xref: /titanic_41/usr/src/uts/common/sys/uio.h (revision dfa1896db444d8b104da7cb009f39f1a89a438aa)
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 2014 Garrett D'Amore <garrett@damore.org>
23  *
24  * Copyright 2010 Sun Microsystems, Inc.  All rights reserved.
25  * Use is subject to license terms.
26  * Copyright (c) 2015, Joyent, Inc.  All rights reserved.
27  */
28 
29 /*	Copyright (c) 1984, 1986, 1987, 1988, 1989 AT&T	*/
30 /*	  All Rights Reserved  	*/
31 
32 /*
33  * University Copyright- Copyright (c) 1982, 1986, 1988
34  * The Regents of the University of California
35  * All Rights Reserved
36  *
37  * University Acknowledgment- Portions of this document are derived from
38  * software developed by the University of California, Berkeley, and its
39  * contributors.
40  */
41 
42 #ifndef _SYS_UIO_H
43 #define	_SYS_UIO_H
44 
45 #include <sys/feature_tests.h>
46 
47 #ifdef	__cplusplus
48 extern "C" {
49 #endif
50 
51 #include <sys/types.h>
52 
53 /*
54  * I/O parameter information.  A uio structure describes the I/O which
55  * is to be performed by an operation.  Typically the data movement will
56  * be performed by a routine such as uiomove(), which updates the uio
57  * structure to reflect what was done.
58  */
59 
60 #if	defined(_XPG4_2)
61 typedef struct iovec {
62 	void	*iov_base;
63 	size_t	iov_len;
64 } iovec_t;
65 #else
66 typedef struct iovec {
67 	caddr_t	iov_base;
68 #if defined(_LP64)
69 	size_t	iov_len;
70 #else
71 	long	iov_len;
72 #endif
73 } iovec_t;
74 #endif	/* defined(_XPG4_2) */
75 
76 #if defined(_SYSCALL32)
77 
78 /* Kernel's view of user ILP32 iovec struct */
79 
80 typedef	struct iovec32 {
81 	caddr32_t	iov_base;
82 	int32_t		iov_len;
83 } iovec32_t;
84 
85 #endif	/* _SYSCALL32 */
86 
87 #if 	!defined(_XPG4_2) || defined(__EXTENSIONS__)
88 /*
89  * Segment flag values.
90  */
91 typedef enum uio_seg { UIO_USERSPACE, UIO_SYSSPACE, UIO_USERISPACE } uio_seg_t;
92 
93 typedef struct uio {
94 	iovec_t		*uio_iov;	/* pointer to array of iovecs */
95 	int		uio_iovcnt;	/* number of iovecs */
96 	lloff_t		_uio_offset;	/* file offset */
97 	uio_seg_t	uio_segflg;	/* address space (kernel or user) */
98 	uint16_t	uio_fmode;	/* file mode flags */
99 	uint16_t	uio_extflg;	/* extended flags */
100 	lloff_t		_uio_limit;	/* u-limit (maximum byte offset) */
101 	ssize_t		uio_resid;	/* residual count */
102 } uio_t;
103 
104 /*
105  * Extended uio_t uioa_t used for asynchronous uio.
106  *
107  * Note: UIOA_IOV_MAX is defined and used as it is in "fs/vncalls.c"
108  *	 as there isn't a formal definition of IOV_MAX for the kernel.
109  */
110 #define	UIOA_IOV_MAX	16
111 
112 typedef struct uioa_page_s {		/* locked uio_iov state */
113 	int	uioa_pfncnt;		/* count of pfn_t(s) in *uioa_ppp */
114 	void	**uioa_ppp;		/* page_t or pfn_t arrary */
115 	caddr_t	uioa_base;		/* address base */
116 	size_t	uioa_len;		/* span length */
117 } uioa_page_t;
118 
119 typedef struct uioa_s {
120 	iovec_t		*uio_iov;	/* pointer to array of iovecs */
121 	int		uio_iovcnt;	/* number of iovecs */
122 	lloff_t		_uio_offset;	/* file offset */
123 	uio_seg_t	uio_segflg;	/* address space (kernel or user) */
124 	uint16_t	uio_fmode;	/* file mode flags */
125 	uint16_t	uio_extflg;	/* extended flags */
126 	lloff_t		_uio_limit;	/* u-limit (maximum byte offset) */
127 	ssize_t		uio_resid;	/* residual count */
128 	/*
129 	 * uioa extended members.
130 	 */
131 	uint32_t	uioa_state;	/* state of asynch i/o */
132 	ssize_t		uioa_mbytes;	/* bytes that have been uioamove()ed */
133 	uioa_page_t	*uioa_lcur;	/* pointer into uioa_locked[] */
134 	void		**uioa_lppp;	/* pointer into lcur->uioa_ppp[] */
135 	void		*uioa_hwst[4];	/* opaque hardware state */
136 	uioa_page_t	uioa_locked[UIOA_IOV_MAX]; /* Per iov locked pages */
137 } uioa_t;
138 
139 /*
140  * uio extensions
141  *
142  * PSARC 2009/478: Copy Reduction Interfaces
143  */
144 typedef enum xuio_type {
145 	UIOTYPE_ASYNCIO,
146 	UIOTYPE_ZEROCOPY
147 } xuio_type_t;
148 
149 typedef struct xuio {
150 	uio_t xu_uio;		/* Embedded UIO structure */
151 
152 	/* Extended uio fields */
153 	enum xuio_type xu_type;	/* What kind of uio structure? */
154 	union {
155 		/* Async I/O Support, intend to replace uioa_t. */
156 		struct {
157 			uint32_t xu_a_state;	/* state of async i/o */
158 			/* bytes that have been uioamove()ed */
159 			ssize_t xu_a_mbytes;
160 			uioa_page_t *xu_a_lcur;	/* pointer into uioa_locked[] */
161 			/* pointer into lcur->uioa_ppp[] */
162 			void **xu_a_lppp;
163 			void *xu_a_hwst[4];	/* opaque hardware state */
164 			/* Per iov locked pages */
165 			uioa_page_t xu_a_locked[UIOA_IOV_MAX];
166 		} xu_aio;
167 
168 		/*
169 		 * Copy Reduction Support -- facilate loaning / returning of
170 		 * filesystem cache buffers.
171 		 */
172 		struct {
173 			int xu_zc_rw;	/* read or write buffer */
174 			void *xu_zc_priv;	/* fs specific */
175 		} xu_zc;
176 	} xu_ext;
177 } xuio_t;
178 
179 #define	XUIO_XUZC_PRIV(xuio)    xuio->xu_ext.xu_zc.xu_zc_priv
180 #define	XUIO_XUZC_RW(xuio)	xuio->xu_ext.xu_zc.xu_zc_rw
181 
182 #define	UIOA_ALLOC	0x0001		/* allocated but not yet initialized */
183 #define	UIOA_INIT	0x0002		/* initialized but not yet enabled */
184 #define	UIOA_ENABLED	0x0004		/* enabled, asynch i/o active */
185 #define	UIOA_FINI	0x0008		/* finished waiting for uioafini() */
186 
187 #define	UIOA_CLR	(~0x000F)	/* clear mutually exclusive bits */
188 
189 #define	UIOA_POLL	0x0010		/* need dcopy_poll() */
190 
191 #define	uio_loffset	_uio_offset._f
192 #if !defined(_LP64)
193 #define	uio_offset	_uio_offset._p._l
194 #else
195 #define	uio_offset	uio_loffset
196 #endif
197 
198 #define	uio_llimit	_uio_limit._f
199 #if !defined(_LP64)
200 #define	uio_limit	_uio_limit._p._l
201 #else
202 #define	uio_limit	uio_llimit
203 #endif
204 
205 /*
206  * I/O direction.
207  */
208 typedef enum uio_rw { UIO_READ, UIO_WRITE } uio_rw_t;
209 
210 /*
211  * uio_extflg: extended flags
212  *
213  * NOTE: This flag will be used in uiomove to determine if non-temporal
214  * access, ie, access bypassing caches, should be used.  Filesystems that
215  * don't initialize this field could experience suboptimal performance due to
216  * the random data the field contains.
217  *
218  * NOTE: This flag is also used by uioasync callers to pass an extended
219  * uio_t (uioa_t), to uioasync enabled consumers. Unlike above all
220  * consumers of a uioa_t require the uio_extflg to be initialized.
221  */
222 #define	UIO_COPY_DEFAULT	0x0000	/* no special options to copy */
223 #define	UIO_COPY_CACHED		0x0001	/* copy should not bypass caches */
224 
225 #define	UIO_ASYNC		0x0002	/* uio_t is really a uioa_t */
226 #define	UIO_XUIO		0x0004	/* Structure is xuio_t */
227 
228 /*
229  * Global uioasync capability shadow state.
230  */
231 typedef struct uioasync_s {
232 	boolean_t	enabled;	/* Is uioasync enabled? */
233 	size_t		mincnt;		/* Minimum byte count for use of */
234 } uioasync_t;
235 
236 #endif /* !defined(_XPG4_2) || defined(__EXTENSIONS__) */
237 
238 #if	defined(_KERNEL)
239 
240 int	uiomove(void *, size_t, enum uio_rw, uio_t *);
241 void	uio_prefaultpages(ssize_t, uio_t *);
242 int	uiocopy(void *, size_t, enum uio_rw, uio_t *, size_t *);
243 int	ureadc(int, uio_t *);	/* should be errno_t in future */
244 int	uwritec(struct uio *);
245 void	uioskip(uio_t *, size_t);
246 int	uiodup(uio_t *, uio_t *, iovec_t *, int);
247 
248 int	uioamove(void *, size_t, enum uio_rw, uioa_t *);
249 int	uioainit(uio_t *, uioa_t *);
250 int	uioafini(uio_t *, uioa_t *);
251 extern	uioasync_t uioasync;
252 
253 #else	/* defined(_KERNEL) */
254 
255 extern ssize_t readv(int, const struct iovec *, int);
256 extern ssize_t writev(int, const struct iovec *, int);
257 
258 /*
259  * When in the large file compilation environment,
260  * map preadv/pwritev to their 64 bit offset versions
261  */
262 #if !defined(_LP64) && _FILE_OFFSET_BITS == 64
263 #ifdef __PRAGMA_REDEFINE_EXTNAME
264 #pragma	redefine_extname	preadv	preadv64
265 #pragma	redefine_extname	pwritev	pwritev64
266 #else /* __PRAGMA_REDEFINE_EXTNAME */
267 #define	preadv	preadv64
268 #define	pwritev	pwritev64
269 #endif /* __PRAGMA_REDEFINE_EXTNAME */
270 #endif /* !_LP64 && _FILE_OFFSET_BITS == 64 */
271 
272 /* In the LP64 compilation environment, the APIs are already large file */
273 #if defined(_LP64) && defined(_LARGEFILE64_SOURCE)
274 #ifdef  __PRAGMA_REDEFINE_EXTNAME
275 #pragma	redefine_extname	preadv64	preadv
276 #pragma	redefine_extname	pwritev64	pwritev
277 #else   /* __PRAGMA_REDEFINE_EXTNAME */
278 #define	preadv64	preadv
279 #define	pwritev64	pwritev
280 #endif  /* __PRAGMA_REDEFINE_EXTNAME */
281 #endif  /* _LP64 && _LARGEFILE64_SOURCE */
282 
283 extern ssize_t preadv(int, const struct iovec *, int, off_t);
284 extern ssize_t pwritev(int, const struct iovec *, int, off_t);
285 
286 /*
287  * preadv64 and pwritev64 should be defined when:
288  * - Using the transitional compilation environment, and not
289  *     the large file compilation environment.
290  */
291 #if defined(_LARGEFILE64_SOURCE) && !((_FILE_OFFSET_BITS == 64) && \
292 	!defined(__PRAGMA_REDEFINE_EXTNAME))
293 extern ssize_t preadv64(int, const struct iovec *, int, off64_t);
294 extern ssize_t pwritev64(int, const struct iovec *, int, off64_t);
295 #endif /* _LARGEFILE64_SOURCE */
296 
297 #endif	/* defined(_KERNEL) */
298 
299 #ifdef	__cplusplus
300 }
301 #endif
302 
303 #endif	/* _SYS_UIO_H */
304