RAS: Introduce handler for EL3 EAs

External Aborts while executing in EL3 is fatal in nature. This patch
allows for the platform to define a handler for External Aborts received
while executing in EL3. A default implementation is added which falls
back to platform unhandled exception.

Change-Id: I466f2c8113a33870f2c7d2d8f2bf20437d9fd354
Signed-off-by: Jeenu Viswambharan <jeenu.viswambharan@arm.com>
diff --git a/plat/common/aarch64/platform_helpers.S b/plat/common/aarch64/platform_helpers.S
index 8a07f8f..a5d26c0 100644
--- a/plat/common/aarch64/platform_helpers.S
+++ b/plat/common/aarch64/platform_helpers.S
@@ -22,6 +22,7 @@
 
 	.weak	plat_handle_uncontainable_ea
 	.weak	plat_handle_double_fault
+	.weak	plat_handle_el3_ea
 
 #if !ENABLE_PLAT_COMPAT
 	.globl	platform_get_core_pos
@@ -212,3 +213,11 @@
 func plat_handle_double_fault
 	b	report_unhandled_exception
 endfunc plat_handle_double_fault
+
+	/* -----------------------------------------------------
+	 * Platform handler for EL3 External Abort.
+	 * -----------------------------------------------------
+	 */
+func plat_handle_el3_ea
+	b	report_unhandled_exception
+endfunc plat_handle_el3_ea