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/*
* Project: S.Ha.R.K.
*
* Coordinators:
* Giorgio Buttazzo <giorgio@sssup.it>
* Paolo Gai <pj@gandalf.sssup.it>
*
* Authors :
* Paolo Gai <pj@gandalf.sssup.it>
* Massimiliano Giorgi <massy@gandalf.sssup.it>
* Luca Abeni <luca@gandalf.sssup.it>
* Giacomo Guidi <giacomo@gandalf.sssup.it>
* (see the web pages for full authors list)
*
* ReTiS Lab (Scuola Superiore S.Anna - Pisa - Italy)
*
* http://www.sssup.it
* http://retis.sssup.it
* http://shark.sssup.it
*/
/*
* Copyright (C) 2000 Paolo Gai
*
* 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 2 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, write to the Free Software
* Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
*
*/
#include <hardcbs/hardcbs/hardcbs.h>
#include <arch/stdio.h>
#include <arch/string.h>
#include <kernel/model.h>
#include <kernel/descr.h>
#include <kernel/var.h>
#include <kernel/func.h>
#include <tracer.h>
/*+ Status used in the level +*/
#define HCBS_IDLE APER_STATUS_BASE /*+ waiting the activation +*/
#define HCBS_ZOMBIE APER_STATUS_BASE+1 /*+ waiting the period end +*/
/*+ task flags +*/
#define HCBS_SAVE_ARRIVALS 1
#define HCBS_APERIODIC 2
#define HCBS_SLEEP 4
#define HCBS_OVERLOAD 8
/*+ the level redefinition for the Total Bandwidth Server level +*/
typedef struct {
level_des l; /*+ the standard level descriptor +*/
/* The wcet are stored in the task descriptor, but we need
an array for the deadlines. We can't use the timespec_priority
field because it is used by the master level!!!...
Notice that however the use of the timespec_priority field
does not cause any problem... */
struct timespec cbs_dline[MAX_PROC]; /*+ CBS deadlines +*/
TIME period[MAX_PROC]; /*+ CBS activation period +*/
struct timespec reactivation_time[MAX_PROC];
/*+ the time at witch the reactivation timer is post +*/
int reactivation_timer[MAX_PROC];
/*+ the recativation timer +*/
int nact[MAX_PROC]; /*+ number of pending activations +*/
BYTE flag[MAX_PROC]; /*+ task flags +*/
int flags; /*+ the init flags... +*/
bandwidth_t U; /*+ the used bandwidth by the server +*/
LEVEL scheduling_level;
} HCBS_level_des;
static void HCBS_activation(HCBS_level_des *lev,
PID p,
struct timespec *acttime)
{
JOB_TASK_MODEL job;
/* we have to check if the deadline and the wcet are correct before
activating a new task or an old task... */
/* check 1: if the deadline is before than the actual scheduling time */
/* check 2: if ( avail_time >= (cbs_dline - acttime)* (wcet/period) )
(rule 7 in the CBS article!) */
TIME t;
struct timespec t2,t3;
t = (lev->period[p] * proc_table[p].avail_time) / proc_table[p].wcet;
t3.tv_sec = t / 1000000;
t3.tv_nsec = (t % 1000000) * 1000;
SUBTIMESPEC(&lev->cbs_dline[p], acttime, &t2);
if (/* 1 */ TIMESPEC_A_LT_B(&lev->cbs_dline[p], acttime) ||
/* 2 */ TIMESPEC_A_GT_B(&t3, &t2) ) {
/* if (TIMESPEC_A_LT_B(&lev->cbs_dline[p], acttime) )
kern_printf("$");
else
kern_printf("(Ûdline%d.%d act%d.%d wcet%d per%d avail%dÛ)",
lev->cbs_dline[p].tv_sec,lev->cbs_dline[p].tv_nsec/1000,
acttime->tv_sec, acttime->tv_nsec/1000,
proc_table[p].wcet, lev->period[p], proc_table[p].avail_time);
*/ /* we modify the deadline ... */
TIMESPEC_ASSIGN(&lev->cbs_dline[p], acttime);
ADDUSEC2TIMESPEC(lev->period[p], &lev->cbs_dline[p]);
/* and the capacity */
proc_table[p].avail_time = proc_table[p].wcet;
}
/* and, finally, we reinsert the task in the master level */
job_task_default_model(job, lev->cbs_dline[p]);
job_task_def_noexc(job);
level_table[ lev->scheduling_level ]->
private_insert(lev->scheduling_level, p, (TASK_MODEL *)&job);
}
static void HCBS_reload(HCBS_level_des *lev, PID p)
{
proc_table[p].avail_time += proc_table[p].wcet;
}
static void HCBS_avail_time_check(HCBS_level_des *lev, PID p)
{
/* Only one time due to hard reservation */
if (proc_table[p].avail_time < 0)
ADDUSEC2TIMESPEC(lev->period[p], &lev->cbs_dline[p]);
}
/* this is the periodic reactivation of the task... it is posted only
if the task is a periodic task */
static void HCBS_timer_reactivate(void *par)
{
PID p = (PID) par;
HCBS_level_des *lev;
lev = (HCBS_level_des *)level_table[proc_table[p].task_level];
if (lev->flag[p] & HCBS_SLEEP && proc_table[p].status == HCBS_IDLE) {
proc_table[p].status = SLEEP;
proc_table[p].avail_time = proc_table[p].wcet;
NULL_TIMESPEC(&lev->cbs_dline[p]);
return;
}
/* Hard reservation avail_time reload */
HCBS_reload(lev, p);
if (proc_table[p].status == HCBS_IDLE) {
/* the task has finished the current activation and must be
reactivated */
HCBS_activation(lev,p,&lev->reactivation_time[p]);
event_need_reschedule();
}
else if (lev->flag[p] & HCBS_SAVE_ARRIVALS)
/* the task has not completed the current activation, so we save
the activation incrementing nact... */
lev->nact[p]++;
if (!(lev->flag[p] & HCBS_APERIODIC)) {
/* repost the event at the next period end... */
ADDUSEC2TIMESPEC(lev->period[p], &lev->reactivation_time[p]);
lev->reactivation_timer[p] = kern_event_post(&lev->reactivation_time[p],
HCBS_timer_reactivate,
(void *)p);
}
/* tracer stuff */
TRACER_LOGEVENT(FTrace_EVT_task_timer,(unsigned short int)proc_table[p].context,(unsigned int)proc_table[p].task_level);
}
/*+ this function is called when a killed or ended task reach the
period end +*/
static void HCBS_timer_zombie(void *par)
{
PID p = (PID) par;
HCBS_level_des *lev;
lev = (HCBS_level_des *)level_table[proc_table[p].task_level];
/* we finally put the task in the ready queue */
proc_table[p].status = FREE;
iq_insertfirst(p,&freedesc);
}
/* The on-line guarantee is enabled only if the appropriate flag is set... */
static int HCBS_public_guarantee(LEVEL l, bandwidth_t *freebandwidth)
{
HCBS_level_des *lev = (HCBS_level_des *)(level_table[l]);
if (*freebandwidth >= lev->U) {
*freebandwidth -= lev->U;
return 1;
}
else
return 0;
}
static int HCBS_public_create(LEVEL l, PID p, TASK_MODEL *m)
{
HCBS_level_des *lev = (HCBS_level_des *)(level_table[l]);
SOFT_TASK_MODEL *soft;
if (m->pclass != SOFT_PCLASS) return -1;
if (m->level != 0 && m->level != l) return -1;
soft = (SOFT_TASK_MODEL *)m;
if (!(soft->met && soft->period)) return -1;
soft = (SOFT_TASK_MODEL *)m;
if (lev->flags & HCBS_ENABLE_GUARANTEE) {
bandwidth_t b;
b = (MAX_BANDWIDTH / soft->period) * soft->met;
/* really update lev->U, checking an overflow... */
if (MAX_BANDWIDTH - lev->U > b)
lev->U += b;
else
return -1;
}
/* Enable wcet check */
proc_table[p].avail_time = soft->met;
proc_table[p].wcet = soft->met;
proc_table[p].control |= CONTROL_CAP;
lev->nact[p] = 0;
lev->period[p] = soft->period;
NULL_TIMESPEC(&lev->cbs_dline[p]);
if (soft->periodicity == APERIODIC)
lev->flag[p] = HCBS_APERIODIC;
else
lev->flag[p] = 0;
if (soft->arrivals == SAVE_ARRIVALS)
lev->flag[p] |= HCBS_SAVE_ARRIVALS;
return 0; /* OK, also if the task cannot be guaranteed... */
}
static void HCBS_public_detach(LEVEL l, PID p)
{
/* the CBS level doesn't introduce any dinamic allocated new field.
we have only to decrement the allocated bandwidth */
HCBS_level_des *lev = (HCBS_level_des *)(level_table[l]);
if (lev->flags & HCBS_ENABLE_GUARANTEE) {
lev->U -= (MAX_BANDWIDTH / lev->period[p]) * proc_table[p].wcet;
}
}
static int HCBS_public_eligible(LEVEL l, PID p)
{
HCBS_level_des *lev = (HCBS_level_des *)(level_table[l]);
JOB_TASK_MODEL job;
/* we have to check if the deadline and the wcet are correct...
if the CBS level schedules in background with respect to others
levels, there can be the case in witch a task is scheduled by
schedule_time > CBS_deadline; in this case (not covered in the
article because if there is only the standard scheduling policy
this never apply) we reassign the deadline */
if ( TIMESPEC_A_LT_B(&lev->cbs_dline[p], &schedule_time) ) {
/* we kill the current activation */
level_table[ lev->scheduling_level ]->
private_extract(lev->scheduling_level, p);
/* we modify the deadline ... */
TIMESPEC_ASSIGN(&lev->cbs_dline[p], &schedule_time);
ADDUSEC2TIMESPEC(lev->period[p], &lev->cbs_dline[p]);
/* and the capacity */
proc_table[p].avail_time = proc_table[p].wcet;
/* and, finally, we reinsert the task in the master level */
job_task_default_model(job, lev->cbs_dline[p]);
job_task_def_noexc(job);
level_table[ lev->scheduling_level ]->
private_insert(lev->scheduling_level, p, (TASK_MODEL *)&job);
return -1;
}
return 0;
}
static void HCBS_public_dispatch(LEVEL l, PID p, int nostop)
{
HCBS_level_des *lev = (HCBS_level_des *)(level_table[l]);
level_table[ lev->scheduling_level ]->
private_dispatch(lev->scheduling_level,p,nostop);
}
static void HCBS_public_epilogue(LEVEL l, PID p)
{
HCBS_level_des *lev = (HCBS_level_des *)(level_table[l]);
/* check if the wcet is finished... */
if ( proc_table[p].avail_time <= 0) {
/* Set the overload flag */
lev->flag[p] |= HCBS_OVERLOAD;
/* we kill the current activation */
level_table[ lev->scheduling_level ]->
private_extract(lev->scheduling_level, p);
/* we modify the deadline according to rule 4 ... */
HCBS_avail_time_check(lev, p);
/* Hard Reservation: The avail_time will be reloaded in the
next reactivation event. The task is suspended */
proc_table[p].status = HCBS_IDLE;
if (lev->flag[p] & HCBS_APERIODIC) {
ADDUSEC2TIMESPEC(lev->period[p], &lev->reactivation_time[p]);
lev->reactivation_timer[p] = kern_event_post(&lev->reactivation_time[p],
HCBS_timer_reactivate,
(void *)p);
}
}
else
/* the task has been preempted. it returns into the ready queue by
calling the guest_epilogue... */
level_table[ lev->scheduling_level ]->
private_epilogue(lev->scheduling_level,p);
}
static void HCBS_public_activate(LEVEL l, PID p, struct timespec *t)
{
HCBS_level_des *lev = (HCBS_level_des *)(level_table[l]);
if (lev->flag[p] & HCBS_SLEEP) {
lev->flag[p] &= ~HCBS_SLEEP;
if (proc_table[p].status != SLEEP) return;
}
/* save activation (only if needed... */
if (proc_table[p].status != SLEEP) {
if (lev->flag[p] & HCBS_SAVE_ARRIVALS)
lev->nact[p]++;
return;
}
HCBS_activation(lev, p, t);
/* Set the reactivation timer */
if (!(lev->flag[p] & HCBS_APERIODIC))
{
/* we cannot use the deadline computed by CBS_activation because
the deadline may be != from actual_time + period
(if we call the task_activate after a task_sleep, and the
deadline was postponed a lot...) */
TIMESPEC_ASSIGN(&lev->reactivation_time[p], t);
ADDUSEC2TIMESPEC(lev->period[p], &lev->reactivation_time[p]);
// TIMESPEC_ASSIGN(&lev->reactivation_time[p], &lev->cbs_dline[p]);
lev->reactivation_timer[p] = kern_event_post(&lev->reactivation_time[p],
HCBS_timer_reactivate,
(void *)p);
}
// kern_printf("act : %d %d |",lev->cbs_dline[p].tv_nsec/1000,p);
}
static void HCBS_public_unblock(LEVEL l, PID p)
{
HCBS_level_des *lev = (HCBS_level_des *)(level_table[l]);
struct timespec acttime;
kern_gettime(&acttime);
HCBS_activation(lev,p,&acttime);
}
static void HCBS_public_block(LEVEL l, PID p)
{
HCBS_level_des *lev = (HCBS_level_des *)(level_table[l]);
/* check if the wcet is finished... */
HCBS_avail_time_check(lev, p);
level_table[ lev->scheduling_level ]->
private_extract(lev->scheduling_level,p);
}
static int HCBS_public_message(LEVEL l, PID p, void *m)
{
HCBS_level_des *lev = (HCBS_level_des *)(level_table[l]);
HCBS_command_message *msg;
switch((long)(m)) {
case (long)(NULL):
/* check if the wcet is finished... */
HCBS_avail_time_check(lev, p);
if (lev->flag[p] & HCBS_OVERLOAD) {
lev->nact[p]++;
lev->flag[p] &= ~HCBS_OVERLOAD;
}
if (lev->nact[p]) {
/* continue!!!! */
lev->nact[p]--;
level_table[ lev->scheduling_level ]->
private_epilogue(lev->scheduling_level,p);
} else {
level_table[ lev->scheduling_level ]->
private_extract(lev->scheduling_level,p);
if (lev->flag[p] & HCBS_APERIODIC)
proc_table[p].status = SLEEP;
else /* the task is soft_periodic */
proc_table[p].status = HCBS_IDLE;
}
jet_update_endcycle(); /* Update the Jet data... */
TRACER_LOGEVENT(FTrace_EVT_task_end_cycle,(unsigned short int)proc_table[p].context,(unsigned int)l);
break;
case 1:
lev->flag[p] |= HCBS_SLEEP;
TRACER_LOGEVENT(FTrace_EVT_task_disable,(unsigned short int)proc_table[p].context,(unsigned int)l);
break;
/* Set/Get Met/Period */
default:
msg = (HCBS_command_message *)(m);
switch (msg->command) {
case HCBS_SET_PERIOD:
lev->U -= (bandwidth_t)(MAX_BANDWIDTH / lev->period[p]
* proc_table[p].wcet);
lev->period[p] = msg->param;
lev->U += (bandwidth_t)(MAX_BANDWIDTH / lev->period[p]
* proc_table[p].wcet);
break;
case HCBS_GET_PERIOD:
msg->param = lev->period[p];
break;
case HCBS_SET_MET:
lev->U -= (bandwidth_t)(MAX_BANDWIDTH / lev->period[p]
* proc_table[p].wcet);
proc_table[p].wcet = msg->param;
lev->U += (bandwidth_t)(MAX_BANDWIDTH / lev->period[p]
* proc_table[p].wcet);
break;
case HCBS_GET_MET:
msg->param = proc_table[p].wcet;
break;
}
}
return 0;
}
static void HCBS_public_end(LEVEL l, PID p)
{
HCBS_level_des *lev = (HCBS_level_des *)(level_table[l]);
/* check if the wcet is finished... */
HCBS_avail_time_check(lev, p);
level_table[ lev->scheduling_level ]->
private_extract(lev->scheduling_level,p);
/* and free the allocated bandwidth */
lev->U -= (MAX_BANDWIDTH/lev->period[p]) * proc_table[p].wcet;
/* we delete the reactivation timer */
if (!(lev->flag[p] & HCBS_APERIODIC) ||
(lev->flag[p] & HCBS_APERIODIC && lev->flag[p] & HCBS_OVERLOAD)) {
kern_event_delete(lev->reactivation_timer[p]);
lev->reactivation_timer[p] = -1;
}
/* Finally, we post the zombie event. when the end period is reached,
the task descriptor and banwidth are freed */
proc_table[p].status = HCBS_ZOMBIE;
lev->reactivation_timer[p] = kern_event_post(&lev->cbs_dline[p],
HCBS_timer_zombie,
(void *)p);
}
/* Registration functions */
/*+ Registration function:
int flags the init flags ... see CBS.h +*/
LEVEL HCBS_register_level(int flags, LEVEL master)
{
LEVEL l; /* the level that we register */
HCBS_level_des *lev; /* for readableness only */
PID i; /* a counter */
printk("HCBS_register_level\n");
/* request an entry in the level_table */
l = level_alloc_descriptor(sizeof(HCBS_level_des));
lev = (HCBS_level_des *)level_table[l];
/* fill the standard descriptor */
if (flags & HCBS_ENABLE_GUARANTEE)
lev->l.public_guarantee = HCBS_public_guarantee;
else
lev->l.public_guarantee = NULL;
lev->l.public_create = HCBS_public_create;
lev->l.public_detach = HCBS_public_detach;
lev->l.public_end = HCBS_public_end;
lev->l.public_eligible = HCBS_public_eligible;
lev->l.public_dispatch = HCBS_public_dispatch;
lev->l.public_epilogue = HCBS_public_epilogue;
lev->l.public_activate = HCBS_public_activate;
lev->l.public_unblock = HCBS_public_unblock;
lev->l.public_block = HCBS_public_block;
lev->l.public_message = HCBS_public_message;
/* fill the CBS descriptor part */
for (i=0; i<MAX_PROC; i++) {
NULL_TIMESPEC(&lev->cbs_dline[i]);
lev->period[i] = 0;
NULL_TIMESPEC(&lev->reactivation_time[i]);
lev->reactivation_timer[i] = -1;
lev->nact[i] = 0;
lev->flag[i] = 0;
}
lev->U = 0;
lev->scheduling_level = master;
lev->flags = flags;
return l;
}
bandwidth_t HCBS_usedbandwidth(LEVEL l)
{
HCBS_level_des *lev = (HCBS_level_des *)(level_table[l]);
return lev->U;
}
int HCBS_get_nact(LEVEL l, PID p)
{
HCBS_level_des *lev = (HCBS_level_des *)(level_table[l]);
return lev->nact[p];
}