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https://mirrors.bfsu.edu.cn/git/linux.git
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1da177e4c3
Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
342 lines
7.7 KiB
C
342 lines
7.7 KiB
C
/* bitops.h: bit operations for the Fujitsu FR-V CPUs
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*
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* For an explanation of how atomic ops work in this arch, see:
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* Documentation/fujitsu/frv/atomic-ops.txt
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*
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* Copyright (C) 2004 Red Hat, Inc. All Rights Reserved.
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* Written by David Howells (dhowells@redhat.com)
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*
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* This program is free software; you can redistribute it and/or
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* modify it under the terms of the GNU General Public License
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* as published by the Free Software Foundation; either version
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* 2 of the License, or (at your option) any later version.
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*/
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#ifndef _ASM_BITOPS_H
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#define _ASM_BITOPS_H
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#include <linux/config.h>
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#include <linux/compiler.h>
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#include <asm/byteorder.h>
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#include <asm/system.h>
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#include <asm/atomic.h>
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#ifdef __KERNEL__
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/*
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* ffz = Find First Zero in word. Undefined if no zero exists,
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* 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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unsigned long result = 0;
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while (word & 1) {
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result++;
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word >>= 1;
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}
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return result;
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}
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/*
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* clear_bit() doesn't provide any barrier for the compiler.
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*/
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#define smp_mb__before_clear_bit() barrier()
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#define smp_mb__after_clear_bit() barrier()
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static inline int test_and_clear_bit(int nr, volatile void *addr)
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{
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volatile unsigned long *ptr = addr;
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unsigned long mask = 1UL << (nr & 31);
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ptr += nr >> 5;
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return (atomic_test_and_ANDNOT_mask(mask, ptr) & mask) != 0;
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}
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static inline int test_and_set_bit(int nr, volatile void *addr)
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{
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volatile unsigned long *ptr = addr;
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unsigned long mask = 1UL << (nr & 31);
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ptr += nr >> 5;
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return (atomic_test_and_OR_mask(mask, ptr) & mask) != 0;
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}
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static inline int test_and_change_bit(int nr, volatile void *addr)
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{
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volatile unsigned long *ptr = addr;
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unsigned long mask = 1UL << (nr & 31);
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ptr += nr >> 5;
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return (atomic_test_and_XOR_mask(mask, ptr) & mask) != 0;
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}
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static inline void clear_bit(int nr, volatile void *addr)
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{
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test_and_clear_bit(nr, addr);
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}
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static inline void set_bit(int nr, volatile void *addr)
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{
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test_and_set_bit(nr, addr);
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}
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static inline void change_bit(int nr, volatile void * addr)
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{
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test_and_change_bit(nr, addr);
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}
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static inline void __clear_bit(int nr, volatile void * addr)
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{
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volatile unsigned long *a = addr;
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int mask;
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a += nr >> 5;
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mask = 1 << (nr & 31);
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*a &= ~mask;
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}
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static inline void __set_bit(int nr, volatile void * addr)
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{
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volatile unsigned long *a = addr;
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int mask;
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a += nr >> 5;
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mask = 1 << (nr & 31);
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*a |= mask;
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}
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static inline void __change_bit(int nr, volatile void *addr)
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{
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volatile unsigned long *a = addr;
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int mask;
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a += nr >> 5;
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mask = 1 << (nr & 31);
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*a ^= mask;
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}
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static inline int __test_and_clear_bit(int nr, volatile void * addr)
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{
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volatile unsigned long *a = addr;
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int mask, retval;
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a += nr >> 5;
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mask = 1 << (nr & 31);
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retval = (mask & *a) != 0;
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*a &= ~mask;
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return retval;
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}
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static inline int __test_and_set_bit(int nr, volatile void * addr)
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{
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volatile unsigned long *a = addr;
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int mask, retval;
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a += nr >> 5;
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mask = 1 << (nr & 31);
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retval = (mask & *a) != 0;
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*a |= mask;
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return retval;
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}
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static inline int __test_and_change_bit(int nr, volatile void * addr)
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{
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volatile unsigned long *a = addr;
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int mask, retval;
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a += nr >> 5;
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mask = 1 << (nr & 31);
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retval = (mask & *a) != 0;
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*a ^= mask;
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return retval;
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}
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/*
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* This routine doesn't need to be atomic.
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*/
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static inline int __constant_test_bit(int nr, const volatile void * addr)
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{
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return ((1UL << (nr & 31)) & (((const volatile unsigned int *) addr)[nr >> 5])) != 0;
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}
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static inline int __test_bit(int nr, const volatile void * addr)
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{
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int * a = (int *) addr;
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int mask;
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a += nr >> 5;
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mask = 1 << (nr & 0x1f);
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return ((mask & *a) != 0);
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}
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#define test_bit(nr,addr) \
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(__builtin_constant_p(nr) ? \
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__constant_test_bit((nr),(addr)) : \
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__test_bit((nr),(addr)))
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extern int find_next_bit(const unsigned long *addr, int size, int offset);
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#define find_first_bit(addr, size) find_next_bit(addr, size, 0)
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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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static inline int find_next_zero_bit(const void *addr, int size, int offset)
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{
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const unsigned long *p = ((const unsigned long *) addr) + (offset >> 5);
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unsigned long result = offset & ~31UL;
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unsigned long tmp;
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if (offset >= size)
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return size;
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size -= result;
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offset &= 31UL;
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if (offset) {
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tmp = *(p++);
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tmp |= ~0UL >> (32-offset);
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if (size < 32)
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goto found_first;
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if (~tmp)
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goto found_middle;
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size -= 32;
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result += 32;
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}
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while (size & ~31UL) {
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if (~(tmp = *(p++)))
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goto found_middle;
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result += 32;
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size -= 32;
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}
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if (!size)
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return result;
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tmp = *p;
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found_first:
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tmp |= ~0UL >> size;
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found_middle:
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return result + ffz(tmp);
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}
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#define ffs(x) generic_ffs(x)
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#define __ffs(x) (ffs(x) - 1)
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/*
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* fls: find last bit set.
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*/
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#define fls(x) \
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({ \
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int bit; \
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\
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asm("scan %1,gr0,%0" : "=r"(bit) : "r"(x)); \
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\
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bit ? 33 - bit : bit; \
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})
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/*
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* Every architecture must define this function. It's the fastest
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* way of searching a 140-bit bitmap where the first 100 bits are
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* unlikely to be set. It's guaranteed that at least one of the 140
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* bits is cleared.
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*/
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static inline int sched_find_first_bit(const unsigned long *b)
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{
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if (unlikely(b[0]))
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return __ffs(b[0]);
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if (unlikely(b[1]))
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return __ffs(b[1]) + 32;
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if (unlikely(b[2]))
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return __ffs(b[2]) + 64;
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if (b[3])
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return __ffs(b[3]) + 96;
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return __ffs(b[4]) + 128;
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}
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/*
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* hweightN: returns the hamming weight (i.e. the number
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* of bits set) of a N-bit word
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*/
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#define hweight32(x) generic_hweight32(x)
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#define hweight16(x) generic_hweight16(x)
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#define hweight8(x) generic_hweight8(x)
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#define ext2_set_bit(nr, addr) test_and_set_bit ((nr) ^ 0x18, (addr))
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#define ext2_clear_bit(nr, addr) test_and_clear_bit((nr) ^ 0x18, (addr))
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#define ext2_set_bit_atomic(lock,nr,addr) ext2_set_bit((nr), addr)
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#define ext2_clear_bit_atomic(lock,nr,addr) ext2_clear_bit((nr), addr)
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static inline int ext2_test_bit(int nr, const volatile void * addr)
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{
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const volatile unsigned char *ADDR = (const unsigned char *) addr;
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int mask;
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ADDR += nr >> 3;
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mask = 1 << (nr & 0x07);
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return ((mask & *ADDR) != 0);
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}
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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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static inline unsigned long ext2_find_next_zero_bit(const void *addr,
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unsigned long size,
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unsigned long offset)
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{
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const unsigned long *p = ((const unsigned long *) addr) + (offset >> 5);
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unsigned long result = offset & ~31UL;
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unsigned long tmp;
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if (offset >= size)
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return size;
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size -= result;
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offset &= 31UL;
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if(offset) {
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/* We hold the little endian value in tmp, but then the
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* shift is illegal. So we could keep a big endian value
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* in tmp, like this:
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*
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* tmp = __swab32(*(p++));
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* tmp |= ~0UL >> (32-offset);
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*
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* but this would decrease preformance, so we change the
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* shift:
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*/
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tmp = *(p++);
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tmp |= __swab32(~0UL >> (32-offset));
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if(size < 32)
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goto found_first;
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if(~tmp)
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goto found_middle;
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size -= 32;
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result += 32;
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}
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while(size & ~31UL) {
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if(~(tmp = *(p++)))
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goto found_middle;
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result += 32;
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size -= 32;
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}
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if(!size)
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return result;
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tmp = *p;
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found_first:
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/* tmp is little endian, so we would have to swab the shift,
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* see above. But then we have to swab tmp below for ffz, so
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* we might as well do this here.
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*/
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return result + ffz(__swab32(tmp) | (~0UL << size));
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found_middle:
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return result + ffz(__swab32(tmp));
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}
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/* Bitmap functions for the minix filesystem. */
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#define minix_test_and_set_bit(nr,addr) ext2_set_bit(nr,addr)
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#define minix_set_bit(nr,addr) ext2_set_bit(nr,addr)
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#define minix_test_and_clear_bit(nr,addr) ext2_clear_bit(nr,addr)
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#define minix_test_bit(nr,addr) ext2_test_bit(nr,addr)
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#define minix_find_first_zero_bit(addr,size) ext2_find_first_zero_bit(addr,size)
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#endif /* __KERNEL__ */
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#endif /* _ASM_BITOPS_H */
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