1. 根目录:
2. arch
3. c6x
4. include
5. asm
6. bitops.h

/*
 *  Port on Texas Instruments TMS320C6x architecture
 *
 *  Copyright (C) 2004, 2009, 2010 Texas Instruments Incorporated
 *  Author: Aurelien Jacquiot (aurelien.jacquiot@jaluna.com)
 *
 *  This program is free software; you can redistribute it and/or modify
 *  it under the terms of the GNU General Public License version 2 as
 *  published by the Free Software Foundation.
 */
#ifndef _ASM_C6X_BITOPS_H
#define _ASM_C6X_BITOPS_H

#ifdef __KERNEL__

#include <linux/bitops.h>

#include <asm/byteorder.h>

/*
 * clear_bit() doesn't provide any barrier for the compiler.
 */
#define smp_mb__before_clear_bit() barrier()
#define smp_mb__after_clear_bit()  barrier()

/*
 * We are lucky, DSP is perfect for bitops: do it in 3 cycles
 */

/**
 * __ffs - find first bit in word.
 * @word: The word to search
 *
 * Undefined if no bit exists, so code should check against 0 first.
 * Note __ffs(0) = undef, __ffs(1) = 0, __ffs(0x80000000) = 31.
 *
 */
static inline unsigned long __ffs(unsigned long x)
{
	asm (" bitr  .M1  %0,%0\n"
	     " nop\n"
	     " lmbd  .L1  1,%0,%0\n"
	     : "+a"(x));

	return x;
}

/*
 * ffz - find first zero in word.
 * @word: The word to search
 *
 * Undefined if no zero exists, so code should check against ~0UL first.
 */
#define ffz(x) __ffs(~(x))

/**
 * fls - find last (most-significant) bit set
 * @x: the word to search
 *
 * This is defined the same way as ffs.
 * Note fls(0) = 0, fls(1) = 1, fls(0x80000000) = 32.
 */
static inline int fls(int x)
{
	if (!x)
		return 0;

	asm (" lmbd  .L1  1,%0,%0\n" : "+a"(x));

	return 32 - x;
}

/**
 * ffs - find first bit set
 * @x: the word to search
 *
 * This is defined the same way as
 * the libc and compiler builtin ffs routines, therefore
 * differs in spirit from the above ffz (man ffs).
 * Note ffs(0) = 0, ffs(1) = 1, ffs(0x80000000) = 32.
 */
static inline int ffs(int x)
{
	if (!x)
		return 0;

	return __ffs(x) + 1;
}

#include <asm-generic/bitops/__fls.h>
#include <asm-generic/bitops/fls64.h>
#include <asm-generic/bitops/find.h>

#include <asm-generic/bitops/sched.h>
#include <asm-generic/bitops/hweight.h>
#include <asm-generic/bitops/lock.h>

#include <asm-generic/bitops/atomic.h>
#include <asm-generic/bitops/non-atomic.h>
#include <asm-generic/bitops/le.h>
#include <asm-generic/bitops/ext2-atomic.h>

#endif /* __KERNEL__ */
#endif /* _ASM_C6X_BITOPS_H */