mirror of
https://github.com/torvalds/linux.git
synced 2024-11-16 00:52:01 +00:00
3821af2fe1
Signed-off-by: Stephen Hemminger <shemminger@osdl.org> Signed-off-by: David S. Miller <davem@davemloft.net>
83 lines
1.8 KiB
C
83 lines
1.8 KiB
C
#ifndef _ASM_GENERIC_BITOPS_H_
|
|
#define _ASM_GENERIC_BITOPS_H_
|
|
|
|
/*
|
|
* 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 assembly 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 longs.
|
|
* 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
|
|
*/
|
|
|
|
extern __inline__ int set_bit(int nr,long * addr)
|
|
{
|
|
int mask, retval;
|
|
|
|
addr += nr >> 5;
|
|
mask = 1 << (nr & 0x1f);
|
|
cli();
|
|
retval = (mask & *addr) != 0;
|
|
*addr |= mask;
|
|
sti();
|
|
return retval;
|
|
}
|
|
|
|
extern __inline__ int clear_bit(int nr, long * addr)
|
|
{
|
|
int mask, retval;
|
|
|
|
addr += nr >> 5;
|
|
mask = 1 << (nr & 0x1f);
|
|
cli();
|
|
retval = (mask & *addr) != 0;
|
|
*addr &= ~mask;
|
|
sti();
|
|
return retval;
|
|
}
|
|
|
|
extern __inline__ int test_bit(int nr, const unsigned long * addr)
|
|
{
|
|
int mask;
|
|
|
|
addr += nr >> 5;
|
|
mask = 1 << (nr & 0x1f);
|
|
return ((mask & *addr) != 0);
|
|
}
|
|
|
|
/*
|
|
* fls: find last bit set.
|
|
*/
|
|
|
|
#define fls(x) generic_fls(x)
|
|
#define fls64(x) generic_fls64(x)
|
|
|
|
#ifdef __KERNEL__
|
|
|
|
/*
|
|
* ffs: find first bit set. This is defined the same way as
|
|
* the libc and compiler builtin ffs routines, therefore
|
|
* differs in spirit from the above ffz (man ffs).
|
|
*/
|
|
|
|
#define ffs(x) generic_ffs(x)
|
|
|
|
/*
|
|
* hweightN: returns the hamming weight (i.e. the number
|
|
* of bits set) of a N-bit word
|
|
*/
|
|
|
|
#define hweight32(x) generic_hweight32(x)
|
|
#define hweight16(x) generic_hweight16(x)
|
|
#define hweight8(x) generic_hweight8(x)
|
|
|
|
#endif /* __KERNEL__ */
|
|
|
|
#endif /* _ASM_GENERIC_BITOPS_H */
|