summaryrefslogtreecommitdiff
path: root/drivers/gpu/drm/exynos/exynos_drm_gem.c
blob: d88931d964d991fa6c4979063483ade28e75f8bd (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
612
613
614
615
616
617
618
619
620
621
622
623
624
625
626
627
628
629
630
631
632
633
634
635
636
637
638
639
640
641
642
643
644
645
646
647
648
649
650
651
652
653
654
655
656
657
658
659
660
661
662
663
664
665
666
667
668
669
670
671
672
673
674
675
676
677
678
679
680
681
682
683
684
685
686
687
688
689
690
691
692
693
694
695
696
697
698
699
700
701
702
703
704
705
706
707
708
709
710
711
712
713
714
715
716
717
718
719
720
721
722
723
724
725
726
727
728
729
730
731
732
733
734
735
736
737
738
739
740
741
742
743
744
745
746
747
748
749
750
751
752
753
754
755
756
757
758
759
760
/* exynos_drm_gem.c
 *
 * Copyright (c) 2011 Samsung Electronics Co., Ltd.
 * Author: Inki Dae <inki.dae@samsung.com>
 *
 * This program is free software; you can redistribute  it and/or modify it
 * under  the terms of  the GNU General  Public License as published by the
 * Free Software Foundation;  either version 2 of the  License, or (at your
 * option) any later version.
 */

#include <drm/drmP.h>

#include <linux/shmem_fs.h>
#include <drm/exynos_drm.h>

#include "exynos_drm_drv.h"
#include "exynos_drm_gem.h"
#include "exynos_drm_buf.h"

static unsigned int convert_to_vm_err_msg(int msg)
{
	unsigned int out_msg;

	switch (msg) {
	case 0:
	case -ERESTARTSYS:
	case -EINTR:
		out_msg = VM_FAULT_NOPAGE;
		break;

	case -ENOMEM:
		out_msg = VM_FAULT_OOM;
		break;

	default:
		out_msg = VM_FAULT_SIGBUS;
		break;
	}

	return out_msg;
}

static int check_gem_flags(unsigned int flags)
{
	if (flags & ~(EXYNOS_BO_MASK)) {
		DRM_ERROR("invalid flags.\n");
		return -EINVAL;
	}

	return 0;
}

static void update_vm_cache_attr(struct exynos_drm_gem_obj *obj,
					struct vm_area_struct *vma)
{
	DRM_DEBUG_KMS("flags = 0x%x\n", obj->flags);

	/* non-cachable as default. */
	if (obj->flags & EXYNOS_BO_CACHABLE)
		vma->vm_page_prot = vm_get_page_prot(vma->vm_flags);
	else if (obj->flags & EXYNOS_BO_WC)
		vma->vm_page_prot =
			pgprot_writecombine(vm_get_page_prot(vma->vm_flags));
	else
		vma->vm_page_prot =
			pgprot_noncached(vm_get_page_prot(vma->vm_flags));
}

static unsigned long roundup_gem_size(unsigned long size, unsigned int flags)
{
	/* TODO */

	return roundup(size, PAGE_SIZE);
}

static int exynos_drm_gem_map_buf(struct drm_gem_object *obj,
					struct vm_area_struct *vma,
					unsigned long f_vaddr,
					pgoff_t page_offset)
{
	struct exynos_drm_gem_obj *exynos_gem_obj = to_exynos_gem_obj(obj);
	struct exynos_drm_gem_buf *buf = exynos_gem_obj->buffer;
	struct scatterlist *sgl;
	unsigned long pfn;
	int i;

	if (!buf->sgt)
		return -EINTR;

	if (page_offset >= (buf->size >> PAGE_SHIFT)) {
		DRM_ERROR("invalid page offset\n");
		return -EINVAL;
	}

	sgl = buf->sgt->sgl;
	for_each_sg(buf->sgt->sgl, sgl, buf->sgt->nents, i) {
		if (page_offset < (sgl->length >> PAGE_SHIFT))
			break;
		page_offset -=	(sgl->length >> PAGE_SHIFT);
	}

	pfn = __phys_to_pfn(sg_phys(sgl)) + page_offset;

	return vm_insert_mixed(vma, f_vaddr, pfn);
}

static int exynos_drm_gem_handle_create(struct drm_gem_object *obj,
					struct drm_file *file_priv,
					unsigned int *handle)
{
	int ret;

	/*
	 * allocate a id of idr table where the obj is registered
	 * and handle has the id what user can see.
	 */
	ret = drm_gem_handle_create(file_priv, obj, handle);
	if (ret)
		return ret;

	DRM_DEBUG_KMS("gem handle = 0x%x\n", *handle);

	/* drop reference from allocate - handle holds it now. */
	drm_gem_object_unreference_unlocked(obj);

	return 0;
}

void exynos_drm_gem_destroy(struct exynos_drm_gem_obj *exynos_gem_obj)
{
	struct drm_gem_object *obj;
	struct exynos_drm_gem_buf *buf;

	obj = &exynos_gem_obj->base;
	buf = exynos_gem_obj->buffer;

	DRM_DEBUG_KMS("handle count = %d\n", atomic_read(&obj->handle_count));

	/*
	 * do not release memory region from exporter.
	 *
	 * the region will be released by exporter
	 * once dmabuf's refcount becomes 0.
	 */
	if (obj->import_attach)
		goto out;

	exynos_drm_free_buf(obj->dev, exynos_gem_obj->flags, buf);

out:
	exynos_drm_fini_buf(obj->dev, buf);
	exynos_gem_obj->buffer = NULL;

	if (obj->map_list.map)
		drm_gem_free_mmap_offset(obj);

	/* release file pointer to gem object. */
	drm_gem_object_release(obj);

	kfree(exynos_gem_obj);
	exynos_gem_obj = NULL;
}

unsigned long exynos_drm_gem_get_size(struct drm_device *dev,
						unsigned int gem_handle,
						struct drm_file *file_priv)
{
	struct exynos_drm_gem_obj *exynos_gem_obj;
	struct drm_gem_object *obj;

	obj = drm_gem_object_lookup(dev, file_priv, gem_handle);
	if (!obj) {
		DRM_ERROR("failed to lookup gem object.\n");
		return 0;
	}

	exynos_gem_obj = to_exynos_gem_obj(obj);

	drm_gem_object_unreference_unlocked(obj);

	return exynos_gem_obj->buffer->size;
}


struct exynos_drm_gem_obj *exynos_drm_gem_init(struct drm_device *dev,
						      unsigned long size)
{
	struct exynos_drm_gem_obj *exynos_gem_obj;
	struct drm_gem_object *obj;
	int ret;

	exynos_gem_obj = kzalloc(sizeof(*exynos_gem_obj), GFP_KERNEL);
	if (!exynos_gem_obj)
		return NULL;

	exynos_gem_obj->size = size;
	obj = &exynos_gem_obj->base;

	ret = drm_gem_object_init(dev, obj, size);
	if (ret < 0) {
		DRM_ERROR("failed to initialize gem object\n");
		kfree(exynos_gem_obj);
		return NULL;
	}

	DRM_DEBUG_KMS("created file object = 0x%x\n", (unsigned int)obj->filp);

	return exynos_gem_obj;
}

struct exynos_drm_gem_obj *exynos_drm_gem_create(struct drm_device *dev,
						unsigned int flags,
						unsigned long size)
{
	struct exynos_drm_gem_obj *exynos_gem_obj;
	struct exynos_drm_gem_buf *buf;
	int ret;

	if (!size) {
		DRM_ERROR("invalid size.\n");
		return ERR_PTR(-EINVAL);
	}

	size = roundup_gem_size(size, flags);

	ret = check_gem_flags(flags);
	if (ret)
		return ERR_PTR(ret);

	buf = exynos_drm_init_buf(dev, size);
	if (!buf)
		return ERR_PTR(-ENOMEM);

	exynos_gem_obj = exynos_drm_gem_init(dev, size);
	if (!exynos_gem_obj) {
		ret = -ENOMEM;
		goto err_fini_buf;
	}

	exynos_gem_obj->buffer = buf;

	/* set memory type and cache attribute from user side. */
	exynos_gem_obj->flags = flags;

	ret = exynos_drm_alloc_buf(dev, buf, flags);
	if (ret < 0) {
		drm_gem_object_release(&exynos_gem_obj->base);
		goto err_fini_buf;
	}

	return exynos_gem_obj;

err_fini_buf:
	exynos_drm_fini_buf(dev, buf);
	return ERR_PTR(ret);
}

int exynos_drm_gem_create_ioctl(struct drm_device *dev, void *data,
				struct drm_file *file_priv)
{
	struct drm_exynos_gem_create *args = data;
	struct exynos_drm_gem_obj *exynos_gem_obj;
	int ret;

	exynos_gem_obj = exynos_drm_gem_create(dev, args->flags, args->size);
	if (IS_ERR(exynos_gem_obj))
		return PTR_ERR(exynos_gem_obj);

	ret = exynos_drm_gem_handle_create(&exynos_gem_obj->base, file_priv,
			&args->handle);
	if (ret) {
		exynos_drm_gem_destroy(exynos_gem_obj);
		return ret;
	}

	return 0;
}

dma_addr_t *exynos_drm_gem_get_dma_addr(struct drm_device *dev,
					unsigned int gem_handle,
					struct drm_file *filp)
{
	struct exynos_drm_gem_obj *exynos_gem_obj;
	struct drm_gem_object *obj;

	obj = drm_gem_object_lookup(dev, filp, gem_handle);
	if (!obj) {
		DRM_ERROR("failed to lookup gem object.\n");
		return ERR_PTR(-EINVAL);
	}

	exynos_gem_obj = to_exynos_gem_obj(obj);

	return &exynos_gem_obj->buffer->dma_addr;
}

void exynos_drm_gem_put_dma_addr(struct drm_device *dev,
					unsigned int gem_handle,
					struct drm_file *filp)
{
	struct exynos_drm_gem_obj *exynos_gem_obj;
	struct drm_gem_object *obj;

	obj = drm_gem_object_lookup(dev, filp, gem_handle);
	if (!obj) {
		DRM_ERROR("failed to lookup gem object.\n");
		return;
	}

	exynos_gem_obj = to_exynos_gem_obj(obj);

	drm_gem_object_unreference_unlocked(obj);

	/*
	 * decrease obj->refcount one more time because we has already
	 * increased it at exynos_drm_gem_get_dma_addr().
	 */
	drm_gem_object_unreference_unlocked(obj);
}

void *exynos_drm_gem_get_dmabuf(struct drm_device *dev,
					unsigned int gem_handle,
					struct drm_file *filp)
{
	struct drm_gem_object *obj;

	obj = drm_gem_object_lookup(dev, filp, gem_handle);
	if (!obj) {
		DRM_ERROR("failed to lookup gem object.\n");
		return ERR_PTR(-EINVAL);
	}

	drm_gem_object_unreference_unlocked(obj);

	return obj->export_dma_buf;
}

int exynos_drm_gem_map_offset_ioctl(struct drm_device *dev, void *data,
				    struct drm_file *file_priv)
{
	struct drm_exynos_gem_map_off *args = data;

	DRM_DEBUG_KMS("handle = 0x%x, offset = 0x%lx\n",
			args->handle, (unsigned long)args->offset);

	if (!(dev->driver->driver_features & DRIVER_GEM)) {
		DRM_ERROR("does not support GEM.\n");
		return -ENODEV;
	}

	return exynos_drm_gem_dumb_map_offset(file_priv, dev, args->handle,
			&args->offset);
}

int exynos_drm_gem_mmap_buffer(struct file *filp,
				      struct vm_area_struct *vma)
{
	struct drm_gem_object *obj = filp->private_data;
	struct exynos_drm_gem_obj *exynos_gem_obj = to_exynos_gem_obj(obj);
	struct drm_device *drm_dev = obj->dev;
	struct exynos_drm_gem_buf *buffer;
	unsigned long vm_size;
	int ret;

	WARN_ON(!mutex_is_locked(&obj->dev->struct_mutex));

	vma->vm_flags |= VM_IO | VM_DONTEXPAND | VM_DONTDUMP;
	vma->vm_private_data = obj;
	vma->vm_ops = drm_dev->driver->gem_vm_ops;

	update_vm_cache_attr(exynos_gem_obj, vma);

	vm_size = vma->vm_end - vma->vm_start;

	/*
	 * a buffer contains information to physically continuous memory
	 * allocated by user request or at framebuffer creation.
	 */
	buffer = exynos_gem_obj->buffer;

	/* check if user-requested size is valid. */
	if (vm_size > buffer->size)
		return -EINVAL;

	ret = dma_mmap_attrs(drm_dev->dev, vma, buffer->pages,
				buffer->dma_addr, buffer->size,
				&buffer->dma_attrs);
	if (ret < 0) {
		DRM_ERROR("failed to mmap.\n");
		return ret;
	}

	/*
	 * take a reference to this mapping of the object. And this reference
	 * is unreferenced by the corresponding vm_close call.
	 */
	drm_gem_object_reference(obj);

	drm_vm_open_locked(drm_dev, vma);

	return 0;
}

int exynos_drm_gem_mmap_ioctl(struct drm_device *dev, void *data,
			      struct drm_file *file_priv)
{
	struct drm_exynos_file_private *exynos_file_priv;
	struct drm_exynos_gem_mmap *args = data;
	struct drm_gem_object *obj;
	struct file *anon_filp;
	unsigned int addr;

	if (!(dev->driver->driver_features & DRIVER_GEM)) {
		DRM_ERROR("does not support GEM.\n");
		return -ENODEV;
	}

	mutex_lock(&dev->struct_mutex);

	obj = drm_gem_object_lookup(dev, file_priv, args->handle);
	if (!obj) {
		DRM_ERROR("failed to lookup gem object.\n");
		mutex_unlock(&dev->struct_mutex);
		return -EINVAL;
	}

	exynos_file_priv = file_priv->driver_priv;
	anon_filp = exynos_file_priv->anon_filp;
	anon_filp->private_data = obj;

	addr = vm_mmap(anon_filp, 0, args->size, PROT_READ | PROT_WRITE,
			MAP_SHARED, 0);

	drm_gem_object_unreference(obj);

	if (IS_ERR((void *)addr)) {
		mutex_unlock(&dev->struct_mutex);
		return PTR_ERR((void *)addr);
	}

	mutex_unlock(&dev->struct_mutex);

	args->mapped = addr;

	DRM_DEBUG_KMS("mapped = 0x%lx\n", (unsigned long)args->mapped);

	return 0;
}

int exynos_drm_gem_get_ioctl(struct drm_device *dev, void *data,
				      struct drm_file *file_priv)
{	struct exynos_drm_gem_obj *exynos_gem_obj;
	struct drm_exynos_gem_info *args = data;
	struct drm_gem_object *obj;

	mutex_lock(&dev->struct_mutex);

	obj = drm_gem_object_lookup(dev, file_priv, args->handle);
	if (!obj) {
		DRM_ERROR("failed to lookup gem object.\n");
		mutex_unlock(&dev->struct_mutex);
		return -EINVAL;
	}

	exynos_gem_obj = to_exynos_gem_obj(obj);

	args->flags = exynos_gem_obj->flags;
	args->size = exynos_gem_obj->size;

	drm_gem_object_unreference(obj);
	mutex_unlock(&dev->struct_mutex);

	return 0;
}

struct vm_area_struct *exynos_gem_get_vma(struct vm_area_struct *vma)
{
	struct vm_area_struct *vma_copy;

	vma_copy = kmalloc(sizeof(*vma_copy), GFP_KERNEL);
	if (!vma_copy)
		return NULL;

	if (vma->vm_ops && vma->vm_ops->open)
		vma->vm_ops->open(vma);

	if (vma->vm_file)
		get_file(vma->vm_file);

	memcpy(vma_copy, vma, sizeof(*vma));

	vma_copy->vm_mm = NULL;
	vma_copy->vm_next = NULL;
	vma_copy->vm_prev = NULL;

	return vma_copy;
}

void exynos_gem_put_vma(struct vm_area_struct *vma)
{
	if (!vma)
		return;

	if (vma->vm_ops && vma->vm_ops->close)
		vma->vm_ops->close(vma);

	if (vma->vm_file)
		fput(vma->vm_file);

	kfree(vma);
}

int exynos_gem_get_pages_from_userptr(unsigned long start,
						unsigned int npages,
						struct page **pages,
						struct vm_area_struct *vma)
{
	int get_npages;

	/* the memory region mmaped with VM_PFNMAP. */
	if (vma_is_io(vma)) {
		unsigned int i;

		for (i = 0; i < npages; ++i, start += PAGE_SIZE) {
			unsigned long pfn;
			int ret = follow_pfn(vma, start, &pfn);
			if (ret)
				return ret;

			pages[i] = pfn_to_page(pfn);
		}

		if (i != npages) {
			DRM_ERROR("failed to get user_pages.\n");
			return -EINVAL;
		}

		return 0;
	}

	get_npages = get_user_pages(current, current->mm, start,
					npages, 1, 1, pages, NULL);
	get_npages = max(get_npages, 0);
	if (get_npages != npages) {
		DRM_ERROR("failed to get user_pages.\n");
		while (get_npages)
			put_page(pages[--get_npages]);
		return -EFAULT;
	}

	return 0;
}

void exynos_gem_put_pages_to_userptr(struct page **pages,
					unsigned int npages,
					struct vm_area_struct *vma)
{
	if (!vma_is_io(vma)) {
		unsigned int i;

		for (i = 0; i < npages; i++) {
			set_page_dirty_lock(pages[i]);

			/*
			 * undo the reference we took when populating
			 * the table.
			 */
			put_page(pages[i]);
		}
	}
}

int exynos_gem_map_sgt_with_dma(struct drm_device *drm_dev,
				struct sg_table *sgt,
				enum dma_data_direction dir)
{
	int nents;

	mutex_lock(&drm_dev->struct_mutex);

	nents = dma_map_sg(drm_dev->dev, sgt->sgl, sgt->nents, dir);
	if (!nents) {
		DRM_ERROR("failed to map sgl with dma.\n");
		mutex_unlock(&drm_dev->struct_mutex);
		return nents;
	}

	mutex_unlock(&drm_dev->struct_mutex);
	return 0;
}

void exynos_gem_unmap_sgt_from_dma(struct drm_device *drm_dev,
				struct sg_table *sgt,
				enum dma_data_direction dir)
{
	dma_unmap_sg(drm_dev->dev, sgt->sgl, sgt->nents, dir);
}

int exynos_drm_gem_init_object(struct drm_gem_object *obj)
{
	return 0;
}

void exynos_drm_gem_free_object(struct drm_gem_object *obj)
{
	struct exynos_drm_gem_obj *exynos_gem_obj;
	struct exynos_drm_gem_buf *buf;

	exynos_gem_obj = to_exynos_gem_obj(obj);
	buf = exynos_gem_obj->buffer;

	if (obj->import_attach)
		drm_prime_gem_destroy(obj, buf->sgt);

	exynos_drm_gem_destroy(to_exynos_gem_obj(obj));
}

int exynos_drm_gem_dumb_create(struct drm_file *file_priv,
			       struct drm_device *dev,
			       struct drm_mode_create_dumb *args)
{
	struct exynos_drm_gem_obj *exynos_gem_obj;
	int ret;

	/*
	 * alocate memory to be used for framebuffer.
	 * - this callback would be called by user application
	 *	with DRM_IOCTL_MODE_CREATE_DUMB command.
	 */

	args->pitch = args->width * ((args->bpp + 7) / 8);
	args->size = args->pitch * args->height;

	exynos_gem_obj = exynos_drm_gem_create(dev, EXYNOS_BO_CONTIG |
						EXYNOS_BO_WC, args->size);
	if (IS_ERR(exynos_gem_obj))
		return PTR_ERR(exynos_gem_obj);

	ret = exynos_drm_gem_handle_create(&exynos_gem_obj->base, file_priv,
			&args->handle);
	if (ret) {
		exynos_drm_gem_destroy(exynos_gem_obj);
		return ret;
	}

	return 0;
}

int exynos_drm_gem_dumb_map_offset(struct drm_file *file_priv,
				   struct drm_device *dev, uint32_t handle,
				   uint64_t *offset)
{
	struct drm_gem_object *obj;
	int ret = 0;

	mutex_lock(&dev->struct_mutex);

	/*
	 * get offset of memory allocated for drm framebuffer.
	 * - this callback would be called by user application
	 *	with DRM_IOCTL_MODE_MAP_DUMB command.
	 */

	obj = drm_gem_object_lookup(dev, file_priv, handle);
	if (!obj) {
		DRM_ERROR("failed to lookup gem object.\n");
		ret = -EINVAL;
		goto unlock;
	}

	if (!obj->map_list.map) {
		ret = drm_gem_create_mmap_offset(obj);
		if (ret)
			goto out;
	}

	*offset = (u64)obj->map_list.hash.key << PAGE_SHIFT;
	DRM_DEBUG_KMS("offset = 0x%lx\n", (unsigned long)*offset);

out:
	drm_gem_object_unreference(obj);
unlock:
	mutex_unlock(&dev->struct_mutex);
	return ret;
}

int exynos_drm_gem_dumb_destroy(struct drm_file *file_priv,
				struct drm_device *dev,
				unsigned int handle)
{
	int ret;

	/*
	 * obj->refcount and obj->handle_count are decreased and
	 * if both them are 0 then exynos_drm_gem_free_object()
	 * would be called by callback to release resources.
	 */
	ret = drm_gem_handle_delete(file_priv, handle);
	if (ret < 0) {
		DRM_ERROR("failed to delete drm_gem_handle.\n");
		return ret;
	}

	return 0;
}

int exynos_drm_gem_fault(struct vm_area_struct *vma, struct vm_fault *vmf)
{
	struct drm_gem_object *obj = vma->vm_private_data;
	struct drm_device *dev = obj->dev;
	unsigned long f_vaddr;
	pgoff_t page_offset;
	int ret;

	page_offset = ((unsigned long)vmf->virtual_address -
			vma->vm_start) >> PAGE_SHIFT;
	f_vaddr = (unsigned long)vmf->virtual_address;

	mutex_lock(&dev->struct_mutex);

	ret = exynos_drm_gem_map_buf(obj, vma, f_vaddr, page_offset);
	if (ret < 0)
		DRM_ERROR("failed to map a buffer with user.\n");

	mutex_unlock(&dev->struct_mutex);

	return convert_to_vm_err_msg(ret);
}

int exynos_drm_gem_mmap(struct file *filp, struct vm_area_struct *vma)
{
	struct exynos_drm_gem_obj *exynos_gem_obj;
	struct drm_gem_object *obj;
	int ret;

	/* set vm_area_struct. */
	ret = drm_gem_mmap(filp, vma);
	if (ret < 0) {
		DRM_ERROR("failed to mmap.\n");
		return ret;
	}

	obj = vma->vm_private_data;
	exynos_gem_obj = to_exynos_gem_obj(obj);

	ret = check_gem_flags(exynos_gem_obj->flags);
	if (ret) {
		drm_gem_vm_close(vma);
		drm_gem_free_mmap_offset(obj);
		return ret;
	}

	vma->vm_flags &= ~VM_PFNMAP;
	vma->vm_flags |= VM_MIXEDMAP;

	update_vm_cache_attr(exynos_gem_obj, vma);

	return ret;
}