sim/common/dv-glue.c

   1 /* The common simulator framework for GDB, the GNU Debugger.
   2
   3    Copyright 2002, 2007, 2008, 2009, 2010, 2011 Free Software Foundation, Inc.
   4
   5    Contributed by Andrew Cagney and Red Hat.
   6
   7    This file is part of GDB.
   8
   9    This program is free software; you can redistribute it and/or modify
  10    it under the terms of the GNU General Public License as published by
  11    the Free Software Foundation; either version 3 of the License, or
  12    (at your option) any later version.
  13
  14    This program is distributed in the hope that it will be useful,
  15    but WITHOUT ANY WARRANTY; without even the implied warranty of
  16    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  17    GNU General Public License for more details.
  18
  19    You should have received a copy of the GNU General Public License
  20    along with this program.  If not, see <http://www.gnu.org/licenses/>.  */
  21
  22
  23 #include "hw-main.h"
  24
  25 #ifdef HAVE_STRING_H
  26 #include <string.h>
  27 #else
  28 #ifdef HAVE_STRINGS_H
  29 #include <strings.h>
  30 #endif
  31 #endif
  32
  33 /* DEVICE
  34
  35
  36    glue - glue to interconnect and test hardware ports
  37
  38
  39    DESCRIPTION
  40
  41
  42    The glue device provides two functions.  Firstly, it provides a
  43    mechanism for inspecting and driving the port network.  Secondly,
  44    it provides a set of boolean primitives that can be used to apply
  45    combinatorial operations to the port network.
  46
  47    Glue devices have a variable number of big endian <<output>>
  48    registers.  Each register is target-word sized.  The registers can
  49    be read and written.
  50
  51    Writing to an output register results in an event being driven
  52    (level determined by the value written) on the devices
  53    corresponding output port.
  54
  55    Reading an <<output>> register returns either the last value
  56    written or the most recently computed value (for that register) as
  57    a result of an event ariving on that port (which ever was computed
  58    last).
  59
  60    At present the following sub device types are available:
  61
  62    <<glue>>: In addition to driving its output interrupt port with any
  63    value written to an interrupt input port is stored in the
  64    corresponding <<output>> register.  Such input interrupts, however,
  65    are not propogated to an output interrupt port.
  66
  67    <<glue-and>>: The bit-wise AND of the interrupt inputs is computed
  68    and then both stored in <<output>> register zero and propogated to
  69    output interrupt output port zero.
  70
  71
  72    PROPERTIES
  73
  74
  75    reg = <address> <size> (required)
  76
  77    Specify the address (within the parent bus) that this device is to
  78    live.  The address must be 2048 * sizeof (word) (8k in a 32bit
  79    simulation) aligned.
  80
  81
  82    interrupt-ranges = <int-number> <range> (optional)
  83
  84    If present, this specifies the number of valid interrupt inputs (up
  85    to the maximum of 2048).  By default, <<int-number>> is zero and
  86    range is determined by the <<reg>> size.
  87
  88
  89    PORTS
  90
  91
  92    int[0..] (input, output)
  93
  94    Both an input and an output port.
  95
  96
  97    EXAMPLES
  98
  99
 100    Enable tracing of the device:
 101
 102    | -t glue-device \
 103
 104
 105    Create source, bitwize-and, and sink glue devices.  Since the
 106    device at address <<0x10000>> is of size <<8>> it will have two
 107    output interrupt ports.
 108
 109    | -o '/iobus@0xf0000000/glue@0x10000/reg 0x10000 8' \
 110    | -o '/iobus@0xf0000000/glue-and@0x20000/reg 0x20000 4' \
 111    | -o '/iobus@0xf0000000/glue-and/interrupt-ranges 0 2' \
 112    | -o '/iobus@0xf0000000/glue@0x30000/reg 0x30000 4' \
 113
 114
 115    Wire the two source interrupts to the AND device:
 116
 117    | -o '/iobus@0xf0000000/glue@0x10000 > 0 0 /iobus/glue-and' \
 118    | -o '/iobus@0xf0000000/glue@0x10000 > 1 1 /iobus/glue-and' \
 119
 120
 121    Wire the AND device up to the sink so that the and's output is not
 122    left open.
 123
 124    | -o '/iobus@0xf0000000/glue-and > 0 0 /iobus/glue@0x30000' \
 125
 126
 127    With the above configuration.  The client program is able to
 128    compute a two bit AND.  For instance the <<C>> stub below prints 1
 129    AND 0.
 130
 131    |  unsigned *input = (void*)0xf0010000;
 132    |  unsigned *output = (void*)0xf0030000;
 133    |  unsigned ans;
 134    |  input[0] = htonl(1);
 135    |  input[1] = htonl(0);
 136    |  ans = ntohl(*output);
 137    |  write_string("AND is ");
 138    |  write_int(ans);
 139    |  write_line();
 140
 141
 142    BUGS
 143
 144
 145    A future implementation of this device may support multiple
 146    interrupt ranges.
 147
 148    Some of the devices listed may not yet be fully implemented.
 149
 150    Additional devices such as a D flip-flop (DFF), an inverter (INV)
 151    or a latch (LAT) may prove useful.
 152
 153    */
 154
 155
 156 enum
 157 {
 158   max_nr_ports = 2048,
 159 };
 160
 161 enum hw_glue_type
 162 {
 163   glue_undefined = 0,
 164   glue_io,
 165   glue_and,
 166   glue_nand,
 167   glue_or,
 168   glue_xor,
 169   glue_nor,
 170   glue_not,
 171 };
 172
 173 struct hw_glue
 174 {
 175   enum hw_glue_type type;
 176   int int_number;
 177   int *input;
 178   int nr_inputs;
 179   unsigned sizeof_input;
 180   /* our output registers */
 181   int space;
 182   unsigned_word address;
 183   unsigned sizeof_output;
 184   int *output;
 185   int nr_outputs;
 186 };
 187
 188
 189 static hw_io_read_buffer_method hw_glue_io_read_buffer;
 190 static hw_io_write_buffer_method hw_glue_io_write_buffer;
 191 static hw_port_event_method hw_glue_port_event;
 192 static const struct hw_port_descriptor hw_glue_ports[];
 193
 194 static void
 195 hw_glue_finish (struct hw *me)
 196 {
 197   struct hw_glue *glue = HW_ZALLOC (me, struct hw_glue);
 198   const char *name = hw_name (me);
 199
 200   /* establish our own methods */
 201   set_hw_data (me, glue);
 202   set_hw_io_read_buffer (me, hw_glue_io_read_buffer);
 203   set_hw_io_write_buffer (me, hw_glue_io_write_buffer);
 204   set_hw_ports (me, hw_glue_ports);
 205   set_hw_port_event (me, hw_glue_port_event);
 206
 207   /* attach to our parent bus */
 208   do_hw_attach_regs (me);
 209
 210   /* establish the output registers */
 211   if (hw_find_property (me, "reg"))
 212     {
 213       reg_property_spec unit;
 214       int reg_nr;
 215
 216       /* Find a relevant reg entry.  */
 217       reg_nr = 0;
 218       while (hw_find_reg_array_property (me, "reg", reg_nr, &unit)
 219              && !hw_unit_size_to_attach_size (hw_parent (me),
 220                                               &unit.size,
 221                                               &glue->sizeof_output,
 222                                               me))
 223         reg_nr++;
 224
 225       /* Check out the size ...  */
 226       if (glue->sizeof_output == 0)
 227         hw_abort (me, "at least one reg property size must be nonzero");
 228       if (glue->sizeof_output % sizeof (unsigned_word) != 0)
 229         hw_abort (me, "reg property size must be %ld aligned",
 230                   (long) sizeof (unsigned_word));
 231
 232       /* ... and the address.  */
 233       hw_unit_address_to_attach_address (hw_parent (me),
 234                                          &unit.address,
 235                                          &glue->space,
 236                                          &glue->address,
 237                                          me);
 238       if (glue->address % (sizeof (unsigned_word) * max_nr_ports) != 0)
 239         hw_abort (me, "reg property address must be %ld aligned",
 240                   (long) (sizeof (unsigned_word) * max_nr_ports));
 241
 242       glue->nr_outputs = glue->sizeof_output / sizeof (unsigned_word);
 243     }
 244   else
 245     {
 246       /* Allow bitwise glue devices to declare only ports.  */
 247       if (!strcmp (name, "glue"))
 248         hw_abort (me, "Missing \"reg\" property");
 249
 250       glue->nr_outputs = 1;
 251       glue->sizeof_output = sizeof (unsigned_word);
 252     }
 253   glue->output = hw_zalloc (me, glue->sizeof_output);
 254
 255   /* establish the input ports */
 256   {
 257     const struct hw_property *ranges;
 258
 259     ranges = hw_find_property (me, "interrupt-ranges");
 260     if (ranges == NULL)
 261       {
 262         glue->int_number = 0;
 263         glue->nr_inputs = glue->nr_outputs;
 264       }
 265     else if (ranges->sizeof_array != sizeof (unsigned_cell) * 2)
 266       {
 267         hw_abort (me, "invalid interrupt-ranges property (incorrect size)");
 268       }
 269     else
 270       {
 271         const unsigned_cell *int_range = ranges->array;
 272
 273         glue->int_number = BE2H_cell (int_range[0]);
 274         glue->nr_inputs = BE2H_cell (int_range[1]);
 275       }
 276     glue->sizeof_input = glue->nr_inputs * sizeof (unsigned);
 277     glue->input = hw_zalloc (me, glue->sizeof_input);
 278   }
 279
 280   /* determine our type */
 281   if (strcmp (name, "glue") == 0)
 282     glue->type = glue_io;
 283   else if (strcmp (name, "glue-and") == 0)
 284     glue->type = glue_and;
 285   else if (strcmp (name, "glue-or") == 0)
 286     glue->type = glue_or;
 287   else if (strcmp (name, "glue-xor") == 0)
 288     glue->type = glue_xor;
 289   else
 290     hw_abort (me, "unimplemented glue type");
 291
 292   HW_TRACE ((me, "int-number %d, nr_inputs %d, nr_outputs %d",
 293              glue->int_number, glue->nr_inputs, glue->nr_outputs));
 294 }
 295
 296 static unsigned
 297 hw_glue_io_read_buffer (struct hw *me,
 298                         void *dest,
 299                         int space,
 300                         unsigned_word addr,
 301                         unsigned nr_bytes)
 302 {
 303   struct hw_glue *glue = (struct hw_glue *) hw_data (me);
 304   int reg = ((addr - glue->address) / sizeof (unsigned_word)) % glue->nr_outputs;
 305
 306   if (nr_bytes != sizeof (unsigned_word)
 307       || (addr % sizeof (unsigned_word)) != 0)
 308     hw_abort (me, "missaligned read access (%d:0x%lx:%d) not supported",
 309               space, (unsigned long)addr, nr_bytes);
 310
 311   *(unsigned_word *)dest = H2BE_4 (glue->output[reg]);
 312
 313   HW_TRACE ((me, "read - port %d (0x%lx), level %d",
 314              reg, (unsigned long) addr, glue->output[reg]));
 315
 316   return nr_bytes;
 317 }
 318
 319
 320 static unsigned
 321 hw_glue_io_write_buffer (struct hw *me,
 322                          const void *source,
 323                          int space,
 324                          unsigned_word addr,
 325                          unsigned nr_bytes)
 326 {
 327   struct hw_glue *glue = (struct hw_glue *) hw_data (me);
 328   int reg = ((addr - glue->address) / sizeof (unsigned_word)) % max_nr_ports;
 329
 330   if (nr_bytes != sizeof (unsigned_word)
 331       || (addr % sizeof (unsigned_word)) != 0)
 332     hw_abort (me, "missaligned write access (%d:0x%lx:%d) not supported",
 333               space, (unsigned long) addr, nr_bytes);
 334
 335   glue->output[reg] = H2BE_4 (*(unsigned_word *)source);
 336
 337   HW_TRACE ((me, "write - port %d (0x%lx), level %d",
 338              reg, (unsigned long) addr, glue->output[reg]));
 339
 340   hw_port_event (me, reg, glue->output[reg]);
 341
 342   return nr_bytes;
 343 }
 344
 345 static void
 346 hw_glue_port_event (struct hw *me,
 347                     int my_port,
 348                     struct hw *source,
 349                     int source_port,
 350                     int level)
 351 {
 352   struct hw_glue *glue = (struct hw_glue *) hw_data (me);
 353   int i;
 354
 355   if (my_port < glue->int_number
 356       || my_port >= glue->int_number + glue->nr_inputs)
 357     hw_abort (me, "port %d outside of valid range", my_port);
 358
 359   glue->input[my_port - glue->int_number] = level;
 360   switch (glue->type)
 361     {
 362     case glue_io:
 363       {
 364         int port = my_port % glue->nr_outputs;
 365
 366         glue->output[port] = level;
 367
 368         HW_TRACE ((me, "input - port %d (0x%lx), level %d",
 369                    my_port,
 370                    (unsigned long) glue->address + port * sizeof (unsigned_word),
 371                    level));
 372         return;
 373       }
 374     case glue_and:
 375       {
 376         glue->output[0] = glue->input[0];
 377         for (i = 1; i < glue->nr_inputs; i++)
 378           glue->output[0] &= glue->input[i];
 379         break;
 380       }
 381     case glue_or:
 382       {
 383         glue->output[0] = glue->input[0];
 384         for (i = 1; i < glue->nr_inputs; i++)
 385           glue->output[0] |= glue->input[i];
 386         break;
 387       }
 388     case glue_xor:
 389       {
 390         glue->output[0] = glue->input[0];
 391         for (i = 1; i < glue->nr_inputs; i++)
 392           glue->output[0] ^= glue->input[i];
 393         break;
 394       }
 395     default:
 396       {
 397         hw_abort (me, "operator not implemented");
 398         return;
 399       }
 400     }
 401
 402   /* If we fell through, we want to generate a port event.  */
 403   HW_TRACE ((me, "port %d, level %d arrived - output %d",
 404              my_port, level, glue->output[0]));
 405
 406   hw_port_event (me, 0, glue->output[0]);
 407 }
 408
 409
 410 static const struct hw_port_descriptor hw_glue_ports[] =
 411 {
 412   { "int", 0, max_nr_ports, 0 },
 413   { NULL, 0, 0, 0 }
 414 };
 415
 416
 417 const struct hw_descriptor dv_glue_descriptor[] =
 418 {
 419   { "glue", hw_glue_finish, },
 420   { "glue-and", hw_glue_finish, },
 421   { "glue-nand", hw_glue_finish, },
 422   { "glue-or", hw_glue_finish, },
 423   { "glue-xor", hw_glue_finish, },
 424   { "glue-nor", hw_glue_finish, },
 425   { "glue-not", hw_glue_finish, },
 426   { NULL, NULL },
 427 };