stos/amd64: Add kernel fence helper

Signed-off-by: Chloe M. <chloe@mensia.org>
2026-06-23 18:59:57 +00:00
parent ec83f6c6a2
commit 3671c32532
1 changed files with 34 additions and 0 deletions
@@ -0,0 +1,34 @@
+/*
+ * Copyright (c) 2026, Chloe M.
+ * Provided under the BSD-3 clause.
+ *
+ * Description: Kernel entry fence
+ * Author:      Chloe M.
+ */
+
+#ifndef _MACHINE_KFENCE_H_
+#define _MACHINE_KFENCE_H_ 1
+
+/*
+ * Kernel fence for interrupt entries that do
+ * not have an error code
+ */
+#define KFENCE              \
+    testq $0x3, 8(%rsp)   ; \
+    jz 1f                 ; \
+    lfence                ; \
+    swapgs                ; \
+1:  nop
+
+/*
+ * Kernel fence for interrupt entries that
+ * have an error code
+ */
+#define KFENCE_EC           \
+    testq $0x3, 16(%rsp)  ; \
+    jz 1f                 ; \
+    lfence                ; \
+    swapgs                ; \
+1:  nop
+
+#endif  /* !_MACHINE_KFENCE_H_ */