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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 | * |
d1f75794 | 7 | * @(#)kern_physio.c 7.25 (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> | |
d301d150 | 18 | |
edc76308 | 19 | #ifdef HPUXCOMPAT |
251f56ba | 20 | #include <sys/user.h> |
edc76308 MK |
21 | #endif |
22 | ||
251f56ba KB |
23 | static void freeswbuf __P((struct buf *)); |
24 | static struct buf *getswbuf __P((int)); | |
edc76308 | 25 | |
663dbc72 | 26 | /* |
d99a6abd KM |
27 | * This routine does device I/O for a user process. |
28 | * | |
4fa687fa | 29 | * If the user has the proper access privileges, the process is |
663dbc72 | 30 | * marked 'delayed unlock' and the pages involved in the I/O are |
d99a6abd | 31 | * faulted and locked. After the completion of the I/O, the pages |
663dbc72 BJ |
32 | * are unlocked. |
33 | */ | |
d6d7360b BJ |
34 | physio(strat, bp, dev, rw, mincnt, uio) |
35 | int (*strat)(); | |
36 | register struct buf *bp; | |
37 | dev_t dev; | |
38 | int rw; | |
c5648f55 | 39 | u_int (*mincnt)(); |
d6d7360b | 40 | struct uio *uio; |
663dbc72 | 41 | { |
a196746e | 42 | register struct iovec *iov; |
a9fcede9 | 43 | register int requested = 0, done = 0; |
8429d022 | 44 | register struct proc *p = curproc; |
663dbc72 | 45 | char *a; |
c5648f55 | 46 | int s, allocbuf = 0, error = 0; |
ec67a3ce MK |
47 | #ifdef SECSIZE |
48 | int bsize; | |
49 | struct partinfo dpart; | |
50 | #endif SECSIZE | |
663dbc72 | 51 | |
ec67a3ce MK |
52 | #ifdef SECSIZE |
53 | if ((unsigned)major(dev) < nchrdev && | |
54 | (*cdevsw[major(dev)].d_ioctl)(dev, DIOCGPART, (caddr_t)&dpart, | |
55 | FREAD) == 0) | |
56 | bsize = dpart.disklab->d_secsize; | |
57 | else | |
58 | bsize = DEV_BSIZE; | |
59 | #endif SECSIZE | |
60 | for (;;) { | |
61 | if (uio->uio_iovcnt == 0) | |
62 | return (0); | |
63 | iov = uio->uio_iov; | |
64 | if (useracc(iov->iov_base, (u_int)iov->iov_len, | |
65 | rw==B_READ? B_WRITE : B_READ) == NULL) | |
66 | return (EFAULT); | |
67 | s = splbio(); | |
68 | while (bp->b_flags&B_BUSY) { | |
69 | bp->b_flags |= B_WANTED; | |
70 | sleep((caddr_t)bp, PRIBIO+1); | |
71 | } | |
c5648f55 KB |
72 | if (!allocbuf) { /* only if sharing caller's buffer */ |
73 | s = splbio(); | |
74 | while (bp->b_flags&B_BUSY) { | |
75 | bp->b_flags |= B_WANTED; | |
76 | sleep((caddr_t)bp, PRIBIO+1); | |
77 | } | |
78 | splx(s); | |
79 | } | |
ec67a3ce MK |
80 | bp->b_error = 0; |
81 | bp->b_proc = u.u_procp; | |
82 | #ifdef SECSIZE | |
83 | bp->b_blksize = bsize; | |
84 | #endif SECSIZE | |
85 | bp->b_un.b_addr = iov->iov_base; | |
86 | while (iov->iov_len > 0) { | |
87 | bp->b_flags = B_BUSY | B_PHYS | rw; | |
88 | bp->b_dev = dev; | |
89 | #ifdef SECSIZE | |
90 | bp->b_blkno = uio->uio_offset / bsize; | |
91 | #else SECSIZE | |
92 | bp->b_blkno = btodb(uio->uio_offset); | |
93 | #endif SECSIZE | |
94 | bp->b_bcount = iov->iov_len; | |
95 | (*mincnt)(bp); | |
96 | c = bp->b_bcount; | |
97 | u.u_procp->p_flag |= SPHYSIO; | |
98 | vslock(a = bp->b_un.b_addr, c); | |
99 | physstrat(bp, strat, PRIBIO); | |
100 | (void) splbio(); | |
101 | vsunlock(a, c, rw); | |
102 | u.u_procp->p_flag &= ~SPHYSIO; | |
103 | if (bp->b_flags&B_WANTED) | |
104 | wakeup((caddr_t)bp); | |
105 | splx(s); | |
106 | c -= bp->b_resid; | |
107 | bp->b_un.b_addr += c; | |
108 | iov->iov_len -= c; | |
109 | uio->uio_resid -= c; | |
110 | uio->uio_offset += c; | |
111 | /* temp kludge for tape drives */ | |
112 | if (bp->b_resid || (bp->b_flags&B_ERROR)) | |
113 | break; | |
114 | } | |
115 | bp->b_flags &= ~(B_BUSY|B_WANTED|B_PHYS); | |
116 | error = geterror(bp); | |
ec67a3ce MK |
117 | if (bp->b_resid || error) |
118 | return (error); | |
119 | uio->uio_iov++; | |
120 | uio->uio_iovcnt--; | |
663dbc72 | 121 | } |
cd682858 KM |
122 | #if defined(hp300) |
123 | DCIU(); | |
124 | #endif | |
c5648f55 KB |
125 | if (allocbuf) |
126 | freeswbuf(bp); | |
127 | return (error); | |
663dbc72 BJ |
128 | } |
129 | ||
d99a6abd KM |
130 | /* |
131 | * Calculate the maximum size of I/O request that can be requested | |
132 | * in a single operation. This limit is necessary to prevent a single | |
133 | * process from being able to lock more than a fixed amount of memory | |
134 | * in the kernel. | |
135 | */ | |
c5648f55 | 136 | u_int |
663dbc72 | 137 | minphys(bp) |
d6d7360b | 138 | struct buf *bp; |
663dbc72 | 139 | { |
35a494b8 SL |
140 | if (bp->b_bcount > MAXPHYS) |
141 | bp->b_bcount = MAXPHYS; | |
663dbc72 | 142 | } |
c5648f55 | 143 | |
251f56ba | 144 | static struct buf * |
c5648f55 KB |
145 | getswbuf(prio) |
146 | int prio; | |
147 | { | |
148 | int s; | |
149 | struct buf *bp; | |
150 | ||
151 | s = splbio(); | |
152 | while (bswlist.av_forw == NULL) { | |
153 | bswlist.b_flags |= B_WANTED; | |
154 | sleep((caddr_t)&bswlist, prio); | |
155 | } | |
156 | bp = bswlist.av_forw; | |
157 | bswlist.av_forw = bp->av_forw; | |
158 | splx(s); | |
159 | return (bp); | |
160 | } | |
161 | ||
251f56ba | 162 | static void |
c5648f55 KB |
163 | freeswbuf(bp) |
164 | struct buf *bp; | |
165 | { | |
166 | int s; | |
167 | ||
168 | s = splbio(); | |
169 | bp->av_forw = bswlist.av_forw; | |
170 | bswlist.av_forw = bp; | |
343a57bd KM |
171 | if (bp->b_vp) |
172 | brelvp(bp); | |
c5648f55 KB |
173 | if (bswlist.b_flags & B_WANTED) { |
174 | bswlist.b_flags &= ~B_WANTED; | |
175 | wakeup((caddr_t)&bswlist); | |
8429d022 | 176 | wakeup((caddr_t)pageproc); |
c5648f55 KB |
177 | } |
178 | splx(s); | |
179 | } | |
180 | ||
d99a6abd KM |
181 | /* |
182 | * Do a read on a device for a user process. | |
183 | */ | |
c5648f55 KB |
184 | rawread(dev, uio) |
185 | dev_t dev; | |
186 | struct uio *uio; | |
187 | { | |
188 | return (physio(cdevsw[major(dev)].d_strategy, (struct buf *)NULL, | |
189 | dev, B_READ, minphys, uio)); | |
190 | } | |
191 | ||
d99a6abd KM |
192 | /* |
193 | * Do a write on a device for a user process. | |
194 | */ | |
c5648f55 KB |
195 | rawwrite(dev, uio) |
196 | dev_t dev; | |
197 | struct uio *uio; | |
198 | { | |
199 | return (physio(cdevsw[major(dev)].d_strategy, (struct buf *)NULL, | |
200 | dev, B_WRITE, minphys, uio)); | |
201 | } |