/*
 * FreeRTOS+TCP V3.1.0
 * Copyright (C) 2022 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.
 *
 * 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 );
    }
}
