osfmk/ipc/ipc_table.c

   1 /*
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  13  * terms of an Apple operating system software license agreement.
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  15  * Please obtain a copy of the License at
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  17  *
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  28 /*
  29  * @OSF_COPYRIGHT@
  30  */
  31 /*
  32  * Mach Operating System
  33  * Copyright (c) 1991,1990,1989 Carnegie Mellon University
  34  * All Rights Reserved.
  35  *
  36  * Permission to use, copy, modify and distribute this software and its
  37  * documentation is hereby granted, provided that both the copyright
  38  * notice and this permission notice appear in all copies of the
  39  * software, derivative works or modified versions, and any portions
  40  * thereof, and that both notices appear in supporting documentation.
  41  *
  42  * CARNEGIE MELLON ALLOWS FREE USE OF THIS SOFTWARE IN ITS "AS IS"
  43  * CONDITION.  CARNEGIE MELLON DISCLAIMS ANY LIABILITY OF ANY KIND FOR
  44  * ANY DAMAGES WHATSOEVER RESULTING FROM THE USE OF THIS SOFTWARE.
  45  *
  46  * Carnegie Mellon requests users of this software to return to
  47  *
  48  *  Software Distribution Coordinator  or  Software.Distribution@CS.CMU.EDU
  49  *  School of Computer Science
  50  *  Carnegie Mellon University
  51  *  Pittsburgh PA 15213-3890
  52  *
  53  * any improvements or extensions that they make and grant Carnegie Mellon
  54  * the rights to redistribute these changes.
  55  */
  56 /*
  57  */
  58 /*
  59  *      File:   ipc/ipc_table.c
  60  *      Author: Rich Draves
  61  *      Date:   1989
  62  *
  63  *      Functions to manipulate tables of IPC capabilities.
  64  */
  65
  66 #include <mach/kern_return.h>
  67 #include <mach/vm_param.h>
  68 #include <ipc/ipc_table.h>
  69 #include <ipc/ipc_port.h>
  70 #include <ipc/ipc_entry.h>
  71 #include <kern/kalloc.h>
  72 #include <vm/vm_kern.h>
  73
  74 /*
  75  * Forward declarations
  76  */
  77 void ipc_table_fill(
  78         ipc_table_size_t        its,
  79         unsigned int            num,
  80         unsigned int            min,
  81         vm_size_t               elemsize);
  82
  83 /*
  84  *      We borrow the kalloc map, rather than creating
  85  *      yet another submap of the kernel map.
  86  */
  87
  88 extern vm_map_t kalloc_map;
  89
  90 ipc_table_size_t ipc_table_entries;
  91 unsigned int ipc_table_entries_size = 512;
  92
  93 ipc_table_size_t ipc_table_dnrequests;
  94 unsigned int ipc_table_dnrequests_size = 64;
  95
  96 void
  97 ipc_table_fill(
  98         ipc_table_size_t        its,         /* array to fill */
  99         unsigned int            num,         /* size of array */
 100         unsigned int            min,         /* at least this many elements */
 101         vm_size_t               elemsize)    /* size of elements */
 102 {
 103         unsigned int index;
 104         vm_size_t minsize = min * elemsize;
 105         vm_size_t size;
 106         vm_size_t incrsize;
 107
 108         /* first use powers of two, up to the page size */
 109
 110         for (index = 0, size = 1;
 111              (index < num) && (size < PAGE_SIZE);
 112              size <<= 1) {
 113                 if (size >= minsize) {
 114                         its[index].its_size = (ipc_table_elems_t)(size / elemsize);
 115                         index++;
 116                 }
 117         }
 118
 119         /* then increments of a page, then two pages, etc. */
 120
 121         for (incrsize = PAGE_SIZE; index < num;) {
 122                 unsigned int period;
 123
 124                 for (period = 0;
 125                      (period < 15) && (index < num);
 126                      period++, size += incrsize) {
 127                         if (size >= minsize) {
 128                                 its[index].its_size = (ipc_table_elems_t)(size / elemsize);
 129                                 index++;
 130                         }
 131                 }
 132                 if (incrsize < (PAGE_SIZE << 3))
 133                         incrsize <<= 1;
 134         }
 135 }
 136
 137 void
 138 ipc_table_init(void)
 139 {
 140         ipc_table_entries = (ipc_table_size_t)
 141                 kalloc(sizeof(struct ipc_table_size) *
 142                        ipc_table_entries_size);
 143         assert(ipc_table_entries != ITS_NULL);
 144
 145         ipc_table_fill(ipc_table_entries, ipc_table_entries_size - 1,
 146                        16, sizeof(struct ipc_entry));
 147
 148         /* the last two elements should have the same size */
 149
 150         ipc_table_entries[ipc_table_entries_size - 1].its_size =
 151                 ipc_table_entries[ipc_table_entries_size - 2].its_size;
 152
 153
 154         ipc_table_dnrequests = (ipc_table_size_t)
 155                 kalloc(sizeof(struct ipc_table_size) *
 156                        ipc_table_dnrequests_size);
 157         assert(ipc_table_dnrequests != ITS_NULL);
 158
 159         ipc_table_fill(ipc_table_dnrequests, ipc_table_dnrequests_size - 1,
 160                        2, sizeof(struct ipc_port_request));
 161
 162         /* the last element should have zero size */
 163
 164         ipc_table_dnrequests[ipc_table_dnrequests_size - 1].its_size = 0;
 165 }
 166
 167 /*
 168  *      Routine:        ipc_table_alloc
 169  *      Purpose:
 170  *              Allocate a table.
 171  *      Conditions:
 172  *              May block.
 173  */
 174
 175 void *
 176 ipc_table_alloc(
 177         vm_size_t       size)
 178 {
 179         vm_offset_t table;
 180
 181         if (size < PAGE_SIZE)
 182                 return kalloc(size);
 183
 184         if (kmem_alloc(kalloc_map, &table, size) != KERN_SUCCESS)
 185                 table = 0;
 186
 187         return (void *)table;
 188 }
 189
 190 /*
 191  *      Routine:        ipc_table_realloc
 192  *      Purpose:
 193  *              Reallocate a big table.
 194  *
 195  *              The new table remaps the old table,
 196  *              so copying is not necessary.
 197  *      Conditions:
 198  *              Only works for page-size or bigger tables.
 199  *              May block.
 200  */
 201
 202 void *
 203 ipc_table_realloc(
 204         vm_size_t       old_size,
 205         void *          old_table,
 206         vm_size_t       new_size)
 207 {
 208         vm_offset_t new_table;
 209
 210         if (kmem_realloc(kalloc_map,
 211                          (vm_offset_t) old_table, old_size,
 212                          &new_table, new_size) != KERN_SUCCESS)
 213                 new_table = 0;
 214
 215         return (void *)new_table;
 216 }
 217
 218 /*
 219  *      Routine:        ipc_table_free
 220  *      Purpose:
 221  *              Free a table allocated with ipc_table_alloc or
 222  *              ipc_table_realloc.
 223  *      Conditions:
 224  *              May block.
 225  */
 226
 227 void
 228 ipc_table_free(
 229         vm_size_t       size,
 230         void *          table)
 231 {
 232         if (size < PAGE_SIZE)
 233                 kfree(table, size);
 234         else
 235                 kmem_free(kalloc_map, (vm_offset_t)table, size);
 236 }