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ipxe/src/core/iobuf.c
Michael Brown 8406115834 [build] Rename gPXE to iPXE
Access to the gpxe.org and etherboot.org domains and associated
resources has been revoked by the registrant of the domain.  Work
around this problem by renaming project from gPXE to iPXE, and
updating URLs to match.

Also update README, LOG and COPYRIGHTS to remove obsolete information.

Signed-off-by: Michael Brown <mcb30@ipxe.org>
2010-04-19 23:43:39 +01:00

97 lines
2.4 KiB
C

/*
* Copyright (C) 2006 Michael Brown <mbrown@fensystems.co.uk>.
*
* This program is free software; you can redistribute it and/or
* modify it under the terms of the GNU General Public License as
* published by the Free Software Foundation; either version 2 of the
* License, or any later version.
*
* This program is distributed in the hope that it will be useful, but
* WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software
* Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
*/
FILE_LICENCE ( GPL2_OR_LATER );
#include <stdint.h>
#include <errno.h>
#include <ipxe/malloc.h>
#include <ipxe/iobuf.h>
/** @file
*
* I/O buffers
*
*/
/**
* Allocate I/O buffer
*
* @v len Required length of buffer
* @ret iobuf I/O buffer, or NULL if none available
*
* The I/O buffer will be physically aligned to a multiple of
* @c IOBUF_SIZE.
*/
struct io_buffer * alloc_iob ( size_t len ) {
struct io_buffer *iobuf = NULL;
void *data;
/* Pad to minimum length */
if ( len < IOB_ZLEN )
len = IOB_ZLEN;
/* Align buffer length */
len = ( len + __alignof__( *iobuf ) - 1 ) &
~( __alignof__( *iobuf ) - 1 );
/* Allocate memory for buffer plus descriptor */
data = malloc_dma ( len + sizeof ( *iobuf ), IOB_ALIGN );
if ( ! data )
return NULL;
iobuf = ( struct io_buffer * ) ( data + len );
iobuf->head = iobuf->data = iobuf->tail = data;
iobuf->end = iobuf;
return iobuf;
}
/**
* Free I/O buffer
*
* @v iobuf I/O buffer
*/
void free_iob ( struct io_buffer *iobuf ) {
if ( iobuf ) {
assert ( iobuf->head <= iobuf->data );
assert ( iobuf->data <= iobuf->tail );
assert ( iobuf->tail <= iobuf->end );
free_dma ( iobuf->head,
( iobuf->end - iobuf->head ) + sizeof ( *iobuf ) );
}
}
/**
* Ensure I/O buffer has sufficient headroom
*
* @v iobuf I/O buffer
* @v len Required headroom
*
* This function currently only checks for the required headroom; it
* does not reallocate the I/O buffer if required. If we ever have a
* code path that requires this functionality, it's a fairly trivial
* change to make.
*/
int iob_ensure_headroom ( struct io_buffer *iobuf, size_t len ) {
if ( iob_headroom ( iobuf ) >= len )
return 0;
return -ENOBUFS;
}