xref: /openbmc/linux/drivers/gpu/drm/vc4/vc4_bo.c (revision 92a76f6d)
1 /*
2  *  Copyright © 2015 Broadcom
3  *
4  * This program is free software; you can redistribute it and/or modify
5  * it under the terms of the GNU General Public License version 2 as
6  * published by the Free Software Foundation.
7  */
8 
9 /* DOC: VC4 GEM BO management support.
10  *
11  * The VC4 GPU architecture (both scanout and rendering) has direct
12  * access to system memory with no MMU in between.  To support it, we
13  * use the GEM CMA helper functions to allocate contiguous ranges of
14  * physical memory for our BOs.
15  *
16  * Since the CMA allocator is very slow, we keep a cache of recently
17  * freed BOs around so that the kernel's allocation of objects for 3D
18  * rendering can return quickly.
19  */
20 
21 #include "vc4_drv.h"
22 #include "uapi/drm/vc4_drm.h"
23 
24 static void vc4_bo_stats_dump(struct vc4_dev *vc4)
25 {
26 	DRM_INFO("num bos allocated: %d\n",
27 		 vc4->bo_stats.num_allocated);
28 	DRM_INFO("size bos allocated: %dkb\n",
29 		 vc4->bo_stats.size_allocated / 1024);
30 	DRM_INFO("num bos used: %d\n",
31 		 vc4->bo_stats.num_allocated - vc4->bo_stats.num_cached);
32 	DRM_INFO("size bos used: %dkb\n",
33 		 (vc4->bo_stats.size_allocated -
34 		  vc4->bo_stats.size_cached) / 1024);
35 	DRM_INFO("num bos cached: %d\n",
36 		 vc4->bo_stats.num_cached);
37 	DRM_INFO("size bos cached: %dkb\n",
38 		 vc4->bo_stats.size_cached / 1024);
39 }
40 
41 #ifdef CONFIG_DEBUG_FS
42 int vc4_bo_stats_debugfs(struct seq_file *m, void *unused)
43 {
44 	struct drm_info_node *node = (struct drm_info_node *)m->private;
45 	struct drm_device *dev = node->minor->dev;
46 	struct vc4_dev *vc4 = to_vc4_dev(dev);
47 	struct vc4_bo_stats stats;
48 
49 	/* Take a snapshot of the current stats with the lock held. */
50 	mutex_lock(&vc4->bo_lock);
51 	stats = vc4->bo_stats;
52 	mutex_unlock(&vc4->bo_lock);
53 
54 	seq_printf(m, "num bos allocated: %d\n",
55 		   stats.num_allocated);
56 	seq_printf(m, "size bos allocated: %dkb\n",
57 		   stats.size_allocated / 1024);
58 	seq_printf(m, "num bos used: %d\n",
59 		   stats.num_allocated - stats.num_cached);
60 	seq_printf(m, "size bos used: %dkb\n",
61 		   (stats.size_allocated - stats.size_cached) / 1024);
62 	seq_printf(m, "num bos cached: %d\n",
63 		   stats.num_cached);
64 	seq_printf(m, "size bos cached: %dkb\n",
65 		   stats.size_cached / 1024);
66 
67 	return 0;
68 }
69 #endif
70 
71 static uint32_t bo_page_index(size_t size)
72 {
73 	return (size / PAGE_SIZE) - 1;
74 }
75 
76 /* Must be called with bo_lock held. */
77 static void vc4_bo_destroy(struct vc4_bo *bo)
78 {
79 	struct drm_gem_object *obj = &bo->base.base;
80 	struct vc4_dev *vc4 = to_vc4_dev(obj->dev);
81 
82 	if (bo->validated_shader) {
83 		kfree(bo->validated_shader->texture_samples);
84 		kfree(bo->validated_shader);
85 		bo->validated_shader = NULL;
86 	}
87 
88 	vc4->bo_stats.num_allocated--;
89 	vc4->bo_stats.size_allocated -= obj->size;
90 	drm_gem_cma_free_object(obj);
91 }
92 
93 /* Must be called with bo_lock held. */
94 static void vc4_bo_remove_from_cache(struct vc4_bo *bo)
95 {
96 	struct drm_gem_object *obj = &bo->base.base;
97 	struct vc4_dev *vc4 = to_vc4_dev(obj->dev);
98 
99 	vc4->bo_stats.num_cached--;
100 	vc4->bo_stats.size_cached -= obj->size;
101 
102 	list_del(&bo->unref_head);
103 	list_del(&bo->size_head);
104 }
105 
106 static struct list_head *vc4_get_cache_list_for_size(struct drm_device *dev,
107 						     size_t size)
108 {
109 	struct vc4_dev *vc4 = to_vc4_dev(dev);
110 	uint32_t page_index = bo_page_index(size);
111 
112 	if (vc4->bo_cache.size_list_size <= page_index) {
113 		uint32_t new_size = max(vc4->bo_cache.size_list_size * 2,
114 					page_index + 1);
115 		struct list_head *new_list;
116 		uint32_t i;
117 
118 		new_list = kmalloc_array(new_size, sizeof(struct list_head),
119 					 GFP_KERNEL);
120 		if (!new_list)
121 			return NULL;
122 
123 		/* Rebase the old cached BO lists to their new list
124 		 * head locations.
125 		 */
126 		for (i = 0; i < vc4->bo_cache.size_list_size; i++) {
127 			struct list_head *old_list =
128 				&vc4->bo_cache.size_list[i];
129 
130 			if (list_empty(old_list))
131 				INIT_LIST_HEAD(&new_list[i]);
132 			else
133 				list_replace(old_list, &new_list[i]);
134 		}
135 		/* And initialize the brand new BO list heads. */
136 		for (i = vc4->bo_cache.size_list_size; i < new_size; i++)
137 			INIT_LIST_HEAD(&new_list[i]);
138 
139 		kfree(vc4->bo_cache.size_list);
140 		vc4->bo_cache.size_list = new_list;
141 		vc4->bo_cache.size_list_size = new_size;
142 	}
143 
144 	return &vc4->bo_cache.size_list[page_index];
145 }
146 
147 void vc4_bo_cache_purge(struct drm_device *dev)
148 {
149 	struct vc4_dev *vc4 = to_vc4_dev(dev);
150 
151 	mutex_lock(&vc4->bo_lock);
152 	while (!list_empty(&vc4->bo_cache.time_list)) {
153 		struct vc4_bo *bo = list_last_entry(&vc4->bo_cache.time_list,
154 						    struct vc4_bo, unref_head);
155 		vc4_bo_remove_from_cache(bo);
156 		vc4_bo_destroy(bo);
157 	}
158 	mutex_unlock(&vc4->bo_lock);
159 }
160 
161 static struct vc4_bo *vc4_bo_get_from_cache(struct drm_device *dev,
162 					    uint32_t size)
163 {
164 	struct vc4_dev *vc4 = to_vc4_dev(dev);
165 	uint32_t page_index = bo_page_index(size);
166 	struct vc4_bo *bo = NULL;
167 
168 	size = roundup(size, PAGE_SIZE);
169 
170 	mutex_lock(&vc4->bo_lock);
171 	if (page_index >= vc4->bo_cache.size_list_size)
172 		goto out;
173 
174 	if (list_empty(&vc4->bo_cache.size_list[page_index]))
175 		goto out;
176 
177 	bo = list_first_entry(&vc4->bo_cache.size_list[page_index],
178 			      struct vc4_bo, size_head);
179 	vc4_bo_remove_from_cache(bo);
180 	kref_init(&bo->base.base.refcount);
181 
182 out:
183 	mutex_unlock(&vc4->bo_lock);
184 	return bo;
185 }
186 
187 /**
188  * vc4_gem_create_object - Implementation of driver->gem_create_object.
189  *
190  * This lets the CMA helpers allocate object structs for us, and keep
191  * our BO stats correct.
192  */
193 struct drm_gem_object *vc4_create_object(struct drm_device *dev, size_t size)
194 {
195 	struct vc4_dev *vc4 = to_vc4_dev(dev);
196 	struct vc4_bo *bo;
197 
198 	bo = kzalloc(sizeof(*bo), GFP_KERNEL);
199 	if (!bo)
200 		return ERR_PTR(-ENOMEM);
201 
202 	mutex_lock(&vc4->bo_lock);
203 	vc4->bo_stats.num_allocated++;
204 	vc4->bo_stats.size_allocated += size;
205 	mutex_unlock(&vc4->bo_lock);
206 
207 	return &bo->base.base;
208 }
209 
210 struct vc4_bo *vc4_bo_create(struct drm_device *dev, size_t unaligned_size,
211 			     bool from_cache)
212 {
213 	size_t size = roundup(unaligned_size, PAGE_SIZE);
214 	struct vc4_dev *vc4 = to_vc4_dev(dev);
215 	struct drm_gem_cma_object *cma_obj;
216 
217 	if (size == 0)
218 		return ERR_PTR(-EINVAL);
219 
220 	/* First, try to get a vc4_bo from the kernel BO cache. */
221 	if (from_cache) {
222 		struct vc4_bo *bo = vc4_bo_get_from_cache(dev, size);
223 
224 		if (bo)
225 			return bo;
226 	}
227 
228 	cma_obj = drm_gem_cma_create(dev, size);
229 	if (IS_ERR(cma_obj)) {
230 		/*
231 		 * If we've run out of CMA memory, kill the cache of
232 		 * CMA allocations we've got laying around and try again.
233 		 */
234 		vc4_bo_cache_purge(dev);
235 
236 		cma_obj = drm_gem_cma_create(dev, size);
237 		if (IS_ERR(cma_obj)) {
238 			DRM_ERROR("Failed to allocate from CMA:\n");
239 			vc4_bo_stats_dump(vc4);
240 			return ERR_PTR(-ENOMEM);
241 		}
242 	}
243 
244 	return to_vc4_bo(&cma_obj->base);
245 }
246 
247 int vc4_dumb_create(struct drm_file *file_priv,
248 		    struct drm_device *dev,
249 		    struct drm_mode_create_dumb *args)
250 {
251 	int min_pitch = DIV_ROUND_UP(args->width * args->bpp, 8);
252 	struct vc4_bo *bo = NULL;
253 	int ret;
254 
255 	if (args->pitch < min_pitch)
256 		args->pitch = min_pitch;
257 
258 	if (args->size < args->pitch * args->height)
259 		args->size = args->pitch * args->height;
260 
261 	bo = vc4_bo_create(dev, args->size, false);
262 	if (IS_ERR(bo))
263 		return PTR_ERR(bo);
264 
265 	ret = drm_gem_handle_create(file_priv, &bo->base.base, &args->handle);
266 	drm_gem_object_unreference_unlocked(&bo->base.base);
267 
268 	return ret;
269 }
270 
271 /* Must be called with bo_lock held. */
272 static void vc4_bo_cache_free_old(struct drm_device *dev)
273 {
274 	struct vc4_dev *vc4 = to_vc4_dev(dev);
275 	unsigned long expire_time = jiffies - msecs_to_jiffies(1000);
276 
277 	while (!list_empty(&vc4->bo_cache.time_list)) {
278 		struct vc4_bo *bo = list_last_entry(&vc4->bo_cache.time_list,
279 						    struct vc4_bo, unref_head);
280 		if (time_before(expire_time, bo->free_time)) {
281 			mod_timer(&vc4->bo_cache.time_timer,
282 				  round_jiffies_up(jiffies +
283 						   msecs_to_jiffies(1000)));
284 			return;
285 		}
286 
287 		vc4_bo_remove_from_cache(bo);
288 		vc4_bo_destroy(bo);
289 	}
290 }
291 
292 /* Called on the last userspace/kernel unreference of the BO.  Returns
293  * it to the BO cache if possible, otherwise frees it.
294  *
295  * Note that this is called with the struct_mutex held.
296  */
297 void vc4_free_object(struct drm_gem_object *gem_bo)
298 {
299 	struct drm_device *dev = gem_bo->dev;
300 	struct vc4_dev *vc4 = to_vc4_dev(dev);
301 	struct vc4_bo *bo = to_vc4_bo(gem_bo);
302 	struct list_head *cache_list;
303 
304 	mutex_lock(&vc4->bo_lock);
305 	/* If the object references someone else's memory, we can't cache it.
306 	 */
307 	if (gem_bo->import_attach) {
308 		vc4_bo_destroy(bo);
309 		goto out;
310 	}
311 
312 	/* Don't cache if it was publicly named. */
313 	if (gem_bo->name) {
314 		vc4_bo_destroy(bo);
315 		goto out;
316 	}
317 
318 	cache_list = vc4_get_cache_list_for_size(dev, gem_bo->size);
319 	if (!cache_list) {
320 		vc4_bo_destroy(bo);
321 		goto out;
322 	}
323 
324 	if (bo->validated_shader) {
325 		kfree(bo->validated_shader->texture_samples);
326 		kfree(bo->validated_shader);
327 		bo->validated_shader = NULL;
328 	}
329 
330 	bo->free_time = jiffies;
331 	list_add(&bo->size_head, cache_list);
332 	list_add(&bo->unref_head, &vc4->bo_cache.time_list);
333 
334 	vc4->bo_stats.num_cached++;
335 	vc4->bo_stats.size_cached += gem_bo->size;
336 
337 	vc4_bo_cache_free_old(dev);
338 
339 out:
340 	mutex_unlock(&vc4->bo_lock);
341 }
342 
343 static void vc4_bo_cache_time_work(struct work_struct *work)
344 {
345 	struct vc4_dev *vc4 =
346 		container_of(work, struct vc4_dev, bo_cache.time_work);
347 	struct drm_device *dev = vc4->dev;
348 
349 	mutex_lock(&vc4->bo_lock);
350 	vc4_bo_cache_free_old(dev);
351 	mutex_unlock(&vc4->bo_lock);
352 }
353 
354 static void vc4_bo_cache_time_timer(unsigned long data)
355 {
356 	struct drm_device *dev = (struct drm_device *)data;
357 	struct vc4_dev *vc4 = to_vc4_dev(dev);
358 
359 	schedule_work(&vc4->bo_cache.time_work);
360 }
361 
362 struct dma_buf *
363 vc4_prime_export(struct drm_device *dev, struct drm_gem_object *obj, int flags)
364 {
365 	struct vc4_bo *bo = to_vc4_bo(obj);
366 
367 	if (bo->validated_shader) {
368 		DRM_ERROR("Attempting to export shader BO\n");
369 		return ERR_PTR(-EINVAL);
370 	}
371 
372 	return drm_gem_prime_export(dev, obj, flags);
373 }
374 
375 int vc4_mmap(struct file *filp, struct vm_area_struct *vma)
376 {
377 	struct drm_gem_object *gem_obj;
378 	struct vc4_bo *bo;
379 	int ret;
380 
381 	ret = drm_gem_mmap(filp, vma);
382 	if (ret)
383 		return ret;
384 
385 	gem_obj = vma->vm_private_data;
386 	bo = to_vc4_bo(gem_obj);
387 
388 	if (bo->validated_shader && (vma->vm_flags & VM_WRITE)) {
389 		DRM_ERROR("mmaping of shader BOs for writing not allowed.\n");
390 		return -EINVAL;
391 	}
392 
393 	/*
394 	 * Clear the VM_PFNMAP flag that was set by drm_gem_mmap(), and set the
395 	 * vm_pgoff (used as a fake buffer offset by DRM) to 0 as we want to map
396 	 * the whole buffer.
397 	 */
398 	vma->vm_flags &= ~VM_PFNMAP;
399 	vma->vm_pgoff = 0;
400 
401 	ret = dma_mmap_wc(bo->base.base.dev->dev, vma, bo->base.vaddr,
402 			  bo->base.paddr, vma->vm_end - vma->vm_start);
403 	if (ret)
404 		drm_gem_vm_close(vma);
405 
406 	return ret;
407 }
408 
409 int vc4_prime_mmap(struct drm_gem_object *obj, struct vm_area_struct *vma)
410 {
411 	struct vc4_bo *bo = to_vc4_bo(obj);
412 
413 	if (bo->validated_shader && (vma->vm_flags & VM_WRITE)) {
414 		DRM_ERROR("mmaping of shader BOs for writing not allowed.\n");
415 		return -EINVAL;
416 	}
417 
418 	return drm_gem_cma_prime_mmap(obj, vma);
419 }
420 
421 void *vc4_prime_vmap(struct drm_gem_object *obj)
422 {
423 	struct vc4_bo *bo = to_vc4_bo(obj);
424 
425 	if (bo->validated_shader) {
426 		DRM_ERROR("mmaping of shader BOs not allowed.\n");
427 		return ERR_PTR(-EINVAL);
428 	}
429 
430 	return drm_gem_cma_prime_vmap(obj);
431 }
432 
433 int vc4_create_bo_ioctl(struct drm_device *dev, void *data,
434 			struct drm_file *file_priv)
435 {
436 	struct drm_vc4_create_bo *args = data;
437 	struct vc4_bo *bo = NULL;
438 	int ret;
439 
440 	/*
441 	 * We can't allocate from the BO cache, because the BOs don't
442 	 * get zeroed, and that might leak data between users.
443 	 */
444 	bo = vc4_bo_create(dev, args->size, false);
445 	if (IS_ERR(bo))
446 		return PTR_ERR(bo);
447 
448 	ret = drm_gem_handle_create(file_priv, &bo->base.base, &args->handle);
449 	drm_gem_object_unreference_unlocked(&bo->base.base);
450 
451 	return ret;
452 }
453 
454 int vc4_mmap_bo_ioctl(struct drm_device *dev, void *data,
455 		      struct drm_file *file_priv)
456 {
457 	struct drm_vc4_mmap_bo *args = data;
458 	struct drm_gem_object *gem_obj;
459 
460 	gem_obj = drm_gem_object_lookup(dev, file_priv, args->handle);
461 	if (!gem_obj) {
462 		DRM_ERROR("Failed to look up GEM BO %d\n", args->handle);
463 		return -EINVAL;
464 	}
465 
466 	/* The mmap offset was set up at BO allocation time. */
467 	args->offset = drm_vma_node_offset_addr(&gem_obj->vma_node);
468 
469 	drm_gem_object_unreference_unlocked(gem_obj);
470 	return 0;
471 }
472 
473 int
474 vc4_create_shader_bo_ioctl(struct drm_device *dev, void *data,
475 			   struct drm_file *file_priv)
476 {
477 	struct drm_vc4_create_shader_bo *args = data;
478 	struct vc4_bo *bo = NULL;
479 	int ret;
480 
481 	if (args->size == 0)
482 		return -EINVAL;
483 
484 	if (args->size % sizeof(u64) != 0)
485 		return -EINVAL;
486 
487 	if (args->flags != 0) {
488 		DRM_INFO("Unknown flags set: 0x%08x\n", args->flags);
489 		return -EINVAL;
490 	}
491 
492 	if (args->pad != 0) {
493 		DRM_INFO("Pad set: 0x%08x\n", args->pad);
494 		return -EINVAL;
495 	}
496 
497 	bo = vc4_bo_create(dev, args->size, true);
498 	if (IS_ERR(bo))
499 		return PTR_ERR(bo);
500 
501 	if (copy_from_user(bo->base.vaddr,
502 			     (void __user *)(uintptr_t)args->data,
503 			     args->size)) {
504 		ret = -EFAULT;
505 		goto fail;
506 	}
507 	/* Clear the rest of the memory from allocating from the BO
508 	 * cache.
509 	 */
510 	memset(bo->base.vaddr + args->size, 0,
511 	       bo->base.base.size - args->size);
512 
513 	bo->validated_shader = vc4_validate_shader(&bo->base);
514 	if (!bo->validated_shader) {
515 		ret = -EINVAL;
516 		goto fail;
517 	}
518 
519 	/* We have to create the handle after validation, to avoid
520 	 * races for users to do doing things like mmap the shader BO.
521 	 */
522 	ret = drm_gem_handle_create(file_priv, &bo->base.base, &args->handle);
523 
524  fail:
525 	drm_gem_object_unreference_unlocked(&bo->base.base);
526 
527 	return ret;
528 }
529 
530 void vc4_bo_cache_init(struct drm_device *dev)
531 {
532 	struct vc4_dev *vc4 = to_vc4_dev(dev);
533 
534 	mutex_init(&vc4->bo_lock);
535 
536 	INIT_LIST_HEAD(&vc4->bo_cache.time_list);
537 
538 	INIT_WORK(&vc4->bo_cache.time_work, vc4_bo_cache_time_work);
539 	setup_timer(&vc4->bo_cache.time_timer,
540 		    vc4_bo_cache_time_timer,
541 		    (unsigned long)dev);
542 }
543 
544 void vc4_bo_cache_destroy(struct drm_device *dev)
545 {
546 	struct vc4_dev *vc4 = to_vc4_dev(dev);
547 
548 	del_timer(&vc4->bo_cache.time_timer);
549 	cancel_work_sync(&vc4->bo_cache.time_work);
550 
551 	vc4_bo_cache_purge(dev);
552 
553 	if (vc4->bo_stats.num_allocated) {
554 		DRM_ERROR("Destroying BO cache while BOs still allocated:\n");
555 		vc4_bo_stats_dump(vc4);
556 	}
557 }
558