arch/x86/include/asm/bitops.h - arm/linux-arm64-legacy - Git at Google

 #ifndef _ASM_X86_BITOPS_H
 #define _ASM_X86_BITOPS_H

 /*
  * Copyright 1992, Linus Torvalds.
  *
  * Note: inlines with more than a single statement should be marked
  * __always_inline to avoid problems with older gcc's inlining heuristics.
  */

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

 #include <linux/compiler.h>
 #include <asm/alternative.h>
 #include <asm/rmwcc.h>
 #include <asm/barrier.h>

 #if BITS_PER_LONG == 32
 # define _BITOPS_LONG_SHIFT 5
 #elif BITS_PER_LONG == 64
 # define _BITOPS_LONG_SHIFT 6
 #else
 # error "Unexpected BITS_PER_LONG"
 #endif

 #define BIT_64(n)			(U64_C(1) << (n))

 /*
  * These have to be done with inline assembly: that way the bit-setting
  * is guaranteed to be atomic. All bit operations return 0 if the bit
  * was cleared before the operation and != 0 if it was not.
  *
  * bit 0 is the LSB of addr; bit 32 is the LSB of (addr+1).
  */

 #if __GNUC__ < 4 || (__GNUC__ == 4 && __GNUC_MINOR__ < 1)
 /* Technically wrong, but this avoids compilation errors on some gcc
    versions. */
 #define BITOP_ADDR(x) "=m" (*(volatile long *) (x))
 #else
 #define BITOP_ADDR(x) "+m" (*(volatile long *) (x))
 #endif

 #define ADDR				BITOP_ADDR(addr)

 /*
  * We do the locked ops that don't return the old value as
  * a mask operation on a byte.
  */
 #define IS_IMMEDIATE(nr)		(__builtin_constant_p(nr))
 #define CONST_MASK_ADDR(nr, addr)	BITOP_ADDR((void *)(addr) + ((nr)>>3))
 #define CONST_MASK(nr)			(1 << ((nr) & 7))

 /**
  * set_bit - Atomically set a bit in memory
  * @nr: the bit to set
  * @addr: the address to start counting from
  *
  * This function is atomic and may not be reordered.  See __set_bit()
  * if you do not require the atomic guarantees.
  *
  * Note: there are no guarantees that this function will not be reordered
  * on non x86 architectures, so if you are writing portable code,
  * make sure not to rely on its reordering guarantees.
  *
  * Note that @nr may be almost arbitrarily large; this function is not
  * restricted to acting on a single-word quantity.
  */
 static __always_inline void
 set_bit(long nr, volatile unsigned long *addr)
 {
 	if (IS_IMMEDIATE(nr)) {
 		asm volatile(LOCK_PREFIX "orb %1,%0"
 			: CONST_MASK_ADDR(nr, addr)
 			: "iq" ((u8)CONST_MASK(nr))
 			: "memory");
 	} else {
 		asm volatile(LOCK_PREFIX "bts %1,%0"
 			: BITOP_ADDR(addr) : "Ir" (nr) : "memory");
 	}
 }

 /**
  * __set_bit - Set a bit in memory
  * @nr: the bit to set
  * @addr: the address to start counting from
  *
  * Unlike set_bit(), this function is non-atomic and may be reordered.
  * If it's called on the same region of memory simultaneously, the effect
  * may be that only one operation succeeds.
  */
 static inline void __set_bit(long nr, volatile unsigned long *addr)
 {
 	asm volatile("bts %1,%0" : ADDR : "Ir" (nr) : "memory");
 }

 /**
  * clear_bit - Clears a bit in memory
  * @nr: Bit to clear
  * @addr: Address to start counting from
  *
  * clear_bit() is atomic and may not be reordered.  However, it does
  * not contain a memory barrier, so if it is used for locking purposes,
  * you should call smp_mb__before_atomic() and/or smp_mb__after_atomic()
  * in order to ensure changes are visible on other processors.
  */
 static __always_inline void
 clear_bit(long nr, volatile unsigned long *addr)
 {
 	if (IS_IMMEDIATE(nr)) {
 		asm volatile(LOCK_PREFIX "andb %1,%0"
 			: CONST_MASK_ADDR(nr, addr)
 			: "iq" ((u8)~CONST_MASK(nr)));
 	} else {
 		asm volatile(LOCK_PREFIX "btr %1,%0"
 			: BITOP_ADDR(addr)
 			: "Ir" (nr));
 	}
 }

 /*
  * clear_bit_unlock - Clears a bit in memory
  * @nr: Bit to clear
  * @addr: Address to start counting from
  *
  * clear_bit() is atomic and implies release semantics before the memory
  * operation. It can be used for an unlock.
  */
 static inline void clear_bit_unlock(long nr, volatile unsigned long *addr)
 {
 	barrier();
 	clear_bit(nr, addr);
 }

 static inline void __clear_bit(long nr, volatile unsigned long *addr)
 {
 	asm volatile("btr %1,%0" : ADDR : "Ir" (nr));
 }

 /*
  * __clear_bit_unlock - Clears a bit in memory
  * @nr: Bit to clear
  * @addr: Address to start counting from
  *
  * __clear_bit() is non-atomic and implies release semantics before the memory
  * operation. It can be used for an unlock if no other CPUs can concurrently
  * modify other bits in the word.
  *
  * No memory barrier is required here, because x86 cannot reorder stores past
  * older loads. Same principle as spin_unlock.
  */
 static inline void __clear_bit_unlock(long nr, volatile unsigned long *addr)
 {
 	barrier();
 	__clear_bit(nr, addr);
 }

 /**
  * __change_bit - Toggle a bit in memory
  * @nr: the bit to change
  * @addr: the address to start counting from
  *
  * Unlike change_bit(), this function is non-atomic and may be reordered.
  * If it's called on the same region of memory simultaneously, the effect
  * may be that only one operation succeeds.
  */
 static inline void __change_bit(long nr, volatile unsigned long *addr)
 {
 	asm volatile("btc %1,%0" : ADDR : "Ir" (nr));
 }

 /**
  * change_bit - Toggle a bit in memory
  * @nr: Bit to change
  * @addr: Address to start counting from
  *
  * change_bit() is atomic and may not be reordered.
  * Note that @nr may be almost arbitrarily large; this function is not
  * restricted to acting on a single-word quantity.
  */
 static inline void change_bit(long nr, volatile unsigned long *addr)
 {
 	if (IS_IMMEDIATE(nr)) {
 		asm volatile(LOCK_PREFIX "xorb %1,%0"
 			: CONST_MASK_ADDR(nr, addr)
 			: "iq" ((u8)CONST_MASK(nr)));
 	} else {
 		asm volatile(LOCK_PREFIX "btc %1,%0"
 			: BITOP_ADDR(addr)
 			: "Ir" (nr));
 	}
 }

 /**
  * test_and_set_bit - Set a bit and return its old value
  * @nr: Bit to set
  * @addr: Address to count from
  *
  * This operation is atomic and cannot be reordered.
  * It also implies a memory barrier.
  */
 static inline int test_and_set_bit(long nr, volatile unsigned long *addr)
 {
 	GEN_BINARY_RMWcc(LOCK_PREFIX "bts", *addr, "Ir", nr, "%0", "c");
 }

 /**
  * test_and_set_bit_lock - Set a bit and return its old value for lock
  * @nr: Bit to set
  * @addr: Address to count from
  *
  * This is the same as test_and_set_bit on x86.
  */
 static __always_inline int
 test_and_set_bit_lock(long nr, volatile unsigned long *addr)
 {
 	return test_and_set_bit(nr, addr);
 }

 /**
  * __test_and_set_bit - Set a bit and return its old value
  * @nr: Bit to set
  * @addr: Address to count from
  *
  * This operation is non-atomic and can be reordered.
  * If two examples of this operation race, one can appear to succeed
  * but actually fail.  You must protect multiple accesses with a lock.
  */
 static inline int __test_and_set_bit(long nr, volatile unsigned long *addr)
 {
 	int oldbit;

 	asm("bts %2,%1\n\t"
 	    "sbb %0,%0"
 	    : "=r" (oldbit), ADDR
 	    : "Ir" (nr));
 	return oldbit;
 }

 /**
  * test_and_clear_bit - Clear a bit and return its old value
  * @nr: Bit to clear
  * @addr: Address to count from
  *
  * This operation is atomic and cannot be reordered.
  * It also implies a memory barrier.
  */
 static inline int test_and_clear_bit(long nr, volatile unsigned long *addr)
 {
 	GEN_BINARY_RMWcc(LOCK_PREFIX "btr", *addr, "Ir", nr, "%0", "c");
 }

 /**
  * __test_and_clear_bit - Clear a bit and return its old value
  * @nr: Bit to clear
  * @addr: Address to count from
  *
  * This operation is non-atomic and can be reordered.
  * If two examples of this operation race, one can appear to succeed
  * but actually fail.  You must protect multiple accesses with a lock.
  *
  * Note: the operation is performed atomically with respect to
  * the local CPU, but not other CPUs. Portable code should not
  * rely on this behaviour.
  * KVM relies on this behaviour on x86 for modifying memory that is also
  * accessed from a hypervisor on the same CPU if running in a VM: don't change
  * this without also updating arch/x86/kernel/kvm.c
  */
 static inline int __test_and_clear_bit(long nr, volatile unsigned long *addr)
 {
 	int oldbit;

 	asm volatile("btr %2,%1\n\t"
 		     "sbb %0,%0"
 		     : "=r" (oldbit), ADDR
 		     : "Ir" (nr));
 	return oldbit;
 }

 /* WARNING: non atomic and it can be reordered! */
 static inline int __test_and_change_bit(long nr, volatile unsigned long *addr)
 {
 	int oldbit;

 	asm volatile("btc %2,%1\n\t"
 		     "sbb %0,%0"
 		     : "=r" (oldbit), ADDR
 		     : "Ir" (nr) : "memory");

 	return oldbit;
 }

 /**
  * test_and_change_bit - Change a bit and return its old value
  * @nr: Bit to change
  * @addr: Address to count from
  *
  * This operation is atomic and cannot be reordered.
  * It also implies a memory barrier.
  */
 static inline int test_and_change_bit(long nr, volatile unsigned long *addr)
 {
 	GEN_BINARY_RMWcc(LOCK_PREFIX "btc", *addr, "Ir", nr, "%0", "c");
 }

 static __always_inline int constant_test_bit(long nr, const volatile unsigned long *addr)
 {
 	return ((1UL << (nr & (BITS_PER_LONG-1))) &
 		(addr[nr >> _BITOPS_LONG_SHIFT])) != 0;
 }

 static inline int variable_test_bit(long nr, volatile const unsigned long *addr)
 {
 	int oldbit;

 	asm volatile("bt %2,%1\n\t"
 		     "sbb %0,%0"
 		     : "=r" (oldbit)
 		     : "m" (*(unsigned long *)addr), "Ir" (nr));

 	return oldbit;
 }

 #if 0 /* Fool kernel-doc since it doesn't do macros yet */
 /**
  * test_bit - Determine whether a bit is set
  * @nr: bit number to test
  * @addr: Address to start counting from
  */
 static int test_bit(int nr, const volatile unsigned long *addr);
 #endif

 #define test_bit(nr, addr)			\
 	(__builtin_constant_p((nr))		\
 	 ? constant_test_bit((nr), (addr))	\
 	 : variable_test_bit((nr), (addr)))

 /**
  * __ffs - find first set bit in word
  * @word: The word to search
  *
  * Undefined if no bit exists, so code should check against 0 first.
  */
 static inline unsigned long __ffs(unsigned long word)
 {
 	asm("rep; bsf %1,%0"
 		: "=r" (word)
 		: "rm" (word));
 	return word;
 }

 /**
  * ffz - find first zero bit in word
  * @word: The word to search
  *
  * Undefined if no zero exists, so code should check against ~0UL first.
  */
 static inline unsigned long ffz(unsigned long word)
 {
 	asm("rep; bsf %1,%0"
 		: "=r" (word)
 		: "r" (~word));
 	return word;
 }

 /*
  * __fls: find last set bit in word
  * @word: The word to search
  *
  * Undefined if no set bit exists, so code should check against 0 first.
  */
 static inline unsigned long __fls(unsigned long word)
 {
 	asm("bsr %1,%0"
 	    : "=r" (word)
 	    : "rm" (word));
 	return word;
 }

 #undef ADDR

 #ifdef __KERNEL__
 /**
  * ffs - find first set bit in word
  * @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 other bitops.
  *
  * ffs(value) returns 0 if value is 0 or the position of the first
  * set bit if value is nonzero. The first (least significant) bit
  * is at position 1.
  */
 static inline int ffs(int x)
 {
 	int r;

 #ifdef CONFIG_X86_64
 	/*
 	 * AMD64 says BSFL won't clobber the dest reg if x==0; Intel64 says the
 	 * dest reg is undefined if x==0, but their CPU architect says its
 	 * value is written to set it to the same as before, except that the
 	 * top 32 bits will be cleared.
 	 *
 	 * We cannot do this on 32 bits because at the very least some
 	 * 486 CPUs did not behave this way.
 	 */
 	asm("bsfl %1,%0"
 	    : "=r" (r)
 	    : "rm" (x), "0" (-1));
 #elif defined(CONFIG_X86_CMOV)
 	asm("bsfl %1,%0\n\t"
 	    "cmovzl %2,%0"
 	    : "=&r" (r) : "rm" (x), "r" (-1));
 #else
 	asm("bsfl %1,%0\n\t"
 	    "jnz 1f\n\t"
 	    "movl $-1,%0\n"
 	    "1:" : "=r" (r) : "rm" (x));
 #endif
 	return r + 1;
 }

 /**
  * fls - find last set bit in word
  * @x: the word to search
  *
  * This is defined in a similar way as the libc and compiler builtin
  * ffs, but returns the position of the most significant set bit.
  *
  * fls(value) returns 0 if value is 0 or the position of the last
  * set bit if value is nonzero. The last (most significant) bit is
  * at position 32.
  */
 static inline int fls(int x)
 {
 	int r;

 #ifdef CONFIG_X86_64
 	/*
 	 * AMD64 says BSRL won't clobber the dest reg if x==0; Intel64 says the
 	 * dest reg is undefined if x==0, but their CPU architect says its
 	 * value is written to set it to the same as before, except that the
 	 * top 32 bits will be cleared.
 	 *
 	 * We cannot do this on 32 bits because at the very least some
 	 * 486 CPUs did not behave this way.
 	 */
 	asm("bsrl %1,%0"
 	    : "=r" (r)
 	    : "rm" (x), "0" (-1));
 #elif defined(CONFIG_X86_CMOV)
 	asm("bsrl %1,%0\n\t"
 	    "cmovzl %2,%0"
 	    : "=&r" (r) : "rm" (x), "rm" (-1));
 #else
 	asm("bsrl %1,%0\n\t"
 	    "jnz 1f\n\t"
 	    "movl $-1,%0\n"
 	    "1:" : "=r" (r) : "rm" (x));
 #endif
 	return r + 1;
 }

 /**
  * fls64 - find last set bit in a 64-bit word
  * @x: the word to search
  *
  * This is defined in a similar way as the libc and compiler builtin
  * ffsll, but returns the position of the most significant set bit.
  *
  * fls64(value) returns 0 if value is 0 or the position of the last
  * set bit if value is nonzero. The last (most significant) bit is
  * at position 64.
  */
 #ifdef CONFIG_X86_64
 static __always_inline int fls64(__u64 x)
 {
 	int bitpos = -1;
 	/*
 	 * AMD64 says BSRQ won't clobber the dest reg if x==0; Intel64 says the
 	 * dest reg is undefined if x==0, but their CPU architect says its
 	 * value is written to set it to the same as before.
 	 */
 	asm("bsrq %1,%q0"
 	    : "+r" (bitpos)
 	    : "rm" (x));
 	return bitpos + 1;
 }
 #else
 #include <asm-generic/bitops/fls64.h>
 #endif

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

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

 #define ARCH_HAS_FAST_MULTIPLIER 1

 #include <asm/arch_hweight.h>

 #include <asm-generic/bitops/const_hweight.h>

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

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

 #endif /* __KERNEL__ */
 #endif /* _ASM_X86_BITOPS_H */
	#ifndef _ASM_X86_BITOPS_H
	#define _ASM_X86_BITOPS_H

	/*
	* Copyright 1992, Linus Torvalds.
	*
	* Note: inlines with more than a single statement should be marked
	* __always_inline to avoid problems with older gcc's inlining heuristics.
	*/

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

	#include <linux/compiler.h>
	#include <asm/alternative.h>
	#include <asm/rmwcc.h>
	#include <asm/barrier.h>

	#if BITS_PER_LONG == 32
	# define _BITOPS_LONG_SHIFT 5
	#elif BITS_PER_LONG == 64
	# define _BITOPS_LONG_SHIFT 6
	#else
	# error "Unexpected BITS_PER_LONG"
	#endif

	#define BIT_64(n) (U64_C(1) << (n))

	/*
	* These have to be done with inline assembly: that way the bit-setting
	* is guaranteed to be atomic. All bit operations return 0 if the bit
	* was cleared before the operation and != 0 if it was not.
	*
	* bit 0 is the LSB of addr; bit 32 is the LSB of (addr+1).
	*/

	#if __GNUC__ < 4 \|\| (__GNUC__ == 4 && __GNUC_MINOR__ < 1)
	/* Technically wrong, but this avoids compilation errors on some gcc
	versions. */
	#define BITOP_ADDR(x) "=m" ((volatile long ) (x))
	#else
	#define BITOP_ADDR(x) "+m" ((volatile long ) (x))
	#endif

	#define ADDR BITOP_ADDR(addr)

	/*
	* We do the locked ops that don't return the old value as
	* a mask operation on a byte.
	*/
	#define IS_IMMEDIATE(nr) (__builtin_constant_p(nr))
	#define CONST_MASK_ADDR(nr, addr) BITOP_ADDR((void *)(addr) + ((nr)>>3))
	#define CONST_MASK(nr) (1 << ((nr) & 7))

	/**
	* set_bit - Atomically set a bit in memory
	* @nr: the bit to set
	* @addr: the address to start counting from
	*
	* This function is atomic and may not be reordered. See __set_bit()
	* if you do not require the atomic guarantees.
	*
	* Note: there are no guarantees that this function will not be reordered
	* on non x86 architectures, so if you are writing portable code,
	* make sure not to rely on its reordering guarantees.
	*
	* Note that @nr may be almost arbitrarily large; this function is not
	* restricted to acting on a single-word quantity.
	*/
	static __always_inline void
	set_bit(long nr, volatile unsigned long *addr)
	{
	if (IS_IMMEDIATE(nr)) {
	asm volatile(LOCK_PREFIX "orb %1,%0"
	: CONST_MASK_ADDR(nr, addr)
	: "iq" ((u8)CONST_MASK(nr))
	: "memory");
	} else {
	asm volatile(LOCK_PREFIX "bts %1,%0"
	: BITOP_ADDR(addr) : "Ir" (nr) : "memory");
	}
	}

	/**
	* __set_bit - Set a bit in memory
	* @nr: the bit to set
	* @addr: the address to start counting from
	*
	* Unlike set_bit(), this function is non-atomic and may be reordered.
	* If it's called on the same region of memory simultaneously, the effect
	* may be that only one operation succeeds.
	*/
	static inline void __set_bit(long nr, volatile unsigned long *addr)
	{
	asm volatile("bts %1,%0" : ADDR : "Ir" (nr) : "memory");
	}

	/**
	* clear_bit - Clears a bit in memory
	* @nr: Bit to clear
	* @addr: Address to start counting from
	*
	* clear_bit() is atomic and may not be reordered. However, it does
	* not contain a memory barrier, so if it is used for locking purposes,
	* you should call smp_mb__before_atomic() and/or smp_mb__after_atomic()
	* in order to ensure changes are visible on other processors.
	*/
	static __always_inline void
	clear_bit(long nr, volatile unsigned long *addr)
	{
	if (IS_IMMEDIATE(nr)) {
	asm volatile(LOCK_PREFIX "andb %1,%0"
	: CONST_MASK_ADDR(nr, addr)
	: "iq" ((u8)~CONST_MASK(nr)));
	} else {
	asm volatile(LOCK_PREFIX "btr %1,%0"
	: BITOP_ADDR(addr)
	: "Ir" (nr));
	}
	}

	/*
	* clear_bit_unlock - Clears a bit in memory
	* @nr: Bit to clear
	* @addr: Address to start counting from
	*
	* clear_bit() is atomic and implies release semantics before the memory
	* operation. It can be used for an unlock.
	*/
	static inline void clear_bit_unlock(long nr, volatile unsigned long *addr)
	{
	barrier();
	clear_bit(nr, addr);
	}

	static inline void __clear_bit(long nr, volatile unsigned long *addr)
	{
	asm volatile("btr %1,%0" : ADDR : "Ir" (nr));
	}

	/*
	* __clear_bit_unlock - Clears a bit in memory
	* @nr: Bit to clear
	* @addr: Address to start counting from
	*
	* __clear_bit() is non-atomic and implies release semantics before the memory
	* operation. It can be used for an unlock if no other CPUs can concurrently
	* modify other bits in the word.
	*
	* No memory barrier is required here, because x86 cannot reorder stores past
	* older loads. Same principle as spin_unlock.
	*/
	static inline void __clear_bit_unlock(long nr, volatile unsigned long *addr)
	{
	barrier();
	__clear_bit(nr, addr);
	}

	/**
	* __change_bit - Toggle a bit in memory
	* @nr: the bit to change
	* @addr: the address to start counting from
	*
	* Unlike change_bit(), this function is non-atomic and may be reordered.
	* If it's called on the same region of memory simultaneously, the effect
	* may be that only one operation succeeds.
	*/
	static inline void __change_bit(long nr, volatile unsigned long *addr)
	{
	asm volatile("btc %1,%0" : ADDR : "Ir" (nr));
	}

	/**
	* change_bit - Toggle a bit in memory
	* @nr: Bit to change
	* @addr: Address to start counting from
	*
	* change_bit() is atomic and may not be reordered.
	* Note that @nr may be almost arbitrarily large; this function is not
	* restricted to acting on a single-word quantity.
	*/
	static inline void change_bit(long nr, volatile unsigned long *addr)
	{
	if (IS_IMMEDIATE(nr)) {
	asm volatile(LOCK_PREFIX "xorb %1,%0"
	: CONST_MASK_ADDR(nr, addr)
	: "iq" ((u8)CONST_MASK(nr)));
	} else {
	asm volatile(LOCK_PREFIX "btc %1,%0"
	: BITOP_ADDR(addr)
	: "Ir" (nr));
	}
	}

	/**
	* test_and_set_bit - Set a bit and return its old value
	* @nr: Bit to set
	* @addr: Address to count from
	*
	* This operation is atomic and cannot be reordered.
	* It also implies a memory barrier.
	*/
	static inline int test_and_set_bit(long nr, volatile unsigned long *addr)
	{
	GEN_BINARY_RMWcc(LOCK_PREFIX "bts", *addr, "Ir", nr, "%0", "c");
	}

	/**
	* test_and_set_bit_lock - Set a bit and return its old value for lock
	* @nr: Bit to set
	* @addr: Address to count from
	*
	* This is the same as test_and_set_bit on x86.
	*/
	static __always_inline int
	test_and_set_bit_lock(long nr, volatile unsigned long *addr)
	{
	return test_and_set_bit(nr, addr);
	}

	/**
	* __test_and_set_bit - Set a bit and return its old value
	* @nr: Bit to set
	* @addr: Address to count from
	*
	* This operation is non-atomic and can be reordered.
	* If two examples of this operation race, one can appear to succeed
	* but actually fail. You must protect multiple accesses with a lock.
	*/
	static inline int __test_and_set_bit(long nr, volatile unsigned long *addr)
	{
	int oldbit;

	asm("bts %2,%1\n\t"
	"sbb %0,%0"
	: "=r" (oldbit), ADDR
	: "Ir" (nr));
	return oldbit;
	}

	/**
	* test_and_clear_bit - Clear a bit and return its old value
	* @nr: Bit to clear
	* @addr: Address to count from
	*
	* This operation is atomic and cannot be reordered.
	* It also implies a memory barrier.
	*/
	static inline int test_and_clear_bit(long nr, volatile unsigned long *addr)
	{
	GEN_BINARY_RMWcc(LOCK_PREFIX "btr", *addr, "Ir", nr, "%0", "c");
	}

	/**
	* __test_and_clear_bit - Clear a bit and return its old value
	* @nr: Bit to clear
	* @addr: Address to count from
	*
	* This operation is non-atomic and can be reordered.
	* If two examples of this operation race, one can appear to succeed
	* but actually fail. You must protect multiple accesses with a lock.
	*
	* Note: the operation is performed atomically with respect to
	* the local CPU, but not other CPUs. Portable code should not
	* rely on this behaviour.
	* KVM relies on this behaviour on x86 for modifying memory that is also
	* accessed from a hypervisor on the same CPU if running in a VM: don't change
	* this without also updating arch/x86/kernel/kvm.c
	*/
	static inline int __test_and_clear_bit(long nr, volatile unsigned long *addr)
	{
	int oldbit;

	asm volatile("btr %2,%1\n\t"
	"sbb %0,%0"
	: "=r" (oldbit), ADDR
	: "Ir" (nr));
	return oldbit;
	}

	/* WARNING: non atomic and it can be reordered! */
	static inline int __test_and_change_bit(long nr, volatile unsigned long *addr)
	{
	int oldbit;

	asm volatile("btc %2,%1\n\t"
	"sbb %0,%0"
	: "=r" (oldbit), ADDR
	: "Ir" (nr) : "memory");

	return oldbit;
	}

	/**
	* test_and_change_bit - Change a bit and return its old value
	* @nr: Bit to change
	* @addr: Address to count from
	*
	* This operation is atomic and cannot be reordered.
	* It also implies a memory barrier.
	*/
	static inline int test_and_change_bit(long nr, volatile unsigned long *addr)
	{
	GEN_BINARY_RMWcc(LOCK_PREFIX "btc", *addr, "Ir", nr, "%0", "c");
	}

	static __always_inline int constant_test_bit(long nr, const volatile unsigned long *addr)
	{
	return ((1UL << (nr & (BITS_PER_LONG-1))) &
	(addr[nr >> _BITOPS_LONG_SHIFT])) != 0;
	}

	static inline int variable_test_bit(long nr, volatile const unsigned long *addr)
	{
	int oldbit;

	asm volatile("bt %2,%1\n\t"
	"sbb %0,%0"
	: "=r" (oldbit)
	: "m" ((unsigned long )addr), "Ir" (nr));

	return oldbit;
	}

	#if 0 /* Fool kernel-doc since it doesn't do macros yet */
	/**
	* test_bit - Determine whether a bit is set
	* @nr: bit number to test
	* @addr: Address to start counting from
	*/
	static int test_bit(int nr, const volatile unsigned long *addr);
	#endif

	#define test_bit(nr, addr) \
	(__builtin_constant_p((nr)) \
	? constant_test_bit((nr), (addr)) \
	: variable_test_bit((nr), (addr)))

	/**
	* __ffs - find first set bit in word
	* @word: The word to search
	*
	* Undefined if no bit exists, so code should check against 0 first.
	*/
	static inline unsigned long __ffs(unsigned long word)
	{
	asm("rep; bsf %1,%0"
	: "=r" (word)
	: "rm" (word));
	return word;
	}

	/**
	* ffz - find first zero bit in word
	* @word: The word to search
	*
	* Undefined if no zero exists, so code should check against ~0UL first.
	*/
	static inline unsigned long ffz(unsigned long word)
	{
	asm("rep; bsf %1,%0"
	: "=r" (word)
	: "r" (~word));
	return word;
	}

	/*
	* __fls: find last set bit in word
	* @word: The word to search
	*
	* Undefined if no set bit exists, so code should check against 0 first.
	*/
	static inline unsigned long __fls(unsigned long word)
	{
	asm("bsr %1,%0"
	: "=r" (word)
	: "rm" (word));
	return word;
	}

	#undef ADDR

	#ifdef __KERNEL__
	/**
	* ffs - find first set bit in word
	* @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 other bitops.
	*
	* ffs(value) returns 0 if value is 0 or the position of the first
	* set bit if value is nonzero. The first (least significant) bit
	* is at position 1.
	*/
	static inline int ffs(int x)
	{
	int r;

	#ifdef CONFIG_X86_64
	/*
	* AMD64 says BSFL won't clobber the dest reg if x==0; Intel64 says the
	* dest reg is undefined if x==0, but their CPU architect says its
	* value is written to set it to the same as before, except that the
	* top 32 bits will be cleared.
	*
	* We cannot do this on 32 bits because at the very least some
	* 486 CPUs did not behave this way.
	*/
	asm("bsfl %1,%0"
	: "=r" (r)
	: "rm" (x), "0" (-1));
	#elif defined(CONFIG_X86_CMOV)
	asm("bsfl %1,%0\n\t"
	"cmovzl %2,%0"
	: "=&r" (r) : "rm" (x), "r" (-1));
	#else
	asm("bsfl %1,%0\n\t"
	"jnz 1f\n\t"
	"movl $-1,%0\n"
	"1:" : "=r" (r) : "rm" (x));
	#endif
	return r + 1;
	}

	/**
	* fls - find last set bit in word
	* @x: the word to search
	*
	* This is defined in a similar way as the libc and compiler builtin
	* ffs, but returns the position of the most significant set bit.
	*
	* fls(value) returns 0 if value is 0 or the position of the last
	* set bit if value is nonzero. The last (most significant) bit is
	* at position 32.
	*/
	static inline int fls(int x)
	{
	int r;

	#ifdef CONFIG_X86_64
	/*
	* AMD64 says BSRL won't clobber the dest reg if x==0; Intel64 says the
	* dest reg is undefined if x==0, but their CPU architect says its
	* value is written to set it to the same as before, except that the
	* top 32 bits will be cleared.
	*
	* We cannot do this on 32 bits because at the very least some
	* 486 CPUs did not behave this way.
	*/
	asm("bsrl %1,%0"
	: "=r" (r)
	: "rm" (x), "0" (-1));
	#elif defined(CONFIG_X86_CMOV)
	asm("bsrl %1,%0\n\t"
	"cmovzl %2,%0"
	: "=&r" (r) : "rm" (x), "rm" (-1));
	#else
	asm("bsrl %1,%0\n\t"
	"jnz 1f\n\t"
	"movl $-1,%0\n"
	"1:" : "=r" (r) : "rm" (x));
	#endif
	return r + 1;
	}

	/**
	* fls64 - find last set bit in a 64-bit word
	* @x: the word to search
	*
	* This is defined in a similar way as the libc and compiler builtin
	* ffsll, but returns the position of the most significant set bit.
	*
	* fls64(value) returns 0 if value is 0 or the position of the last
	* set bit if value is nonzero. The last (most significant) bit is
	* at position 64.
	*/
	#ifdef CONFIG_X86_64
	static __always_inline int fls64(__u64 x)
	{
	int bitpos = -1;
	/*
	* AMD64 says BSRQ won't clobber the dest reg if x==0; Intel64 says the
	* dest reg is undefined if x==0, but their CPU architect says its
	* value is written to set it to the same as before.
	*/
	asm("bsrq %1,%q0"
	: "+r" (bitpos)
	: "rm" (x));
	return bitpos + 1;
	}
	#else
	#include <asm-generic/bitops/fls64.h>
	#endif

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

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

	#define ARCH_HAS_FAST_MULTIPLIER 1

	#include <asm/arch_hweight.h>

	#include <asm-generic/bitops/const_hweight.h>

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

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

	#endif /* __KERNEL__ */
	#endif /* _ASM_X86_BITOPS_H */