hw_shm.c revision 1.2
1 /* This file is part of the program psim. 2 3 Copyright (C) 1997,2008, Joel Sherrill <joel (at) 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%08jx)\n", (intmax_t)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, ®) ) 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_ */ 226
Indexes created Tue Oct 27 00:25:24 UTC 2026