bsd/dev/i386/mem.c

   1 /*
   2  * Copyright (c) 2000-2004 Apple Computer, Inc. All rights reserved.
   3  *
   4  * @APPLE_LICENSE_HEADER_START@
   5  *
   6  * This file contains Original Code and/or Modifications of Original Code
   7  * as defined in and that are subject to the Apple Public Source License
   8  * Version 2.0 (the 'License'). You may not use this file except in
   9  * compliance with the License. Please obtain a copy of the License at
  10  * http://www.opensource.apple.com/apsl/ and read it before using this
  11  * file.
  12  *
  13  * The Original Code and all software distributed under the License are
  14  * distributed on an 'AS IS' basis, WITHOUT WARRANTY OF ANY KIND, EITHER
  15  * EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES,
  16  * INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY,
  17  * FITNESS FOR A PARTICULAR PURPOSE, QUIET ENJOYMENT OR NON-INFRINGEMENT.
  18  * Please see the License for the specific language governing rights and
  19  * limitations under the License.
  20  *
  21  * @APPLE_LICENSE_HEADER_END@
  22  */
  23 /*-
  24  * Copyright (c) 1988 University of Utah.
  25  * Copyright (c) 1982, 1986, 1990, 1993
  26  *      The Regents of the University of California.  All rights reserved.
  27  *
  28  * This code is derived from software contributed to Berkeley by
  29  * the Systems Programming Group of the University of Utah Computer
  30  * Science Department, and code derived from software contributed to
  31  * Berkeley by William Jolitz.
  32  *
  33  * Redistribution and use in source and binary forms, with or without
  34  * modification, are permitted provided that the following conditions
  35  * are met:
  36  * 1. Redistributions of source code must retain the above copyright
  37  *    notice, this list of conditions and the following disclaimer.
  38  * 2. Redistributions in binary form must reproduce the above copyright
  39  *    notice, this list of conditions and the following disclaimer in the
  40  *    documentation and/or other materials provided with the distribution.
  41  * 3. All advertising materials mentioning features or use of this software
  42  *    must display the following acknowledgement:
  43  *      This product includes software developed by the University of
  44  *      California, Berkeley and its contributors.
  45  * 4. Neither the name of the University nor the names of its contributors
  46  *    may be used to endorse or promote products derived from this software
  47  *    without specific prior written permission.
  48  *
  49  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
  50  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  51  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  52  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
  53  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  54  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  55  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  56  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  57  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  58  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  59  * SUCH DAMAGE.
  60  *
  61  * from: Utah $Hdr: mem.c 1.13 89/10/08$
  62  *      @(#)mem.c       8.1 (Berkeley) 6/11/93
  63  */
  64
  65 #include <mach_load.h>
  66
  67 /*
  68  * Memory special file
  69  */
  70
  71 #include <sys/param.h>
  72 #include <sys/dir.h>
  73 #include <sys/proc.h>
  74 #include <sys/systm.h>
  75 #include <sys/vm.h>
  76 #include <sys/uio_internal.h>
  77 #include <sys/malloc.h>
  78
  79 #include <mach/vm_types.h>
  80 #include <mach/vm_param.h>
  81 #include <vm/vm_kern.h>         /* for kernel_map */
  82
  83 extern vm_offset_t kvtophys(vm_offset_t va);
  84 extern boolean_t kernacc(off_t, size_t );
  85
  86 static caddr_t devzerobuf;
  87
  88 int mmread(dev_t dev, struct uio *uio);
  89 int mmwrite(dev_t dev, struct uio *uio);
  90 int mmioctl(dev_t dev, u_long cmd, caddr_t data, int flag, struct proc *p);
  91 int mmrw(dev_t dev, struct uio *uio, enum uio_rw rw);
  92
  93 int
  94 mmread(dev_t dev, struct uio *uio)
  95 {
  96
  97         return (mmrw(dev, uio, UIO_READ));
  98 }
  99
 100 int
 101 mmwrite(dev_t dev, struct uio *uio)
 102 {
 103
 104         return (mmrw(dev, uio, UIO_WRITE));
 105 }
 106
 107 int
 108 mmioctl(__unused dev_t dev, u_long cmd, __unused caddr_t data,
 109                 __unused int flag, __unused struct proc *p)
 110 {
 111         switch (cmd) {
 112         case FIONBIO:
 113         case FIOASYNC:
 114                 /* OK to do nothing: we always return immediately */
 115                 break;
 116         default:
 117                 return ENODEV;
 118         }
 119
 120         return (0);
 121 }
 122
 123 int
 124 mmrw(dev_t dev, struct uio *uio, enum uio_rw rw)
 125 {
 126         register int o;
 127         register u_int c, v;
 128         int error = 0;
 129         vm_offset_t     where;
 130         vm_size_t size;
 131
 132         while (uio_resid(uio) > 0 && error == 0) {
 133                 if (uio_iov_len(uio) == 0) {
 134                         uio_next_iov(uio);
 135                         uio->uio_iovcnt--;
 136                         if (uio->uio_iovcnt < 0)
 137                                 panic("mmrw");
 138                         continue;
 139                 }
 140                 switch (minor(dev)) {
 141
 142                 /* minor device 0 is physical memory */
 143                 case 0:
 144                         v = trunc_page(uio->uio_offset);
 145                         if (uio->uio_offset >= mem_size)
 146                                 goto fault;
 147
 148                         size= PAGE_SIZE;
 149                         if (kmem_alloc(kernel_map, &where, size)
 150                                 != KERN_SUCCESS) {
 151                                 goto fault;
 152                         }
 153                         o = uio->uio_offset - v;
 154                         // LP64todo - fix this!
 155                         c = min(PAGE_SIZE - o, (u_int)uio_iov_len(uio));
 156                         error = uiomove((caddr_t) (where + o), c, uio);
 157                         kmem_free(kernel_map, where, PAGE_SIZE);
 158                         continue;
 159
 160                 /* minor device 1 is kernel memory */
 161                 case 1:
 162                         /* Do some sanity checking */
 163                         if (((vm_address_t)uio->uio_offset >= VM_MAX_KERNEL_ADDRESS) ||
 164                                 ((vm_address_t)uio->uio_offset <= VM_MIN_KERNEL_ADDRESS))
 165                                 goto fault;
 166                         c = uio_iov_len(uio);
 167                         if (!kernacc(uio->uio_offset, c))
 168                                 goto fault;
 169                         error = uiomove((caddr_t)(uintptr_t)uio->uio_offset,
 170                                         (int)c, uio);
 171                         continue;
 172
 173                 /* minor device 2 is EOF/RATHOLE */
 174                 case 2:
 175                         if (rw == UIO_READ)
 176                                 return (0);
 177                         c = uio_iov_len(uio);
 178                         break;
 179                 case 3:
 180                         if(devzerobuf == NULL) {
 181                                 MALLOC(devzerobuf, caddr_t,PAGE_SIZE, M_TEMP, M_WAITOK);
 182                                 bzero(devzerobuf, PAGE_SIZE);
 183                         }
 184                         if(uio->uio_rw == UIO_WRITE) {
 185                                 c = uio_iov_len(uio);
 186                                 break;
 187                         }
 188                         // LP64todo - fix this!
 189                         c = min(uio_iov_len(uio), PAGE_SIZE);
 190                         error = uiomove(devzerobuf, (int)c, uio);
 191                         continue;
 192                 default:
 193                         goto fault;
 194                         break;
 195                 }
 196
 197                 if (error)
 198                         break;
 199                 uio_iov_base_add(uio, c);
 200                 uio_iov_len_add(uio, -((int)c));
 201                 uio->uio_offset += c;
 202                 uio_setresid(uio, (uio_resid(uio) - c));
 203         }
 204         return (error);
 205 fault:
 206         return (EFAULT);
 207 }
 208
 209
 210 boolean_t
 211 kernacc(
 212     off_t       start,
 213     size_t      len
 214 )
 215 {
 216         off_t base;
 217         off_t end;
 218
 219         base = trunc_page(start);
 220         end = start + len;
 221
 222         while (base < end) {
 223           if(kvtophys((vm_offset_t)base) == 0ULL)
 224                         return(FALSE);
 225                 base += page_size;
 226         }
 227
 228         return (TRUE);
 229 }