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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__
- #include <asm/proc-armv/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 = 0;
- 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 = 0;
- 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;
- }
- /*
- * 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));
- }
- static inline int __ilog2(unsigned int x)
- {
- return generic_fls(x) - 1;
- }
- /*
- * 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;
- }
- static inline int find_next_zero_bit(void *addr, int size, int offset)
- {
- unsigned long *p = ((unsigned long *)addr) + (offset >> 5);
- unsigned long result = offset & ~31UL;
- unsigned long tmp;
- if (offset >= size)
- return size;
- size -= result;
- offset &= 31UL;
- if (offset) {
- tmp = *(p++);
- tmp |= ~0UL >> (32-offset);
- if (size < 32)
- goto found_first;
- if (~tmp)
- goto found_middle;
- size -= 32;
- result += 32;
- }
- while (size & ~31UL) {
- tmp = *(p++);
- if (~tmp)
- goto found_middle;
- result += 32;
- size -= 32;
- }
- if (!size)
- return result;
- tmp = *p;
- found_first:
- tmp |= ~0UL >> size;
- found_middle:
- return result + ffz(tmp);
- }
- /*
- * 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 find_first_zero_bit(addr, size) \
- find_next_zero_bit((addr), (size), 0)
- #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__ */
- #include <asm-generic/bitops/__fls.h>
- #include <asm-generic/bitops/__ffs.h>
- #include <asm-generic/bitops/fls.h>
- #include <asm-generic/bitops/fls64.h>
- #endif /* _ARM_BITOPS_H */
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