Small SMM fixups

[coreboot.git] / src / cpu / x86 / smm / smihandler.c

diff --git a/src/cpu/x86/smm/smihandler.c b/src/cpu/x86/smm/smihandler.c
index d44a3eae1b8b9f219f7bdfa51c69ecd67ff818d9..a6ab87fd65ecdebfadbd0203233069add3c969ae 100644 (file)
--- a/src/cpu/x86/smm/smihandler.c
+++ b/src/cpu/x86/smm/smihandler.c
@@ -28,7 +28,7 @@
 typedef enum { SMI_LOCKED, SMI_UNLOCKED } smi_semaphore;
 
 /* SMI multiprocessing semaphore */
-static volatile smi_semaphore smi_handler_status = SMI_UNLOCKED;
+static volatile smi_semaphore smi_handler_status __attribute__ ((aligned (4)))  = SMI_UNLOCKED;
 
 static int smi_obtain_lock(void)
 {
@@ -121,7 +121,11 @@ void smi_handler(u32 smm_revision)
                /* For security reasons we don't release the other CPUs
                 * until the CPU with the lock is actually done
                 */
-               while (smi_handler_status == SMI_LOCKED) /* wait */ ;
+               while (smi_handler_status == SMI_LOCKED) {
+                       asm volatile (
+                               ".byte 0xf3, 0x90\n"  /* hint a CPU we are in spinlock (PAUSE instruction, REP NOP) */
+                       );
+               }
                return;
        }