e2fsprogs/lib/ext2fs/bitops.c

96 lines
2.2 KiB
C

/*
* bitops.c --- Bitmap frobbing code. See bitops.h for the inlined
* routines.
*
* Copyright (C) 1993, 1994 Theodore Ts'o. This file may be
* redistributed under the terms of the GNU Public License.
*
* Taken from <asm/bitops.h>, Copyright 1992, Linus Torvalds.
*/
#include <stdio.h>
#include <sys/types.h>
#include <linux/fs.h>
#include <linux/ext2_fs.h>
#include "ext2fs.h"
#if (!defined(__i386__) && !defined(__i486__) && !defined(__i586__))
/*
* For the benefit of those who are trying to port Linux to another
* architecture, here are some C-language equivalents. You should
* recode these in the native assmebly language, if at all possible.
* To guarantee atomicity, these routines call cli() and sti() to
* disable interrupts while they operate. (You have to provide inline
* routines to cli() and sti().)
*
* Also note, these routines assume that you have 32 bit integers.
* You will have to change this if you are trying to port Linux to the
* Alpha architecture or to a Cray. :-)
*
* C language equivalents written by Theodore Ts'o, 9/26/92
*/
int set_bit(int nr,void * addr)
{
int mask, retval;
int *ADDR = (int *) addr;
ADDR += nr >> 5;
mask = 1 << (nr & 0x1f);
cli();
retval = (mask & *ADDR) != 0;
*ADDR |= mask;
sti();
return retval;
}
int clear_bit(int nr, void * addr)
{
int mask, retval;
int *ADDR = (int *) addr;
ADDR += nr >> 5;
mask = 1 << (nr & 0x1f);
cli();
retval = (mask & *ADDR) != 0;
*ADDR &= ~mask;
sti();
return retval;
}
int test_bit(int nr, const void * addr)
{
int mask;
const int *ADDR = (const int *) addr;
ADDR += nr >> 5;
mask = 1 << (nr & 0x1f);
return ((mask & *ADDR) != 0);
}
#endif /* !i386 */
/*
* These are routines print warning messages; they are called by
* inline routines.
*/
const char *ext2fs_block_string = "block";
const char *ext2fs_inode_string = "inode";
const char *ext2fs_mark_string = "mark";
const char *ext2fs_unmark_string = "unmark";
const char *ext2fs_test_string = "test";
void ext2fs_warn_bitmap(ext2_filsys fs, const char *op, const char *type,
int arg)
{
char func[80];
sprintf(func, "ext2fs_%s_%s_bitmap", op, type);
com_err(func, 0, "INTERNAL ERROR: illegal %s #%d for %s",
type, arg, fs->device_name);
}