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 vm_offset_t kvtophys(vm_offset_t va);
  83 extern boolean_t kernacc(off_t, size_t );
  84
  85 static caddr_t devzerobuf;
  86
  87 int mmread(dev_t dev, struct uio *uio);
  88 int mmwrite(dev_t dev, struct uio *uio);
  89 int mmioctl(dev_t dev, u_long cmd, caddr_t data, int flag, struct proc *p);
  90 int mmrw(dev_t dev, struct uio *uio, enum uio_rw rw);
  91
  92 int
  93 mmread(dev_t dev, struct uio *uio)
  94 {
  95
  96         return (mmrw(dev, uio, UIO_READ));
  97 }
  98
  99 int
 100 mmwrite(dev_t dev, struct uio *uio)
 101 {
 102
 103         return (mmrw(dev, uio, UIO_WRITE));
 104 }
 105
 106 int
 107 mmioctl(__unused dev_t dev, u_long cmd, __unused caddr_t data,
 108                 __unused int flag, __unused struct proc *p)
 109 {
 110         switch (cmd) {
 111         case FIONBIO:
 112         case FIOASYNC:
 113                 /* OK to do nothing: we always return immediately */
 114                 break;
 115         default:
 116                 return ENODEV;
 117         }
 118
 119         return (0);
 120 }
 121
 122 int
 123 mmrw(dev_t dev, struct uio *uio, enum uio_rw rw)
 124 {
 125         register int o;
 126         register u_int c, v;
 127         int error = 0;
 128         vm_offset_t     where;
 129         vm_size_t size;
 130
 131         while (uio_resid(uio) > 0 && error == 0) {
 132                 if (uio_iov_len(uio) == 0) {
 133                         uio_next_iov(uio);
 134                         uio->uio_iovcnt--;
 135                         if (uio->uio_iovcnt < 0)
 136                                 panic("mmrw");
 137                         continue;
 138                 }
 139                 switch (minor(dev)) {
 140
 141                 /* minor device 0 is physical memory */
 142                 case 0:
 143                         v = trunc_page(uio->uio_offset);
 144                         if (uio->uio_offset >= mem_size)
 145                                 goto fault;
 146
 147                         size= PAGE_SIZE;
 148                         if (kmem_alloc(kernel_map, &where, size)
 149                                 != KERN_SUCCESS) {
 150                                 goto fault;
 151                         }
 152                         o = uio->uio_offset - v;
 153                         // LP64todo - fix this!
 154                         c = min(PAGE_SIZE - o, (u_int)uio_iov_len(uio));
 155                         error = uiomove((caddr_t) (where + o), c, uio);
 156                         kmem_free(kernel_map, where, PAGE_SIZE);
 157                         continue;
 158
 159                 /* minor device 1 is kernel memory */
 160                 case 1:
 161                         /* Do some sanity checking */
 162                         if (((vm_address_t)uio->uio_offset >= VM_MAX_KERNEL_ADDRESS) ||
 163                                 ((vm_address_t)uio->uio_offset <= VM_MIN_KERNEL_ADDRESS))
 164                                 goto fault;
 165                         c = uio_iov_len(uio);
 166                         if (!kernacc(uio->uio_offset, c))
 167                                 goto fault;
 168                         error = uiomove((caddr_t)(uintptr_t)uio->uio_offset,
 169                                         (int)c, uio);
 170                         continue;
 171
 172                 /* minor device 2 is EOF/RATHOLE */
 173                 case 2:
 174                         if (rw == UIO_READ)
 175                                 return (0);
 176                         c = uio_iov_len(uio);
 177                         break;
 178                 case 3:
 179                         if(devzerobuf == NULL) {
 180                                 MALLOC(devzerobuf, caddr_t,PAGE_SIZE, M_TEMP, M_WAITOK);
 181                                 bzero(devzerobuf, PAGE_SIZE);
 182                         }
 183                         if(uio->uio_rw == UIO_WRITE) {
 184                                 c = uio_iov_len(uio);
 185                                 break;
 186                         }
 187                         // LP64todo - fix this!
 188                         c = min(uio_iov_len(uio), PAGE_SIZE);
 189                         error = uiomove(devzerobuf, (int)c, uio);
 190                         continue;
 191                 default:
 192                         goto fault;
 193                         break;
 194                 }
 195
 196                 if (error)
 197                         break;
 198                 uio_iov_base_add(uio, c);
 199                 uio_iov_len_add(uio, -((int)c));
 200                 uio->uio_offset += c;
 201                 uio_setresid(uio, (uio_resid(uio) - c));
 202         }
 203         return (error);
 204 fault:
 205         return (EFAULT);
 206 }
 207
 208
 209 boolean_t
 210 kernacc(
 211     off_t       start,
 212     size_t      len
 213 )
 214 {
 215         off_t base;
 216         off_t end;
 217
 218         base = trunc_page(start);
 219         end = start + len;
 220
 221         while (base < end) {
 222           if(kvtophys((vm_offset_t)base) == 0ULL)
 223                         return(FALSE);
 224                 base += page_size;
 225         }
 226
 227         return (TRUE);
 228 }