From 9282fe9cdbaeb1547112c8da13d6314620f194d4 Mon Sep 17 00:00:00 2001
From: Joseph Koshy <jkoshy@FreeBSD.org>
Date: Tue, 28 Mar 2006 14:09:21 +0000
Subject: [PATCH] Forcibly turn off all PMCs at module unload time.

MFC after:	1 week
---
 sys/dev/hwpmc/hwpmc_piv.c | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/sys/dev/hwpmc/hwpmc_piv.c b/sys/dev/hwpmc/hwpmc_piv.c
index f0701c8e7c35..1a98a3d338b0 100644
--- a/sys/dev/hwpmc/hwpmc_piv.c
+++ b/sys/dev/hwpmc/hwpmc_piv.c
@@ -674,6 +674,7 @@ p4_init(int cpu)
 static int
 p4_cleanup(int cpu)
 {
+	int i;
 	struct p4_cpu *pcs;
 
 	PMCDBG(MDP,INI,0, "p4-cleanup cpu=%d", cpu);
@@ -681,6 +682,11 @@ p4_cleanup(int cpu)
 	if ((pcs = (struct p4_cpu *) pmc_pcpu[cpu]) == NULL)
 		return 0;
 
+	/* Turn off all PMCs on this CPU */
+	for (i = 0; i < P4_NPMCS - 1; i++)
+		wrmsr(P4_CCCR_MSR_FIRST + i,
+		    rdmsr(P4_CCCR_MSR_FIRST + i) & ~P4_CCCR_ENABLE);
+
 	/*
 	 * If the CPU is physical we need to teardown the
 	 * full MD state.