/* | |
* FreeRTOS+UDP V1.0.4 | |
* Copyright (C) 2017 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://www.FreeRTOS.org | |
* http://aws.amazon.com/freertos | |
* | |
* 1 tab == 4 spaces! | |
*/ | |
/****************************************************************************** | |
* | |
* See the following web page for essential buffer allocation scheme usage and | |
* configuration details: | |
* http://www.FreeRTOS.org/FreeRTOS-Plus/FreeRTOS_Plus_UDP/Embedded_Ethernet_Buffer_Management.shtml | |
* | |
******************************************************************************/ | |
/* Standard includes. */ | |
#include <stdint.h> | |
/* FreeRTOS includes. */ | |
#include "FreeRTOS.h" | |
#include "task.h" | |
#include "semphr.h" | |
/* FreeRTOS+UDP includes. */ | |
#include "FreeRTOS_UDP_IP.h" | |
#include "FreeRTOS_IP_Private.h" | |
#include "NetworkInterface.h" | |
/* For an Ethernet interrupt to be able to obtain a network buffer there must | |
be at least this number of buffers available. */ | |
#define ipINTERRUPT_BUFFER_GET_THRESHOLD ( 3 ) | |
/* A list of free (available) xNetworkBufferDescriptor_t structures. */ | |
static xList xFreeBuffersList; | |
/* Declares the pool of xNetworkBufferDescriptor_t structures that are available to the | |
system. All the network buffers referenced from xFreeBuffersList exist in this | |
array. The array is not accessed directly except during initialisation, when | |
the xFreeBuffersList is filled (as all the buffers are free when the system is | |
booted). */ | |
static xNetworkBufferDescriptor_t xNetworkBuffers[ ipconfigNUM_NETWORK_BUFFERS ]; | |
/* The semaphore used to obtain network buffers. */ | |
static xSemaphoreHandle xNetworkBufferSemaphore = NULL; | |
/*-----------------------------------------------------------*/ | |
BaseType_t xNetworkBuffersInitialise( void ) | |
{ | |
BaseType_t xReturn, x; | |
/* Only initialise the buffers and their associated kernel objects if they | |
have not been initialised before. */ | |
if( xNetworkBufferSemaphore == NULL ) | |
{ | |
xNetworkBufferSemaphore = xSemaphoreCreateCounting( ipconfigNUM_NETWORK_BUFFERS, ipconfigNUM_NETWORK_BUFFERS ); | |
configASSERT( xNetworkBufferSemaphore ); | |
if( xNetworkBufferSemaphore != NULL ) | |
{ | |
vListInitialise( &xFreeBuffersList ); | |
/* Initialise all the network buffers. The buffer storage comes | |
from the network interface, and different hardware has different | |
requirements. */ | |
vNetworkInterfaceAllocateRAMToBuffers( xNetworkBuffers ); | |
for( x = 0; x < ipconfigNUM_NETWORK_BUFFERS; x++ ) | |
{ | |
/* Initialise and set the owner of the buffer list items. */ | |
vListInitialiseItem( &( xNetworkBuffers[ x ].xBufferListItem ) ); | |
listSET_LIST_ITEM_OWNER( &( xNetworkBuffers[ x ].xBufferListItem ), &xNetworkBuffers[ x ] ); | |
/* Currently, all buffers are available for use. */ | |
vListInsert( &xFreeBuffersList, &( xNetworkBuffers[ x ].xBufferListItem ) ); | |
} | |
} | |
} | |
if( xNetworkBufferSemaphore == NULL ) | |
{ | |
xReturn = pdFAIL; | |
} | |
else | |
{ | |
xReturn = pdPASS; | |
} | |
return xReturn; | |
} | |
/*-----------------------------------------------------------*/ | |
xNetworkBufferDescriptor_t *pxNetworkBufferGet( size_t xRequestedSizeBytes, TickType_t xBlockTimeTicks ) | |
{ | |
xNetworkBufferDescriptor_t *pxReturn = NULL; | |
/*_RB_ The current implementation only has a single size memory block, so | |
the requested size parameter is not used (yet). */ | |
( void ) xRequestedSizeBytes; | |
/* If there is a semaphore available, there is a network buffer available. */ | |
if( xSemaphoreTake( xNetworkBufferSemaphore, xBlockTimeTicks ) == pdPASS ) | |
{ | |
/* Protect the structure as it is accessed from tasks and interrupts. */ | |
taskENTER_CRITICAL(); | |
{ | |
pxReturn = ( xNetworkBufferDescriptor_t * ) listGET_OWNER_OF_HEAD_ENTRY( &xFreeBuffersList ); | |
uxListRemove( &( pxReturn->xBufferListItem ) ); | |
} | |
taskEXIT_CRITICAL(); | |
iptraceNETWORK_BUFFER_OBTAINED( pxReturn ); | |
} | |
else | |
{ | |
iptraceFAILED_TO_OBTAIN_NETWORK_BUFFER(); | |
} | |
return pxReturn; | |
} | |
/*-----------------------------------------------------------*/ | |
xNetworkBufferDescriptor_t *pxNetworkBufferGetFromISR( size_t xRequestedSizeBytes ) | |
{ | |
xNetworkBufferDescriptor_t *pxReturn = NULL; | |
UBaseType_t uxSavedInterruptStatus; | |
/*_RB_ The current implementation only has a single size memory block, so | |
the requested size parameter is not used (yet). */ | |
( void ) xRequestedSizeBytes; | |
/* If there is a semaphore available then there is a buffer available, but, | |
as this is called from an interrupt, only take a buffer if there are at | |
least ipINTERRUPT_BUFFER_GET_THRESHOLD buffers remaining. This prevents, | |
to a certain degree at least, a rapidly executing interrupt exhausting | |
buffer and in so doing preventing tasks from continuing. */ | |
if( uxQueueMessagesWaitingFromISR( ( xQueueHandle ) xNetworkBufferSemaphore ) > ipINTERRUPT_BUFFER_GET_THRESHOLD ) | |
{ | |
if( xSemaphoreTakeFromISR( xNetworkBufferSemaphore, NULL ) == pdPASS ) | |
{ | |
/* Protect the structure as it is accessed from tasks and interrupts. */ | |
uxSavedInterruptStatus = portSET_INTERRUPT_MASK_FROM_ISR(); | |
{ | |
pxReturn = ( xNetworkBufferDescriptor_t * ) listGET_OWNER_OF_HEAD_ENTRY( &xFreeBuffersList ); | |
uxListRemove( &( pxReturn->xBufferListItem ) ); | |
} | |
portCLEAR_INTERRUPT_MASK_FROM_ISR( uxSavedInterruptStatus ); | |
iptraceNETWORK_BUFFER_OBTAINED_FROM_ISR( pxReturn ); | |
} | |
} | |
if( pxReturn == NULL ) | |
{ | |
iptraceFAILED_TO_OBTAIN_NETWORK_BUFFER_FROM_ISR(); | |
} | |
return pxReturn; | |
} | |
/*-----------------------------------------------------------*/ | |
BaseType_t vNetworkBufferReleaseFromISR( xNetworkBufferDescriptor_t * const pxNetworkBuffer ) | |
{ | |
UBaseType_t uxSavedInterruptStatus; | |
BaseType_t xHigherPriorityTaskWoken = pdFALSE; | |
/* Ensure the buffer is returned to the list of free buffers before the | |
counting semaphore is 'given' to say a buffer is available. */ | |
uxSavedInterruptStatus = portSET_INTERRUPT_MASK_FROM_ISR(); | |
{ | |
vListInsertEnd( &xFreeBuffersList, &( pxNetworkBuffer->xBufferListItem ) ); | |
} | |
portCLEAR_INTERRUPT_MASK_FROM_ISR( uxSavedInterruptStatus ); | |
xSemaphoreGiveFromISR( xNetworkBufferSemaphore, &xHigherPriorityTaskWoken ); | |
iptraceNETWORK_BUFFER_RELEASED( pxNetworkBuffer ); | |
return xHigherPriorityTaskWoken; | |
} | |
/*-----------------------------------------------------------*/ | |
void vNetworkBufferRelease( xNetworkBufferDescriptor_t * const pxNetworkBuffer ) | |
{ | |
BaseType_t xListItemAlreadyInFreeList; | |
/* Ensure the buffer is returned to the list of free buffers before the | |
counting semaphore is 'given' to say a buffer is available. */ | |
taskENTER_CRITICAL(); | |
{ | |
xListItemAlreadyInFreeList = listIS_CONTAINED_WITHIN( &xFreeBuffersList, &( pxNetworkBuffer->xBufferListItem ) ); | |
if( xListItemAlreadyInFreeList == pdFALSE ) | |
{ | |
vListInsertEnd( &xFreeBuffersList, &( pxNetworkBuffer->xBufferListItem ) ); | |
} | |
configASSERT( xListItemAlreadyInFreeList == pdFALSE ); | |
} | |
taskEXIT_CRITICAL(); | |
xSemaphoreGive( xNetworkBufferSemaphore ); | |
iptraceNETWORK_BUFFER_RELEASED( pxNetworkBuffer ); | |
} | |
/*-----------------------------------------------------------*/ | |
#if( ipconfigINCLUDE_TEST_CODE == 1 ) | |
UBaseType_t uxGetNumberOfFreeNetworkBuffers( void ) | |
{ | |
return listCURRENT_LIST_LENGTH( &xFreeBuffersList ); | |
} | |
#endif /* ipconfigINCLUDE_TEST_CODE */ |