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2 pj 1
/*
2
 * Project: S.Ha.R.K.
3
 *
4
 * Coordinators:
5
 *   Giorgio Buttazzo    <giorgio@sssup.it>
6
 *   Paolo Gai           <pj@gandalf.sssup.it>
7
 *
8
 * Authors     :
9
 *   Paolo Gai           <pj@gandalf.sssup.it>
10
 *   Massimiliano Giorgi <massy@gandalf.sssup.it>
11
 *   Luca Abeni          <luca@gandalf.sssup.it>
12
 *   (see the web pages for full authors list)
13
 *
14
 * ReTiS Lab (Scuola Superiore S.Anna - Pisa - Italy)
15
 *
16
 * http://www.sssup.it
17
 * http://retis.sssup.it
18
 * http://shark.sssup.it
19
 */
20
 
21
/**
22
 ------------
38 pj 23
 CVS :        $Id: rm.c,v 1.4 2003-01-07 17:07:50 pj Exp $
2 pj 24
 
25
 File:        $File$
38 pj 26
 Revision:    $Revision: 1.4 $
27
 Last update: $Date: 2003-01-07 17:07:50 $
2 pj 28
 ------------
29
 
30
 This file contains the scheduling module RM (Rate Monotonic)
31
 
32
 Read rm.h for further details.
33
 
34
 This file is equal to EDF.c except for:
35
 
36
 . EDF changed to RM :-)
37
 . q_timespec_insert changed to q_insert
38
 . proc_table[p].priority is also modified when we modify lev->period[p]
39
 
40
 
41
**/
42
 
43
/*
38 pj 44
 * Copyright (C) 2000,2002 Paolo Gai
2 pj 45
 *
46
 * This program is free software; you can redistribute it and/or modify
47
 * it under the terms of the GNU General Public License as published by
48
 * the Free Software Foundation; either version 2 of the License, or
49
 * (at your option) any later version.
50
 *
51
 * This program is distributed in the hope that it will be useful,
52
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
53
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
54
 * GNU General Public License for more details.
55
 *
56
 * You should have received a copy of the GNU General Public License
57
 * along with this program; if not, write to the Free Software
58
 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
59
 *
60
 */
61
 
62
 
63
#include <modules/rm.h>
64
#include <ll/stdio.h>
65
#include <ll/string.h>
66
#include <kernel/model.h>
67
#include <kernel/descr.h>
68
#include <kernel/var.h>
69
#include <kernel/func.h>
70
#include <kernel/trace.h>
71
 
72
/*+ Status used in the level +*/
73
#define RM_READY         MODULE_STATUS_BASE    /*+ - Ready status        +*/
74
#define RM_WCET_VIOLATED MODULE_STATUS_BASE+2  /*+ when wcet is finished +*/
75
#define RM_WAIT          MODULE_STATUS_BASE+3  /*+ to wait the deadline  +*/
76
#define RM_IDLE          MODULE_STATUS_BASE+4  /*+ to wait the deadline  +*/
77
#define RM_ZOMBIE        MODULE_STATUS_BASE+5  /*+ to wait the free time +*/
78
 
79
/*+ flags +*/
80
#define RM_FLAG_SPORADIC    1
81
#define RM_FLAG_NORAISEEXC  2
82
 
83
/*+ the level redefinition for the Rate Monotonic +*/
84
typedef struct {
85
  level_des l;     /*+ the standard level descriptor          +*/
86
 
87
  TIME period[MAX_PROC]; /*+ The task periods; the deadlines are
88
                       stored in the priority field           +*/
89
  int deadline_timer[MAX_PROC];
90
                   /*+ The task deadline timers               +*/
91
 
92
  int flag[MAX_PROC];
93
                   /*+ used to manage the JOB_TASK_MODEL and the
94
                       periodicity                            +*/
95
 
29 pj 96
  IQUEUE ready;     /*+ the ready queue                        +*/
2 pj 97
 
98
  int flags;       /*+ the init flags...                      +*/
99
 
100
  bandwidth_t U;   /*+ the used bandwidth                     +*/
101
 
102
} RM_level_des;
103
 
104
 
105
static void RM_timer_deadline(void *par)
106
{
107
  PID p = (PID) par;
108
  RM_level_des *lev;
29 pj 109
  struct timespec *temp;
2 pj 110
 
111
  lev = (RM_level_des *)level_table[proc_table[p].task_level];
112
 
113
  switch (proc_table[p].status) {
114
    case RM_ZOMBIE:
115
      /* we finally put the task in the ready queue */
116
      proc_table[p].status = FREE;
29 pj 117
      iq_insertfirst(p,&freedesc);
2 pj 118
      /* and free the allocated bandwidth */
119
      lev->U -= (MAX_BANDWIDTH/lev->period[p]) * proc_table[p].wcet;
120
      break;
121
 
122
    case RM_IDLE:
123
      /* tracer stuff */
124
      trc_logevent(TRC_INTACTIVATION,&p);
125
      /* similar to RM_task_activate */
29 pj 126
      temp = iq_query_timespec(p, &lev->ready);
127
      ADDUSEC2TIMESPEC(lev->period[p], temp);
2 pj 128
      proc_table[p].status = RM_READY;
29 pj 129
      iq_priority_insert(p,&lev->ready);
130
      lev->deadline_timer[p] = kern_event_post(temp,
2 pj 131
                                               RM_timer_deadline,
132
                                               (void *)p);
133
      //printk("(d%d idle priority set to %d)",p,proc_table[p].priority );
134
      event_need_reschedule();
135
      printk("el%d|",p);
136
      break;
137
 
138
    case RM_WAIT:
139
      /* Without this, the task cannot be reactivated!!! */
140
      proc_table[p].status = SLEEP;
141
      break;
142
 
143
    default:
144
      /* else, a deadline miss occurred!!! */
145
      kern_printf("timer_deadline:AAARRRGGGHHH!!!");
146
      kern_raise(XDEADLINE_MISS,p);
147
  }
148
}
149
 
150
static void RM_timer_guest_deadline(void *par)
151
{
152
  PID p = (PID) par;
153
 
154
  kern_printf("AAARRRGGGHHH!!!");
155
  kern_raise(XDEADLINE_MISS,p);
156
}
157
 
158
/* The scheduler only gets the first task in the queue */
38 pj 159
static PID RM_public_scheduler(LEVEL l)
2 pj 160
{
161
  RM_level_des *lev = (RM_level_des *)(level_table[l]);
162
 
29 pj 163
  return iq_query_first(&lev->ready);
2 pj 164
}
165
 
166
/* The on-line guarantee is enabled only if the appropriate flag is set... */
38 pj 167
static int RM_public_guarantee(LEVEL l, bandwidth_t *freebandwidth)
2 pj 168
{
169
  RM_level_des *lev = (RM_level_des *)(level_table[l]);
170
 
171
  if (lev->flags & RM_FAILED_GUARANTEE) {
172
    *freebandwidth = 0;
173
    return 0;
174
  }
175
  else
176
    if (*freebandwidth >= lev->U) {
177
      *freebandwidth -= lev->U;
178
      return 1;
179
    }
180
    else
181
      return 0;
182
 
183
}
184
 
38 pj 185
static int RM_public_create(LEVEL l, PID p, TASK_MODEL *m)
2 pj 186
{
187
  RM_level_des *lev = (RM_level_des *)(level_table[l]);
188
 
38 pj 189
  HARD_TASK_MODEL *h;
2 pj 190
 
38 pj 191
  if (m->pclass != HARD_PCLASS) return -1;
192
  if (m->level != 0 && m->level != l) return -1;
193
  h = (HARD_TASK_MODEL *)m;
194
  if (!h->wcet || !h->mit) return -1;
195
  /* now we know that m is a valid model */
2 pj 196
 
29 pj 197
  *iq_query_priority(p, &lev->ready) = lev->period[p] = h->mit;
2 pj 198
 
199
  if (h->periodicity == APERIODIC)
200
    lev->flag[p] = RM_FLAG_SPORADIC;
201
  else
202
    lev->flag[p] = 0;
203
  lev->deadline_timer[p] = -1;
204
 
205
  /* Enable wcet check */
206
  if (lev->flags & RM_ENABLE_WCET_CHECK) {
207
    proc_table[p].avail_time = h->wcet;
208
    proc_table[p].wcet       = h->wcet;
209
    proc_table[p].control |= CONTROL_CAP;
210
  }
211
 
212
  /* update the bandwidth... */
213
  if (lev->flags & RM_ENABLE_GUARANTEE) {
214
    bandwidth_t b;
215
    b = (MAX_BANDWIDTH / h->mit) * h->wcet;
216
 
217
    /* really update lev->U, checking an overflow... */
218
    if (MAX_BANDWIDTH - lev->U > b)
219
      lev->U += b;
220
    else
221
      /* The task can NOT be guaranteed (U>MAX_BANDWIDTH)...
222
         in this case, we don't raise an exception... in fact, after the
223
         RM_task_create the task_create will call level_guarantee that return
224
         -1... return -1 in RM_task_create isn't correct, because:
225
           . generally, the guarantee must be done when also the resources
226
             are registered
227
           . returning -1 will cause the task_create to return with an errno
228
             ETASK_CREATE instead of ENO_GUARANTEE!!!
229
 
230
         Why I use the flag??? because if the lev->U overflows, if i.e. I set
231
         it to MAX_BANDWIDTH, I lose the correct allocated bandwidth...
232
      */
233
      lev->flags |= RM_FAILED_GUARANTEE;
234
  }
235
 
236
  return 0; /* OK, also if the task cannot be guaranteed... */
237
}
238
 
38 pj 239
static void RM_public_detach(LEVEL l, PID p)
2 pj 240
{
241
  /* the RM level doesn't introduce any dinamic allocated new field.
242
     we have only to reset the NO_GUARANTEE FIELD and decrement the allocated
243
     bandwidth */
244
 
245
  RM_level_des *lev = (RM_level_des *)(level_table[l]);
246
 
247
  if (lev->flags & RM_FAILED_GUARANTEE)
248
    lev->flags &= ~RM_FAILED_GUARANTEE;
249
  else
250
    lev->U -= (MAX_BANDWIDTH / lev->period[p]) * proc_table[p].wcet;
251
}
252
 
38 pj 253
static void RM_public_dispatch(LEVEL l, PID p, int nostop)
2 pj 254
{
255
  RM_level_des *lev = (RM_level_des *)(level_table[l]);
256
 
257
//  kern_printf("(disp %d)",p);
258
 
259
  /* the task state is set EXE by the scheduler()
260
     we extract the task from the ready queue
261
     NB: we can't assume that p is the first task in the queue!!! */
29 pj 262
  iq_extract(p, &lev->ready);
2 pj 263
}
264
 
38 pj 265
static void RM_public_epilogue(LEVEL l, PID p)
2 pj 266
{
267
  RM_level_des *lev = (RM_level_des *)(level_table[l]);
268
 
269
//  kern_printf("(epil %d)",p);
270
 
271
  /* check if the wcet is finished... */
272
  if ((lev->flags & RM_ENABLE_WCET_CHECK) && proc_table[p].avail_time <= 0) {
273
    /* if it is, raise a XWCET_VIOLATION exception */
274
    kern_raise(XWCET_VIOLATION,p);
275
    proc_table[p].status = RM_WCET_VIOLATED;
276
  }
277
  else {
278
    /* the task has been preempted. it returns into the ready queue... */
29 pj 279
    iq_priority_insert(p,&lev->ready);
2 pj 280
    proc_table[p].status = RM_READY;
281
  }
282
}
283
 
38 pj 284
static void RM_public_activate(LEVEL l, PID p)
2 pj 285
{
286
  RM_level_des *lev = (RM_level_des *)(level_table[l]);
29 pj 287
  struct timespec *temp;
2 pj 288
 
289
  if (proc_table[p].status == RM_WAIT) {
290
    kern_raise(XACTIVATION,p);
291
    return;
292
  }
293
 
294
  /* Test if we are trying to activate a non sleeping task    */
295
  /* Ignore this; the task is already active                  */
296
  if (proc_table[p].status != SLEEP &&
297
      proc_table[p].status != RM_WCET_VIOLATED)
298
    return;
299
 
300
 
301
  /* see also RM_timer_deadline */
29 pj 302
  temp = iq_query_timespec(p, &lev->ready);
38 pj 303
  kern_gettime(temp);
29 pj 304
  ADDUSEC2TIMESPEC(lev->period[p], temp);
2 pj 305
 
306
  /* Insert task in the correct position */
307
  proc_table[p].status = RM_READY;
29 pj 308
  iq_priority_insert(p,&lev->ready);
2 pj 309
 
310
  /* Set the deadline timer */
29 pj 311
  lev->deadline_timer[p] = kern_event_post(temp,
2 pj 312
                                           RM_timer_deadline,
313
                                           (void *)p);
314
}
315
 
38 pj 316
static void RM_public_unblock(LEVEL l, PID p)
2 pj 317
{
318
  RM_level_des *lev = (RM_level_des *)(level_table[l]);
319
 
38 pj 320
  /* Similar to RM_task_activate,
321
     but we don't check in what state the task is */
2 pj 322
 
323
  /* Insert task in the correct position */
324
  proc_table[p].status = RM_READY;
29 pj 325
  iq_priority_insert(p,&lev->ready);
2 pj 326
}
327
 
38 pj 328
static void RM_public_block(LEVEL l, PID p)
2 pj 329
{
330
  /* Extract the running task from the level
331
     . we have already extract it from the ready queue at the dispatch time.
332
     . the capacity event have to be removed by the generic kernel
333
     . the wcet don't need modification...
334
     . the state of the task is set by the calling function
335
     . the deadline must remain...
336
 
337
     So, we do nothing!!!
338
  */
339
}
340
 
38 pj 341
static int RM_public_message(LEVEL l, PID p, void *m)
2 pj 342
{
343
  RM_level_des *lev = (RM_level_des *)(level_table[l]);
344
 
345
  /* the task has terminated his job before it consume the wcet. All OK! */
346
  if (lev->flag[p] & RM_FLAG_SPORADIC)
347
    proc_table[p].status = RM_WAIT;
348
  else /* pclass = sporadic_pclass */
349
    proc_table[p].status = RM_IDLE;
350
 
351
  /* we reset the capacity counters... */
352
  if (lev->flags & RM_ENABLE_WCET_CHECK)
353
    proc_table[p].avail_time = proc_table[p].wcet;
354
 
38 pj 355
  jet_update_endcycle(); /* Update the Jet data... */
356
  trc_logevent(TRC_ENDCYCLE,&exec_shadow); /* tracer stuff */
357
 
2 pj 358
  /* when the deadline timer fire, it recognize the situation and set
38 pj 359
     correctly all the stuffs (like reactivation, sleep, etc... ) */
360
 
361
  return 0;
2 pj 362
}
363
 
38 pj 364
static void RM_public_end(LEVEL l, PID p)
2 pj 365
{
366
  proc_table[p].status = RM_ZOMBIE;
367
 
368
  /* When the deadline timer fire, it put the task descriptor in
369
     the free queue, and free the allocated bandwidth... */
370
}
371
 
38 pj 372
static void RM_private_insert(LEVEL l, PID p, TASK_MODEL *m)
2 pj 373
{
374
  RM_level_des *lev = (RM_level_des *)(level_table[l]);
38 pj 375
  JOB_TASK_MODEL *job;
2 pj 376
 
38 pj 377
  if (m->pclass != JOB_PCLASS || (m->level != 0 && m->level != l) ) {
378
    kern_raise(XINVALID_TASK, p);
379
    return;
380
  }
2 pj 381
 
38 pj 382
  job = (JOB_TASK_MODEL *)m;
2 pj 383
 
29 pj 384
  *iq_query_timespec(p,&lev->ready) = job->deadline;
38 pj 385
  *iq_query_priority(p, &lev->ready) = lev->period[p] = job->period;
2 pj 386
 
387
  lev->deadline_timer[p] = -1;
388
 
38 pj 389
  /* Insert task in the correct position */
390
  iq_priority_insert(p,&lev->ready);
391
  proc_table[p].status = RM_READY;
392
 
2 pj 393
  if (job->noraiseexc)
394
    lev->flag[p] = RM_FLAG_NORAISEEXC;
38 pj 395
  else {
2 pj 396
    lev->flag[p] = 0;
38 pj 397
    lev->deadline_timer[p] = kern_event_post(iq_query_timespec(p, &lev->ready),
398
                                             RM_timer_guest_deadline,
399
                                             (void *)p);
400
  }
2 pj 401
}
402
 
38 pj 403
static void RM_private_dispatch(LEVEL l, PID p, int nostop)
2 pj 404
{
405
  RM_level_des *lev = (RM_level_des *)(level_table[l]);
406
 
407
  /* the task state is set to EXE by the scheduler()
408
     we extract the task from the ready queue
409
     NB: we can't assume that p is the first task in the queue!!! */
29 pj 410
  iq_extract(p, &lev->ready);
2 pj 411
}
412
 
38 pj 413
static void RM_private_epilogue(LEVEL l, PID p)
2 pj 414
{
415
  RM_level_des *lev = (RM_level_des *)(level_table[l]);
416
 
417
  /* the task has been preempted. it returns into the ready queue... */
29 pj 418
  iq_priority_insert(p,&lev->ready);
2 pj 419
  proc_table[p].status = RM_READY;
420
}
421
 
38 pj 422
static void RM_private_extract(LEVEL l, PID p)
2 pj 423
{
424
  RM_level_des *lev = (RM_level_des *)(level_table[l]);
425
 
426
  //kern_printf("RM_guest_end: dline timer %d\n",lev->deadline_timer[p]);
427
  if (proc_table[p].status == RM_READY)
428
  {
29 pj 429
    iq_extract(p, &lev->ready);
2 pj 430
    //kern_printf("(g_end rdy extr)");
431
  }
432
 
433
  /* we remove the deadline timer, because the slice is finished */
434
  if (lev->deadline_timer[p] != NIL) {
435
//    kern_printf("RM_guest_end: dline timer %d\n",lev->deadline_timer[p]);
38 pj 436
    kern_event_delete(lev->deadline_timer[p]);
2 pj 437
    lev->deadline_timer[p] = NIL;
438
  }
439
 
440
}
441
 
442
/* Registration functions */
443
 
444
/*+ Registration function:
445
    int flags                 the init flags ... see rm.h +*/
38 pj 446
LEVEL RM_register_level(int flags)
2 pj 447
{
448
  LEVEL l;            /* the level that we register */
449
  RM_level_des *lev;  /* for readableness only */
450
  PID i;              /* a counter */
451
 
452
  printk("RM_register_level\n");
453
 
454
  /* request an entry in the level_table */
38 pj 455
  l = level_alloc_descriptor(sizeof(RM_level_des));
2 pj 456
 
38 pj 457
  lev = (RM_level_des *)level_table[l];
2 pj 458
 
459
  printk("    lev=%d\n",(int)lev);
460
 
461
  /* fill the standard descriptor */
38 pj 462
  lev->l.private_insert   = RM_private_insert;
463
  lev->l.private_extract  = RM_private_extract;
464
  lev->l.private_dispatch = RM_private_dispatch;
465
  lev->l.private_epilogue = RM_private_epilogue;
2 pj 466
 
38 pj 467
  lev->l.public_scheduler = RM_public_scheduler;
2 pj 468
  if (flags & RM_ENABLE_GUARANTEE)
38 pj 469
    lev->l.public_guarantee = RM_public_guarantee;
2 pj 470
  else
38 pj 471
    lev->l.public_guarantee = NULL;
2 pj 472
 
38 pj 473
  lev->l.public_create    = RM_public_create;
474
  lev->l.public_detach    = RM_public_detach;
475
  lev->l.public_end       = RM_public_end;
476
  lev->l.public_dispatch  = RM_public_dispatch;
477
  lev->l.public_epilogue  = RM_public_epilogue;
478
  lev->l.public_activate  = RM_public_activate;
479
  lev->l.public_unblock   = RM_public_unblock;
480
  lev->l.public_block     = RM_public_block;
481
  lev->l.public_message   = RM_public_message;
2 pj 482
 
483
  /* fill the RM descriptor part */
484
  for(i=0; i<MAX_PROC; i++) {
485
    lev->period[i]         = 0;
486
    lev->deadline_timer[i] = -1;
487
    lev->flag[i]          = 0;
488
  }
489
 
29 pj 490
  iq_init(&lev->ready, &freedesc, 0);
2 pj 491
  lev->flags = flags & 0x07;
492
  lev->U     = 0;
38 pj 493
 
494
  return l;
2 pj 495
}
496
 
497
bandwidth_t RM_usedbandwidth(LEVEL l)
498
{
499
  RM_level_des *lev = (RM_level_des *)(level_table[l]);
38 pj 500
 
501
  return lev->U;
2 pj 502
}
503