/* * 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 */