1 /*
2 * Copyright (C) 2011 Texas Instruments Incorporated - http://www.ti.com/
3 * Author: Rob Clark <rob.clark@linaro.org>
4 *
5 * This program is free software; you can redistribute it and/or modify it
6 * under the terms of the GNU General Public License version 2 as published by
7 * the Free Software Foundation.
8 *
9 * This program is distributed in the hope that it will be useful, but WITHOUT
10 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
11 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for
12 * more details.
13 *
14 * You should have received a copy of the GNU General Public License along with
15 * this program. If not, see <http://www.gnu.org/licenses/>.
16 */
17
18 #include <linux/dma-buf.h>
19
20 #include "omap_drv.h"
21
22 /* -----------------------------------------------------------------------------
23 * DMABUF Export
24 */
25
omap_gem_map_dma_buf(struct dma_buf_attachment * attachment,enum dma_data_direction dir)26 static struct sg_table *omap_gem_map_dma_buf(
27 struct dma_buf_attachment *attachment,
28 enum dma_data_direction dir)
29 {
30 struct drm_gem_object *obj = attachment->dmabuf->priv;
31 struct sg_table *sg;
32 dma_addr_t dma_addr;
33 int ret;
34
35 sg = kzalloc(sizeof(*sg), GFP_KERNEL);
36 if (!sg)
37 return ERR_PTR(-ENOMEM);
38
39 /* camera, etc, need physically contiguous.. but we need a
40 * better way to know this..
41 */
42 ret = omap_gem_pin(obj, &dma_addr);
43 if (ret)
44 goto out;
45
46 ret = sg_alloc_table(sg, 1, GFP_KERNEL);
47 if (ret)
48 goto out;
49
50 sg_init_table(sg->sgl, 1);
51 sg_dma_len(sg->sgl) = obj->size;
52 sg_set_page(sg->sgl, pfn_to_page(PFN_DOWN(dma_addr)), obj->size, 0);
53 sg_dma_address(sg->sgl) = dma_addr;
54
55 /* this must be after omap_gem_pin() to ensure we have pages attached */
56 omap_gem_dma_sync_buffer(obj, dir);
57
58 return sg;
59 out:
60 kfree(sg);
61 return ERR_PTR(ret);
62 }
63
omap_gem_unmap_dma_buf(struct dma_buf_attachment * attachment,struct sg_table * sg,enum dma_data_direction dir)64 static void omap_gem_unmap_dma_buf(struct dma_buf_attachment *attachment,
65 struct sg_table *sg, enum dma_data_direction dir)
66 {
67 struct drm_gem_object *obj = attachment->dmabuf->priv;
68 omap_gem_unpin(obj);
69 sg_free_table(sg);
70 kfree(sg);
71 }
72
omap_gem_dmabuf_begin_cpu_access(struct dma_buf * buffer,enum dma_data_direction dir)73 static int omap_gem_dmabuf_begin_cpu_access(struct dma_buf *buffer,
74 enum dma_data_direction dir)
75 {
76 struct drm_gem_object *obj = buffer->priv;
77 struct page **pages;
78 if (omap_gem_flags(obj) & OMAP_BO_TILED) {
79 /* TODO we would need to pin at least part of the buffer to
80 * get de-tiled view. For now just reject it.
81 */
82 return -ENOMEM;
83 }
84 /* make sure we have the pages: */
85 return omap_gem_get_pages(obj, &pages, true);
86 }
87
omap_gem_dmabuf_end_cpu_access(struct dma_buf * buffer,enum dma_data_direction dir)88 static int omap_gem_dmabuf_end_cpu_access(struct dma_buf *buffer,
89 enum dma_data_direction dir)
90 {
91 struct drm_gem_object *obj = buffer->priv;
92 omap_gem_put_pages(obj);
93 return 0;
94 }
95
omap_gem_dmabuf_kmap(struct dma_buf * buffer,unsigned long page_num)96 static void *omap_gem_dmabuf_kmap(struct dma_buf *buffer,
97 unsigned long page_num)
98 {
99 struct drm_gem_object *obj = buffer->priv;
100 struct page **pages;
101 omap_gem_get_pages(obj, &pages, false);
102 omap_gem_cpu_sync_page(obj, page_num);
103 return kmap(pages[page_num]);
104 }
105
omap_gem_dmabuf_kunmap(struct dma_buf * buffer,unsigned long page_num,void * addr)106 static void omap_gem_dmabuf_kunmap(struct dma_buf *buffer,
107 unsigned long page_num, void *addr)
108 {
109 struct drm_gem_object *obj = buffer->priv;
110 struct page **pages;
111 omap_gem_get_pages(obj, &pages, false);
112 kunmap(pages[page_num]);
113 }
114
omap_gem_dmabuf_mmap(struct dma_buf * buffer,struct vm_area_struct * vma)115 static int omap_gem_dmabuf_mmap(struct dma_buf *buffer,
116 struct vm_area_struct *vma)
117 {
118 struct drm_gem_object *obj = buffer->priv;
119 int ret = 0;
120
121 ret = drm_gem_mmap_obj(obj, omap_gem_mmap_size(obj), vma);
122 if (ret < 0)
123 return ret;
124
125 return omap_gem_mmap_obj(obj, vma);
126 }
127
128 static const struct dma_buf_ops omap_dmabuf_ops = {
129 .map_dma_buf = omap_gem_map_dma_buf,
130 .unmap_dma_buf = omap_gem_unmap_dma_buf,
131 .release = drm_gem_dmabuf_release,
132 .begin_cpu_access = omap_gem_dmabuf_begin_cpu_access,
133 .end_cpu_access = omap_gem_dmabuf_end_cpu_access,
134 .map = omap_gem_dmabuf_kmap,
135 .unmap = omap_gem_dmabuf_kunmap,
136 .mmap = omap_gem_dmabuf_mmap,
137 };
138
omap_gem_prime_export(struct drm_device * dev,struct drm_gem_object * obj,int flags)139 struct dma_buf *omap_gem_prime_export(struct drm_device *dev,
140 struct drm_gem_object *obj, int flags)
141 {
142 DEFINE_DMA_BUF_EXPORT_INFO(exp_info);
143
144 exp_info.ops = &omap_dmabuf_ops;
145 exp_info.size = obj->size;
146 exp_info.flags = flags;
147 exp_info.priv = obj;
148
149 return drm_gem_dmabuf_export(dev, &exp_info);
150 }
151
152 /* -----------------------------------------------------------------------------
153 * DMABUF Import
154 */
155
omap_gem_prime_import(struct drm_device * dev,struct dma_buf * dma_buf)156 struct drm_gem_object *omap_gem_prime_import(struct drm_device *dev,
157 struct dma_buf *dma_buf)
158 {
159 struct dma_buf_attachment *attach;
160 struct drm_gem_object *obj;
161 struct sg_table *sgt;
162 int ret;
163
164 if (dma_buf->ops == &omap_dmabuf_ops) {
165 obj = dma_buf->priv;
166 if (obj->dev == dev) {
167 /*
168 * Importing dmabuf exported from out own gem increases
169 * refcount on gem itself instead of f_count of dmabuf.
170 */
171 drm_gem_object_reference(obj);
172 return obj;
173 }
174 }
175
176 attach = dma_buf_attach(dma_buf, dev->dev);
177 if (IS_ERR(attach))
178 return ERR_CAST(attach);
179
180 get_dma_buf(dma_buf);
181
182 sgt = dma_buf_map_attachment(attach, DMA_TO_DEVICE);
183 if (IS_ERR(sgt)) {
184 ret = PTR_ERR(sgt);
185 goto fail_detach;
186 }
187
188 obj = omap_gem_new_dmabuf(dev, dma_buf->size, sgt);
189 if (IS_ERR(obj)) {
190 ret = PTR_ERR(obj);
191 goto fail_unmap;
192 }
193
194 obj->import_attach = attach;
195
196 return obj;
197
198 fail_unmap:
199 dma_buf_unmap_attachment(attach, sgt, DMA_TO_DEVICE);
200 fail_detach:
201 dma_buf_detach(dma_buf, attach);
202 dma_buf_put(dma_buf);
203
204 return ERR_PTR(ret);
205 }
206
