xref: /linux/drivers/gpu/drm/vc4/vc4_bo.c (revision 26fbb4c8c7c3ee9a4c3b4de555a8587b5a19154e)
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_object(obj);
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 	mutex_lock(&vc4->purgeable.lock);
252 	list_add_tail(&bo->size_head, &vc4->purgeable.list);
253 	vc4->purgeable.num++;
254 	vc4->purgeable.size += bo->base.base.size;
255 	mutex_unlock(&vc4->purgeable.lock);
256 }
257 
258 static void vc4_bo_remove_from_purgeable_pool_locked(struct vc4_bo *bo)
259 {
260 	struct vc4_dev *vc4 = to_vc4_dev(bo->base.base.dev);
261 
262 	/* list_del_init() is used here because the caller might release
263 	 * the purgeable lock in order to acquire the madv one and update the
264 	 * madv status.
265 	 * During this short period of time a user might decide to mark
266 	 * the BO as unpurgeable, and if bo->madv is set to
267 	 * VC4_MADV_DONTNEED it will try to remove the BO from the
268 	 * purgeable list which will fail if the ->next/prev fields
269 	 * are set to LIST_POISON1/LIST_POISON2 (which is what
270 	 * list_del() does).
271 	 * Re-initializing the list element guarantees that list_del()
272 	 * will work correctly even if it's a NOP.
273 	 */
274 	list_del_init(&bo->size_head);
275 	vc4->purgeable.num--;
276 	vc4->purgeable.size -= bo->base.base.size;
277 }
278 
279 void vc4_bo_remove_from_purgeable_pool(struct vc4_bo *bo)
280 {
281 	struct vc4_dev *vc4 = to_vc4_dev(bo->base.base.dev);
282 
283 	mutex_lock(&vc4->purgeable.lock);
284 	vc4_bo_remove_from_purgeable_pool_locked(bo);
285 	mutex_unlock(&vc4->purgeable.lock);
286 }
287 
288 static void vc4_bo_purge(struct drm_gem_object *obj)
289 {
290 	struct vc4_bo *bo = to_vc4_bo(obj);
291 	struct drm_device *dev = obj->dev;
292 
293 	WARN_ON(!mutex_is_locked(&bo->madv_lock));
294 	WARN_ON(bo->madv != VC4_MADV_DONTNEED);
295 
296 	drm_vma_node_unmap(&obj->vma_node, dev->anon_inode->i_mapping);
297 
298 	dma_free_wc(dev->dev, obj->size, bo->base.vaddr, bo->base.paddr);
299 	bo->base.vaddr = NULL;
300 	bo->madv = __VC4_MADV_PURGED;
301 }
302 
303 static void vc4_bo_userspace_cache_purge(struct drm_device *dev)
304 {
305 	struct vc4_dev *vc4 = to_vc4_dev(dev);
306 
307 	mutex_lock(&vc4->purgeable.lock);
308 	while (!list_empty(&vc4->purgeable.list)) {
309 		struct vc4_bo *bo = list_first_entry(&vc4->purgeable.list,
310 						     struct vc4_bo, size_head);
311 		struct drm_gem_object *obj = &bo->base.base;
312 		size_t purged_size = 0;
313 
314 		vc4_bo_remove_from_purgeable_pool_locked(bo);
315 
316 		/* Release the purgeable lock while we're purging the BO so
317 		 * that other people can continue inserting things in the
318 		 * purgeable pool without having to wait for all BOs to be
319 		 * purged.
320 		 */
321 		mutex_unlock(&vc4->purgeable.lock);
322 		mutex_lock(&bo->madv_lock);
323 
324 		/* Since we released the purgeable pool lock before acquiring
325 		 * the BO madv one, the user may have marked the BO as WILLNEED
326 		 * and re-used it in the meantime.
327 		 * Before purging the BO we need to make sure
328 		 * - it is still marked as DONTNEED
329 		 * - it has not been re-inserted in the purgeable list
330 		 * - it is not used by HW blocks
331 		 * If one of these conditions is not met, just skip the entry.
332 		 */
333 		if (bo->madv == VC4_MADV_DONTNEED &&
334 		    list_empty(&bo->size_head) &&
335 		    !refcount_read(&bo->usecnt)) {
336 			purged_size = bo->base.base.size;
337 			vc4_bo_purge(obj);
338 		}
339 		mutex_unlock(&bo->madv_lock);
340 		mutex_lock(&vc4->purgeable.lock);
341 
342 		if (purged_size) {
343 			vc4->purgeable.purged_size += purged_size;
344 			vc4->purgeable.purged_num++;
345 		}
346 	}
347 	mutex_unlock(&vc4->purgeable.lock);
348 }
349 
350 static struct vc4_bo *vc4_bo_get_from_cache(struct drm_device *dev,
351 					    uint32_t size,
352 					    enum vc4_kernel_bo_type type)
353 {
354 	struct vc4_dev *vc4 = to_vc4_dev(dev);
355 	uint32_t page_index = bo_page_index(size);
356 	struct vc4_bo *bo = NULL;
357 
358 	size = roundup(size, PAGE_SIZE);
359 
360 	mutex_lock(&vc4->bo_lock);
361 	if (page_index >= vc4->bo_cache.size_list_size)
362 		goto out;
363 
364 	if (list_empty(&vc4->bo_cache.size_list[page_index]))
365 		goto out;
366 
367 	bo = list_first_entry(&vc4->bo_cache.size_list[page_index],
368 			      struct vc4_bo, size_head);
369 	vc4_bo_remove_from_cache(bo);
370 	kref_init(&bo->base.base.refcount);
371 
372 out:
373 	if (bo)
374 		vc4_bo_set_label(&bo->base.base, type);
375 	mutex_unlock(&vc4->bo_lock);
376 	return bo;
377 }
378 
379 /**
380  * vc4_create_object - Implementation of driver->gem_create_object.
381  * @dev: DRM device
382  * @size: Size in bytes of the memory the object will reference
383  *
384  * This lets the CMA helpers allocate object structs for us, and keep
385  * our BO stats correct.
386  */
387 struct drm_gem_object *vc4_create_object(struct drm_device *dev, size_t size)
388 {
389 	struct vc4_dev *vc4 = to_vc4_dev(dev);
390 	struct vc4_bo *bo;
391 
392 	bo = kzalloc(sizeof(*bo), GFP_KERNEL);
393 	if (!bo)
394 		return ERR_PTR(-ENOMEM);
395 
396 	bo->madv = VC4_MADV_WILLNEED;
397 	refcount_set(&bo->usecnt, 0);
398 	mutex_init(&bo->madv_lock);
399 	mutex_lock(&vc4->bo_lock);
400 	bo->label = VC4_BO_TYPE_KERNEL;
401 	vc4->bo_labels[VC4_BO_TYPE_KERNEL].num_allocated++;
402 	vc4->bo_labels[VC4_BO_TYPE_KERNEL].size_allocated += size;
403 	mutex_unlock(&vc4->bo_lock);
404 
405 	bo->base.base.funcs = &vc4_gem_object_funcs;
406 
407 	return &bo->base.base;
408 }
409 
410 struct vc4_bo *vc4_bo_create(struct drm_device *dev, size_t unaligned_size,
411 			     bool allow_unzeroed, enum vc4_kernel_bo_type type)
412 {
413 	size_t size = roundup(unaligned_size, PAGE_SIZE);
414 	struct vc4_dev *vc4 = to_vc4_dev(dev);
415 	struct drm_gem_cma_object *cma_obj;
416 	struct vc4_bo *bo;
417 
418 	if (size == 0)
419 		return ERR_PTR(-EINVAL);
420 
421 	/* First, try to get a vc4_bo from the kernel BO cache. */
422 	bo = vc4_bo_get_from_cache(dev, size, type);
423 	if (bo) {
424 		if (!allow_unzeroed)
425 			memset(bo->base.vaddr, 0, bo->base.base.size);
426 		return bo;
427 	}
428 
429 	cma_obj = drm_gem_cma_create(dev, size);
430 	if (IS_ERR(cma_obj)) {
431 		/*
432 		 * If we've run out of CMA memory, kill the cache of
433 		 * CMA allocations we've got laying around and try again.
434 		 */
435 		vc4_bo_cache_purge(dev);
436 		cma_obj = drm_gem_cma_create(dev, size);
437 	}
438 
439 	if (IS_ERR(cma_obj)) {
440 		/*
441 		 * Still not enough CMA memory, purge the userspace BO
442 		 * cache and retry.
443 		 * This is sub-optimal since we purge the whole userspace
444 		 * BO cache which forces user that want to re-use the BO to
445 		 * restore its initial content.
446 		 * Ideally, we should purge entries one by one and retry
447 		 * after each to see if CMA allocation succeeds. Or even
448 		 * better, try to find an entry with at least the same
449 		 * size.
450 		 */
451 		vc4_bo_userspace_cache_purge(dev);
452 		cma_obj = drm_gem_cma_create(dev, size);
453 	}
454 
455 	if (IS_ERR(cma_obj)) {
456 		struct drm_printer p = drm_info_printer(vc4->base.dev);
457 		DRM_ERROR("Failed to allocate from CMA:\n");
458 		vc4_bo_stats_print(&p, vc4);
459 		return ERR_PTR(-ENOMEM);
460 	}
461 	bo = to_vc4_bo(&cma_obj->base);
462 
463 	/* By default, BOs do not support the MADV ioctl. This will be enabled
464 	 * only on BOs that are exposed to userspace (V3D, V3D_SHADER and DUMB
465 	 * BOs).
466 	 */
467 	bo->madv = __VC4_MADV_NOTSUPP;
468 
469 	mutex_lock(&vc4->bo_lock);
470 	vc4_bo_set_label(&cma_obj->base, type);
471 	mutex_unlock(&vc4->bo_lock);
472 
473 	return bo;
474 }
475 
476 int vc4_dumb_create(struct drm_file *file_priv,
477 		    struct drm_device *dev,
478 		    struct drm_mode_create_dumb *args)
479 {
480 	int min_pitch = DIV_ROUND_UP(args->width * args->bpp, 8);
481 	struct vc4_bo *bo = NULL;
482 	int ret;
483 
484 	if (args->pitch < min_pitch)
485 		args->pitch = min_pitch;
486 
487 	if (args->size < args->pitch * args->height)
488 		args->size = args->pitch * args->height;
489 
490 	bo = vc4_bo_create(dev, args->size, false, VC4_BO_TYPE_DUMB);
491 	if (IS_ERR(bo))
492 		return PTR_ERR(bo);
493 
494 	bo->madv = VC4_MADV_WILLNEED;
495 
496 	ret = drm_gem_handle_create(file_priv, &bo->base.base, &args->handle);
497 	drm_gem_object_put(&bo->base.base);
498 
499 	return ret;
500 }
501 
502 static void vc4_bo_cache_free_old(struct drm_device *dev)
503 {
504 	struct vc4_dev *vc4 = to_vc4_dev(dev);
505 	unsigned long expire_time = jiffies - msecs_to_jiffies(1000);
506 
507 	lockdep_assert_held(&vc4->bo_lock);
508 
509 	while (!list_empty(&vc4->bo_cache.time_list)) {
510 		struct vc4_bo *bo = list_last_entry(&vc4->bo_cache.time_list,
511 						    struct vc4_bo, unref_head);
512 		if (time_before(expire_time, bo->free_time)) {
513 			mod_timer(&vc4->bo_cache.time_timer,
514 				  round_jiffies_up(jiffies +
515 						   msecs_to_jiffies(1000)));
516 			return;
517 		}
518 
519 		vc4_bo_remove_from_cache(bo);
520 		vc4_bo_destroy(bo);
521 	}
522 }
523 
524 /* Called on the last userspace/kernel unreference of the BO.  Returns
525  * it to the BO cache if possible, otherwise frees it.
526  */
527 static void vc4_free_object(struct drm_gem_object *gem_bo)
528 {
529 	struct drm_device *dev = gem_bo->dev;
530 	struct vc4_dev *vc4 = to_vc4_dev(dev);
531 	struct vc4_bo *bo = to_vc4_bo(gem_bo);
532 	struct list_head *cache_list;
533 
534 	/* Remove the BO from the purgeable list. */
535 	mutex_lock(&bo->madv_lock);
536 	if (bo->madv == VC4_MADV_DONTNEED && !refcount_read(&bo->usecnt))
537 		vc4_bo_remove_from_purgeable_pool(bo);
538 	mutex_unlock(&bo->madv_lock);
539 
540 	mutex_lock(&vc4->bo_lock);
541 	/* If the object references someone else's memory, we can't cache it.
542 	 */
543 	if (gem_bo->import_attach) {
544 		vc4_bo_destroy(bo);
545 		goto out;
546 	}
547 
548 	/* Don't cache if it was publicly named. */
549 	if (gem_bo->name) {
550 		vc4_bo_destroy(bo);
551 		goto out;
552 	}
553 
554 	/* If this object was partially constructed but CMA allocation
555 	 * had failed, just free it. Can also happen when the BO has been
556 	 * purged.
557 	 */
558 	if (!bo->base.vaddr) {
559 		vc4_bo_destroy(bo);
560 		goto out;
561 	}
562 
563 	cache_list = vc4_get_cache_list_for_size(dev, gem_bo->size);
564 	if (!cache_list) {
565 		vc4_bo_destroy(bo);
566 		goto out;
567 	}
568 
569 	if (bo->validated_shader) {
570 		kfree(bo->validated_shader->uniform_addr_offsets);
571 		kfree(bo->validated_shader->texture_samples);
572 		kfree(bo->validated_shader);
573 		bo->validated_shader = NULL;
574 	}
575 
576 	/* Reset madv and usecnt before adding the BO to the cache. */
577 	bo->madv = __VC4_MADV_NOTSUPP;
578 	refcount_set(&bo->usecnt, 0);
579 
580 	bo->t_format = false;
581 	bo->free_time = jiffies;
582 	list_add(&bo->size_head, cache_list);
583 	list_add(&bo->unref_head, &vc4->bo_cache.time_list);
584 
585 	vc4_bo_set_label(&bo->base.base, VC4_BO_TYPE_KERNEL_CACHE);
586 
587 	vc4_bo_cache_free_old(dev);
588 
589 out:
590 	mutex_unlock(&vc4->bo_lock);
591 }
592 
593 static void vc4_bo_cache_time_work(struct work_struct *work)
594 {
595 	struct vc4_dev *vc4 =
596 		container_of(work, struct vc4_dev, bo_cache.time_work);
597 	struct drm_device *dev = &vc4->base;
598 
599 	mutex_lock(&vc4->bo_lock);
600 	vc4_bo_cache_free_old(dev);
601 	mutex_unlock(&vc4->bo_lock);
602 }
603 
604 int vc4_bo_inc_usecnt(struct vc4_bo *bo)
605 {
606 	int ret;
607 
608 	/* Fast path: if the BO is already retained by someone, no need to
609 	 * check the madv status.
610 	 */
611 	if (refcount_inc_not_zero(&bo->usecnt))
612 		return 0;
613 
614 	mutex_lock(&bo->madv_lock);
615 	switch (bo->madv) {
616 	case VC4_MADV_WILLNEED:
617 		if (!refcount_inc_not_zero(&bo->usecnt))
618 			refcount_set(&bo->usecnt, 1);
619 		ret = 0;
620 		break;
621 	case VC4_MADV_DONTNEED:
622 		/* We shouldn't use a BO marked as purgeable if at least
623 		 * someone else retained its content by incrementing usecnt.
624 		 * Luckily the BO hasn't been purged yet, but something wrong
625 		 * is happening here. Just throw an error instead of
626 		 * authorizing this use case.
627 		 */
628 	case __VC4_MADV_PURGED:
629 		/* We can't use a purged BO. */
630 	default:
631 		/* Invalid madv value. */
632 		ret = -EINVAL;
633 		break;
634 	}
635 	mutex_unlock(&bo->madv_lock);
636 
637 	return ret;
638 }
639 
640 void vc4_bo_dec_usecnt(struct vc4_bo *bo)
641 {
642 	/* Fast path: if the BO is still retained by someone, no need to test
643 	 * the madv value.
644 	 */
645 	if (refcount_dec_not_one(&bo->usecnt))
646 		return;
647 
648 	mutex_lock(&bo->madv_lock);
649 	if (refcount_dec_and_test(&bo->usecnt) &&
650 	    bo->madv == VC4_MADV_DONTNEED)
651 		vc4_bo_add_to_purgeable_pool(bo);
652 	mutex_unlock(&bo->madv_lock);
653 }
654 
655 static void vc4_bo_cache_time_timer(struct timer_list *t)
656 {
657 	struct vc4_dev *vc4 = from_timer(vc4, t, bo_cache.time_timer);
658 
659 	schedule_work(&vc4->bo_cache.time_work);
660 }
661 
662 static struct dma_buf *vc4_prime_export(struct drm_gem_object *obj, int flags)
663 {
664 	struct vc4_bo *bo = to_vc4_bo(obj);
665 	struct dma_buf *dmabuf;
666 	int ret;
667 
668 	if (bo->validated_shader) {
669 		DRM_DEBUG("Attempting to export shader BO\n");
670 		return ERR_PTR(-EINVAL);
671 	}
672 
673 	/* Note: as soon as the BO is exported it becomes unpurgeable, because
674 	 * noone ever decrements the usecnt even if the reference held by the
675 	 * exported BO is released. This shouldn't be a problem since we don't
676 	 * expect exported BOs to be marked as purgeable.
677 	 */
678 	ret = vc4_bo_inc_usecnt(bo);
679 	if (ret) {
680 		DRM_ERROR("Failed to increment BO usecnt\n");
681 		return ERR_PTR(ret);
682 	}
683 
684 	dmabuf = drm_gem_prime_export(obj, flags);
685 	if (IS_ERR(dmabuf))
686 		vc4_bo_dec_usecnt(bo);
687 
688 	return dmabuf;
689 }
690 
691 static vm_fault_t vc4_fault(struct vm_fault *vmf)
692 {
693 	struct vm_area_struct *vma = vmf->vma;
694 	struct drm_gem_object *obj = vma->vm_private_data;
695 	struct vc4_bo *bo = to_vc4_bo(obj);
696 
697 	/* The only reason we would end up here is when user-space accesses
698 	 * BO's memory after it's been purged.
699 	 */
700 	mutex_lock(&bo->madv_lock);
701 	WARN_ON(bo->madv != __VC4_MADV_PURGED);
702 	mutex_unlock(&bo->madv_lock);
703 
704 	return VM_FAULT_SIGBUS;
705 }
706 
707 static int vc4_gem_object_mmap(struct drm_gem_object *obj, struct vm_area_struct *vma)
708 {
709 	struct vc4_bo *bo = to_vc4_bo(obj);
710 
711 	if (bo->validated_shader && (vma->vm_flags & VM_WRITE)) {
712 		DRM_DEBUG("mmaping of shader BOs for writing not allowed.\n");
713 		return -EINVAL;
714 	}
715 
716 	if (bo->madv != VC4_MADV_WILLNEED) {
717 		DRM_DEBUG("mmaping of %s BO not allowed\n",
718 			  bo->madv == VC4_MADV_DONTNEED ?
719 			  "purgeable" : "purged");
720 		return -EINVAL;
721 	}
722 
723 	return drm_gem_cma_mmap(obj, vma);
724 }
725 
726 static const struct vm_operations_struct vc4_vm_ops = {
727 	.fault = vc4_fault,
728 	.open = drm_gem_vm_open,
729 	.close = drm_gem_vm_close,
730 };
731 
732 static const struct drm_gem_object_funcs vc4_gem_object_funcs = {
733 	.free = vc4_free_object,
734 	.export = vc4_prime_export,
735 	.get_sg_table = drm_gem_cma_get_sg_table,
736 	.vmap = drm_gem_cma_vmap,
737 	.mmap = vc4_gem_object_mmap,
738 	.vm_ops = &vc4_vm_ops,
739 };
740 
741 static int vc4_grab_bin_bo(struct vc4_dev *vc4, struct vc4_file *vc4file)
742 {
743 	int ret;
744 
745 	if (!vc4->v3d)
746 		return -ENODEV;
747 
748 	if (vc4file->bin_bo_used)
749 		return 0;
750 
751 	ret = vc4_v3d_bin_bo_get(vc4, &vc4file->bin_bo_used);
752 	if (ret)
753 		return ret;
754 
755 	return 0;
756 }
757 
758 int vc4_create_bo_ioctl(struct drm_device *dev, void *data,
759 			struct drm_file *file_priv)
760 {
761 	struct drm_vc4_create_bo *args = data;
762 	struct vc4_file *vc4file = file_priv->driver_priv;
763 	struct vc4_dev *vc4 = to_vc4_dev(dev);
764 	struct vc4_bo *bo = NULL;
765 	int ret;
766 
767 	ret = vc4_grab_bin_bo(vc4, vc4file);
768 	if (ret)
769 		return ret;
770 
771 	/*
772 	 * We can't allocate from the BO cache, because the BOs don't
773 	 * get zeroed, and that might leak data between users.
774 	 */
775 	bo = vc4_bo_create(dev, args->size, false, VC4_BO_TYPE_V3D);
776 	if (IS_ERR(bo))
777 		return PTR_ERR(bo);
778 
779 	bo->madv = VC4_MADV_WILLNEED;
780 
781 	ret = drm_gem_handle_create(file_priv, &bo->base.base, &args->handle);
782 	drm_gem_object_put(&bo->base.base);
783 
784 	return ret;
785 }
786 
787 int vc4_mmap_bo_ioctl(struct drm_device *dev, void *data,
788 		      struct drm_file *file_priv)
789 {
790 	struct drm_vc4_mmap_bo *args = data;
791 	struct drm_gem_object *gem_obj;
792 
793 	gem_obj = drm_gem_object_lookup(file_priv, args->handle);
794 	if (!gem_obj) {
795 		DRM_DEBUG("Failed to look up GEM BO %d\n", args->handle);
796 		return -EINVAL;
797 	}
798 
799 	/* The mmap offset was set up at BO allocation time. */
800 	args->offset = drm_vma_node_offset_addr(&gem_obj->vma_node);
801 
802 	drm_gem_object_put(gem_obj);
803 	return 0;
804 }
805 
806 int
807 vc4_create_shader_bo_ioctl(struct drm_device *dev, void *data,
808 			   struct drm_file *file_priv)
809 {
810 	struct drm_vc4_create_shader_bo *args = data;
811 	struct vc4_file *vc4file = file_priv->driver_priv;
812 	struct vc4_dev *vc4 = to_vc4_dev(dev);
813 	struct vc4_bo *bo = NULL;
814 	int ret;
815 
816 	if (args->size == 0)
817 		return -EINVAL;
818 
819 	if (args->size % sizeof(u64) != 0)
820 		return -EINVAL;
821 
822 	if (args->flags != 0) {
823 		DRM_INFO("Unknown flags set: 0x%08x\n", args->flags);
824 		return -EINVAL;
825 	}
826 
827 	if (args->pad != 0) {
828 		DRM_INFO("Pad set: 0x%08x\n", args->pad);
829 		return -EINVAL;
830 	}
831 
832 	ret = vc4_grab_bin_bo(vc4, vc4file);
833 	if (ret)
834 		return ret;
835 
836 	bo = vc4_bo_create(dev, args->size, true, VC4_BO_TYPE_V3D_SHADER);
837 	if (IS_ERR(bo))
838 		return PTR_ERR(bo);
839 
840 	bo->madv = VC4_MADV_WILLNEED;
841 
842 	if (copy_from_user(bo->base.vaddr,
843 			     (void __user *)(uintptr_t)args->data,
844 			     args->size)) {
845 		ret = -EFAULT;
846 		goto fail;
847 	}
848 	/* Clear the rest of the memory from allocating from the BO
849 	 * cache.
850 	 */
851 	memset(bo->base.vaddr + args->size, 0,
852 	       bo->base.base.size - args->size);
853 
854 	bo->validated_shader = vc4_validate_shader(&bo->base);
855 	if (!bo->validated_shader) {
856 		ret = -EINVAL;
857 		goto fail;
858 	}
859 
860 	/* We have to create the handle after validation, to avoid
861 	 * races for users to do doing things like mmap the shader BO.
862 	 */
863 	ret = drm_gem_handle_create(file_priv, &bo->base.base, &args->handle);
864 
865 fail:
866 	drm_gem_object_put(&bo->base.base);
867 
868 	return ret;
869 }
870 
871 /**
872  * vc4_set_tiling_ioctl() - Sets the tiling modifier for a BO.
873  * @dev: DRM device
874  * @data: ioctl argument
875  * @file_priv: DRM file for this fd
876  *
877  * The tiling state of the BO decides the default modifier of an fb if
878  * no specific modifier was set by userspace, and the return value of
879  * vc4_get_tiling_ioctl() (so that userspace can treat a BO it
880  * received from dmabuf as the same tiling format as the producer
881  * used).
882  */
883 int vc4_set_tiling_ioctl(struct drm_device *dev, void *data,
884 			 struct drm_file *file_priv)
885 {
886 	struct drm_vc4_set_tiling *args = data;
887 	struct drm_gem_object *gem_obj;
888 	struct vc4_bo *bo;
889 	bool t_format;
890 
891 	if (args->flags != 0)
892 		return -EINVAL;
893 
894 	switch (args->modifier) {
895 	case DRM_FORMAT_MOD_NONE:
896 		t_format = false;
897 		break;
898 	case DRM_FORMAT_MOD_BROADCOM_VC4_T_TILED:
899 		t_format = true;
900 		break;
901 	default:
902 		return -EINVAL;
903 	}
904 
905 	gem_obj = drm_gem_object_lookup(file_priv, args->handle);
906 	if (!gem_obj) {
907 		DRM_DEBUG("Failed to look up GEM BO %d\n", args->handle);
908 		return -ENOENT;
909 	}
910 	bo = to_vc4_bo(gem_obj);
911 	bo->t_format = t_format;
912 
913 	drm_gem_object_put(gem_obj);
914 
915 	return 0;
916 }
917 
918 /**
919  * vc4_get_tiling_ioctl() - Gets the tiling modifier for a BO.
920  * @dev: DRM device
921  * @data: ioctl argument
922  * @file_priv: DRM file for this fd
923  *
924  * Returns the tiling modifier for a BO as set by vc4_set_tiling_ioctl().
925  */
926 int vc4_get_tiling_ioctl(struct drm_device *dev, void *data,
927 			 struct drm_file *file_priv)
928 {
929 	struct drm_vc4_get_tiling *args = data;
930 	struct drm_gem_object *gem_obj;
931 	struct vc4_bo *bo;
932 
933 	if (args->flags != 0 || args->modifier != 0)
934 		return -EINVAL;
935 
936 	gem_obj = drm_gem_object_lookup(file_priv, args->handle);
937 	if (!gem_obj) {
938 		DRM_DEBUG("Failed to look up GEM BO %d\n", args->handle);
939 		return -ENOENT;
940 	}
941 	bo = to_vc4_bo(gem_obj);
942 
943 	if (bo->t_format)
944 		args->modifier = DRM_FORMAT_MOD_BROADCOM_VC4_T_TILED;
945 	else
946 		args->modifier = DRM_FORMAT_MOD_NONE;
947 
948 	drm_gem_object_put(gem_obj);
949 
950 	return 0;
951 }
952 
953 static void vc4_bo_cache_destroy(struct drm_device *dev, void *unused);
954 int vc4_bo_cache_init(struct drm_device *dev)
955 {
956 	struct vc4_dev *vc4 = to_vc4_dev(dev);
957 	int i;
958 
959 	/* Create the initial set of BO labels that the kernel will
960 	 * use.  This lets us avoid a bunch of string reallocation in
961 	 * the kernel's draw and BO allocation paths.
962 	 */
963 	vc4->bo_labels = kcalloc(VC4_BO_TYPE_COUNT, sizeof(*vc4->bo_labels),
964 				 GFP_KERNEL);
965 	if (!vc4->bo_labels)
966 		return -ENOMEM;
967 	vc4->num_labels = VC4_BO_TYPE_COUNT;
968 
969 	BUILD_BUG_ON(ARRAY_SIZE(bo_type_names) != VC4_BO_TYPE_COUNT);
970 	for (i = 0; i < VC4_BO_TYPE_COUNT; i++)
971 		vc4->bo_labels[i].name = bo_type_names[i];
972 
973 	mutex_init(&vc4->bo_lock);
974 
975 	vc4_debugfs_add_file(dev, "bo_stats", vc4_bo_stats_debugfs, NULL);
976 
977 	INIT_LIST_HEAD(&vc4->bo_cache.time_list);
978 
979 	INIT_WORK(&vc4->bo_cache.time_work, vc4_bo_cache_time_work);
980 	timer_setup(&vc4->bo_cache.time_timer, vc4_bo_cache_time_timer, 0);
981 
982 	return drmm_add_action_or_reset(dev, vc4_bo_cache_destroy, NULL);
983 }
984 
985 static void vc4_bo_cache_destroy(struct drm_device *dev, void *unused)
986 {
987 	struct vc4_dev *vc4 = to_vc4_dev(dev);
988 	int i;
989 
990 	del_timer(&vc4->bo_cache.time_timer);
991 	cancel_work_sync(&vc4->bo_cache.time_work);
992 
993 	vc4_bo_cache_purge(dev);
994 
995 	for (i = 0; i < vc4->num_labels; i++) {
996 		if (vc4->bo_labels[i].num_allocated) {
997 			DRM_ERROR("Destroying BO cache with %d %s "
998 				  "BOs still allocated\n",
999 				  vc4->bo_labels[i].num_allocated,
1000 				  vc4->bo_labels[i].name);
1001 		}
1002 
1003 		if (is_user_label(i))
1004 			kfree(vc4->bo_labels[i].name);
1005 	}
1006 	kfree(vc4->bo_labels);
1007 }
1008 
1009 int vc4_label_bo_ioctl(struct drm_device *dev, void *data,
1010 		       struct drm_file *file_priv)
1011 {
1012 	struct vc4_dev *vc4 = to_vc4_dev(dev);
1013 	struct drm_vc4_label_bo *args = data;
1014 	char *name;
1015 	struct drm_gem_object *gem_obj;
1016 	int ret = 0, label;
1017 
1018 	if (!args->len)
1019 		return -EINVAL;
1020 
1021 	name = strndup_user(u64_to_user_ptr(args->name), args->len + 1);
1022 	if (IS_ERR(name))
1023 		return PTR_ERR(name);
1024 
1025 	gem_obj = drm_gem_object_lookup(file_priv, args->handle);
1026 	if (!gem_obj) {
1027 		DRM_ERROR("Failed to look up GEM BO %d\n", args->handle);
1028 		kfree(name);
1029 		return -ENOENT;
1030 	}
1031 
1032 	mutex_lock(&vc4->bo_lock);
1033 	label = vc4_get_user_label(vc4, name);
1034 	if (label != -1)
1035 		vc4_bo_set_label(gem_obj, label);
1036 	else
1037 		ret = -ENOMEM;
1038 	mutex_unlock(&vc4->bo_lock);
1039 
1040 	drm_gem_object_put(gem_obj);
1041 
1042 	return ret;
1043 }
1044