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1 | /* |
2 | * Copyright (c) 1988 University of Utah. | |
3 | * Copyright (c) 1982, 1986, 1990 The Regents of the University of California. | |
4 | * All rights reserved. | |
5 | * | |
6 | * This code is derived from software contributed to Berkeley by | |
7 | * the Systems Programming Group of the University of Utah Computer | |
8 | * Science Department. | |
9 | * | |
10 | * %sccs.include.redist.c% | |
11 | * | |
12 | * from: Utah $Hdr: mem.c 1.13 89/10/08$ | |
13 | * | |
b28b3a13 | 14 | * @(#)mem.c 7.3 (Berkeley) %G% |
88a7e859 KM |
15 | */ |
16 | ||
17 | /* | |
18 | * Memory special file | |
19 | */ | |
20 | ||
b28b3a13 KB |
21 | #include "sys/param.h" |
22 | #include "sys/user.h" | |
23 | #include "sys/conf.h" | |
24 | #include "sys/buf.h" | |
25 | #include "sys/systm.h" | |
26 | #include "sys/cmap.h" | |
27 | #include "sys/uio.h" | |
28 | #include "sys/malloc.h" | |
88a7e859 | 29 | |
b28b3a13 | 30 | #include "../include/cpu.h" |
88a7e859 | 31 | |
b28b3a13 KB |
32 | #include "vm/vm_param.h" |
33 | #include "vm/pmap.h" | |
34 | #include "vm/vm_prot.h" | |
22d09b27 | 35 | |
88a7e859 KM |
36 | /*ARGSUSED*/ |
37 | mmrw(dev, uio, flags) | |
38 | dev_t dev; | |
39 | struct uio *uio; | |
40 | int flags; | |
41 | { | |
42 | register int o; | |
43 | register u_int c, v; | |
44 | register struct iovec *iov; | |
45 | int error = 0; | |
46 | caddr_t zbuf = NULL; | |
47 | extern u_int lowram; | |
48 | ||
49 | while (uio->uio_resid > 0 && error == 0) { | |
50 | iov = uio->uio_iov; | |
51 | if (iov->iov_len == 0) { | |
52 | uio->uio_iov++; | |
53 | uio->uio_iovcnt--; | |
54 | if (uio->uio_iovcnt < 0) | |
55 | panic("mmrw"); | |
56 | continue; | |
57 | } | |
58 | switch (minor(dev)) { | |
59 | ||
60 | /* minor device 0 is physical memory */ | |
61 | case 0: | |
62 | v = uio->uio_offset; | |
63 | #ifndef DEBUG | |
64 | /* allow reads only in RAM (except for DEBUG) */ | |
65 | if (v >= 0xFFFFFFFC || v < lowram) | |
22d09b27 | 66 | return (EFAULT); |
88a7e859 | 67 | #endif |
22d09b27 KM |
68 | pmap_enter(pmap_kernel(), vmmap, v, |
69 | uio->uio_rw == UIO_READ ? VM_PROT_READ : VM_PROT_WRITE, | |
70 | TRUE); | |
88a7e859 KM |
71 | o = (int)uio->uio_offset & PGOFSET; |
72 | c = (u_int)(NBPG - ((int)iov->iov_base & PGOFSET)); | |
73 | c = MIN(c, (u_int)(NBPG - o)); | |
74 | c = MIN(c, (u_int)iov->iov_len); | |
75 | error = uiomove((caddr_t)&vmmap[o], (int)c, uio); | |
22d09b27 | 76 | pmap_remove(pmap_kernel(), vmmap, &vmmap[NBPG]); |
88a7e859 KM |
77 | continue; |
78 | ||
79 | /* minor device 1 is kernel memory */ | |
80 | case 1: | |
22d09b27 | 81 | c = MIN(iov->iov_len, MAXPHYS); |
88a7e859 KM |
82 | if (!kernacc((caddr_t)uio->uio_offset, c, |
83 | uio->uio_rw == UIO_READ ? B_READ : B_WRITE)) | |
22d09b27 | 84 | return (EFAULT); |
88a7e859 KM |
85 | error = uiomove((caddr_t)uio->uio_offset, (int)c, uio); |
86 | continue; | |
87 | ||
88 | /* minor device 2 is EOF/RATHOLE */ | |
89 | case 2: | |
90 | if (uio->uio_rw == UIO_READ) | |
91 | return (0); | |
92 | c = iov->iov_len; | |
93 | break; | |
94 | ||
95 | /* minor device 12 (/dev/zero) is source of nulls on read, rathole on write */ | |
96 | case 12: | |
97 | if (uio->uio_rw == UIO_WRITE) { | |
98 | c = iov->iov_len; | |
99 | break; | |
100 | } | |
101 | if (zbuf == NULL) { | |
102 | zbuf = (caddr_t) | |
103 | malloc(CLBYTES, M_TEMP, M_WAITOK); | |
104 | bzero(zbuf, CLBYTES); | |
105 | } | |
106 | c = MIN(iov->iov_len, CLBYTES); | |
107 | error = uiomove(zbuf, (int)c, uio); | |
108 | continue; | |
109 | ||
110 | default: | |
111 | return (ENXIO); | |
112 | } | |
113 | if (error) | |
114 | break; | |
115 | iov->iov_base += c; | |
116 | iov->iov_len -= c; | |
117 | uio->uio_offset += c; | |
118 | uio->uio_resid -= c; | |
119 | } | |
120 | if (zbuf) | |
121 | free(zbuf, M_TEMP); | |
122 | return (error); | |
88a7e859 | 123 | } |