fix(bl31): pass the EA bit to 'delegate_sync_ea'

During a synchronous exception, the 'enter_lower_el_sync_ea' handler
tests the ESR_EL3 EA bit and calls 'report_unhandled_exception', if
it is not set.

EA = 0 and IFSC = SEA, seems to be a contradiction. EA provides further
classification of a synchronous abort. A synchronous abort is determined
by the IFSC value on an instruction fetch synchronous abort. As a result,
EA will never be set to 1 on an instruction fetch synchronous abort and
'report_unhandled_exception' should not be called.

This patch removes this behavior to allow the platform to handle the
exception.

Signed-off-by: Nicolas Benech <nbenech@nvidia.com>
Signed-off-by: Varun Wadekar <vwadekar@nvidia.com>
Change-Id: I3f004447ad4316d81649063e1ffb3ac644c83ede

bl31/aarch64/ea_delegate.S

@@ -1,5 +1,6 @@
 /*
  * Copyright (c) 2018-2022, ARM Limited and Contributors. All rights reserved.
+ * Copyright (c) 2022, NVIDIA Corporation. All rights reserved.
  *
  * SPDX-License-Identifier: BSD-3-Clause
  */
@@ -84,10 +85,6 @@ func enter_lower_el_sync_ea
 	b	2f
 
 1:
-	/* Test for EA bit in the instruction syndrome */
-	mrs	x30, esr_el3
-	tbz	x30, #ESR_ISS_EABORT_EA_BIT, 3f
-
 	/*
 	 * Save general purpose and ARMv8.3-PAuth registers (if enabled).
 	 * If Secure Cycle Counter is not disabled in MDCR_EL3 when
@@ -114,7 +111,6 @@ func enter_lower_el_sync_ea
 	ldp	x2, x3, [sp, #CTX_GPREGS_OFFSET + CTX_GPREG_X2]
 	ldp	x4, x5, [sp, #CTX_GPREGS_OFFSET + CTX_GPREG_X4]
 
-3:
 	/* Synchronous exceptions other than the above are assumed to be EA */
 	ldr	x30, [sp, #CTX_GPREGS_OFFSET + CTX_GPREG_LR]
 	no_ret	report_unhandled_exception