From 3057498a98914c809c58f828fbbd7bc061ee8a6d Mon Sep 17 00:00:00 2001
From: Bjoern Brandenburg <bbb@mpi-sws.org>
Date: Sun, 9 Aug 2015 13:18:52 +0200
Subject: Integrate LITMUS^RT scheduling class with sched_setscheduler

---
 kernel/sched/core.c | 34 ++++++++++++++++++++++++++++++++--
 1 file changed, 32 insertions(+), 2 deletions(-)

(limited to 'kernel')

diff --git a/kernel/sched/core.c b/kernel/sched/core.c
index 426f4e776188..1fe02e0e801c 100644
--- a/kernel/sched/core.c
+++ b/kernel/sched/core.c
@@ -91,6 +91,7 @@
 #include <litmus/ceiling.h>
 #include <litmus/trace.h>
 #include <litmus/sched_trace.h>
+#include <litmus/sched_plugin.h>
 
 #define CREATE_TRACE_POINTS
 #include <trace/events/sched.h>
@@ -3380,7 +3381,9 @@ static void __setscheduler(struct rq *rq, struct task_struct *p,
 	else
 		p->prio = normal_prio(p);
 
-	if (dl_prio(p->prio))
+	if (p->policy == SCHED_LITMUS)
+		p->sched_class = &litmus_sched_class;
+	else if (dl_prio(p->prio))
 		p->sched_class = &dl_sched_class;
 	else if (rt_prio(p->prio))
 		p->sched_class = &rt_sched_class;
@@ -3483,6 +3486,7 @@ static int __sched_setscheduler(struct task_struct *p,
 	const struct sched_class *prev_class;
 	struct rq *rq;
 	int reset_on_fork;
+	int litmus_task = 0;
 
 	/* may grab non-irq protected spin_locks */
 	BUG_ON(in_interrupt());
@@ -3497,7 +3501,7 @@ recheck:
 		if (policy != SCHED_DEADLINE &&
 				policy != SCHED_FIFO && policy != SCHED_RR &&
 				policy != SCHED_NORMAL && policy != SCHED_BATCH &&
-				policy != SCHED_IDLE)
+				policy != SCHED_IDLE && policy != SCHED_LITMUS)
 			return -EINVAL;
 	}
 
@@ -3515,6 +3519,8 @@ recheck:
 	if ((dl_policy(policy) && !__checkparam_dl(attr)) ||
 	    (rt_policy(policy) != (attr->sched_priority != 0)))
 		return -EINVAL;
+	if (policy == SCHED_LITMUS && policy == p->policy)
+		return -EINVAL;
 
 	/*
 	 * Allow unprivileged RT tasks to decrease priority:
@@ -3573,6 +3579,12 @@ recheck:
 			return retval;
 	}
 
+	if (policy == SCHED_LITMUS) {
+		retval = litmus_admit_task(p);
+		if (retval)
+			return retval;
+	}
+
 	/*
 	 * make sure no PI-waiters arrive (or leave) while we are
 	 * changing the priority of the task:
@@ -3656,6 +3668,11 @@ change:
 		return -EBUSY;
 	}
 
+	if (p->policy == SCHED_LITMUS) {
+		litmus_exit_task(p);
+		litmus_task = 1;
+	}
+
 	p->sched_reset_on_fork = reset_on_fork;
 	oldprio = p->prio;
 
@@ -3683,6 +3700,16 @@ change:
 	prev_class = p->sched_class;
 	__setscheduler(rq, p, attr, true);
 
+	if (policy == SCHED_LITMUS) {
+#ifdef CONFIG_SMP
+		p->rt_param.stack_in_use = running ? rq->cpu : NO_CPU;
+#else
+		p->rt_param.stack_in_use = running ? 0 : NO_CPU;
+#endif
+		p->rt_param.present = running;
+		litmus->task_new(p, queued, running);
+	}
+
 	if (running)
 		p->sched_class->set_curr_task(rq);
 	if (queued) {
@@ -3698,6 +3725,9 @@ change:
 
 	rt_mutex_adjust_pi(p);
 
+	if (litmus_task)
+		litmus_dealloc(p);
+
 	return 0;
 }
 
-- 
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