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/* This file is part of the program psim.
Copyright (C) 1997,2008, Joel Sherrill <joel@OARcorp.com>
This program is free software; you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation; either version 3 of the License, or
(at your option) any later version.
This program is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
GNU General Public License for more details.
You should have received a copy of the GNU General Public License
along with this program; if not, see <http://www.gnu.org/licenses/>.
*/
#ifndef _HW_SHM_C_
#define _HW_SHM_C_
#include "device_table.h"
#include <string.h>
#include <sys/ipc.h>
#include <sys/shm.h>
/* DEVICE
shm - map unix shared memory into psim address space
DESCRIPTION
This device implements an area of memory which is mapped into UNIX
shared memory.
PROPERTIES
reg = <address> <size> (required)
Determine where the memory lives in the parents address space.
The SHM area is assumed to be of the same length.
key = <integer> (required)
This is the key of the unix shared memory area.
EXAMPLES
Enable tracing of the shm:
| bash$ psim -t shm-device \
Configure a 512 kilobytes of UNIX shared memory with the key 0x12345678
mapped into psim address space at 0x0c000000.
| -o '/shm@0x0c000000/reg 0x0c000000 0x80000' \
| -o '/shm@0x0c000000/key 0x12345678' \
sim/ppc/run -o '/#address-cells 1' \
-o '/shm@0x0c000000/reg 0x0c000000 0x80000' \
-o '/shm@0x0c000000/key 0x12345678' ../psim-hello/hello
BUGS
None known.
*/
typedef struct _hw_shm_device {
unsigned_word physical_address;
char *shm_address;
unsigned sizeof_memory;
key_t key;
int id;
} hw_shm_device;
static void
hw_shm_init_data(device *me)
{
hw_shm_device *shm = (hw_shm_device*)device_data(me);
reg_property_spec reg;
int i;
/* Obtain the Key Value */
if (device_find_property(me, "key") == NULL)
error("shm_init_data() required key property is missing\n");
shm->key = (key_t) device_find_integer_property(me, "key");
DTRACE(shm, ("shm key (0x%08x)\n", shm->key) );
/* Figure out where this memory is in address space and how long it is */
if ( !device_find_reg_array_property(me, "reg", 0, &reg) )
error("hw_shm_init_data() no address registered\n");
/* Determine the address and length being as paranoid as possible */
shm->physical_address = 0xffffffff;
shm->sizeof_memory = 0xffffffff;
for ( i=0 ; i<reg.address.nr_cells; i++ ) {
if (reg.address.cells[0] == 0 && reg.size.cells[0] == 0)
continue;
if ( shm->physical_address != 0xffffffff )
device_error(me, "Only single celled address ranges supported\n");
shm->physical_address = reg.address.cells[i];
DTRACE(shm, ("shm physical_address=0x%x\n", shm->physical_address));
shm->sizeof_memory = reg.size.cells[i];
DTRACE(shm, ("shm length=0x%x\n", shm->sizeof_memory));
}
if ( shm->physical_address == 0xffffffff )
device_error(me, "Address not specified\n" );
if ( shm->sizeof_memory == 0xffffffff )
device_error(me, "Length not specified\n" );
/* Now actually attach to or create the shared memory area */
shm->id = shmget(shm->key, shm->sizeof_memory, IPC_CREAT | 0660);
if (shm->id == -1)
error("hw_shm_init_data() shmget failed\n");
shm->shm_address = shmat(shm->id, (char *)0, SHM_RND);
if (shm->shm_address == (void *)-1)
error("hw_shm_init_data() shmat failed\n");
}
static void
hw_shm_attach_address_callback(device *me,
attach_type attach,
int space,
unsigned_word addr,
unsigned nr_bytes,
access_type access,
device *client) /*callback/default*/
{
if (space != 0)
error("shm_attach_address_callback() invalid address space\n");
if (nr_bytes == 0)
error("shm_attach_address_callback() invalid size\n");
}
static unsigned
hw_shm_io_read_buffer(device *me,
void *dest,
int space,
unsigned_word addr,
unsigned nr_bytes,
cpu *processor,
unsigned_word cia)
{
hw_shm_device *shm = (hw_shm_device*)device_data(me);
/* do we need to worry about out of range addresses? */
DTRACE(shm, ("read %p %x %x %x\n", \
shm->shm_address, shm->physical_address, addr, nr_bytes) );
memcpy(dest, &shm->shm_address[addr - shm->physical_address], nr_bytes);
return nr_bytes;
}
static unsigned
hw_shm_io_write_buffer(device *me,
const void *source,
int space,
unsigned_word addr,
unsigned nr_bytes,
cpu *processor,
unsigned_word cia)
{
hw_shm_device *shm = (hw_shm_device*)device_data(me);
/* do we need to worry about out of range addresses? */
DTRACE(shm, ("write %p %x %x %x\n", \
shm->shm_address, shm->physical_address, addr, nr_bytes) );
memcpy(&shm->shm_address[addr - shm->physical_address], source, nr_bytes);
return nr_bytes;
}
static device_callbacks const hw_shm_callbacks = {
{ generic_device_init_address, hw_shm_init_data },
{ hw_shm_attach_address_callback, }, /* address */
{ hw_shm_io_read_buffer,
hw_shm_io_write_buffer }, /* IO */
{ NULL, }, /* DMA */
{ NULL, }, /* interrupt */
{ NULL, }, /* unit */
NULL,
};
static void *
hw_shm_create(const char *name,
const device_unit *unit_address,
const char *args)
{
hw_shm_device *shm = ZALLOC(hw_shm_device);
return shm;
}
const device_descriptor hw_shm_device_descriptor[] = {
{ "shm", hw_shm_create, &hw_shm_callbacks },
{ NULL },
};
#endif /* _HW_SHM_C_ */