linux/include/asm-x86_64/bitops.h

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#ifndef _X86_64_BITOPS_H
#define _X86_64_BITOPS_H
/*
* Copyright 1992, Linus Torvalds.
*/
#include <asm/alternative.h>
#if __GNUC__ < 4 || (__GNUC__ == 4 && __GNUC_MINOR__ < 1)
/* Technically wrong, but this avoids compilation errors on some gcc
versions. */
#define ADDR "=m" (*(volatile long *) addr)
#else
#define ADDR "+m" (*(volatile long *) addr)
#endif
/**
* 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 that @nr may be almost arbitrarily large; this function is not
* restricted to acting on a single-word quantity.
*/
static __inline__ void set_bit(int nr, volatile void * addr)
{
__asm__ __volatile__( LOCK_PREFIX
"btsl %1,%0"
:ADDR
:"dIr" (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(int nr, volatile void * addr)
{
__asm__ volatile(
"btsl %1,%0"
:ADDR
:"dIr" (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_clear_bit() and/or smp_mb__after_clear_bit()
* in order to ensure changes are visible on other processors.
*/
static __inline__ void clear_bit(int nr, volatile void * addr)
{
__asm__ __volatile__( LOCK_PREFIX
"btrl %1,%0"
:ADDR
:"dIr" (nr));
}
static __inline__ void __clear_bit(int nr, volatile void * addr)
{
__asm__ __volatile__(
"btrl %1,%0"
:ADDR
:"dIr" (nr));
}
#define smp_mb__before_clear_bit() barrier()
#define smp_mb__after_clear_bit() barrier()
/**
* __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(int nr, volatile void * addr)
{
__asm__ __volatile__(
"btcl %1,%0"
:ADDR
:"dIr" (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(int nr, volatile void * addr)
{
__asm__ __volatile__( LOCK_PREFIX
"btcl %1,%0"
:ADDR
:"dIr" (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(int nr, volatile void * addr)
{
int oldbit;
__asm__ __volatile__( LOCK_PREFIX
"btsl %2,%1\n\tsbbl %0,%0"
:"=r" (oldbit),ADDR
:"dIr" (nr) : "memory");
return oldbit;
}
/**
* __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(int nr, volatile void * addr)
{
int oldbit;
__asm__(
"btsl %2,%1\n\tsbbl %0,%0"
:"=r" (oldbit),ADDR
:"dIr" (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(int nr, volatile void * addr)
{
int oldbit;
__asm__ __volatile__( LOCK_PREFIX
"btrl %2,%1\n\tsbbl %0,%0"
:"=r" (oldbit),ADDR
:"dIr" (nr) : "memory");
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 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_clear_bit(int nr, volatile void * addr)
{
int oldbit;
__asm__(
"btrl %2,%1\n\tsbbl %0,%0"
:"=r" (oldbit),ADDR
:"dIr" (nr));
return oldbit;
}
/* WARNING: non atomic and it can be reordered! */
static __inline__ int __test_and_change_bit(int nr, volatile void * addr)
{
int oldbit;
__asm__ __volatile__(
"btcl %2,%1\n\tsbbl %0,%0"
:"=r" (oldbit),ADDR
:"dIr" (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(int nr, volatile void * addr)
{
int oldbit;
__asm__ __volatile__( LOCK_PREFIX
"btcl %2,%1\n\tsbbl %0,%0"
:"=r" (oldbit),ADDR
:"dIr" (nr) : "memory");
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 void * addr);
#endif
static __inline__ int constant_test_bit(int nr, const volatile void * addr)
{
return ((1UL << (nr & 31)) & (((const volatile unsigned int *) addr)[nr >> 5])) != 0;
}
static __inline__ int variable_test_bit(int nr, volatile const void * addr)
{
int oldbit;
__asm__ __volatile__(
"btl %2,%1\n\tsbbl %0,%0"
:"=r" (oldbit)
:"m" (*(volatile long *)addr),"dIr" (nr));
return oldbit;
}
#define test_bit(nr,addr) \
(__builtin_constant_p(nr) ? \
constant_test_bit((nr),(addr)) : \
variable_test_bit((nr),(addr)))
#undef ADDR
extern long find_first_zero_bit(const unsigned long * addr, unsigned long size);
extern long find_next_zero_bit (const unsigned long * addr, long size, long offset);
extern long find_first_bit(const unsigned long * addr, unsigned long size);
extern long find_next_bit(const unsigned long * addr, long size, long offset);
/* return index of first bet set in val or max when no bit is set */
static inline unsigned long __scanbit(unsigned long val, unsigned long max)
{
asm("bsfq %1,%0 ; cmovz %2,%0" : "=&r" (val) : "r" (val), "r" (max));
return val;
}
#define find_first_bit(addr,size) \
((__builtin_constant_p(size) && (size) <= BITS_PER_LONG ? \
(__scanbit(*(unsigned long *)addr,(size))) : \
find_first_bit(addr,size)))
#define find_next_bit(addr,size,off) \
((__builtin_constant_p(size) && (size) <= BITS_PER_LONG ? \
((off) + (__scanbit((*(unsigned long *)addr) >> (off),(size)-(off)))) : \
find_next_bit(addr,size,off)))
#define find_first_zero_bit(addr,size) \
((__builtin_constant_p(size) && (size) <= BITS_PER_LONG ? \
(__scanbit(~*(unsigned long *)addr,(size))) : \
find_first_zero_bit(addr,size)))
#define find_next_zero_bit(addr,size,off) \
((__builtin_constant_p(size) && (size) <= BITS_PER_LONG ? \
((off)+(__scanbit(~(((*(unsigned long *)addr)) >> (off)),(size)-(off)))) : \
find_next_zero_bit(addr,size,off)))
/*
* Find string of zero bits in a bitmap. -1 when not found.
*/
extern unsigned long
find_next_zero_string(unsigned long *bitmap, long start, long nbits, int len);
static inline void set_bit_string(unsigned long *bitmap, unsigned long i,
int len)
{
unsigned long end = i + len;
while (i < end) {
__set_bit(i, bitmap);
i++;
}
}
static inline void __clear_bit_string(unsigned long *bitmap, unsigned long i,
int len)
{
unsigned long end = i + len;
while (i < end) {
__clear_bit(i, bitmap);
i++;
}
}
/**
* ffz - find first zero 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__("bsfq %1,%0"
:"=r" (word)
:"r" (~word));
return word;
}
/**
* __ffs - find first 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__("bsfq %1,%0"
:"=r" (word)
:"rm" (word));
return word;
}
/*
* __fls: find last bit set.
* @word: The word to search
*
* Undefined if no zero exists, so code should check against ~0UL first.
*/
static __inline__ unsigned long __fls(unsigned long word)
{
__asm__("bsrq %1,%0"
:"=r" (word)
:"rm" (word));
return word;
}
#ifdef __KERNEL__
#include <asm-generic/bitops/sched.h>
/**
* 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).
*/
static __inline__ int ffs(int x)
{
int r;
__asm__("bsfl %1,%0\n\t"
"cmovzl %2,%0"
: "=r" (r) : "rm" (x), "r" (-1));
return r+1;
}
/**
* fls64 - find last bit set in 64 bit word
* @x: the word to search
*
* This is defined the same way as fls.
*/
static __inline__ int fls64(__u64 x)
{
if (x == 0)
return 0;
return __fls(x) + 1;
}
/**
* fls - find last bit set
* @x: the word to search
*
* This is defined the same way as ffs.
*/
static __inline__ int fls(int x)
{
int r;
__asm__("bsrl %1,%0\n\t"
"cmovzl %2,%0"
: "=&r" (r) : "rm" (x), "rm" (-1));
return r+1;
}
#define ARCH_HAS_FAST_MULTIPLIER 1
#include <asm-generic/bitops/hweight.h>
#endif /* __KERNEL__ */
#ifdef __KERNEL__
#include <asm-generic/bitops/ext2-non-atomic.h>
#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)
#include <asm-generic/bitops/minix.h>
#endif /* __KERNEL__ */
#endif /* _X86_64_BITOPS_H */