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/*
* JFFS2 -- Journalling Flash File System, Version 2.
*
* Copyright (C) 2001 Red Hat, Inc.
*
* Created by David Woodhouse <dwmw2@cambridge.redhat.com>
*
* The original JFFS, from which the design for JFFS2 was derived,
* was designed and implemented by Axis Communications AB.
*
* The contents of this file are subject to the Red Hat eCos Public
* License Version 1.1 (the "Licence"); you may not use this file
* except in compliance with the Licence. You may obtain a copy of
* the Licence at http://www.redhat.com/
*
* Software distributed under the Licence is distributed on an "AS IS"
* basis, WITHOUT WARRANTY OF ANY KIND, either express or implied.
* See the Licence for the specific language governing rights and
* limitations under the Licence.
*
* The Original Code is JFFS2 - Journalling Flash File System, version 2
*
* Alternatively, the contents of this file may be used under the
* terms of the GNU General Public License version 2 (the "GPL"), in
* which case the provisions of the GPL are applicable instead of the
* above. If you wish to allow the use of your version of this file
* only under the terms of the GPL and not to allow others to use your
* version of this file under the RHEPL, indicate your decision by
* deleting the provisions above and replace them with the notice and
* other provisions required by the GPL. If you do not delete the
* provisions above, a recipient may use your version of this file
* under either the RHEPL or the GPL.
*
* $Id: pushpull.c,v 1.7 2001/09/23 10:04:15 rmk Exp $
*
*/
#include <linux/string.h>
#include "pushpull.h"
#include <linux/errno.h>
void init_pushpull(struct pushpull *pp, char *buf, unsigned buflen, unsigned ofs, unsigned reserve)
{
pp->buf = buf;
pp->buflen = buflen;
pp->ofs = ofs;
pp->reserve = reserve;
}
int pushbit(struct pushpull *pp, int bit, int use_reserved)
{
if (pp->ofs >= pp->buflen - (use_reserved?0:pp->reserve)) {
return -ENOSPC;
}
if (bit) {
pp->buf[pp->ofs >> 3] |= (1<<(7-(pp->ofs &7)));
}
else {
pp->buf[pp->ofs >> 3] &= ~(1<<(7-(pp->ofs &7)));
}
pp->ofs++;
return 0;
}
int pushedbits(struct pushpull *pp)
{
return pp->ofs;
}
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