1 /*
2  *  Copyright (C) 2007-2010 Lawrence Livermore National Security, LLC.
3  *  Copyright (C) 2007 The Regents of the University of California.
4  *  Copyright (c) 2015 by Chunwei Chen. All rights reserved.
5  *  Produced at Lawrence Livermore National Laboratory (cf, DISCLAIMER).
6  *  Written by Brian Behlendorf <[email protected]>.
7  *  UCRL-CODE-235197
8  *
9  *  This file is part of the SPL, Solaris Porting Layer.
10  *
11  *  The SPL is free software; you can redistribute it and/or modify it
12  *  under the terms of the GNU General Public License as published by the
13  *  Free Software Foundation; either version 2 of the License, or (at your
14  *  option) any later version.
15  *
16  *  The SPL is distributed in the hope that it will be useful, but WITHOUT
17  *  ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
18  *  FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
19  *  for more details.
20  *
21  *  You should have received a copy of the GNU General Public License along
22  *  with the SPL.  If not, see <http://www.gnu.org/licenses/>.
23  */
24 
25 #ifndef _SPL_UIO_H
26 #define	_SPL_UIO_H
27 
28 #include <sys/debug.h>
29 #include <linux/uio.h>
30 #include <linux/blkdev.h>
31 #include <linux/blkdev_compat.h>
32 #include <linux/mm.h>
33 #include <linux/bio.h>
34 #include <asm/uaccess.h>
35 #include <sys/types.h>
36 
37 typedef struct iovec iovec_t;
38 
39 typedef enum uio_rw {
40 	UIO_READ =		0,
41 	UIO_WRITE =		1,
42 } uio_rw_t;
43 
44 typedef enum uio_seg {
45 	UIO_USERSPACE =		0,
46 	UIO_SYSSPACE =		1,
47 	UIO_BVEC =		2,
48 #if defined(HAVE_VFS_IOV_ITER)
49 	UIO_ITER =		3,
50 #endif
51 } uio_seg_t;
52 
53 typedef struct uio {
54 	union {
55 		const struct iovec	*uio_iov;
56 		const struct bio_vec	*uio_bvec;
57 #if defined(HAVE_VFS_IOV_ITER)
58 		struct iov_iter		*uio_iter;
59 #endif
60 	};
61 	int		uio_iovcnt;
62 	offset_t	uio_loffset;
63 	uio_seg_t	uio_segflg;
64 	boolean_t	uio_fault_disable;
65 	uint16_t	uio_fmode;
66 	uint16_t	uio_extflg;
67 	ssize_t		uio_resid;
68 	size_t		uio_skip;
69 } uio_t;
70 
71 #define	uio_segflg(uio)			(uio)->uio_segflg
72 #define	uio_offset(uio)			(uio)->uio_loffset
73 #define	uio_resid(uio)			(uio)->uio_resid
74 #define	uio_iovcnt(uio)			(uio)->uio_iovcnt
75 #define	uio_iovlen(uio, idx)		(uio)->uio_iov[(idx)].iov_len
76 #define	uio_iovbase(uio, idx)		(uio)->uio_iov[(idx)].iov_base
77 #define	uio_fault_disable(uio, set)	(uio)->uio_fault_disable = set
78 
79 static inline void
uio_iov_at_index(uio_t * uio,uint_t idx,void ** base,uint64_t * len)80 uio_iov_at_index(uio_t *uio, uint_t idx, void **base, uint64_t *len)
81 {
82 	*base = uio_iovbase(uio, idx);
83 	*len = uio_iovlen(uio, idx);
84 }
85 
86 static inline void
uio_advance(uio_t * uio,size_t size)87 uio_advance(uio_t *uio, size_t size)
88 {
89 	uio->uio_resid -= size;
90 	uio->uio_loffset += size;
91 }
92 
93 static inline offset_t
uio_index_at_offset(uio_t * uio,offset_t off,uint_t * vec_idx)94 uio_index_at_offset(uio_t *uio, offset_t off, uint_t *vec_idx)
95 {
96 	*vec_idx = 0;
97 	while (*vec_idx < uio_iovcnt(uio) && off >= uio_iovlen(uio, *vec_idx)) {
98 		off -= uio_iovlen(uio, *vec_idx);
99 		(*vec_idx)++;
100 	}
101 
102 	return (off);
103 }
104 
105 static inline void
iov_iter_init_compat(struct iov_iter * iter,unsigned int dir,const struct iovec * iov,unsigned long nr_segs,size_t count)106 iov_iter_init_compat(struct iov_iter *iter, unsigned int dir,
107     const struct iovec *iov, unsigned long nr_segs, size_t count)
108 {
109 #if defined(HAVE_IOV_ITER_INIT)
110 	iov_iter_init(iter, dir, iov, nr_segs, count);
111 #elif defined(HAVE_IOV_ITER_INIT_LEGACY)
112 	iov_iter_init(iter, iov, nr_segs, count, 0);
113 #else
114 #error "Unsupported kernel"
115 #endif
116 }
117 
118 static inline void
uio_iovec_init(uio_t * uio,const struct iovec * iov,unsigned long nr_segs,offset_t offset,uio_seg_t seg,ssize_t resid,size_t skip)119 uio_iovec_init(uio_t *uio, const struct iovec *iov, unsigned long nr_segs,
120     offset_t offset, uio_seg_t seg, ssize_t resid, size_t skip)
121 {
122 	ASSERT(seg == UIO_USERSPACE || seg == UIO_SYSSPACE);
123 
124 	uio->uio_iov = iov;
125 	uio->uio_iovcnt = nr_segs;
126 	uio->uio_loffset = offset;
127 	uio->uio_segflg = seg;
128 	uio->uio_fault_disable = B_FALSE;
129 	uio->uio_fmode = 0;
130 	uio->uio_extflg = 0;
131 	uio->uio_resid = resid;
132 	uio->uio_skip = skip;
133 }
134 
135 static inline void
uio_bvec_init(uio_t * uio,struct bio * bio)136 uio_bvec_init(uio_t *uio, struct bio *bio)
137 {
138 	uio->uio_bvec = &bio->bi_io_vec[BIO_BI_IDX(bio)];
139 	uio->uio_iovcnt = bio->bi_vcnt - BIO_BI_IDX(bio);
140 	uio->uio_loffset = BIO_BI_SECTOR(bio) << 9;
141 	uio->uio_segflg = UIO_BVEC;
142 	uio->uio_fault_disable = B_FALSE;
143 	uio->uio_fmode = 0;
144 	uio->uio_extflg = 0;
145 	uio->uio_resid = BIO_BI_SIZE(bio);
146 	uio->uio_skip = BIO_BI_SKIP(bio);
147 }
148 
149 #if defined(HAVE_VFS_IOV_ITER)
150 static inline void
uio_iov_iter_init(uio_t * uio,struct iov_iter * iter,offset_t offset,ssize_t resid,size_t skip)151 uio_iov_iter_init(uio_t *uio, struct iov_iter *iter, offset_t offset,
152     ssize_t resid, size_t skip)
153 {
154 	uio->uio_iter = iter;
155 	uio->uio_iovcnt = iter->nr_segs;
156 	uio->uio_loffset = offset;
157 	uio->uio_segflg = UIO_ITER;
158 	uio->uio_fault_disable = B_FALSE;
159 	uio->uio_fmode = 0;
160 	uio->uio_extflg = 0;
161 	uio->uio_resid = resid;
162 	uio->uio_skip = skip;
163 }
164 #endif
165 
166 #endif /* SPL_UIO_H */
167