powerpc/85xx: disable timebase synchronization under the hypervisor

The Freescale hypervisor does not allow guests to write to the timebase
registers (virtualizing the timebase register was deemed too complicated),
so don't try to synchronize the timebase registers when we're running
under the hypervisor.

This typically happens when kexec support is enabled.

Signed-off-by: Timur Tabi <timur@freescale.com>
Signed-off-by: Kumar Gala <galak@kernel.crashing.org>

1 files changed, 11 insertions, 0 deletions

diff --git a/arch/powerpc/platforms/85xx/p3041_ds.c b/arch/powerpc/platforms/85xx/p3041_ds.c
index 1fcd233a9167..96d99a374dcf 100644
--- a/arch/powerpc/platforms/85xx/p3041_ds.c
+++ b/arch/powerpc/platforms/85xx/p3041_ds.c
@@ -40,6 +40,9 @@
 static int __init p3041_ds_probe(void)
 {
         unsigned long root = of_get_flat_dt_root();
+#ifdef CONFIG_SMP
+        extern struct smp_ops_t smp_85xx_ops;
+#endif
 
         if (of_flat_dt_is_compatible(root, "fsl,P3041DS"))
                 return 1;
@@ -51,6 +54,14 @@ static int __init p3041_ds_probe(void)
                 ppc_md.restart = fsl_hv_restart;
                 ppc_md.power_off = fsl_hv_halt;
                 ppc_md.halt = fsl_hv_halt;
+#ifdef CONFIG_SMP
+                /*
+                 * Disable the timebase sync operations because we can't write
+                 * to the timebase registers under the hypervisor.
+                  */
+                smp_85xx_ops.give_timebase = NULL;
+                smp_85xx_ops.take_timebase = NULL;
+#endif
                 return 1;
         }