1 /*
2 * Copyright (c) 1994 John S. Dyson
3 * All rights reserved.
4 *
5 * Redistribution and use in source and binary forms, with or without
6 * modification, are permitted provided that the following conditions
7 * are met:
8 * 1. Redistributions of source code must retain the above copyright
9 * notice immediately at the beginning of the file, without modification,
10 * this list of conditions, and the following disclaimer.
11 * 2. Redistributions in binary form must reproduce the above copyright
12 * notice, this list of conditions and the following disclaimer in the
13 * documentation and/or other materials provided with the distribution.
14 * 3. Absolutely no warranty of function or purpose is made by the author
15 * John S. Dyson.
16 * 4. Modifications may be freely made to this file if the above conditions
17 * are met.
18 *
19 * $FreeBSD$
20 */
21
22 #include <sys/param.h>
23 #include <sys/systm.h>
24 #include <sys/buf.h>
25 #include <sys/conf.h>
26 #include <sys/proc.h>
27 #include <sys/uio.h>
28
29 #include <vm/vm.h>
30 #include <vm/vm_extern.h>
31
32 static void
33 physwakeup(struct buf *bp)
34 {
35 wakeup((caddr_t) bp);
36 }
37
38 int
39 physio(dev_t dev, struct uio *uio, int ioflag)
40 {
41 int i;
42 int error;
43 int spl;
44 int chk_blockno;
45 caddr_t sa;
46 off_t blockno;
47 u_int iolen;
48 struct buf *bp;
49
50 /* Keep the process UPAGES from being swapped. XXX: why ? */
51 PHOLD(curproc);
52
53 bp = getpbuf(NULL);
54 sa = bp->b_data;
55 error = 0;
56
57 /* XXX: sanity check */
58 if(dev->si_iosize_max < PAGE_SIZE) {
59 printf("WARNING: %s si_iosize_max=%d, using DFLTPHYS.\n",
60 devtoname(dev), dev->si_iosize_max);
61 dev->si_iosize_max = DFLTPHYS;
62 }
63
64 /* Don't check block number overflow for D_MEM */
65 if ((devsw(dev)->d_flags & D_TYPEMASK) == D_MEM)
66 chk_blockno = 0;
67 else
68 chk_blockno = 1;
69
70 for (i = 0; i < uio->uio_iovcnt; i++) {
71 while (uio->uio_iov[i].iov_len) {
72 if (uio->uio_rw == UIO_READ)
73 bp->b_flags = B_PHYS | B_CALL | B_READ;
74 else
75 bp->b_flags = B_PHYS | B_CALL | B_WRITE;
76 bp->b_dev = dev;
77 bp->b_iodone = physwakeup;
78 bp->b_data = uio->uio_iov[i].iov_base;
79 bp->b_bcount = uio->uio_iov[i].iov_len;
80 bp->b_offset = uio->uio_offset;
81 bp->b_saveaddr = sa;
82
83 /* Don't exceed drivers iosize limit */
84 if (bp->b_bcount > dev->si_iosize_max)
85 bp->b_bcount = dev->si_iosize_max;
86
87 /*
88 * Make sure the pbuf can map the request
89 * XXX: The pbuf has kvasize = MAXPHYS so a request
90 * XXX: larger than MAXPHYS - PAGE_SIZE must be
91 * XXX: page aligned or it will be fragmented.
92 */
93 iolen = ((vm_offset_t) bp->b_data) & PAGE_MASK;
94 if ((bp->b_bcount + iolen) > bp->b_kvasize) {
95 bp->b_bcount = bp->b_kvasize;
96 if (iolen != 0)
97 bp->b_bcount -= PAGE_SIZE;
98 }
99 bp->b_bufsize = bp->b_bcount;
100
101 blockno = bp->b_offset >> DEV_BSHIFT;
102 if (chk_blockno && (daddr_t)blockno != blockno) {
103 error = EINVAL; /* blockno overflow */
104 goto doerror;
105 }
106 bp->b_blkno = blockno;
107
108 if (uio->uio_segflg == UIO_USERSPACE)
109 if (vmapbuf(bp) < 0) {
110 error = EFAULT;
111 goto doerror;
112 }
113
114 BUF_STRATEGY(bp, 0);
115 spl = splbio();
116 while ((bp->b_flags & B_DONE) == 0)
117 tsleep((caddr_t)bp, PRIBIO, "physstr", 0);
118 splx(spl);
119
120 if (uio->uio_segflg == UIO_USERSPACE)
121 vunmapbuf(bp);
122 iolen = bp->b_bcount - bp->b_resid;
123 if (iolen == 0 && !(bp->b_flags & B_ERROR))
124 goto doerror; /* EOF */
125 uio->uio_iov[i].iov_len -= iolen;
126 uio->uio_iov[i].iov_base += iolen;
127 uio->uio_resid -= iolen;
128 uio->uio_offset += iolen;
129 if( bp->b_flags & B_ERROR) {
130 error = bp->b_error;
131 goto doerror;
132 }
133 }
134 }
135 doerror:
136 relpbuf(bp, NULL);
137 PRELE(curproc);
138 return (error);
139 }
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