Merge changes from topic "panic_cleanup" into integration

* changes:
  refactor(bl31): use elx_panic for sysreg_handler64
  refactor(aarch64): rename do_panic and el3_panic
  refactor(aarch64): remove weak links to el3_panic
  refactor(aarch64): refactor usage of elx_panic
  refactor(aarch64): cleanup HANDLE_EA_EL3_FIRST_NS usage

11 files changed, 81 insertions, 85 deletions

diff --git a/bl31/aarch64/crash_reporting.S b/bl31/aarch64/crash_reporting.S
index d56b513b8..4cec1103e 100644
--- a/bl31/aarch64/crash_reporting.S
+++ b/bl31/aarch64/crash_reporting.S
@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2014-2020, ARM Limited and Contributors. All rights reserved.
+ * Copyright (c) 2014-2023, Arm Limited and Contributors. All rights reserved.
  *
  * SPDX-License-Identifier: BSD-3-Clause
  */
@@ -15,8 +15,8 @@
 
 	.globl	report_unhandled_exception
 	.globl	report_unhandled_interrupt
-	.globl	el3_panic
-	.globl	elx_panic
+	.globl	report_el3_panic
+	.globl	report_elx_panic
 
 #if CRASH_REPORTING
 
@@ -64,7 +64,7 @@ intr_excpt_msg:
 x30_msg:
 	.asciz "x30"
 excpt_msg_el:
-	.asciz "Unhandled Exception from EL"
+	.asciz "Unhandled Exception from lower EL.\n"
 
 	/*
 	 * Helper function to print from crash buf.
@@ -194,28 +194,20 @@ endfunc report_unhandled_interrupt
 	/* -----------------------------------------------------
 	 * This function allows to report a crash from the lower
 	 * exception level (if crash reporting is enabled) when
-	 * panic() is invoked from C Runtime.
+	 * lower_el_panic() is invoked from C Runtime.
 	 * It prints the CPU state via the crash console making
 	 * use of 'cpu_context' structure where general purpose
 	 * registers are saved and the crash buf.
 	 * This function will not return.
-	 *
- 	 * x0: Exception level
 	 * -----------------------------------------------------
 	 */
-func elx_panic
+func report_elx_panic
 	msr	spsel, #MODE_SP_ELX
-	mov	x8, x0
 
 	/* Print the crash message */
 	adr	x4, excpt_msg_el
 	bl	asm_print_str
 
-	/* Print exception level */
-	add	x0, x8, #'0'
-	bl	plat_crash_console_putc
-	bl	asm_print_newline
-
 	/* Report x0 - x29 values stored in 'gpregs_ctx' structure */
 	/* Store the ascii list pointer in x6 */
 	adr	x6, gp_regs
@@ -295,7 +287,7 @@ from_el1:
 	mrs	x2, sctlr_el1
 	mrs	x1, tcr_el1
 	b	test_pauth
-endfunc	elx_panic
+endfunc	report_elx_panic
 
 	/* -----------------------------------------------------
 	 * This function allows to report a crash (if crash
@@ -305,7 +297,7 @@ endfunc	elx_panic
 	 * will not return.
 	 * -----------------------------------------------------
 	 */
-func el3_panic
+func report_el3_panic
 	msr	spsel, #MODE_SP_ELX
 	prepare_crash_buf_save_x0_x1
 	adr	x0, panic_msg
@@ -463,7 +455,7 @@ print_el3_sys_regs:
 
 	/* Done reporting */
 	no_ret	plat_panic_handler
-endfunc el3_panic
+endfunc report_el3_panic
 
 #else	/* CRASH_REPORTING */
 func report_unhandled_exception
diff --git a/bl31/aarch64/ea_delegate.S b/bl31/aarch64/ea_delegate.S
index 83e4582bd..9419476ce 100644
--- a/bl31/aarch64/ea_delegate.S
+++ b/bl31/aarch64/ea_delegate.S
@@ -190,7 +190,7 @@ func delegate_async_ea
 	 */
 	ubfx	x2, x1, #ESR_EC_SHIFT, #ESR_EC_LENGTH
 	cmp	x2, EC_SERROR
-	b.ne	do_panic
+	b.ne	el3_panic
 	/*
 	 * Check for Implementation Defined Syndrome. If so, skip checking
 	 * Uncontainable error type from the syndrome as the format is unknown.
diff --git a/bl31/aarch64/runtime_exceptions.S b/bl31/aarch64/runtime_exceptions.S
index 4cbcddcfe..500e87b9a 100644
--- a/bl31/aarch64/runtime_exceptions.S
+++ b/bl31/aarch64/runtime_exceptions.S
@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2013-2022, ARM Limited and Contributors. All rights reserved.
+ * Copyright (c) 2013-2023, ARM Limited and Contributors. All rights reserved.
  *
  * SPDX-License-Identifier: BSD-3-Clause
  */
@@ -569,7 +569,7 @@ sysreg_handler64:
 	 */
 
 	tst	w0, w0
-	b.mi	do_panic	/* negative return value: panic */
+	b.mi	elx_panic	/* negative return value: panic */
 	b.eq	1f		/* zero: do not change ELR_EL3 */
 
 	/* advance the PC to continue after the instruction */
diff --git a/common/aarch32/debug.S b/common/aarch32/debug.S
index ae0bb7ac7..2937f56fd 100644
--- a/common/aarch32/debug.S
+++ b/common/aarch32/debug.S
@@ -12,7 +12,7 @@
 	.globl	asm_print_hex
 	.globl	asm_print_hex_bits
 	.globl	asm_assert
-	.globl	do_panic
+	.globl	el3_panic
 	.globl	report_exception
 	.globl	report_prefetch_abort
 	.globl	report_data_abort
@@ -159,14 +159,14 @@ asm_print_hex_bits:
 endfunc asm_print_hex
 
 	/***********************************************************
-	 * The common implementation of do_panic for all BL stages
+	 * The common implementation of el3_panic for all BL stages
 	 ***********************************************************/
 
 .section .rodata.panic_str, "aS"
 	panic_msg: .asciz "PANIC at PC : 0x"
 	panic_end: .asciz "\r\n"
 
-func do_panic
+func el3_panic
 	/* Have LR copy point to PC at the time of panic */
 	sub	r6, lr, #4
 
@@ -194,7 +194,7 @@ func do_panic
 _panic_handler:
 	mov	lr, r6
 	b	plat_panic_handler
-endfunc do_panic
+endfunc el3_panic
 
 	/***********************************************************
 	 * This function is called from the vector table for
diff --git a/common/aarch64/debug.S b/common/aarch64/debug.S
index 742e022d5..8768a1f74 100644
--- a/common/aarch64/debug.S
+++ b/common/aarch64/debug.S
@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2014-2020, ARM Limited and Contributors. All rights reserved.
+ * Copyright (c) 2014-2023 Arm Limited and Contributors. All rights reserved.
  *
  * SPDX-License-Identifier: BSD-3-Clause
  */
@@ -13,7 +13,8 @@
 	.globl	asm_print_hex_bits
 	.globl	asm_print_newline
 	.globl	asm_assert
-	.globl	do_panic
+	.globl	el3_panic
+	.globl	elx_panic
 
 /* Since the max decimal input number is 65536 */
 #define MAX_DEC_DIVISOR		10000
@@ -145,54 +146,33 @@ func asm_print_newline
 endfunc asm_print_newline
 
 	/***********************************************************
-	 * The common implementation of do_panic for all BL stages
+	 * The common implementation of el3_panic for all BL stages
 	 ***********************************************************/
 
 .section .rodata.panic_str, "aS"
 	panic_msg: .asciz "PANIC at PC : 0x"
 
+func elx_panic
+#if CRASH_REPORTING && defined(IMAGE_BL31)
+	b	report_elx_panic
+#endif /* CRASH_REPORTING && IMAGE_BL31 */
+
+	b	panic_common
+endfunc elx_panic
+
 /* ---------------------------------------------------------------------------
- * do_panic assumes that it is invoked from a C Runtime Environment ie a
+ * el3_panic assumes that it is invoked from a C Runtime Environment ie a
  * valid stack exists. This call will not return.
  * Clobber list : if CRASH_REPORTING is not enabled then x30, x0 - x6
  * ---------------------------------------------------------------------------
  */
 
-/* This is for the non el3 BL stages to compile through */
-	.weak el3_panic
-	.weak elx_panic
-
-func do_panic
-#if CRASH_REPORTING
-	str	x0, [sp, #-0x10]!
-	mrs	x0, currentel
-	ubfx	x0, x0, #MODE_EL_SHIFT, #MODE_EL_WIDTH
-	cmp	x0, #MODE_EL3
-#if !HANDLE_EA_EL3_FIRST_NS
-	ldr	x0, [sp], #0x10
-	b.eq	el3_panic
-#else
-	b.ne	to_panic_common
-
-	/* Check EL the exception taken from */
-	mrs	x0, spsr_el3
-	ubfx	x0, x0, #SPSR_EL_SHIFT, #SPSR_EL_WIDTH
-	cmp	x0, #MODE_EL3
-	b.ne	elx_panic
-	ldr	x0, [sp], #0x10
-	b	el3_panic
-
-to_panic_common:
-	ldr	x0, [sp], #0x10
-#endif /* HANDLE_EA_EL3_FIRST_NS */
-#endif /* CRASH_REPORTING */
+func el3_panic
+#if CRASH_REPORTING && defined(IMAGE_BL31)
+	b	report_el3_panic
+#endif /* CRASH_REPORTING && IMAGE_BL31 */
 
 panic_common:
-/*
- * el3_panic will be redefined by the BL31
- * crash reporting mechanism (if enabled)
- */
-el3_panic:
 	mov	x6, x30
 	bl	plat_crash_console_init
 
@@ -218,4 +198,5 @@ _panic_handler:
 	 * called, not the address of the call from el3_panic. */
 	mov	x30, x6
 	b	plat_panic_handler
-endfunc do_panic
+
+endfunc el3_panic
diff --git a/docs/getting_started/porting-guide.rst b/docs/getting_started/porting-guide.rst
index ec0a4689c..0e4d1e31c 100644
--- a/docs/getting_started/porting-guide.rst
+++ b/docs/getting_started/porting-guide.rst
@@ -3204,9 +3204,20 @@ as Group 0 secure interrupt, Group 1 secure interrupt or Group 1 NS interrupt.
 
 Common helper functions
 -----------------------
+Function : elx_panic()
+~~~~~~~~~~~~~~~~~~~~~~
 
-Function : do_panic()
-~~~~~~~~~~~~~~~~~~~~~
+::
+
+    Argument : void
+    Return   : void
+
+This API is called from assembly files when reporting a critical failure
+that has occured in lower EL and is been trapped in EL3. This call
+**must not** return.
+
+Function : el3_panic()
+~~~~~~~~~~~~~~~~~~~~~~
 
 ::
 
@@ -3214,9 +3225,8 @@ Function : do_panic()
     Return   : void
 
 This API is called from assembly files when encountering a critical failure that
-cannot be recovered from. It also invokes elx_panic() which allows to report a
-crash from lower exception level. This function assumes that it is invoked from
-a C runtime environment i.e. valid stack exists. This call **must not** return.
+cannot be recovered from. This function assumes that it is invoked from a C
+runtime environment i.e. valid stack exists. This call **must not** return.
 
 Function : panic()
 ~~~~~~~~~~~~~~~~~~
@@ -3228,7 +3238,7 @@ Function : panic()
 
 This API called from C files when encountering a critical failure that cannot
 be recovered from. This function in turn prints backtrace (if enabled) and calls
-do_panic(). This call **must not** return.
+el3_panic(). This call **must not** return.
 
 Crash Reporting mechanism (in BL31)
 -----------------------------------
diff --git a/include/arch/aarch64/el3_common_macros.S b/include/arch/aarch64/el3_common_macros.S
index 40ff05668..7bd927de3 100644
--- a/include/arch/aarch64/el3_common_macros.S
+++ b/include/arch/aarch64/el3_common_macros.S
@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2015-2022, Arm Limited and Contributors. All rights reserved.
+ * Copyright (c) 2015-2023 Arm Limited and Contributors. All rights reserved.
  *
  * SPDX-License-Identifier: BSD-3-Clause
  */
diff --git a/include/common/debug.h b/include/common/debug.h
index af47999c3..5ea541da0 100644
--- a/include/common/debug.h
+++ b/include/common/debug.h
@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2013-2020, ARM Limited and Contributors. All rights reserved.
+ * Copyright (c) 2013-2023, Arm Limited and Contributors. All rights reserved.
  *
  * SPDX-License-Identifier: BSD-3-Clause
  */
@@ -99,15 +99,31 @@ void backtrace(const char *cookie);
 #define backtrace(x)
 #endif
 
-void __dead2 do_panic(void);
+void __dead2 el3_panic(void);
+void __dead2 elx_panic(void);
 
 #define panic()				\
 	do {				\
 		backtrace(__func__);	\
 		console_flush();	\
-		do_panic();		\
+		el3_panic();		\
 	} while (false)
 
+#if CRASH_REPORTING
+/* --------------------------------------------------------------------
+ * do_lower_el_panic assumes it's called due to a panic from a lower EL
+ * This call will not return.
+ * --------------------------------------------------------------------
+ */
+#define	lower_el_panic()		\
+	do {				\
+		console_flush();	\
+		elx_panic();		\
+	} while (false)
+#else
+#define	lower_el_panic()
+#endif
+
 /* Function called when stack protection check code detects a corrupted stack */
 void __dead2 __stack_chk_fail(void);
 
diff --git a/plat/arm/board/fvp_r/fvp_r_debug.S b/plat/arm/board/fvp_r/fvp_r_debug.S
index 88f0a29a0..cc5ffc074 100644
--- a/plat/arm/board/fvp_r/fvp_r_debug.S
+++ b/plat/arm/board/fvp_r/fvp_r_debug.S
@@ -11,7 +11,7 @@
 	.globl el2_panic
 
 	/***********************************************************
-	 * The common implementation of do_panic for all BL stages
+	 * The common implementation of el3_panic for all BL stages
 	 ***********************************************************/
 
 .section .rodata.panic_str, "aS"
diff --git a/plat/common/aarch64/plat_common.c b/plat/common/aarch64/plat_common.c
index 8ce1d6c76..042916a7d 100644
--- a/plat/common/aarch64/plat_common.c
+++ b/plat/common/aarch64/plat_common.c
@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2014-2022, ARM Limited and Contributors. All rights reserved.
+ * Copyright (c) 2014-2023, Arm Limited and Contributors. All rights reserved.
  *
  * SPDX-License-Identifier: BSD-3-Clause
  */
@@ -77,7 +77,7 @@ const char *get_el_str(unsigned int el)
 	return "EL1";
 }
 
-/* RAS functions common to AArch64 ARM platforms */
+/* Handler for External Aborts from lower EL including RAS errors */
 void plat_default_ea_handler(unsigned int ea_reason, uint64_t syndrome, void *cookie,
 		void *handle, uint64_t flags)
 {
@@ -93,12 +93,9 @@ void plat_default_ea_handler(unsigned int ea_reason, uint64_t syndrome, void *co
 	ERROR("Unhandled External Abort received on 0x%lx from %s\n",
 		read_mpidr_el1(), get_el_str(level));
 	ERROR("exception reason=%u syndrome=0x%" PRIx64 "\n", ea_reason, syndrome);
-#if HANDLE_EA_EL3_FIRST_NS
-	/* Skip backtrace for lower EL */
-	if (level != MODE_EL3) {
-		console_flush();
-		do_panic();
-	}
-#endif
-	panic();
+
+	/* We reached here due to a panic from a lower EL and assuming this is the default
+	 * platform registered handler that we could call on a lower EL panic.
+	 */
+	lower_el_panic();
 }
diff --git a/plat/renesas/common/aarch64/plat_helpers.S b/plat/renesas/common/aarch64/plat_helpers.S
index 21c3bedaf..a7fdfa071 100644
--- a/plat/renesas/common/aarch64/plat_helpers.S
+++ b/plat/renesas/common/aarch64/plat_helpers.S
@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2013-2020, ARM Limited and Contributors. All rights reserved.
+ * Copyright (c) 2013-2023, Arm Limited and Contributors. All rights reserved.
  * Copyright (c) 2015-2021, Renesas Electronics Corporation. All rights reserved.
  *
  * SPDX-License-Identifier: BSD-3-Clause
@@ -126,7 +126,7 @@ warm_reset:
 exit:
 	ret	x9
 _panic:
-	b	do_panic
+	b	el3_panic
 #endif
 
 endfunc plat_get_my_entrypoint