dev,
359 					    uint32_t size,
360 					    enum vc4_kernel_bo_type type)
361 {
362 	struct vc4_dev *vc4 = to_vc4_dev(dev);
363 	uint32_t page_index = bo_page_index(size);
364 	struct vc4_bo *bo = NULL;
365 
366 	mutex_lock(&vc4->bo_lock);
367 	if (page_index >= vc4->bo_cache.size_list_size)
368 		goto out;
369 
370 	if (list_empty(&vc4->bo_cache.size_list[page_index]))
371 		goto out;
372 
373 	bo = list_first_entry(&vc4->bo_cache.size_list[page_index],
374 			      struct vc4_bo, size_head);
375 	vc4_bo_remove_from_cache(bo);
376 	kref_init(&bo->base.base.refcount);
377 
378 out:
379 	if (bo)
380 		vc4_bo_set_label(&bo->base.base, type);
381 	mutex_unlock(&vc4->bo_lock);
382 	return bo;
383 }
384 
385 /**
386  * vc4_create_object - Implementation of driver->gem_create_object.
387  * @dev: DRM device
388  * @size: Size in bytes of the memory the object will reference
389  *
390  * This lets the CMA helpers allocate object structs for us, and keep
391  * our BO stats correct.
392  */
393 struct drm_gem_object *vc4_create_object(struct drm_device *dev, size_t size)
394 {
395 	struct vc4_dev *vc4 = to_vc4_dev(dev);
396 	struct vc4_bo *bo;
397 
398 	if (WARN_ON_ONCE(vc4->is_vc5))
399 		return ERR_PTR(-ENODEV);
400 
401 	bo = kzalloc(sizeof(*bo), GFP_KERNEL);
402 	if (!bo)
403 		return ERR_PTR(-ENOMEM);
404 
405 	bo->madv = VC4_MADV_WILLNEED;
406 	refcount_set(&bo->usecnt, 0);
407 	mutex_init(&bo->madv_lock);
408 	mutex_lock(&vc4->bo_lock);
409 	bo->label = VC4_BO_TYPE_KERNEL;
410 	vc4->bo_labels[VC4_BO_TYPE_KERNEL].num_allocated++;
411 	vc4->bo_labels[VC4_BO_TYPE_KERNEL].size_allocated += size;
412 	mutex_unlock(&vc4->bo_lock);
413 
414 	bo->base.base.funcs = &vc4_gem_object_funcs;
415 
416 	return &bo->base.base;
417 }
418 
419 struct vc4_bo *vc4_bo_create(struct drm_device *dev, size_t unaligned_size,
420 			     bool allow_unzeroed, enum vc4_kernel_bo_type type)
421 {
422 	size_t size = roundup(unaligned_size, PAGE_SIZE);
423 	struct vc4_dev *vc4 = to_vc4_dev(dev);
424 	struct drm_gem_cma_object *cma_obj;
425 	struct vc4_bo *bo;
426 
427 	if (WARN_ON_ONCE(vc4->is_vc5))
428 		return ERR_PTR(-ENODEV);
429 
430 	if (size == 0)
431 		return ERR_PTR(-EINVAL);
432 
433 	/* First, try to get a vc4_bo from the kernel BO cache. */
434 	bo = vc4_bo_get_from_cache(dev, size, type);
435 	if (bo) {
436 		if (!allow_unzeroed)
437 			memset(bo->base.vaddr, 0, bo->base.base.size);
438 		return bo;
439 	}
440 
441 	cma_obj = drm_gem_cma_create(dev, size);
442 	if (IS_ERR(cma_obj)) {
443 		/*
444 		 * If we've run out of CMA memory, kill the cache of
445 		 * CMA allocations we've got laying around and try again.
446 		 */
447 		vc4_bo_cache_purge(dev);
448 		cma_obj = drm_gem_cma_create(dev, size);
449 	}
450 
451 	if (IS_ERR(cma_obj)) {
452 		/*
453 		 * Still not enough CMA memory, purge the userspace BO
454 		 * cache and retry.
455 		 * This is sub-optimal since we purge the whole userspace
456 		 * BO cache which forces user that want to re-use the BO to
457 		 * restore its initial content.
458 		 * Ideally, we should purge entries one by one and retry
459 		 * after each to see if CMA allocation succeeds. Or even
460 		 * better, try to find an entry with at least the same
461 		 * size.
462 		 */
463 		vc4_bo_userspace_cache_purge(dev);
464 		cma_obj = drm_gem_cma_create(dev, size);
465 	}
466 
467 	if (IS_ERR(cma_obj)) {
468 		struct drm_printer p = drm_info_printer(vc4->base.dev);
469 		DRM_ERROR("Failed to allocate from CMA:\n");
470 		vc4_bo_stats_print(&p, vc4);
471 		return ERR_PTR(-ENOMEM);
472 	}
473 	bo = to_vc4_bo(&cma_obj->base);
474 
475 	/* By default, BOs do not support the MADV ioctl. This will be enabled
476 	 * only on BOs that are exposed to userspace (V3D, V3D_SHADER and DUMB
477 	 * BOs).
478 	 */
479 	bo->madv = __VC4_MADV_NOTSUPP;
480 
481 	mutex_lock(&vc4->bo_lock);
482 	vc4_bo_set_label(&cma_obj->base, type);
483 	mutex_unlock(&vc4->bo_lock);
484 
485 	return bo;
486 }
487 
488 int vc4_bo_dumb_create(struct drm_file *file_priv,
489 		       struct drm_device *dev,
490 		       struct drm_mode_create_dumb *args)
491 {
492 	struct vc4_dev *vc4 = to_vc4_dev(dev);
493 	struct vc4_bo *bo = NULL;
494 	int ret;
495 
496 	if (WARN_ON_ONCE(vc4->is_vc5))
497 		return -ENODEV;
498 
499 	ret = vc4_dumb_fixup_args(args);
500 	if (ret)
501 		return ret;
502 
503 	bo = vc4_bo_create(dev, args->size, false, VC4_BO_TYPE_DUMB);
504 	if (IS_ERR(bo))
505 		return PTR_ERR(bo);
506 
507 	bo->madv = VC4_MADV_WILLNEED;
508 
509 	ret = drm_gem_handle_create(file_priv, &bo->base.base, &args->handle);
510 	drm_gem_object_put(&bo->base.base);
511 
512 	return ret;
513 }
514 
515 static void vc4_bo_cache_free_old(struct drm_device *dev)
516 {
517 	struct vc4_dev *vc4 = to_vc4_dev(dev);
518 	unsigned long expire_time = jiffies - msecs_to_jiffies(1000);
519 
520 	lockdep_assert_held(&vc4->bo_lock);
521 
522 	while (!list_empty(&vc4->bo_cache.time_list)) {
523 		struct vc4_bo *bo = list_last_entry(&vc4->bo_cache.time_list,
524 						    struct vc4_bo, unref_head);
525 		if (time_before(expire_time, bo->free_time)) {
526 			mod_timer(&vc4->bo_cache.time_timer,
527 				  round_jiffies_up(jiffies +
528 						   msecs_to_jiffies(1000)));
529 			return;
530 		}
531 
532 		vc4_bo_remove_from_cache(bo);
533 		vc4_bo_destroy(bo);
534 	}
535 }
536 
537 /* Called on the last userspace/kernel unreference of the BO.  Returns
538  * it to the BO cache if possible, otherwise frees it.
539  */
540 static void vc4_free_object(struct drm_gem_object *gem_bo)
541 {
542 	struct drm_device *dev = gem_bo->dev;
543 	struct vc4_dev *vc4 = to_vc4_dev(dev);
544 	struct vc4_bo *bo = to_vc4_bo(gem_bo);
545 	struct list_head *cache_list;
546 
547 	/* Remove the BO from the purgeable list. */
548 	mutex_lock(&bo->madv_lock);
549 	if (bo->madv == VC4_MADV_DONTNEED && !refcount_read(&bo->usecnt))
550 		vc4_bo_remove_from_purgeable_pool(bo);
551 	mutex_unlock(&bo->madv_lock);
552 
553 	mutex_lock(&vc4->bo_lock);
554 	/* If the object references someone else's memory, we can't cache it.
555 	 */
556 	if (gem_bo->import_attach) {
557 		vc4_bo_destroy(bo);
558 		goto out;
559 	}
560 
561 	/* Don't cache if it was publicly named. */
562 	if (gem_bo->name) {
563 		vc4_bo_destroy(bo);
564 		goto out;
565 	}
566 
567 	/* If this object was partially constructed but CMA allocation
568 	 * had failed, just free it. Can also happen when the BO has been
569 	 * purged.
570 	 */
571 	if (!bo->base.vaddr) {
572 		vc4_bo_destroy(bo);
573 		goto out;
574 	}
575 
576 	cache_list = vc4_get_cache_list_for_size(dev, gem_bo->size);
577 	if (!cache_list) {
578 		vc4_bo_destroy(bo);
579 		goto out;
580 	}
581 
582 	if (bo->validated_shader) {
583 		kfree(bo->validated_shader->uniform_addr_offsets);
584 		kfree(bo->validated_shader->texture_samples);
585 		kfree(bo->validated_shader);
586 		bo->validated_shader = NULL;
587 	}
588 
589 	/* Reset madv and usecnt before adding the BO to the cache. */
590 	bo->madv = __VC4_MADV_NOTSUPP;
591 	refcount_set(&bo->usecnt, 0);
592 
593 	bo->t_format = false;
594 	bo->free_time = jiffies;
595 	list_add(&bo->size_head, cache_list);
596 	list_add(&bo->unref_head, &vc4->bo_cache.time_list);
597 
598 	vc4_bo_set_label(&bo->base.base, VC4_BO_TYPE_KERNEL_CACHE);
599 
600 	vc4_bo_cache_free_old(dev);
601 
602 out:
603 	mutex_unlock(&vc4->bo_lock);
604 }
605 
606 static void vc4_bo_cache_time_work(struct work_struct *work)
607 {
608 	struct vc4_dev *vc4 =
609 		container_of(work, struct vc4_dev, bo_cache.time_work);
610 	struct drm_device *dev = &vc4->base;
611 
612 	mutex_lock(&vc4->bo_lock);
613 	vc4_bo_cache_free_old(dev);
614 	mutex_unlock(&vc4->bo_lock);
615 }
616 
617 int vc4_bo_inc_usecnt(struct vc4_bo *bo)
618 {
619 	struct vc4_dev *vc4 = to_vc4_dev(bo->base.base.dev);
620 	int ret;
621 
622 	if (WARN_ON_ONCE(vc4->is_vc5))
623 		return -ENODEV;
624 
625 	/* Fast path: if the BO is already retained by someone, no need to
626 	 * check the madv status.
627 	 */
628 	if (refcount_inc_not_zero(&bo->usecnt))
629 		return 0;
630 
631 	mutex_lock(&bo->madv_lock);
632 	switch (bo->madv) {
633 	case VC4_MADV_WILLNEED:
634 		if (!refcount_inc_not_zero(&bo->usecnt))
635 			refcount_set(&bo->usecnt, 1);
636 		ret = 0;
637 		break;
638 	case VC4_MADV_DONTNEED:
639 		/* We shouldn't use a BO marked as purgeable if at least
640 		 * someone else retained its content by incrementing usecnt.
641 		 * Luckily the BO hasn't been purged yet, but something wrong
642 		 * is happening here. Just throw an error instead of
643 		 * authorizing this use case.
644 		 */
645 	case __VC4_MADV_PURGED:
646 		/* We can't use a purged BO. */
647 	default:
648 		/* Invalid madv value. */
649 		ret = -EINVAL;
650 		break;
651 	}
652 	mutex_unlock(&bo->madv_lock);
653 
654 	return ret;
655 }
656 
657 void vc4_bo_dec_usecnt(struct vc4_bo *bo)
658 {
659 	struct vc4_dev *vc4 = to_vc4_dev(bo->base.base.dev);
660 
661 	if (WARN_ON_ONCE(vc4->is_vc5))
662 		return;
663 
664 	/* Fast path: if the BO is still retained by someone, no need to test
665 	 * the madv value.
666 	 */
667 	if (refcount_dec_not_one(&bo->usecnt))
668 		return;
669 
670 	mutex_lock(&bo->madv_lock);
671 	if (refcount_dec_and_test(&bo->usecnt) &&
672 	    bo->madv == VC4_MADV_DONTNEED)
673 		vc4_bo_add_to_purgeable_pool(bo);
674 	mutex_unlock(&bo->madv_lock);
675 }
676 
677 static void vc4_bo_cache_time_timer(struct timer_list *t)
678 {
679 	struct vc4_dev *vc4 = from_timer(vc4, t, bo_cache.time_timer);
680 
681 	schedule_work(&vc4->bo_cache.time_work);
682 }
683 
684 static struct dma_buf *vc4_prime_export(struct drm_gem_object *obj, int flags)
685 {
686 	struct vc4_bo *bo = to_vc4_bo(obj);
687 	struct dma_buf *dmabuf;
688 	int ret;
689 
690 	if (bo->validated_shader) {
691 		DRM_DEBUG("Attempting to export shader BO\n");
692 		return ERR_PTR(-EINVAL);
693 	}
694 
695 	/* Note: as soon as the BO is exported it becomes unpurgeable, because
696 	 * noone ever decrements the usecnt even if the reference held by the
697 	 * exported BO is released. This shouldn't be a problem since we don't
698 	 * expect exported BOs to be marked as purgeable.
699 	 */
700 	ret = vc4_bo_inc_usecnt(bo);
701 	if (ret) {
702 		DRM_ERROR("Failed to increment BO usecnt\n");
703 		return ERR_PTR(ret);
704 	}
705 
706 	dmabuf = drm_gem_prime_export(obj, flags);
707 	if (IS_ERR(dmabuf))
708 		vc4_bo_dec_usecnt(bo);
709 
710 	return dmabuf;
711 }
712 
713 static vm_fault_t vc4_fault(struct vm_fault *vmf)
714 {
715 	struct vm_area_struct *vma = vmf->vma;
716 	struct drm_gem_object *obj = vma->vm_private_data;
717 	struct vc4_bo *bo = to_vc4_bo(obj);
718 
719 	/* The only reason we would end up here is when user-space accesses
720 	 * BO's memory after it's been purged.
721 	 */
722 	mutex_lock(&bo->madv_lock);
723 	WARN_ON(bo->madv != __VC4_MADV_PURGED);
724 	mutex_unlock(&bo->madv_lock);
725 
726 	return VM_FAULT_SIGBUS;
727 }
728 
729 static int vc4_gem_object_mmap(struct drm_gem_object *obj, struct vm_area_struct *vma)
730 {
731 	struct vc4_bo *bo = to_vc4_bo(obj);
732 
733 	if (bo->validated_shader && (vma->vm_flags & VM_WRITE)) {
734 		DRM_DEBUG("mmaping of shader BOs for writing not allowed.\n");
735 		return -EINVAL;
736 	}
737 
738 	if (bo->madv != VC4_MADV_WILLNEED) {
739 		DRM_DEBUG("mmaping of %s BO not allowed\n",
740 			  bo->madv == VC4_MADV_DONTNEED ?
741 			  "purgeable" : "purged");
742 		return -EINVAL;
743 	}
744 
745 	return drm_gem_cma_mmap(&bo->base, vma);
746 }
747 
748 static const struct vm_operations_struct vc4_vm_ops = {
749 	.fault = vc4_fault,
750 	.open = drm_gem_vm_open,
751 	.close = drm_gem_vm_close,
752 };
753 
754 static const struct drm_gem_object_funcs vc4_gem_object_funcs = {
755 	.free = vc4_free_object,
756 	.export = vc4_prime_export,
757 	.get_sg_table = drm_gem_cma_object_get_sg_table,
758 	.vmap = drm_gem_cma_object_vmap,
759 	.mmap = vc4_gem_object_mmap,
760 	.vm_ops = &vc4_vm_ops,
761 };
762 
763 static int vc4_grab_bin_bo(struct vc4_dev *vc4, struct vc4_file *vc4file)
764 {
765 	if (!vc4->v3d)
766 		return -ENODEV;
767 
768 	if (vc4file->bin_bo_used)
769 		return 0;
770 
771 	return vc4_v3d_bin_bo_get(vc4, &vc4file->bin_bo_used);
772 }
773 
774 int vc4_create_bo_ioctl(struct drm_device *dev, void *data,
775 			struct drm_file *file_priv)
776 {
777 	struct drm_vc4_create_bo *args = data;
778 	struct vc4_file *vc4file = file_priv->driver_priv;
779 	struct vc4_dev *vc4 = to_vc4_dev(dev);
780 	struct vc4_bo *bo = NULL;
781 	int ret;
782 
783 	if (WARN_ON_ONCE(vc4->is_vc5))
784 		return -ENODEV;
785 
786 	ret = vc4_grab_bin_bo(vc4, vc4file);
787 	if (ret)
788 		return ret;
789 
790 	/*
791 	 * We can't allocate from the BO cache, because the BOs don't
792 	 * get zeroed, and that might leak data between users.
793 	 */
794 	bo = vc4_bo_create(dev, args->size, false, VC4_BO_TYPE_V3D);
795 	if (IS_ERR(bo))
796 		return PTR_ERR(bo);
797 
798 	bo->madv = VC4_MADV_WILLNEED;
799 
800 	ret = drm_gem_handle_create(file_priv, &bo->base.base, &args->handle);
801 	drm_gem_object_put(&bo->base.base);
802 
803 	return ret;
804 }
805 
806 int vc4_mmap_bo_ioctl(struct drm_device *dev, void *data,
807 		      struct drm_file *file_priv)
808 {
809 	struct vc4_dev *vc4 = to_vc4_dev(dev);
810 	struct drm_vc4_mmap_bo *args = data;
811 	struct drm_gem_object *gem_obj;
812 
813 	if (WARN_ON_ONCE(vc4->is_vc5))
814 		return -ENODEV;
815 
816 	gem_obj = drm_gem_object_lookup(file_priv, args->handle);
817 	if (!gem_obj) {
818 		DRM_DEBUG("Failed to look up GEM BO %d\n", args->handle);
819 		return -EINVAL;
820 	}
821 
822 	/* The mmap offset was set up at BO allocation time. */
823 	args->offset = drm_vma_node_offset_addr(&gem_obj->vma_node);
824 
825 	drm_gem_object_put(gem_obj);
826 	return 0;
827 }
828 
829 int
830 vc4_create_shader_bo_ioctl(struct drm_device *dev, void *data,
831 			   struct drm_file *file_priv)
832 {
833 	struct drm_vc4_create_shader_bo *args = data;
834 	struct vc4_file *vc4file = file_priv->driver_priv;
835 	struct vc4_dev *vc4 = to_vc4_dev(dev);
836 	struct vc4_bo *bo = NULL;
837 	int ret;
838 
839 	if (WARN_ON_ONCE(vc4->is_vc5))
840 		return -ENODEV;
841 
842 	if (args->size == 0)
843 		return -EINVAL;
844 
845 	if (args->size % sizeof(u64) != 0)
846 		return -EINVAL;
847 
848 	if (args->flags != 0) {
849 		DRM_INFO("Unknown flags set: 0x%08x\n", args->flags);
850 		return -EINVAL;
851 	}
852 
853 	if (args->pad != 0) {
854 		DRM_INFO("Pad set: 0x%08x\n", args->pad);
855 		return -EINVAL;
856 	}
857 
858 	ret = vc4_grab_bin_bo(vc4, vc4file);
859 	if (ret)
860 		return ret;
861 
862 	bo = vc4_bo_create(dev, args->size, true, VC4_BO_TYPE_V3D_SHADER);
863 	if (IS_ERR(bo))
864 		return PTR_ERR(bo);
865 
866 	bo->madv = VC4_MADV_WILLNEED;
867 
868 	if (copy_from_user(bo->base.vaddr,
869 			     (void __user *)(uintptr_t)args->data,
870 			     args->size)) {
871 		ret = -EFAULT;
872 		goto fail;
873 	}
874 	/* Clear the rest of the memory from allocating from the BO
875 	 * cache.
876 	 */
877 	memset(bo->base.vaddr + args->size, 0,
878 	       bo->base.base.size - args->size);
879 
880 	bo->validated_shader = vc4_validate_shader(&bo->base);
881 	if (!bo->validated_shader) {
882 		ret = -EINVAL;
883 		goto fail;
884 	}
885 
886 	/* We have to create the handle after validation, to avoid
887 	 * races for users to do doing things like mmap the shader BO.
888 	 */
889 	ret = drm_gem_handle_create(file_priv, &bo->base.base, &args->handle);
890 
891 fail:
892 	drm_gem_object_put(&bo->base.base);
893 
894 	return ret;
895 }
896 
897 /**
898  * vc4_set_tiling_ioctl() - Sets the tiling modifier for a BO.
899  * @dev: DRM device
900  * @data: ioctl argument
901  * @file_priv: DRM file for this fd
902  *
903  * The tiling state of the BO decides the default modifier of an fb if
904  * no specific modifier was set by userspace, and the return value of
905  * vc4_get_tiling_ioctl() (so that userspace can treat a BO it
906  * received from dmabuf as the same tiling format as the producer
907  * used).
908  */
909 int vc4_set_tiling_ioctl(struct drm_device *dev, void *data,
910 			 struct drm_file *file_priv)
911 {
912 	struct vc4_dev *vc4 = to_vc4_dev(dev);
913 	struct drm_vc4_set_tiling *args = data;
914 	struct drm_gem_object *gem_obj;
915 	struct vc4_bo *bo;
916 	bool t_format;
917 
918 	if (WARN_ON_ONCE(vc4->is_vc5))
919 		return -ENODEV;
920 
921 	if (args->flags != 0)
922 		return -EINVAL;
923 
924 	switch (args->modifier) {
925 	case DRM_FORMAT_MOD_NONE:
926 		t_format = false;
927 		break;
928 	case DRM_FORMAT_MOD_BROADCOM_VC4_T_TILED:
929 		t_format = true;
930 		break;
931 	default:
932 		return -EINVAL;
933 	}
934 
935 	gem_obj = drm_gem_object_lookup(file_priv, args->handle);
936 	if (!gem_obj) {
937 		DRM_DEBUG("Failed to look up GEM BO %d\n", args->handle);
938 		return -ENOENT;
939 	}
940 	bo = to_vc4_bo(gem_obj);
941 	bo->t_format = t_format;
942 
943 	drm_gem_object_put(gem_obj);
944 
945 	return 0;
946 }
947 
948 /**
949  * vc4_get_tiling_ioctl() - Gets the tiling modifier for a BO.
950  * @dev: DRM device
951  * @data: ioctl argument
952  * @file_priv: DRM file for this fd
953  *
954  * Returns the tiling modifier for a BO as set by vc4_set_tiling_ioctl().
955  */
956 int vc4_get_tiling_ioctl(struct drm_device *dev, void *data,
957 			 struct drm_file *file_priv)
958 {
959 	struct vc4_dev *vc4 = to_vc4_dev(dev);
960 	struct drm_vc4_get_tiling *args = data;
961 	struct drm_gem_object *gem_obj;
962 	struct vc4_bo *bo;
963 
964 	if (WARN_ON_ONCE(vc4->is_vc5))
965 		return -ENODEV;
966 
967 	if (args->flags != 0 || args->modifier != 0)
968 		return -EINVAL;
969 
970 	gem_obj = drm_gem_object_lookup(file_priv, args->handle);
971 	if (!gem_obj) {
972 		DRM_DEBUG("Failed to look up GEM BO %d\n", args->handle);
973 		return -ENOENT;
974 	}
975 	bo = to_vc4_bo(gem_obj);
976 
977 	if (bo->t_format)
978 		args->modifier = DRM_FORMAT_MOD_BROADCOM_VC4_T_TILED;
979 	else
980 		args->modifier = DRM_FORMAT_MOD_NONE;
981 
982 	drm_gem_object_put(gem_obj);
983 
984 	return 0;
985 }
986 
987 static void vc4_bo_cache_destroy(struct drm_device *dev, void *unused);
988 int vc4_bo_cache_init(struct drm_device *dev)
989 {
990 	struct vc4_dev *vc4 = to_vc4_dev(dev);
991 	int i;
992 
993 	if (WARN_ON_ONCE(vc4->is_vc5))
994 		return -ENODEV;
995 
996 	/* Create the initial set of BO labels that the kernel will
997 	 * use.  This lets us avoid a bunch of string reallocation in
998 	 * the kernel's draw and BO allocation paths.
999 	 */
1000 	vc4->bo_labels = kcalloc(VC4_BO_TYPE_COUNT, sizeof(*vc4->bo_labels),
1001 				 GFP_KERNEL);
1002 	if (!vc4->bo_labels)
1003 		return -ENOMEM;
1004 	vc4->num_labels = VC4_BO_TYPE_COUNT;
1005 
1006 	BUILD_BUG_ON(ARRAY_SIZE(bo_type_names) != VC4_BO_TYPE_COUNT);
1007 	for (i = 0; i < VC4_BO_TYPE_COUNT; i++)
1008 		vc4->bo_labels[i].name = bo_type_names[i];
1009 
1010 	mutex_init(&vc4->bo_lock);
1011 
1012 	vc4_debugfs_add_file(dev, "bo_stats", vc4_bo_stats_debugfs, NULL);
1013 
1014 	INIT_LIST_HEAD(&vc4->bo_cache.time_list);
1015 
1016 	INIT_WORK(&vc4->bo_cache.time_work, vc4_bo_cache_time_work);
1017 	timer_setup(&vc4->bo_cache.time_timer, vc4_bo_cache_time_timer, 0);
1018 
1019 	return drmm_add_action_or_reset(dev, vc4_bo_cache_destroy, NULL);
1020 }
1021 
1022 static void vc4_bo_cache_destroy(struct drm_device *dev, void *unused)
1023 {
1024 	struct vc4_dev *vc4 = to_vc4_dev(dev);
1025 	int i;
1026 
1027 	del_timer(&vc4->bo_cache.time_timer);
1028 	cancel_work_sync(&vc4->bo_cache.time_work);
1029 
1030 	vc4_bo_cache_purge(dev);
1031 
1032 	for (i = 0; i < vc4->num_labels; i++) {
1033 		if (vc4->bo_labels[i].num_allocated) {
1034 			DRM_ERROR("Destroying BO cache with %d %s "
1035 				  "BOs still allocated\n",
1036 				  vc4->bo_labels[i].num_allocated,
1037 				  vc4->bo_labels[i].name);
1038 		}
1039 
1040 		if (is_user_label(i))
1041 			kfree(vc4->bo_labels[i].name);
1042 	}
1043 	kfree(vc4->bo_labels);
1044 }
1045 
1046 int vc4_label_bo_ioctl(struct drm_device *dev, void *data,
1047 		       struct drm_file *file_priv)
1048 {
1049 	struct vc4_dev *vc4 = to_vc4_dev(dev);
1050 	struct drm_vc4_label_bo *args = data;
1051 	char *name;
1052 	struct drm_gem_object *gem_obj;
1053 	int ret = 0, label;
1054 
1055 	if (WARN_ON_ONCE(vc4->is_vc5))
1056 		return -ENODEV;
1057 
1058 	if (!args->len)
1059 		return -EINVAL;
1060 
1061 	name = strndup_user(u64_to_user_ptr(args->name), args->len + 1);
1062 	if (IS_ERR(name))
1063 		return PTR_ERR(name);
1064 
1065 	gem_obj = drm_gem_object_lookup(file_priv, args->handle);
1066 	if (!gem_obj) {
1067 		DRM_ERROR("Failed to look up GEM BO %d\n", args->handle);
1068 		kfree(name);
1069 		return -ENOENT;
1070 	}
1071 
1072 	mutex_lock(&vc4->bo_lock);
1073 	label = vc4_get_user_label(vc4, name);
1074 	if (label != -1)
1075 		vc4_bo_set_label(gem_obj, label);
1076 	else
1077 		ret = -ENOMEM;
1078 	mutex_unlock(&vc4->bo_lock);
1079 
1080 	drm_gem_object_put(gem_obj);
1081 
1082 	return ret;
1083 }
1084