Viewing file:  bitops.h (2.79 KB) -rw-r--r--
Select action/file-type:
 (+) |  (+) |  (+) | Code (+) | Session (+) |  (+) | SDB (+) |  (+) |  (+) |  (+) |  (+) |  (+) |
/*
* include/asm-xtensa/bitops.h
*
* Atomic operations that C can't guarantee us.Useful for resource counting etc.
*
* This file is subject to the terms and conditions of the GNU General Public
* License. See the file "COPYING" in the main directory of this archive
* for more details.
*
* Copyright (C) 2001 - 2007 Tensilica Inc.
*/
#ifndef _XTENSA_BITOPS_H
#define _XTENSA_BITOPS_H
#ifdef __KERNEL__
#ifndef _LINUX_BITOPS_H
#error only <linux/bitops.h> can be included directly
#endif
#include <asm/processor.h>
#include <asm/byteorder.h>
#include <asm/system.h>
#ifdef CONFIG_SMP
# error SMP not supported on this architecture
#endif
#define smp_mb__before_clear_bit() barrier()
#define smp_mb__after_clear_bit() barrier()
#include <asm-generic/bitops/atomic.h>
#include <asm-generic/bitops/non-atomic.h>
#if XCHAL_HAVE_NSA
static inline unsigned long __cntlz (unsigned long x)
{
int lz;
asm ("nsau %0, %1" : "=r" (lz) : "r" (x));
return lz;
}
/*
* ffz: Find first zero in word. Undefined if no zero exists.
* bit 0 is the LSB of addr; bit 32 is the LSB of (addr+1).
*/
static inline int ffz(unsigned long x)
{
return 31 - __cntlz(~x & -~x);
}
/*
* __ffs: Find first bit set in word. Return 0 for bit 0
*/
static inline int __ffs(unsigned long x)
{
return 31 - __cntlz(x & -x);
}
/*
* ffs: Find first bit set in word. This is defined the same way as
* the libc and compiler builtin ffs routines, therefore
* differs in spirit from the above ffz (man ffs).
*/
static inline int ffs(unsigned long x)
{
return 32 - __cntlz(x & -x);
}
/*
* fls: Find last (most-significant) bit set in word.
* Note fls(0) = 0, fls(1) = 1, fls(0x80000000) = 32.
*/
static inline int fls (unsigned int x)
{
return 32 - __cntlz(x);
}
#else
/* Use the generic implementation if we don't have the nsa/nsau instructions. */
# include <asm-generic/bitops/ffs.h>
# include <asm-generic/bitops/__ffs.h>
# include <asm-generic/bitops/ffz.h>
# include <asm-generic/bitops/fls.h>
#endif
#include <asm-generic/bitops/fls64.h>
#include <asm-generic/bitops/find.h>
#include <asm-generic/bitops/ext2-non-atomic.h>
#ifdef __XTENSA_EL__
# define ext2_set_bit_atomic(lock,nr,addr) \
test_and_set_bit((nr), (unsigned long*)(addr))
# define ext2_clear_bit_atomic(lock,nr,addr) \
test_and_clear_bit((nr), (unsigned long*)(addr))
#elif defined(__XTENSA_EB__)
# define ext2_set_bit_atomic(lock,nr,addr) \
test_and_set_bit((nr) ^ 0x18, (unsigned long*)(addr))
# define ext2_clear_bit_atomic(lock,nr,addr) \
test_and_clear_bit((nr) ^ 0x18, (unsigned long*)(addr))
#else
# error processor byte order undefined!
#endif
#include <asm-generic/bitops/hweight.h>
#include <asm-generic/bitops/lock.h>
#include <asm-generic/bitops/sched.h>
#include <asm-generic/bitops/minix.h>
#endif /* __KERNEL__ */
#endif /* _XTENSA_BITOPS_H */
|