Commit | Line | Data |
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4bd1c0bf WN |
1 | /*- |
2 | * Copyright (c) 1990 The Regents of the University of California. | |
3 | * All rights reserved. | |
4 | * | |
5 | * This code is derived from software contributed to Berkeley by | |
6 | * William Jolitz. | |
7 | * | |
8 | * %sccs.include.noredist.c% | |
9 | * | |
ab214bc8 | 10 | * @(#)mem.c 5.3 (Berkeley) %G% |
4bd1c0bf WN |
11 | */ |
12 | ||
01ebe5de BJ |
13 | /* |
14 | * Memory special file | |
15 | */ | |
16 | ||
ab214bc8 BJ |
17 | #include "machine/pte.h" |
18 | ||
19 | #include "param.h" | |
20 | #include "dir.h" | |
21 | #include "user.h" | |
22 | #include "conf.h" | |
23 | #include "buf.h" | |
24 | #include "systm.h" | |
25 | #include "vm.h" | |
26 | #include "cmap.h" | |
27 | #include "uio.h" | |
01ebe5de | 28 | |
01ebe5de BJ |
29 | mmread(dev, uio) |
30 | dev_t dev; | |
31 | struct uio *uio; | |
32 | { | |
33 | ||
34 | return (mmrw(dev, uio, UIO_READ)); | |
35 | } | |
36 | ||
37 | mmwrite(dev, uio) | |
38 | dev_t dev; | |
39 | struct uio *uio; | |
40 | { | |
41 | ||
42 | return (mmrw(dev, uio, UIO_WRITE)); | |
43 | } | |
44 | ||
45 | mmrw(dev, uio, rw) | |
46 | dev_t dev; | |
47 | struct uio *uio; | |
48 | enum uio_rw rw; | |
49 | { | |
50 | register int o; | |
51 | register u_int c, v; | |
52 | register struct iovec *iov; | |
53 | int error = 0; | |
01ebe5de BJ |
54 | |
55 | ||
56 | while (uio->uio_resid > 0 && error == 0) { | |
57 | iov = uio->uio_iov; | |
58 | if (iov->iov_len == 0) { | |
59 | uio->uio_iov++; | |
60 | uio->uio_iovcnt--; | |
61 | if (uio->uio_iovcnt < 0) | |
62 | panic("mmrw"); | |
63 | continue; | |
64 | } | |
65 | switch (minor(dev)) { | |
66 | ||
67 | /* minor device 0 is physical memory */ | |
68 | case 0: | |
69 | v = btop(uio->uio_offset); | |
70 | if (v >= physmem) | |
71 | goto fault; | |
4bd1c0bf | 72 | *(int *)mmap = ctob(v) | PG_V | |
01ebe5de | 73 | (rw == UIO_READ ? PG_KR : PG_KW); |
4bd1c0bf | 74 | load_cr3(_cr3()); |
01ebe5de BJ |
75 | o = (int)uio->uio_offset & PGOFSET; |
76 | c = (u_int)(NBPG - ((int)iov->iov_base & PGOFSET)); | |
77 | c = MIN(c, (u_int)(NBPG - o)); | |
78 | c = MIN(c, (u_int)iov->iov_len); | |
79 | error = uiomove((caddr_t)&vmmap[o], (int)c, rw, uio); | |
80 | continue; | |
81 | ||
82 | /* minor device 1 is kernel memory */ | |
83 | case 1: | |
01ebe5de BJ |
84 | c = iov->iov_len; |
85 | if (!kernacc((caddr_t)uio->uio_offset, c, rw == UIO_READ ? B_READ : B_WRITE)) | |
86 | goto fault; | |
87 | error = uiomove((caddr_t)uio->uio_offset, (int)c, rw, uio); | |
88 | continue; | |
89 | ||
90 | /* minor device 2 is EOF/RATHOLE */ | |
91 | case 2: | |
92 | if (rw == UIO_READ) | |
93 | return (0); | |
94 | c = iov->iov_len; | |
95 | break; | |
96 | ||
01ebe5de BJ |
97 | } |
98 | if (error) | |
99 | break; | |
100 | iov->iov_base += c; | |
101 | iov->iov_len -= c; | |
102 | uio->uio_offset += c; | |
103 | uio->uio_resid -= c; | |
104 | } | |
105 | return (error); | |
106 | fault: | |
107 | return (EFAULT); | |
108 | } |