165 строки
3.6 KiB
C
165 строки
3.6 KiB
C
#ifndef _I386_BITOPS_H
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#define _I386_BITOPS_H
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/*
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* Copyright 1992, Linus Torvalds.
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*/
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/**
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* find_first_zero_bit - find the first zero bit in a memory region
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* @addr: The address to start the search at
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* @size: The maximum size to search
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*
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* Returns the bit number of the first zero bit, not the number of the byte
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* containing a bit.
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*/
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static inline int find_first_zero_bit(const unsigned long *addr, unsigned size)
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{
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int d0, d1, d2;
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int res;
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if (!size)
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return 0;
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/* This looks at memory. Mark it volatile to tell gcc not to move it around */
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__asm__ __volatile__(
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"movl $-1,%%eax\n\t"
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"xorl %%edx,%%edx\n\t"
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"repe; scasl\n\t"
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"je 1f\n\t"
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"xorl -4(%%edi),%%eax\n\t"
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"subl $4,%%edi\n\t"
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"bsfl %%eax,%%edx\n"
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"1:\tsubl %%ebx,%%edi\n\t"
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"shll $3,%%edi\n\t"
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"addl %%edi,%%edx"
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:"=d" (res), "=&c" (d0), "=&D" (d1), "=&a" (d2)
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:"1" ((size + 31) >> 5), "2" (addr), "b" (addr) : "memory");
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return res;
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}
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/**
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* find_next_zero_bit - find the first zero bit in a memory region
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* @addr: The address to base the search on
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* @offset: The bit number to start searching at
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* @size: The maximum size to search
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*/
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int find_next_zero_bit(const unsigned long *addr, int size, int offset);
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/**
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* __ffs - find first bit in word.
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* @word: The word to search
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*
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* Undefined if no bit exists, so code should check against 0 first.
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*/
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static inline unsigned long __ffs(unsigned long word)
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{
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__asm__("bsfl %1,%0"
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:"=r" (word)
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:"rm" (word));
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return word;
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}
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/**
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* find_first_bit - find the first set bit in a memory region
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* @addr: The address to start the search at
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* @size: The maximum size to search
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*
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* Returns the bit number of the first set bit, not the number of the byte
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* containing a bit.
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*/
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static inline unsigned find_first_bit(const unsigned long *addr, unsigned size)
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{
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unsigned x = 0;
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while (x < size) {
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unsigned long val = *addr++;
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if (val)
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return __ffs(val) + x;
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x += (sizeof(*addr)<<3);
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}
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return x;
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}
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/**
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* find_next_bit - find the first set bit in a memory region
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* @addr: The address to base the search on
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* @offset: The bit number to start searching at
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* @size: The maximum size to search
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*/
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int find_next_bit(const unsigned long *addr, int size, int offset);
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/**
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* ffz - find first zero in word.
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* @word: The word to search
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*
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* Undefined if no zero exists, so code should check against ~0UL first.
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*/
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static inline unsigned long ffz(unsigned long word)
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{
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__asm__("bsfl %1,%0"
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:"=r" (word)
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:"r" (~word));
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return word;
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}
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#ifdef __KERNEL__
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#include <asm-generic/bitops/sched.h>
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/**
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* ffs - find first bit set
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* @x: the word to search
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*
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* This is defined the same way as
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* the libc and compiler builtin ffs routines, therefore
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* differs in spirit from the above ffz() (man ffs).
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*/
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static inline int ffs(int x)
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{
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int r;
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__asm__("bsfl %1,%0\n\t"
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"jnz 1f\n\t"
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"movl $-1,%0\n"
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"1:" : "=r" (r) : "rm" (x));
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return r+1;
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}
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/**
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* fls - find last bit set
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* @x: the word to search
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*
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* This is defined the same way as ffs().
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*/
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static inline int fls(int x)
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{
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int r;
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__asm__("bsrl %1,%0\n\t"
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"jnz 1f\n\t"
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"movl $-1,%0\n"
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"1:" : "=r" (r) : "rm" (x));
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return r+1;
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}
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#include <asm-generic/bitops/hweight.h>
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#endif /* __KERNEL__ */
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#include <asm-generic/bitops/fls64.h>
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#ifdef __KERNEL__
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#include <asm-generic/bitops/ext2-non-atomic.h>
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#define ext2_set_bit_atomic(lock, nr, addr) \
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test_and_set_bit((nr), (unsigned long *)addr)
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#define ext2_clear_bit_atomic(lock, nr, addr) \
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test_and_clear_bit((nr), (unsigned long *)addr)
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#include <asm-generic/bitops/minix.h>
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#endif /* __KERNEL__ */
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#endif /* _I386_BITOPS_H */
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