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 * from: @(#)mem.c 7.2 (Berkeley) 5/9/91
39 */
40
41 #include <sys/cdefs.h>
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/sx.h>
57 #include <sys/proc.h>
58 #include <sys/signalvar.h>
59 #include <sys/systm.h>
60 #include <sys/uio.h>
61
62 #include <machine/specialreg.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 static struct sx memsxlock;
76 SX_SYSINIT(memsxlockinit, &memsxlock, "/dev/mem lock");
77
78 /* ARGSUSED */
79 int
memrw(struct cdev * dev,struct uio * uio,int flags)80 memrw(struct cdev *dev, struct uio *uio, int flags)
81 {
82 int o;
83 u_int c = 0;
84 vm_paddr_t pa;
85 struct iovec *iov;
86 int error = 0;
87 vm_offset_t addr;
88
89 if (dev2unit(dev) != CDEV_MINOR_MEM && dev2unit(dev) != CDEV_MINOR_KMEM)
90 return EIO;
91
92 if (dev2unit(dev) == CDEV_MINOR_KMEM && uio->uio_resid > 0) {
93 if (!kernacc((caddr_t)(int)uio->uio_offset, uio->uio_resid,
94 uio->uio_rw == UIO_READ ? VM_PROT_READ : VM_PROT_WRITE))
95 return (EFAULT);
96 }
97
98 while (uio->uio_resid > 0 && error == 0) {
99 iov = uio->uio_iov;
100 if (iov->iov_len == 0) {
101 uio->uio_iov++;
102 uio->uio_iovcnt--;
103 if (uio->uio_iovcnt < 0)
104 panic("memrw");
105 continue;
106 }
107 if (dev2unit(dev) == CDEV_MINOR_MEM) {
108 if (uio->uio_offset > cpu_getmaxphyaddr()) {
109 error = EFAULT;
110 break;
111 }
112 pa = trunc_page(uio->uio_offset);
113 } else {
114 /*
115 * Extract the physical page since the mapping may
116 * change at any time. This avoids panics on page
117 * fault in this case but will cause reading/writing
118 * to the wrong page.
119 * Hopefully an application will notice the wrong
120 * data on read access and refrain from writing.
121 * This should be replaced by a special uiomove
122 * type function that just returns an error if there
123 * is a page fault on a kernel page.
124 */
125 addr = trunc_page(uio->uio_offset);
126 pa = pmap_extract(kernel_pmap, addr);
127 if (pa == 0)
128 return EFAULT;
129 }
130
131 /*
132 * XXX UPS This should just use sf_buf_alloc.
133 * Unfortunately sf_buf_alloc needs a vm_page
134 * and we may want to look at memory not covered
135 * by the page array.
136 */
137
138 sx_xlock(&memsxlock);
139 pmap_kenter((vm_offset_t)ptvmmap, pa);
140 pmap_invalidate_page(kernel_pmap,(vm_offset_t)ptvmmap);
141
142 o = (int)uio->uio_offset & PAGE_MASK;
143 c = PAGE_SIZE - o;
144 c = min(c, (u_int)iov->iov_len);
145 error = uiomove((caddr_t)&ptvmmap[o], (int)c, uio);
146 pmap_qremove((vm_offset_t)ptvmmap, 1);
147 sx_xunlock(&memsxlock);
148 }
149
150 return (error);
151 }
152
153 /*
154 * allow user processes to MMAP some memory sections
155 * instead of going through read/write
156 */
157 /* ARGSUSED */
158 int
memmmap(struct cdev * dev,vm_ooffset_t offset,vm_paddr_t * paddr,int prot __unused,vm_memattr_t * memattr __unused)159 memmmap(struct cdev *dev, vm_ooffset_t offset, vm_paddr_t *paddr,
160 int prot __unused, vm_memattr_t *memattr __unused)
161 {
162 if (dev2unit(dev) == CDEV_MINOR_MEM) {
163 if (offset > cpu_getmaxphyaddr())
164 return (-1);
165 *paddr = offset;
166 return (0);
167 }
168 return (-1);
169 }
170
171 /*
172 * Operations for changing memory attributes.
173 *
174 * This is basically just an ioctl shim for mem_range_attr_get
175 * and mem_range_attr_set.
176 */
177 int
memioctl_md(struct cdev * dev __unused,u_long cmd,caddr_t data,int flags,struct thread * td)178 memioctl_md(struct cdev *dev __unused, u_long cmd, caddr_t data, int flags,
179 struct thread *td)
180 {
181 int nd, error = 0;
182 struct mem_range_op *mo = (struct mem_range_op *)data;
183 struct mem_range_desc *md;
184
185 /* is this for us? */
186 if ((cmd != MEMRANGE_GET) &&
187 (cmd != MEMRANGE_SET))
188 return (ENOTTY);
189
190 /* any chance we can handle this? */
191 if (mem_range_softc.mr_op == NULL)
192 return (EOPNOTSUPP);
193
194 /* do we have any descriptors? */
195 if (mem_range_softc.mr_ndesc == 0)
196 return (ENXIO);
197
198 switch (cmd) {
199 case MEMRANGE_GET:
200 nd = imin(mo->mo_arg[0], mem_range_softc.mr_ndesc);
201 if (nd > 0) {
202 md = (struct mem_range_desc *)
203 malloc(nd * sizeof(struct mem_range_desc),
204 M_MEMDESC, M_WAITOK);
205 error = mem_range_attr_get(md, &nd);
206 if (!error)
207 error = copyout(md, mo->mo_desc,
208 nd * sizeof(struct mem_range_desc));
209 free(md, M_MEMDESC);
210 }
211 else
212 nd = mem_range_softc.mr_ndesc;
213 mo->mo_arg[0] = nd;
214 break;
215
216 case MEMRANGE_SET:
217 md = (struct mem_range_desc *)malloc(sizeof(struct mem_range_desc),
218 M_MEMDESC, M_WAITOK);
219 error = copyin(mo->mo_desc, md, sizeof(struct mem_range_desc));
220 /* clamp description string */
221 md->mr_owner[sizeof(md->mr_owner) - 1] = 0;
222 if (error == 0)
223 error = mem_range_attr_set(md, &mo->mo_arg[0]);
224 free(md, M_MEMDESC);
225 break;
226 }
227 return (error);
228 }
229