/*
 * FreeRTOS V202002.00
 * Copyright (C) 2020 Amazon.com, Inc. or its affiliates.  All Rights Reserved.
 *
 * 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.
 *
 * http://aws.amazon.com/freertos
 * http://www.FreeRTOS.org
 */

/*
 * uncached_memory.c
 *
 * This module will declare 1 MB of memory and switch off the caching for it.
 *
 * pucGetUncachedMemory( ulSize ) returns a trunc of this memory with a length
 * rounded up to a multiple of 4 KB.
 *
 * ucIsCachedMemory( pucBuffer ) returns non-zero if a given pointer is NOT
 * within the range of the 1 MB non-cached memory.
 *
 */

/*
 * After "_end", 1 MB of uncached memory will be allocated for DMA transfers.
 * Both the DMA descriptors as well as all EMAC TX-buffers will be allocated in
 * uncached memory.
 */

/* Standard includes. */
#include <stdint.h>
#include <stdio.h>
#include <stdlib.h>

/* FreeRTOS includes. */
#include "FreeRTOS.h"
#include "task.h"
#include "queue.h"

/* FreeRTOS+TCP includes. */
#include "FreeRTOS_IP.h"
#include "FreeRTOS_Sockets.h"
#include "FreeRTOS_IP_Private.h"

#include "Zynq/x_emacpsif.h"
#include "Zynq/x_topology.h"
#include "xstatus.h"

#include "xparameters.h"
#include "xparameters_ps.h"
#include "xil_exception.h"
#include "xil_mmu.h"

#include "uncached_memory.h"

/* Reserve 1 MB of memory. */
#define uncMEMORY_SIZE				0x100000uL

/* Make sure that each pointer has an alignment of 4 KB. */
#define uncALIGNMENT_SIZE			0x1000uL

#define DDR_MEMORY_END	(XPAR_PS7_DDR_0_S_AXI_HIGHADDR+1)

#define uncMEMORY_ATTRIBUTE			0x1C02

static void vInitialiseUncachedMemory( void );

static uint8_t *pucHeadOfMemory;
static uint32_t ulMemorySize;
static uint8_t *pucStartOfMemory = NULL;

/* The linker file defines some pseudo variables. '_end' is one of them.
It is located at the first free byte in RAM. */
extern u8 _end;

/*-----------------------------------------------------------*/

uint8_t ucIsCachedMemory( const uint8_t *pucBuffer )
{
uint8_t ucReturn;

	if( ( pucStartOfMemory != NULL ) &&
		( pucBuffer >= pucStartOfMemory ) &&
		( pucBuffer < ( pucStartOfMemory + uncMEMORY_SIZE ) ) )
	{
		ucReturn = pdFALSE;
	}
	else
	{
		ucReturn = pdTRUE;
	}

	return ucReturn;
}
/*-----------------------------------------------------------*/

uint8_t *pucGetUncachedMemory( uint32_t ulSize )
{
uint8_t *pucReturn;
uint32_t ulSkipSize;

	if( pucStartOfMemory == NULL )
	{
		vInitialiseUncachedMemory( );
	}
	if( ( pucStartOfMemory == NULL ) || ( ulSize > ulMemorySize ) )
	{
		pucReturn = NULL;
	}
	else
	{
		pucReturn = pucHeadOfMemory;
		/* Make sure that the next pointer return will have a good alignment. */
		ulSkipSize = ( ulSize + uncALIGNMENT_SIZE ) & ~( uncALIGNMENT_SIZE - 1uL );
		pucHeadOfMemory += ulSkipSize;
		ulMemorySize -= ulSkipSize;
	}

	return pucReturn;
}
/*-----------------------------------------------------------*/

static void vInitialiseUncachedMemory( )
{
	/* At the end of program's space... */
	pucStartOfMemory = ( uint8_t * ) &( _end );

	/* Align the start address to 1 MB boundary. */
	pucStartOfMemory = ( uint8_t * )( ( ( uint32_t )pucStartOfMemory + uncMEMORY_SIZE ) & ( ~( uncMEMORY_SIZE - 1 ) ) );

	if( ( ( u32 )pucStartOfMemory ) + uncMEMORY_SIZE > DDR_MEMORY_END )
	{
		FreeRTOS_printf( ( "vInitialiseUncachedMemory: Can not allocate uncached memory\n" ) );
	}
	else
	{
		/* Some objects want to be stored in uncached memory. Hence the 1 MB
		address range that starts after "_end" is made uncached by setting
		appropriate attributes in the translation table. */
		Xil_SetTlbAttributes( ( uint32_t ) pucStartOfMemory, uncMEMORY_ATTRIBUTE );

		/* For experiments in the SDIO driver, make the remaining uncached memory
		public */
		pucHeadOfMemory = pucStartOfMemory;
		ulMemorySize = uncMEMORY_SIZE;
		memset( pucStartOfMemory, '\0', uncMEMORY_SIZE );
	}
}
