FreeBSD/Linux Kernel Cross Reference
sys/mips/mips/mem.c
1 /*-
2 * SPDX-License-Identifier: BSD-3-Clause
3 *
4 * Copyright (c) 1988 University of Utah.
5 * Copyright (c) 1982, 1986, 1990 The Regents of the University of California.
6 * 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, and code derived from software contributed to
11 * Berkeley by William Jolitz.
12 *
13 * Redistribution and use in source and binary forms, with or without
14 * modification, are permitted provided that the following conditions
15 * are met:
16 * 1. Redistributions of source code must retain the above copyright
17 * notice, this list of conditions and the following disclaimer.
18 * 2. Redistributions in binary form must reproduce the above copyright
19 * notice, this list of conditions and the following disclaimer in the
20 * documentation and/or other materials provided with the distribution.
21 * 3. Neither the name of the University nor the names of its contributors
22 * may be used to endorse or promote products derived from this software
23 * without specific prior written permission.
24 *
25 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
26 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
27 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
28 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
29 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
30 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
31 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
32 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
33 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
34 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
35 * SUCH DAMAGE.
36 *
37 * from: Utah $Hdr: mem.c 1.13 89/10/08$
38 * from: @(#)mem.c 7.2 (Berkeley) 5/9/91
39 */
40
41 #include <sys/cdefs.h>
42 __FBSDID("$FreeBSD$");
43
44 /*
45 * Memory special file
46 */
47
48 #include <sys/param.h>
49 #include <sys/conf.h>
50 #include <sys/fcntl.h>
51 #include <sys/kernel.h>
52 #include <sys/lock.h>
53 #include <sys/malloc.h>
54 #include <sys/memrange.h>
55 #include <sys/module.h>
56 #include <sys/mutex.h>
57 #include <sys/proc.h>
58 #include <sys/msgbuf.h>
59 #include <sys/systm.h>
60 #include <sys/signalvar.h>
61 #include <sys/uio.h>
62
63 #include <machine/md_var.h>
64 #include <machine/vmparam.h>
65
66 #include <vm/vm.h>
67 #include <vm/pmap.h>
68 #include <vm/vm_extern.h>
69 #include <vm/vm_page.h>
70
71 #include <machine/memdev.h>
72
73 struct mem_range_softc mem_range_softc;
74
75 /* ARGSUSED */
76 int
77 memrw(struct cdev *dev, struct uio *uio, int flags)
78 {
79 struct iovec *iov;
80 int error = 0;
81 vm_offset_t va, eva, off, v;
82 vm_prot_t prot;
83 struct vm_page m;
84 vm_page_t marr;
85 vm_size_t cnt;
86
87 cnt = 0;
88 error = 0;
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 if (dev2unit(dev) != CDEV_MINOR_MEM)
157 return (-1);
158
159 *paddr = offset;
160
161 return (0);
162 }
163
164 int
165 memioctl_md(struct cdev *dev __unused, u_long cmd __unused,
166 caddr_t data __unused, int flags __unused, struct thread *td __unused)
167 {
168 return (ENOTTY);
169 }
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