From 6d449d27d9b974175ea30c8dfe3a388718c78183 Mon Sep 17 00:00:00 2001
From: Kip Macy <kmacy@FreeBSD.org>
Date: Fri, 2 Feb 2007 05:00:21 +0000
Subject: [PATCH] Add support for IPI_PREEMPT in order to enable use of the ULE
 scheduler

---
 sys/sun4v/include/intr_machdep.h |  1 +
 sys/sun4v/include/smp.h          |  3 +++
 sys/sun4v/sun4v/intr_machdep.c   |  4 +++-
 sys/sun4v/sun4v/mp_machdep.c     | 14 ++++++++++++++
 4 files changed, 21 insertions(+), 1 deletion(-)

diff --git a/sys/sun4v/include/intr_machdep.h b/sys/sun4v/include/intr_machdep.h
index 4c8111c7be9..9788e3904d7 100644
--- a/sys/sun4v/include/intr_machdep.h
+++ b/sys/sun4v/include/intr_machdep.h
@@ -46,6 +46,7 @@
 #define	PIL_RENDEZVOUS	3	/* smp rendezvous ipi */
 #define	PIL_AST		4	/* ast ipi */
 #define	PIL_STOP	5	/* stop cpu ipi */
+#define	PIL_PREEMPT	6	/* preempt idle thread cpu ipi */
 #define	PIL_FAST	13	/* fast interrupts */
 #define	PIL_TICK	14
 
diff --git a/sys/sun4v/include/smp.h b/sys/sun4v/include/smp.h
index b562c2b470e..73359814d41 100644
--- a/sys/sun4v/include/smp.h
+++ b/sys/sun4v/include/smp.h
@@ -44,6 +44,8 @@
 #define	IPI_AST		PIL_AST
 #define	IPI_RENDEZVOUS	PIL_RENDEZVOUS
 #define	IPI_STOP	PIL_STOP
+#define IPI_PREEMPT     PIL_PREEMPT
+
 
 #define	IPI_RETRIES	5000
 
@@ -79,6 +81,7 @@ void	cpu_ipi_send(u_int mid, u_long d0, u_long d1, u_long d2);
 
 void cpu_ipi_ast(struct trapframe *tf);
 void cpu_ipi_stop(struct trapframe *tf);
+void cpu_ipi_preempt(struct trapframe *tf);
 
 void	ipi_selected(u_int cpus, u_int ipi);
 void	ipi_all(u_int ipi);
diff --git a/sys/sun4v/sun4v/intr_machdep.c b/sys/sun4v/sun4v/intr_machdep.c
index edb5efe2dd1..6f17a698240 100644
--- a/sys/sun4v/sun4v/intr_machdep.c
+++ b/sys/sun4v/sun4v/intr_machdep.c
@@ -114,7 +114,8 @@ static char *pil_names[] = {
 	"rndzvs",	/* PIL_RENDEZVOUS */
 	"ast",		/* PIL_AST */
 	"stop",		/* PIL_STOP */
-	"stray", "stray", "stray", "stray", "stray", "stray", "stray",
+	"preempt",      /* PIL_PREEMPT */
+	"stray", "stray", "stray", "stray", "stray", "stray",
 	"fast",		/* PIL_FAST */
 	"tick",		/* PIL_TICK */
 };
@@ -266,6 +267,7 @@ intr_init(void)
 	intr_handlers[PIL_AST] = cpu_ipi_ast;
 	intr_handlers[PIL_RENDEZVOUS] = (ih_func_t *)smp_rendezvous_action;
 	intr_handlers[PIL_STOP]= cpu_ipi_stop;
+	intr_handlers[PIL_PREEMPT]= cpu_ipi_preempt;
 #endif
 	mtx_init(&intr_table_lock, "intr table", NULL, MTX_SPIN);
 	cpu_intrq_alloc();
diff --git a/sys/sun4v/sun4v/mp_machdep.c b/sys/sun4v/sun4v/mp_machdep.c
index d3cea9d13d7..e9c7d435f45 100644
--- a/sys/sun4v/sun4v/mp_machdep.c
+++ b/sys/sun4v/sun4v/mp_machdep.c
@@ -455,6 +455,20 @@ cpu_ipi_stop(struct trapframe *tf)
 	CTR1(KTR_SMP, "cpu_ipi_stop: restarted %d", curcpu);
 }
 
+void
+cpu_ipi_preempt(struct trapframe *tf)
+{
+	struct thread *running_thread = curthread;
+
+	mtx_lock_spin(&sched_lock);
+	if (running_thread->td_critnest > 1)
+		running_thread->td_owepreempt = 1;
+	else
+		mi_switch(SW_INVOL | SW_PREEMPT, NULL);
+	mtx_unlock_spin(&sched_lock);
+
+}
+
 void
 cpu_ipi_selected(int cpu_count, uint16_t *cpulist, u_long d0, u_long d1, u_long d2, uint64_t *ackmask)
 {
-- 
2.45.2