1 /*
2 * Copyright (c) 2003,2004 The DragonFly Project. All rights reserved.
3 *
4 * This code is derived from software contributed to The DragonFly Project
5 * by Matthew Dillon <dillon@backplane.com>
6 *
7 * Redistribution and use in source and binary forms, with or without
8 * modification, are permitted provided that the following conditions
9 * are met:
10 *
11 * 1. Redistributions of source code must retain the above copyright
12 * notice, this list of conditions and the following disclaimer.
13 * 2. Redistributions in binary form must reproduce the above copyright
14 * notice, this list of conditions and the following disclaimer in
15 * the documentation and/or other materials provided with the
16 * distribution.
17 * 3. Neither the name of The DragonFly Project nor the names of its
18 * contributors may be used to endorse or promote products derived
19 * from this software without specific, prior written permission.
20 *
21 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
22 * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
23 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
24 * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
25 * COPYRIGHT HOLDERS OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
26 * INCIDENTAL, SPECIAL, EXEMPLARY OR CONSEQUENTIAL DAMAGES (INCLUDING,
27 * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
28 * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
29 * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
30 * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT
31 * OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
32 * SUCH DAMAGE.
33 */
34
35 /*
36 * An XIO holds a platform-agnostic page list representing a data set for
37 * the purposes of I/O, mapping (SFBUF/MSFBUF), or other operations. The
38 * representation of the data set is byte aligned. xio_offset and xio_bytes
39 * specifies the precise byte-ranged block within the page list being
40 * represented.
41 *
42 * XIOs do not track an ongoing I/O, they simply represent a block of data.
43 * For this reason most XIO API functions have a 'uoffset' argument which
44 * the caller may use to index within the represented dataset. This index
45 * is relative to the represented dataset, NOT to the beginning of the
46 * first page.
47 */
48 #ifndef _SYS_XIO_H_
49 #define _SYS_XIO_H_
50
51 #if defined(_KERNEL) || defined(_KERNEL_STRUCTURES)
52
53 #ifndef _SYS_TYPES_H_
54 #include <sys/types.h>
55 #endif
56 #ifndef _SYS__UIO_H_
57 #include <sys/_uio.h>
58 #endif
59 #ifndef _SYS_MSGPORT_H_
60 #include <sys/msgport.h>
61 #endif
62 #ifndef _MACHINE_PARAM_H_
63 #include <machine/param.h>
64 #endif
65
66 #define XIO_INTERNAL_PAGES btoc(MAXPHYS)
67 #define XIO_INTERNAL_SIZE (XIO_INTERNAL_PAGES * PAGE_SIZE)
68
69 struct vm_page;
70
71 struct xio {
72 struct vm_page **xio_pages;
73 int xio_npages; /* number of pages in xio_pages[] array */
74 int xio_offset; /* byte offset (may exceed a page) */
75 int xio_bytes; /* number of bytes to transfer */
76 int xio_flags;
77 int xio_error;
78 struct vm_page *xio_internal_pages[XIO_INTERNAL_PAGES];
79 };
80
81 typedef struct xio *xio_t;
82
83 #define XIOF_READ 0x0001
84 #define XIOF_WRITE 0x0002
85 #define XIOF_VMLINEAR 0x0004 /* must be VM object linear */
86
87 #endif
88
89 #if defined(_KERNEL)
90
91 void xio_init(xio_t xio);
92 int xio_init_kbuf(xio_t xio, void *kbase, size_t kbytes);
93 int xio_init_pages(xio_t xio, struct vm_page **mbase, int npages, int xflags);
94 void xio_release(xio_t xio);
95 int xio_uio_copy(xio_t xio, int uoffset, struct uio *uio, size_t *sizep);
96 int xio_copy_xtou(xio_t xio, int uoffset, void *uptr, int bytes);
97 int xio_copy_xtok(xio_t xio, int uoffset, void *kptr, int bytes);
98 int xio_copy_utox(xio_t xio, int uoffset, const void *uptr, int bytes);
99 int xio_copy_ktox(xio_t xio, int uoffset, const void *kptr, int bytes);
100
101 /*
102 * XIOs are not modified by copy operations, the caller must track the
103 * offset itself. This routine will return the number of bytes remaining
104 * in an XIO's buffer given an offset relative to the buffer used to
105 * originally construct the XIO.
106 */
107 static __inline
108 int
xio_remaining(xio_t xio,int uoffset)109 xio_remaining(xio_t xio, int uoffset)
110 {
111 return(xio->xio_bytes - uoffset);
112 }
113
114 /*
115 * XIOs do not map data but if the page list WERE mapped, this routine will
116 * return the actual KVA offset given a user offset relative to the original
117 * buffer used to construct the XIO.
118 */
119 static __inline
120 int
xio_kvaoffset(xio_t xio,int uoffset)121 xio_kvaoffset(xio_t xio, int uoffset)
122 {
123 return(xio->xio_offset + uoffset);
124 }
125
126 #endif /* _KERNEL */
127
128 #endif /* !_SYS_XIO_H_ */
129