mem.c revision 278746 
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: stable/10/sys/arm/arm/mem.c 278746 2015-02-14 08:44:12Z kib $");
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 */
72MALLOC_DEFINE(M_MEMDESC, "memdesc", "memory range descriptors");
73
74struct mem_range_softc mem_range_softc;
75
76static struct sx tmppt_lock;
77SX_SYSINIT(tmppt, &tmppt_lock, "mem4map");
78
79/* ARGSUSED */
80int
81memrw(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
157int
158memmmap(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}
168