xref: /freebsd/sys/amd64/amd64/mem.c (revision ad30f8e79bd1007cc2476e491bd21b4f5e389e0a)
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 <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 struct mem_range_softc mem_range_softc;
76 
77 /* ARGSUSED */
78 int
79 memrw(struct cdev *dev, struct uio *uio, int flags)
80 {
81 	int o;
82 	u_long c = 0, v;
83 	struct iovec *iov;
84 	int error = 0;
85 	vm_offset_t addr, eaddr;
86 
87 	GIANT_REQUIRED;
88 
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 		if (dev2unit(dev) == CDEV_MINOR_MEM) {
99 			v = uio->uio_offset;
100 kmemphys:
101 			o = v & PAGE_MASK;
102 			c = min(uio->uio_resid, (u_int)(PAGE_SIZE - o));
103 			error = uiomove((void *)PHYS_TO_DMAP(v), (int)c, uio);
104 			continue;
105 		}
106 		else if (dev2unit(dev) == CDEV_MINOR_KMEM) {
107 			v = uio->uio_offset;
108 
109 			if (v >= DMAP_MIN_ADDRESS && v < DMAP_MAX_ADDRESS) {
110 				v = DMAP_TO_PHYS(v);
111 				goto kmemphys;
112 			}
113 
114 			c = iov->iov_len;
115 
116 			/*
117 			 * Make sure that all of the pages are currently
118 			 * resident so that we don't create any zero-fill
119 			 * pages.
120 			 */
121 			addr = trunc_page(v);
122 			eaddr = round_page(v + c);
123 
124 			if (addr < VM_MIN_KERNEL_ADDRESS)
125 				return (EFAULT);
126 			for (; addr < eaddr; addr += PAGE_SIZE)
127 				if (pmap_extract(kernel_pmap, addr) == 0)
128 					return (EFAULT);
129 
130 			if (!kernacc((caddr_t)(long)v, c,
131 			    uio->uio_rw == UIO_READ ?
132 			    VM_PROT_READ : VM_PROT_WRITE))
133 				return (EFAULT);
134 
135 			error = uiomove((caddr_t)(long)v, (int)c, uio);
136 			continue;
137 		}
138 		/* else panic! */
139 	}
140 	return (error);
141 }
142 
143 /*
144  * allow user processes to MMAP some memory sections
145  * instead of going through read/write
146  */
147 /* ARGSUSED */
148 int
149 memmmap(struct cdev *dev, vm_ooffset_t offset, vm_paddr_t *paddr,
150     int prot __unused, vm_memattr_t *memattr __unused)
151 {
152 	if (dev2unit(dev) == CDEV_MINOR_MEM)
153 		*paddr = offset;
154 	else if (dev2unit(dev) == CDEV_MINOR_KMEM)
155         	*paddr = vtophys(offset);
156 	/* else panic! */
157 	return (0);
158 }
159 
160 /*
161  * Operations for changing memory attributes.
162  *
163  * This is basically just an ioctl shim for mem_range_attr_get
164  * and mem_range_attr_set.
165  */
166 /* ARGSUSED */
167 int
168 memioctl(struct cdev *dev __unused, u_long cmd, caddr_t data, int flags,
169     struct thread *td)
170 {
171 	int nd, error = 0;
172 	struct mem_range_op *mo = (struct mem_range_op *)data;
173 	struct mem_range_desc *md;
174 
175 	/* is this for us? */
176 	if ((cmd != MEMRANGE_GET) &&
177 	    (cmd != MEMRANGE_SET))
178 		return (ENOTTY);
179 
180 	/* any chance we can handle this? */
181 	if (mem_range_softc.mr_op == NULL)
182 		return (EOPNOTSUPP);
183 
184 	/* do we have any descriptors? */
185 	if (mem_range_softc.mr_ndesc == 0)
186 		return (ENXIO);
187 
188 	switch (cmd) {
189 	case MEMRANGE_GET:
190 		nd = imin(mo->mo_arg[0], mem_range_softc.mr_ndesc);
191 		if (nd > 0) {
192 			md = (struct mem_range_desc *)
193 				malloc(nd * sizeof(struct mem_range_desc),
194 				       M_MEMDESC, M_WAITOK);
195 			error = mem_range_attr_get(md, &nd);
196 			if (!error)
197 				error = copyout(md, mo->mo_desc,
198 					nd * sizeof(struct mem_range_desc));
199 			free(md, M_MEMDESC);
200 		}
201 		else
202 			nd = mem_range_softc.mr_ndesc;
203 		mo->mo_arg[0] = nd;
204 		break;
205 
206 	case MEMRANGE_SET:
207 		md = (struct mem_range_desc *)malloc(sizeof(struct mem_range_desc),
208 						    M_MEMDESC, M_WAITOK);
209 		error = copyin(mo->mo_desc, md, sizeof(struct mem_range_desc));
210 		/* clamp description string */
211 		md->mr_owner[sizeof(md->mr_owner) - 1] = 0;
212 		if (error == 0)
213 			error = mem_range_attr_set(md, &mo->mo_arg[0]);
214 		free(md, M_MEMDESC);
215 		break;
216 	}
217 	return (error);
218 }
219