arch/arc/include/asm/bitops.h - kernel/lockdown - Git at Google

 /*
  * Copyright (C) 2004, 2007-2010, 2011-2012 Synopsys, Inc. (www.synopsys.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_BITOPS_H
 #define _ASM_BITOPS_H

 #ifndef _LINUX_BITOPS_H
 #error only <linux/bitops.h> can be included directly
 #endif

 #ifdef __KERNEL__

 #ifndef __ASSEMBLY__

 #include <linux/types.h>
 #include <linux/compiler.h>

 /*
  * Hardware assisted read-modify-write using ARC700 LLOCK/SCOND insns.
  * The Kconfig glue ensures that in SMP, this is only set if the container
  * SoC/platform has cross-core coherent LLOCK/SCOND
  */
 #if defined(CONFIG_ARC_HAS_LLSC)

 static inline void set_bit(unsigned long nr, volatile unsigned long *m)
 {
 	unsigned int temp;

 	m += nr >> 5;

 	if (__builtin_constant_p(nr))
 		nr &= 0x1f;

 	__asm__ __volatile__(
 	"1:	llock   %0, [%1]	\n"
 	"	bset    %0, %0, %2	\n"
 	"	scond   %0, [%1]	\n"
 	"	bnz     1b	\n"
 	: "=&r"(temp)
 	: "r"(m), "ir"(nr)
 	: "cc");
 }

 static inline void clear_bit(unsigned long nr, volatile unsigned long *m)
 {
 	unsigned int temp;

 	m += nr >> 5;

 	if (__builtin_constant_p(nr))
 		nr &= 0x1f;

 	__asm__ __volatile__(
 	"1:	llock   %0, [%1]	\n"
 	"	bclr    %0, %0, %2	\n"
 	"	scond   %0, [%1]	\n"
 	"	bnz     1b	\n"
 	: "=&r"(temp)
 	: "r"(m), "ir"(nr)
 	: "cc");
 }

 static inline void change_bit(unsigned long nr, volatile unsigned long *m)
 {
 	unsigned int temp;

 	m += nr >> 5;

 	if (__builtin_constant_p(nr))
 		nr &= 0x1f;

 	__asm__ __volatile__(
 	"1:	llock   %0, [%1]	\n"
 	"	bxor    %0, %0, %2	\n"
 	"	scond   %0, [%1]	\n"
 	"	bnz     1b		\n"
 	: "=&r"(temp)
 	: "r"(m), "ir"(nr)
 	: "cc");
 }

 /*
  * Semantically:
  *    Test the bit
  *    if clear
  *        set it and return 0 (old value)
  *    else
  *        return 1 (old value).
  *
  * Since ARC lacks a equivalent h/w primitive, the bit is set unconditionally
  * and the old value of bit is returned
  */
 static inline int test_and_set_bit(unsigned long nr, volatile unsigned long *m)
 {
 	unsigned long old, temp;

 	m += nr >> 5;

 	if (__builtin_constant_p(nr))
 		nr &= 0x1f;

 	__asm__ __volatile__(
 	"1:	llock   %0, [%2]	\n"
 	"	bset    %1, %0, %3	\n"
 	"	scond   %1, [%2]	\n"
 	"	bnz     1b		\n"
 	: "=&r"(old), "=&r"(temp)
 	: "r"(m), "ir"(nr)
 	: "cc");

 	return (old & (1 << nr)) != 0;
 }

 static inline int
 test_and_clear_bit(unsigned long nr, volatile unsigned long *m)
 {
 	unsigned int old, temp;

 	m += nr >> 5;

 	if (__builtin_constant_p(nr))
 		nr &= 0x1f;

 	__asm__ __volatile__(
 	"1:	llock   %0, [%2]	\n"
 	"	bclr    %1, %0, %3	\n"
 	"	scond   %1, [%2]	\n"
 	"	bnz     1b		\n"
 	: "=&r"(old), "=&r"(temp)
 	: "r"(m), "ir"(nr)
 	: "cc");

 	return (old & (1 << nr)) != 0;
 }

 static inline int
 test_and_change_bit(unsigned long nr, volatile unsigned long *m)
 {
 	unsigned int old, temp;

 	m += nr >> 5;

 	if (__builtin_constant_p(nr))
 		nr &= 0x1f;

 	__asm__ __volatile__(
 	"1:	llock   %0, [%2]	\n"
 	"	bxor    %1, %0, %3	\n"
 	"	scond   %1, [%2]	\n"
 	"	bnz     1b		\n"
 	: "=&r"(old), "=&r"(temp)
 	: "r"(m), "ir"(nr)
 	: "cc");

 	return (old & (1 << nr)) != 0;
 }

 #else	/* !CONFIG_ARC_HAS_LLSC */

 #include <asm/smp.h>

 /*
  * Non hardware assisted Atomic-R-M-W
  * Locking would change to irq-disabling only (UP) and spinlocks (SMP)
  *
  * There's "significant" micro-optimization in writing our own variants of
  * bitops (over generic variants)
  *
  * (1) The generic APIs have "signed" @nr while we have it "unsigned"
  *     This avoids extra code to be generated for pointer arithmatic, since
  *     is "not sure" that index is NOT -ve
  * (2) Utilize the fact that ARCompact bit fidding insn (BSET/BCLR/ASL) etc
  *     only consider bottom 5 bits of @nr, so NO need to mask them off.
  *     (GCC Quirk: however for constant @nr we still need to do the masking
  *             at compile time)
  */

 static inline void set_bit(unsigned long nr, volatile unsigned long *m)
 {
 	unsigned long temp, flags;
 	m += nr >> 5;

 	if (__builtin_constant_p(nr))
 		nr &= 0x1f;

 	bitops_lock(flags);

 	temp = *m;
 	*m = temp | (1UL << nr);

 	bitops_unlock(flags);
 }

 static inline void clear_bit(unsigned long nr, volatile unsigned long *m)
 {
 	unsigned long temp, flags;
 	m += nr >> 5;

 	if (__builtin_constant_p(nr))
 		nr &= 0x1f;

 	bitops_lock(flags);

 	temp = *m;
 	*m = temp & ~(1UL << nr);

 	bitops_unlock(flags);
 }

 static inline void change_bit(unsigned long nr, volatile unsigned long *m)
 {
 	unsigned long temp, flags;
 	m += nr >> 5;

 	if (__builtin_constant_p(nr))
 		nr &= 0x1f;

 	bitops_lock(flags);

 	temp = *m;
 	*m = temp ^ (1UL << nr);

 	bitops_unlock(flags);
 }

 static inline int test_and_set_bit(unsigned long nr, volatile unsigned long *m)
 {
 	unsigned long old, flags;
 	m += nr >> 5;

 	if (__builtin_constant_p(nr))
 		nr &= 0x1f;

 	bitops_lock(flags);

 	old = *m;
 	*m = old | (1 << nr);

 	bitops_unlock(flags);

 	return (old & (1 << nr)) != 0;
 }

 static inline int
 test_and_clear_bit(unsigned long nr, volatile unsigned long *m)
 {
 	unsigned long old, flags;
 	m += nr >> 5;

 	if (__builtin_constant_p(nr))
 		nr &= 0x1f;

 	bitops_lock(flags);

 	old = *m;
 	*m = old & ~(1 << nr);

 	bitops_unlock(flags);

 	return (old & (1 << nr)) != 0;
 }

 static inline int
 test_and_change_bit(unsigned long nr, volatile unsigned long *m)
 {
 	unsigned long old, flags;
 	m += nr >> 5;

 	if (__builtin_constant_p(nr))
 		nr &= 0x1f;

 	bitops_lock(flags);

 	old = *m;
 	*m = old ^ (1 << nr);

 	bitops_unlock(flags);

 	return (old & (1 << nr)) != 0;
 }

 #endif /* CONFIG_ARC_HAS_LLSC */

 /***************************************
  * Non atomic variants
  **************************************/

 static inline void __set_bit(unsigned long nr, volatile unsigned long *m)
 {
 	unsigned long temp;
 	m += nr >> 5;

 	if (__builtin_constant_p(nr))
 		nr &= 0x1f;

 	temp = *m;
 	*m = temp | (1UL << nr);
 }

 static inline void __clear_bit(unsigned long nr, volatile unsigned long *m)
 {
 	unsigned long temp;
 	m += nr >> 5;

 	if (__builtin_constant_p(nr))
 		nr &= 0x1f;

 	temp = *m;
 	*m = temp & ~(1UL << nr);
 }

 static inline void __change_bit(unsigned long nr, volatile unsigned long *m)
 {
 	unsigned long temp;
 	m += nr >> 5;

 	if (__builtin_constant_p(nr))
 		nr &= 0x1f;

 	temp = *m;
 	*m = temp ^ (1UL << nr);
 }

 static inline int
 __test_and_set_bit(unsigned long nr, volatile unsigned long *m)
 {
 	unsigned long old;
 	m += nr >> 5;

 	if (__builtin_constant_p(nr))
 		nr &= 0x1f;

 	old = *m;
 	*m = old | (1 << nr);

 	return (old & (1 << nr)) != 0;
 }

 static inline int
 __test_and_clear_bit(unsigned long nr, volatile unsigned long *m)
 {
 	unsigned long old;
 	m += nr >> 5;

 	if (__builtin_constant_p(nr))
 		nr &= 0x1f;

 	old = *m;
 	*m = old & ~(1 << nr);

 	return (old & (1 << nr)) != 0;
 }

 static inline int
 __test_and_change_bit(unsigned long nr, volatile unsigned long *m)
 {
 	unsigned long old;
 	m += nr >> 5;

 	if (__builtin_constant_p(nr))
 		nr &= 0x1f;

 	old = *m;
 	*m = old ^ (1 << nr);

 	return (old & (1 << nr)) != 0;
 }

 /*
  * This routine doesn't need to be atomic.
  */
 static inline int
 __constant_test_bit(unsigned int nr, const volatile unsigned long *addr)
 {
 	return ((1UL << (nr & 31)) &
 		(((const volatile unsigned int *)addr)[nr >> 5])) != 0;
 }

 static inline int
 __test_bit(unsigned int nr, const volatile unsigned long *addr)
 {
 	unsigned long mask;

 	addr += nr >> 5;

 	/* ARC700 only considers 5 bits in bit-fiddling insn */
 	mask = 1 << nr;

 	return ((mask & *addr) != 0);
 }

 #define test_bit(nr, addr)	(__builtin_constant_p(nr) ? \
 					__constant_test_bit((nr), (addr)) : \
 					__test_bit((nr), (addr)))

 /*
  * Count the number of zeros, starting from MSB
  * Helper for fls( ) friends
  * This is a pure count, so (1-32) or (0-31) doesn't apply
  * It could be 0 to 32, based on num of 0's in there
  * clz(0x8000_0000) = 0, clz(0xFFFF_FFFF)=0, clz(0) = 32, clz(1) = 31
  */
 static inline __attribute__ ((const)) int clz(unsigned int x)
 {
 	unsigned int res;

 	__asm__ __volatile__(
 	"	norm.f  %0, %1		\n"
 	"	mov.n   %0, 0		\n"
 	"	add.p   %0, %0, 1	\n"
 	: "=r"(res)
 	: "r"(x)
 	: "cc");

 	return res;
 }

 static inline int constant_fls(int x)
 {
 	int r = 32;

 	if (!x)
 		return 0;
 	if (!(x & 0xffff0000u)) {
 		x <<= 16;
 		r -= 16;
 	}
 	if (!(x & 0xff000000u)) {
 		x <<= 8;
 		r -= 8;
 	}
 	if (!(x & 0xf0000000u)) {
 		x <<= 4;
 		r -= 4;
 	}
 	if (!(x & 0xc0000000u)) {
 		x <<= 2;
 		r -= 2;
 	}
 	if (!(x & 0x80000000u)) {
 		x <<= 1;
 		r -= 1;
 	}
 	return r;
 }

 /*
  * fls = Find Last Set in word
  * @result: [1-32]
  * fls(1) = 1, fls(0x80000000) = 32, fls(0) = 0
  */
 static inline __attribute__ ((const)) int fls(unsigned long x)
 {
 	if (__builtin_constant_p(x))
 	       return constant_fls(x);

 	return 32 - clz(x);
 }

 /*
  * __fls: Similar to fls, but zero based (0-31)
  */
 static inline __attribute__ ((const)) int __fls(unsigned long x)
 {
 	if (!x)
 		return 0;
 	else
 		return fls(x) - 1;
 }

 /*
  * ffs = Find First Set in word (LSB to MSB)
  * @result: [1-32], 0 if all 0's
  */
 #define ffs(x)	({ unsigned long __t = (x); fls(__t & -__t); })

 /*
  * __ffs: Similar to ffs, but zero based (0-31)
  */
 static inline __attribute__ ((const)) int __ffs(unsigned long word)
 {
 	if (!word)
 		return word;

 	return ffs(word) - 1;
 }

 /*
  * ffz = Find First Zero in word.
  * @return:[0-31], 32 if all 1's
  */
 #define ffz(x)	__ffs(~(x))

 /* TODO does this affect uni-processor code */
 #define smp_mb__before_clear_bit()  barrier()
 #define smp_mb__after_clear_bit()   barrier()

 #include <asm-generic/bitops/hweight.h>
 #include <asm-generic/bitops/fls64.h>
 #include <asm-generic/bitops/sched.h>
 #include <asm-generic/bitops/lock.h>

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

 #endif /* !__ASSEMBLY__ */

 #endif /* __KERNEL__ */

 #endif
	/*
	* Copyright (C) 2004, 2007-2010, 2011-2012 Synopsys, Inc. (www.synopsys.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_BITOPS_H
	#define _ASM_BITOPS_H

	#ifndef _LINUX_BITOPS_H
	#error only <linux/bitops.h> can be included directly
	#endif

	#ifdef __KERNEL__

	#ifndef __ASSEMBLY__

	#include <linux/types.h>
	#include <linux/compiler.h>

	/*
	* Hardware assisted read-modify-write using ARC700 LLOCK/SCOND insns.
	* The Kconfig glue ensures that in SMP, this is only set if the container
	* SoC/platform has cross-core coherent LLOCK/SCOND
	*/
	#if defined(CONFIG_ARC_HAS_LLSC)

	static inline void set_bit(unsigned long nr, volatile unsigned long *m)
	{
	unsigned int temp;

	m += nr >> 5;

	if (__builtin_constant_p(nr))
	nr &= 0x1f;

	__asm__ __volatile__(
	"1: llock %0, [%1] \n"
	" bset %0, %0, %2 \n"
	" scond %0, [%1] \n"
	" bnz 1b \n"
	: "=&r"(temp)
	: "r"(m), "ir"(nr)
	: "cc");
	}

	static inline void clear_bit(unsigned long nr, volatile unsigned long *m)
	{
	unsigned int temp;

	m += nr >> 5;

	if (__builtin_constant_p(nr))
	nr &= 0x1f;

	__asm__ __volatile__(
	"1: llock %0, [%1] \n"
	" bclr %0, %0, %2 \n"
	" scond %0, [%1] \n"
	" bnz 1b \n"
	: "=&r"(temp)
	: "r"(m), "ir"(nr)
	: "cc");
	}

	static inline void change_bit(unsigned long nr, volatile unsigned long *m)
	{
	unsigned int temp;

	m += nr >> 5;

	if (__builtin_constant_p(nr))
	nr &= 0x1f;

	__asm__ __volatile__(
	"1: llock %0, [%1] \n"
	" bxor %0, %0, %2 \n"
	" scond %0, [%1] \n"
	" bnz 1b \n"
	: "=&r"(temp)
	: "r"(m), "ir"(nr)
	: "cc");
	}

	/*
	* Semantically:
	* Test the bit
	* if clear
	* set it and return 0 (old value)
	* else
	* return 1 (old value).
	*
	* Since ARC lacks a equivalent h/w primitive, the bit is set unconditionally
	* and the old value of bit is returned
	*/
	static inline int test_and_set_bit(unsigned long nr, volatile unsigned long *m)
	{
	unsigned long old, temp;

	m += nr >> 5;

	if (__builtin_constant_p(nr))
	nr &= 0x1f;

	__asm__ __volatile__(
	"1: llock %0, [%2] \n"
	" bset %1, %0, %3 \n"
	" scond %1, [%2] \n"
	" bnz 1b \n"
	: "=&r"(old), "=&r"(temp)
	: "r"(m), "ir"(nr)
	: "cc");

	return (old & (1 << nr)) != 0;
	}

	static inline int
	test_and_clear_bit(unsigned long nr, volatile unsigned long *m)
	{
	unsigned int old, temp;

	m += nr >> 5;

	if (__builtin_constant_p(nr))
	nr &= 0x1f;

	__asm__ __volatile__(
	"1: llock %0, [%2] \n"
	" bclr %1, %0, %3 \n"
	" scond %1, [%2] \n"
	" bnz 1b \n"
	: "=&r"(old), "=&r"(temp)
	: "r"(m), "ir"(nr)
	: "cc");

	return (old & (1 << nr)) != 0;
	}

	static inline int
	test_and_change_bit(unsigned long nr, volatile unsigned long *m)
	{
	unsigned int old, temp;

	m += nr >> 5;

	if (__builtin_constant_p(nr))
	nr &= 0x1f;

	__asm__ __volatile__(
	"1: llock %0, [%2] \n"
	" bxor %1, %0, %3 \n"
	" scond %1, [%2] \n"
	" bnz 1b \n"
	: "=&r"(old), "=&r"(temp)
	: "r"(m), "ir"(nr)
	: "cc");

	return (old & (1 << nr)) != 0;
	}

	#else /* !CONFIG_ARC_HAS_LLSC */

	#include <asm/smp.h>

	/*
	* Non hardware assisted Atomic-R-M-W
	* Locking would change to irq-disabling only (UP) and spinlocks (SMP)
	*
	* There's "significant" micro-optimization in writing our own variants of
	* bitops (over generic variants)
	*
	* (1) The generic APIs have "signed" @nr while we have it "unsigned"
	* This avoids extra code to be generated for pointer arithmatic, since
	* is "not sure" that index is NOT -ve
	* (2) Utilize the fact that ARCompact bit fidding insn (BSET/BCLR/ASL) etc
	* only consider bottom 5 bits of @nr, so NO need to mask them off.
	* (GCC Quirk: however for constant @nr we still need to do the masking
	* at compile time)
	*/

	static inline void set_bit(unsigned long nr, volatile unsigned long *m)
	{
	unsigned long temp, flags;
	m += nr >> 5;

	if (__builtin_constant_p(nr))
	nr &= 0x1f;

	bitops_lock(flags);

	temp = *m;
	*m = temp \| (1UL << nr);

	bitops_unlock(flags);
	}

	static inline void clear_bit(unsigned long nr, volatile unsigned long *m)
	{
	unsigned long temp, flags;
	m += nr >> 5;

	if (__builtin_constant_p(nr))
	nr &= 0x1f;

	bitops_lock(flags);

	temp = *m;
	*m = temp & ~(1UL << nr);

	bitops_unlock(flags);
	}

	static inline void change_bit(unsigned long nr, volatile unsigned long *m)
	{
	unsigned long temp, flags;
	m += nr >> 5;

	if (__builtin_constant_p(nr))
	nr &= 0x1f;

	bitops_lock(flags);

	temp = *m;
	*m = temp ^ (1UL << nr);

	bitops_unlock(flags);
	}

	static inline int test_and_set_bit(unsigned long nr, volatile unsigned long *m)
	{
	unsigned long old, flags;
	m += nr >> 5;

	if (__builtin_constant_p(nr))
	nr &= 0x1f;

	bitops_lock(flags);

	old = *m;
	*m = old \| (1 << nr);

	bitops_unlock(flags);

	return (old & (1 << nr)) != 0;
	}

	static inline int
	test_and_clear_bit(unsigned long nr, volatile unsigned long *m)
	{
	unsigned long old, flags;
	m += nr >> 5;

	if (__builtin_constant_p(nr))
	nr &= 0x1f;

	bitops_lock(flags);

	old = *m;
	*m = old & ~(1 << nr);

	bitops_unlock(flags);

	return (old & (1 << nr)) != 0;
	}

	static inline int
	test_and_change_bit(unsigned long nr, volatile unsigned long *m)
	{
	unsigned long old, flags;
	m += nr >> 5;

	if (__builtin_constant_p(nr))
	nr &= 0x1f;

	bitops_lock(flags);

	old = *m;
	*m = old ^ (1 << nr);

	bitops_unlock(flags);

	return (old & (1 << nr)) != 0;
	}

	#endif /* CONFIG_ARC_HAS_LLSC */

	/***************************************
	* Non atomic variants
	**************************************/

	static inline void __set_bit(unsigned long nr, volatile unsigned long *m)
	{
	unsigned long temp;
	m += nr >> 5;

	if (__builtin_constant_p(nr))
	nr &= 0x1f;

	temp = *m;
	*m = temp \| (1UL << nr);
	}

	static inline void __clear_bit(unsigned long nr, volatile unsigned long *m)
	{
	unsigned long temp;
	m += nr >> 5;

	if (__builtin_constant_p(nr))
	nr &= 0x1f;

	temp = *m;
	*m = temp & ~(1UL << nr);
	}

	static inline void __change_bit(unsigned long nr, volatile unsigned long *m)
	{
	unsigned long temp;
	m += nr >> 5;

	if (__builtin_constant_p(nr))
	nr &= 0x1f;

	temp = *m;
	*m = temp ^ (1UL << nr);
	}

	static inline int
	__test_and_set_bit(unsigned long nr, volatile unsigned long *m)
	{
	unsigned long old;
	m += nr >> 5;

	if (__builtin_constant_p(nr))
	nr &= 0x1f;

	old = *m;
	*m = old \| (1 << nr);

	return (old & (1 << nr)) != 0;
	}

	static inline int
	__test_and_clear_bit(unsigned long nr, volatile unsigned long *m)
	{
	unsigned long old;
	m += nr >> 5;

	if (__builtin_constant_p(nr))
	nr &= 0x1f;

	old = *m;
	*m = old & ~(1 << nr);

	return (old & (1 << nr)) != 0;
	}

	static inline int
	__test_and_change_bit(unsigned long nr, volatile unsigned long *m)
	{
	unsigned long old;
	m += nr >> 5;

	if (__builtin_constant_p(nr))
	nr &= 0x1f;

	old = *m;
	*m = old ^ (1 << nr);

	return (old & (1 << nr)) != 0;
	}

	/*
	* This routine doesn't need to be atomic.
	*/
	static inline int
	__constant_test_bit(unsigned int nr, const volatile unsigned long *addr)
	{
	return ((1UL << (nr & 31)) &
	(((const volatile unsigned int *)addr)[nr >> 5])) != 0;
	}

	static inline int
	__test_bit(unsigned int nr, const volatile unsigned long *addr)
	{
	unsigned long mask;

	addr += nr >> 5;

	/* ARC700 only considers 5 bits in bit-fiddling insn */
	mask = 1 << nr;

	return ((mask & *addr) != 0);
	}

	#define test_bit(nr, addr) (__builtin_constant_p(nr) ? \
	__constant_test_bit((nr), (addr)) : \
	__test_bit((nr), (addr)))

	/*
	* Count the number of zeros, starting from MSB
	* Helper for fls( ) friends
	* This is a pure count, so (1-32) or (0-31) doesn't apply
	* It could be 0 to 32, based on num of 0's in there
	* clz(0x8000_0000) = 0, clz(0xFFFF_FFFF)=0, clz(0) = 32, clz(1) = 31
	*/
	static inline __attribute__ ((const)) int clz(unsigned int x)
	{
	unsigned int res;

	__asm__ __volatile__(
	" norm.f %0, %1 \n"
	" mov.n %0, 0 \n"
	" add.p %0, %0, 1 \n"
	: "=r"(res)
	: "r"(x)
	: "cc");

	return res;
	}

	static inline int constant_fls(int x)
	{
	int r = 32;

	if (!x)
	return 0;
	if (!(x & 0xffff0000u)) {
	x <<= 16;
	r -= 16;
	}
	if (!(x & 0xff000000u)) {
	x <<= 8;
	r -= 8;
	}
	if (!(x & 0xf0000000u)) {
	x <<= 4;
	r -= 4;
	}
	if (!(x & 0xc0000000u)) {
	x <<= 2;
	r -= 2;
	}
	if (!(x & 0x80000000u)) {
	x <<= 1;
	r -= 1;
	}
	return r;
	}

	/*
	* fls = Find Last Set in word
	* @result: [1-32]
	* fls(1) = 1, fls(0x80000000) = 32, fls(0) = 0
	*/
	static inline __attribute__ ((const)) int fls(unsigned long x)
	{
	if (__builtin_constant_p(x))
	return constant_fls(x);

	return 32 - clz(x);
	}

	/*
	* __fls: Similar to fls, but zero based (0-31)
	*/
	static inline __attribute__ ((const)) int __fls(unsigned long x)
	{
	if (!x)
	return 0;
	else
	return fls(x) - 1;
	}

	/*
	* ffs = Find First Set in word (LSB to MSB)
	* @result: [1-32], 0 if all 0's
	*/
	#define ffs(x) ({ unsigned long __t = (x); fls(__t & -__t); })

	/*
	* __ffs: Similar to ffs, but zero based (0-31)
	*/
	static inline __attribute__ ((const)) int __ffs(unsigned long word)
	{
	if (!word)
	return word;

	return ffs(word) - 1;
	}

	/*
	* ffz = Find First Zero in word.
	* @return:[0-31], 32 if all 1's
	*/
	#define ffz(x) __ffs(~(x))

	/* TODO does this affect uni-processor code */
	#define smp_mb__before_clear_bit() barrier()
	#define smp_mb__after_clear_bit() barrier()

	#include <asm-generic/bitops/hweight.h>
	#include <asm-generic/bitops/fls64.h>
	#include <asm-generic/bitops/sched.h>
	#include <asm-generic/bitops/lock.h>

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

	#endif /* !__ASSEMBLY__ */

	#endif /* __KERNEL__ */

	#endif