xref: /freebsd/sys/amd64/amd64/mem.c (revision 1e413cf93298b5b97441a21d9a50fdcd0ee9945e)
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 /* ARGSUSED */
71 int
72 memrw(struct cdev *dev, struct uio *uio, int flags)
73 {
74 	int o;
75 	u_long c = 0, v;
76 	struct iovec *iov;
77 	int error = 0;
78 	vm_offset_t addr, eaddr;
79 
80 	GIANT_REQUIRED;
81 
82 	while (uio->uio_resid > 0 && error == 0) {
83 		iov = uio->uio_iov;
84 		if (iov->iov_len == 0) {
85 			uio->uio_iov++;
86 			uio->uio_iovcnt--;
87 			if (uio->uio_iovcnt < 0)
88 				panic("memrw");
89 			continue;
90 		}
91 		if (minor(dev) == CDEV_MINOR_MEM) {
92 			v = uio->uio_offset;
93 kmemphys:
94 			o = v & PAGE_MASK;
95 			c = min(uio->uio_resid, (u_int)(PAGE_SIZE - o));
96 			error = uiomove((void *)PHYS_TO_DMAP(v), (int)c, uio);
97 			continue;
98 		}
99 		else if (minor(dev) == CDEV_MINOR_KMEM) {
100 			v = uio->uio_offset;
101 
102 			if (v >= DMAP_MIN_ADDRESS && v < DMAP_MAX_ADDRESS) {
103 				v = DMAP_TO_PHYS(v);
104 				goto kmemphys;
105 			}
106 
107 			c = iov->iov_len;
108 
109 			/*
110 			 * Make sure that all of the pages are currently
111 			 * resident so that we don't create any zero-fill
112 			 * pages.
113 			 */
114 			addr = trunc_page(v);
115 			eaddr = round_page(v + c);
116 
117 			if (addr < (vm_offset_t)KERNBASE)
118 				return (EFAULT);
119 			for (; addr < eaddr; addr += PAGE_SIZE)
120 				if (pmap_extract(kernel_pmap, addr) == 0)
121 					return (EFAULT);
122 
123 			if (!kernacc((caddr_t)(long)v, c,
124 			    uio->uio_rw == UIO_READ ?
125 			    VM_PROT_READ : VM_PROT_WRITE))
126 				return (EFAULT);
127 
128 			error = uiomove((caddr_t)(long)v, (int)c, uio);
129 			continue;
130 		}
131 		/* else panic! */
132 	}
133 	return (error);
134 }
135 
136 /*
137  * allow user processes to MMAP some memory sections
138  * instead of going through read/write
139  */
140 /* ARGSUSED */
141 int
142 memmmap(struct cdev *dev, vm_offset_t offset, vm_paddr_t *paddr,
143     int prot __unused)
144 {
145 	if (minor(dev) == CDEV_MINOR_MEM)
146 		*paddr = offset;
147 	else if (minor(dev) == CDEV_MINOR_KMEM)
148         	*paddr = vtophys(offset);
149 	/* else panic! */
150 	return (0);
151 }
152 
153 /*
154  * Operations for changing memory attributes.
155  *
156  * This is basically just an ioctl shim for mem_range_attr_get
157  * and mem_range_attr_set.
158  */
159 /* ARGSUSED */
160 int
161 memioctl(struct cdev *dev __unused, u_long cmd, caddr_t data, int flags,
162     struct thread *td)
163 {
164 	int nd, error = 0;
165 	struct mem_range_op *mo = (struct mem_range_op *)data;
166 	struct mem_range_desc *md;
167 
168 	/* is this for us? */
169 	if ((cmd != MEMRANGE_GET) &&
170 	    (cmd != MEMRANGE_SET))
171 		return (ENOTTY);
172 
173 	/* any chance we can handle this? */
174 	if (mem_range_softc.mr_op == NULL)
175 		return (EOPNOTSUPP);
176 
177 	/* do we have any descriptors? */
178 	if (mem_range_softc.mr_ndesc == 0)
179 		return (ENXIO);
180 
181 	switch (cmd) {
182 	case MEMRANGE_GET:
183 		nd = imin(mo->mo_arg[0], mem_range_softc.mr_ndesc);
184 		if (nd > 0) {
185 			md = (struct mem_range_desc *)
186 				malloc(nd * sizeof(struct mem_range_desc),
187 				       M_MEMDESC, M_WAITOK);
188 			error = mem_range_attr_get(md, &nd);
189 			if (!error)
190 				error = copyout(md, mo->mo_desc,
191 					nd * sizeof(struct mem_range_desc));
192 			free(md, M_MEMDESC);
193 		}
194 		else
195 			nd = mem_range_softc.mr_ndesc;
196 		mo->mo_arg[0] = nd;
197 		break;
198 
199 	case MEMRANGE_SET:
200 		md = (struct mem_range_desc *)malloc(sizeof(struct mem_range_desc),
201 						    M_MEMDESC, M_WAITOK);
202 		error = copyin(mo->mo_desc, md, sizeof(struct mem_range_desc));
203 		/* clamp description string */
204 		md->mr_owner[sizeof(md->mr_owner) - 1] = 0;
205 		if (error == 0)
206 			error = mem_range_attr_set(md, &mo->mo_arg[0]);
207 		free(md, M_MEMDESC);
208 		break;
209 	}
210 	return (error);
211 }
212 
213 void
214 dev_mem_md_init(void)
215 {
216 	if (mem_range_softc.mr_op != NULL)
217 		mem_range_softc.mr_op->init(&mem_range_softc);
218 }
219