AMD64 - Refactor uio_resid and size_t assumptions.
[dragonfly.git] / sys / sys / xio.h
CommitLineData
81ee925d 1/*
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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 *
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7 * Redistribution and use in source and binary forms, with or without
8 * modification, are permitted provided that the following conditions
9 * are met:
8c10bfcf 10 *
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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
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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
81ee925d 32 * SUCH DAMAGE.
8c10bfcf 33 *
83269e7d 34 * $DragonFly: src/sys/sys/xio.h,v 1.10 2007/08/13 17:20:05 dillon Exp $
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35 */
36
37/*
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38 * An XIO holds a platform-agnostic page list representing a data set for
39 * the purposes of I/O, mapping (SFBUF/MSFBUF), or other operations. The
40 * representation of the data set is byte aligned. xio_offset and xio_bytes
41 * specifies the precise byte-ranged block within the page list being
42 * represented.
43 *
44 * XIOs do not track an ongoing I/O, they simply represent a block of data.
45 * For this reason most XIO API functions have a 'uoffset' argument which
46 * the caller may use to index within the represented dataset. This index
47 * is relative to the represented dataset, NOT to the beginning of the
48 * first page.
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49 */
50#ifndef _SYS_XIO_H_
51#define _SYS_XIO_H_
52
53#if defined(_KERNEL) || defined(_KERNEL_STRUCTURES)
54
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55#ifndef _SYS_TYPES_H_
56#include <sys/types.h>
57#endif
58#ifndef _SYS_UIO_H_
59#include <sys/uio.h>
60#endif
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61#ifndef _SYS_MSGPORT_H_
62#include <sys/msgport.h>
63#endif
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64#ifndef _MACHINE_PARAM_H_
65#include <machine/param.h>
66#endif
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67
68#define XIO_INTERNAL_PAGES btoc(MAXPHYS)
69#define XIO_INTERNAL_SIZE (XIO_INTERNAL_PAGES * PAGE_SIZE)
70
71struct vm_page;
72
73struct xio {
74 struct vm_page **xio_pages;
75 int xio_npages; /* number of pages in xio_pages[] array */
76 int xio_offset; /* byte offset (may exceed a page) */
77 int xio_bytes; /* number of bytes to transfer */
78 int xio_flags;
79 int xio_error;
80 struct vm_page *xio_internal_pages[XIO_INTERNAL_PAGES];
81};
82
83typedef struct xio *xio_t;
84
85#define XIOF_READ 0x0001
86#define XIOF_WRITE 0x0002
c4734fe7 87#define XIOF_VMLINEAR 0x0004 /* must be VM object linear */
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88
89#endif
90
91#if defined(_KERNEL)
92
52c90fbc 93void xio_init(xio_t xio);
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94int xio_init_ubuf(xio_t xio, void *ubase, size_t ubytes, int vmprot);
95int xio_init_kbuf(xio_t xio, void *kbase, size_t kbytes);
83269e7d 96int xio_init_pages(xio_t xio, struct vm_page **mbase, int npages, int xflags);
81ee925d 97void xio_release(xio_t xio);
e54488bb 98int xio_uio_copy(xio_t xio, int uoffset, struct uio *uio, size_t *sizep);
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99int xio_copy_xtou(xio_t xio, int uoffset, void *uptr, int bytes);
100int xio_copy_xtok(xio_t xio, int uoffset, void *kptr, int bytes);
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101int xio_copy_utox(xio_t xio, int uoffset, const void *uptr, int bytes);
102int xio_copy_ktox(xio_t xio, int uoffset, const void *kptr, int bytes);
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103
104/*
105 * XIOs are not modified by copy operations, the caller must track the
106 * offset itself. This routine will return the number of bytes remaining
107 * in an XIO's buffer given an offset relative to the buffer used to
108 * originally construct the XIO.
109 */
110static __inline
111int
112xio_remaining(xio_t xio, int uoffset)
113{
114 return(xio->xio_bytes - uoffset);
115}
116
117/*
118 * XIOs do not map data but if the page list WERE mapped, this routine will
119 * return the actual KVA offset given a user offset relative to the original
120 * buffer used to construct the XIO.
121 */
122static __inline
123int
124xio_kvaoffset(xio_t xio, int uoffset)
125{
126 return(xio->xio_offset + uoffset);
127}
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128
129#endif /* _KERNEL */
130
693cbfd3 131#endif /* !_SYS_XIO_H_ */