1 /* $NetBSD: mem.c,v 1.31 1996/05/03 19:42:19 christos Exp $ */
2 /* $OpenBSD: mem.c,v 1.32 2006/12/29 13:04:37 pedro Exp $ */
3 /*
4 * Copyright (c) 1988 University of Utah.
5 * Copyright (c) 1982, 1986, 1990, 1993
6 * The Regents of the University of California. All rights reserved.
7 *
8 * This code is derived from software contributed to Berkeley by
9 * the Systems Programming Group of the University of Utah Computer
10 * Science Department.
11 *
12 * Redistribution and use in source and binary forms, with or without
13 * modification, are permitted provided that the following conditions
14 * are met:
15 * 1. Redistributions of source code must retain the above copyright
16 * notice, this list of conditions and the following disclaimer.
17 * 2. Redistributions in binary form must reproduce the above copyright
18 * notice, this list of conditions and the following disclaimer in the
19 * documentation and/or other materials provided with the distribution.
20 * 3. Neither the name of the University nor the names of its contributors
21 * may be used to endorse or promote products derived from this software
22 * without specific prior written permission.
23 *
24 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
25 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
26 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
27 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
28 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
29 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
30 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
31 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
32 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
33 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
34 * SUCH DAMAGE.
35 *
36 * @(#)mem.c 8.3 (Berkeley) 1/12/94
37 */
38
39 /*
40 * Memory special file
41 */
42
43 #include <sys/param.h>
44 #include <sys/buf.h>
45 #include <sys/systm.h>
46 #include <sys/uio.h>
47 #include <sys/ioccom.h>
48 #include <sys/malloc.h>
49 #include <sys/memrange.h>
50 #include <sys/proc.h>
51 #include <sys/fcntl.h>
52
53 #include <machine/cpu.h>
54 #include <machine/conf.h>
55
56 #include <uvm/uvm_extern.h>
57
58 #include "mtrr.h"
59
60 extern char *vmmap; /* poor name! */
61 caddr_t zeropage;
62
63 /* open counter for aperture */
64 #ifdef APERTURE
65 static int ap_open_count = 0;
66 extern int allowaperture;
67
68 #define VGA_START 0xA0000
69 #define BIOS_END 0xFFFFF
70 #endif
71
72 #if NMTRR > 0
73 struct mem_range_softc mem_range_softc;
74 static int mem_ioctl(dev_t, u_long, caddr_t, int, struct proc *);
75 #endif
76
77 /*ARGSUSED*/
78 int
79 mmopen(dev_t dev, int flag, int mode, struct proc *p)
80 {
81
82 switch (minor(dev)) {
83 case 0:
84 case 1:
85 case 2:
86 case 12:
87 break;
88 #ifdef APERTURE
89 case 4:
90 if (suser(p, 0) != 0 || !allowaperture)
91 return (EPERM);
92
93 /* authorize only one simultaneous open() */
94 if (ap_open_count > 0)
95 return(EPERM);
96 ap_open_count++;
97 break;
98 #endif
99 default:
100 return (ENXIO);
101 }
102 return (0);
103 }
104
105 /*ARGSUSED*/
106 int
107 mmclose(dev_t dev, int flag, int mode, struct proc *p)
108 {
109 #ifdef APERTURE
110 if (minor(dev) == 4)
111 ap_open_count--;
112 #endif
113 return (0);
114 }
115
116 /*ARGSUSED*/
117 int
118 mmrw(dev_t dev, struct uio *uio, int flags)
119 {
120 vaddr_t o, v;
121 int c;
122 struct iovec *iov;
123 int error = 0;
124 static int physlock;
125
126 if (minor(dev) == 0) {
127 /* lock against other uses of shared vmmap */
128 while (physlock > 0) {
129 physlock++;
130 error = tsleep((caddr_t)&physlock, PZERO | PCATCH,
131 "mmrw", 0);
132 if (error)
133 return (error);
134 }
135 physlock = 1;
136 }
137 while (uio->uio_resid > 0 && error == 0) {
138 iov = uio->uio_iov;
139 if (iov->iov_len == 0) {
140 uio->uio_iov++;
141 uio->uio_iovcnt--;
142 if (uio->uio_iovcnt < 0)
143 panic("mmrw");
144 continue;
145 }
146 switch (minor(dev)) {
147
148 /* minor device 0 is physical memory */
149 case 0:
150 v = uio->uio_offset;
151 pmap_enter(pmap_kernel(), (vaddr_t)vmmap,
152 trunc_page(v), uio->uio_rw == UIO_READ ?
153 VM_PROT_READ : VM_PROT_WRITE, PMAP_WIRED);
154 pmap_update(pmap_kernel());
155 o = uio->uio_offset & PGOFSET;
156 c = min(uio->uio_resid, (int)(NBPG - o));
157 error = uiomove((caddr_t)vmmap + o, c, uio);
158 pmap_remove(pmap_kernel(), (vaddr_t)vmmap,
159 (vaddr_t)vmmap + NBPG);
160 pmap_update(pmap_kernel());
161 continue;
162
163 /* minor device 1 is kernel memory */
164 case 1:
165 v = uio->uio_offset;
166 c = min(iov->iov_len, MAXPHYS);
167 if (!uvm_kernacc((caddr_t)v, c,
168 uio->uio_rw == UIO_READ ? B_READ : B_WRITE))
169 return (EFAULT);
170 error = uiomove((caddr_t)v, c, uio);
171 continue;
172
173 /* minor device 2 is EOF/RATHOLE */
174 case 2:
175 if (uio->uio_rw == UIO_WRITE)
176 uio->uio_resid = 0;
177 return (0);
178
179 /* minor device 12 (/dev/zero) is source of nulls on read, rathole on write */
180 case 12:
181 if (uio->uio_rw == UIO_WRITE) {
182 c = iov->iov_len;
183 break;
184 }
185 if (zeropage == NULL) {
186 zeropage = (caddr_t)
187 malloc(PAGE_SIZE, M_TEMP, M_WAITOK);
188 bzero(zeropage, PAGE_SIZE);
189 }
190 c = min(iov->iov_len, PAGE_SIZE);
191 error = uiomove(zeropage, c, uio);
192 continue;
193
194 default:
195 return (ENXIO);
196 }
197 (char *)iov->iov_base += c;
198 iov->iov_len -= c;
199 uio->uio_offset += c;
200 uio->uio_resid -= c;
201 }
202 if (minor(dev) == 0) {
203 if (physlock > 1)
204 wakeup((caddr_t)&physlock);
205 physlock = 0;
206 }
207 return (error);
208 }
209
210 paddr_t
211 mmmmap(dev_t dev, off_t off, int prot)
212 {
213 struct proc *p = curproc; /* XXX */
214
215 switch (minor(dev)) {
216 /* minor device 0 is physical memory */
217 case 0:
218 if ((u_int)off > ctob(physmem) &&
219 suser(p, 0) != 0)
220 return -1;
221 return atop(off);
222
223 #ifdef APERTURE
224 /* minor device 4 is aperture driver */
225 case 4:
226 switch (allowaperture) {
227 case 1:
228 /* Allow mapping of the VGA framebuffer & BIOS only */
229 if ((off >= VGA_START && off <= BIOS_END) ||
230 (unsigned)off > (unsigned)ctob(physmem))
231 return atop(off);
232 else
233 return -1;
234 case 2:
235 /* Allow mapping of the whole 1st megabyte
236 for x86emu */
237 if (off <= BIOS_END ||
238 (unsigned)off > (unsigned)ctob(physmem))
239 return atop(off);
240 else
241 return -1;
242 default:
243 return -1;
244 }
245
246 #endif
247 default:
248 return -1;
249 }
250 }
251
252 int
253 mmioctl(dev_t dev, u_long cmd, caddr_t data, int flags, struct proc *p)
254 {
255 #if NMTRR > 0
256 switch (minor(dev)) {
257 case 0:
258 case 4:
259 return mem_ioctl(dev, cmd, data, flags, p);
260 }
261 #endif
262 return (ENODEV);
263 }
264
265 #if NMTRR > 0
266 /*
267 * Operations for changing memory attributes.
268 *
269 * This is basically just an ioctl shim for mem_range_attr_get
270 * and mem_range_attr_set.
271 */
272 static int
273 mem_ioctl(dev_t dev, u_long cmd, caddr_t data, int flags, struct proc *p)
274 {
275 int nd, error = 0;
276 struct mem_range_op *mo = (struct mem_range_op *)data;
277 struct mem_range_desc *md;
278
279 /* is this for us? */
280 if ((cmd != MEMRANGE_GET) &&
281 (cmd != MEMRANGE_SET))
282 return (ENOTTY);
283
284 /* any chance we can handle this? */
285 if (mem_range_softc.mr_op == NULL)
286 return (EOPNOTSUPP);
287
288 /* do we have any descriptors? */
289 if (mem_range_softc.mr_ndesc == 0)
290 return (ENXIO);
291
292 switch (cmd) {
293 case MEMRANGE_GET:
294 nd = imin(mo->mo_arg[0], mem_range_softc.mr_ndesc);
295 if (nd > 0) {
296 md = (struct mem_range_desc *)
297 malloc(nd * sizeof(struct mem_range_desc),
298 M_MEMDESC, M_WAITOK);
299 error = mem_range_attr_get(md, &nd);
300 if (!error)
301 error = copyout(md, mo->mo_desc,
302 nd * sizeof(struct mem_range_desc));
303 free(md, M_MEMDESC);
304 } else {
305 nd = mem_range_softc.mr_ndesc;
306 }
307 mo->mo_arg[0] = nd;
308 break;
309
310 case MEMRANGE_SET:
311 md = malloc(sizeof(struct mem_range_desc), M_MEMDESC, M_WAITOK);
312 error = copyin(mo->mo_desc, md, sizeof(struct mem_range_desc));
313 /* clamp description string */
314 md->mr_owner[sizeof(md->mr_owner) - 1] = 0;
315 if (error == 0)
316 error = mem_range_attr_set(md, &mo->mo_arg[0]);
317 free(md, M_MEMDESC);
318 break;
319 }
320 return (error);
321 }
322
323 /*
324 * Implementation-neutral, kernel-callable functions for manipulating
325 * memory range attributes.
326 */
327 int
328 mem_range_attr_get(struct mem_range_desc *mrd, int *arg)
329 {
330 /* can we handle this? */
331 if (mem_range_softc.mr_op == NULL)
332 return (EOPNOTSUPP);
333
334 if (*arg == 0) {
335 *arg = mem_range_softc.mr_ndesc;
336 } else {
337 bcopy(mem_range_softc.mr_desc, mrd, (*arg) * sizeof(struct mem_range_desc));
338 }
339 return (0);
340 }
341
342 int
343 mem_range_attr_set(struct mem_range_desc *mrd, int *arg)
344 {
345 /* can we handle this? */
346 if (mem_range_softc.mr_op == NULL)
347 return (EOPNOTSUPP);
348
349 return (mem_range_softc.mr_op->set(&mem_range_softc, mrd, arg));
350 }
351
352 #endif /* NMTRR > 0 */
353