cobalt/sched: sporadic: add early parameter checking handler

Move parameter checks from sched_declare() to the new sched_chkparam()
handler, which runs early and unconditionally from
xnsched_set_policy().

Signed-off-by: Philippe Gerum <rpm@xenomai.org>
Signed-off-by: Jan Kiszka <jan.kiszka@siemens.com>

kernel/cobalt/sched-sporadic.c

@@ -290,11 +290,9 @@ static void xnsched_sporadic_protectprio(struct xnthread *thread, int prio)
 	thread->cprio = prio;
 }
 
-static int xnsched_sporadic_declare(struct xnthread *thread,
-				    const union xnsched_policy_param *p)
+static int xnsched_sporadic_chkparam(struct xnthread *thread,
+				     const union xnsched_policy_param *p)
 {
-	struct xnsched_sporadic_data *pss;
-
 	if (p->pss.low_prio != -1 &&
 	    (p->pss.low_prio < XNSCHED_SPORADIC_MIN_PRIO ||
 	     p->pss.low_prio > XNSCHED_SPORADIC_MAX_PRIO))
@@ -319,6 +317,14 @@ static int xnsched_sporadic_declare(struct xnthread *thread,
 	if (p->pss.max_repl < 1 || p->pss.max_repl > MAX_REPLENISH)
 		return -EINVAL;
 
+	return 0;
+}
+
+static int xnsched_sporadic_declare(struct xnthread *thread,
+				    const union xnsched_policy_param *p)
+{
+	struct xnsched_sporadic_data *pss;
+
 	pss = xnmalloc(sizeof(*pss));
 	if (pss == NULL)
 		return -ENOMEM;
@@ -535,6 +541,7 @@ struct xnsched_class xnsched_class_sporadic = {
 	.sched_tick		=	NULL,
 	.sched_rotate		=	NULL,
 	.sched_migrate		=	NULL,
+	.sched_chkparam		=	xnsched_sporadic_chkparam,
 	.sched_setparam		=	xnsched_sporadic_setparam,
 	.sched_getparam		=	xnsched_sporadic_getparam,
 	.sched_trackprio	=	xnsched_sporadic_trackprio,