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, and code derived from software contributed to
9 * Berkeley by William Jolitz.
10 *
11 * Redistribution and use in source and binary forms, with or without
12 * modification, are permitted provided that the following conditions
13 * are met:
14 * 1. Redistributions of source code must retain the above copyright
15 * notice, this list of conditions and the following disclaimer.
16 * 2. Redistributions in binary form must reproduce the above copyright
17 * notice, this list of conditions and the following disclaimer in the
18 * documentation and/or other materials provided with the distribution.
19 * 3. All advertising materials mentioning features or use of this software
20 * must display the following acknowledgement:
21 * This product includes software developed by the University of
22 * California, Berkeley and its contributors.
23 * 4. Neither the name of the University nor the names of its contributors
24 * may be used to endorse or promote products derived from this software
25 * without specific prior written permission.
26 *
27 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
28 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
29 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
30 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
31 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
32 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
33 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
34 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
35 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
36 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
37 * SUCH DAMAGE.
38 *
39 * $Id: mem.c,v 1.3 94/07/07 21:05:52 bill Exp Locker: bill $
40 */
41
42 /*
43 * Memory special file
44 */
45 static char *mem_config =
46 "mem 2. # mem device /dev/mem $Revision: 1.3 $";
47
48 #include "sys/param.h"
49 #include "sys/errno.h"
50 #include "sys/mman.h"
51 #include "malloc.h"
52 #include "uio.h"
53 #include "modconfig.h"
54 #include "prototypes.h"
55
56 #include "machine/cpu.h"
57
58 #include "vm.h"
59 #include "vmspace.h"
60
61 extern char *vmmap; /* poor name! */
62
63 int
mmrw(dev_t dev,struct uio * uio,int flags)64 mmrw(dev_t dev, struct uio *uio, int flags)
65 {
66 register int o;
67 register u_int c, v;
68 register struct iovec *iov;
69 int error = 0;
70 caddr_t zbuf = NULL;
71
72 while (uio->uio_resid > 0 && error == 0) {
73 iov = uio->uio_iov;
74 if (iov->iov_len == 0) {
75 uio->uio_iov++;
76 uio->uio_iovcnt--;
77 if (uio->uio_iovcnt < 0)
78 panic("mmrw");
79 continue;
80 }
81 switch (minor(dev)) {
82
83 /* minor device 0 is physical memory */
84 case 0:
85 v = uio->uio_offset;
86 pmap_enter(pmap_kernel(), (vm_offset_t) vmmap, v,
87 uio->uio_rw == UIO_READ ? VM_PROT_READ : VM_PROT_WRITE,
88 TRUE, AM_NONE);
89 o = (int)uio->uio_offset & PGOFSET;
90 c = (u_int)(NBPG - ((int)iov->iov_base & PGOFSET));
91 c = min(c, (u_int)(NBPG - o));
92 c = min(c, (u_int)iov->iov_len);
93 error = uiomove((caddr_t)&vmmap[o], (int)c, uio);
94 pmap_remove(pmap_kernel(), (vm_offset_t) vmmap, (vm_offset_t)vmmap+NBPG);
95 continue;
96
97 /* minor device 1 is kernel memory */
98 case 1:
99 c = iov->iov_len;
100 if (!vmspace_access(&kernspace, (caddr_t)uio->uio_offset, c,
101 uio->uio_rw == UIO_READ ? PROT_READ : PROT_WRITE))
102 return(EFAULT);
103 error = uiomove((caddr_t)uio->uio_offset, (int)c, uio);
104 continue;
105
106 /* minor device 2 is EOF/RATHOLE */
107 case 2:
108 if (uio->uio_rw == UIO_READ)
109 return (0);
110 c = iov->iov_len;
111 break;
112
113 /* minor device 12 (/dev/zero) is source of nulls on read, rathole on write */
114 case 12:
115 if (uio->uio_rw == UIO_WRITE) {
116 c = iov->iov_len;
117 break;
118 }
119 if (zbuf == NULL) {
120 zbuf = (caddr_t)
121 malloc(CLBYTES, M_TEMP, M_WAITOK);
122 memset(zbuf, 0, CLBYTES);
123 }
124 c = min(iov->iov_len, CLBYTES);
125 error = uiomove(zbuf, (int)c, uio);
126 continue;
127
128 #ifdef notyet
129 #ifdef i386
130 /* 386 I/O address space (/dev/ioport[bwl]) is a read/write access to seperate
131 i/o device address bus, different than memory bus. Semantics here are
132 very different than ordinary read/write, as if iov_len is a multiple
133 an implied string move from a single port will be done. Note that lseek
134 must be used to set the port number reliably. */
135 case 14:
136 if (iov->iov_len == 1) {
137 u_char tmp;
138 tmp = inb(uio->uio_offset);
139 error = uiomove (&tmp, iov->iov_len, uio);
140 } else {
141 if (!useracc((caddr_t)iov->iov_base,
142 iov->iov_len, uio->uio_rw))
143 return (EFAULT);
144 insb(uio->uio_offset, iov->iov_base,
145 iov->iov_len);
146 }
147 break;
148 case 15:
149 if (iov->iov_len == sizeof (short)) {
150 u_short tmp;
151 tmp = inw(uio->uio_offset);
152 error = uiomove (&tmp, iov->iov_len, uio);
153 } else {
154 if (!useracc((caddr_t)iov->iov_base,
155 iov->iov_len, uio->uio_rw))
156 return (EFAULT);
157 insw(uio->uio_offset, iov->iov_base,
158 iov->iov_len/ sizeof (short));
159 }
160 break;
161 case 16:
162 if (iov->iov_len == sizeof (long)) {
163 u_long tmp;
164 tmp = inl(uio->uio_offset);
165 error = uiomove (&tmp, iov->iov_len, uio);
166 } else {
167 if (!useracc((caddr_t)iov->iov_base,
168 iov->iov_len, uio->uio_rw))
169 return (EFAULT);
170 insl(uio->uio_offset, iov->iov_base,
171 iov->iov_len/ sizeof (long));
172 }
173 break;
174 #endif
175 #endif
176
177 default:
178 return (ENXIO);
179 }
180 if (error)
181 break;
182 iov->iov_base += c;
183 iov->iov_len -= c;
184 uio->uio_offset += c;
185 uio->uio_resid -= c;
186 }
187 if (zbuf)
188 free(zbuf, M_TEMP);
189 return (error);
190 }
191
192 /*
193 * XXX experimental
194 * (there is no way for dynamicly remapped regions in the kernel
195 * to shoot down mmap aliases to the kernel pages, as the association
196 * is busted by the mapping -wfj)
197 */
198 int
mmmmap(dev_t dev,int offset,int nprot)199 mmmmap(dev_t dev, int offset, int nprot)
200 {
201
202 switch (minor(dev)) {
203
204 case 0:
205 break;
206 case 1:
207 /* is it in kernel map? */
208 if (!vmspace_access(&kernspace, (caddr_t)offset, NBPG, nprot))
209 return(-1);
210 /* what physical address are we at? */
211 offset = (int) pmap_extract(pmap_kernel(),
212 (vm_offset_t) offset);
213 /* XXX pmap_extract should return -1, not 0 for non-existant */
214 /* if (offset == 0)
215 return (-1); */
216 break;
217 default:
218 return (-1);
219 }
220 return i386_btop(offset); /* XXX */
221 }
222
223 static struct devif mem_devif =
224 {
225 {0}, -1, -2, 0, 0, 0, 0, 0, 0,
226 0, 0, 0, mmrw, mmrw, 0, 0,
227 0, 0, 0, 0,
228 };
229
230 int mem_no;
231
DRIVER_MODCONFIG()232 DRIVER_MODCONFIG() {
233 char *cfg_string = mem_config;
234
235 /* configure device? */
236 if (devif_config(&cfg_string, &mem_devif) == 0)
237 return;
238
239 /* XXX trivial kernel dependancy: kernel knows driver state. */
240 mem_no = mem_devif.di_cmajor; /* should this be a di_flags bit? */
241 }
242