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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: tbs.c,v 1.4 2003-01-07 17:07:51 pj Exp $
2 pj 24
 
25
 File:        $File$
38 pj 26
 Revision:    $Revision: 1.4 $
27
 Last update: $Date: 2003-01-07 17:07:51 $
2 pj 28
 ------------
29
 
30
 This file contains the aperiodic server TBS (Total Bandwidth Server)
31
 
32
 Read tbs.h for further details.
33
 
34
**/
35
 
36
/*
37
 * Copyright (C) 2000 Paolo Gai
38
 *
39
 * This program is free software; you can redistribute it and/or modify
40
 * it under the terms of the GNU General Public License as published by
41
 * the Free Software Foundation; either version 2 of the License, or
42
 * (at your option) any later version.
43
 *
44
 * This program is distributed in the hope that it will be useful,
45
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
46
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
47
 * GNU General Public License for more details.
48
 *
49
 * You should have received a copy of the GNU General Public License
50
 * along with this program; if not, write to the Free Software
51
 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
52
 *
53
 */
54
 
55
 
56
#include <modules/tbs.h>
57
#include <ll/stdio.h>
58
#include <ll/string.h>
59
#include <kernel/model.h>
60
#include <kernel/descr.h>
61
#include <kernel/var.h>
62
#include <kernel/func.h>
38 pj 63
#include <kernel/trace.h>
2 pj 64
 
65
/*+ 4 debug purposes +*/
66
#undef TBS_TEST
67
 
68
/*+ Status used in the level +*/
69
#define TBS_WCET_VIOLATED APER_STATUS_BASE+2  /*+ when wcet is finished +*/
70
#define TBS_WAIT          APER_STATUS_BASE    /*+ waiting the service   +*/
71
 
72
/*+ task flags +*/
73
#define TBS_SAVE_ARRIVALS 1
74
 
75
/*+ the level redefinition for the Total Bandwidth Server level +*/
76
typedef struct {
77
  level_des l;     /*+ the standard level descriptor          +*/
78
 
79
  /* The wcet are stored in the task descriptor's priority
80
     field.                     */
81
 
82
  int nact[MAX_PROC];    /*+ used to record activations +*/
83
  BYTE flag[MAX_PROC];
84
 
85
  struct timespec lastdline; /*+ the last deadline assigned to
86
                                 a TBS task                   +*/
87
 
29 pj 88
  IQUEUE wait;      /*+ the wait queue of the TBS              +*/
2 pj 89
  PID activated;   /*+ the task inserted in another queue     +*/
90
 
91
  int flags;       /*+ the init flags...                      +*/
92
 
93
  bandwidth_t U;   /*+ the used bandwidth by the server       +*/
94
  int band_num;
95
  int band_den;
96
 
97
  LEVEL scheduling_level;
98
 
99
} TBS_level_des;
100
 
101
#ifdef TESTG
102
#include "drivers/glib.h"
103
#endif
104
 
105
/* This static function activates the task pointed by lev->activated) */
106
static __inline__ void TBS_activation(TBS_level_des *lev)
107
{
108
    PID p;             /* for readableness    */
109
    JOB_TASK_MODEL j;  /* the guest model     */
110
    TIME drel;         /* the relative deadline of the task */
111
    LEVEL m;           /* the master level... only for readableness */
112
 
113
#ifdef TESTG
114
    TIME x;
115
    extern TIME starttime;
116
#endif
117
 
118
    p = lev->activated;
119
    /* we compute a suitable deadline for the task */
120
    drel = (proc_table[p].wcet * lev->band_den) / lev->band_num;
121
 
122
    ADDUSEC2TIMESPEC(drel, &lev->lastdline);
123
 
124
#ifdef TESTG
125
    if (starttime) {
126
    x = ((lev->lastdline.tv_sec*1000000+lev->lastdline.tv_nsec/1000)/5000 - starttime) + 20;
127
    if (x<640)
128
      grx_plot(x, 15, 7);
129
    }
130
#endif
131
 
132
    /* and we insert the task in another level */
133
    m = lev->scheduling_level;
134
    job_task_default_model(j,lev->lastdline);
38 pj 135
    level_table[m]->private_insert(m,p,(TASK_MODEL *)&j);
2 pj 136
 
137
    #ifdef TBS_TEST
138
    kern_printf("TBS_activation: lastdline %ds %dns\n",lev->lastdline.tv_sec,lev->lastdline.tv_nsec);
139
    #endif
140
}
141
 
142
/* This static function reclaims the unused time of the task p */
143
static __inline__ void TBS_bandwidth_reclaiming(TBS_level_des *lev, PID p)
144
{
145
    TIME reclaimed;
146
    struct timespec r, sos;
147
 
148
//    kern_printf("%d ", proc_table[p].avail_time);
149
    reclaimed = (proc_table[p].avail_time * lev->band_den) / lev->band_num;
150
 
151
    r.tv_nsec = (reclaimed % 1000000) * 1000;
152
    r.tv_sec  = reclaimed / 1000000;
153
 
154
    SUBTIMESPEC(&lev->lastdline, &r, &sos);
155
    TIMESPEC_ASSIGN(&lev->lastdline, &sos);
156
 
157
    #ifdef TBS_TEST
158
    kern_printf("TBS_bandwidth_reclaiming: lastdline %ds %dns, reclaimed %d, avail %d\n",
159
              lev->lastdline.tv_sec, lev->lastdline.tv_nsec, reclaimed, proc_table[p].avail_time);
160
    #endif
161
}
162
 
163
/* The on-line guarantee is enabled only if the appropriate flag is set... */
38 pj 164
static int TBS_public_guarantee(LEVEL l, bandwidth_t *freebandwidth)
2 pj 165
{
166
  TBS_level_des *lev = (TBS_level_des *)(level_table[l]);
167
 
168
  if (*freebandwidth >= lev->U) {
169
    *freebandwidth -= lev->U;
170
    return 1;
171
  }
172
  else
173
    return 0;
174
}
175
 
38 pj 176
static int TBS_public_create(LEVEL l, PID p, TASK_MODEL *m)
2 pj 177
{
178
  TBS_level_des *lev = (TBS_level_des *)(level_table[l]);
179
 
180
  /* if the TBS_task_create is called, then the pclass must be a
181
     valid pclass. */
38 pj 182
  SOFT_TASK_MODEL *s;
2 pj 183
 
38 pj 184
  if (m->pclass != SOFT_PCLASS) return -1;
185
  if (m->level != 0 && m->level != l) return -1;
186
  s = (SOFT_TASK_MODEL *)m;
187
  if (!(s->wcet && s->periodicity == APERIODIC)) return -1;
188
 
2 pj 189
  proc_table[p].wcet       = s->wcet;
190
 
191
  /* Enable wcet check */
192
  if (lev->flags & TBS_ENABLE_WCET_CHECK) {
193
    proc_table[p].avail_time = s->wcet;
194
    proc_table[p].control   |= CONTROL_CAP;
195
  }
196
 
197
  lev->nact[p] = 0;
198
  if (s->arrivals == SAVE_ARRIVALS)
199
    lev->flag[p] = TBS_SAVE_ARRIVALS;
200
 
201
  return 0; /* OK, also if the task cannot be guaranteed... */
202
}
203
 
38 pj 204
static void TBS_public_dispatch(LEVEL l, PID p, int nostop)
2 pj 205
{
206
  TBS_level_des *lev = (TBS_level_des *)(level_table[l]);
207
 
208
  /* there is at least one task ready inserted in an EDF or similar
209
     level */
210
 
211
  level_table[ lev->scheduling_level ]->
38 pj 212
    private_dispatch(lev->scheduling_level,p,nostop);
2 pj 213
}
214
 
38 pj 215
static void TBS_public_epilogue(LEVEL l, PID p)
2 pj 216
{
217
  TBS_level_des *lev = (TBS_level_des *)(level_table[l]);
218
 
219
  /* check if the wcet is finished... */
220
  if ((lev->flags & TBS_ENABLE_WCET_CHECK) && proc_table[p].avail_time <= 0) {
221
    /* if it is, raise a XWCET_VIOLATION exception */
222
    kern_raise(XWCET_VIOLATION,p);
223
    proc_table[p].status = TBS_WCET_VIOLATED;
224
 
225
    /* the current task have to die in the scheduling queue, and another
226
       have to be put in place... this code is identical to the
227
       TBS_task_end */
228
    level_table[ lev->scheduling_level ]->
38 pj 229
      private_extract(lev->scheduling_level,p);
2 pj 230
 
231
    /* we reclaim an avail time that can be <0 due to the timer
232
       approximations -> we have to postpone the deadline a little!
233
       we can use the ADDUSEC2TIMESPEC because the time postponed is
234
       less than 55ms */
235
    ADDUSEC2TIMESPEC((-proc_table[p].avail_time * lev->band_den)
236
                     / lev->band_num, &lev->lastdline);
237
 
238
    #ifdef TBS_TEST
239
    kern_printf("TBS_task_epilogue: Deadline posponed to %ds %dns\n",
240
              lev->lastdline.tv_sec, lev->lastdline.tv_nsec);
241
    #endif
242
 
29 pj 243
    lev->activated = iq_getfirst(&lev->wait);
2 pj 244
    if (lev->activated != NIL)
245
      TBS_activation(lev);
246
  }
247
  else
248
    /* the task has been preempted. it returns into the ready queue by
249
       calling the guest_epilogue... */
250
    level_table[ lev->scheduling_level ]->
38 pj 251
      private_epilogue(lev->scheduling_level,p);
2 pj 252
}
253
 
38 pj 254
static void TBS_public_activate(LEVEL l, PID p)
2 pj 255
{
256
  TBS_level_des *lev = (TBS_level_des *)(level_table[l]);
38 pj 257
  struct timespec t;
2 pj 258
 
259
  if (proc_table[p].status == SLEEP ||
260
       proc_table[p].status == TBS_WCET_VIOLATED) {
261
 
38 pj 262
    kern_gettime(&t);
263
    if (TIMESPEC_A_GT_B(&t, &lev->lastdline))
264
      TIMESPEC_ASSIGN(&lev->lastdline, &t );
265
 
266
 
2 pj 267
    if (lev->activated == NIL) {
268
      /* This is the first task in the level, so we activate it immediately */
269
      lev->activated = p;
270
      TBS_activation(lev);
271
    }
272
    else {
273
      proc_table[p].status = TBS_WAIT;
29 pj 274
      iq_insertlast(p, &lev->wait);
2 pj 275
    }
276
  }
277
  else if (lev->flag[p] & TBS_SAVE_ARRIVALS)
278
    lev->nact[p]++;
279
/*  else
280
    kern_printf("TBSREJ!!!");*/
281
}
282
 
38 pj 283
static void TBS_public_unblock(LEVEL l, PID p)
2 pj 284
{
285
  TBS_level_des *lev = (TBS_level_des *)(level_table[l]);
38 pj 286
  JOB_TASK_MODEL j;
2 pj 287
 
38 pj 288
  job_task_default_model(j,lev->lastdline);
289
  level_table[lev->scheduling_level]->
290
    private_insert(lev->scheduling_level,p,(TASK_MODEL *)&j);
2 pj 291
}
292
 
38 pj 293
static void TBS_public_block(LEVEL l, PID p)
2 pj 294
{
295
  TBS_level_des *lev = (TBS_level_des *)(level_table[l]);
296
 
297
  level_table[ lev->scheduling_level ]->
38 pj 298
    private_extract(lev->scheduling_level,p);
2 pj 299
}
300
 
38 pj 301
static int TBS_public_message(LEVEL l, PID p, void *m)
2 pj 302
{
303
  TBS_level_des *lev = (TBS_level_des *)(level_table[l]);
304
 
305
  /* a task activation is finished, but we are using a JOB_TASK_MODEL
306
     that implements a single activation, so we have to call
307
     the guest_end, that representsa single activation... */
308
  level_table[ lev->scheduling_level ]->
38 pj 309
    private_extract(lev->scheduling_level,p);
2 pj 310
 
311
  TBS_bandwidth_reclaiming(lev,p);
312
 
313
  /* we reset the capacity counters... */
314
  if (lev->flags & TBS_ENABLE_WCET_CHECK)
315
    proc_table[p].avail_time = proc_table[p].wcet;
316
 
317
  if (lev->nact[p]) {
318
    // lev->nact[p] can be >0 only if the SAVE_ARRIVALS bit is set
319
    lev->nact[p]--;
320
    proc_table[p].status = TBS_WAIT;
29 pj 321
    iq_insertlast(p, &lev->wait);
2 pj 322
  }
323
  else
324
    proc_table[p].status = SLEEP;
325
 
29 pj 326
  lev->activated = iq_getfirst(&lev->wait);
2 pj 327
  if (lev->activated != NIL)
328
    TBS_activation(lev);
329
 
38 pj 330
  jet_update_endcycle(); /* Update the Jet data... */
331
  trc_logevent(TRC_ENDCYCLE,&exec_shadow); /* tracer stuff */
332
 
333
  return 0;
2 pj 334
}
335
 
38 pj 336
static void TBS_public_end(LEVEL l, PID p)
2 pj 337
{
338
  TBS_level_des *lev = (TBS_level_des *)(level_table[l]);
339
 
340
  level_table[ lev->scheduling_level ]->
38 pj 341
    private_extract(lev->scheduling_level,p);
2 pj 342
 
343
  TBS_bandwidth_reclaiming(lev,p);
344
 
345
  proc_table[p].status = FREE;
29 pj 346
  iq_insertfirst(p,&freedesc);
2 pj 347
 
29 pj 348
  lev->activated = iq_getfirst(&lev->wait);
2 pj 349
  if (lev->activated != NIL)
350
    TBS_activation(lev);
351
}
352
 
353
/* Registration functions */
354
 
355
/*+ Registration function:
356
    int flags                 the init flags ... see TBS.h +*/
357
void TBS_register_level(int flags, LEVEL master, int num, int den)
358
{
359
  LEVEL l;            /* the level that we register */
360
  TBS_level_des *lev;  /* for readableness only */
361
  PID i;              /* a counter */
362
 
363
  printk("TBS_register_level\n");
364
 
365
  /* request an entry in the level_table */
38 pj 366
  l = level_alloc_descriptor(sizeof(TBS_level_des));
2 pj 367
 
38 pj 368
  lev = (TBS_level_des *)level_table[l];
2 pj 369
 
370
  printk("    lev=%d\n",(int)lev);
371
 
372
  /* fill the standard descriptor */
373
  if (flags & TBS_ENABLE_GUARANTEE)
38 pj 374
    lev->l.public_guarantee = TBS_public_guarantee;
2 pj 375
  else
38 pj 376
    lev->l.public_guarantee = NULL;
2 pj 377
 
38 pj 378
  lev->l.public_guarantee = TBS_public_guarantee;
379
  lev->l.public_create    = TBS_public_create;
380
  lev->l.public_end       = TBS_public_end;
381
  lev->l.public_dispatch  = TBS_public_dispatch;
382
  lev->l.public_epilogue  = TBS_public_epilogue;
383
  lev->l.public_activate  = TBS_public_activate;
384
  lev->l.public_unblock   = TBS_public_unblock;
385
  lev->l.public_block     = TBS_public_block;
386
  lev->l.public_message   = TBS_public_message;
2 pj 387
 
388
  /* fill the TBS descriptor part */
389
 
390
  for (i = 0; i < MAX_PROC; i++) {
391
    lev->nact[i] = 0;
392
    lev->flag[i] = 0;
393
  }
394
 
395
  NULL_TIMESPEC(&lev->lastdline);
396
 
29 pj 397
  iq_init(&lev->wait, &freedesc, 0);
2 pj 398
  lev->activated = NIL;
399
 
400
  lev->U = (MAX_BANDWIDTH / den) * num;
401
  lev->band_num = num;
402
  lev->band_den = den;
403
 
404
  lev->scheduling_level = master;
405
 
406
  lev->flags = flags & 0x07;
407
}
408
 
409
bandwidth_t TBS_usedbandwidth(LEVEL l)
410
{
411
  TBS_level_des *lev = (TBS_level_des *)(level_table[l]);
38 pj 412
 
413
  return lev->U;
2 pj 414
}
415
 
416
int TBS_get_nact(LEVEL l, PID p)
417
{
418
  TBS_level_des *lev = (TBS_level_des *)(level_table[l]);
38 pj 419
 
420
  return lev->nact[p];
2 pj 421
}
422