/*
* Copyright 1995, Russell King.
*
* Based on the arm32 version by RMK (and others). Their copyrights apply to
* Those parts.
* Modified for arm26 by Ian Molton on 25/11/04
*
* bit 0 is the LSB of an "unsigned long" quantity.
*
* Please note that the code in this file should never be included
* from user space. Many of these are not implemented in assembler
* since they would be too costly. Also, they require privileged
* instructions (which are not available from user mode) to ensure
* that they are atomic.
*/
#ifndef __ASM_ARM_BITOPS_H
#define __ASM_ARM_BITOPS_H
#ifdef __KERNEL__
#include <linux/compiler.h>
#include <asm/system.h>
#define smp_mb__before_clear_bit() do { } while (0)
#define smp_mb__after_clear_bit() do { } while (0)
/*
* These functions are the basis of our bit ops.
*
* First, the atomic bitops. These use native endian.
*/
static inline void ____atomic_set_bit(unsigned int bit, volatile unsigned long *p)
{
unsigned long flags;
unsigned long mask = 1UL << (bit & 31);
p += bit >> 5;
local_irq_save(flags);
*p |= mask;
local_irq_restore(flags);
}
static inline void ____atomic_clear_bit(unsigned int bit, volatile unsigned long *p)
{
unsigned long flags;
unsigned long mask = 1UL << (bit & 31);
p += bit >> 5;
local_irq_save(flags);
*p &= ~mask;
local_irq_restore(flags);
}
static inline void ____atomic_change_bit(unsigned int bit, volatile unsigned long *p)
{
unsigned long flags;
unsigned long mask = 1UL << (bit & 31);
p += bit >> 5;
local_irq_save(flags);
*p ^= mask;
local_irq_restore(flags);
}
static inline int
____atomic_test_and_set_bit(unsigned int bit, volatile unsigned long *p)
{
unsigned long flags;
unsigned int res;
unsigned long mask = 1UL << (bit & 31);
p += bit >> 5;
local_irq_save(flags);
res = *p;
*p = res | mask;
local_irq_restore(flags);
return res & mask;
}
static inline int
____atomic_test_and_clear_bit(unsigned int bit, volatile unsigned long *p)
{
unsigned long flags;
unsigned int res;
unsigned long mask = 1UL << (bit & 31);
p += bit >> 5;
local_irq_save(flags);
res = *p;
*p = res & ~mask;
local_irq_restore(flags);
return res & mask;
}
static inline int
____atomic_test_and_change_bit(unsigned int bit, volatile unsigned long *p)
{
unsigned long flags;
unsigned int res;
unsigned long mask = 1UL << (bit & 31);
p += bit >> 5;
local_irq_save(flags);
res = *p;
*p = res ^ mask;
local_irq_restore(flags);
return res & mask;
}
/*
* Now the non-atomic variants. We let the compiler handle all
* optimisations for these. These are all _native_ endian.
*/
static inline void __set_bit(int nr, volatile unsigned long *p)
{
p[nr >> 5] |= (1UL << (nr & 31));
}
static inline void __clear_bit(int nr, volatile unsigned long *p)
{
p[nr >> 5] &= ~(1UL << (nr & 31));
}
static inline void __change_bit(int nr, volatile unsigned long *p)
{
p[nr >> 5] ^= (1UL << (nr & 31));
}
static inline int __test_and_set_bit(int nr, volatile unsigned long *p)
{
unsigned long oldval, mask = 1UL << (nr & 31);
p += nr >> 5;
oldval = *p;
*p = oldval | mask;
return oldval & mask;
}
static inline int __test_and_clear_bit(int nr, volatile unsigned long *p)
{
unsigned long oldval, mask = 1UL << (nr & 31);
p += nr >> 5;
oldval = *p;
*p = oldval & ~mask;
return oldval & mask;
}
static inline int __test_and_change_bit(int nr, volatile unsigned long *p)
{
unsigned long oldval, mask = 1UL << (nr & 31);
p += nr >> 5;
oldval = *p;
*p = oldval ^ mask;
return oldval & mask;
}
/*
* This routine doesn't need to be atomic.
*/
static inline int __test_bit(int nr, const volatile unsigned long * p)
{
return (p[nr >> 5] >> (nr & 31)) & 1UL;
}
/*
* Little endian assembly bitops. nr = 0 -> byte 0 bit 0.
*/
extern void _set_bit_le(int nr, volatile unsigned long * p);
extern void _clear_bit_le(int nr, volatile unsigned long * p);
extern void _change_bit_le(int nr, volatile unsigned long * p);
extern int _test_and_set_bit_le(int nr, volatile unsigned long * p);
extern int _test_and_clear_bit_le(int nr, volatile unsigned long * p);
extern int _test_and_change_bit_le(int nr, volatile unsigned long * p);
extern int _find_first_zero_bit_le(const unsigned long * p, unsigned size);
extern int _find_next_zero_bit_le(void * p, int size, int offset);
extern int _find_first_bit_le(const unsigned long *p, unsigned size);
extern int _find_next_bit_le(const unsigned long *p, int size, int offset);
/*
* The __* form of bitops are non-atomic and may be reordered.
*/
#define ATOMIC_BITOP_LE(name,nr,p) \
(__builtin_constant_p(nr) ? \
____atomic_##name(nr, p) : \
_##name##_le(nr,p))
#define NONATOMIC_BITOP(name,nr,p) \
(____nonatomic_##name(nr, p))
/*
* These are the little endian, atomic definitions.
*/
#define set_bit(nr,p) ATOMIC_BITOP_LE(set_bit,nr,p)
#define clear_bit(nr,p) ATOMIC_BITOP_LE(clear_bit,nr,p)
#define change_bit(nr,p) ATOMIC_BITOP_LE(change_bit,nr,p)
#define test_and_set_bit(nr,p) ATOMIC_BITOP_LE(test_and_set_bit,nr,p)
#define test_and_clear_bit(nr,p) ATOMIC_BITOP_LE(test_and_clear_bit,nr,p)
#define test_and_change_bit(nr,p) ATOMIC_BITOP_LE(test_and_change_bit,nr,p)
#define test_bit(nr,p) __test_bit(nr,p)
#define find_first_zero_bit(p,sz) _find_first_zero_bit_le(p,sz)
#define find_next_zero_bit(p,sz,off) _find_next_zero_bit_le(p,sz,off)
#define find_first_bit(p,sz) _find_first_bit_le(p,sz)
#define find_next_bit(p,sz,off) _find_next_bit_le(p,sz,off)
#define WORD_BITOFF_TO_LE(x) ((x))
/*
* ffz = Find First Zero in word. Undefined if no zero exists,
* so code should check against ~0UL first..
*/
static inline unsigned long ffz(unsigned long word)
{
int k;
word = ~word;
k = 31;
if (word & 0x0000ffff) { k -= 16; word <<= 16; }
if (word & 0x00ff0000) { k -= 8; word <<= 8; }
if (word & 0x0f000000) { k -= 4; word <<= 4; }
if (word & 0x30000000) { k -= 2; word <<= 2; }
if (word & 0x40000000) { k -= 1; }
return k;
}
/*
* ffz = Find First Zero in word. Undefined if no zero exists,
* so code should check against ~0UL first..
*/
static inline unsigned long __ffs(unsigned long word)
{
int k;
k = 31;
if (word & 0x0000ffff) { k -= 16; word <<= 16; }
if (word & 0x00ff0000) { k -= 8; word <<= 8; }
if (word & 0x0f000000) { k -= 4; word <<= 4; }
if (word & 0x30000000) { k -= 2; word <<= 2; }
if (word & 0x40000000) { k -= 1; }
return k;
}
/*
* fls: find last bit set.
*/
#define fls(x) generic_fls(x)
#define fls64(x) generic_fls64(x)
/*
* ffs: find first bit set. This is defined the same way as
* the libc and compiler builtin ffs routines, therefore
* differs in spirit from the above ffz (man ffs).
*/
#define ffs(x) generic_ffs(x)
/*
* Find first bit set in a 168-bit bitmap, where the first
* 128 bits are unlikely to be set.
*/
static inline int sched_find_first_bit(unsigned long *b)
{
unsigned long v;
unsigned int off;
for (off = 0; v = b[off], off < 4; off++) {
if (unlikely(v))
break;
}
return __ffs(v) + off * 32;
}
/*
* hweightN: returns the hamming weight (i.e. the number
* of bits set) of a N-bit word
*/
#define hweight32(x) generic_hweight32(x)
#define hweight16(x) generic_hweight16(x)
#define hweight8(x) generic_hweight8(x)
/*
* Ext2 is defined to use little-endian byte ordering.
* These do not need to be atomic.
*/
#define ext2_set_bit(nr,p) \
__test_and_set_bit(WORD_BITOFF_TO_LE(nr), (unsigned long *)(p))
#define ext2_set_bit_atomic(lock,nr,p) \
test_and_set_bit(WORD_BITOFF_TO_LE(nr), (unsigned long *)(p))
#define ext2_clear_bit(nr,p) \
__test_and_clear_bit(WORD_BITOFF_TO_LE(nr), (unsigned long *)(p))
#define ext2_clear_bit_atomic(lock,nr,p) \
test_and_clear_bit(WORD_BITOFF_TO_LE(nr), (unsigned long *)(p))
#define ext2_test_bit(nr,p) \
__test_bit(WORD_BITOFF_TO_LE(nr), (unsigned long *)(p))
#define ext2_find_first_zero_bit(p,sz) \
_find_first_zero_bit_le(p,sz)
#define ext2_find_next_zero_bit(p,sz,off) \
_find_next_zero_bit_le(p,sz,off)
/*
* Minix is defined to use little-endian byte ordering.
* These do not need to be atomic.
*/
#define minix_set_bit(nr,p) \
__set_bit(WORD_BITOFF_TO_LE(nr), (unsigned long *)(p))
#define minix_test_bit(nr,p) \
__test_bit(WORD_BITOFF_TO_LE(nr), (unsigned long *)(p))
#define minix_test_and_set_bit(nr,p) \
__test_and_set_bit(WORD_BITOFF_TO_LE(nr), (unsigned long *)(p))
#define minix_test_and_clear_bit(nr,p) \
__test_and_clear_bit(WORD_BITOFF_TO_LE(nr), (unsigned long *)(p))
#define minix_find_first_zero_bit(p,sz) \
_find_first_zero_bit_le((unsigned long *)(p),sz)
#endif /* __KERNEL__ */
#endif /* _ARM_BITOPS_H */
