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1.1 nbrk 1: /* $OpenBSD: mem.c,v 1.6 2007/01/15 23:19:05 jsg Exp $ */
2: /*
3: * Copyright (c) 1988 University of Utah.
4: * Copyright (c) 1982, 1986, 1990, 1993
5: * The Regents of the University of California. All rights reserved.
6: *
7: * This code is derived from software contributed to Berkeley by
8: * the Systems Programming Group of the University of Utah Computer
9: * Science Department.
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: * @(#)mem.c 8.3 (Berkeley) 1/12/94
40: */
41:
42: /*
43: * Memory special file
44: */
45:
46: #include <sys/param.h>
47: #include <sys/buf.h>
48: #include <sys/systm.h>
49: #include <sys/uio.h>
50: #include <sys/ioccom.h>
51: #include <sys/malloc.h>
52: #include <sys/memrange.h>
53: #include <sys/proc.h>
54: #include <sys/fcntl.h>
55:
56: #include <machine/cpu.h>
57: #include <machine/conf.h>
58:
59: #include <uvm/uvm_extern.h>
60:
61: caddr_t zeropage;
62: extern int start, end, etext;
63:
64: /* open counter for aperture */
65: #ifdef APERTURE
66: static int ap_open_count = 0;
67: extern int allowaperture;
68:
69: #define VGA_START 0xA0000
70: #define BIOS_END 0xFFFFF
71: #endif
72:
73: /*ARGSUSED*/
74: int
75: mmopen(dev_t dev, int flag, int mode, struct proc *p)
76: {
77: switch (minor(dev)) {
78: case 0:
79: case 1:
80: case 2:
81: case 12:
82: break;
83: #ifdef APERTURE
84: case 4:
85: if (suser(p, 0) != 0 || !allowaperture)
86: return (EPERM);
87:
88: /* authorize only one simultaneous open() */
89: if (ap_open_count > 0)
90: return(EPERM);
91: ap_open_count++;
92: break;
93: #endif
94: default:
95: return (ENXIO);
96: }
97: return (0);
98: }
99:
100: /*ARGSUSED*/
101: int
102: mmclose(dev_t dev, int flag, int mode, struct proc *p)
103: {
104: #ifdef APERTURE
105: if (minor(dev) == 4)
106: ap_open_count--;
107: #endif
108: return (0);
109: }
110:
111: /*ARGSUSED*/
112: int
113: mmrw(dev_t dev, struct uio *uio, int flags)
114: {
115: extern vaddr_t kern_end;
116: vaddr_t v;
117: int c;
118: struct iovec *iov;
119: int error = 0;
120:
121: while (uio->uio_resid > 0 && error == 0) {
122: iov = uio->uio_iov;
123: if (iov->iov_len == 0) {
124: uio->uio_iov++;
125: uio->uio_iovcnt--;
126: if (uio->uio_iovcnt < 0)
127: panic("mmrw");
128: continue;
129: }
130: switch (minor(dev)) {
131:
132: /* minor device 0 is physical memory */
133: case 0:
134: v = PMAP_DIRECT_MAP(uio->uio_offset);
135: error = uiomove((caddr_t)v, uio->uio_resid, uio);
136: continue;
137:
138: /* minor device 1 is kernel memory */
139: case 1:
140: v = uio->uio_offset;
141: c = min(iov->iov_len, MAXPHYS);
142: if (v >= (vaddr_t)&start && v < kern_end) {
143: if (v < (vaddr_t)&etext &&
144: uio->uio_rw == UIO_WRITE)
145: return EFAULT;
146: } else if ((!uvm_kernacc((caddr_t)v, c,
147: uio->uio_rw == UIO_READ ? B_READ : B_WRITE)) &&
148: (v < PMAP_DIRECT_BASE && v > PMAP_DIRECT_END))
149: return (EFAULT);
150: error = uiomove((caddr_t)v, c, uio);
151: continue;
152:
153: /* minor device 2 is EOF/RATHOLE */
154: case 2:
155: if (uio->uio_rw == UIO_WRITE)
156: uio->uio_resid = 0;
157: return (0);
158:
159: /* minor device 12 (/dev/zero) is source of nulls on read, rathole on write */
160: case 12:
161: if (uio->uio_rw == UIO_WRITE) {
162: c = iov->iov_len;
163: break;
164: }
165: if (zeropage == NULL) {
166: zeropage = (caddr_t)
167: malloc(PAGE_SIZE, M_TEMP, M_WAITOK);
168: bzero(zeropage, PAGE_SIZE);
169: }
170: c = min(iov->iov_len, PAGE_SIZE);
171: error = uiomove(zeropage, c, uio);
172: continue;
173:
174: default:
175: return (ENXIO);
176: }
177: iov->iov_base += c;
178: iov->iov_len -= c;
179: uio->uio_offset += c;
180: uio->uio_resid -= c;
181: }
182:
183: return (error);
184: }
185:
186: paddr_t
187: mmmmap(dev_t dev, off_t off, int prot)
188: {
189: struct proc *p = curproc; /* XXX */
190:
191: switch (minor(dev)) {
192: /* minor device 0 is physical memory */
193: case 0:
194: if ((paddr_t)off > (paddr_t)ctob(physmem) && suser(p, 0) != 0)
195: return -1;
196: return atop(off);
197:
198: #ifdef APERTURE
199: /* minor device 4 is aperture driver */
200: case 4:
201: switch (allowaperture) {
202: case 1:
203: /* Allow mapping of the VGA framebuffer & BIOS only */
204: if ((off >= VGA_START && off <= BIOS_END) ||
205: (unsigned)off > (unsigned)ctob(physmem))
206: return atop(off);
207: else
208: return -1;
209: case 2:
210: /* Allow mapping of the whole 1st megabyte
211: for x86emu */
212: if (off <= BIOS_END ||
213: (unsigned)off > (unsigned)ctob(physmem))
214: return atop(off);
215: else
216: return -1;
217: default:
218: return -1;
219: }
220:
221: #endif
222: default:
223: return -1;
224: }
225: }
226:
227: int
228: mmioctl(dev_t dev, u_long cmd, caddr_t data, int flags, struct proc *p)
229: {
230: return (ENODEV);
231: }
232: