aboutsummaryrefslogtreecommitdiffstats
path: root/drivers/gpu/drm/omapdrm/omap_gem_dmabuf.c
blob: 57af3d97be77a5d5f56de7a4a44fa3fd1755edaa (plain) (blame)
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
// SPDX-License-Identifier: GPL-2.0-only
/*
 * Copyright (C) 2011 Texas Instruments Incorporated - https://www.ti.com/
 * Author: Rob Clark <rob.clark@linaro.org>
 */

#include <linux/dma-buf.h>
#include <linux/highmem.h>

#include <drm/drm_prime.h>

#include "omap_drv.h"

MODULE_IMPORT_NS(DMA_BUF);

/* -----------------------------------------------------------------------------
 * DMABUF Export
 */

static struct sg_table *omap_gem_map_dma_buf(
		struct dma_buf_attachment *attachment,
		enum dma_data_direction dir)
{
	struct drm_gem_object *obj = attachment->dmabuf->priv;
	struct sg_table *sg;
	sg = omap_gem_get_sg(obj);
	if (IS_ERR(sg))
		return sg;

	/* this must be after omap_gem_pin() to ensure we have pages attached */
	omap_gem_dma_sync_buffer(obj, dir);

	return sg;
}

static void omap_gem_unmap_dma_buf(struct dma_buf_attachment *attachment,
		struct sg_table *sg, enum dma_data_direction dir)
{
	struct drm_gem_object *obj = attachment->dmabuf->priv;
	omap_gem_put_sg(obj, sg);
}

static int omap_gem_dmabuf_begin_cpu_access(struct dma_buf *buffer,
		enum dma_data_direction dir)
{
	struct drm_gem_object *obj = buffer->priv;
	struct page **pages;
	if (omap_gem_flags(obj) & OMAP_BO_TILED_MASK) {
		/* TODO we would need to pin at least part of the buffer to
		 * get de-tiled view.  For now just reject it.
		 */
		return -ENOMEM;
	}
	/* make sure we have the pages: */
	return omap_gem_get_pages(obj, &pages, true);
}

static int omap_gem_dmabuf_end_cpu_access(struct dma_buf *buffer,
					  enum dma_data_direction dir)
{
	struct drm_gem_object *obj = buffer->priv;
	omap_gem_put_pages(obj);
	return 0;
}

static int omap_gem_dmabuf_mmap(struct dma_buf *buffer,
		struct vm_area_struct *vma)
{
	struct drm_gem_object *obj = buffer->priv;
	int ret = 0;

	ret = drm_gem_mmap_obj(obj, omap_gem_mmap_size(obj), vma);
	if (ret < 0)
		return ret;

	return omap_gem_mmap_obj(obj, vma);
}

static const struct dma_buf_ops omap_dmabuf_ops = {
	.map_dma_buf = omap_gem_map_dma_buf,
	.unmap_dma_buf = omap_gem_unmap_dma_buf,
	.release = drm_gem_dmabuf_release,
	.begin_cpu_access = omap_gem_dmabuf_begin_cpu_access,
	.end_cpu_access = omap_gem_dmabuf_end_cpu_access,
	.mmap = omap_gem_dmabuf_mmap,
};

struct dma_buf *omap_gem_prime_export(struct drm_gem_object *obj, int flags)
{
	DEFINE_DMA_BUF_EXPORT_INFO(exp_info);

	exp_info.ops = &omap_dmabuf_ops;
	exp_info.size = omap_gem_mmap_size(obj);
	exp_info.flags = flags;
	exp_info.priv = obj;

	return drm_gem_dmabuf_export(obj->dev, &exp_info);
}

/* -----------------------------------------------------------------------------
 * DMABUF Import
 */

struct drm_gem_object *omap_gem_prime_import(struct drm_device *dev,
					     struct dma_buf *dma_buf)
{
	struct dma_buf_attachment *attach;
	struct drm_gem_object *obj;
	struct sg_table *sgt;
	int ret;

	if (dma_buf->ops == &omap_dmabuf_ops) {
		obj = dma_buf->priv;
		if (obj->dev == dev) {
			/*
			 * Importing dmabuf exported from out own gem increases
			 * refcount on gem itself instead of f_count of dmabuf.
			 */
			drm_gem_object_get(obj);
			return obj;
		}
	}

	attach = dma_buf_attach(dma_buf, dev->dev);
	if (IS_ERR(attach))
		return ERR_CAST(attach);

	get_dma_buf(dma_buf);

	sgt = dma_buf_map_attachment(attach, DMA_TO_DEVICE);
	if (IS_ERR(sgt)) {
		ret = PTR_ERR(sgt);
		goto fail_detach;
	}

	obj = omap_gem_new_dmabuf(dev, dma_buf->size, sgt);
	if (IS_ERR(obj)) {
		ret = PTR_ERR(obj);
		goto fail_unmap;
	}

	obj->import_attach = attach;

	return obj;

fail_unmap:
	dma_buf_unmap_attachment(attach, sgt, DMA_TO_DEVICE);
fail_detach:
	dma_buf_detach(dma_buf, attach);
	dma_buf_put(dma_buf);

	return ERR_PTR(ret);
}