path: root/sim/common/dv-glue.c

/* The common simulator framework for GDB, the GNU Debugger.

   Copyright 2002-2022 Free Software Foundation, Inc.

   Contributed by Andrew Cagney and Red Hat.

   This file is part of GDB.

   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/>.  */

/* This must come before any other includes.  */
#include "defs.h"

#include <string.h>

#include "hw-main.h"

enum
{
  max_nr_ports = 2048,
};

enum hw_glue_type
{
  glue_undefined = 0,
  glue_io,
  glue_and,
  glue_nand,
  glue_or,
  glue_xor,
  glue_nor,
  glue_not,
};

struct hw_glue
{
  enum hw_glue_type type;
  int int_number;
  int *input;
  int nr_inputs;
  unsigned sizeof_input;
  /* our output registers */
  int space;
  unsigned_word address;
  unsigned sizeof_output;
  int *output;
  int nr_outputs;
};


static hw_io_read_buffer_method hw_glue_io_read_buffer;
static hw_io_write_buffer_method hw_glue_io_write_buffer;
static hw_port_event_method hw_glue_port_event;
static const struct hw_port_descriptor hw_glue_ports[];

static void
hw_glue_finish (struct hw *me)
{
  struct hw_glue *glue = HW_ZALLOC (me, struct hw_glue);
  const char *name = hw_name (me);

  /* establish our own methods */
  set_hw_data (me, glue);
  set_hw_io_read_buffer (me, hw_glue_io_read_buffer);
  set_hw_io_write_buffer (me, hw_glue_io_write_buffer);
  set_hw_ports (me, hw_glue_ports);
  set_hw_port_event (me, hw_glue_port_event);

  /* attach to our parent bus */
  do_hw_attach_regs (me);

  /* establish the output registers */
  if (hw_find_property (me, "reg"))
    {
      reg_property_spec unit;
      int reg_nr;

      /* Find a relevant reg entry.  */
      reg_nr = 0;
      while (hw_find_reg_array_property (me, "reg", reg_nr, &unit)
	     && !hw_unit_size_to_attach_size (hw_parent (me),
					      &unit.size,
					      &glue->sizeof_output,
					      me))
	reg_nr++;

      /* Check out the size ...  */
      if (glue->sizeof_output == 0)
	hw_abort (me, "at least one reg property size must be nonzero");
      if (glue->sizeof_output % sizeof (unsigned_word) != 0)
	hw_abort (me, "reg property size must be %ld aligned",
		  (long) sizeof (unsigned_word));

      /* ... and the address.  */
      hw_unit_address_to_attach_address (hw_parent (me),
					 &unit.address,
					 &glue->space,
					 &glue->address,
					 me);
      if (glue->address % (sizeof (unsigned_word) * max_nr_ports) != 0)
	hw_abort (me, "reg property address must be %ld aligned",
		  (long) (sizeof (unsigned_word) * max_nr_ports));

      glue->nr_outputs = glue->sizeof_output / sizeof (unsigned_word);
    }
  else
    {
      /* Allow bitwise glue devices to declare only ports.  */
      if (!strcmp (name, "glue"))
	hw_abort (me, "Missing \"reg\" property");

      glue->nr_outputs = 1;
      glue->sizeof_output = sizeof (unsigned_word);
    }
  glue->output = hw_zalloc (me, glue->sizeof_output);

  /* establish the input ports */
  {
    const struct hw_property *ranges;

    ranges = hw_find_property (me, "interrupt-ranges");
    if (ranges == NULL)
      {
	glue->int_number = 0;
	glue->nr_inputs = glue->nr_outputs;
      }
    else if (ranges->sizeof_array != sizeof (unsigned_cell) * 2)
      {
	hw_abort (me, "invalid interrupt-ranges property (incorrect size)");
      }
    else
      {
	const unsigned_cell *int_range = ranges->array;

	glue->int_number = BE2H_cell (int_range[0]);
	glue->nr_inputs = BE2H_cell (int_range[1]);
      }
    glue->sizeof_input = glue->nr_inputs * sizeof (unsigned);
    glue->input = hw_zalloc (me, glue->sizeof_input);
  }

  /* determine our type */
  if (strcmp (name, "glue") == 0)
    glue->type = glue_io;
  else if (strcmp (name, "glue-and") == 0)
    glue->type = glue_and;
  else if (strcmp (name, "glue-or") == 0)
    glue->type = glue_or;
  else if (strcmp (name, "glue-xor") == 0)
    glue->type = glue_xor;
  else
    hw_abort (me, "unimplemented glue type");

  HW_TRACE ((me, "int-number %d, nr_inputs %d, nr_outputs %d",
	     glue->int_number, glue->nr_inputs, glue->nr_outputs));
}

static unsigned
hw_glue_io_read_buffer (struct hw *me,
			void *dest,
			int space,
			unsigned_word addr,
			unsigned nr_bytes)
{
  struct hw_glue *glue = (struct hw_glue *) hw_data (me);
  int reg = ((addr - glue->address) / sizeof (unsigned_word)) % glue->nr_outputs;

  if (nr_bytes != sizeof (unsigned_word)
      || (addr % sizeof (unsigned_word)) != 0)
    hw_abort (me, "missaligned read access (%d:0x%lx:%d) not supported",
	      space, (unsigned long)addr, nr_bytes);

  *(unsigned_word *)dest = H2BE_4 (glue->output[reg]);

  HW_TRACE ((me, "read - port %d (0x%lx), level %d",
	     reg, (unsigned long) addr, glue->output[reg]));

  return nr_bytes;
}


static unsigned
hw_glue_io_write_buffer (struct hw *me,
			 const void *source,
			 int space,
			 unsigned_word addr,
			 unsigned nr_bytes)
{
  struct hw_glue *glue = (struct hw_glue *) hw_data (me);
  int reg = ((addr - glue->address) / sizeof (unsigned_word)) % max_nr_ports;

  if (nr_bytes != sizeof (unsigned_word)
      || (addr % sizeof (unsigned_word)) != 0)
    hw_abort (me, "missaligned write access (%d:0x%lx:%d) not supported",
	      space, (unsigned long) addr, nr_bytes);

  glue->output[reg] = H2BE_4 (*(unsigned_word *)source);

  HW_TRACE ((me, "write - port %d (0x%lx), level %d",
	     reg, (unsigned long) addr, glue->output[reg]));

  hw_port_event (me, reg, glue->output[reg]);

  return nr_bytes;
}

static void
hw_glue_port_event (struct hw *me,
		    int my_port,
		    struct hw *source,
		    int source_port,
		    int level)
{
  struct hw_glue *glue = (struct hw_glue *) hw_data (me);
  int i;

  if (my_port < glue->int_number
      || my_port >= glue->int_number + glue->nr_inputs)
    hw_abort (me, "port %d outside of valid range", my_port);

  glue->input[my_port - glue->int_number] = level;
  switch (glue->type)
    {
    case glue_io:
      {
	int port = my_port % glue->nr_outputs;

	glue->output[port] = level;

	HW_TRACE ((me, "input - port %d (0x%lx), level %d",
		   my_port,
		   (unsigned long) glue->address + port * sizeof (unsigned_word),
		   level));
	return;
      }
    case glue_and:
      {
	glue->output[0] = glue->input[0];
	for (i = 1; i < glue->nr_inputs; i++)
	  glue->output[0] &= glue->input[i];
	break;
      }
    case glue_or:
      {
	glue->output[0] = glue->input[0];
	for (i = 1; i < glue->nr_inputs; i++)
	  glue->output[0] |= glue->input[i];
	break;
      }
    case glue_xor:
      {
	glue->output[0] = glue->input[0];
	for (i = 1; i < glue->nr_inputs; i++)
	  glue->output[0] ^= glue->input[i];
	break;
      }
    default:
      {
	hw_abort (me, "operator not implemented");
	return;
      }
    }

  /* If we fell through, we want to generate a port event.  */
  HW_TRACE ((me, "port %d, level %d arrived - output %d",
	     my_port, level, glue->output[0]));

  hw_port_event (me, 0, glue->output[0]);
}


static const struct hw_port_descriptor hw_glue_ports[] =
{
  { "int", 0, max_nr_ports, 0 },
  { NULL, 0, 0, 0 }
};


const struct hw_descriptor dv_glue_descriptor[] =
{
  { "glue", hw_glue_finish, },
  { "glue-and", hw_glue_finish, },
  { "glue-nand", hw_glue_finish, },
  { "glue-or", hw_glue_finish, },
  { "glue-xor", hw_glue_finish, },
  { "glue-nor", hw_glue_finish, },
  { "glue-not", hw_glue_finish, },
  { NULL, NULL },
};