FreeBSD/Linux Kernel Cross Reference
sys/mips/mips/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/10.1/sys/mips/mips/mem.c 226459 2011-10-17 05:42:53Z jchandra $");
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/kernel.h>
50 #include <sys/lock.h>
51 #include <sys/malloc.h>
52 #include <sys/memrange.h>
53 #include <sys/module.h>
54 #include <sys/mutex.h>
55 #include <sys/proc.h>
56 #include <sys/msgbuf.h>
57 #include <sys/systm.h>
58 #include <sys/signalvar.h>
59 #include <sys/uio.h>
60
61 #include <machine/md_var.h>
62 #include <machine/vmparam.h>
63
64 #include <vm/vm.h>
65 #include <vm/pmap.h>
66 #include <vm/vm_extern.h>
67 #include <vm/vm_page.h>
68
69 #include <machine/memdev.h>
70
71 struct mem_range_softc mem_range_softc;
72
73 /* ARGSUSED */
74 int
75 memrw(struct cdev *dev, struct uio *uio, int flags)
76 {
77 struct iovec *iov;
78 int error = 0;
79 vm_offset_t va, eva, off, v;
80 vm_prot_t prot;
81 struct vm_page m;
82 vm_page_t marr;
83 vm_size_t cnt;
84
85 cnt = 0;
86 error = 0;
87
88 GIANT_REQUIRED;
89
90 pmap_page_init(&m);
91 while (uio->uio_resid > 0 && !error) {
92 iov = uio->uio_iov;
93 if (iov->iov_len == 0) {
94 uio->uio_iov++;
95 uio->uio_iovcnt--;
96 if (uio->uio_iovcnt < 0)
97 panic("memrw");
98 continue;
99 }
100 if (dev2unit(dev) == CDEV_MINOR_MEM) {
101 v = uio->uio_offset;
102
103 off = uio->uio_offset & PAGE_MASK;
104 cnt = PAGE_SIZE - ((vm_offset_t)iov->iov_base &
105 PAGE_MASK);
106 cnt = min(cnt, PAGE_SIZE - off);
107 cnt = min(cnt, iov->iov_len);
108
109 m.phys_addr = trunc_page(v);
110 marr = &m;
111 error = uiomove_fromphys(&marr, off, cnt, uio);
112 }
113 else if (dev2unit(dev) == CDEV_MINOR_KMEM) {
114 va = uio->uio_offset;
115
116 va = trunc_page(uio->uio_offset);
117 eva = round_page(uio->uio_offset
118 + iov->iov_len);
119
120 /*
121 * Make sure that all the pages are currently resident
122 * so that we don't create any zero-fill pages.
123 */
124 if (va >= VM_MIN_KERNEL_ADDRESS &&
125 eva <= VM_MAX_KERNEL_ADDRESS) {
126 for (; va < eva; va += PAGE_SIZE)
127 if (pmap_extract(kernel_pmap, va) == 0)
128 return (EFAULT);
129
130 prot = (uio->uio_rw == UIO_READ)
131 ? VM_PROT_READ : VM_PROT_WRITE;
132
133 va = uio->uio_offset;
134 if (kernacc((void *) va, iov->iov_len, prot)
135 == FALSE)
136 return (EFAULT);
137 }
138
139 va = uio->uio_offset;
140 error = uiomove((void *)va, iov->iov_len, uio);
141 continue;
142 }
143 }
144
145 return (error);
146 }
147
148 /*
149 * allow user processes to MMAP some memory sections
150 * instead of going through read/write
151 */
152 int
153 memmmap(struct cdev *dev, vm_ooffset_t offset, vm_paddr_t *paddr,
154 int prot, vm_memattr_t *memattr)
155 {
156 /*
157 * /dev/mem is the only one that makes sense through this
158 * interface. For /dev/kmem any physaddr we return here
159 * could be transient and hence incorrect or invalid at
160 * a later time.
161 */
162 if (dev2unit(dev) != CDEV_MINOR_MEM)
163 return (-1);
164
165 *paddr = offset;
166
167 return (0);
168 }
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