fast-reboot: add more barriers around cpu state changes

This is a bit of paranoia, but when a CPU changes state to signal it
has reached a particular point, all previous stores should be visible.

Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Stewart Smith <stewart@linux.vnet.ibm.com>

1 files changed, 3 insertions, 0 deletions

diff --git a/core/cpu.c b/core/cpu.c
index d079110..2dba2f5 100644
--- a/core/cpu.c
+++ b/core/cpu.c
@@ -1126,7 +1126,10 @@ void cpu_bringup(void)
 
 void cpu_callin(struct cpu_thread *cpu)
 {
+	sync();
 	cpu->state = cpu_state_active;
+	sync();
+
 	cpu->job_has_no_return = false;
 
 	init_hid();