You can not select more than 25 topics
Topics must start with a letter or number, can include dashes ('-') and can be up to 35 characters long.
72 lines
1.3 KiB
72 lines
1.3 KiB
/*
|
|
* JFFS2 -- Journalling Flash File System, Version 2.
|
|
*
|
|
* Copyright (C) 2001, 2002 Red Hat, Inc.
|
|
*
|
|
* Created by David Woodhouse <dwmw2@infradead.org>
|
|
*
|
|
* For licensing information, see the file 'LICENCE' in this directory.
|
|
*
|
|
* $Id: pushpull.h,v 1.10 2004/11/16 20:36:11 dwmw2 Exp $
|
|
*
|
|
*/
|
|
|
|
#ifndef __PUSHPULL_H__
|
|
#define __PUSHPULL_H__
|
|
|
|
#include <linux/errno.h>
|
|
|
|
struct pushpull {
|
|
unsigned char *buf;
|
|
unsigned int buflen;
|
|
unsigned int ofs;
|
|
unsigned int reserve;
|
|
};
|
|
|
|
|
|
static inline 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;
|
|
}
|
|
|
|
static inline 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;
|
|
}
|
|
|
|
static inline int pushedbits(struct pushpull *pp)
|
|
{
|
|
return pp->ofs;
|
|
}
|
|
|
|
static inline int pullbit(struct pushpull *pp)
|
|
{
|
|
int bit;
|
|
|
|
bit = (pp->buf[pp->ofs >> 3] >> (7-(pp->ofs & 7))) & 1;
|
|
|
|
pp->ofs++;
|
|
return bit;
|
|
}
|
|
|
|
static inline int pulledbits(struct pushpull *pp)
|
|
{
|
|
return pp->ofs;
|
|
}
|
|
|
|
#endif /* __PUSHPULL_H__ */
|
|
|