diff --git a/arch/ia64/sn/kernel/xpc.h b/arch/ia64/sn/kernel/xpc.h
index fbcedc7c27fa..5483a9f227d4 100644
--- a/arch/ia64/sn/kernel/xpc.h
+++ b/arch/ia64/sn/kernel/xpc.h
@@ -163,7 +163,7 @@ struct xpc_vars {
 	u8 version;
 	u64 heartbeat;
 	u64 heartbeating_to_mask;
-	u64 kdb_status;		/* 0 = machine running */
+	u64 heartbeat_offline;	/* if 0, heartbeat should be changing */
 	int act_nasid;
 	int act_phys_cpuid;
 	u64 vars_part_pa;
diff --git a/arch/ia64/sn/kernel/xpc_main.c b/arch/ia64/sn/kernel/xpc_main.c
index cece3c7c69be..b617236524c6 100644
--- a/arch/ia64/sn/kernel/xpc_main.c
+++ b/arch/ia64/sn/kernel/xpc_main.c
@@ -57,6 +57,7 @@
 #include <linux/reboot.h>
 #include <asm/sn/intr.h>
 #include <asm/sn/sn_sal.h>
+#include <asm/kdebug.h>
 #include <asm/uaccess.h>
 #include "xpc.h"
 
@@ -188,6 +189,11 @@ static struct notifier_block xpc_reboot_notifier = {
 	.notifier_call = xpc_system_reboot,
 };
 
+static int xpc_system_die(struct notifier_block *, unsigned long, void *);
+static struct notifier_block xpc_die_notifier = {
+	.notifier_call = xpc_system_die,
+};
+
 
 /*
  * Timer function to enforce the timelimit on the partition disengage request.
@@ -997,6 +1003,9 @@ xpc_do_exit(enum xpc_retval reason)
 	/* take ourselves off of the reboot_notifier_list */
 	(void) unregister_reboot_notifier(&xpc_reboot_notifier);
 
+	/* take ourselves off of the die_notifier list */
+	(void) unregister_die_notifier(&xpc_die_notifier);
+
 	/* close down protections for IPI operations */
 	xpc_restrict_IPI_ops();
 
@@ -1010,6 +1019,63 @@ xpc_do_exit(enum xpc_retval reason)
 }
 
 
+/*
+ * Called when the system is about to be either restarted or halted.
+ */
+static void
+xpc_die_disengage(void)
+{
+	struct xpc_partition *part;
+	partid_t partid;
+	unsigned long engaged;
+	long time, print_time, disengage_request_timeout;
+
+
+	/* keep xpc_hb_checker thread from doing anything (just in case) */
+	xpc_exiting = 1;
+
+	xpc_vars->heartbeating_to_mask = 0;  /* indicate we're deactivated */
+
+	for (partid = 1; partid < XP_MAX_PARTITIONS; partid++) {
+		part = &xpc_partitions[partid];
+
+		if (!XPC_SUPPORTS_DISENGAGE_REQUEST(part->
+							remote_vars_version)) {
+
+			/* just in case it was left set by an earlier XPC */
+			xpc_clear_partition_engaged(1UL << partid);
+			continue;
+		}
+
+		if (xpc_partition_engaged(1UL << partid) ||
+					part->act_state != XPC_P_INACTIVE) {
+			xpc_request_partition_disengage(part);
+			xpc_mark_partition_disengaged(part);
+			xpc_IPI_send_disengage(part);
+		}
+	}
+
+	print_time = rtc_time();
+	disengage_request_timeout = print_time +
+		(xpc_disengage_request_timelimit * sn_rtc_cycles_per_second);
+
+	/* wait for all other partitions to disengage from us */
+
+	while ((engaged = xpc_partition_engaged(-1UL)) &&
+			(time = rtc_time()) < disengage_request_timeout) {
+
+		if (time >= print_time) {
+			dev_info(xpc_part, "waiting for remote partitions to "
+				"disengage, engaged=0x%lx\n", engaged);
+			print_time = time + (XPC_DISENGAGE_PRINTMSG_INTERVAL *
+						sn_rtc_cycles_per_second);
+		}
+	}
+	dev_info(xpc_part, "finished waiting for remote partitions to "
+				"disengage, engaged=0x%lx\n", engaged);
+}
+
+
 /*
  * This function is called when the system is being rebooted.
  */
@@ -1038,6 +1104,33 @@ xpc_system_reboot(struct notifier_block *nb, unsigned long event, void *unused)
 }
 
 
+/*
+ * This function is called when the system is being rebooted.
+ */
+static int
+xpc_system_die(struct notifier_block *nb, unsigned long event, void *unused)
+{
+	switch (event) {
+	case DIE_MACHINE_RESTART:
+	case DIE_MACHINE_HALT:
+		xpc_die_disengage();
+		break;
+	case DIE_MCA_MONARCH_ENTER:
+	case DIE_INIT_MONARCH_ENTER:
+		xpc_vars->heartbeat++;
+		xpc_vars->heartbeat_offline = 1;
+		break;
+	case DIE_MCA_MONARCH_LEAVE:
+	case DIE_INIT_MONARCH_LEAVE:
+		xpc_vars->heartbeat++;
+		xpc_vars->heartbeat_offline = 0;
+		break;
+	}
+
+	return NOTIFY_DONE;
+}
+
+
 int __init
 xpc_init(void)
 {
@@ -1154,6 +1247,12 @@ xpc_init(void)
 		dev_warn(xpc_part, "can't register reboot notifier\n");
 	}
 
+	/* add ourselves to the die_notifier list (i.e., ia64die_chain) */
+	ret = register_die_notifier(&xpc_die_notifier);
+	if (ret != 0) {
+		dev_warn(xpc_part, "can't register die notifier\n");
+	}
+
 
 	/*
 	 * Set the beating to other partitions into motion.  This is
@@ -1179,6 +1278,9 @@ xpc_init(void)
 		/* take ourselves off of the reboot_notifier_list */
 		(void) unregister_reboot_notifier(&xpc_reboot_notifier);
 
+		/* take ourselves off of the die_notifier list */
+		(void) unregister_die_notifier(&xpc_die_notifier);
+
 		del_timer_sync(&xpc_hb_timer);
 		free_irq(SGI_XPC_ACTIVATE, NULL);
 		xpc_restrict_IPI_ops();
diff --git a/arch/ia64/sn/kernel/xpc_partition.c b/arch/ia64/sn/kernel/xpc_partition.c
index 581e113d2d37..cdd6431853a1 100644
--- a/arch/ia64/sn/kernel/xpc_partition.c
+++ b/arch/ia64/sn/kernel/xpc_partition.c
@@ -436,13 +436,13 @@ xpc_check_remote_hb(void)
 		}
 
 		dev_dbg(xpc_part, "partid = %d, heartbeat = %ld, last_heartbeat"
-			" = %ld, kdb_status = %ld, HB_mask = 0x%lx\n", partid,
-			remote_vars->heartbeat, part->last_heartbeat,
-			remote_vars->kdb_status,
+			" = %ld, heartbeat_offline = %ld, HB_mask = 0x%lx\n",
+			partid, remote_vars->heartbeat, part->last_heartbeat,
+			remote_vars->heartbeat_offline,
 			remote_vars->heartbeating_to_mask);
 
 		if (((remote_vars->heartbeat == part->last_heartbeat) &&
-			(remote_vars->kdb_status == 0)) ||
+			(remote_vars->heartbeat_offline == 0)) ||
 			     !xpc_hb_allowed(sn_partition_id, remote_vars)) {
 
 			XPC_DEACTIVATE_PARTITION(part, xpcNoHeartbeat);