Add Cortex-A53 port with system register interface for CPU interface access (#357)

The difference between this port and portable/GCC/ARM_CA53_64_BIT is
that this port uses System Register interface to access CPU interface
while the other one uses Memory-mapped interface.

Signed-off-by: Gaurav Aggarwal 
Co-authored-by: Cobus van Eeden <35851496+cobusve@users.noreply.github.com>

portable/GCC/ARM_CA53_64_BIT_SRE/portmacro.h

@@ -0,0 +1,197 @@
+/*
+ * FreeRTOS Kernel <DEVELOPMENT BRANCH>
+ * Copyright (C) 2021 Amazon.com, Inc. or its affiliates.  All Rights Reserved.
+ *
+ * SPDX-License-Identifier: MIT
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy of
+ * this software and associated documentation files (the "Software"), to deal in
+ * the Software without restriction, including without limitation the rights to
+ * use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of
+ * the Software, and to permit persons to whom the Software is furnished to do so,
+ * subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in all
+ * copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS
+ * FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR
+ * COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER
+ * IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
+ * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
+ *
+ * https://www.FreeRTOS.org
+ * https://github.com/FreeRTOS
+ *
+ */
+
+#ifndef PORTMACRO_H
+#define PORTMACRO_H
+
+#ifdef __cplusplus
+	extern "C" {
+#endif
+
+/*-----------------------------------------------------------
+ * Port specific definitions.
+ *
+ * The settings in this file configure FreeRTOS correctly for the given hardware
+ * and compiler.
+ *
+ * These settings should not be altered.
+ *-----------------------------------------------------------
+ */
+
+/* Type definitions. */
+#define portCHAR		char
+#define portFLOAT		float
+#define portDOUBLE		double
+#define portLONG		long
+#define portSHORT		short
+#define portSTACK_TYPE	size_t
+#define portBASE_TYPE	long
+
+typedef portSTACK_TYPE StackType_t;
+typedef portBASE_TYPE BaseType_t;
+typedef uint64_t UBaseType_t;
+
+typedef uint64_t TickType_t;
+#define portMAX_DELAY ( ( TickType_t ) 0xffffffffffffffff )
+
+/* 32-bit tick type on a 32-bit architecture, so reads of the tick count do
+not need to be guarded with a critical section. */
+#define portTICK_TYPE_IS_ATOMIC 1
+
+/*-----------------------------------------------------------*/
+
+/* Hardware specifics. */
+#define portSTACK_GROWTH			( -1 )
+#define portTICK_PERIOD_MS			( ( TickType_t ) 1000 / configTICK_RATE_HZ )
+#define portBYTE_ALIGNMENT			16
+#define portPOINTER_SIZE_TYPE 		uint64_t
+
+/*-----------------------------------------------------------*/
+
+/* Task utilities. */
+
+/* Called at the end of an ISR that can cause a context switch. */
+#define portEND_SWITCHING_ISR( xSwitchRequired )\
+{												\
+extern uint64_t ullPortYieldRequired;			\
+												\
+	if( xSwitchRequired != pdFALSE )			\
+	{											\
+		ullPortYieldRequired = pdTRUE;			\
+	}											\
+}
+
+#define portYIELD_FROM_ISR( x ) portEND_SWITCHING_ISR( x )
+#if defined( GUEST )
+	#define portYIELD() __asm volatile ( "SVC 0" ::: "memory" )
+#else
+	#define portYIELD() __asm volatile ( "SMC 0" ::: "memory" )
+#endif
+/*-----------------------------------------------------------
+ * Critical section control
+ *----------------------------------------------------------*/
+
+extern void vPortEnterCritical( void );
+extern void vPortExitCritical( void );
+extern UBaseType_t uxPortSetInterruptMask( void );
+extern void vPortClearInterruptMask( UBaseType_t uxNewMaskValue );
+extern void vPortInstallFreeRTOSVectorTable( void );
+
+#define portDISABLE_INTERRUPTS()									\
+	__asm volatile ( "MSR DAIFSET, #2" ::: "memory" );				\
+	__asm volatile ( "DSB SY" );									\
+	__asm volatile ( "ISB SY" );
+
+#define portENABLE_INTERRUPTS()										\
+	__asm volatile ( "MSR DAIFCLR, #2" ::: "memory" );				\
+	__asm volatile ( "DSB SY" );									\
+	__asm volatile ( "ISB SY" );
+
+
+/* These macros do not globally disable/enable interrupts.  They do mask off
+interrupts that have a priority below configMAX_API_CALL_INTERRUPT_PRIORITY. */
+#define portENTER_CRITICAL()		vPortEnterCritical();
+#define portEXIT_CRITICAL()			vPortExitCritical();
+#define portSET_INTERRUPT_MASK_FROM_ISR()		uxPortSetInterruptMask()
+#define portCLEAR_INTERRUPT_MASK_FROM_ISR(x)	vPortClearInterruptMask(x)
+
+/*-----------------------------------------------------------*/
+
+/* Task function macros as described on the FreeRTOS.org WEB site.  These are
+not required for this port but included in case common demo code that uses these
+macros is used. */
+#define portTASK_FUNCTION_PROTO( vFunction, pvParameters )	void vFunction( void *pvParameters )
+#define portTASK_FUNCTION( vFunction, pvParameters )	void vFunction( void *pvParameters )
+
+/* Prototype of the FreeRTOS tick handler.  This must be installed as the
+handler for whichever peripheral is used to generate the RTOS tick. */
+void FreeRTOS_Tick_Handler( void );
+
+/* Any task that uses the floating point unit MUST call vPortTaskUsesFPU()
+before any floating point instructions are executed. */
+void vPortTaskUsesFPU( void );
+#define portTASK_USES_FLOATING_POINT() vPortTaskUsesFPU()
+
+#define portLOWEST_INTERRUPT_PRIORITY ( ( ( uint32_t ) configUNIQUE_INTERRUPT_PRIORITIES ) - 1UL )
+#define portLOWEST_USABLE_INTERRUPT_PRIORITY ( portLOWEST_INTERRUPT_PRIORITY - 1UL )
+
+/* Architecture specific optimisations. */
+#ifndef configUSE_PORT_OPTIMISED_TASK_SELECTION
+	#define configUSE_PORT_OPTIMISED_TASK_SELECTION 1
+#endif
+
+#if configUSE_PORT_OPTIMISED_TASK_SELECTION == 1
+
+	/* Store/clear the ready priorities in a bit map. */
+	#define portRECORD_READY_PRIORITY( uxPriority, uxReadyPriorities ) ( uxReadyPriorities ) |= ( 1UL << ( uxPriority ) )
+	#define portRESET_READY_PRIORITY( uxPriority, uxReadyPriorities ) ( uxReadyPriorities ) &= ~( 1UL << ( uxPriority ) )
+
+	/*-----------------------------------------------------------*/
+
+	#define portGET_HIGHEST_PRIORITY( uxTopPriority, uxReadyPriorities ) uxTopPriority = ( 31 - __builtin_clz( uxReadyPriorities ) )
+
+#endif /* configUSE_PORT_OPTIMISED_TASK_SELECTION */
+
+#ifdef configASSERT
+	void vPortValidateInterruptPriority( void );
+	#define portASSERT_IF_INTERRUPT_PRIORITY_INVALID() 	vPortValidateInterruptPriority()
+#endif /* configASSERT */
+
+#define portNOP() __asm volatile( "NOP" )
+#define portINLINE __inline
+
+#ifdef __cplusplus
+	} /* extern C */
+#endif
+
+
+/* The number of bits to shift for an interrupt priority is dependent on the
+number of bits implemented by the interrupt controller. */
+#if configUNIQUE_INTERRUPT_PRIORITIES == 16
+	#define portPRIORITY_SHIFT 4
+	#define portMAX_BINARY_POINT_VALUE	3
+#elif configUNIQUE_INTERRUPT_PRIORITIES == 32
+	#define portPRIORITY_SHIFT 3
+	#define portMAX_BINARY_POINT_VALUE	2
+#elif configUNIQUE_INTERRUPT_PRIORITIES == 64
+	#define portPRIORITY_SHIFT 2
+	#define portMAX_BINARY_POINT_VALUE	1
+#elif configUNIQUE_INTERRUPT_PRIORITIES == 128
+	#define portPRIORITY_SHIFT 1
+	#define portMAX_BINARY_POINT_VALUE	0
+#elif configUNIQUE_INTERRUPT_PRIORITIES == 256
+	#define portPRIORITY_SHIFT 0
+	#define portMAX_BINARY_POINT_VALUE	0
+#else
+	#error Invalid configUNIQUE_INTERRUPT_PRIORITIES setting.  configUNIQUE_INTERRUPT_PRIORITIES must be set to the number of unique priorities implemented by the target hardware
+#endif
+
+#define portMEMORY_BARRIER() __asm volatile( "" ::: "memory" )
+
+#endif /* PORTMACRO_H */
+