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Diffstat (limited to 'arch/arm/include/asm/bitops.h')
| -rw-r--r-- | arch/arm/include/asm/bitops.h | 151 |
1 files changed, 151 insertions, 0 deletions
diff --git a/arch/arm/include/asm/bitops.h b/arch/arm/include/asm/bitops.h new file mode 100644 index 000000000..270f163ee --- /dev/null +++ b/arch/arm/include/asm/bitops.h @@ -0,0 +1,151 @@ +/* + * 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__ + +#include <asm/proc/system.h> + +#define smp_mb__before_clear_bit() do { } while (0) +#define smp_mb__after_clear_bit() do { } while (0) + +/* + * 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); + +static inline void __change_bit(int nr, volatile void *addr) +{ + unsigned long mask = BIT_MASK(nr); + unsigned long *p = ((unsigned long *)addr) + BIT_WORD(nr); + + *p ^= mask; +} + +static inline int __test_and_set_bit(int nr, volatile void *addr) +{ + unsigned long mask = BIT_MASK(nr); + unsigned long *p = ((unsigned long *)addr) + BIT_WORD(nr); + unsigned long old = *p; + + *p = old | mask; + return (old & mask) != 0; +} + +static inline int test_and_set_bit(int nr, volatile void * addr) +{ + unsigned long flags; + int out; + + local_irq_save(flags); + out = __test_and_set_bit(nr, addr); + local_irq_restore(flags); + + return out; +} + +static inline int __test_and_clear_bit(int nr, volatile void *addr) +{ + unsigned long mask = BIT_MASK(nr); + unsigned long *p = ((unsigned long *)addr) + BIT_WORD(nr); + unsigned long old = *p; + + *p = old & ~mask; + return (old & mask) != 0; +} + +static inline int test_and_clear_bit(int nr, volatile void * addr) +{ + unsigned long flags; + int out; + + local_irq_save(flags); + out = __test_and_clear_bit(nr, addr); + local_irq_restore(flags); + + return out; +} + +extern int test_and_change_bit(int nr, volatile void * addr); + +static inline int __test_and_change_bit(int nr, volatile void *addr) +{ + unsigned long mask = BIT_MASK(nr); + unsigned long *p = ((unsigned long *)addr) + BIT_WORD(nr); + unsigned long old = *p; + + *p = old ^ mask; + return (old & mask) != 0; +} + +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. + */ +static 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.. + */ +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; +} + +/* + * 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_test_and_set_bit(nr,addr) test_and_set_bit(nr,addr) +#define minix_set_bit(nr,addr) set_bit(nr,addr) +#define minix_test_and_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 */ |