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: releng/6.1/sys/arm/arm/mem.c 137362 2004-11-07 23:01:36Z cognet $");
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/systm.h>
59 #include <sys/uio.h>
60
61 #include <vm/vm.h>
62 #include <vm/pmap.h>
63 #include <vm/vm_extern.h>
64
65 #include <machine/memdev.h>
66
67 /*
68 * Used in /dev/mem drivers and elsewhere
69 */
70 MALLOC_DEFINE(M_MEMDESC, "memdesc", "memory range descriptors");
71
72 /* ARGSUSED */
73 int
74 memrw(struct cdev *dev, struct uio *uio, int flags)
75 {
76 int o;
77 u_int c = 0, v;
78 struct iovec *iov;
79 int error = 0;
80 vm_offset_t addr, eaddr;
81
82 GIANT_REQUIRED;
83
84 while (uio->uio_resid > 0 && error == 0) {
85 iov = uio->uio_iov;
86 if (iov->iov_len == 0) {
87 uio->uio_iov++;
88 uio->uio_iovcnt--;
89 if (uio->uio_iovcnt < 0)
90 panic("memrw");
91 continue;
92 }
93 if (minor(dev) == CDEV_MINOR_MEM) {
94 v = uio->uio_offset;
95 v &= ~PAGE_MASK;
96 pmap_kenter((vm_offset_t)_tmppt, v);
97 o = (int)uio->uio_offset & PAGE_MASK;
98 c = (u_int)(PAGE_SIZE - ((int)iov->iov_base & PAGE_MASK));
99 c = min(c, (u_int)(PAGE_SIZE - o));
100 c = min(c, (u_int)iov->iov_len);
101 error = uiomove((caddr_t)&_tmppt[o], (int)c, uio);
102 pmap_qremove((vm_offset_t)_tmppt, 1);
103 continue;
104 }
105 else if (minor(dev) == CDEV_MINOR_KMEM) {
106 c = iov->iov_len;
107
108 /*
109 * Make sure that all of the pages are currently
110 * resident so that we don't create any zero-fill
111 * pages.
112 */
113 addr = trunc_page(uio->uio_offset);
114 eaddr = round_page(uio->uio_offset + c);
115
116 for (; addr < eaddr; addr += PAGE_SIZE)
117 if (pmap_extract(kernel_pmap, addr) == 0)
118 return (EFAULT);
119
120 if (!kernacc((caddr_t)(int)uio->uio_offset, c,
121 uio->uio_rw == UIO_READ ?
122 VM_PROT_READ : VM_PROT_WRITE))
123 return (EFAULT);
124 error = uiomove((caddr_t)(int)uio->uio_offset, (int)c, uio);
125 continue;
126 }
127 /* else panic! */
128 }
129 return (error);
130 }
131
132 /*
133 * allow user processes to MMAP some memory sections
134 * instead of going through read/write
135 */
136 /* ARGSUSED */
137
138 int
139 memmmap(struct cdev *dev, vm_offset_t offset, vm_paddr_t *paddr,
140 int prot __unused)
141 {
142 if (minor(dev) == CDEV_MINOR_MEM)
143 *paddr = offset;
144 else if (minor(dev) == CDEV_MINOR_KMEM)
145 *paddr = vtophys(offset);
146 /* else panic! */
147 return (0);
148 }
149
150 void
151 dev_mem_md_init(void)
152 {
153 }
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