#ifndef _ASM_GENERIC_BITOPS_H_
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#ifndef _ASM_GENERIC_BITOPS_H_
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#define _ASM_GENERIC_BITOPS_H_
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#define _ASM_GENERIC_BITOPS_H_
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#ifdef __KERNEL__
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#ifdef __KERNEL__
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#include <asm/system.h>
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#include <asm/system.h>
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#endif
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#endif
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/*
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/*
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* For the benefit of those who are trying to port Linux to another
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* For the benefit of those who are trying to port Linux to another
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* architecture, here are some C-language equivalents. You should
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* architecture, here are some C-language equivalents. You should
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* recode these in the native assembly language, if at all possible.
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* recode these in the native assembly language, if at all possible.
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* To guarantee atomicity, these routines call cli() and sti() to
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* To guarantee atomicity, these routines call cli() and sti() to
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* disable interrupts while they operate. (You have to provide inline
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* disable interrupts while they operate. (You have to provide inline
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* routines to cli() and sti().)
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* routines to cli() and sti().)
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*
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*
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* Also note, these routines assume that you have 32 bit integers.
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* Also note, these routines assume that you have 32 bit integers.
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* You will have to change this if you are trying to port Linux to the
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* You will have to change this if you are trying to port Linux to the
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* Alpha architecture or to a Cray. :-)
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* Alpha architecture or to a Cray. :-)
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*
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*
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* C language equivalents written by Theodore Ts'o, 9/26/92
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* C language equivalents written by Theodore Ts'o, 9/26/92
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*/
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*/
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extern __inline__ int set_bit(int nr, void * a)
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extern __inline__ int set_bit(int nr, void * a)
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{
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{
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int * addr = a;
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int * addr = a;
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int mask, retval;
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int mask, retval;
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unsigned long flags;
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unsigned long flags;
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addr += nr >> 5;
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addr += nr >> 5;
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mask = 1 << (nr & 0x1f);
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mask = 1 << (nr & 0x1f);
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save_flags(flags); cli();
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save_flags(flags); cli();
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retval = (mask & *addr) != 0;
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retval = (mask & *addr) != 0;
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*addr |= mask;
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*addr |= mask;
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restore_flags(flags);
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restore_flags(flags);
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return retval;
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return retval;
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}
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}
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extern __inline__ int clear_bit(int nr, void * a)
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extern __inline__ int clear_bit(int nr, void * a)
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{
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{
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int * addr = a;
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int * addr = a;
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int mask, retval;
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int mask, retval;
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unsigned long flags;
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unsigned long flags;
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addr += nr >> 5;
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addr += nr >> 5;
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mask = 1 << (nr & 0x1f);
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mask = 1 << (nr & 0x1f);
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save_flags(flags); cli();
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save_flags(flags); cli();
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retval = (mask & *addr) != 0;
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retval = (mask & *addr) != 0;
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*addr &= ~mask;
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*addr &= ~mask;
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restore_flags(flags);
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restore_flags(flags);
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return retval;
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return retval;
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}
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}
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extern __inline__ unsigned long change_bit(unsigned long nr, void *addr)
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extern __inline__ unsigned long change_bit(unsigned long nr, void *addr)
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{
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{
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int mask, flags;
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int mask, flags;
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unsigned long *ADDR = (unsigned long *) addr;
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unsigned long *ADDR = (unsigned long *) addr;
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unsigned long oldbit;
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unsigned long oldbit;
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ADDR += nr >> 5;
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ADDR += nr >> 5;
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mask = 1 << (nr & 31);
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mask = 1 << (nr & 31);
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save_flags(flags); cli();
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save_flags(flags); cli();
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oldbit = (mask & *ADDR);
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oldbit = (mask & *ADDR);
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*ADDR ^= mask;
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*ADDR ^= mask;
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restore_flags(flags);
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restore_flags(flags);
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return oldbit != 0;
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return oldbit != 0;
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}
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}
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extern __inline__ int test_bit(int nr, void * a)
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extern __inline__ int test_bit(int nr, void * a)
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{
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{
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int * addr = a;
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int * addr = a;
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int mask;
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int mask;
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addr += nr >> 5;
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addr += nr >> 5;
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mask = 1 << (nr & 0x1f);
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mask = 1 << (nr & 0x1f);
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return ((mask & *addr) != 0);
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return ((mask & *addr) != 0);
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}
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}
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/* The easy/cheese version for now. */
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/* The easy/cheese version for now. */
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extern __inline__ unsigned long ffz(unsigned long word)
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extern __inline__ unsigned long ffz(unsigned long word)
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{
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{
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unsigned long result = 0;
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unsigned long result = 0;
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while(word & 1) {
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while(word & 1) {
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result++;
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result++;
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word >>= 1;
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word >>= 1;
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}
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}
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return result;
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return result;
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}
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}
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/* find_next_zero_bit() finds the first zero bit in a bit string of length
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/* find_next_zero_bit() finds the first zero bit in a bit string of length
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* 'size' bits, starting the search at bit 'offset'. This is largely based
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* 'size' bits, starting the search at bit 'offset'. This is largely based
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* on Linus's ALPHA routines, which are pretty portable BTW.
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* on Linus's ALPHA routines, which are pretty portable BTW.
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*/
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*/
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extern __inline__ unsigned long find_next_zero_bit(void *addr, unsigned long size, unsigned long offset)
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extern __inline__ unsigned long find_next_zero_bit(void *addr, unsigned long size, unsigned long offset)
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{
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{
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unsigned long *p = ((unsigned long *) addr) + (offset >> 5);
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unsigned long *p = ((unsigned long *) addr) + (offset >> 5);
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unsigned long result = offset & ~31UL;
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unsigned long result = offset & ~31UL;
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unsigned long tmp;
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unsigned long tmp;
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if (offset >= size)
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if (offset >= size)
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return size;
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return size;
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size -= result;
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size -= result;
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offset &= 31UL;
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offset &= 31UL;
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if (offset) {
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if (offset) {
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tmp = *(p++);
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tmp = *(p++);
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tmp |= ~0UL >> (32-offset);
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tmp |= ~0UL >> (32-offset);
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if (size < 32)
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if (size < 32)
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goto found_first;
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goto found_first;
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if (~tmp)
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if (~tmp)
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goto found_middle;
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goto found_middle;
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size -= 32;
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size -= 32;
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result += 32;
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result += 32;
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}
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}
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while (size & ~31UL) {
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while (size & ~31UL) {
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if (~(tmp = *(p++)))
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if (~(tmp = *(p++)))
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goto found_middle;
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goto found_middle;
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result += 32;
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result += 32;
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size -= 32;
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size -= 32;
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}
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}
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if (!size)
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if (!size)
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return result;
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return result;
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tmp = *p;
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tmp = *p;
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found_first:
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found_first:
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tmp |= ~0UL >> size;
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tmp |= ~0UL >> size;
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found_middle:
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found_middle:
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return result + ffz(tmp);
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return result + ffz(tmp);
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}
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}
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/* Linus sez that gcc can optimize the following correctly, we'll see if this
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/* Linus sez that gcc can optimize the following correctly, we'll see if this
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* holds on the Sparc as it does for the ALPHA.
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* holds on the Sparc as it does for the ALPHA.
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*/
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*/
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#define find_first_zero_bit(addr, size) \
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#define find_first_zero_bit(addr, size) \
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find_next_zero_bit((addr), (size), 0)
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find_next_zero_bit((addr), (size), 0)
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/* Now for the ext2 filesystem bit operations and helper routines. */
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/* Now for the ext2 filesystem bit operations and helper routines. */
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extern __inline__ int ext2_set_bit(int nr,void * addr)
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extern __inline__ int ext2_set_bit(int nr,void * addr)
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{
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{
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int mask, retval, flags;
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int mask, retval, flags;
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unsigned char *ADDR = (unsigned char *) addr;
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unsigned char *ADDR = (unsigned char *) addr;
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ADDR += nr >> 3;
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ADDR += nr >> 3;
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mask = 1 << (nr & 0x07);
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mask = 1 << (nr & 0x07);
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save_flags(flags); cli();
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save_flags(flags); cli();
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retval = (mask & *ADDR) != 0;
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retval = (mask & *ADDR) != 0;
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*ADDR |= mask;
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*ADDR |= mask;
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restore_flags(flags);
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restore_flags(flags);
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return retval;
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return retval;
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}
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}
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extern __inline__ int ext2_clear_bit(int nr, void * addr)
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extern __inline__ int ext2_clear_bit(int nr, void * addr)
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{
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{
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int mask, retval, flags;
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int mask, retval, flags;
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unsigned char *ADDR = (unsigned char *) addr;
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unsigned char *ADDR = (unsigned char *) addr;
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ADDR += nr >> 3;
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ADDR += nr >> 3;
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mask = 1 << (nr & 0x07);
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mask = 1 << (nr & 0x07);
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save_flags(flags); cli();
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save_flags(flags); cli();
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retval = (mask & *ADDR) != 0;
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retval = (mask & *ADDR) != 0;
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*ADDR &= ~mask;
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*ADDR &= ~mask;
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restore_flags(flags);
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restore_flags(flags);
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return retval;
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return retval;
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}
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}
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extern __inline__ int ext2_test_bit(int nr, const void * addr)
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extern __inline__ int ext2_test_bit(int nr, const void * addr)
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{
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{
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int mask;
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int mask;
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const unsigned char *ADDR = (const unsigned char *) addr;
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const unsigned char *ADDR = (const unsigned char *) addr;
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ADDR += nr >> 3;
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ADDR += nr >> 3;
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mask = 1 << (nr & 0x07);
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mask = 1 << (nr & 0x07);
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return ((mask & *ADDR) != 0);
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return ((mask & *ADDR) != 0);
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}
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}
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#define ext2_find_first_zero_bit(addr, size) \
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#define ext2_find_first_zero_bit(addr, size) \
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ext2_find_next_zero_bit((addr), (size), 0)
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ext2_find_next_zero_bit((addr), (size), 0)
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extern __inline__ unsigned long ext2_find_next_zero_bit(void *addr, unsigned long size, unsigned long offset)
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extern __inline__ unsigned long ext2_find_next_zero_bit(void *addr, unsigned long size, unsigned long offset)
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{
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{
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unsigned long *p = ((unsigned long *) addr) + (offset >> 5);
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unsigned long *p = ((unsigned long *) addr) + (offset >> 5);
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unsigned long result = offset & ~31UL;
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unsigned long result = offset & ~31UL;
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unsigned long tmp;
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unsigned long tmp;
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if (offset >= size)
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if (offset >= size)
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return size;
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return size;
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size -= result;
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size -= result;
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offset &= 31UL;
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offset &= 31UL;
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if(offset) {
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if(offset) {
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tmp = *(p++);
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tmp = *(p++);
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tmp |= ~0UL << (32-offset);
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tmp |= ~0UL << (32-offset);
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if(size < 32)
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if(size < 32)
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goto found_first;
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goto found_first;
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if(~tmp)
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if(~tmp)
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goto found_middle;
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goto found_middle;
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size -= 32;
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size -= 32;
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result += 32;
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result += 32;
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}
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}
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while(size & ~31UL) {
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while(size & ~31UL) {
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if(~(tmp = *(p++)))
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if(~(tmp = *(p++)))
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goto found_middle;
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goto found_middle;
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result += 32;
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result += 32;
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size -= 32;
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size -= 32;
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}
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}
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if(!size)
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if(!size)
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return result;
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return result;
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tmp = *p;
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tmp = *p;
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found_first:
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found_first:
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tmp |= ~0UL << size;
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tmp |= ~0UL << size;
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found_middle:
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found_middle:
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tmp = ((tmp>>24) | ((tmp>>8)&0xff00) | ((tmp<<8)&0xff0000) | (tmp<<24));
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tmp = ((tmp>>24) | ((tmp>>8)&0xff00) | ((tmp<<8)&0xff0000) | (tmp<<24));
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return result + ffz(tmp);
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return result + ffz(tmp);
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}
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}
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#define __ext2_set_bit ext2_set_bit
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#define __ext2_set_bit ext2_set_bit
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#define __ext2_clear_bit ext2_clear_bit
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#define __ext2_clear_bit ext2_clear_bit
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extern __inline__ int __ext2_test_bit(int nr, __const__ void * addr)
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extern __inline__ int __ext2_test_bit(int nr, __const__ void * addr)
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{
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{
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int mask;
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int mask;
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__const__ unsigned char *ADDR = (__const__ unsigned char *) addr;
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__const__ unsigned char *ADDR = (__const__ unsigned char *) addr;
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ADDR += nr >> 3;
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ADDR += nr >> 3;
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mask = 1 << (nr & 0x07);
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mask = 1 << (nr & 0x07);
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return ((mask & *ADDR) != 0);
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return ((mask & *ADDR) != 0);
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}
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}
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extern __inline__ unsigned short __swab16(unsigned short value)
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extern __inline__ unsigned short __swab16(unsigned short value)
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{
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{
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return ((value >> 8) | (value << 8));
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return ((value >> 8) | (value << 8));
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}
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}
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extern __inline__ unsigned long __swab32(unsigned long value)
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extern __inline__ unsigned long __swab32(unsigned long value)
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{
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{
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return ((value >> 24) | ((value >> 8) & 0xff00) |
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return ((value >> 24) | ((value >> 8) & 0xff00) |
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((value << 8) & 0xff0000) | (value << 24));
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((value << 8) & 0xff0000) | (value << 24));
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}
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}
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#define __ext2_find_first_zero_bit(addr, size) \
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#define __ext2_find_first_zero_bit(addr, size) \
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__ext2_find_next_zero_bit((addr), (size), 0)
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__ext2_find_next_zero_bit((addr), (size), 0)
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extern __inline__ unsigned long __ext2_find_next_zero_bit(void *addr, unsigned long size, unsigned long offset)
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extern __inline__ unsigned long __ext2_find_next_zero_bit(void *addr, unsigned long size, unsigned long offset)
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{
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{
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unsigned long *p = ((unsigned long *) addr) + (offset >> 5);
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unsigned long *p = ((unsigned long *) addr) + (offset >> 5);
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unsigned long result = offset & ~31UL;
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unsigned long result = offset & ~31UL;
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unsigned long tmp;
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unsigned long tmp;
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if (offset >= size)
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if (offset >= size)
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return size;
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return size;
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size -= result;
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size -= result;
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offset &= 31UL;
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offset &= 31UL;
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if(offset) {
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if(offset) {
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tmp = *(p++);
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tmp = *(p++);
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tmp |= __swab32(~0UL >> (32-offset));
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tmp |= __swab32(~0UL >> (32-offset));
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if(size < 32)
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if(size < 32)
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goto found_first;
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goto found_first;
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if(~tmp)
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if(~tmp)
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goto found_middle;
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goto found_middle;
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size -= 32;
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size -= 32;
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result += 32;
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result += 32;
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}
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}
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while(size & ~31UL) {
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while(size & ~31UL) {
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if(~(tmp = *(p++)))
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if(~(tmp = *(p++)))
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goto found_middle;
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goto found_middle;
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result += 32;
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result += 32;
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size -= 32;
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size -= 32;
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}
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}
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if(!size)
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if(!size)
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return result;
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return result;
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tmp = *p;
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tmp = *p;
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found_first:
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found_first:
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return result + ffz(__swab32(tmp) | (~0UL << size));
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return result + ffz(__swab32(tmp) | (~0UL << size));
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found_middle:
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found_middle:
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return result + ffz(__swab32(tmp));
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return result + ffz(__swab32(tmp));
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}
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}
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#endif /* _ASM_GENERIC_BITOPS_H */
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#endif /* _ASM_GENERIC_BITOPS_H */
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