xref: /freebsd/sys/amd64/amd64/mem.c (revision 38f0b757fd84d17d0fc24739a7cda160c4516d81)
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 /* ARGSUSED */
76 int
77 memrw(struct cdev *dev, struct uio *uio, int flags)
78 {
79 	struct iovec *iov;
80 	u_long c, v;
81 	int error, o, sflags;
82 	vm_offset_t addr, eaddr;
83 
84 	GIANT_REQUIRED;
85 
86 	error = 0;
87 	c = 0;
88 	sflags = curthread_pflags_set(TDP_DEVMEMIO);
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 			v = PHYS_TO_DMAP(v);
104 			if (v < DMAP_MIN_ADDRESS ||
105 			    (v > DMAP_MIN_ADDRESS + dmaplimit &&
106 			    v <= DMAP_MAX_ADDRESS) ||
107 			    pmap_kextract(v) == 0) {
108 				error = EFAULT;
109 				goto ret;
110 			}
111 			error = uiomove((void *)v, (int)c, uio);
112 			continue;
113 		}
114 		else if (dev2unit(dev) == CDEV_MINOR_KMEM) {
115 			v = uio->uio_offset;
116 
117 			if (v >= DMAP_MIN_ADDRESS && v < DMAP_MAX_ADDRESS) {
118 				v = DMAP_TO_PHYS(v);
119 				goto kmemphys;
120 			}
121 
122 			c = iov->iov_len;
123 
124 			/*
125 			 * Make sure that all of the pages are currently
126 			 * resident so that we don't create any zero-fill
127 			 * pages.
128 			 */
129 			addr = trunc_page(v);
130 			eaddr = round_page(v + c);
131 
132 			if (addr < VM_MIN_KERNEL_ADDRESS) {
133 				error = EFAULT;
134 				goto ret;
135 			}
136 			for (; addr < eaddr; addr += PAGE_SIZE) {
137 				if (pmap_extract(kernel_pmap, addr) == 0) {
138 					error = EFAULT;
139 					goto ret;
140 				}
141 			}
142 			if (!kernacc((caddr_t)(long)v, c,
143 			    uio->uio_rw == UIO_READ ?
144 			    VM_PROT_READ : VM_PROT_WRITE)) {
145 				error = EFAULT;
146 				goto ret;
147 			}
148 
149 			error = uiomove((caddr_t)(long)v, (int)c, uio);
150 			continue;
151 		}
152 		/* else panic! */
153 	}
154 ret:
155 	curthread_pflags_restore(sflags);
156 	return (error);
157 }
158 
159 /*
160  * allow user processes to MMAP some memory sections
161  * instead of going through read/write
162  */
163 /* ARGSUSED */
164 int
165 memmmap(struct cdev *dev, vm_ooffset_t offset, vm_paddr_t *paddr,
166     int prot __unused, vm_memattr_t *memattr __unused)
167 {
168 	if (dev2unit(dev) == CDEV_MINOR_MEM)
169 		*paddr = offset;
170 	else if (dev2unit(dev) == CDEV_MINOR_KMEM)
171         	*paddr = vtophys(offset);
172 	/* else panic! */
173 	return (0);
174 }
175 
176 /*
177  * Operations for changing memory attributes.
178  *
179  * This is basically just an ioctl shim for mem_range_attr_get
180  * and mem_range_attr_set.
181  */
182 /* ARGSUSED */
183 int
184 memioctl(struct cdev *dev __unused, u_long cmd, caddr_t data, int flags,
185     struct thread *td)
186 {
187 	int nd, error = 0;
188 	struct mem_range_op *mo = (struct mem_range_op *)data;
189 	struct mem_range_desc *md;
190 
191 	/* is this for us? */
192 	if ((cmd != MEMRANGE_GET) &&
193 	    (cmd != MEMRANGE_SET))
194 		return (ENOTTY);
195 
196 	/* any chance we can handle this? */
197 	if (mem_range_softc.mr_op == NULL)
198 		return (EOPNOTSUPP);
199 
200 	/* do we have any descriptors? */
201 	if (mem_range_softc.mr_ndesc == 0)
202 		return (ENXIO);
203 
204 	switch (cmd) {
205 	case MEMRANGE_GET:
206 		nd = imin(mo->mo_arg[0], mem_range_softc.mr_ndesc);
207 		if (nd > 0) {
208 			md = (struct mem_range_desc *)
209 				malloc(nd * sizeof(struct mem_range_desc),
210 				       M_MEMDESC, M_WAITOK);
211 			error = mem_range_attr_get(md, &nd);
212 			if (!error)
213 				error = copyout(md, mo->mo_desc,
214 					nd * sizeof(struct mem_range_desc));
215 			free(md, M_MEMDESC);
216 		}
217 		else
218 			nd = mem_range_softc.mr_ndesc;
219 		mo->mo_arg[0] = nd;
220 		break;
221 
222 	case MEMRANGE_SET:
223 		md = (struct mem_range_desc *)malloc(sizeof(struct mem_range_desc),
224 						    M_MEMDESC, M_WAITOK);
225 		error = copyin(mo->mo_desc, md, sizeof(struct mem_range_desc));
226 		/* clamp description string */
227 		md->mr_owner[sizeof(md->mr_owner) - 1] = 0;
228 		if (error == 0)
229 			error = mem_range_attr_set(md, &mo->mo_arg[0]);
230 		free(md, M_MEMDESC);
231 		break;
232 	}
233 	return (error);
234 }
235