WSL2-Linux-Kernel/include/asm-x86_64/bitops.h

416 строки
10 KiB
C

#ifndef _X86_64_BITOPS_H
#define _X86_64_BITOPS_H
/*
* Copyright 1992, Linus Torvalds.
*/
#include <linux/config.h>
#ifdef CONFIG_SMP
#define LOCK_PREFIX "lock ; "
#else
#define LOCK_PREFIX ""
#endif
#define ADDR (*(volatile long *) addr)
/**
* 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"
:"=m" (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"
:"=m" (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"
:"=m" (ADDR)
:"dIr" (nr));
}
static __inline__ void __clear_bit(int nr, volatile void * addr)
{
__asm__ __volatile__(
"btrl %1,%0"
:"=m" (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"
:"=m" (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"
:"=m" (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),"=m" (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),"=m" (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),"=m" (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),"=m" (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),"=m" (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),"=m" (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" (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;
}
#ifdef __KERNEL__
static inline int sched_find_first_bit(const unsigned long *b)
{
if (b[0])
return __ffs(b[0]);
if (b[1])
return __ffs(b[1]) + 64;
return __ffs(b[2]) + 128;
}
/**
* 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;
}
/**
* hweightN - returns the hamming weight of a N-bit word
* @x: the word to weigh
*
* The Hamming Weight of a number is the total number of bits set in it.
*/
#define hweight64(x) generic_hweight64(x)
#define hweight32(x) generic_hweight32(x)
#define hweight16(x) generic_hweight16(x)
#define hweight8(x) generic_hweight8(x)
#endif /* __KERNEL__ */
#ifdef __KERNEL__
#define ext2_set_bit(nr,addr) \
__test_and_set_bit((nr),(unsigned long*)addr)
#define ext2_set_bit_atomic(lock,nr,addr) \
test_and_set_bit((nr),(unsigned long*)addr)
#define ext2_clear_bit(nr, addr) \
__test_and_clear_bit((nr),(unsigned long*)addr)
#define ext2_clear_bit_atomic(lock,nr,addr) \
test_and_clear_bit((nr),(unsigned long*)addr)
#define ext2_test_bit(nr, addr) test_bit((nr),(unsigned long*)addr)
#define ext2_find_first_zero_bit(addr, size) \
find_first_zero_bit((unsigned long*)addr, size)
#define ext2_find_next_zero_bit(addr, size, off) \
find_next_zero_bit((unsigned long*)addr, size, off)
/* Bitmap functions for the minix filesystem. */
#define minix_test_and_set_bit(nr,addr) __test_and_set_bit(nr,(void*)addr)
#define minix_set_bit(nr,addr) __set_bit(nr,(void*)addr)
#define minix_test_and_clear_bit(nr,addr) __test_and_clear_bit(nr,(void*)addr)
#define minix_test_bit(nr,addr) test_bit(nr,(void*)addr)
#define minix_find_first_zero_bit(addr,size) \
find_first_zero_bit((void*)addr,size)
/* find last set bit */
#define fls(x) generic_fls(x)
#endif /* __KERNEL__ */
#endif /* _X86_64_BITOPS_H */