FreeBSD/Linux Kernel Cross Reference
sys/amd64/amd64/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/amd64/amd64/mem.c 263875 2014-03-28 15:38:38Z 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/systm.h>
59 #include <sys/uio.h>
60
61 #include <machine/specialreg.h>
62 #include <machine/vmparam.h>
63
64 #include <vm/vm.h>
65 #include <vm/pmap.h>
66 #include <vm/vm_extern.h>
67
68 #include <machine/memdev.h>
69
70 /*
71 * Used in /dev/mem drivers and elsewhere
72 */
73 MALLOC_DEFINE(M_MEMDESC, "memdesc", "memory range descriptors");
74
75 /* ARGSUSED */
76 int
77 memrw(struct cdev *dev, struct uio *uio, int flags)
78 {
79 struct iovec *iov;
80 u_long c, v;
81 int error, o, sflags;
82 vm_offset_t addr, eaddr;
83
84 GIANT_REQUIRED;
85
86 error = 0;
87 c = 0;
88 sflags = curthread_pflags_set(TDP_DEVMEMIO);
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 v = uio->uio_offset;
100 kmemphys:
101 o = v & PAGE_MASK;
102 c = min(uio->uio_resid, (u_int)(PAGE_SIZE - o));
103 v = PHYS_TO_DMAP(v);
104 if (v < DMAP_MIN_ADDRESS ||
105 (v > DMAP_MIN_ADDRESS + dmaplimit &&
106 v <= DMAP_MAX_ADDRESS) ||
107 pmap_kextract(v) == 0) {
108 error = EFAULT;
109 goto ret;
110 }
111 error = uiomove((void *)v, (int)c, uio);
112 continue;
113 }
114 else if (dev2unit(dev) == CDEV_MINOR_KMEM) {
115 v = uio->uio_offset;
116
117 if (v >= DMAP_MIN_ADDRESS && v < DMAP_MAX_ADDRESS) {
118 v = DMAP_TO_PHYS(v);
119 goto kmemphys;
120 }
121
122 c = iov->iov_len;
123
124 /*
125 * Make sure that all of the pages are currently
126 * resident so that we don't create any zero-fill
127 * pages.
128 */
129 addr = trunc_page(v);
130 eaddr = round_page(v + c);
131
132 if (addr < VM_MIN_KERNEL_ADDRESS) {
133 error = EFAULT;
134 goto ret;
135 }
136 for (; addr < eaddr; addr += PAGE_SIZE) {
137 if (pmap_extract(kernel_pmap, addr) == 0) {
138 error = EFAULT;
139 goto ret;
140 }
141 }
142 if (!kernacc((caddr_t)(long)v, c,
143 uio->uio_rw == UIO_READ ?
144 VM_PROT_READ : VM_PROT_WRITE)) {
145 error = EFAULT;
146 goto ret;
147 }
148
149 error = uiomove((caddr_t)(long)v, (int)c, uio);
150 continue;
151 }
152 /* else panic! */
153 }
154 ret:
155 curthread_pflags_restore(sflags);
156 return (error);
157 }
158
159 /*
160 * allow user processes to MMAP some memory sections
161 * instead of going through read/write
162 */
163 /* ARGSUSED */
164 int
165 memmmap(struct cdev *dev, vm_ooffset_t offset, vm_paddr_t *paddr,
166 int prot __unused, vm_memattr_t *memattr __unused)
167 {
168 if (dev2unit(dev) == CDEV_MINOR_MEM)
169 *paddr = offset;
170 else if (dev2unit(dev) == CDEV_MINOR_KMEM)
171 *paddr = vtophys(offset);
172 /* else panic! */
173 return (0);
174 }
175
176 /*
177 * Operations for changing memory attributes.
178 *
179 * This is basically just an ioctl shim for mem_range_attr_get
180 * and mem_range_attr_set.
181 */
182 /* ARGSUSED */
183 int
184 memioctl(struct cdev *dev __unused, u_long cmd, caddr_t data, int flags,
185 struct thread *td)
186 {
187 int nd, error = 0;
188 struct mem_range_op *mo = (struct mem_range_op *)data;
189 struct mem_range_desc *md;
190
191 /* is this for us? */
192 if ((cmd != MEMRANGE_GET) &&
193 (cmd != MEMRANGE_SET))
194 return (ENOTTY);
195
196 /* any chance we can handle this? */
197 if (mem_range_softc.mr_op == NULL)
198 return (EOPNOTSUPP);
199
200 /* do we have any descriptors? */
201 if (mem_range_softc.mr_ndesc == 0)
202 return (ENXIO);
203
204 switch (cmd) {
205 case MEMRANGE_GET:
206 nd = imin(mo->mo_arg[0], mem_range_softc.mr_ndesc);
207 if (nd > 0) {
208 md = (struct mem_range_desc *)
209 malloc(nd * sizeof(struct mem_range_desc),
210 M_MEMDESC, M_WAITOK);
211 error = mem_range_attr_get(md, &nd);
212 if (!error)
213 error = copyout(md, mo->mo_desc,
214 nd * sizeof(struct mem_range_desc));
215 free(md, M_MEMDESC);
216 }
217 else
218 nd = mem_range_softc.mr_ndesc;
219 mo->mo_arg[0] = nd;
220 break;
221
222 case MEMRANGE_SET:
223 md = (struct mem_range_desc *)malloc(sizeof(struct mem_range_desc),
224 M_MEMDESC, M_WAITOK);
225 error = copyin(mo->mo_desc, md, sizeof(struct mem_range_desc));
226 /* clamp description string */
227 md->mr_owner[sizeof(md->mr_owner) - 1] = 0;
228 if (error == 0)
229 error = mem_range_attr_set(md, &mo->mo_arg[0]);
230 free(md, M_MEMDESC);
231 break;
232 }
233 return (error);
234 }
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