FreeBSD/Linux Kernel Cross Reference
sys/i386/i386/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: src/sys/i386/i386/mem.c,v 1.116 2004/08/04 18:30:31 markm Exp $");
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 <machine/specialreg.h>
62
63 #include <vm/vm.h>
64 #include <vm/pmap.h>
65 #include <vm/vm_extern.h>
66
67 #include <machine/memdev.h>
68
69 /*
70 * Used in /dev/mem drivers and elsewhere
71 */
72 MALLOC_DEFINE(M_MEMDESC, "memdesc", "memory range descriptors");
73
74 /* ARGSUSED */
75 int
76 memrw(struct cdev *dev, struct uio *uio, int flags)
77 {
78 int o;
79 u_int c = 0, v;
80 struct iovec *iov;
81 int error = 0;
82 vm_offset_t addr, eaddr;
83
84 GIANT_REQUIRED;
85
86 while (uio->uio_resid > 0 && error == 0) {
87 iov = uio->uio_iov;
88 if (iov->iov_len == 0) {
89 uio->uio_iov++;
90 uio->uio_iovcnt--;
91 if (uio->uio_iovcnt < 0)
92 panic("memrw");
93 continue;
94 }
95 if (minor(dev) == CDEV_MINOR_MEM) {
96 v = uio->uio_offset;
97 v &= ~PAGE_MASK;
98 pmap_kenter((vm_offset_t)ptvmmap, v);
99 o = (int)uio->uio_offset & PAGE_MASK;
100 c = (u_int)(PAGE_SIZE - ((int)iov->iov_base & PAGE_MASK));
101 c = min(c, (u_int)(PAGE_SIZE - o));
102 c = min(c, (u_int)iov->iov_len);
103 error = uiomove((caddr_t)&ptvmmap[o], (int)c, uio);
104 pmap_qremove((vm_offset_t)ptvmmap, 1);
105 continue;
106 }
107 else if (minor(dev) == CDEV_MINOR_KMEM) {
108 c = iov->iov_len;
109
110 /*
111 * Make sure that all of the pages are currently
112 * resident so that we don't create any zero-fill
113 * pages.
114 */
115 addr = trunc_page(uio->uio_offset);
116 eaddr = round_page(uio->uio_offset + c);
117
118 if (addr < (vm_offset_t)VADDR(PTDPTDI, 0))
119 return (EFAULT);
120 for (; addr < eaddr; addr += PAGE_SIZE)
121 if (pmap_extract(kernel_pmap, addr) == 0)
122 return (EFAULT);
123
124 if (!kernacc((caddr_t)(int)uio->uio_offset, c,
125 uio->uio_rw == UIO_READ ?
126 VM_PROT_READ : VM_PROT_WRITE))
127 return (EFAULT);
128 error = uiomove((caddr_t)(int)uio->uio_offset, (int)c, uio);
129 continue;
130 }
131 /* else panic! */
132 }
133 return (error);
134 }
135
136 /*
137 * allow user processes to MMAP some memory sections
138 * instead of going through read/write
139 */
140 /* ARGSUSED */
141 int
142 memmmap(struct cdev *dev, vm_offset_t offset, vm_paddr_t *paddr,
143 int prot __unused)
144 {
145 if (minor(dev) == CDEV_MINOR_MEM)
146 *paddr = offset;
147 else if (minor(dev) == CDEV_MINOR_KMEM)
148 *paddr = vtophys(offset);
149 /* else panic! */
150 return (0);
151 }
152
153 /*
154 * Operations for changing memory attributes.
155 *
156 * This is basically just an ioctl shim for mem_range_attr_get
157 * and mem_range_attr_set.
158 */
159 /* ARGSUSED */
160 int
161 memioctl(struct cdev *dev __unused, u_long cmd, caddr_t data, int flags,
162 struct thread *td)
163 {
164 int nd, error = 0;
165 struct mem_range_op *mo = (struct mem_range_op *)data;
166 struct mem_range_desc *md;
167
168 /* is this for us? */
169 if ((cmd != MEMRANGE_GET) &&
170 (cmd != MEMRANGE_SET))
171 return (ENOTTY);
172
173 /* any chance we can handle this? */
174 if (mem_range_softc.mr_op == NULL)
175 return (EOPNOTSUPP);
176
177 /* do we have any descriptors? */
178 if (mem_range_softc.mr_ndesc == 0)
179 return (ENXIO);
180
181 switch (cmd) {
182 case MEMRANGE_GET:
183 nd = imin(mo->mo_arg[0], mem_range_softc.mr_ndesc);
184 if (nd > 0) {
185 md = (struct mem_range_desc *)
186 malloc(nd * sizeof(struct mem_range_desc),
187 M_MEMDESC, M_WAITOK);
188 error = mem_range_attr_get(md, &nd);
189 if (!error)
190 error = copyout(md, mo->mo_desc,
191 nd * sizeof(struct mem_range_desc));
192 free(md, M_MEMDESC);
193 }
194 else
195 nd = mem_range_softc.mr_ndesc;
196 mo->mo_arg[0] = nd;
197 break;
198
199 case MEMRANGE_SET:
200 md = (struct mem_range_desc *)malloc(sizeof(struct mem_range_desc),
201 M_MEMDESC, M_WAITOK);
202 error = copyin(mo->mo_desc, md, sizeof(struct mem_range_desc));
203 /* clamp description string */
204 md->mr_owner[sizeof(md->mr_owner) - 1] = 0;
205 if (error == 0)
206 error = mem_range_attr_set(md, &mo->mo_arg[0]);
207 free(md, M_MEMDESC);
208 break;
209 }
210 return (error);
211 }
212
213 void
214 dev_mem_md_init(void)
215 {
216 if (mem_range_softc.mr_op != NULL)
217 mem_range_softc.mr_op->init(&mem_range_softc);
218 }
Cache object: 30ce9293292c86e071b806fa648d93c6
|