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/10.4/sys/amd64/amd64/mem.c 309426 2016-12-02 19:02:12Z jhb $");
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/md_var.h>
62 #include <machine/specialreg.h>
63 #include <machine/vmparam.h>
64
65 #include <vm/vm.h>
66 #include <vm/pmap.h>
67 #include <vm/vm_extern.h>
68
69 #include <machine/memdev.h>
70
71 /*
72 * Used in /dev/mem drivers and elsewhere
73 */
74 MALLOC_DEFINE(M_MEMDESC, "memdesc", "memory range descriptors");
75
76 /* ARGSUSED */
77 int
78 memrw(struct cdev *dev, struct uio *uio, int flags)
79 {
80 struct iovec *iov;
81 void *p;
82 ssize_t orig_resid;
83 u_long v, vd;
84 u_int c;
85 int error;
86
87 error = 0;
88 orig_resid = uio->uio_resid;
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 v = uio->uio_offset;
99 c = ulmin(iov->iov_len, PAGE_SIZE - (u_int)(v & PAGE_MASK));
100
101 switch (dev2unit(dev)) {
102 case CDEV_MINOR_KMEM:
103 /*
104 * Since c is clamped to be less or equal than
105 * PAGE_SIZE, the uiomove() call does not
106 * access past the end of the direct map.
107 */
108 if (v >= DMAP_MIN_ADDRESS &&
109 v < DMAP_MIN_ADDRESS + dmaplimit) {
110 error = uiomove((void *)v, c, uio);
111 break;
112 }
113
114 if (!kernacc((void *)v, c, uio->uio_rw == UIO_READ ?
115 VM_PROT_READ : VM_PROT_WRITE)) {
116 error = EFAULT;
117 break;
118 }
119
120 /*
121 * If the extracted address is not accessible
122 * through the direct map, then we make a
123 * private (uncached) mapping because we can't
124 * depend on the existing kernel mapping
125 * remaining valid until the completion of
126 * uiomove().
127 *
128 * XXX We cannot provide access to the
129 * physical page 0 mapped into KVA.
130 */
131 v = pmap_extract(kernel_pmap, v);
132 if (v == 0) {
133 error = EFAULT;
134 break;
135 }
136 /* FALLTHROUGH */
137 case CDEV_MINOR_MEM:
138 if (v < dmaplimit) {
139 vd = PHYS_TO_DMAP(v);
140 error = uiomove((void *)vd, c, uio);
141 break;
142 }
143 if (v > cpu_getmaxphyaddr()) {
144 error = EFAULT;
145 break;
146 }
147 p = pmap_mapdev(v, PAGE_SIZE);
148 error = uiomove(p, c, uio);
149 pmap_unmapdev((vm_offset_t)p, PAGE_SIZE);
150 break;
151 }
152 }
153 /*
154 * Don't return error if any byte was written. Read and write
155 * can return error only if no i/o was performed.
156 */
157 if (uio->uio_resid != orig_resid)
158 error = 0;
159 return (error);
160 }
161
162 /*
163 * allow user processes to MMAP some memory sections
164 * instead of going through read/write
165 */
166 /* ARGSUSED */
167 int
168 memmmap(struct cdev *dev, vm_ooffset_t offset, vm_paddr_t *paddr,
169 int prot __unused, vm_memattr_t *memattr __unused)
170 {
171 if (dev2unit(dev) == CDEV_MINOR_MEM) {
172 if (offset > cpu_getmaxphyaddr())
173 return (-1);
174 *paddr = offset;
175 } else if (dev2unit(dev) == CDEV_MINOR_KMEM)
176 *paddr = vtophys(offset);
177 /* else panic! */
178 return (0);
179 }
180
181 /*
182 * Operations for changing memory attributes.
183 *
184 * This is basically just an ioctl shim for mem_range_attr_get
185 * and mem_range_attr_set.
186 */
187 /* ARGSUSED */
188 int
189 memioctl(struct cdev *dev __unused, u_long cmd, caddr_t data, int flags,
190 struct thread *td)
191 {
192 int nd, error = 0;
193 struct mem_range_op *mo = (struct mem_range_op *)data;
194 struct mem_range_desc *md;
195
196 /* is this for us? */
197 if ((cmd != MEMRANGE_GET) &&
198 (cmd != MEMRANGE_SET))
199 return (ENOTTY);
200
201 /* any chance we can handle this? */
202 if (mem_range_softc.mr_op == NULL)
203 return (EOPNOTSUPP);
204
205 /* do we have any descriptors? */
206 if (mem_range_softc.mr_ndesc == 0)
207 return (ENXIO);
208
209 switch (cmd) {
210 case MEMRANGE_GET:
211 nd = imin(mo->mo_arg[0], mem_range_softc.mr_ndesc);
212 if (nd > 0) {
213 md = (struct mem_range_desc *)
214 malloc(nd * sizeof(struct mem_range_desc),
215 M_MEMDESC, M_WAITOK);
216 error = mem_range_attr_get(md, &nd);
217 if (!error)
218 error = copyout(md, mo->mo_desc,
219 nd * sizeof(struct mem_range_desc));
220 free(md, M_MEMDESC);
221 }
222 else
223 nd = mem_range_softc.mr_ndesc;
224 mo->mo_arg[0] = nd;
225 break;
226
227 case MEMRANGE_SET:
228 md = (struct mem_range_desc *)malloc(sizeof(struct mem_range_desc),
229 M_MEMDESC, M_WAITOK);
230 error = copyin(mo->mo_desc, md, sizeof(struct mem_range_desc));
231 /* clamp description string */
232 md->mr_owner[sizeof(md->mr_owner) - 1] = 0;
233 if (error == 0)
234 error = mem_range_attr_set(md, &mo->mo_arg[0]);
235 free(md, M_MEMDESC);
236 break;
237 }
238 return (error);
239 }
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