sim/ppc/hw_shm.c

   1 /*  This file is part of the program psim.
   2
   3     Copyright (C) 1997,2008, Joel Sherrill <joel@OARcorp.com>
   4
   5     This program is free software; you can redistribute it and/or modify
   6     it under the terms of the GNU General Public License as published by
   7     the Free Software Foundation; either version 3 of the License, or
   8     (at your option) any later version.
   9
  10     This program is distributed in the hope that it will be useful,
  11     but WITHOUT ANY WARRANTY; without even the implied warranty of
  12     MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  13     GNU General Public License for more details.
  14
  15     You should have received a copy of the GNU General Public License
  16     along with this program; if not, see <http://www.gnu.org/licenses/>.
  17
  18     */
  19
  20
  21 #ifndef _HW_SHM_C_
  22 #define _HW_SHM_C_
  23
  24 #include "device_table.h"
  25
  26 #include <string.h>
  27 #include <sys/ipc.h>
  28 #include <sys/shm.h>
  29
  30
  31 /* DEVICE
  32
  33
  34    shm - map unix shared memory into psim address space
  35
  36
  37    DESCRIPTION
  38
  39
  40    This device implements an area of memory which is mapped into UNIX
  41    shared memory.
  42
  43
  44    PROPERTIES
  45
  46
  47    reg = <address> <size> (required)
  48
  49    Determine where the memory lives in the parents address space.
  50    The SHM area is assumed to be of the same length.
  51
  52    key = <integer> (required)
  53
  54    This is the key of the unix shared memory area.
  55
  56    EXAMPLES
  57
  58
  59    Enable tracing of the shm:
  60
  61    |  bash$ psim -t shm-device \
  62
  63
  64    Configure a 512 kilobytes of UNIX shared memory with the key 0x12345678
  65    mapped into psim address space at 0x0c000000.
  66
  67    |  -o '/shm@0x0c000000/reg 0x0c000000 0x80000' \
  68    |  -o '/shm@0x0c000000/key 0x12345678' \
  69
  70    sim/ppc/run -o '/#address-cells 1' \
  71          -o '/shm@0x0c000000/reg 0x0c000000 0x80000' \
  72          -o '/shm@0x0c000000/key 0x12345678' ../psim-hello/hello
  73
  74    BUGS
  75
  76    None known.
  77
  78    */
  79
  80 typedef struct _hw_shm_device {
  81   unsigned_word physical_address;
  82   char *shm_address;
  83   unsigned sizeof_memory;
  84   key_t key;
  85   int id;
  86 } hw_shm_device;
  87
  88 static void
  89 hw_shm_init_data(device *me)
  90 {
  91   hw_shm_device *shm = (hw_shm_device*)device_data(me);
  92   reg_property_spec reg;
  93   int i;
  94
  95   /* Obtain the Key Value */
  96   if (device_find_property(me, "key") == NULL)
  97     error("shm_init_data() required key property is missing\n");
  98
  99   shm->key = (key_t) device_find_integer_property(me, "key");
 100   DTRACE(shm, ("shm key (0x%08x)\n", shm->key) );
 101
 102   /* Figure out where this memory is in address space and how long it is */
 103   if ( !device_find_reg_array_property(me, "reg", 0, &reg) )
 104     error("hw_shm_init_data() no address registered\n");
 105
 106   /* Determine the address and length being as paranoid as possible */
 107   shm->physical_address = 0xffffffff;
 108   shm->sizeof_memory = 0xffffffff;
 109
 110   for ( i=0 ; i<reg.address.nr_cells; i++ ) {
 111     if (reg.address.cells[0] == 0 && reg.size.cells[0] == 0)
 112       continue;
 113
 114     if ( shm->physical_address != 0xffffffff )
 115       device_error(me, "Only single celled address ranges supported\n");
 116
 117     shm->physical_address = reg.address.cells[i];
 118     DTRACE(shm, ("shm physical_address=0x%x\n", shm->physical_address));
 119
 120     shm->sizeof_memory = reg.size.cells[i];
 121     DTRACE(shm, ("shm length=0x%x\n", shm->sizeof_memory));
 122   }
 123
 124   if ( shm->physical_address == 0xffffffff )
 125     device_error(me, "Address not specified\n" );
 126
 127   if ( shm->sizeof_memory == 0xffffffff )
 128     device_error(me, "Length not specified\n" );
 129
 130   /* Now actually attach to or create the shared memory area */
 131   shm->id = shmget(shm->key, shm->sizeof_memory, IPC_CREAT | 0660);
 132   if (shm->id == -1)
 133     error("hw_shm_init_data() shmget failed\n");
 134
 135   shm->shm_address = shmat(shm->id, (char *)0, SHM_RND);
 136   if (shm->shm_address == (void *)-1)
 137     error("hw_shm_init_data() shmat failed\n");
 138 }
 139
 140 static void
 141 hw_shm_attach_address_callback(device *me,
 142                                 attach_type attach,
 143                                 int space,
 144                                 unsigned_word addr,
 145                                 unsigned nr_bytes,
 146                                 access_type access,
 147                                 device *client) /*callback/default*/
 148 {
 149   if (space != 0)
 150     error("shm_attach_address_callback() invalid address space\n");
 151
 152   if (nr_bytes == 0)
 153     error("shm_attach_address_callback() invalid size\n");
 154 }
 155
 156
 157 static unsigned
 158 hw_shm_io_read_buffer(device *me,
 159                          void *dest,
 160                          int space,
 161                          unsigned_word addr,
 162                          unsigned nr_bytes,
 163                          cpu *processor,
 164                          unsigned_word cia)
 165 {
 166   hw_shm_device *shm = (hw_shm_device*)device_data(me);
 167
 168   /* do we need to worry about out of range addresses? */
 169
 170   DTRACE(shm, ("read %p %x %x %x\n", \
 171      shm->shm_address, shm->physical_address, addr, nr_bytes) );
 172
 173   memcpy(dest, &shm->shm_address[addr - shm->physical_address], nr_bytes);
 174   return nr_bytes;
 175 }
 176
 177
 178 static unsigned
 179 hw_shm_io_write_buffer(device *me,
 180                           const void *source,
 181                           int space,
 182                           unsigned_word addr,
 183                           unsigned nr_bytes,
 184                           cpu *processor,
 185                           unsigned_word cia)
 186 {
 187   hw_shm_device *shm = (hw_shm_device*)device_data(me);
 188
 189   /* do we need to worry about out of range addresses? */
 190
 191   DTRACE(shm, ("write %p %x %x %x\n", \
 192      shm->shm_address, shm->physical_address, addr, nr_bytes) );
 193
 194   memcpy(&shm->shm_address[addr - shm->physical_address], source, nr_bytes);
 195   return nr_bytes;
 196 }
 197
 198 static device_callbacks const hw_shm_callbacks = {
 199   { generic_device_init_address, hw_shm_init_data },
 200   { hw_shm_attach_address_callback, }, /* address */
 201   { hw_shm_io_read_buffer,
 202     hw_shm_io_write_buffer }, /* IO */
 203   { NULL, }, /* DMA */
 204   { NULL, }, /* interrupt */
 205   { NULL, }, /* unit */
 206   NULL,
 207 };
 208
 209 static void *
 210 hw_shm_create(const char *name,
 211                  const device_unit *unit_address,
 212                  const char *args)
 213 {
 214   hw_shm_device *shm = ZALLOC(hw_shm_device);
 215   return shm;
 216 }
 217
 218
 219
 220 const device_descriptor hw_shm_device_descriptor[] = {
 221   { "shm", hw_shm_create, &hw_shm_callbacks },
 222   { NULL },
 223 };
 224
 225 #endif /* _HW_SHM_C_ */