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/*
* Copyright 1995, Russell King.
* Various bits and pieces copyrights include:
* Linus Torvalds (test_bit).
*
* bit 0 is the LSB of addr; bit 32 is the LSB of (addr+1).
*
* 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 priviledged
* 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__
/*
* Function prototypes to keep gcc -Wall happy.
*/
extern void set_bit(int nr, volatile void * addr);
extern void clear_bit(int nr, volatile void * addr);
extern void change_bit(int nr, volatile void * addr);
extern int test_and_set_bit(int nr, volatile void * addr);
extern int test_and_clear_bit(int nr, volatile void * addr);
extern int test_and_change_bit(int nr, volatile void * addr);
extern int find_first_zero_bit(void * addr, unsigned size);
extern int find_next_zero_bit(void * addr, int size, int offset);
/*
* This routine doesn't need to be atomic.
*/
extern __inline__ int test_bit(int nr, const void * addr)
{
return ((unsigned char *) addr)[nr >> 3] & (1U << (nr & 7));
}
/*
* ffz = Find First Zero in word. Undefined if no zero exists,
* so code should check against ~0UL first..
*/
extern __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;
}
/*
* 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)
/*
* 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)
#define ext2_set_bit test_and_set_bit
#define ext2_clear_bit test_and_clear_bit
#define ext2_test_bit test_bit
#define ext2_find_first_zero_bit find_first_zero_bit
#define ext2_find_next_zero_bit find_next_zero_bit
/* Bitmap functions for the minix filesystem. */
#define minix_set_bit(nr,addr) test_and_set_bit(nr,addr)
#define minix_clear_bit(nr,addr) test_and_clear_bit(nr,addr)
#define minix_test_bit(nr,addr) test_bit(nr,addr)
#define minix_find_first_zero_bit(addr,size) find_first_zero_bit(addr,size)
#endif /* __KERNEL__ */
#endif /* _ARM_BITOPS_H */
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