arch/x86: Add function to determine if we're currently running from CAR

This patch adds a simple function that can be used to check if
CAR_GLOBALs are currently being read from CAR or from DRAM.

Change-Id: Ib7ad0896a691ef6e89e622b985417fedc43579c1
Signed-off-by: Julius Werner <jwerner@chromium.org>
Reviewed-on: https://review.coreboot.org/19787
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
Reviewed-by: Aaron Durbin <adurbin@chromium.org>
Reviewed-by: Philippe Mathieu-Daudé <philippe.mathieu.daude@gmail.com>

1 files changed, 5 insertions, 0 deletions

diff --git a/src/cpu/x86/car.c b/src/cpu/x86/car.c
index 606a35e2f6..1b02f8b7da 100644
--- a/src/cpu/x86/car.c
+++ b/src/cpu/x86/car.c
@@ -113,6 +113,11 @@ void *car_sync_var_ptr(void *var)
 	return mig_var;
 }
 
+int car_active(void)
+{
+	return !car_migrated;
+}
+
 static void do_car_migrate_variables(void)
 {
 	void *migrated_base;