2 * SPDX-License-Identifier: BSD-3-Clause
4 * Copyright (c) 1988 University of Utah.
5 * Copyright (c) 1982, 1986, 1990 The Regents of the University of California.
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.
13 * Redistribution and use in source and binary forms, with or without
14 * modification, are permitted provided that the following conditions
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.
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
37 * from: Utah $Hdr: mem.c 1.13 89/10/08$
38 * from: @(#)mem.c 7.2 (Berkeley) 5/9/91
41 #include <sys/cdefs.h>
42 __FBSDID("$FreeBSD$");
48 #include <sys/param.h>
50 #include <sys/fcntl.h>
51 #include <sys/ioccom.h>
52 #include <sys/kernel.h>
54 #include <sys/malloc.h>
55 #include <sys/memrange.h>
56 #include <sys/module.h>
57 #include <sys/mutex.h>
59 #include <sys/signalvar.h>
61 #include <sys/systm.h>
66 #include <vm/vm_extern.h>
68 #include <machine/memdev.h>
69 #include <machine/vmparam.h>
72 * Used in /dev/mem drivers and elsewhere
74 MALLOC_DEFINE(M_MEMDESC, "memdesc", "memory range descriptors");
76 struct mem_range_softc mem_range_softc;
78 static struct sx tmppt_lock;
79 SX_SYSINIT(tmppt, &tmppt_lock, "mem4map");
83 memrw(struct cdev *dev, struct uio *uio, int flags)
89 vm_offset_t addr, eaddr;
91 while (uio->uio_resid > 0 && error == 0) {
93 if (iov->iov_len == 0) {
96 if (uio->uio_iovcnt < 0)
100 if (dev2unit(dev) == CDEV_MINOR_MEM) {
102 int address_valid = 0;
106 for (i = 0; dump_avail[i] || dump_avail[i + 1];
108 if (v >= dump_avail[i] &&
109 v < dump_avail[i + 1]) {
116 sx_xlock(&tmppt_lock);
117 pmap_kenter((vm_offset_t)_tmppt, v);
119 pmap_tlb_flush(kernel_pmap, (vm_offset_t)_tmppt);
121 o = (int)uio->uio_offset & PAGE_MASK;
122 c = (u_int)(PAGE_SIZE - ((int)iov->iov_base & PAGE_MASK));
123 c = min(c, (u_int)(PAGE_SIZE - o));
124 c = min(c, (u_int)iov->iov_len);
125 error = uiomove((caddr_t)&_tmppt[o], (int)c, uio);
126 pmap_qremove((vm_offset_t)_tmppt, 1);
127 sx_xunlock(&tmppt_lock);
130 else if (dev2unit(dev) == CDEV_MINOR_KMEM) {
134 * Make sure that all of the pages are currently
135 * resident so that we don't create any zero-fill
138 addr = trunc_page(uio->uio_offset);
139 eaddr = round_page(uio->uio_offset + c);
141 for (; addr < eaddr; addr += PAGE_SIZE)
142 if (pmap_extract(kernel_pmap, addr) == 0)
144 if (!kernacc((caddr_t)(int)uio->uio_offset, c,
145 uio->uio_rw == UIO_READ ?
146 VM_PROT_READ : VM_PROT_WRITE))
148 error = uiomove((caddr_t)(int)uio->uio_offset, (int)c, uio);
157 * allow user processes to MMAP some memory sections
158 * instead of going through read/write
163 memmmap(struct cdev *dev, vm_ooffset_t offset, vm_paddr_t *paddr,
164 int prot __unused, vm_memattr_t *memattr __unused)
166 if (dev2unit(dev) == CDEV_MINOR_MEM) {