148817ba09
The majority of architectures implement ext2 atomic bitops as
test_and_{set,clear}_bit() without spinlock.
This adds this type of generic implementation in ext2-atomic-setbit.h and
use it wherever possible.
Signed-off-by: Akinobu Mita <akinobu.mita@gmail.com>
Suggested-by: Andreas Dilger <adilger@dilger.ca>
Suggested-by: Arnd Bergmann <arnd@arndb.de>
Acked-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
234 lines
5.5 KiB
C
234 lines
5.5 KiB
C
/* 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(unsigned long 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(unsigned long nr, const volatile void *addr)
|
|
{
|
|
return 1UL & (((const volatile unsigned int *) addr)[nr >> 5] >> (nr & 31));
|
|
}
|
|
|
|
/*
|
|
* change bit
|
|
*/
|
|
static inline void __change_bit(unsigned long 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(unsigned long 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(unsigned long 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(unsigned long 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) : "cc");
|
|
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) : "cc");
|
|
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;
|
|
}
|
|
|
|
/**
|
|
* __fls - find last (most-significant) set bit in a long 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)
|
|
{
|
|
return __ilog2_u32(word);
|
|
}
|
|
|
|
/**
|
|
* 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>
|
|
#include <asm-generic/bitops/ext2-atomic-setbit.h>
|
|
#include <asm-generic/bitops/le.h>
|
|
|
|
#endif /* __KERNEL__ */
|
|
#endif /* __ASM_BITOPS_H */
|