/*
* 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 - 2005 Tensilica Inc.
*/
#ifndef _XTENSA_BITOPS_H
#define _XTENSA_BITOPS_H
#ifdef __KERNEL__
#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__ int __cntlz (unsigned long x)
{
int lz;
asm ("nsau %0, %1" : "=r" (lz) : "r" (x));
return 31 - lz;
}
#else
static __inline__ int __cntlz (unsigned long x)
{
unsigned long sum, x1, x2, x4, x8, x16;
x1 = x & 0xAAAAAAAA;
x2 = x & 0xCCCCCCCC;
x4 = x & 0xF0F0F0F0;
x8 = x & 0xFF00FF00;
x16 = x & 0xFFFF0000;
sum = x2 ? 2 : 0;
sum += (x16 != 0) * 16;
sum += (x8 != 0) * 8;
sum += (x4 != 0) * 4;
sum += (x1 != 0);
return sum;
}
#endif
/*
* 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)
{
if ((x = ~x) == 0)
return 32;
return __cntlz(x & -x);
}
/*
* __ffs: Find first bit set in word. Return 0 for bit 0
*/
static __inline__ int __ffs(unsigned long x)
{
return __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 __cntlz(x & -x) + 1;
}
/*
* 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 __cntlz(x);
}
#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),(addr))
# define ext2_clear_bit_atomic(lock,nr,addr) test_and_clear_bit((nr),(addr))
#elif defined(__XTENSA_EB__)
# define ext2_set_bit_atomic(lock,nr,addr) test_and_set_bit((nr) ^ 0x18, (addr))
# define ext2_clear_bit_atomic(lock,nr,addr) test_and_clear_bit((nr)^0x18,(addr))
#else
# error processor byte order undefined!
#endif
#include <asm-generic/bitops/hweight.h>
#include <asm-generic/bitops/sched.h>
#include <asm-generic/bitops/minix.h>
#endif /* __KERNEL__ */
#endif /* _XTENSA_BITOPS_H */
