ARMv8: add the secure monitor firmware framework

This framework is introduced for ARMv8 secure monitor mode firmware.
The main functions of the framework are, on EL3, verify the firmware,
load it to the secure memory and jump into it, and while it returned
to U-Boot, do some necessary setups at the 'target exception level'
that is determined by the respective secure firmware.

So far, the framework support only FIT format image, and need to define
the name of which config node should be used in 'configurations' and
the name of property for the raw secure firmware image in that config.
The FIT image should be stored in Byte accessing memory, such as NOR
Flash, or else it should be copied to main memory to use this framework.

Signed-off-by: Hou Zhiqiang <Zhiqiang.Hou@nxp.com>
Reviewed-by: York Sun <york.sun@nxp.com>
diff --git a/arch/arm/cpu/armv8/sec_firmware_asm.S b/arch/arm/cpu/armv8/sec_firmware_asm.S
new file mode 100644
index 0000000..0c6a462
--- /dev/null
+++ b/arch/arm/cpu/armv8/sec_firmware_asm.S
@@ -0,0 +1,53 @@
+/*
+ * Copyright 2016 NXP Semiconductor, Inc.
+ *
+ * SPDX-License-Identifier:	GPL-2.0+
+ */
+
+#include <config.h>
+#include <linux/linkage.h>
+#include <asm/system.h>
+#include <asm/macro.h>
+
+WEAK(_sec_firmware_entry)
+	/*
+	 * x0: Secure Firmware entry point
+	 * x1: Exception return address Low
+	 * x2: Exception return address High
+	 */
+
+	/* Save stack pointer for EL2 */
+	mov	x3, sp
+	msr	sp_el2, x3
+
+	/* Set exception return address hold pointer */
+        adr	x4, 1f
+        mov	x3, x4
+#ifdef SEC_FIRMWARE_ERET_ADDR_REVERT
+        rev	w3, w3
+#endif
+        str	w3, [x1]
+        lsr	x3, x4, #32
+#ifdef SEC_FIRMWARE_ERET_ADDR_REVERT
+        rev	w3, w3
+#endif
+        str	w3, [x2]
+
+	/* Call SEC monitor */
+        br	x0
+
+1:
+        mov	x0, #0
+        ret
+ENDPROC(_sec_firmware_entry)
+
+#ifdef CONFIG_ARMV8_PSCI
+ENTRY(_sec_firmware_support_psci_version)
+	mov	x0, 0x84000000
+	mov	x1, 0x0
+	mov	x2, 0x0
+	mov	x3, 0x0
+	smc	#0
+	ret
+ENDPROC(_sec_firmware_support_psci_version)
+#endif