1 /*
2 * Copyright (c) 2019-2020 François Tigeot <ftigeot@wolfpond.org>
3 * All rights reserved.
4 *
5 * Redistribution and use in source and binary forms, with or without
6 * modification, are permitted provided that the following conditions
7 * are met:
8 * 1. Redistributions of source code must retain the above copyright
9 * notice unmodified, this list of conditions, and the following
10 * disclaimer.
11 * 2. Redistributions in binary form must reproduce the above copyright
12 * notice, this list of conditions and the following disclaimer in the
13 * documentation and/or other materials provided with the distribution.
14 *
15 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
16 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
17 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
18 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
19 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
20 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
21 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
22 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
23 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
24 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
25 */
26
27 #include <linux/fs.h>
28 #include <linux/slab.h>
29 #include <linux/dma-buf.h>
30 #include <linux/dma-fence.h>
31 #include <linux/export.h>
32 #include <linux/module.h>
33 #include <linux/seq_file.h>
34 #include <linux/poll.h>
35 #include <linux/reservation.h>
36 #include <linux/mm.h>
37
38 static int
dmabuf_stat(struct file * fp,struct stat * sb,struct ucred * cred)39 dmabuf_stat(struct file *fp, struct stat *sb, struct ucred *cred)
40 {
41 struct dma_buf *dmabuf = fp->f_data;
42
43 memset(sb, 0, sizeof(*sb));
44 sb->st_size = dmabuf->size;
45 sb->st_mode = S_IFIFO; /* XXX */
46
47 return (0);
48 }
49
50 static int
dmabuf_close(struct file * fp)51 dmabuf_close(struct file *fp)
52 {
53 kprintf("dmabuf_close(): not implemented\n");
54 return (EINVAL);
55 }
56
57 struct fileops dmabuf_fileops = {
58 .fo_read = badfo_readwrite,
59 .fo_write = badfo_readwrite,
60 .fo_ioctl = badfo_ioctl,
61 .fo_kqfilter = badfo_kqfilter,
62 .fo_stat = dmabuf_stat,
63 .fo_close = dmabuf_close,
64 };
65
66 struct dma_buf *
dma_buf_export(const struct dma_buf_export_info * exp_info)67 dma_buf_export(const struct dma_buf_export_info *exp_info)
68 {
69 struct dma_buf *dmabuf;
70 struct file *fp;
71
72 falloc(curthread->td_lwp, &fp, NULL);
73 if (fp == NULL)
74 return ERR_PTR(-ENFILE);
75
76 dmabuf = kmalloc(sizeof(struct dma_buf), M_DRM, M_WAITOK);
77 fp->f_type = DTYPE_DMABUF;
78 fp->f_ops = &dmabuf_fileops;
79 fp->private_data = dmabuf;
80 dmabuf->priv = exp_info->priv;
81 dmabuf->ops = exp_info->ops;
82 dmabuf->size = exp_info->size;
83 dmabuf->file = fp;
84
85 return dmabuf;
86 }
87
88 int
dma_buf_fd(struct dma_buf * dmabuf,int flags)89 dma_buf_fd(struct dma_buf *dmabuf, int flags)
90 {
91 int fd, error;
92
93 if (dmabuf == NULL)
94 return -EINVAL;
95
96 if (dmabuf->file == NULL)
97 return -EINVAL;
98
99 if (flags & O_CLOEXEC) {
100 /* XXX: CLOEXEC not handled yet */
101 #if 0
102 __set_close_on_exec(fd, fdt);
103 else
104 __clear_close_on_exec(fd, fdt);
105 #endif
106 }
107
108 error = fdalloc(curproc, 0, &fd);
109 if (error != 0)
110 return -error;
111
112 fsetfd(curproc->p_fd, dmabuf->file, fd);
113
114 return fd;
115 }
116
117 struct dma_buf *
dma_buf_get(int fd)118 dma_buf_get(int fd)
119 {
120 struct file *fp;
121 struct dma_buf *dmabuf;
122
123 if ((fp = holdfp(curthread, fd, -1)) == NULL)
124 return ERR_PTR(-EBADF);
125
126 if (fp->f_ops != &dmabuf_fileops) {
127 kprintf("dma_buf_get(): file->f_ops != &dmabuf_fileops\n");
128 fdrop(fp);
129 return ERR_PTR(-EBADF);
130 }
131
132 dmabuf = fp->private_data;
133 fdrop(fp);
134
135 return dmabuf;
136 }
137
138 struct sg_table *
dma_buf_map_attachment(struct dma_buf_attachment * attach,enum dma_data_direction direction)139 dma_buf_map_attachment(struct dma_buf_attachment *attach,
140 enum dma_data_direction direction)
141 {
142 struct sg_table *sg_table;
143
144 if (attach == NULL)
145 return ERR_PTR(-EINVAL);
146
147 if (attach->dmabuf == NULL)
148 return ERR_PTR(-EINVAL);
149
150 sg_table = attach->dmabuf->ops->map_dma_buf(attach, direction);
151 if (sg_table == NULL)
152 return ERR_PTR(-ENOMEM);
153
154 return sg_table;
155 }
156
dma_buf_unmap_attachment(struct dma_buf_attachment * attach,struct sg_table * sg_table,enum dma_data_direction direction)157 void dma_buf_unmap_attachment(struct dma_buf_attachment *attach,
158 struct sg_table *sg_table,
159 enum dma_data_direction direction)
160 {
161 }
162
163