+FORCEINLINE
+KIRQL
+MiAcquireExpansionLock(VOID)
+{
+ KIRQL OldIrql;
+
+ ASSERT(KeGetCurrentIrql() <= APC_LEVEL);
+ KeAcquireSpinLock(&MmExpansionLock, &OldIrql);
+ ASSERT(MiExpansionLockOwner == NULL);
+ MiExpansionLockOwner = PsGetCurrentThread();
+ return OldIrql;
+}
+
+FORCEINLINE
+VOID
+MiReleaseExpansionLock(KIRQL OldIrql)
+{
+ ASSERT(MiExpansionLockOwner == PsGetCurrentThread());
+ MiExpansionLockOwner = NULL;
+ KeReleaseSpinLock(&MmExpansionLock, OldIrql);
+ ASSERT(KeGetCurrentIrql() <= APC_LEVEL);
+}
+