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-rw-r--r--arch/arm/common/secure_cntvoff.S32
1 files changed, 32 insertions, 0 deletions
diff --git a/arch/arm/common/secure_cntvoff.S b/arch/arm/common/secure_cntvoff.S
new file mode 100644
index 000000000000..53fc7bdb6c2e
--- /dev/null
+++ b/arch/arm/common/secure_cntvoff.S
@@ -0,0 +1,32 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+/*
+ * Copyright (C) 2014 Renesas Electronics Corporation
+ *
+ * Initialization of CNTVOFF register from secure mode
+ *
+ */
+
+#include <linux/linkage.h>
+#include <asm/assembler.h>
+
+ENTRY(secure_cntvoff_init)
+ .arch armv7-a
+ /*
+ * CNTVOFF has to be initialized either from non-secure Hypervisor
+ * mode or secure Monitor mode with SCR.NS==1. If TrustZone is enabled
+ * then it should be handled by the secure code. The CPU must implement
+ * the virtualization extensions.
+ */
+ cps #MON_MODE
+ mrc p15, 0, r1, c1, c1, 0 /* Get Secure Config */
+ orr r0, r1, #1
+ mcr p15, 0, r0, c1, c1, 0 /* Set Non Secure bit */
+ isb
+ mov r0, #0
+ mcrr p15, 4, r0, r0, c14 /* CNTVOFF = 0 */
+ isb
+ mcr p15, 0, r1, c1, c1, 0 /* Set Secure bit */
+ isb
+ cps #SVC_MODE
+ ret lr
+ENDPROC(secure_cntvoff_init)