static inline unsigned long long get_cpu_usecs()
{
struct timespec ts = {0, 0};
clock_gettime(CLOCK_MONOTONIC, &ts);
return timespec_to_usecs(&ts);
}
/**
* RESCH APIs are called through write() system call.
* See api.h for details.
* Do not use timespec_to_jiffies(), since it rounds up the value.
*/
static ssize_t resch_write
(struct file *file, const char *buf, size_t count, loff_t *offset)
{
int res = RES_SUCCESS;
struct api_struct a;
unsigned long us;
/* copy data to kernel buffer. */
if (copy_from_user(&a, buf, count)) {
printk(KERN_WARNING "RESCH: failed to copy data.\n");
return -EFAULT;
}
switch (a.api) {
/* PORT I: preemptive periodic real-time scheduling.*/
case API_INIT:
res = api_init();
break;
case API_EXIT:
res = api_exit(a.rid);
break;
case API_RUN:
us = timespec_to_usecs(&a.arg.ts);
res = api_run(a.rid, usecs_to_jiffies(us));
break;
case API_WAIT_PERIOD:
res = api_wait_for_period(a.rid);
break;
case API_WAIT_INTERVAL:
us = timespec_to_usecs(&a.arg.ts);
res = api_wait_for_interval(a.rid, usecs_to_jiffies(us));
break;
case API_SET_PERIOD:
us = timespec_to_usecs(&a.arg.ts);
res = api_set_period(a.rid, usecs_to_jiffies(us));
break;
case API_SET_DEADLINE:
us = timespec_to_usecs(&a.arg.ts);
res = api_set_deadline(a.rid, usecs_to_jiffies(us));
break;
case API_SET_WCET:
us = timespec_to_usecs(&a.arg.ts);
res = api_set_wcet(a.rid, us);
break;
case API_SET_RUNTIME:
us = timespec_to_usecs(&a.arg.ts);
res = api_set_runtime(a.rid, us);
break;
case API_SET_PRIORITY:
res = api_set_priority(a.rid, a.arg.val);
break;
case API_SET_SCHEDULER:
res = api_set_scheduler(a.rid, a.arg.val);
break;
case API_BACKGROUND:
res = api_background(a.rid);
break;
/* PORT II: event-driven asynchrous scheduling.*/
case API_SLEEP:
us = timespec_to_usecs(&a.arg.ts);
res = api_sleep(a.rid, usecs_to_jiffies(us));
break;
case API_SUSPEND:
res = api_suspend(a.rid);
break;
case API_WAKE_UP:
res = api_wake_up(a.arg.val);
break;
/* PORT III: reservation-based scheduling.*/
case API_RESERVE_START:
us = timespec_to_usecs(&a.arg.ts);
res = api_reserve_start(a.rid, usecs_to_jiffies(us), false);
break;
case API_RESERVE_START_XCPU:
us = timespec_to_usecs(&a.arg.ts);
res = api_reserve_start(a.rid, usecs_to_jiffies(us), true);
break;
case API_RESERVE_STOP:
res = api_reserve_stop(a.rid);
break;
case API_RESERVE_EXPIRE:
res = api_reserve_expire(a.rid);
break;
case API_SERVER_RUN:
res = api_server_run(a.rid);
break;
/* PORT IV.*/
/* PORT V: hierarchical scheduling.*/
case API_COMPONENT_CREATE:
res = api_component_create();
break;
case API_COMPONENT_DESTROY:
res = api_component_destroy(a.arg.val);
break;
case API_COMPOSE:
res = api_compose(a.rid, a.arg.val);
break;
case API_DECOMPOSE:
res = api_decompose(a.rid);
break;
default: /* illegal api identifier. */
res = RES_ILLEGAL;
printk(KERN_WARNING "RESCH: illegal API identifier.\n");
break;
}
return res;
}
