i915: add dmabuf/prime buffer sharing support.
[deliverable/linux.git] / drivers / gpu / drm / i915 / i915_gem_dmabuf.c
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1/*
2 * Copyright 2012 Red Hat Inc
3 *
4 * Permission is hereby granted, free of charge, to any person obtaining a
5 * copy of this software and associated documentation files (the "Software"),
6 * to deal in the Software without restriction, including without limitation
7 * the rights to use, copy, modify, merge, publish, distribute, sublicense,
8 * and/or sell copies of the Software, and to permit persons to whom the
9 * Software is furnished to do so, subject to the following conditions:
10 *
11 * The above copyright notice and this permission notice (including the next
12 * paragraph) shall be included in all copies or substantial portions of the
13 * Software.
14 *
15 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
16 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
17 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
18 * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
19 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
20 * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
21 * DEALINGS IN THE SOFTWARE.
22 *
23 * Authors:
24 * Dave Airlie <airlied@redhat.com>
25 */
26#include "drmP.h"
27#include "i915_drv.h"
28#include <linux/dma-buf.h>
29
30struct sg_table *i915_gem_map_dma_buf(struct dma_buf_attachment *attachment,
31 enum dma_data_direction dir)
32{
33 struct drm_i915_gem_object *obj = attachment->dmabuf->priv;
34 struct drm_device *dev = obj->base.dev;
35 int npages = obj->base.size / PAGE_SIZE;
36 struct sg_table *sg = NULL;
37 int ret;
38 int nents;
39
40 ret = i915_mutex_lock_interruptible(dev);
41 if (ret)
42 return ERR_PTR(ret);
43
44 if (!obj->pages) {
45 ret = i915_gem_object_get_pages_gtt(obj, __GFP_NORETRY | __GFP_NOWARN);
46 if (ret)
47 goto out;
48 }
49
50 /* link the pages into an SG then map the sg */
51 sg = drm_prime_pages_to_sg(obj->pages, npages);
52 nents = dma_map_sg(attachment->dev, sg->sgl, sg->nents, dir);
53out:
54 mutex_unlock(&dev->struct_mutex);
55 return sg;
56}
57
58void i915_gem_unmap_dma_buf(struct dma_buf_attachment *attachment,
59 struct sg_table *sg, enum dma_data_direction dir)
60{
61 dma_unmap_sg(attachment->dev, sg->sgl, sg->nents, dir);
62 sg_free_table(sg);
63 kfree(sg);
64}
65
66void i915_gem_dmabuf_release(struct dma_buf *dma_buf)
67{
68 struct drm_i915_gem_object *obj = dma_buf->priv;
69
70 if (obj->base.export_dma_buf == dma_buf) {
71 /* drop the reference on the export fd holds */
72 obj->base.export_dma_buf = NULL;
73 drm_gem_object_unreference_unlocked(&obj->base);
74 }
75}
76
77static void *i915_gem_dmabuf_kmap_atomic(struct dma_buf *dma_buf, unsigned long page_num)
78{
79 return NULL;
80}
81
82static void i915_gem_dmabuf_kunmap_atomic(struct dma_buf *dma_buf, unsigned long page_num, void *addr)
83{
84
85}
86static void *i915_gem_dmabuf_kmap(struct dma_buf *dma_buf, unsigned long page_num)
87{
88 return NULL;
89}
90
91static void i915_gem_dmabuf_kunmap(struct dma_buf *dma_buf, unsigned long page_num, void *addr)
92{
93
94}
95
96struct dma_buf_ops i915_dmabuf_ops = {
97 .map_dma_buf = i915_gem_map_dma_buf,
98 .unmap_dma_buf = i915_gem_unmap_dma_buf,
99 .release = i915_gem_dmabuf_release,
100 .kmap = i915_gem_dmabuf_kmap,
101 .kmap_atomic = i915_gem_dmabuf_kmap_atomic,
102 .kunmap = i915_gem_dmabuf_kunmap,
103 .kunmap_atomic = i915_gem_dmabuf_kunmap_atomic,
104};
105
106struct dma_buf *i915_gem_prime_export(struct drm_device *dev,
107 struct drm_gem_object *gem_obj, int flags)
108{
109 struct drm_i915_gem_object *obj = to_intel_bo(gem_obj);
110
111 return dma_buf_export(obj, &i915_dmabuf_ops,
112 obj->base.size, 0600);
113}
114
115struct drm_gem_object *i915_gem_prime_import(struct drm_device *dev,
116 struct dma_buf *dma_buf)
117{
118 struct dma_buf_attachment *attach;
119 struct sg_table *sg;
120 struct drm_i915_gem_object *obj;
121 int npages;
122 int size;
123 int ret;
124
125 /* is this one of own objects? */
126 if (dma_buf->ops == &i915_dmabuf_ops) {
127 obj = dma_buf->priv;
128 /* is it from our device? */
129 if (obj->base.dev == dev) {
130 drm_gem_object_reference(&obj->base);
131 return &obj->base;
132 }
133 }
134
135 /* need to attach */
136 attach = dma_buf_attach(dma_buf, dev->dev);
137 if (IS_ERR(attach))
138 return ERR_CAST(attach);
139
140 sg = dma_buf_map_attachment(attach, DMA_BIDIRECTIONAL);
141 if (IS_ERR(sg)) {
142 ret = PTR_ERR(sg);
143 goto fail_detach;
144 }
145
146 size = dma_buf->size;
147 npages = size / PAGE_SIZE;
148
149 obj = kzalloc(sizeof(*obj), GFP_KERNEL);
150 if (obj == NULL) {
151 ret = -ENOMEM;
152 goto fail_unmap;
153 }
154
155 ret = drm_gem_private_object_init(dev, &obj->base, size);
156 if (ret) {
157 kfree(obj);
158 goto fail_unmap;
159 }
160
161 obj->sg_table = sg;
162 obj->base.import_attach = attach;
163
164 return &obj->base;
165
166fail_unmap:
167 dma_buf_unmap_attachment(attach, sg, DMA_BIDIRECTIONAL);
168fail_detach:
169 dma_buf_detach(dma_buf, attach);
170 return ERR_PTR(ret);
171}
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