1 /*
2 * udl_dmabuf.c
3 *
4 * Copyright (c) 2014 The Chromium OS Authors
5 *
6 * This program is free software; you can redistribute it and/or modify it
7 * under the terms of the GNU General Public License as published by the
8 * Free Software Foundation; either version 2 of the License, or (at your
9 * option) any later version.
10 *
11 * This program is distributed in the hope that it will be useful,
12 * but WITHOUT ANY WARRANTY; without even the implied warranty of
13 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
14 * GNU General Public License for more details.
15 *
16 * You should have received a copy of the GNU General Public License
17 * along with this program. If not, see <http://www.gnu.org/licenses/>.
18 */
19
20 #include <drm/drmP.h>
21 #include "udl_drv.h"
22 #include <linux/shmem_fs.h>
23 #include <linux/dma-buf.h>
24
25 struct udl_drm_dmabuf_attachment {
26 struct sg_table sgt;
27 enum dma_data_direction dir;
28 bool is_mapped;
29 };
30
udl_attach_dma_buf(struct dma_buf * dmabuf,struct device * dev,struct dma_buf_attachment * attach)31 static int udl_attach_dma_buf(struct dma_buf *dmabuf,
32 struct device *dev,
33 struct dma_buf_attachment *attach)
34 {
35 struct udl_drm_dmabuf_attachment *udl_attach;
36
37 DRM_DEBUG_PRIME("[DEV:%s] size:%zd\n", dev_name(attach->dev),
38 attach->dmabuf->size);
39
40 udl_attach = kzalloc(sizeof(*udl_attach), GFP_KERNEL);
41 if (!udl_attach)
42 return -ENOMEM;
43
44 udl_attach->dir = DMA_NONE;
45 attach->priv = udl_attach;
46
47 return 0;
48 }
49
udl_detach_dma_buf(struct dma_buf * dmabuf,struct dma_buf_attachment * attach)50 static void udl_detach_dma_buf(struct dma_buf *dmabuf,
51 struct dma_buf_attachment *attach)
52 {
53 struct udl_drm_dmabuf_attachment *udl_attach = attach->priv;
54 struct sg_table *sgt;
55
56 if (!udl_attach)
57 return;
58
59 DRM_DEBUG_PRIME("[DEV:%s] size:%zd\n", dev_name(attach->dev),
60 attach->dmabuf->size);
61
62 sgt = &udl_attach->sgt;
63
64 if (udl_attach->dir != DMA_NONE)
65 dma_unmap_sg(attach->dev, sgt->sgl, sgt->nents,
66 udl_attach->dir);
67
68 sg_free_table(sgt);
69 kfree(udl_attach);
70 attach->priv = NULL;
71 }
72
udl_map_dma_buf(struct dma_buf_attachment * attach,enum dma_data_direction dir)73 static struct sg_table *udl_map_dma_buf(struct dma_buf_attachment *attach,
74 enum dma_data_direction dir)
75 {
76 struct udl_drm_dmabuf_attachment *udl_attach = attach->priv;
77 struct udl_gem_object *obj = to_udl_bo(attach->dmabuf->priv);
78 struct drm_device *dev = obj->base.dev;
79 struct scatterlist *rd, *wr;
80 struct sg_table *sgt = NULL;
81 unsigned int i;
82 int page_count;
83 int nents, ret;
84
85 DRM_DEBUG_PRIME("[DEV:%s] size:%zd dir=%d\n", dev_name(attach->dev),
86 attach->dmabuf->size, dir);
87
88 /* just return current sgt if already requested. */
89 if (udl_attach->dir == dir && udl_attach->is_mapped)
90 return &udl_attach->sgt;
91
92 if (!obj->pages) {
93 ret = udl_gem_get_pages(obj);
94 if (ret) {
95 DRM_ERROR("failed to map pages.\n");
96 return ERR_PTR(ret);
97 }
98 }
99
100 page_count = obj->base.size / PAGE_SIZE;
101 obj->sg = drm_prime_pages_to_sg(obj->pages, page_count);
102 if (IS_ERR(obj->sg)) {
103 DRM_ERROR("failed to allocate sgt.\n");
104 return ERR_CAST(obj->sg);
105 }
106
107 sgt = &udl_attach->sgt;
108
109 ret = sg_alloc_table(sgt, obj->sg->orig_nents, GFP_KERNEL);
110 if (ret) {
111 DRM_ERROR("failed to alloc sgt.\n");
112 return ERR_PTR(-ENOMEM);
113 }
114
115 mutex_lock(&dev->struct_mutex);
116
117 rd = obj->sg->sgl;
118 wr = sgt->sgl;
119 for (i = 0; i < sgt->orig_nents; ++i) {
120 sg_set_page(wr, sg_page(rd), rd->length, rd->offset);
121 rd = sg_next(rd);
122 wr = sg_next(wr);
123 }
124
125 if (dir != DMA_NONE) {
126 nents = dma_map_sg(attach->dev, sgt->sgl, sgt->orig_nents, dir);
127 if (!nents) {
128 DRM_ERROR("failed to map sgl with iommu.\n");
129 sg_free_table(sgt);
130 sgt = ERR_PTR(-EIO);
131 goto err_unlock;
132 }
133 }
134
135 udl_attach->is_mapped = true;
136 udl_attach->dir = dir;
137 attach->priv = udl_attach;
138
139 err_unlock:
140 mutex_unlock(&dev->struct_mutex);
141 return sgt;
142 }
143
udl_unmap_dma_buf(struct dma_buf_attachment * attach,struct sg_table * sgt,enum dma_data_direction dir)144 static void udl_unmap_dma_buf(struct dma_buf_attachment *attach,
145 struct sg_table *sgt,
146 enum dma_data_direction dir)
147 {
148 /* Nothing to do. */
149 DRM_DEBUG_PRIME("[DEV:%s] size:%zd dir:%d\n", dev_name(attach->dev),
150 attach->dmabuf->size, dir);
151 }
152
udl_dmabuf_kmap(struct dma_buf * dma_buf,unsigned long page_num)153 static void *udl_dmabuf_kmap(struct dma_buf *dma_buf, unsigned long page_num)
154 {
155 /* TODO */
156
157 return NULL;
158 }
159
udl_dmabuf_kmap_atomic(struct dma_buf * dma_buf,unsigned long page_num)160 static void *udl_dmabuf_kmap_atomic(struct dma_buf *dma_buf,
161 unsigned long page_num)
162 {
163 /* TODO */
164
165 return NULL;
166 }
167
udl_dmabuf_kunmap(struct dma_buf * dma_buf,unsigned long page_num,void * addr)168 static void udl_dmabuf_kunmap(struct dma_buf *dma_buf,
169 unsigned long page_num, void *addr)
170 {
171 /* TODO */
172 }
173
udl_dmabuf_kunmap_atomic(struct dma_buf * dma_buf,unsigned long page_num,void * addr)174 static void udl_dmabuf_kunmap_atomic(struct dma_buf *dma_buf,
175 unsigned long page_num,
176 void *addr)
177 {
178 /* TODO */
179 }
180
udl_dmabuf_mmap(struct dma_buf * dma_buf,struct vm_area_struct * vma)181 static int udl_dmabuf_mmap(struct dma_buf *dma_buf,
182 struct vm_area_struct *vma)
183 {
184 /* TODO */
185
186 return -EINVAL;
187 }
188
189 static struct dma_buf_ops udl_dmabuf_ops = {
190 .attach = udl_attach_dma_buf,
191 .detach = udl_detach_dma_buf,
192 .map_dma_buf = udl_map_dma_buf,
193 .unmap_dma_buf = udl_unmap_dma_buf,
194 .kmap = udl_dmabuf_kmap,
195 .kmap_atomic = udl_dmabuf_kmap_atomic,
196 .kunmap = udl_dmabuf_kunmap,
197 .kunmap_atomic = udl_dmabuf_kunmap_atomic,
198 .mmap = udl_dmabuf_mmap,
199 .release = drm_gem_dmabuf_release,
200 };
201
udl_gem_prime_export(struct drm_device * dev,struct drm_gem_object * obj,int flags)202 struct dma_buf *udl_gem_prime_export(struct drm_device *dev,
203 struct drm_gem_object *obj, int flags)
204 {
205 DEFINE_DMA_BUF_EXPORT_INFO(exp_info);
206
207 exp_info.ops = &udl_dmabuf_ops;
208 exp_info.size = obj->size;
209 exp_info.flags = flags;
210 exp_info.priv = obj;
211
212 return dma_buf_export(&exp_info);
213 }
214
udl_prime_create(struct drm_device * dev,size_t size,struct sg_table * sg,struct udl_gem_object ** obj_p)215 static int udl_prime_create(struct drm_device *dev,
216 size_t size,
217 struct sg_table *sg,
218 struct udl_gem_object **obj_p)
219 {
220 struct udl_gem_object *obj;
221 int npages;
222
223 npages = size / PAGE_SIZE;
224
225 *obj_p = NULL;
226 obj = udl_gem_alloc_object(dev, npages * PAGE_SIZE);
227 if (!obj)
228 return -ENOMEM;
229
230 obj->sg = sg;
231 obj->pages = drm_malloc_ab(npages, sizeof(struct page *));
232 if (obj->pages == NULL) {
233 DRM_ERROR("obj pages is NULL %d\n", npages);
234 return -ENOMEM;
235 }
236
237 drm_prime_sg_to_page_addr_arrays(sg, obj->pages, NULL, npages);
238
239 *obj_p = obj;
240 return 0;
241 }
242
udl_gem_prime_import(struct drm_device * dev,struct dma_buf * dma_buf)243 struct drm_gem_object *udl_gem_prime_import(struct drm_device *dev,
244 struct dma_buf *dma_buf)
245 {
246 struct dma_buf_attachment *attach;
247 struct sg_table *sg;
248 struct udl_gem_object *uobj;
249 int ret;
250
251 /* need to attach */
252 get_device(dev->dev);
253 attach = dma_buf_attach(dma_buf, dev->dev);
254 if (IS_ERR(attach)) {
255 put_device(dev->dev);
256 return ERR_CAST(attach);
257 }
258
259 get_dma_buf(dma_buf);
260
261 sg = dma_buf_map_attachment(attach, DMA_BIDIRECTIONAL);
262 if (IS_ERR(sg)) {
263 ret = PTR_ERR(sg);
264 goto fail_detach;
265 }
266
267 ret = udl_prime_create(dev, dma_buf->size, sg, &uobj);
268 if (ret)
269 goto fail_unmap;
270
271 uobj->base.import_attach = attach;
272 uobj->flags = UDL_BO_WC;
273
274 return &uobj->base;
275
276 fail_unmap:
277 dma_buf_unmap_attachment(attach, sg, DMA_BIDIRECTIONAL);
278 fail_detach:
279 dma_buf_detach(dma_buf, attach);
280 dma_buf_put(dma_buf);
281 put_device(dev->dev);
282 return ERR_PTR(ret);
283 }
284