aboutsummaryrefslogtreecommitdiffstats
path: root/drivers/gpu/drm/exynos/exynos_drm_dmabuf.c
blob: ae13febe0eaa64e821adf2f5db306e5ebdd07186 (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
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
/* exynos_drm_dmabuf.c
 *
 * Copyright (c) 2012 Samsung Electronics Co., Ltd.
 * Author: Inki Dae <inki.dae@samsung.com>
 *
 * Permission is hereby granted, free of charge, to any person obtaining a
 * copy of this software and associated documentation files (the "Software"),
 * to deal in the Software without restriction, including without limitation
 * the rights to use, copy, modify, merge, publish, distribute, sublicense,
 * and/or sell copies of the Software, and to permit persons to whom the
 * Software is furnished to do so, subject to the following conditions:
 *
 * The above copyright notice and this permission notice (including the next
 * paragraph) shall be included in all copies or substantial portions of the
 * Software.
 *
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL
 * VA LINUX SYSTEMS AND/OR ITS SUPPLIERS BE LIABLE FOR ANY CLAIM, DAMAGES OR
 * OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE,
 * ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR
 * OTHER DEALINGS IN THE SOFTWARE.
 */

#include "drmP.h"
#include "drm.h"
#include "exynos_drm.h"
#include "exynos_drm_drv.h"
#include "exynos_drm_gem.h"

#include <linux/dma-buf.h>

static struct sg_table *exynos_pages_to_sg(struct page **pages, int nr_pages,
		unsigned int page_size)
{
	struct sg_table *sgt = NULL;
	struct scatterlist *sgl;
	int i, ret;

	sgt = kzalloc(sizeof(*sgt), GFP_KERNEL);
	if (!sgt)
		goto out;

	ret = sg_alloc_table(sgt, nr_pages, GFP_KERNEL);
	if (ret)
		goto err_free_sgt;

	if (page_size < PAGE_SIZE)
		page_size = PAGE_SIZE;

	for_each_sg(sgt->sgl, sgl, nr_pages, i)
		sg_set_page(sgl, pages[i], page_size, 0);

	return sgt;

err_free_sgt:
	kfree(sgt);
	sgt = NULL;
out:
	return NULL;
}

static struct sg_table *
		exynos_gem_map_dma_buf(struct dma_buf_attachment *attach,
					enum dma_data_direction dir)
{
	struct exynos_drm_gem_obj *gem_obj = attach->dmabuf->priv;
	struct drm_device *dev = gem_obj->base.dev;
	struct exynos_drm_gem_buf *buf;
	struct sg_table *sgt = NULL;
	unsigned int npages;
	int nents;

	DRM_DEBUG_PRIME("%s\n", __FILE__);

	mutex_lock(&dev->struct_mutex);

	buf = gem_obj->buffer;

	/* there should always be pages allocated. */
	if (!buf->pages) {
		DRM_ERROR("pages is null.\n");
		goto err_unlock;
	}

	npages = buf->size / buf->page_size;

	sgt = exynos_pages_to_sg(buf->pages, npages, buf->page_size);
	if (!sgt) {
		DRM_DEBUG_PRIME("exynos_pages_to_sg returned NULL!\n");
		goto err_unlock;
	}
	nents = dma_map_sg(attach->dev, sgt->sgl, sgt->nents, dir);

	DRM_DEBUG_PRIME("npages = %d buffer size = 0x%lx page_size = 0x%lx\n",
			npages, buf->size, buf->page_size);

err_unlock:
	mutex_unlock(&dev->struct_mutex);
	return sgt;
}

static void exynos_gem_unmap_dma_buf(struct dma_buf_attachment *attach,
						struct sg_table *sgt,
						enum dma_data_direction dir)
{
	dma_unmap_sg(attach->dev, sgt->sgl, sgt->nents, dir);
	sg_free_table(sgt);
	kfree(sgt);
	sgt = NULL;
}

static void exynos_dmabuf_release(struct dma_buf *dmabuf)
{
	struct exynos_drm_gem_obj *exynos_gem_obj = dmabuf->priv;

	DRM_DEBUG_PRIME("%s\n", __FILE__);

	/*
	 * exynos_dmabuf_release() call means that file object's
	 * f_count is 0 and it calls drm_gem_object_handle_unreference()
	 * to drop the references that these values had been increased
	 * at drm_prime_handle_to_fd()
	 */
	if (exynos_gem_obj->base.export_dma_buf == dmabuf) {
		exynos_gem_obj->base.export_dma_buf = NULL;

		/*
		 * drop this gem object refcount to release allocated buffer
		 * and resources.
		 */
		drm_gem_object_unreference_unlocked(&exynos_gem_obj->base);
	}
}

static void *exynos_gem_dmabuf_kmap_atomic(struct dma_buf *dma_buf,
						unsigned long page_num)
{
	/* TODO */

	return NULL;
}

static void exynos_gem_dmabuf_kunmap_atomic(struct dma_buf *dma_buf,
						unsigned long page_num,
						void *addr)
{
	/* TODO */
}

static void *exynos_gem_dmabuf_kmap(struct dma_buf *dma_buf,
					unsigned long page_num)
{
	/* TODO */

	return NULL;
}

static void exynos_gem_dmabuf_kunmap(struct dma_buf *dma_buf,
					unsigned long page_num, void *addr)
{
	/* TODO */
}

static int exynos_gem_dmabuf_mmap(struct dma_buf *dma_buf,
	struct vm_area_struct *vma)
{
	return -ENOTTY;
}

static struct dma_buf_ops exynos_dmabuf_ops = {
	.map_dma_buf		= exynos_gem_map_dma_buf,
	.unmap_dma_buf		= exynos_gem_unmap_dma_buf,
	.kmap			= exynos_gem_dmabuf_kmap,
	.kmap_atomic		= exynos_gem_dmabuf_kmap_atomic,
	.kunmap			= exynos_gem_dmabuf_kunmap,
	.kunmap_atomic		= exynos_gem_dmabuf_kunmap_atomic,
	.mmap			= exynos_gem_dmabuf_mmap,
	.release		= exynos_dmabuf_release,
};

struct dma_buf *exynos_dmabuf_prime_export(struct drm_device *drm_dev,
				struct drm_gem_object *obj, int flags)
{
	struct exynos_drm_gem_obj *exynos_gem_obj = to_exynos_gem_obj(obj);

	return dma_buf_export(exynos_gem_obj, &exynos_dmabuf_ops,
				exynos_gem_obj->base.size, 0600);
}

struct drm_gem_object *exynos_dmabuf_prime_import(struct drm_device *drm_dev,
				struct dma_buf *dma_buf)
{
	struct dma_buf_attachment *attach;
	struct sg_table *sgt;
	struct scatterlist *sgl;
	struct exynos_drm_gem_obj *exynos_gem_obj;
	struct exynos_drm_gem_buf *buffer;
	struct page *page;
	int ret;

	DRM_DEBUG_PRIME("%s\n", __FILE__);

	/* is this one of own objects? */
	if (dma_buf->ops == &exynos_dmabuf_ops) {
		struct drm_gem_object *obj;

		exynos_gem_obj = dma_buf->priv;
		obj = &exynos_gem_obj->base;

		/* is it from our device? */
		if (obj->dev == drm_dev) {
			drm_gem_object_reference(obj);
			return obj;
		}
	}

	attach = dma_buf_attach(dma_buf, drm_dev->dev);
	if (IS_ERR(attach))
		return ERR_PTR(-EINVAL);


	sgt = dma_buf_map_attachment(attach, DMA_BIDIRECTIONAL);
	if (IS_ERR_OR_NULL(sgt)) {
		ret = PTR_ERR(sgt);
		goto err_buf_detach;
	}

	buffer = kzalloc(sizeof(*buffer), GFP_KERNEL);
	if (!buffer) {
		DRM_ERROR("failed to allocate exynos_drm_gem_buf.\n");
		ret = -ENOMEM;
		goto err_unmap_attach;
	}

	buffer->pages = kzalloc(sizeof(*page) * sgt->nents, GFP_KERNEL);
	if (!buffer->pages) {
		DRM_ERROR("failed to allocate pages.\n");
		ret = -ENOMEM;
		goto err_free_buffer;
	}

	exynos_gem_obj = exynos_drm_gem_init(drm_dev, dma_buf->size);
	if (!exynos_gem_obj) {
		ret = -ENOMEM;
		goto err_free_pages;
	}

	sgl = sgt->sgl;

	if (sgt->nents == 1) {
		buffer->dma_addr = sg_dma_address(sgt->sgl);
		buffer->size = sg_dma_len(sgt->sgl);

		/* always physically continuous memory if sgt->nents is 1. */
		exynos_gem_obj->flags |= EXYNOS_BO_CONTIG;
	} else {
		unsigned int i = 0;

		buffer->dma_addr = sg_dma_address(sgl);
		while (i < sgt->nents) {
			buffer->pages[i] = sg_page(sgl);
			buffer->size += sg_dma_len(sgl);
			sgl = sg_next(sgl);
			i++;
		}

		exynos_gem_obj->flags |= EXYNOS_BO_NONCONTIG;
	}

	exynos_gem_obj->buffer = buffer;
	buffer->sgt = sgt;
	exynos_gem_obj->base.import_attach = attach;

	DRM_DEBUG_PRIME("dma_addr = 0x%x, size = 0x%lx\n", buffer->dma_addr,
								buffer->size);

	return &exynos_gem_obj->base;

err_free_pages:
	kfree(buffer->pages);
	buffer->pages = NULL;
err_free_buffer:
	kfree(buffer);
	buffer = NULL;
err_unmap_attach:
	dma_buf_unmap_attachment(attach, sgt, DMA_BIDIRECTIONAL);
err_buf_detach:
	dma_buf_detach(dma_buf, attach);
	return ERR_PTR(ret);
}

MODULE_AUTHOR("Inki Dae <inki.dae@samsung.com>");
MODULE_DESCRIPTION("Samsung SoC DRM DMABUF Module");
MODULE_LICENSE("GPL");