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  * The contents of this file constitute Original Code as defined in and
   7  * are subject to the Apple Public Source License Version 1.1 (the
   8  * "License").  You may not use this file except in compliance with the
   9  * License.  Please obtain a copy of the License at
  10  * http://www.apple.com/publicsource and read it before using this file.
  11  *
  12  * This Original Code and all software distributed under the License are
  13  * distributed on an "AS IS" basis, WITHOUT WARRANTY OF ANY KIND, EITHER
  14  * EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES,
  15  * INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY,
  16  * FITNESS FOR A PARTICULAR PURPOSE OR NON-INFRINGEMENT.  Please see the
  17  * License for the specific language governing rights and limitations
  18  * under the License.
  19  *
  20  * @APPLE_LICENSE_HEADER_END@
  21  */
  22 /*-
  23  * Copyright (c) 1988 University of Utah.
  24  * Copyright (c) 1982, 1986, 1990, 1993
  25  *      The Regents of the University of California.  All rights reserved.
  26  *
  27  * This code is derived from software contributed to Berkeley by
  28  * the Systems Programming Group of the University of Utah Computer
  29  * Science Department, and code derived from software contributed to
  30  * Berkeley by William Jolitz.
  31  *
  32  * Redistribution and use in source and binary forms, with or without
  33  * modification, are permitted provided that the following conditions
  34  * are met:
  35  * 1. Redistributions of source code must retain the above copyright
  36  *    notice, this list of conditions and the following disclaimer.
  37  * 2. Redistributions in binary form must reproduce the above copyright
  38  *    notice, this list of conditions and the following disclaimer in the
  39  *    documentation and/or other materials provided with the distribution.
  40  * 3. All advertising materials mentioning features or use of this software
  41  *    must display the following acknowledgement:
  42  *      This product includes software developed by the University of
  43  *      California, Berkeley and its contributors.
  44  * 4. Neither the name of the University nor the names of its contributors
  45  *    may be used to endorse or promote products derived from this software
  46  *    without specific prior written permission.
  47  *
  48  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
  49  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  50  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  51  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
  52  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  53  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  54  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  55  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  56  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  57  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  58  * SUCH DAMAGE.
  59  *
  60  * from: Utah $Hdr: mem.c 1.13 89/10/08$
  61  *      @(#)mem.c       8.1 (Berkeley) 6/11/93
  62  */
  63
  64 #include <mach_load.h>
  65
  66 /*
  67  * Memory special file
  68  */
  69
  70 #include <sys/param.h>
  71 #include <sys/dir.h>
  72 #include <sys/proc.h>
  73 #include <sys/systm.h>
  74 #include <sys/vm.h>
  75 #include <sys/uio_internal.h>
  76 #include <sys/malloc.h>
  77
  78 #include <mach/vm_types.h>
  79 #include <mach/vm_param.h>
  80 #include <vm/vm_kern.h>         /* for kernel_map */
  81
  82 extern addr64_t  kvtophys(vm_offset_t va);
  83 extern boolean_t kernacc(off_t, size_t );
  84 extern int setup_kmem;
  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(dev_t dev, u_long cmd, __unused caddr_t data,
 109                 __unused int flag, __unused struct proc *p)
 110 {
 111         int minnum = minor(dev);
 112
 113         if ((setup_kmem == 0) && ((minnum == 0) || (minnum == 1)))
 114                 return(EINVAL);
 115
 116         switch (cmd) {
 117         case FIONBIO:
 118         case FIOASYNC:
 119                 /* OK to do nothing: we always return immediately */
 120                 break;
 121         default:
 122                 return ENODEV;
 123         }
 124
 125         return (0);
 126 }
 127
 128 int
 129 mmrw(dev_t dev, struct uio *uio, enum uio_rw rw)
 130 {
 131         register int o;
 132         register u_int c, v;
 133         int error = 0;
 134         vm_offset_t     where;
 135         vm_size_t size;
 136
 137
 138         while (uio_resid(uio) > 0 && error == 0) {
 139                 if (uio_iov_len(uio) == 0) {
 140                         uio_next_iov(uio);
 141                         uio->uio_iovcnt--;
 142                         if (uio->uio_iovcnt < 0)
 143                                 panic("mmrw");
 144                         continue;
 145                 }
 146                 switch (minor(dev)) {
 147
 148                 /* minor device 0 is physical memory */
 149                 case 0:
 150                         if (setup_kmem == 0)
 151                                 return(ENODEV);
 152
 153                         v = trunc_page(uio->uio_offset);
 154                         if (uio->uio_offset >= mem_size)
 155                                 goto fault;
 156
 157                         size= PAGE_SIZE;
 158                         if (kmem_alloc(kernel_map, &where, size)
 159                                 != KERN_SUCCESS) {
 160                                 goto fault;
 161                         }
 162                         o = uio->uio_offset - v;
 163                         // LP64todo - fix this!
 164                         c = min(PAGE_SIZE - o, (u_int)uio_iov_len(uio));
 165                         error = uiomove((caddr_t) (where + o), c, uio);
 166                         kmem_free(kernel_map, where, PAGE_SIZE);
 167                         continue;
 168
 169                 /* minor device 1 is kernel memory */
 170                 case 1:
 171                         if (setup_kmem == 0)
 172                                 return(ENODEV);
 173                         /* Do some sanity checking */
 174                         if (((vm_address_t)uio->uio_offset >= VM_MAX_KERNEL_ADDRESS) ||
 175                                 ((vm_address_t)uio->uio_offset <= VM_MIN_KERNEL_ADDRESS))
 176                                 goto fault;
 177                         c = uio_iov_len(uio);
 178                         if (!kernacc(uio->uio_offset, c))
 179                                 goto fault;
 180                         error = uiomove((caddr_t)(uintptr_t)uio->uio_offset,
 181                                         (int)c, uio);
 182                         continue;
 183
 184                 /* minor device 2 is EOF/RATHOLE */
 185                 case 2:
 186                         if (rw == UIO_READ)
 187                                 return (0);
 188                         c = uio_iov_len(uio);
 189                         break;
 190                 case 3:
 191                         if(devzerobuf == NULL) {
 192                                 MALLOC(devzerobuf, caddr_t,PAGE_SIZE, M_TEMP, M_WAITOK);
 193                                 bzero(devzerobuf, PAGE_SIZE);
 194                         }
 195                         if(uio->uio_rw == UIO_WRITE) {
 196                                 c = uio_iov_len(uio);
 197                                 break;
 198                         }
 199                         // LP64todo - fix this!
 200                         c = min(uio_iov_len(uio), PAGE_SIZE);
 201                         error = uiomove(devzerobuf, (int)c, uio);
 202                         continue;
 203                 default:
 204                         goto fault;
 205                         break;
 206                 }
 207
 208                 if (error)
 209                         break;
 210                 uio_iov_base_add(uio, c);
 211                 uio_iov_len_add(uio, -((int)c));
 212                 uio->uio_offset += c;
 213                 uio_setresid(uio, (uio_resid(uio) - c));
 214         }
 215         return (error);
 216 fault:
 217         return (EFAULT);
 218 }
 219
 220
 221 boolean_t
 222 kernacc(
 223     off_t       start,
 224     size_t      len
 225 )
 226 {
 227         off_t base;
 228         off_t end;
 229
 230         base = trunc_page(start);
 231         end = start + len;
 232
 233         while (base < end) {
 234           if(kvtophys((vm_offset_t)base) == 0ULL)
 235                         return(FALSE);
 236                 base += page_size;
 237         }
 238
 239         return (TRUE);
 240 }