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1 | /*- |
2 | * Copyright (c) 1982, 1986, 1990 The Regents of the University of California. | |
3 | * All rights reserved. | |
4 | * | |
5 | * %sccs.include.proprietary.c% | |
da7c5cc6 | 6 | * |
4fa687fa | 7 | * @(#)kern_physio.c 7.23 (Berkeley) %G% |
da7c5cc6 | 8 | */ |
961945a8 | 9 | |
251f56ba KB |
10 | #include <sys/param.h> |
11 | #include <sys/systm.h> | |
12 | #include <sys/buf.h> | |
13 | #include <sys/conf.h> | |
14 | #include <sys/proc.h> | |
251f56ba KB |
15 | #include <sys/trace.h> |
16 | #include <sys/map.h> | |
17 | #include <sys/vnode.h> | |
18 | #include <sys/specdev.h> | |
d301d150 | 19 | |
edc76308 | 20 | #ifdef HPUXCOMPAT |
251f56ba | 21 | #include <sys/user.h> |
edc76308 MK |
22 | #endif |
23 | ||
251f56ba KB |
24 | static void freeswbuf __P((struct buf *)); |
25 | static struct buf *getswbuf __P((int)); | |
edc76308 | 26 | |
663dbc72 | 27 | /* |
d99a6abd KM |
28 | * This routine does device I/O for a user process. |
29 | * | |
4fa687fa | 30 | * If the user has the proper access privileges, the process is |
663dbc72 | 31 | * marked 'delayed unlock' and the pages involved in the I/O are |
d99a6abd | 32 | * faulted and locked. After the completion of the I/O, the pages |
663dbc72 BJ |
33 | * are unlocked. |
34 | */ | |
d6d7360b BJ |
35 | physio(strat, bp, dev, rw, mincnt, uio) |
36 | int (*strat)(); | |
37 | register struct buf *bp; | |
38 | dev_t dev; | |
39 | int rw; | |
c5648f55 | 40 | u_int (*mincnt)(); |
d6d7360b | 41 | struct uio *uio; |
663dbc72 | 42 | { |
a196746e | 43 | register struct iovec *iov; |
58c3cad7 | 44 | register int requested, done; |
8429d022 | 45 | register struct proc *p = curproc; |
663dbc72 | 46 | char *a; |
c5648f55 | 47 | int s, allocbuf = 0, error = 0; |
ec67a3ce MK |
48 | #ifdef SECSIZE |
49 | int bsize; | |
50 | struct partinfo dpart; | |
51 | #endif SECSIZE | |
663dbc72 | 52 | |
ec67a3ce MK |
53 | #ifdef SECSIZE |
54 | if ((unsigned)major(dev) < nchrdev && | |
55 | (*cdevsw[major(dev)].d_ioctl)(dev, DIOCGPART, (caddr_t)&dpart, | |
56 | FREAD) == 0) | |
57 | bsize = dpart.disklab->d_secsize; | |
58 | else | |
59 | bsize = DEV_BSIZE; | |
60 | #endif SECSIZE | |
61 | for (;;) { | |
62 | if (uio->uio_iovcnt == 0) | |
63 | return (0); | |
64 | iov = uio->uio_iov; | |
65 | if (useracc(iov->iov_base, (u_int)iov->iov_len, | |
66 | rw==B_READ? B_WRITE : B_READ) == NULL) | |
67 | return (EFAULT); | |
68 | s = splbio(); | |
69 | while (bp->b_flags&B_BUSY) { | |
70 | bp->b_flags |= B_WANTED; | |
71 | sleep((caddr_t)bp, PRIBIO+1); | |
72 | } | |
c5648f55 KB |
73 | if (!allocbuf) { /* only if sharing caller's buffer */ |
74 | s = splbio(); | |
75 | while (bp->b_flags&B_BUSY) { | |
76 | bp->b_flags |= B_WANTED; | |
77 | sleep((caddr_t)bp, PRIBIO+1); | |
78 | } | |
79 | splx(s); | |
80 | } | |
ec67a3ce MK |
81 | bp->b_error = 0; |
82 | bp->b_proc = u.u_procp; | |
83 | #ifdef SECSIZE | |
84 | bp->b_blksize = bsize; | |
85 | #endif SECSIZE | |
86 | bp->b_un.b_addr = iov->iov_base; | |
87 | while (iov->iov_len > 0) { | |
88 | bp->b_flags = B_BUSY | B_PHYS | rw; | |
89 | bp->b_dev = dev; | |
90 | #ifdef SECSIZE | |
91 | bp->b_blkno = uio->uio_offset / bsize; | |
92 | #else SECSIZE | |
93 | bp->b_blkno = btodb(uio->uio_offset); | |
94 | #endif SECSIZE | |
95 | bp->b_bcount = iov->iov_len; | |
96 | (*mincnt)(bp); | |
97 | c = bp->b_bcount; | |
98 | u.u_procp->p_flag |= SPHYSIO; | |
99 | vslock(a = bp->b_un.b_addr, c); | |
100 | physstrat(bp, strat, PRIBIO); | |
101 | (void) splbio(); | |
102 | vsunlock(a, c, rw); | |
103 | u.u_procp->p_flag &= ~SPHYSIO; | |
104 | if (bp->b_flags&B_WANTED) | |
105 | wakeup((caddr_t)bp); | |
106 | splx(s); | |
107 | c -= bp->b_resid; | |
108 | bp->b_un.b_addr += c; | |
109 | iov->iov_len -= c; | |
110 | uio->uio_resid -= c; | |
111 | uio->uio_offset += c; | |
112 | /* temp kludge for tape drives */ | |
113 | if (bp->b_resid || (bp->b_flags&B_ERROR)) | |
114 | break; | |
115 | } | |
116 | bp->b_flags &= ~(B_BUSY|B_WANTED|B_PHYS); | |
117 | error = geterror(bp); | |
ec67a3ce MK |
118 | if (bp->b_resid || error) |
119 | return (error); | |
120 | uio->uio_iov++; | |
121 | uio->uio_iovcnt--; | |
663dbc72 | 122 | } |
cd682858 KM |
123 | #if defined(hp300) |
124 | DCIU(); | |
125 | #endif | |
c5648f55 KB |
126 | if (allocbuf) |
127 | freeswbuf(bp); | |
128 | return (error); | |
663dbc72 BJ |
129 | } |
130 | ||
d99a6abd KM |
131 | /* |
132 | * Calculate the maximum size of I/O request that can be requested | |
133 | * in a single operation. This limit is necessary to prevent a single | |
134 | * process from being able to lock more than a fixed amount of memory | |
135 | * in the kernel. | |
136 | */ | |
c5648f55 | 137 | u_int |
663dbc72 | 138 | minphys(bp) |
d6d7360b | 139 | struct buf *bp; |
663dbc72 | 140 | { |
35a494b8 SL |
141 | if (bp->b_bcount > MAXPHYS) |
142 | bp->b_bcount = MAXPHYS; | |
663dbc72 | 143 | } |
c5648f55 | 144 | |
251f56ba | 145 | static struct buf * |
c5648f55 KB |
146 | getswbuf(prio) |
147 | int prio; | |
148 | { | |
149 | int s; | |
150 | struct buf *bp; | |
151 | ||
152 | s = splbio(); | |
153 | while (bswlist.av_forw == NULL) { | |
154 | bswlist.b_flags |= B_WANTED; | |
155 | sleep((caddr_t)&bswlist, prio); | |
156 | } | |
157 | bp = bswlist.av_forw; | |
158 | bswlist.av_forw = bp->av_forw; | |
159 | splx(s); | |
160 | return (bp); | |
161 | } | |
162 | ||
251f56ba | 163 | static void |
c5648f55 KB |
164 | freeswbuf(bp) |
165 | struct buf *bp; | |
166 | { | |
167 | int s; | |
168 | ||
169 | s = splbio(); | |
170 | bp->av_forw = bswlist.av_forw; | |
171 | bswlist.av_forw = bp; | |
343a57bd KM |
172 | if (bp->b_vp) |
173 | brelvp(bp); | |
c5648f55 KB |
174 | if (bswlist.b_flags & B_WANTED) { |
175 | bswlist.b_flags &= ~B_WANTED; | |
176 | wakeup((caddr_t)&bswlist); | |
8429d022 | 177 | wakeup((caddr_t)pageproc); |
c5648f55 KB |
178 | } |
179 | splx(s); | |
180 | } | |
181 | ||
d99a6abd KM |
182 | /* |
183 | * Do a read on a device for a user process. | |
184 | */ | |
c5648f55 KB |
185 | rawread(dev, uio) |
186 | dev_t dev; | |
187 | struct uio *uio; | |
188 | { | |
189 | return (physio(cdevsw[major(dev)].d_strategy, (struct buf *)NULL, | |
190 | dev, B_READ, minphys, uio)); | |
191 | } | |
192 | ||
d99a6abd KM |
193 | /* |
194 | * Do a write on a device for a user process. | |
195 | */ | |
c5648f55 KB |
196 | rawwrite(dev, uio) |
197 | dev_t dev; | |
198 | struct uio *uio; | |
199 | { | |
200 | return (physio(cdevsw[major(dev)].d_strategy, (struct buf *)NULL, | |
201 | dev, B_WRITE, minphys, uio)); | |
202 | } |