aboutsummaryrefslogtreecommitdiff
path: root/sim/common/dv-glue.c
blob: 7c8e1f877af27d3c9f3da70ba62b00b619c2e12a (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
/* The common simulator framework for GDB, the GNU Debugger.

   Copyright 2002-2021 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 "hw-main.h"

#include <string.h>

/* DEVICE


   glue - glue to interconnect and test hardware ports


   DESCRIPTION


   The glue device provides two functions.  Firstly, it provides a
   mechanism for inspecting and driving the port network.  Secondly,
   it provides a set of boolean primitives that can be used to apply
   combinatorial operations to the port network.

   Glue devices have a variable number of big endian <<output>>
   registers.  Each register is target-word sized.  The registers can
   be read and written.

   Writing to an output register results in an event being driven
   (level determined by the value written) on the devices
   corresponding output port.

   Reading an <<output>> register returns either the last value
   written or the most recently computed value (for that register) as
   a result of an event ariving on that port (which ever was computed
   last).

   At present the following sub device types are available:

   <<glue>>: In addition to driving its output interrupt port with any
   value written to an interrupt input port is stored in the
   corresponding <<output>> register.  Such input interrupts, however,
   are not propogated to an output interrupt port.

   <<glue-and>>: The bit-wise AND of the interrupt inputs is computed
   and then both stored in <<output>> register zero and propogated to
   output interrupt output port zero.


   PROPERTIES


   reg = <address> <size> (required)

   Specify the address (within the parent bus) that this device is to
   live.  The address must be 2048 * sizeof (word) (8k in a 32bit
   simulation) aligned.


   interrupt-ranges = <int-number> <range> (optional)

   If present, this specifies the number of valid interrupt inputs (up
   to the maximum of 2048).  By default, <<int-number>> is zero and
   range is determined by the <<reg>> size.


   PORTS


   int[0..] (input, output)

   Both an input and an output port.


   EXAMPLES


   Enable tracing of the device:

   | -t glue-device \


   Create source, bitwize-and, and sink glue devices.  Since the
   device at address <<0x10000>> is of size <<8>> it will have two
   output interrupt ports.

   | -o '/iobus@0xf0000000/glue@0x10000/reg 0x10000 8' \
   | -o '/iobus@0xf0000000/glue-and@0x20000/reg 0x20000 4' \
   | -o '/iobus@0xf0000000/glue-and/interrupt-ranges 0 2' \
   | -o '/iobus@0xf0000000/glue@0x30000/reg 0x30000 4' \


   Wire the two source interrupts to the AND device:

   | -o '/iobus@0xf0000000/glue@0x10000 > 0 0 /iobus/glue-and' \
   | -o '/iobus@0xf0000000/glue@0x10000 > 1 1 /iobus/glue-and' \


   Wire the AND device up to the sink so that the and's output is not
   left open.

   | -o '/iobus@0xf0000000/glue-and > 0 0 /iobus/glue@0x30000' \


   With the above configuration.  The client program is able to
   compute a two bit AND.  For instance the <<C>> stub below prints 1
   AND 0.

   |  unsigned *input = (void*)0xf0010000;
   |  unsigned *output = (void*)0xf0030000;
   |  unsigned ans;
   |  input[0] = htonl(1);
   |  input[1] = htonl(0);
   |  ans = ntohl(*output);
   |  write_string("AND is ");
   |  write_int(ans);
   |  write_line();


   BUGS


   A future implementation of this device may support multiple
   interrupt ranges.

   Some of the devices listed may not yet be fully implemented.

   Additional devices such as a D flip-flop (DFF), an inverter (INV)
   or a latch (LAT) may prove useful.

   */


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 },
};