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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 2 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, write to the Free Software

    Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.

    */

#ifndef _HW_SHM_C_

#define _HW_SHM_C_

#include "device_table.h"

#ifdef HAVE_STRING_H

#include <string.h>

#else

#ifdef HAVE_STRINGS_H

#include <strings.h>

#endif

#endif

#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);

  const device_unit *d;

  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*/

{

  hw_shm_device *shm = (hw_shm_device*)device_data(me);

  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_ */