1 /*
2 * Copyright (c) 2018-2020 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 #ifndef LINUX_DMA_BUF_H
28 #define LINUX_DMA_BUF_H
29
30 #include <linux/err.h>
31 #include <linux/scatterlist.h>
32 #include <linux/list.h>
33 #include <linux/dma-mapping.h>
34 #include <linux/fs.h>
35 #include <linux/dma-fence.h>
36 #include <linux/wait.h>
37
38 #include <linux/slab.h>
39
40 struct dma_buf;
41 struct dma_buf_attachment;
42
43 struct dma_buf_ops {
44 struct sg_table * (*map_dma_buf)(struct dma_buf_attachment *,
45 enum dma_data_direction);
46 void (*unmap_dma_buf)(struct dma_buf_attachment *,
47 struct sg_table *,
48 enum dma_data_direction);
49 void (*release)(struct dma_buf *);
50 void *(*map)(struct dma_buf *, unsigned long);
51 void *(*map_atomic)(struct dma_buf *, unsigned long);
52 void (*unmap)(struct dma_buf *, unsigned long, void *);
53 void (*unmap_atomic)(struct dma_buf *, unsigned long, void *);
54 int (*mmap)(struct dma_buf *, struct vm_area_struct *vma);
55 void *(*vmap)(struct dma_buf *);
56 void (*vunmap)(struct dma_buf *, void *vaddr);
57 int (*begin_cpu_access)(struct dma_buf *, enum dma_data_direction);
58 int (*end_cpu_access)(struct dma_buf *, enum dma_data_direction);
59 int (*attach)(struct dma_buf *, struct device *, struct dma_buf_attachment *);
60 void (*detach)(struct dma_buf *, struct dma_buf_attachment *);
61 };
62
63 struct dma_buf {
64 struct reservation_object *resv;
65 void *priv;
66 const struct dma_buf_ops *ops;
67 size_t size;
68 struct file *file;
69 };
70
71 struct dma_buf_attachment {
72 struct dma_buf *dmabuf;
73 struct device *dev;
74 void *priv;
75 };
76
77 struct dma_buf_export_info {
78 const struct dma_buf_ops *ops;
79 size_t size;
80 int flags;
81 void *priv;
82 struct reservation_object *resv;
83 };
84
85 struct dma_buf *dma_buf_export(const struct dma_buf_export_info *exp_info);
86
87 #define DEFINE_DMA_BUF_EXPORT_INFO(name) \
88 struct dma_buf_export_info name = { \
89 }
90
91 struct sg_table * dma_buf_map_attachment(struct dma_buf_attachment *,
92 enum dma_data_direction);
93 void dma_buf_unmap_attachment(struct dma_buf_attachment *,
94 struct sg_table *, enum dma_data_direction);
95
96 static inline struct dma_buf_attachment *
dma_buf_attach(struct dma_buf * dmabuf,struct device * dev)97 dma_buf_attach(struct dma_buf *dmabuf, struct device *dev)
98 {
99 /* XXX: this function is a stub */
100 struct dma_buf_attachment *attach;
101
102 attach = kmalloc(sizeof(struct dma_buf_attachment), M_DRM, M_WAITOK | M_ZERO);
103
104 return attach;
105 }
106
107 static inline void
get_dma_buf(struct dma_buf * dmabuf)108 get_dma_buf(struct dma_buf *dmabuf)
109 {
110 fhold(dmabuf->file);
111 }
112
113 static inline void
dma_buf_put(struct dma_buf * dmabuf)114 dma_buf_put(struct dma_buf *dmabuf)
115 {
116 if (dmabuf == NULL)
117 return;
118
119 if (dmabuf->file == NULL)
120 return;
121
122 fdrop(dmabuf->file);
123 }
124
125 int dma_buf_fd(struct dma_buf *dmabuf, int flags);
126
127 struct dma_buf *dma_buf_get(int fd);
128
129 static inline void
dma_buf_detach(struct dma_buf * dmabuf,struct dma_buf_attachment * dmabuf_attach)130 dma_buf_detach(struct dma_buf *dmabuf,
131 struct dma_buf_attachment *dmabuf_attach)
132 {
133 kprintf("dma_buf_detach: Not implemented\n");
134 }
135
136 #endif /* LINUX_DMA_BUF_H */
137