xref: /freebsd/sys/amd64/amd64/mem.c (revision 2546665afcaf0d53dc2c7058fee96354b3680f5a)
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 struct mem_range_softc mem_range_softc;
75 
76 void
77 mem_range_AP_init(void)
78 {
79 	if (mem_range_softc.mr_op && mem_range_softc.mr_op->initAP)
80 		mem_range_softc.mr_op->initAP(&mem_range_softc);
81 }
82 
83 /* ARGSUSED */
84 int
85 memrw(struct cdev *dev, struct uio *uio, int flags)
86 {
87 	int o;
88 	u_long c = 0, v;
89 	struct iovec *iov;
90 	int error = 0;
91 	vm_offset_t addr, eaddr;
92 
93 	GIANT_REQUIRED;
94 
95 	while (uio->uio_resid > 0 && error == 0) {
96 		iov = uio->uio_iov;
97 		if (iov->iov_len == 0) {
98 			uio->uio_iov++;
99 			uio->uio_iovcnt--;
100 			if (uio->uio_iovcnt < 0)
101 				panic("memrw");
102 			continue;
103 		}
104 		if (minor(dev) == CDEV_MINOR_MEM) {
105 			v = uio->uio_offset;
106 kmemphys:
107 			o = v & PAGE_MASK;
108 			c = min(uio->uio_resid, (u_int)(PAGE_SIZE - o));
109 			error = uiomove((void *)PHYS_TO_DMAP(v), (int)c, uio);
110 			continue;
111 		}
112 		else if (minor(dev) == CDEV_MINOR_KMEM) {
113 			v = uio->uio_offset;
114 
115 			if (v >= DMAP_MIN_ADDRESS && v < DMAP_MAX_ADDRESS) {
116 				v = DMAP_TO_PHYS(v);
117 				goto kmemphys;
118 			}
119 
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(v);
128 			eaddr = round_page(v + c);
129 
130 			if (addr < (vm_offset_t)KERNBASE)
131 				return (EFAULT);
132 			for (; addr < eaddr; addr += PAGE_SIZE)
133 				if (pmap_extract(kernel_pmap, addr) == 0)
134 					return (EFAULT);
135 
136 			if (!kernacc((caddr_t)(long)v, c,
137 			    uio->uio_rw == UIO_READ ?
138 			    VM_PROT_READ : VM_PROT_WRITE))
139 				return (EFAULT);
140 
141 			error = uiomove((caddr_t)(long)v, (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 int
155 memmmap(struct cdev *dev, vm_offset_t offset, vm_paddr_t *paddr,
156     int prot __unused)
157 {
158 	if (minor(dev) == CDEV_MINOR_MEM)
159 		*paddr = offset;
160 	else if (minor(dev) == CDEV_MINOR_KMEM)
161         	*paddr = vtophys(offset);
162 	/* else panic! */
163 	return (0);
164 }
165 
166 /*
167  * Operations for changing memory attributes.
168  *
169  * This is basically just an ioctl shim for mem_range_attr_get
170  * and mem_range_attr_set.
171  */
172 /* ARGSUSED */
173 int
174 memioctl(struct cdev *dev __unused, u_long cmd, caddr_t data, int flags,
175     struct thread *td)
176 {
177 	int nd, error = 0;
178 	struct mem_range_op *mo = (struct mem_range_op *)data;
179 	struct mem_range_desc *md;
180 
181 	/* is this for us? */
182 	if ((cmd != MEMRANGE_GET) &&
183 	    (cmd != MEMRANGE_SET))
184 		return (ENOTTY);
185 
186 	/* any chance we can handle this? */
187 	if (mem_range_softc.mr_op == NULL)
188 		return (EOPNOTSUPP);
189 
190 	/* do we have any descriptors? */
191 	if (mem_range_softc.mr_ndesc == 0)
192 		return (ENXIO);
193 
194 	switch (cmd) {
195 	case MEMRANGE_GET:
196 		nd = imin(mo->mo_arg[0], mem_range_softc.mr_ndesc);
197 		if (nd > 0) {
198 			md = (struct mem_range_desc *)
199 				malloc(nd * sizeof(struct mem_range_desc),
200 				       M_MEMDESC, M_WAITOK);
201 			error = mem_range_attr_get(md, &nd);
202 			if (!error)
203 				error = copyout(md, mo->mo_desc,
204 					nd * sizeof(struct mem_range_desc));
205 			free(md, M_MEMDESC);
206 		}
207 		else
208 			nd = mem_range_softc.mr_ndesc;
209 		mo->mo_arg[0] = nd;
210 		break;
211 
212 	case MEMRANGE_SET:
213 		md = (struct mem_range_desc *)malloc(sizeof(struct mem_range_desc),
214 						    M_MEMDESC, M_WAITOK);
215 		error = copyin(mo->mo_desc, md, sizeof(struct mem_range_desc));
216 		/* clamp description string */
217 		md->mr_owner[sizeof(md->mr_owner) - 1] = 0;
218 		if (error == 0)
219 			error = mem_range_attr_set(md, &mo->mo_arg[0]);
220 		free(md, M_MEMDESC);
221 		break;
222 	}
223 	return (error);
224 }
225 
226 /*
227  * Implementation-neutral, kernel-callable functions for manipulating
228  * memory range attributes.
229  */
230 int
231 mem_range_attr_get(struct mem_range_desc *mrd, int *arg)
232 {
233 	/* can we handle this? */
234 	if (mem_range_softc.mr_op == NULL)
235 		return (EOPNOTSUPP);
236 
237 	if (*arg == 0)
238 		*arg = mem_range_softc.mr_ndesc;
239 	else
240 		bcopy(mem_range_softc.mr_desc, mrd,
241 			(*arg) * sizeof(struct mem_range_desc));
242 	return (0);
243 }
244 
245 int
246 mem_range_attr_set(struct mem_range_desc *mrd, int *arg)
247 {
248 	/* can we handle this? */
249 	if (mem_range_softc.mr_op == NULL)
250 		return (EOPNOTSUPP);
251 
252 	return (mem_range_softc.mr_op->set(&mem_range_softc, mrd, arg));
253 }
254 
255 void
256 dev_mem_md_init(void)
257 {
258 	if (mem_range_softc.mr_op != NULL)
259 		mem_range_softc.mr_op->init(&mem_range_softc);
260 }
261