xref: /freebsd/sys/amd64/amd64/mem.c (revision 0c43d89a0d8e976ca494d4837f4c1f3734d2c300)
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  * 3. All advertising materials mentioning features or use of this software
20  *    must display the following acknowledgement:
21  *	This product includes software developed by the University of
22  *	California, Berkeley and its contributors.
23  * 4. Neither the name of the University nor the names of its contributors
24  *    may be used to endorse or promote products derived from this software
25  *    without specific prior written permission.
26  *
27  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
28  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
29  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
30  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
31  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
32  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
33  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
34  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
35  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
36  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
37  * SUCH DAMAGE.
38  *
39  *	from: Utah $Hdr: mem.c 1.13 89/10/08$
40  *	from: @(#)mem.c	7.2 (Berkeley) 5/9/91
41  *	$Id: mem.c,v 1.8 1994/05/25 08:54:24 rgrimes Exp $
42  */
43 
44 /*
45  * Memory special file
46  */
47 
48 #include <sys/param.h>
49 #include <sys/conf.h>
50 #include <sys/buf.h>
51 #include <sys/systm.h>
52 #include <sys/uio.h>
53 #include <sys/malloc.h>
54 #include <sys/proc.h>
55 
56 #include <machine/cpu.h>
57 #include <machine/psl.h>
58 
59 #include <vm/vm.h>
60 #include <vm/vm_param.h>
61 #include <vm/lock.h>
62 #include <vm/vm_prot.h>
63 #include <vm/pmap.h>
64 
65 extern        char *ptvmmap;            /* poor name! */
66 /*ARGSUSED*/
67 int
68 mmclose(dev, uio, flags)
69 	dev_t dev;
70 	struct uio *uio;
71 	int flags;
72 {
73 	struct trapframe *fp;
74 
75 	switch (minor(dev)) {
76 	case 14:
77 		fp = (struct trapframe *)curproc->p_md.md_regs;
78 		fp->tf_eflags &= ~PSL_IOPL;
79 		break;
80 	default:
81 		break;
82 	}
83 	return(0);
84 }
85 /*ARGSUSED*/
86 int
87 mmopen(dev, uio, flags)
88 	dev_t dev;
89 	struct uio *uio;
90 	int flags;
91 {
92 	struct trapframe *fp;
93 
94 	switch (minor(dev)) {
95 	case 14:
96 		fp = (struct trapframe *)curproc->p_md.md_regs;
97 		fp->tf_eflags |= PSL_IOPL;
98 		break;
99 	default:
100 		break;
101 	}
102 	return(0);
103 }
104 /*ARGSUSED*/
105 int
106 mmrw(dev, uio, flags)
107 	dev_t dev;
108 	struct uio *uio;
109 	int flags;
110 {
111 	register int o;
112 	register u_int c, v;
113 	register struct iovec *iov;
114 	int error = 0;
115 	caddr_t zbuf = NULL;
116 
117 	while (uio->uio_resid > 0 && error == 0) {
118 		iov = uio->uio_iov;
119 		if (iov->iov_len == 0) {
120 			uio->uio_iov++;
121 			uio->uio_iovcnt--;
122 			if (uio->uio_iovcnt < 0)
123 				panic("mmrw");
124 			continue;
125 		}
126 		switch (minor(dev)) {
127 
128 /* minor device 0 is physical memory */
129 		case 0:
130 			v = uio->uio_offset;
131 			pmap_enter(kernel_pmap, (vm_offset_t)ptvmmap, v,
132 				uio->uio_rw == UIO_READ ? VM_PROT_READ : VM_PROT_WRITE,
133 				TRUE);
134 			o = (int)uio->uio_offset & PGOFSET;
135 			c = (u_int)(NBPG - ((int)iov->iov_base & PGOFSET));
136 			c = min(c, (u_int)(NBPG - o));
137 			c = min(c, (u_int)iov->iov_len);
138 			error = uiomove((caddr_t)&ptvmmap[o], (int)c, uio);
139 			pmap_remove(kernel_pmap, (vm_offset_t)ptvmmap,
140 				    (vm_offset_t)&ptvmmap[NBPG]);
141 			continue;
142 
143 /* minor device 1 is kernel memory */
144 		case 1:
145 			c = iov->iov_len;
146 			if (!kernacc((caddr_t)(int)uio->uio_offset, c,
147 			    uio->uio_rw == UIO_READ ? B_READ : B_WRITE))
148 				return(EFAULT);
149 			error = uiomove((caddr_t)(int)uio->uio_offset, (int)c, uio);
150 			continue;
151 
152 /* minor device 2 is EOF/RATHOLE */
153 		case 2:
154 			if (uio->uio_rw == UIO_READ)
155 				return (0);
156 			c = iov->iov_len;
157 			break;
158 
159 /* minor device 12 (/dev/zero) is source of nulls on read, rathole on write */
160 		case 12:
161 			if (uio->uio_rw == UIO_WRITE) {
162 				c = iov->iov_len;
163 				break;
164 			}
165 			if (zbuf == NULL) {
166 				zbuf = (caddr_t)
167 				    malloc(CLBYTES, M_TEMP, M_WAITOK);
168 				bzero(zbuf, CLBYTES);
169 			}
170 			c = min(iov->iov_len, CLBYTES);
171 			error = uiomove(zbuf, (int)c, uio);
172 			continue;
173 
174 #ifdef notyet
175 /* 386 I/O address space (/dev/ioport[bwl]) is a read/write access to seperate
176    i/o device address bus, different than memory bus. Semantics here are
177    very different than ordinary read/write, as if iov_len is a multiple
178    an implied string move from a single port will be done. Note that lseek
179    must be used to set the port number reliably. */
180 		case 14:
181 			if (iov->iov_len == 1) {
182 				u_char tmp;
183 				tmp = inb(uio->uio_offset);
184 				error = uiomove (&tmp, iov->iov_len, uio);
185 			} else {
186 				if (!useracc((caddr_t)iov->iov_base,
187 					iov->iov_len, uio->uio_rw))
188 					return (EFAULT);
189 				insb(uio->uio_offset, iov->iov_base,
190 					iov->iov_len);
191 			}
192 			break;
193 		case 15:
194 			if (iov->iov_len == sizeof (short)) {
195 				u_short tmp;
196 				tmp = inw(uio->uio_offset);
197 				error = uiomove (&tmp, iov->iov_len, uio);
198 			} else {
199 				if (!useracc((caddr_t)iov->iov_base,
200 					iov->iov_len, uio->uio_rw))
201 					return (EFAULT);
202 				insw(uio->uio_offset, iov->iov_base,
203 					iov->iov_len/ sizeof (short));
204 			}
205 			break;
206 		case 16:
207 			if (iov->iov_len == sizeof (long)) {
208 				u_long tmp;
209 				tmp = inl(uio->uio_offset);
210 				error = uiomove (&tmp, iov->iov_len, uio);
211 			} else {
212 				if (!useracc((caddr_t)iov->iov_base,
213 					iov->iov_len, uio->uio_rw))
214 					return (EFAULT);
215 				insl(uio->uio_offset, iov->iov_base,
216 					iov->iov_len/ sizeof (long));
217 			}
218 			break;
219 #endif
220 
221 		default:
222 			return (ENXIO);
223 		}
224 		if (error)
225 			break;
226 		iov->iov_base += c;
227 		iov->iov_len -= c;
228 		uio->uio_offset += c;
229 		uio->uio_resid -= c;
230 	}
231 	if (zbuf)
232 		free(zbuf, M_TEMP);
233 	return (error);
234 }
235 
236 
237 
238 
239 /*******************************************************\
240 * allow user processes to MMAP some memory sections	*
241 * instead of going through read/write			*
242 \*******************************************************/
243 int memmmap(dev_t dev, int offset, int nprot)
244 {
245 	switch (minor(dev))
246 	{
247 
248 /* minor device 0 is physical memory */
249 	case 0:
250         	return i386_btop(offset);
251 
252 /* minor device 1 is kernel memory */
253 	case 1:
254         	return i386_btop(vtophys(offset));
255 
256 	default:
257 		return -1;
258 	}
259 }
260 
261