Merge from FreeBSD:
[dragonfly.git] / sys / kern / kern_physio.c
CommitLineData
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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 *
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19 * $FreeBSD: src/sys/kern/kern_physio.c,v 1.46.2.4 2003/11/14 09:51:47 simokawa Exp $
20 * $DragonFly: src/sys/kern/kern_physio.c,v 1.6 2004/02/09 21:51:28 hmp Exp $
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21 */
22
23#include <sys/param.h>
24#include <sys/systm.h>
25#include <sys/buf.h>
26#include <sys/conf.h>
27#include <sys/proc.h>
28#include <sys/uio.h>
335dda38 29#include <sys/device.h>
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30
31#include <vm/vm.h>
32#include <vm/vm_extern.h>
33
34static void
35physwakeup(struct buf *bp)
36{
37 wakeup((caddr_t) bp);
38}
39
40int
41physio(dev_t dev, struct uio *uio, int ioflag)
42{
43 int i;
44 int error;
45 int spl;
f366cb61 46 int chk_blockno;
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47 caddr_t sa;
48 off_t blockno;
49 u_int iolen;
50 struct buf *bp;
51
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52 /*
53 * NOTE: we no longer have to PHOLD() the process, because the
54 * kernel stack / uarea cannot be swapped, and when it can be in
55 * the future it will only happen if the process is sleeping on
56 * a particular address.
57 */
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58 bp = getpbuf(NULL);
59 sa = bp->b_data;
60 error = 0;
61
62 /* XXX: sanity check */
63 if(dev->si_iosize_max < PAGE_SIZE) {
64 printf("WARNING: %s si_iosize_max=%d, using DFLTPHYS.\n",
65 devtoname(dev), dev->si_iosize_max);
66 dev->si_iosize_max = DFLTPHYS;
67 }
68
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69 /* Don't check block number overflow for D_MEM */
70 if ((devsw(dev)->d_flags & D_TYPEMASK) == D_MEM)
71 chk_blockno = 0;
72 else
73 chk_blockno = 1;
74
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75 for (i = 0; i < uio->uio_iovcnt; i++) {
76 while (uio->uio_iov[i].iov_len) {
77 if (uio->uio_rw == UIO_READ)
78 bp->b_flags = B_PHYS | B_CALL | B_READ;
79 else
80 bp->b_flags = B_PHYS | B_CALL | B_WRITE;
81 bp->b_dev = dev;
82 bp->b_iodone = physwakeup;
83 bp->b_data = uio->uio_iov[i].iov_base;
84 bp->b_bcount = uio->uio_iov[i].iov_len;
85 bp->b_offset = uio->uio_offset;
86 bp->b_saveaddr = sa;
87
88 /* Don't exceed drivers iosize limit */
89 if (bp->b_bcount > dev->si_iosize_max)
90 bp->b_bcount = dev->si_iosize_max;
91
92 /*
93 * Make sure the pbuf can map the request
94 * XXX: The pbuf has kvasize = MAXPHYS so a request
95 * XXX: larger than MAXPHYS - PAGE_SIZE must be
96 * XXX: page aligned or it will be fragmented.
97 */
98 iolen = ((vm_offset_t) bp->b_data) & PAGE_MASK;
99 if ((bp->b_bcount + iolen) > bp->b_kvasize) {
100 bp->b_bcount = bp->b_kvasize;
101 if (iolen != 0)
102 bp->b_bcount -= PAGE_SIZE;
103 }
104 bp->b_bufsize = bp->b_bcount;
105
106 blockno = bp->b_offset >> DEV_BSHIFT;
f366cb61 107 if (chk_blockno && (daddr_t)blockno != blockno) {
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108 error = EINVAL; /* blockno overflow */
109 goto doerror;
110 }
111 bp->b_blkno = blockno;
112
113 if (uio->uio_segflg == UIO_USERSPACE)
114 if (vmapbuf(bp) < 0) {
115 error = EFAULT;
116 goto doerror;
117 }
118
119 BUF_STRATEGY(bp, 0);
120 spl = splbio();
121 while ((bp->b_flags & B_DONE) == 0)
377d4740 122 tsleep((caddr_t)bp, 0, "physstr", 0);
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123 splx(spl);
124
125 if (uio->uio_segflg == UIO_USERSPACE)
126 vunmapbuf(bp);
127 iolen = bp->b_bcount - bp->b_resid;
128 if (iolen == 0 && !(bp->b_flags & B_ERROR))
129 goto doerror; /* EOF */
130 uio->uio_iov[i].iov_len -= iolen;
131 uio->uio_iov[i].iov_base += iolen;
132 uio->uio_resid -= iolen;
133 uio->uio_offset += iolen;
134 if( bp->b_flags & B_ERROR) {
135 error = bp->b_error;
136 goto doerror;
137 }
138 }
139 }
140doerror:
141 relpbuf(bp, NULL);
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142 return (error);
143}