2 * SPDX-License-Identifier: BSD-3-Clause
4 * Copyright (c) 1988 University of Utah.
5 * Copyright (c) 1982, 1986, 1990 The Regents of the University of California.
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.
13 * Redistribution and use in source and binary forms, with or without
14 * modification, are permitted provided that the following conditions
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.
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
37 * from: Utah $Hdr: mem.c 1.13 89/10/08$
38 * from: @(#)mem.c 7.2 (Berkeley) 5/9/91
41 #include <sys/cdefs.h>
42 __FBSDID("$FreeBSD$");
48 #include <sys/param.h>
50 #include <sys/fcntl.h>
51 #include <sys/ioccom.h>
52 #include <sys/kernel.h>
54 #include <sys/malloc.h>
55 #include <sys/memrange.h>
56 #include <sys/module.h>
57 #include <sys/mutex.h>
60 #include <sys/signalvar.h>
61 #include <sys/systm.h>
64 #include <machine/specialreg.h>
68 #include <vm/vm_extern.h>
70 #include <machine/memdev.h>
73 * Used in /dev/mem drivers and elsewhere
75 MALLOC_DEFINE(M_MEMDESC, "memdesc", "memory range descriptors");
77 static struct sx memsxlock;
78 SX_SYSINIT(memsxlockinit, &memsxlock, "/dev/mem lock");
82 memrw(struct cdev *dev, struct uio *uio, int flags)
91 if (dev2unit(dev) != CDEV_MINOR_MEM && dev2unit(dev) != CDEV_MINOR_KMEM)
94 if (dev2unit(dev) == CDEV_MINOR_KMEM && uio->uio_resid > 0) {
95 if (!kernacc((caddr_t)(int)uio->uio_offset, uio->uio_resid,
96 uio->uio_rw == UIO_READ ? VM_PROT_READ : VM_PROT_WRITE))
100 while (uio->uio_resid > 0 && error == 0) {
102 if (iov->iov_len == 0) {
105 if (uio->uio_iovcnt < 0)
109 if (dev2unit(dev) == CDEV_MINOR_MEM) {
110 if (uio->uio_offset > cpu_getmaxphyaddr()) {
114 pa = trunc_page(uio->uio_offset);
117 * Extract the physical page since the mapping may
118 * change at any time. This avoids panics on page
119 * fault in this case but will cause reading/writing
121 * Hopefully an application will notice the wrong
122 * data on read access and refrain from writing.
123 * This should be replaced by a special uiomove
124 * type function that just returns an error if there
125 * is a page fault on a kernel page.
127 addr = trunc_page(uio->uio_offset);
128 pa = pmap_extract(kernel_pmap, addr);
135 * XXX UPS This should just use sf_buf_alloc.
136 * Unfortunately sf_buf_alloc needs a vm_page
137 * and we may want to look at memory not covered
141 sx_xlock(&memsxlock);
142 pmap_kenter((vm_offset_t)ptvmmap, pa);
143 pmap_invalidate_page(kernel_pmap,(vm_offset_t)ptvmmap);
145 o = (int)uio->uio_offset & PAGE_MASK;
147 c = min(c, (u_int)iov->iov_len);
148 error = uiomove((caddr_t)&ptvmmap[o], (int)c, uio);
149 pmap_qremove((vm_offset_t)ptvmmap, 1);
150 sx_xunlock(&memsxlock);
158 * allow user processes to MMAP some memory sections
159 * instead of going through read/write
163 memmmap(struct cdev *dev, vm_ooffset_t offset, vm_paddr_t *paddr,
164 int prot __unused, vm_memattr_t *memattr __unused)
166 if (dev2unit(dev) == CDEV_MINOR_MEM) {
167 if (offset > cpu_getmaxphyaddr())
176 * Operations for changing memory attributes.
178 * This is basically just an ioctl shim for mem_range_attr_get
179 * and mem_range_attr_set.
183 memioctl(struct cdev *dev __unused, u_long cmd, caddr_t data, int flags,
187 struct mem_range_op *mo = (struct mem_range_op *)data;
188 struct mem_range_desc *md;
190 /* is this for us? */
191 if ((cmd != MEMRANGE_GET) &&
192 (cmd != MEMRANGE_SET))
195 /* any chance we can handle this? */
196 if (mem_range_softc.mr_op == NULL)
199 /* do we have any descriptors? */
200 if (mem_range_softc.mr_ndesc == 0)
205 nd = imin(mo->mo_arg[0], mem_range_softc.mr_ndesc);
207 md = (struct mem_range_desc *)
208 malloc(nd * sizeof(struct mem_range_desc),
209 M_MEMDESC, M_WAITOK);
210 error = mem_range_attr_get(md, &nd);
212 error = copyout(md, mo->mo_desc,
213 nd * sizeof(struct mem_range_desc));
217 nd = mem_range_softc.mr_ndesc;
222 md = (struct mem_range_desc *)malloc(sizeof(struct mem_range_desc),
223 M_MEMDESC, M_WAITOK);
224 error = copyin(mo->mo_desc, md, sizeof(struct mem_range_desc));
225 /* clamp description string */
226 md->mr_owner[sizeof(md->mr_owner) - 1] = 0;
228 error = mem_range_attr_set(md, &mo->mo_arg[0]);