FreeBSD/Linux Kernel Cross Reference
sys/arm/arm/mem.c
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 * 4. Neither the name of the University nor the names of its contributors
20 * may be used to endorse or promote products derived from this software
21 * without specific prior written permission.
22 *
23 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
24 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
25 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
26 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
27 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
28 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
29 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
30 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
31 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
32 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
33 * SUCH DAMAGE.
34 *
35 * from: Utah $Hdr: mem.c 1.13 89/10/08$
36 * from: @(#)mem.c 7.2 (Berkeley) 5/9/91
37 */
38
39 #include <sys/cdefs.h>
40 __FBSDID("$FreeBSD$");
41
42 /*
43 * Memory special file
44 */
45
46 #include <sys/param.h>
47 #include <sys/conf.h>
48 #include <sys/fcntl.h>
49 #include <sys/ioccom.h>
50 #include <sys/kernel.h>
51 #include <sys/lock.h>
52 #include <sys/malloc.h>
53 #include <sys/memrange.h>
54 #include <sys/module.h>
55 #include <sys/mutex.h>
56 #include <sys/proc.h>
57 #include <sys/signalvar.h>
58 #include <sys/sx.h>
59 #include <sys/systm.h>
60 #include <sys/uio.h>
61
62 #include <vm/vm.h>
63 #include <vm/pmap.h>
64 #include <vm/vm_extern.h>
65
66 #include <machine/memdev.h>
67 #include <machine/vmparam.h>
68
69 /*
70 * Used in /dev/mem drivers and elsewhere
71 */
72 MALLOC_DEFINE(M_MEMDESC, "memdesc", "memory range descriptors");
73
74 struct mem_range_softc mem_range_softc;
75
76 static struct sx tmppt_lock;
77 SX_SYSINIT(tmppt, &tmppt_lock, "mem4map");
78
79 /* ARGSUSED */
80 int
81 memrw(struct cdev *dev, struct uio *uio, int flags)
82 {
83 int o;
84 u_int c = 0, v;
85 struct iovec *iov;
86 int error = 0;
87 vm_offset_t addr, eaddr;
88
89 while (uio->uio_resid > 0 && error == 0) {
90 iov = uio->uio_iov;
91 if (iov->iov_len == 0) {
92 uio->uio_iov++;
93 uio->uio_iovcnt--;
94 if (uio->uio_iovcnt < 0)
95 panic("memrw");
96 continue;
97 }
98 if (dev2unit(dev) == CDEV_MINOR_MEM) {
99 int i;
100 int address_valid = 0;
101
102 v = uio->uio_offset;
103 v &= ~PAGE_MASK;
104 for (i = 0; dump_avail[i] || dump_avail[i + 1];
105 i += 2) {
106 if (v >= dump_avail[i] &&
107 v < dump_avail[i + 1]) {
108 address_valid = 1;
109 break;
110 }
111 }
112 if (!address_valid)
113 return (EINVAL);
114 sx_xlock(&tmppt_lock);
115 pmap_kenter((vm_offset_t)_tmppt, v);
116 o = (int)uio->uio_offset & PAGE_MASK;
117 c = (u_int)(PAGE_SIZE - ((int)iov->iov_base & PAGE_MASK));
118 c = min(c, (u_int)(PAGE_SIZE - o));
119 c = min(c, (u_int)iov->iov_len);
120 error = uiomove((caddr_t)&_tmppt[o], (int)c, uio);
121 pmap_qremove((vm_offset_t)_tmppt, 1);
122 sx_xunlock(&tmppt_lock);
123 continue;
124 }
125 else if (dev2unit(dev) == CDEV_MINOR_KMEM) {
126 c = iov->iov_len;
127
128 /*
129 * Make sure that all of the pages are currently
130 * resident so that we don't create any zero-fill
131 * pages.
132 */
133 addr = trunc_page(uio->uio_offset);
134 eaddr = round_page(uio->uio_offset + c);
135
136 for (; addr < eaddr; addr += PAGE_SIZE)
137 if (pmap_extract(kernel_pmap, addr) == 0)
138 return (EFAULT);
139 if (!kernacc((caddr_t)(int)uio->uio_offset, c,
140 uio->uio_rw == UIO_READ ?
141 VM_PROT_READ : VM_PROT_WRITE))
142 return (EFAULT);
143 error = uiomove((caddr_t)(int)uio->uio_offset, (int)c, uio);
144 continue;
145 }
146 /* else panic! */
147 }
148 return (error);
149 }
150
151 /*
152 * allow user processes to MMAP some memory sections
153 * instead of going through read/write
154 */
155 /* ARGSUSED */
156
157 int
158 memmmap(struct cdev *dev, vm_ooffset_t offset, vm_paddr_t *paddr,
159 int prot __unused, vm_memattr_t *memattr __unused)
160 {
161 if (dev2unit(dev) == CDEV_MINOR_MEM)
162 *paddr = offset;
163 else if (dev2unit(dev) == CDEV_MINOR_KMEM)
164 *paddr = vtophys(offset);
165 /* else panic! */
166 return (0);
167 }
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