74 lines
1.9 KiB
C
74 lines
1.9 KiB
C
/*
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* Copyright (C) 2006 Michael Brown <mbrown@fensystems.co.uk>.
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*
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* This program is free software; you can redistribute it and/or
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* modify it under the terms of the GNU General Public License as
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* published by the Free Software Foundation; either version 2 of the
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* License, or any later version.
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*
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* This program is distributed in the hope that it will be useful, but
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* WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
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* General Public License for more details.
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*
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* You should have received a copy of the GNU General Public License
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* along with this program; if not, write to the Free Software
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* Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
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*/
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#include <stdint.h>
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#include <malloc.h>
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#include <gpxe/pkbuff.h>
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/** @file
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*
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* Packet buffers
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*
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*/
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/**
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* Allocate packet buffer
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*
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* @v len Required length of buffer
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* @ret pkb Packet buffer, or NULL if none available
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*
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* The packet buffer will be physically aligned to a multiple of
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* @c PKBUFF_SIZE.
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*/
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struct pk_buff * alloc_pkb ( size_t len ) {
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struct pk_buff *pkb = NULL;
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void *data;
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/* Pad to minimum length */
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if ( len < PKB_ZLEN )
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len = PKB_ZLEN;
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/* Align buffer length */
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len = ( len + __alignof__( *pkb ) - 1 ) & ~( __alignof__( *pkb ) - 1 );
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/* Allocate memory for buffer plus descriptor */
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data = malloc_dma ( len + sizeof ( *pkb ), PKBUFF_ALIGN );
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if ( ! data )
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return NULL;
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pkb = ( struct pk_buff * ) ( data + len );
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pkb->head = pkb->data = pkb->tail = data;
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pkb->end = pkb;
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return pkb;
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}
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/**
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* Free packet buffer
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*
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* @v pkb Packet buffer
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*/
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void free_pkb ( struct pk_buff *pkb ) {
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if ( pkb ) {
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assert ( pkb->head <= pkb->data );
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assert ( pkb->data <= pkb->tail );
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assert ( pkb->tail <= pkb->end );
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free_dma ( pkb->head,
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( pkb->end - pkb->head ) + sizeof ( *pkb ) );
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}
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}
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