1 // SPDX-License-Identifier: GPL-2.0-or-later
2 /*
3  * drm gem framebuffer helper functions
4  *
5  * Copyright (C) 2017 Noralf Trønnes
6  */
7 
8 #include <linux/slab.h>
9 #include <linux/module.h>
10 
11 #include <drm/drm_damage_helper.h>
12 #include <drm/drm_drv.h>
13 #include <drm/drm_fourcc.h>
14 #include <drm/drm_framebuffer.h>
15 #include <drm/drm_gem.h>
16 #include <drm/drm_gem_framebuffer_helper.h>
17 #include <drm/drm_modeset_helper.h>
18 
19 #include "drm_internal.h"
20 
21 MODULE_IMPORT_NS(DMA_BUF);
22 
23 #define AFBC_HEADER_SIZE		16
24 #define AFBC_TH_LAYOUT_ALIGNMENT	8
25 #define AFBC_HDR_ALIGN			64
26 #define AFBC_SUPERBLOCK_PIXELS		256
27 #define AFBC_SUPERBLOCK_ALIGNMENT	128
28 #define AFBC_TH_BODY_START_ALIGNMENT	4096
29 
30 /**
31  * DOC: overview
32  *
33  * This library provides helpers for drivers that don't subclass
34  * &drm_framebuffer and use &drm_gem_object for their backing storage.
35  *
36  * Drivers without additional needs to validate framebuffers can simply use
37  * drm_gem_fb_create() and everything is wired up automatically. Other drivers
38  * can use all parts independently.
39  */
40 
41 /**
42  * drm_gem_fb_get_obj() - Get GEM object backing the framebuffer
43  * @fb: Framebuffer
44  * @plane: Plane index
45  *
46  * No additional reference is taken beyond the one that the &drm_frambuffer
47  * already holds.
48  *
49  * Returns:
50  * Pointer to &drm_gem_object for the given framebuffer and plane index or NULL
51  * if it does not exist.
52  */
53 struct drm_gem_object *drm_gem_fb_get_obj(struct drm_framebuffer *fb,
54 					  unsigned int plane)
55 {
56 	struct drm_device *dev = fb->dev;
57 
58 	if (drm_WARN_ON_ONCE(dev, plane >= ARRAY_SIZE(fb->obj)))
59 		return NULL;
60 	else if (drm_WARN_ON_ONCE(dev, !fb->obj[plane]))
61 		return NULL;
62 
63 	return fb->obj[plane];
64 }
65 EXPORT_SYMBOL_GPL(drm_gem_fb_get_obj);
66 
67 static int
68 drm_gem_fb_init(struct drm_device *dev,
69 		 struct drm_framebuffer *fb,
70 		 const struct drm_mode_fb_cmd2 *mode_cmd,
71 		 struct drm_gem_object **obj, unsigned int num_planes,
72 		 const struct drm_framebuffer_funcs *funcs)
73 {
74 	unsigned int i;
75 	int ret;
76 
77 	drm_helper_mode_fill_fb_struct(dev, fb, mode_cmd);
78 
79 	for (i = 0; i < num_planes; i++)
80 		fb->obj[i] = obj[i];
81 
82 	ret = drm_framebuffer_init(dev, fb, funcs);
83 	if (ret)
84 		drm_err(dev, "Failed to init framebuffer: %d\n", ret);
85 
86 	return ret;
87 }
88 
89 /**
90  * drm_gem_fb_destroy - Free GEM backed framebuffer
91  * @fb: Framebuffer
92  *
93  * Frees a GEM backed framebuffer with its backing buffer(s) and the structure
94  * itself. Drivers can use this as their &drm_framebuffer_funcs->destroy
95  * callback.
96  */
97 void drm_gem_fb_destroy(struct drm_framebuffer *fb)
98 {
99 	unsigned int i;
100 
101 	for (i = 0; i < fb->format->num_planes; i++)
102 		drm_gem_object_put(fb->obj[i]);
103 
104 	drm_framebuffer_cleanup(fb);
105 	kfree(fb);
106 }
107 EXPORT_SYMBOL(drm_gem_fb_destroy);
108 
109 /**
110  * drm_gem_fb_create_handle - Create handle for GEM backed framebuffer
111  * @fb: Framebuffer
112  * @file: DRM file to register the handle for
113  * @handle: Pointer to return the created handle
114  *
115  * This function creates a handle for the GEM object backing the framebuffer.
116  * Drivers can use this as their &drm_framebuffer_funcs->create_handle
117  * callback. The GETFB IOCTL calls into this callback.
118  *
119  * Returns:
120  * 0 on success or a negative error code on failure.
121  */
122 int drm_gem_fb_create_handle(struct drm_framebuffer *fb, struct drm_file *file,
123 			     unsigned int *handle)
124 {
125 	return drm_gem_handle_create(file, fb->obj[0], handle);
126 }
127 EXPORT_SYMBOL(drm_gem_fb_create_handle);
128 
129 /**
130  * drm_gem_fb_init_with_funcs() - Helper function for implementing
131  *				  &drm_mode_config_funcs.fb_create
132  *				  callback in cases when the driver
133  *				  allocates a subclass of
134  *				  struct drm_framebuffer
135  * @dev: DRM device
136  * @fb: framebuffer object
137  * @file: DRM file that holds the GEM handle(s) backing the framebuffer
138  * @mode_cmd: Metadata from the userspace framebuffer creation request
139  * @funcs: vtable to be used for the new framebuffer object
140  *
141  * This function can be used to set &drm_framebuffer_funcs for drivers that need
142  * custom framebuffer callbacks. Use drm_gem_fb_create() if you don't need to
143  * change &drm_framebuffer_funcs. The function does buffer size validation.
144  * The buffer size validation is for a general case, though, so users should
145  * pay attention to the checks being appropriate for them or, at least,
146  * non-conflicting.
147  *
148  * Returns:
149  * Zero or a negative error code.
150  */
151 int drm_gem_fb_init_with_funcs(struct drm_device *dev,
152 			       struct drm_framebuffer *fb,
153 			       struct drm_file *file,
154 			       const struct drm_mode_fb_cmd2 *mode_cmd,
155 			       const struct drm_framebuffer_funcs *funcs)
156 {
157 	const struct drm_format_info *info;
158 	struct drm_gem_object *objs[DRM_FORMAT_MAX_PLANES];
159 	unsigned int i;
160 	int ret;
161 
162 	info = drm_get_format_info(dev, mode_cmd);
163 	if (!info) {
164 		drm_dbg_kms(dev, "Failed to get FB format info\n");
165 		return -EINVAL;
166 	}
167 
168 	if (drm_drv_uses_atomic_modeset(dev) &&
169 	    !drm_any_plane_has_format(dev, mode_cmd->pixel_format,
170 				      mode_cmd->modifier[0])) {
171 		drm_dbg(dev, "Unsupported pixel format %p4cc / modifier 0x%llx\n",
172 			&mode_cmd->pixel_format, mode_cmd->modifier[0]);
173 		return -EINVAL;
174 	}
175 
176 	for (i = 0; i < info->num_planes; i++) {
177 		unsigned int width = mode_cmd->width / (i ? info->hsub : 1);
178 		unsigned int height = mode_cmd->height / (i ? info->vsub : 1);
179 		unsigned int min_size;
180 
181 		objs[i] = drm_gem_object_lookup(file, mode_cmd->handles[i]);
182 		if (!objs[i]) {
183 			drm_dbg_kms(dev, "Failed to lookup GEM object\n");
184 			ret = -ENOENT;
185 			goto err_gem_object_put;
186 		}
187 
188 		min_size = (height - 1) * mode_cmd->pitches[i]
189 			 + drm_format_info_min_pitch(info, i, width)
190 			 + mode_cmd->offsets[i];
191 
192 		if (objs[i]->size < min_size) {
193 			drm_dbg_kms(dev,
194 				    "GEM object size (%zu) smaller than minimum size (%u) for plane %d\n",
195 				    objs[i]->size, min_size, i);
196 			drm_gem_object_put(objs[i]);
197 			ret = -EINVAL;
198 			goto err_gem_object_put;
199 		}
200 	}
201 
202 	ret = drm_gem_fb_init(dev, fb, mode_cmd, objs, i, funcs);
203 	if (ret)
204 		goto err_gem_object_put;
205 
206 	return 0;
207 
208 err_gem_object_put:
209 	while (i > 0) {
210 		--i;
211 		drm_gem_object_put(objs[i]);
212 	}
213 	return ret;
214 }
215 EXPORT_SYMBOL_GPL(drm_gem_fb_init_with_funcs);
216 
217 /**
218  * drm_gem_fb_create_with_funcs() - Helper function for the
219  *                                  &drm_mode_config_funcs.fb_create
220  *                                  callback
221  * @dev: DRM device
222  * @file: DRM file that holds the GEM handle(s) backing the framebuffer
223  * @mode_cmd: Metadata from the userspace framebuffer creation request
224  * @funcs: vtable to be used for the new framebuffer object
225  *
226  * This function can be used to set &drm_framebuffer_funcs for drivers that need
227  * custom framebuffer callbacks. Use drm_gem_fb_create() if you don't need to
228  * change &drm_framebuffer_funcs. The function does buffer size validation.
229  *
230  * Returns:
231  * Pointer to a &drm_framebuffer on success or an error pointer on failure.
232  */
233 struct drm_framebuffer *
234 drm_gem_fb_create_with_funcs(struct drm_device *dev, struct drm_file *file,
235 			     const struct drm_mode_fb_cmd2 *mode_cmd,
236 			     const struct drm_framebuffer_funcs *funcs)
237 {
238 	struct drm_framebuffer *fb;
239 	int ret;
240 
241 	fb = kzalloc(sizeof(*fb), GFP_KERNEL);
242 	if (!fb)
243 		return ERR_PTR(-ENOMEM);
244 
245 	ret = drm_gem_fb_init_with_funcs(dev, fb, file, mode_cmd, funcs);
246 	if (ret) {
247 		kfree(fb);
248 		return ERR_PTR(ret);
249 	}
250 
251 	return fb;
252 }
253 EXPORT_SYMBOL_GPL(drm_gem_fb_create_with_funcs);
254 
255 static const struct drm_framebuffer_funcs drm_gem_fb_funcs = {
256 	.destroy	= drm_gem_fb_destroy,
257 	.create_handle	= drm_gem_fb_create_handle,
258 };
259 
260 /**
261  * drm_gem_fb_create() - Helper function for the
262  *                       &drm_mode_config_funcs.fb_create callback
263  * @dev: DRM device
264  * @file: DRM file that holds the GEM handle(s) backing the framebuffer
265  * @mode_cmd: Metadata from the userspace framebuffer creation request
266  *
267  * This function creates a new framebuffer object described by
268  * &drm_mode_fb_cmd2. This description includes handles for the buffer(s)
269  * backing the framebuffer.
270  *
271  * If your hardware has special alignment or pitch requirements these should be
272  * checked before calling this function. The function does buffer size
273  * validation. Use drm_gem_fb_create_with_dirty() if you need framebuffer
274  * flushing.
275  *
276  * Drivers can use this as their &drm_mode_config_funcs.fb_create callback.
277  * The ADDFB2 IOCTL calls into this callback.
278  *
279  * Returns:
280  * Pointer to a &drm_framebuffer on success or an error pointer on failure.
281  */
282 struct drm_framebuffer *
283 drm_gem_fb_create(struct drm_device *dev, struct drm_file *file,
284 		  const struct drm_mode_fb_cmd2 *mode_cmd)
285 {
286 	return drm_gem_fb_create_with_funcs(dev, file, mode_cmd,
287 					    &drm_gem_fb_funcs);
288 }
289 EXPORT_SYMBOL_GPL(drm_gem_fb_create);
290 
291 static const struct drm_framebuffer_funcs drm_gem_fb_funcs_dirtyfb = {
292 	.destroy	= drm_gem_fb_destroy,
293 	.create_handle	= drm_gem_fb_create_handle,
294 	.dirty		= drm_atomic_helper_dirtyfb,
295 };
296 
297 /**
298  * drm_gem_fb_create_with_dirty() - Helper function for the
299  *                       &drm_mode_config_funcs.fb_create callback
300  * @dev: DRM device
301  * @file: DRM file that holds the GEM handle(s) backing the framebuffer
302  * @mode_cmd: Metadata from the userspace framebuffer creation request
303  *
304  * This function creates a new framebuffer object described by
305  * &drm_mode_fb_cmd2. This description includes handles for the buffer(s)
306  * backing the framebuffer. drm_atomic_helper_dirtyfb() is used for the dirty
307  * callback giving framebuffer flushing through the atomic machinery. Use
308  * drm_gem_fb_create() if you don't need the dirty callback.
309  * The function does buffer size validation.
310  *
311  * Drivers should also call drm_plane_enable_fb_damage_clips() on all planes
312  * to enable userspace to use damage clips also with the ATOMIC IOCTL.
313  *
314  * Drivers can use this as their &drm_mode_config_funcs.fb_create callback.
315  * The ADDFB2 IOCTL calls into this callback.
316  *
317  * Returns:
318  * Pointer to a &drm_framebuffer on success or an error pointer on failure.
319  */
320 struct drm_framebuffer *
321 drm_gem_fb_create_with_dirty(struct drm_device *dev, struct drm_file *file,
322 			     const struct drm_mode_fb_cmd2 *mode_cmd)
323 {
324 	return drm_gem_fb_create_with_funcs(dev, file, mode_cmd,
325 					    &drm_gem_fb_funcs_dirtyfb);
326 }
327 EXPORT_SYMBOL_GPL(drm_gem_fb_create_with_dirty);
328 
329 /**
330  * drm_gem_fb_vmap - maps all framebuffer BOs into kernel address space
331  * @fb: the framebuffer
332  * @map: returns the mapping's address for each BO
333  * @data: returns the data address for each BO, can be NULL
334  *
335  * This function maps all buffer objects of the given framebuffer into
336  * kernel address space and stores them in struct iosys_map. If the
337  * mapping operation fails for one of the BOs, the function unmaps the
338  * already established mappings automatically.
339  *
340  * Callers that want to access a BO's stored data should pass @data.
341  * The argument returns the addresses of the data stored in each BO. This
342  * is different from @map if the framebuffer's offsets field is non-zero.
343  *
344  * Both, @map and @data, must each refer to arrays with at least
345  * fb->format->num_planes elements.
346  *
347  * See drm_gem_fb_vunmap() for unmapping.
348  *
349  * Returns:
350  * 0 on success, or a negative errno code otherwise.
351  */
352 int drm_gem_fb_vmap(struct drm_framebuffer *fb, struct iosys_map *map,
353 		    struct iosys_map *data)
354 {
355 	struct drm_gem_object *obj;
356 	unsigned int i;
357 	int ret;
358 
359 	for (i = 0; i < fb->format->num_planes; ++i) {
360 		obj = drm_gem_fb_get_obj(fb, i);
361 		if (!obj) {
362 			ret = -EINVAL;
363 			goto err_drm_gem_vunmap;
364 		}
365 		ret = drm_gem_vmap_unlocked(obj, &map[i]);
366 		if (ret)
367 			goto err_drm_gem_vunmap;
368 	}
369 
370 	if (data) {
371 		for (i = 0; i < fb->format->num_planes; ++i) {
372 			memcpy(&data[i], &map[i], sizeof(data[i]));
373 			if (iosys_map_is_null(&data[i]))
374 				continue;
375 			iosys_map_incr(&data[i], fb->offsets[i]);
376 		}
377 	}
378 
379 	return 0;
380 
381 err_drm_gem_vunmap:
382 	while (i) {
383 		--i;
384 		obj = drm_gem_fb_get_obj(fb, i);
385 		if (!obj)
386 			continue;
387 		drm_gem_vunmap_unlocked(obj, &map[i]);
388 	}
389 	return ret;
390 }
391 EXPORT_SYMBOL(drm_gem_fb_vmap);
392 
393 /**
394  * drm_gem_fb_vunmap - unmaps framebuffer BOs from kernel address space
395  * @fb: the framebuffer
396  * @map: mapping addresses as returned by drm_gem_fb_vmap()
397  *
398  * This function unmaps all buffer objects of the given framebuffer.
399  *
400  * See drm_gem_fb_vmap() for more information.
401  */
402 void drm_gem_fb_vunmap(struct drm_framebuffer *fb, struct iosys_map *map)
403 {
404 	unsigned int i = fb->format->num_planes;
405 	struct drm_gem_object *obj;
406 
407 	while (i) {
408 		--i;
409 		obj = drm_gem_fb_get_obj(fb, i);
410 		if (!obj)
411 			continue;
412 		if (iosys_map_is_null(&map[i]))
413 			continue;
414 		drm_gem_vunmap_unlocked(obj, &map[i]);
415 	}
416 }
417 EXPORT_SYMBOL(drm_gem_fb_vunmap);
418 
419 static void __drm_gem_fb_end_cpu_access(struct drm_framebuffer *fb, enum dma_data_direction dir,
420 					unsigned int num_planes)
421 {
422 	struct dma_buf_attachment *import_attach;
423 	struct drm_gem_object *obj;
424 	int ret;
425 
426 	while (num_planes) {
427 		--num_planes;
428 		obj = drm_gem_fb_get_obj(fb, num_planes);
429 		if (!obj)
430 			continue;
431 		import_attach = obj->import_attach;
432 		if (!import_attach)
433 			continue;
434 		ret = dma_buf_end_cpu_access(import_attach->dmabuf, dir);
435 		if (ret)
436 			drm_err(fb->dev, "dma_buf_end_cpu_access(%u, %d) failed: %d\n",
437 				ret, num_planes, dir);
438 	}
439 }
440 
441 /**
442  * drm_gem_fb_begin_cpu_access - prepares GEM buffer objects for CPU access
443  * @fb: the framebuffer
444  * @dir: access mode
445  *
446  * Prepares a framebuffer's GEM buffer objects for CPU access. This function
447  * must be called before accessing the BO data within the kernel. For imported
448  * BOs, the function calls dma_buf_begin_cpu_access().
449  *
450  * See drm_gem_fb_end_cpu_access() for signalling the end of CPU access.
451  *
452  * Returns:
453  * 0 on success, or a negative errno code otherwise.
454  */
455 int drm_gem_fb_begin_cpu_access(struct drm_framebuffer *fb, enum dma_data_direction dir)
456 {
457 	struct dma_buf_attachment *import_attach;
458 	struct drm_gem_object *obj;
459 	unsigned int i;
460 	int ret;
461 
462 	for (i = 0; i < fb->format->num_planes; ++i) {
463 		obj = drm_gem_fb_get_obj(fb, i);
464 		if (!obj) {
465 			ret = -EINVAL;
466 			goto err___drm_gem_fb_end_cpu_access;
467 		}
468 		import_attach = obj->import_attach;
469 		if (!import_attach)
470 			continue;
471 		ret = dma_buf_begin_cpu_access(import_attach->dmabuf, dir);
472 		if (ret)
473 			goto err___drm_gem_fb_end_cpu_access;
474 	}
475 
476 	return 0;
477 
478 err___drm_gem_fb_end_cpu_access:
479 	__drm_gem_fb_end_cpu_access(fb, dir, i);
480 	return ret;
481 }
482 EXPORT_SYMBOL(drm_gem_fb_begin_cpu_access);
483 
484 /**
485  * drm_gem_fb_end_cpu_access - signals end of CPU access to GEM buffer objects
486  * @fb: the framebuffer
487  * @dir: access mode
488  *
489  * Signals the end of CPU access to the given framebuffer's GEM buffer objects. This
490  * function must be paired with a corresponding call to drm_gem_fb_begin_cpu_access().
491  * For imported BOs, the function calls dma_buf_end_cpu_access().
492  *
493  * See also drm_gem_fb_begin_cpu_access().
494  */
495 void drm_gem_fb_end_cpu_access(struct drm_framebuffer *fb, enum dma_data_direction dir)
496 {
497 	__drm_gem_fb_end_cpu_access(fb, dir, fb->format->num_planes);
498 }
499 EXPORT_SYMBOL(drm_gem_fb_end_cpu_access);
500 
501 // TODO Drop this function and replace by drm_format_info_bpp() once all
502 // DRM_FORMAT_* provide proper block info in drivers/gpu/drm/drm_fourcc.c
503 static __u32 drm_gem_afbc_get_bpp(struct drm_device *dev,
504 				  const struct drm_mode_fb_cmd2 *mode_cmd)
505 {
506 	const struct drm_format_info *info;
507 
508 	info = drm_get_format_info(dev, mode_cmd);
509 
510 	switch (info->format) {
511 	case DRM_FORMAT_YUV420_8BIT:
512 		return 12;
513 	case DRM_FORMAT_YUV420_10BIT:
514 		return 15;
515 	case DRM_FORMAT_VUY101010:
516 		return 30;
517 	default:
518 		return drm_format_info_bpp(info, 0);
519 	}
520 }
521 
522 static int drm_gem_afbc_min_size(struct drm_device *dev,
523 				 const struct drm_mode_fb_cmd2 *mode_cmd,
524 				 struct drm_afbc_framebuffer *afbc_fb)
525 {
526 	__u32 n_blocks, w_alignment, h_alignment, hdr_alignment;
527 	/* remove bpp when all users properly encode cpp in drm_format_info */
528 	__u32 bpp;
529 
530 	switch (mode_cmd->modifier[0] & AFBC_FORMAT_MOD_BLOCK_SIZE_MASK) {
531 	case AFBC_FORMAT_MOD_BLOCK_SIZE_16x16:
532 		afbc_fb->block_width = 16;
533 		afbc_fb->block_height = 16;
534 		break;
535 	case AFBC_FORMAT_MOD_BLOCK_SIZE_32x8:
536 		afbc_fb->block_width = 32;
537 		afbc_fb->block_height = 8;
538 		break;
539 	/* no user exists yet - fall through */
540 	case AFBC_FORMAT_MOD_BLOCK_SIZE_64x4:
541 	case AFBC_FORMAT_MOD_BLOCK_SIZE_32x8_64x4:
542 	default:
543 		drm_dbg_kms(dev, "Invalid AFBC_FORMAT_MOD_BLOCK_SIZE: %lld.\n",
544 			    mode_cmd->modifier[0]
545 			    & AFBC_FORMAT_MOD_BLOCK_SIZE_MASK);
546 		return -EINVAL;
547 	}
548 
549 	/* tiled header afbc */
550 	w_alignment = afbc_fb->block_width;
551 	h_alignment = afbc_fb->block_height;
552 	hdr_alignment = AFBC_HDR_ALIGN;
553 	if (mode_cmd->modifier[0] & AFBC_FORMAT_MOD_TILED) {
554 		w_alignment *= AFBC_TH_LAYOUT_ALIGNMENT;
555 		h_alignment *= AFBC_TH_LAYOUT_ALIGNMENT;
556 		hdr_alignment = AFBC_TH_BODY_START_ALIGNMENT;
557 	}
558 
559 	afbc_fb->aligned_width = ALIGN(mode_cmd->width, w_alignment);
560 	afbc_fb->aligned_height = ALIGN(mode_cmd->height, h_alignment);
561 	afbc_fb->offset = mode_cmd->offsets[0];
562 
563 	bpp = drm_gem_afbc_get_bpp(dev, mode_cmd);
564 	if (!bpp) {
565 		drm_dbg_kms(dev, "Invalid AFBC bpp value: %d\n", bpp);
566 		return -EINVAL;
567 	}
568 
569 	n_blocks = (afbc_fb->aligned_width * afbc_fb->aligned_height)
570 		   / AFBC_SUPERBLOCK_PIXELS;
571 	afbc_fb->afbc_size = ALIGN(n_blocks * AFBC_HEADER_SIZE, hdr_alignment);
572 	afbc_fb->afbc_size += n_blocks * ALIGN(bpp * AFBC_SUPERBLOCK_PIXELS / 8,
573 					       AFBC_SUPERBLOCK_ALIGNMENT);
574 
575 	return 0;
576 }
577 
578 /**
579  * drm_gem_fb_afbc_init() - Helper function for drivers using afbc to
580  *			    fill and validate all the afbc-specific
581  *			    struct drm_afbc_framebuffer members
582  *
583  * @dev: DRM device
584  * @afbc_fb: afbc-specific framebuffer
585  * @mode_cmd: Metadata from the userspace framebuffer creation request
586  * @afbc_fb: afbc framebuffer
587  *
588  * This function can be used by drivers which support afbc to complete
589  * the preparation of struct drm_afbc_framebuffer. It must be called after
590  * allocating the said struct and calling drm_gem_fb_init_with_funcs().
591  * It is caller's responsibility to put afbc_fb->base.obj objects in case
592  * the call is unsuccessful.
593  *
594  * Returns:
595  * Zero on success or a negative error value on failure.
596  */
597 int drm_gem_fb_afbc_init(struct drm_device *dev,
598 			 const struct drm_mode_fb_cmd2 *mode_cmd,
599 			 struct drm_afbc_framebuffer *afbc_fb)
600 {
601 	const struct drm_format_info *info;
602 	struct drm_gem_object **objs;
603 	int ret;
604 
605 	objs = afbc_fb->base.obj;
606 	info = drm_get_format_info(dev, mode_cmd);
607 	if (!info)
608 		return -EINVAL;
609 
610 	ret = drm_gem_afbc_min_size(dev, mode_cmd, afbc_fb);
611 	if (ret < 0)
612 		return ret;
613 
614 	if (objs[0]->size < afbc_fb->afbc_size)
615 		return -EINVAL;
616 
617 	return 0;
618 }
619 EXPORT_SYMBOL_GPL(drm_gem_fb_afbc_init);
620