bsd/dev/i386/mem.c

   1 /*
   2  * Copyright (c) 2006 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 vm_offset_t kvtophys(vm_offset_t va);
  91 extern boolean_t kernacc(off_t, size_t );
  92
  93 static caddr_t devzerobuf;
  94
  95 int mmread(dev_t dev, struct uio *uio);
  96 int mmwrite(dev_t dev, struct uio *uio);
  97 int mmioctl(dev_t dev, u_long cmd, caddr_t data, int flag, struct proc *p);
  98 int mmrw(dev_t dev, struct uio *uio, enum uio_rw rw);
  99
 100 int
 101 mmread(dev_t dev, struct uio *uio)
 102 {
 103
 104         return (mmrw(dev, uio, UIO_READ));
 105 }
 106
 107 int
 108 mmwrite(dev_t dev, struct uio *uio)
 109 {
 110
 111         return (mmrw(dev, uio, UIO_WRITE));
 112 }
 113
 114 int
 115 mmioctl(__unused dev_t dev, u_long cmd, __unused caddr_t data,
 116                 __unused int flag, __unused struct proc *p)
 117 {
 118         switch (cmd) {
 119         case FIONBIO:
 120         case FIOASYNC:
 121                 /* OK to do nothing: we always return immediately */
 122                 break;
 123         default:
 124                 return ENODEV;
 125         }
 126
 127         return (0);
 128 }
 129
 130 int
 131 mmrw(dev_t dev, struct uio *uio, enum uio_rw rw)
 132 {
 133         register int o;
 134         register u_int c, v;
 135         int error = 0;
 136         vm_offset_t     where;
 137         vm_size_t size;
 138
 139         while (uio_resid(uio) > 0 && error == 0) {
 140                 if (uio_iov_len(uio) == 0) {
 141                         uio_next_iov(uio);
 142                         uio->uio_iovcnt--;
 143                         if (uio->uio_iovcnt < 0)
 144                                 panic("mmrw");
 145                         continue;
 146                 }
 147                 switch (minor(dev)) {
 148
 149                 /* minor device 0 is physical memory */
 150                 case 0:
 151                         v = trunc_page(uio->uio_offset);
 152                         if (uio->uio_offset >= mem_size)
 153                                 goto fault;
 154
 155                         size= PAGE_SIZE;
 156                         if (kmem_alloc(kernel_map, &where, size)
 157                                 != KERN_SUCCESS) {
 158                                 goto fault;
 159                         }
 160                         o = uio->uio_offset - v;
 161                         // LP64todo - fix this!
 162                         c = min(PAGE_SIZE - o, (u_int)uio_iov_len(uio));
 163                         error = uiomove((caddr_t) (where + o), c, uio);
 164                         kmem_free(kernel_map, where, PAGE_SIZE);
 165                         continue;
 166
 167                 /* minor device 1 is kernel memory */
 168                 case 1:
 169                         /* Do some sanity checking */
 170                         if (((vm_address_t)uio->uio_offset >= VM_MAX_KERNEL_ADDRESS) ||
 171                                 ((vm_address_t)uio->uio_offset <= VM_MIN_KERNEL_ADDRESS))
 172                                 goto fault;
 173                         c = uio_iov_len(uio);
 174                         if (!kernacc(uio->uio_offset, c))
 175                                 goto fault;
 176                         error = uiomove((caddr_t)(uintptr_t)uio->uio_offset,
 177                                         (int)c, uio);
 178                         continue;
 179
 180                 /* minor device 2 is EOF/RATHOLE */
 181                 case 2:
 182                         if (rw == UIO_READ)
 183                                 return (0);
 184                         c = uio_iov_len(uio);
 185                         break;
 186                 case 3:
 187                         if(devzerobuf == NULL) {
 188                                 MALLOC(devzerobuf, caddr_t,PAGE_SIZE, M_TEMP, M_WAITOK);
 189                                 bzero(devzerobuf, PAGE_SIZE);
 190                         }
 191                         if(uio->uio_rw == UIO_WRITE) {
 192                                 c = uio_iov_len(uio);
 193                                 break;
 194                         }
 195                         // LP64todo - fix this!
 196                         c = min(uio_iov_len(uio), PAGE_SIZE);
 197                         error = uiomove(devzerobuf, (int)c, uio);
 198                         continue;
 199                 default:
 200                         goto fault;
 201                         break;
 202                 }
 203
 204                 if (error)
 205                         break;
 206                 uio_iov_base_add(uio, c);
 207                 uio_iov_len_add(uio, -((int)c));
 208                 uio->uio_offset += c;
 209                 uio_setresid(uio, (uio_resid(uio) - c));
 210         }
 211         return (error);
 212 fault:
 213         return (EFAULT);
 214 }
 215
 216
 217 boolean_t
 218 kernacc(
 219     off_t       start,
 220     size_t      len
 221 )
 222 {
 223         off_t base;
 224         off_t end;
 225
 226         base = trunc_page(start);
 227         end = start + len;
 228
 229         while (base < end) {
 230           if(kvtophys((vm_offset_t)base) == 0ULL)
 231                         return(FALSE);
 232                 base += page_size;
 233         }
 234
 235         return (TRUE);
 236 }