1 /*-
2 * SPDX-License-Identifier: BSD-3-Clause
3 *
4 * Copyright (c) 1988 University of Utah.
5 * Copyright (c) 1982, 1986, 1990 The Regents of the University of California.
6 * All rights reserved.
7 *
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.
12 *
13 * Redistribution and use in source and binary forms, with or without
14 * modification, are permitted provided that the following conditions
15 * are met:
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.
24 *
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
35 * SUCH DAMAGE.
36 *
37 * from: Utah $Hdr: mem.c 1.13 89/10/08$
38 */
39
40 #include <sys/cdefs.h>
41 /*
42 * Memory special file
43 */
44
45 #include <sys/param.h>
46 #include <sys/conf.h>
47 #include <sys/fcntl.h>
48 #include <sys/ioccom.h>
49 #include <sys/kernel.h>
50 #include <sys/lock.h>
51 #include <sys/malloc.h>
52 #include <sys/memrange.h>
53 #include <sys/module.h>
54 #include <sys/mutex.h>
55 #include <sys/proc.h>
56 #include <sys/signalvar.h>
57 #include <sys/systm.h>
58 #include <sys/uio.h>
59
60 #include <machine/md_var.h>
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
memrw(struct cdev * dev,struct uio * uio,int flags)77 memrw(struct cdev *dev, struct uio *uio, int flags)
78 {
79 struct iovec *iov;
80 void *p;
81 ssize_t orig_resid;
82 vm_prot_t prot;
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 switch (uio->uio_rw) {
115 case UIO_READ:
116 prot = VM_PROT_READ;
117 break;
118 case UIO_WRITE:
119 prot = VM_PROT_WRITE;
120 break;
121 }
122
123 if (!kernacc((void *)v, c, prot)) {
124 error = EFAULT;
125 break;
126 }
127
128 /*
129 * If the extracted address is not accessible
130 * through the direct map, then we make a
131 * private (uncached) mapping because we can't
132 * depend on the existing kernel mapping
133 * remaining valid until the completion of
134 * uiomove().
135 *
136 * XXX We cannot provide access to the
137 * physical page 0 mapped into KVA.
138 */
139 v = pmap_extract(kernel_pmap, v);
140 if (v == 0) {
141 error = EFAULT;
142 break;
143 }
144 /* FALLTHROUGH */
145 case CDEV_MINOR_MEM:
146 if (v < dmaplimit) {
147 vd = PHYS_TO_DMAP(v);
148 error = uiomove((void *)vd, c, uio);
149 break;
150 }
151 if (v > cpu_getmaxphyaddr()) {
152 error = EFAULT;
153 break;
154 }
155 p = pmap_mapdev(v, PAGE_SIZE);
156 error = uiomove(p, c, uio);
157 pmap_unmapdev(p, PAGE_SIZE);
158 break;
159 }
160 }
161 /*
162 * Don't return error if any byte was written. Read and write
163 * can return error only if no i/o was performed.
164 */
165 if (uio->uio_resid != orig_resid)
166 error = 0;
167 return (error);
168 }
169
170 /*
171 * allow user processes to MMAP some memory sections
172 * instead of going through read/write
173 */
174 /* ARGSUSED */
175 int
memmmap(struct cdev * dev,vm_ooffset_t offset,vm_paddr_t * paddr,int prot __unused,vm_memattr_t * memattr __unused)176 memmmap(struct cdev *dev, vm_ooffset_t offset, vm_paddr_t *paddr,
177 int prot __unused, vm_memattr_t *memattr __unused)
178 {
179 if (dev2unit(dev) == CDEV_MINOR_MEM) {
180 if (offset > cpu_getmaxphyaddr())
181 return (-1);
182 *paddr = offset;
183 return (0);
184 }
185 return (-1);
186 }
187
188 /*
189 * Operations for changing memory attributes.
190 *
191 * This is basically just an ioctl shim for mem_range_attr_get
192 * and mem_range_attr_set.
193 */
194 int
memioctl_md(struct cdev * dev __unused,u_long cmd,caddr_t data,int flags,struct thread * td)195 memioctl_md(struct cdev *dev __unused, u_long cmd, caddr_t data, int flags,
196 struct thread *td)
197 {
198 int nd, error = 0;
199 struct mem_range_op *mo = (struct mem_range_op *)data;
200 struct mem_range_desc *md;
201
202 /* is this for us? */
203 if ((cmd != MEMRANGE_GET) &&
204 (cmd != MEMRANGE_SET))
205 return (ENOTTY);
206
207 /* any chance we can handle this? */
208 if (mem_range_softc.mr_op == NULL)
209 return (EOPNOTSUPP);
210
211 /* do we have any descriptors? */
212 if (mem_range_softc.mr_ndesc == 0)
213 return (ENXIO);
214
215 switch (cmd) {
216 case MEMRANGE_GET:
217 nd = imin(mo->mo_arg[0], mem_range_softc.mr_ndesc);
218 if (nd > 0) {
219 md = (struct mem_range_desc *)
220 malloc(nd * sizeof(struct mem_range_desc),
221 M_MEMDESC, M_WAITOK);
222 error = mem_range_attr_get(md, &nd);
223 if (!error)
224 error = copyout(md, mo->mo_desc,
225 nd * sizeof(struct mem_range_desc));
226 free(md, M_MEMDESC);
227 }
228 else
229 nd = mem_range_softc.mr_ndesc;
230 mo->mo_arg[0] = nd;
231 break;
232
233 case MEMRANGE_SET:
234 md = (struct mem_range_desc *)malloc(sizeof(struct mem_range_desc),
235 M_MEMDESC, M_WAITOK);
236 error = copyin(mo->mo_desc, md, sizeof(struct mem_range_desc));
237 /* clamp description string */
238 md->mr_owner[sizeof(md->mr_owner) - 1] = 0;
239 if (error == 0)
240 error = mem_range_attr_set(md, &mo->mo_arg[0]);
241 free(md, M_MEMDESC);
242 break;
243 }
244 return (error);
245 }
246