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DEFINITIONS
This source file includes following definitions.
- __clear_bit
- test_bit
- __change_bit
- __test_and_change_bit
- __ffs
- __ilog2_u32
- fls
- ffs
/* MN10300 bit operations
*
* Copyright (C) 2007 Red Hat, Inc. All Rights Reserved.
* Written by David Howells (dhowells@redhat.com)
*
* This program is free software; you can redistribute it and/or
* modify it under the terms of the GNU General Public Licence
* as published by the Free Software Foundation; either version
* 2 of the Licence, or (at your option) any later version.
*
* 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).
*/
#ifndef __ASM_BITOPS_H
#define __ASM_BITOPS_H
#include <asm/cpu-regs.h>
#define smp_mb__before_clear_bit() barrier()
#define smp_mb__after_clear_bit() barrier()
/*
* set bit
*/
#define __set_bit(nr, addr) \
({ \
volatile unsigned char *_a = (unsigned char *)(addr); \
const unsigned shift = (nr) & 7; \
_a += (nr) >> 3; \
\
asm volatile("bset %2,(%1) # set_bit reg" \
: "=m"(*_a) \
: "a"(_a), "d"(1 << shift), "m"(*_a) \
: "memory", "cc"); \
})
#define set_bit(nr, addr) __set_bit((nr), (addr))
/*
* clear bit
*/
#define ___clear_bit(nr, addr) \
({ \
volatile unsigned char *_a = (unsigned char *)(addr); \
const unsigned shift = (nr) & 7; \
_a += (nr) >> 3; \
\
asm volatile("bclr %2,(%1) # clear_bit reg" \
: "=m"(*_a) \
: "a"(_a), "d"(1 << shift), "m"(*_a) \
: "memory", "cc"); \
})
#define clear_bit(nr, addr) ___clear_bit((nr), (addr))
static inline void __clear_bit(int nr, volatile void *addr)
{
unsigned int *a = (unsigned int *) addr;
int mask;
a += nr >> 5;
mask = 1 << (nr & 0x1f);
*a &= ~mask;
}
/*
* test bit
*/
static inline int test_bit(int nr, const volatile void *addr)
{
return 1UL & (((const unsigned int *) addr)[nr >> 5] >> (nr & 31));
}
/*
* change bit
*/
static inline void __change_bit(int nr, volatile void *addr)
{
int mask;
unsigned int *a = (unsigned int *) addr;
a += nr >> 5;
mask = 1 << (nr & 0x1f);
*a ^= mask;
}
extern void change_bit(int nr, volatile void *addr);
/*
* test and set bit
*/
#define __test_and_set_bit(nr,addr) \
({ \
volatile unsigned char *_a = (unsigned char *)(addr); \
const unsigned shift = (nr) & 7; \
unsigned epsw; \
_a += (nr) >> 3; \
\
asm volatile("bset %3,(%2) # test_set_bit reg\n" \
"mov epsw,%1" \
: "=m"(*_a), "=d"(epsw) \
: "a"(_a), "d"(1 << shift), "m"(*_a) \
: "memory", "cc"); \
\
!(epsw & EPSW_FLAG_Z); \
})
#define test_and_set_bit(nr, addr) __test_and_set_bit((nr), (addr))
/*
* test and clear bit
*/
#define __test_and_clear_bit(nr, addr) \
({ \
volatile unsigned char *_a = (unsigned char *)(addr); \
const unsigned shift = (nr) & 7; \
unsigned epsw; \
_a += (nr) >> 3; \
\
asm volatile("bclr %3,(%2) # test_clear_bit reg\n" \
"mov epsw,%1" \
: "=m"(*_a), "=d"(epsw) \
: "a"(_a), "d"(1 << shift), "m"(*_a) \
: "memory", "cc"); \
\
!(epsw & EPSW_FLAG_Z); \
})
#define test_and_clear_bit(nr, addr) __test_and_clear_bit((nr), (addr))
/*
* test and change bit
*/
static inline int __test_and_change_bit(int nr, volatile void *addr)
{
int mask, retval;
unsigned int *a = (unsigned int *)addr;
a += nr >> 5;
mask = 1 << (nr & 0x1f);
retval = (mask & *a) != 0;
*a ^= mask;
return retval;
}
extern int test_and_change_bit(int nr, volatile void *addr);
#include <asm-generic/bitops/lock.h>
#ifdef __KERNEL__
/**
* __ffs - find first bit set
* @x: the word to search
*
* - return 31..0 to indicate bit 31..0 most least significant bit set
* - if no bits are set in x, the result is undefined
*/
static inline __attribute__((const))
unsigned long __ffs(unsigned long x)
{
int bit;
asm("bsch %2,%0" : "=r"(bit) : "0"(0), "r"(x & -x));
return bit;
}
/*
* special slimline version of fls() for calculating ilog2_u32()
* - note: no protection against n == 0
*/
static inline __attribute__((const))
int __ilog2_u32(u32 n)
{
int bit;
asm("bsch %2,%0" : "=r"(bit) : "0"(0), "r"(n));
return bit;
}
/**
* fls - find last bit set
* @x: the word to search
*
* This is defined the same way as ffs:
* - return 32..1 to indicate bit 31..0 most significant bit set
* - return 0 to indicate no bits set
*/
static inline __attribute__((const))
int fls(int x)
{
return (x != 0) ? __ilog2_u32(x) + 1 : 0;
}
/**
* ffs - find first bit set
* @x: the word to search
*
* - return 32..1 to indicate bit 31..0 most least significant bit set
* - return 0 to indicate no bits set
*/
static inline __attribute__((const))
int ffs(int x)
{
/* Note: (x & -x) gives us a mask that is the least significant
* (rightmost) 1-bit of the value in x.
*/
return fls(x & -x);
}
#include <asm-generic/bitops/ffz.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>
#define ext2_set_bit_atomic(lock, nr, addr) \
test_and_set_bit((nr) ^ 0x18, (addr))
#define ext2_clear_bit_atomic(lock, nr, addr) \
test_and_clear_bit((nr) ^ 0x18, (addr))
#include <asm-generic/bitops/ext2-non-atomic.h>
#include <asm-generic/bitops/minix-le.h>
#endif /* __KERNEL__ */
#endif /* __ASM_BITOPS_H */