bsd/dev/i386/mem.c

   1 /*
   2  * Copyright (c) 2000-2004 Apple Computer, Inc. All rights reserved.
   3  *
   4  * @APPLE_LICENSE_OSREFERENCE_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.  The rights granted to you under the
  10  * License may not be used to create, or enable the creation or
  11  * redistribution of, unlawful or unlicensed copies of an Apple operating
  12  * system, or to circumvent, violate, or enable the circumvention or
  13  * violation of, any terms of an Apple operating system software license
  14  * agreement.
  15  *
  16  * Please obtain a copy of the License at
  17  * http://www.opensource.apple.com/apsl/ and read it before using this
  18  * file.
  19  *
  20  * The Original Code and all software distributed under the License are
  21  * distributed on an 'AS IS' basis, WITHOUT WARRANTY OF ANY KIND, EITHER
  22  * EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES,
  23  * INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY,
  24  * FITNESS FOR A PARTICULAR PURPOSE, QUIET ENJOYMENT OR NON-INFRINGEMENT.
  25  * Please see the License for the specific language governing rights and
  26  * limitations under the License.
  27  *
  28  * @APPLE_LICENSE_OSREFERENCE_HEADER_END@
  29  */
  30 /*-
  31  * Copyright (c) 1988 University of Utah.
  32  * Copyright (c) 1982, 1986, 1990, 1993
  33  *      The Regents of the University of California.  All rights reserved.
  34  *
  35  * This code is derived from software contributed to Berkeley by
  36  * the Systems Programming Group of the University of Utah Computer
  37  * Science Department, and code derived from software contributed to
  38  * Berkeley by William Jolitz.
  39  *
  40  * Redistribution and use in source and binary forms, with or without
  41  * modification, are permitted provided that the following conditions
  42  * are met:
  43  * 1. Redistributions of source code must retain the above copyright
  44  *    notice, this list of conditions and the following disclaimer.
  45  * 2. Redistributions in binary form must reproduce the above copyright
  46  *    notice, this list of conditions and the following disclaimer in the
  47  *    documentation and/or other materials provided with the distribution.
  48  * 3. All advertising materials mentioning features or use of this software
  49  *    must display the following acknowledgement:
  50  *      This product includes software developed by the University of
  51  *      California, Berkeley and its contributors.
  52  * 4. Neither the name of the University nor the names of its contributors
  53  *    may be used to endorse or promote products derived from this software
  54  *    without specific prior written permission.
  55  *
  56  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
  57  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  58  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  59  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
  60  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  61  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  62  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  63  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  64  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  65  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  66  * SUCH DAMAGE.
  67  *
  68  * from: Utah $Hdr: mem.c 1.13 89/10/08$
  69  *      @(#)mem.c       8.1 (Berkeley) 6/11/93
  70  */
  71
  72 #include <mach_load.h>
  73
  74 /*
  75  * Memory special file
  76  */
  77
  78 #include <sys/param.h>
  79 #include <sys/dir.h>
  80 #include <sys/proc.h>
  81 #include <sys/systm.h>
  82 #include <sys/vm.h>
  83 #include <sys/uio_internal.h>
  84 #include <sys/malloc.h>
  85
  86 #include <mach/vm_types.h>
  87 #include <mach/vm_param.h>
  88 #include <vm/vm_kern.h>         /* for kernel_map */
  89
  90 extern addr64_t  kvtophys(vm_offset_t va);
  91 extern boolean_t kernacc(off_t, size_t );
  92 extern int setup_kmem;
  93
  94 static caddr_t devzerobuf;
  95
  96 int mmread(dev_t dev, struct uio *uio);
  97 int mmwrite(dev_t dev, struct uio *uio);
  98 int mmioctl(dev_t dev, u_long cmd, caddr_t data, int flag, struct proc *p);
  99 int mmrw(dev_t dev, struct uio *uio, enum uio_rw rw);
 100
 101 int
 102 mmread(dev_t dev, struct uio *uio)
 103 {
 104
 105         return (mmrw(dev, uio, UIO_READ));
 106 }
 107
 108 int
 109 mmwrite(dev_t dev, struct uio *uio)
 110 {
 111
 112         return (mmrw(dev, uio, UIO_WRITE));
 113 }
 114
 115 int
 116 mmioctl(dev_t dev, u_long cmd, __unused caddr_t data,
 117                 __unused int flag, __unused struct proc *p)
 118 {
 119         int minnum = minor(dev);
 120
 121         if ((setup_kmem == 0) && ((minnum == 0) || (minnum == 1)))
 122                 return(EINVAL);
 123
 124         switch (cmd) {
 125         case FIONBIO:
 126         case FIOASYNC:
 127                 /* OK to do nothing: we always return immediately */
 128                 break;
 129         default:
 130                 return ENODEV;
 131         }
 132
 133         return (0);
 134 }
 135
 136 int
 137 mmrw(dev_t dev, struct uio *uio, enum uio_rw rw)
 138 {
 139         register int o;
 140         register u_int c, v;
 141         int error = 0;
 142         vm_offset_t     where;
 143         vm_size_t size;
 144
 145
 146         while (uio_resid(uio) > 0 && error == 0) {
 147                 if (uio_iov_len(uio) == 0) {
 148                         uio_next_iov(uio);
 149                         uio->uio_iovcnt--;
 150                         if (uio->uio_iovcnt < 0)
 151                                 panic("mmrw");
 152                         continue;
 153                 }
 154                 switch (minor(dev)) {
 155
 156                 /* minor device 0 is physical memory */
 157                 case 0:
 158                         if (setup_kmem == 0)
 159                                 return(ENODEV);
 160
 161                         v = trunc_page(uio->uio_offset);
 162                         if (uio->uio_offset >= mem_size)
 163                                 goto fault;
 164
 165                         size= PAGE_SIZE;
 166                         if (kmem_alloc(kernel_map, &where, size)
 167                                 != KERN_SUCCESS) {
 168                                 goto fault;
 169                         }
 170                         o = uio->uio_offset - v;
 171                         // LP64todo - fix this!
 172                         c = min(PAGE_SIZE - o, (u_int)uio_iov_len(uio));
 173                         error = uiomove((caddr_t) (where + o), c, uio);
 174                         kmem_free(kernel_map, where, PAGE_SIZE);
 175                         continue;
 176
 177                 /* minor device 1 is kernel memory */
 178                 case 1:
 179                         if (setup_kmem == 0)
 180                                 return(ENODEV);
 181                         /* Do some sanity checking */
 182                         if (((vm_address_t)uio->uio_offset >= VM_MAX_KERNEL_ADDRESS) ||
 183                                 ((vm_address_t)uio->uio_offset <= VM_MIN_KERNEL_ADDRESS))
 184                                 goto fault;
 185                         c = uio_iov_len(uio);
 186                         if (!kernacc(uio->uio_offset, c))
 187                                 goto fault;
 188                         error = uiomove((caddr_t)(uintptr_t)uio->uio_offset,
 189                                         (int)c, uio);
 190                         continue;
 191
 192                 /* minor device 2 is EOF/RATHOLE */
 193                 case 2:
 194                         if (rw == UIO_READ)
 195                                 return (0);
 196                         c = uio_iov_len(uio);
 197                         break;
 198                 case 3:
 199                         if(devzerobuf == NULL) {
 200                                 MALLOC(devzerobuf, caddr_t,PAGE_SIZE, M_TEMP, M_WAITOK);
 201                                 bzero(devzerobuf, PAGE_SIZE);
 202                         }
 203                         if(uio->uio_rw == UIO_WRITE) {
 204                                 c = uio_iov_len(uio);
 205                                 break;
 206                         }
 207                         // LP64todo - fix this!
 208                         c = min(uio_iov_len(uio), PAGE_SIZE);
 209                         error = uiomove(devzerobuf, (int)c, uio);
 210                         continue;
 211                 default:
 212                         goto fault;
 213                         break;
 214                 }
 215
 216                 if (error)
 217                         break;
 218                 uio_iov_base_add(uio, c);
 219                 uio_iov_len_add(uio, -((int)c));
 220                 uio->uio_offset += c;
 221                 uio_setresid(uio, (uio_resid(uio) - c));
 222         }
 223         return (error);
 224 fault:
 225         return (EFAULT);
 226 }
 227
 228
 229 boolean_t
 230 kernacc(
 231     off_t       start,
 232     size_t      len
 233 )
 234 {
 235         off_t base;
 236         off_t end;
 237
 238         base = trunc_page(start);
 239         end = start + len;
 240
 241         while (base < end) {
 242           if(kvtophys((vm_offset_t)base) == 0ULL)
 243                         return(FALSE);
 244                 base += page_size;
 245         }
 246
 247         return (TRUE);
 248 }