osfmk/ipc/ipc_table.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
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  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,
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  25  * Please see the License for the specific language governing rights and
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  28  * @APPLE_LICENSE_OSREFERENCE_HEADER_END@
  29  */
  30 /*
  31  * @OSF_COPYRIGHT@
  32  */
  33 /*
  34  * Mach Operating System
  35  * Copyright (c) 1991,1990,1989 Carnegie Mellon University
  36  * All Rights Reserved.
  37  *
  38  * Permission to use, copy, modify and distribute this software and its
  39  * documentation is hereby granted, provided that both the copyright
  40  * notice and this permission notice appear in all copies of the
  41  * software, derivative works or modified versions, and any portions
  42  * thereof, and that both notices appear in supporting documentation.
  43  *
  44  * CARNEGIE MELLON ALLOWS FREE USE OF THIS SOFTWARE IN ITS "AS IS"
  45  * CONDITION.  CARNEGIE MELLON DISCLAIMS ANY LIABILITY OF ANY KIND FOR
  46  * ANY DAMAGES WHATSOEVER RESULTING FROM THE USE OF THIS SOFTWARE.
  47  *
  48  * Carnegie Mellon requests users of this software to return to
  49  *
  50  *  Software Distribution Coordinator  or  Software.Distribution@CS.CMU.EDU
  51  *  School of Computer Science
  52  *  Carnegie Mellon University
  53  *  Pittsburgh PA 15213-3890
  54  *
  55  * any improvements or extensions that they make and grant Carnegie Mellon
  56  * the rights to redistribute these changes.
  57  */
  58 /*
  59  */
  60 /*
  61  *      File:   ipc/ipc_table.c
  62  *      Author: Rich Draves
  63  *      Date:   1989
  64  *
  65  *      Functions to manipulate tables of IPC capabilities.
  66  */
  67
  68 #include <mach/kern_return.h>
  69 #include <mach/vm_param.h>
  70 #include <ipc/ipc_table.h>
  71 #include <ipc/ipc_port.h>
  72 #include <ipc/ipc_entry.h>
  73 #include <kern/kalloc.h>
  74 #include <vm/vm_kern.h>
  75
  76 /*
  77  * Forward declarations
  78  */
  79 void ipc_table_fill(
  80         ipc_table_size_t        its,
  81         unsigned int            num,
  82         unsigned int            min,
  83         vm_size_t               elemsize);
  84
  85 /*
  86  *      We borrow the kalloc map, rather than creating
  87  *      yet another submap of the kernel map.
  88  */
  89
  90 extern vm_map_t kalloc_map;
  91
  92 ipc_table_size_t ipc_table_entries;
  93 unsigned int ipc_table_entries_size = 512;
  94
  95 ipc_table_size_t ipc_table_dnrequests;
  96 unsigned int ipc_table_dnrequests_size = 64;
  97
  98 void
  99 ipc_table_fill(
 100         ipc_table_size_t        its,         /* array to fill */
 101         unsigned int            num,         /* size of array */
 102         unsigned int            min,         /* at least this many elements */
 103         vm_size_t               elemsize)    /* size of elements */
 104 {
 105         unsigned int index;
 106         vm_size_t minsize = min * elemsize;
 107         vm_size_t size;
 108         vm_size_t incrsize;
 109
 110         /* first use powers of two, up to the page size */
 111
 112         for (index = 0, size = 1;
 113              (index < num) && (size < PAGE_SIZE);
 114              size <<= 1) {
 115                 if (size >= minsize) {
 116                         its[index].its_size = size / elemsize;
 117                         index++;
 118                 }
 119         }
 120
 121         /* then increments of a page, then two pages, etc. */
 122
 123         for (incrsize = PAGE_SIZE; index < num;) {
 124                 unsigned int period;
 125
 126                 for (period = 0;
 127                      (period < 15) && (index < num);
 128                      period++, size += incrsize) {
 129                         if (size >= minsize) {
 130                                 its[index].its_size = size / elemsize;
 131                                 index++;
 132                         }
 133                 }
 134                 if (incrsize < (PAGE_SIZE << 3))
 135                         incrsize <<= 1;
 136         }
 137 }
 138
 139 void
 140 ipc_table_init(void)
 141 {
 142         ipc_table_entries = (ipc_table_size_t)
 143                 kalloc(sizeof(struct ipc_table_size) *
 144                        ipc_table_entries_size);
 145         assert(ipc_table_entries != ITS_NULL);
 146
 147         ipc_table_fill(ipc_table_entries, ipc_table_entries_size - 1,
 148                        16, sizeof(struct ipc_entry));
 149
 150         /* the last two elements should have the same size */
 151
 152         ipc_table_entries[ipc_table_entries_size - 1].its_size =
 153                 ipc_table_entries[ipc_table_entries_size - 2].its_size;
 154
 155
 156         ipc_table_dnrequests = (ipc_table_size_t)
 157                 kalloc(sizeof(struct ipc_table_size) *
 158                        ipc_table_dnrequests_size);
 159         assert(ipc_table_dnrequests != ITS_NULL);
 160
 161         ipc_table_fill(ipc_table_dnrequests, ipc_table_dnrequests_size - 1,
 162                        2, sizeof(struct ipc_port_request));
 163
 164         /* the last element should have zero size */
 165
 166         ipc_table_dnrequests[ipc_table_dnrequests_size - 1].its_size = 0;
 167 }
 168
 169 /*
 170  *      Routine:        ipc_table_alloc
 171  *      Purpose:
 172  *              Allocate a table.
 173  *      Conditions:
 174  *              May block.
 175  */
 176
 177 void *
 178 ipc_table_alloc(
 179         vm_size_t       size)
 180 {
 181         vm_offset_t table;
 182
 183         if (size < PAGE_SIZE)
 184                 return kalloc(size);
 185
 186         if (kmem_alloc(kalloc_map, &table, size) != KERN_SUCCESS)
 187                 table = 0;
 188
 189         return (void *)table;
 190 }
 191
 192 /*
 193  *      Routine:        ipc_table_realloc
 194  *      Purpose:
 195  *              Reallocate a big table.
 196  *
 197  *              The new table remaps the old table,
 198  *              so copying is not necessary.
 199  *      Conditions:
 200  *              Only works for page-size or bigger tables.
 201  *              May block.
 202  */
 203
 204 void *
 205 ipc_table_realloc(
 206         vm_size_t       old_size,
 207         void *          old_table,
 208         vm_size_t       new_size)
 209 {
 210         vm_offset_t new_table;
 211
 212         if (kmem_realloc(kalloc_map,
 213                          (vm_offset_t) old_table, old_size,
 214                          &new_table, new_size) != KERN_SUCCESS)
 215                 new_table = 0;
 216
 217         return (void *)new_table;
 218 }
 219
 220 /*
 221  *      Routine:        ipc_table_free
 222  *      Purpose:
 223  *              Free a table allocated with ipc_table_alloc or
 224  *              ipc_table_realloc.
 225  *      Conditions:
 226  *              May block.
 227  */
 228
 229 void
 230 ipc_table_free(
 231         vm_size_t       size,
 232         void *          table)
 233 {
 234         if (size < PAGE_SIZE)
 235                 kfree(table, size);
 236         else
 237                 kmem_free(kalloc_map, (vm_offset_t)table, size);
 238 }