xref: /freebsd/sys/arm/arm/mem.c (revision 39beb93c)
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("$FreeBSD$");
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 <vm/vm.h>
62 #include <vm/pmap.h>
63 #include <vm/vm_extern.h>
64 
65 #include <machine/memdev.h>
66 #include <machine/vmparam.h>
67 
68 /*
69  * Used in /dev/mem drivers and elsewhere
70  */
71 MALLOC_DEFINE(M_MEMDESC, "memdesc", "memory range descriptors");
72 
73 /* ARGSUSED */
74 int
75 memrw(struct cdev *dev, struct uio *uio, int flags)
76 {
77 	int o;
78 	u_int c = 0, v;
79 	struct iovec *iov;
80 	int error = 0;
81 	vm_offset_t addr, eaddr;
82 
83 	GIANT_REQUIRED;
84 
85 	while (uio->uio_resid > 0 && error == 0) {
86 		iov = uio->uio_iov;
87 		if (iov->iov_len == 0) {
88 			uio->uio_iov++;
89 			uio->uio_iovcnt--;
90 			if (uio->uio_iovcnt < 0)
91 				panic("memrw");
92 			continue;
93 		}
94 		if (dev2unit(dev) == CDEV_MINOR_MEM) {
95 			int i;
96 			int address_valid = 0;
97 
98 			v = uio->uio_offset;
99 			v &= ~PAGE_MASK;
100 			for (i = 0; dump_avail[i] || dump_avail[i + 1];
101 			i += 2) {
102 				if (v >= dump_avail[i] &&
103 				    v < dump_avail[i + 1]) {
104 					address_valid = 1;
105 					break;
106 				}
107 			}
108 			if (!address_valid)
109 				return (EINVAL);
110 			pmap_kenter((vm_offset_t)_tmppt, v);
111 			o = (int)uio->uio_offset & PAGE_MASK;
112 			c = (u_int)(PAGE_SIZE - ((int)iov->iov_base & PAGE_MASK));
113 			c = min(c, (u_int)(PAGE_SIZE - o));
114 			c = min(c, (u_int)iov->iov_len);
115 			error = uiomove((caddr_t)&_tmppt[o], (int)c, uio);
116 			pmap_qremove((vm_offset_t)_tmppt, 1);
117 			continue;
118 		}
119 		else if (dev2unit(dev) == CDEV_MINOR_KMEM) {
120 			c = iov->iov_len;
121 
122 			/*
123 			 * Make sure that all of the pages are currently
124 			 * resident so that we don't create any zero-fill
125 			 * pages.
126 			 */
127 			addr = trunc_page(uio->uio_offset);
128 			eaddr = round_page(uio->uio_offset + c);
129 
130 			for (; addr < eaddr; addr += PAGE_SIZE)
131 				if (pmap_extract(kernel_pmap, addr) == 0)
132 					return (EFAULT);
133 			if (!kernacc((caddr_t)(int)uio->uio_offset, c,
134 			    uio->uio_rw == UIO_READ ?
135 			    VM_PROT_READ : VM_PROT_WRITE))
136 #ifdef ARM_USE_SMALL_ALLOC
137 				if (addr <= VM_MAXUSER_ADDRESS ||
138 				    addr >= KERNBASE)
139 #endif
140 					return (EFAULT);
141 			error = uiomove((caddr_t)(int)uio->uio_offset, (int)c, uio);
142 			continue;
143 		}
144 		/* else panic! */
145 	}
146 	return (error);
147 }
148 
149 /*
150  * allow user processes to MMAP some memory sections
151  * instead of going through read/write
152  */
153 /* ARGSUSED */
154 
155 int
156 memmmap(struct cdev *dev, vm_offset_t offset, vm_paddr_t *paddr,
157     int prot __unused)
158 {
159 	if (dev2unit(dev) == CDEV_MINOR_MEM)
160 		*paddr = offset;
161 	else if (dev2unit(dev) == CDEV_MINOR_KMEM)
162         	*paddr = vtophys(offset);
163 	/* else panic! */
164 	return (0);
165 }
166 
167 void
168 dev_mem_md_init(void)
169 {
170 }
171