ssb: remove the ssb DMA API
[linux-2.6.git] / include / linux / splice.h
1 /*
2  * Function declerations and data structures related to the splice
3  * implementation.
4  *
5  * Copyright (C) 2007 Jens Axboe <jens.axboe@oracle.com>
6  *
7  */
8 #ifndef SPLICE_H
9 #define SPLICE_H
10
11 #include <linux/pipe_fs_i.h>
12
13 /*
14  * Flags passed in from splice/tee/vmsplice
15  */
16 #define SPLICE_F_MOVE   (0x01)  /* move pages instead of copying */
17 #define SPLICE_F_NONBLOCK (0x02) /* don't block on the pipe splicing (but */
18                                  /* we may still block on the fd we splice */
19                                  /* from/to, of course */
20 #define SPLICE_F_MORE   (0x04)  /* expect more data */
21 #define SPLICE_F_GIFT   (0x08)  /* pages passed in are a gift */
22
23 /*
24  * Passed to the actors
25  */
26 struct splice_desc {
27         unsigned int len, total_len;    /* current and remaining length */
28         unsigned int flags;             /* splice flags */
29         /*
30          * actor() private data
31          */
32         union {
33                 void __user *userptr;   /* memory to write to */
34                 struct file *file;      /* file to read/write */
35                 void *data;             /* cookie */
36         } u;
37         loff_t pos;                     /* file position */
38         size_t num_spliced;             /* number of bytes already spliced */
39         bool need_wakeup;               /* need to wake up writer */
40 };
41
42 struct partial_page {
43         unsigned int offset;
44         unsigned int len;
45         unsigned long private;
46 };
47
48 /*
49  * Passed to splice_to_pipe
50  */
51 struct splice_pipe_desc {
52         struct page **pages;            /* page map */
53         struct partial_page *partial;   /* pages[] may not be contig */
54         int nr_pages;                   /* number of pages in map */
55         unsigned int flags;             /* splice flags */
56         const struct pipe_buf_operations *ops;/* ops associated with output pipe */
57         void (*spd_release)(struct splice_pipe_desc *, unsigned int);
58 };
59
60 typedef int (splice_actor)(struct pipe_inode_info *, struct pipe_buffer *,
61                            struct splice_desc *);
62 typedef int (splice_direct_actor)(struct pipe_inode_info *,
63                                   struct splice_desc *);
64
65 extern ssize_t splice_from_pipe(struct pipe_inode_info *, struct file *,
66                                 loff_t *, size_t, unsigned int,
67                                 splice_actor *);
68 extern ssize_t __splice_from_pipe(struct pipe_inode_info *,
69                                   struct splice_desc *, splice_actor *);
70 extern int splice_from_pipe_feed(struct pipe_inode_info *, struct splice_desc *,
71                                  splice_actor *);
72 extern int splice_from_pipe_next(struct pipe_inode_info *,
73                                  struct splice_desc *);
74 extern void splice_from_pipe_begin(struct splice_desc *);
75 extern void splice_from_pipe_end(struct pipe_inode_info *,
76                                  struct splice_desc *);
77 extern int pipe_to_file(struct pipe_inode_info *, struct pipe_buffer *,
78                         struct splice_desc *);
79
80 extern ssize_t splice_to_pipe(struct pipe_inode_info *,
81                               struct splice_pipe_desc *);
82 extern ssize_t splice_direct_to_actor(struct file *, struct splice_desc *,
83                                       splice_direct_actor *);
84
85 #endif