[PATCH] PPC: Don't sync timebase when inside VM

[Alexander Graf <agraf@suse.de>]

When running inside a virtual machine, we can not modify timebase, so
let's just not call the functions for it then.

This resolves hangs when booting e500 SMP guests on overcommitted hosts.

Reported-by: Stuart Yoder <B08248@freescale.com>
Signed-off-by: Alexander Graf <agraf@suse.de>
---
 arch/powerpc/platforms/85xx/smp.c |    7 +++++++
 1 files changed, 7 insertions(+), 0 deletions(-)

diff --git a/arch/powerpc/platforms/85xx/smp.c b/arch/powerpc/platforms/85xx/smp.c
index ff42490..d4b6c1f 100644
--- a/arch/powerpc/platforms/85xx/smp.c
+++ b/arch/powerpc/platforms/85xx/smp.c
@@ -249,6 +249,13 @@ void __init mpc85xx_smp_init(void)
 		smp_85xx_ops.cause_ipi = doorbell_cause_ipi;
 	}
 
+	/* When running under a hypervisor, we can not modify tb */
+	np = of_find_node_by_path("/hypervisor");
+	if (np) {
+		smp_85xx_ops.give_timebase = NULL;
+		smp_85xx_ops.take_timebase = NULL;
+	}
+
 	smp_ops = &smp_85xx_ops;
 
 #ifdef CONFIG_KEXEC
-- 
1.6.0.2