xref: /titanic_41/usr/src/uts/common/sys/uio.h (revision c037192b037119c9fd354732fc29b38ce097d356)
1 /*
2  * CDDL HEADER START
3  *
4  * The contents of this file are subject to the terms of the
5  * Common Development and Distribution License (the "License").
6  * You may not use this file except in compliance with the License.
7  *
8  * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
9  * or http://www.opensolaris.org/os/licensing.
10  * See the License for the specific language governing permissions
11  * and limitations under the License.
12  *
13  * When distributing Covered Code, include this CDDL HEADER in each
14  * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
15  * If applicable, add the following below this CDDL HEADER, with the
16  * fields enclosed by brackets "[]" replaced with your own identifying
17  * information: Portions Copyright [yyyy] [name of copyright owner]
18  *
19  * CDDL HEADER END
20  */
21 /*
22  * Copyright 2010 Sun Microsystems, Inc.  All rights reserved.
23  * Use is subject to license terms.
24  */
25 
26 /*	Copyright (c) 1984, 1986, 1987, 1988, 1989 AT&T	*/
27 /*	  All Rights Reserved  	*/
28 
29 /*
30  * University Copyright- Copyright (c) 1982, 1986, 1988
31  * The Regents of the University of California
32  * All Rights Reserved
33  *
34  * University Acknowledgment- Portions of this document are derived from
35  * software developed by the University of California, Berkeley, and its
36  * contributors.
37  */
38 
39 #ifndef _SYS_UIO_H
40 #define	_SYS_UIO_H
41 
42 #include <sys/feature_tests.h>
43 
44 #ifdef	__cplusplus
45 extern "C" {
46 #endif
47 
48 #include <sys/types.h>
49 
50 /*
51  * I/O parameter information.  A uio structure describes the I/O which
52  * is to be performed by an operation.  Typically the data movement will
53  * be performed by a routine such as uiomove(), which updates the uio
54  * structure to reflect what was done.
55  */
56 
57 #if	defined(_XPG4_2)
58 typedef struct iovec {
59 	void	*iov_base;
60 	size_t	iov_len;
61 } iovec_t;
62 #else
63 typedef struct iovec {
64 	caddr_t	iov_base;
65 #if defined(_LP64)
66 	size_t	iov_len;
67 #else
68 	long	iov_len;
69 #endif
70 } iovec_t;
71 #endif	/* defined(_XPG4_2) */
72 
73 #if defined(_SYSCALL32)
74 
75 /* Kernel's view of user ILP32 iovec struct */
76 
77 typedef	struct iovec32 {
78 	caddr32_t	iov_base;
79 	int32_t		iov_len;
80 } iovec32_t;
81 
82 #endif	/* _SYSCALL32 */
83 
84 #if 	!defined(_XPG4_2) || defined(__EXTENSIONS__)
85 /*
86  * Segment flag values.
87  */
88 typedef enum uio_seg { UIO_USERSPACE, UIO_SYSSPACE, UIO_USERISPACE } uio_seg_t;
89 
90 typedef struct uio {
91 	iovec_t		*uio_iov;	/* pointer to array of iovecs */
92 	int		uio_iovcnt;	/* number of iovecs */
93 	lloff_t		_uio_offset;	/* file offset */
94 	uio_seg_t	uio_segflg;	/* address space (kernel or user) */
95 	uint16_t	uio_fmode;	/* file mode flags */
96 	uint16_t	uio_extflg;	/* extended flags */
97 	lloff_t		_uio_limit;	/* u-limit (maximum byte offset) */
98 	ssize_t		uio_resid;	/* residual count */
99 } uio_t;
100 
101 /*
102  * Extended uio_t uioa_t used for asynchronous uio.
103  *
104  * Note: UIOA_IOV_MAX is defined and used as it is in "fs/vncalls.c"
105  *	 as there isn't a formal definition of IOV_MAX for the kernel.
106  */
107 #define	UIOA_IOV_MAX	16
108 
109 typedef struct uioa_page_s {		/* locked uio_iov state */
110 	int	uioa_pfncnt;		/* count of pfn_t(s) in *uioa_ppp */
111 	void	**uioa_ppp;		/* page_t or pfn_t arrary */
112 	caddr_t	uioa_base;		/* address base */
113 	size_t	uioa_len;		/* span length */
114 } uioa_page_t;
115 
116 typedef struct uioa_s {
117 	iovec_t		*uio_iov;	/* pointer to array of iovecs */
118 	int		uio_iovcnt;	/* number of iovecs */
119 	lloff_t		_uio_offset;	/* file offset */
120 	uio_seg_t	uio_segflg;	/* address space (kernel or user) */
121 	uint16_t	uio_fmode;	/* file mode flags */
122 	uint16_t	uio_extflg;	/* extended flags */
123 	lloff_t		_uio_limit;	/* u-limit (maximum byte offset) */
124 	ssize_t		uio_resid;	/* residual count */
125 	/*
126 	 * uioa extended members.
127 	 */
128 	uint32_t	uioa_state;	/* state of asynch i/o */
129 	ssize_t		uioa_mbytes;	/* bytes that have been uioamove()ed */
130 	uioa_page_t	*uioa_lcur;	/* pointer into uioa_locked[] */
131 	void		**uioa_lppp;	/* pointer into lcur->uioa_ppp[] */
132 	void		*uioa_hwst[4];	/* opaque hardware state */
133 	uioa_page_t	uioa_locked[UIOA_IOV_MAX]; /* Per iov locked pages */
134 } uioa_t;
135 
136 /*
137  * uio extensions
138  *
139  * PSARC 2009/478: Copy Reduction Interfaces
140  */
141 typedef enum xuio_type {
142 	UIOTYPE_ASYNCIO,
143 	UIOTYPE_ZEROCOPY
144 } xuio_type_t;
145 
146 typedef struct xuio {
147 	uio_t xu_uio;		/* Embedded UIO structure */
148 
149 	/* Extended uio fields */
150 	enum xuio_type xu_type;	/* What kind of uio structure? */
151 	union {
152 		/* Async I/O Support, intend to replace uioa_t. */
153 		struct {
154 			uint32_t xu_a_state;	/* state of async i/o */
155 			/* bytes that have been uioamove()ed */
156 			ssize_t xu_a_mbytes;
157 			uioa_page_t *xu_a_lcur;	/* pointer into uioa_locked[] */
158 			/* pointer into lcur->uioa_ppp[] */
159 			void **xu_a_lppp;
160 			void *xu_a_hwst[4];	/* opaque hardware state */
161 			/* Per iov locked pages */
162 			uioa_page_t xu_a_locked[UIOA_IOV_MAX];
163 		} xu_aio;
164 
165 		/*
166 		 * Copy Reduction Support -- facilate loaning / returning of
167 		 * filesystem cache buffers.
168 		 */
169 		struct {
170 			int xu_zc_rw;	/* read or write buffer */
171 			void *xu_zc_priv;	/* fs specific */
172 		} xu_zc;
173 	} xu_ext;
174 } xuio_t;
175 
176 #define	XUIO_XUZC_PRIV(xuio)    xuio->xu_ext.xu_zc.xu_zc_priv
177 #define	XUIO_XUZC_RW(xuio)	xuio->xu_ext.xu_zc.xu_zc_rw
178 
179 #define	UIOA_ALLOC	0x0001		/* allocated but not yet initialized */
180 #define	UIOA_INIT	0x0002		/* initialized but not yet enabled */
181 #define	UIOA_ENABLED	0x0004		/* enabled, asynch i/o active */
182 #define	UIOA_FINI	0x0008		/* finished waiting for uioafini() */
183 
184 #define	UIOA_CLR	(~0x000F)	/* clear mutually exclusive bits */
185 
186 #define	UIOA_POLL	0x0010		/* need dcopy_poll() */
187 
188 #define	uio_loffset	_uio_offset._f
189 #if !defined(_LP64)
190 #define	uio_offset	_uio_offset._p._l
191 #else
192 #define	uio_offset	uio_loffset
193 #endif
194 
195 #define	uio_llimit	_uio_limit._f
196 #if !defined(_LP64)
197 #define	uio_limit	_uio_limit._p._l
198 #else
199 #define	uio_limit	uio_llimit
200 #endif
201 
202 /*
203  * I/O direction.
204  */
205 typedef enum uio_rw { UIO_READ, UIO_WRITE } uio_rw_t;
206 
207 /*
208  * uio_extflg: extended flags
209  *
210  * NOTE: This flag will be used in uiomove to determine if non-temporal
211  * access, ie, access bypassing caches, should be used.  Filesystems that
212  * don't initialize this field could experience suboptimal performance due to
213  * the random data the field contains.
214  *
215  * NOTE: This flag is also used by uioasync callers to pass an extended
216  * uio_t (uioa_t), to uioasync enabled consumers. Unlike above all
217  * consumers of a uioa_t require the uio_extflg to be initialized.
218  */
219 #define	UIO_COPY_DEFAULT	0x0000	/* no special options to copy */
220 #define	UIO_COPY_CACHED		0x0001	/* copy should not bypass caches */
221 
222 #define	UIO_ASYNC		0x0002	/* uio_t is really a uioa_t */
223 #define	UIO_XUIO		0x0004	/* Structure is xuio_t */
224 
225 /*
226  * Global uioasync capability shadow state.
227  */
228 typedef struct uioasync_s {
229 	boolean_t	enabled;	/* Is uioasync enabled? */
230 	size_t		mincnt;		/* Minimum byte count for use of */
231 } uioasync_t;
232 
233 #endif /* !defined(_XPG4_2) || defined(__EXTENSIONS__) */
234 
235 #if	defined(_KERNEL)
236 
237 int	uiomove(void *, size_t, enum uio_rw, uio_t *);
238 void	uio_prefaultpages(ssize_t, uio_t *);
239 int	uiocopy(void *, size_t, enum uio_rw, uio_t *, size_t *);
240 int	ureadc(int, uio_t *);	/* should be errno_t in future */
241 int	uwritec(struct uio *);
242 void	uioskip(uio_t *, size_t);
243 int	uiodup(uio_t *, uio_t *, iovec_t *, int);
244 
245 int	uioamove(void *, size_t, enum uio_rw, uioa_t *);
246 int	uioainit(uio_t *, uioa_t *);
247 int	uioafini(uio_t *, uioa_t *);
248 extern	uioasync_t uioasync;
249 
250 #else	/* defined(_KERNEL) */
251 
252 #if 	defined(__STDC__)
253 
254 extern ssize_t readv(int, const struct iovec *, int);
255 extern ssize_t writev(int, const struct iovec *, int);
256 
257 #else	/* defined(__STDC__) */
258 
259 extern ssize_t readv();
260 extern ssize_t writev();
261 
262 #endif	/* defined(__STDC__) */
263 
264 #endif	/* defined(_KERNEL) */
265 
266 #ifdef	__cplusplus
267 }
268 #endif
269 
270 #endif	/* _SYS_UIO_H */
271