fce877e3a4
Avoid accidental misuse by failing to compile things Suggested-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Linus Torvalds <torvalds@linux-foundation.org> LKML-Reference: <new-submission> Signed-off-by: Ingo Molnar <mingo@elte.hu>
219 lines
5.4 KiB
C
219 lines
5.4 KiB
C
#ifndef _LINUX_BITOPS_H
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#define _LINUX_BITOPS_H
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#include <asm/types.h>
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#ifdef __KERNEL__
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#define BIT(nr) (1UL << (nr))
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#define BIT_MASK(nr) (1UL << ((nr) % BITS_PER_LONG))
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#define BIT_WORD(nr) ((nr) / BITS_PER_LONG)
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#define BITS_PER_BYTE 8
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#define BITS_TO_LONGS(nr) DIV_ROUND_UP(nr, BITS_PER_BYTE * sizeof(long))
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#endif
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/*
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* Include this here because some architectures need generic_ffs/fls in
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* scope
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*/
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#include <asm/bitops.h>
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#define for_each_bit(bit, addr, size) \
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for ((bit) = find_first_bit((addr), (size)); \
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(bit) < (size); \
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(bit) = find_next_bit((addr), (size), (bit) + 1))
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static __inline__ int get_bitmask_order(unsigned int count)
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{
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int order;
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order = fls(count);
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return order; /* We could be slightly more clever with -1 here... */
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}
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static __inline__ int get_count_order(unsigned int count)
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{
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int order;
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order = fls(count) - 1;
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if (count & (count - 1))
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order++;
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return order;
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}
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static inline unsigned long hweight_long(unsigned long w)
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{
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return sizeof(w) == 4 ? hweight32(w) : hweight64(w);
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}
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/*
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* Clearly slow versions of the hweightN() functions, their benefit is
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* of course compile time evaluation of constant arguments.
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*/
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#define HWEIGHT8(w) \
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( BUILD_BUG_ON_ZERO(!__builtin_constant_p(w)) + \
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(!!((w) & (1ULL << 0))) + \
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(!!((w) & (1ULL << 1))) + \
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(!!((w) & (1ULL << 2))) + \
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(!!((w) & (1ULL << 3))) + \
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(!!((w) & (1ULL << 4))) + \
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(!!((w) & (1ULL << 5))) + \
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(!!((w) & (1ULL << 6))) + \
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(!!((w) & (1ULL << 7))) )
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#define HWEIGHT16(w) (HWEIGHT8(w) + HWEIGHT8((w) >> 8))
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#define HWEIGHT32(w) (HWEIGHT16(w) + HWEIGHT16((w) >> 16))
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#define HWEIGHT64(w) (HWEIGHT32(w) + HWEIGHT32((w) >> 32))
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/*
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* Type invariant version that simply casts things to the
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* largest type.
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*/
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#define HWEIGHT(w) HWEIGHT64((u64)(w))
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/**
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* rol32 - rotate a 32-bit value left
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* @word: value to rotate
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* @shift: bits to roll
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*/
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static inline __u32 rol32(__u32 word, unsigned int shift)
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{
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return (word << shift) | (word >> (32 - shift));
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}
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/**
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* ror32 - rotate a 32-bit value right
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* @word: value to rotate
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* @shift: bits to roll
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*/
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static inline __u32 ror32(__u32 word, unsigned int shift)
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{
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return (word >> shift) | (word << (32 - shift));
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}
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/**
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* rol16 - rotate a 16-bit value left
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* @word: value to rotate
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* @shift: bits to roll
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*/
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static inline __u16 rol16(__u16 word, unsigned int shift)
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{
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return (word << shift) | (word >> (16 - shift));
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}
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/**
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* ror16 - rotate a 16-bit value right
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* @word: value to rotate
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* @shift: bits to roll
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*/
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static inline __u16 ror16(__u16 word, unsigned int shift)
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{
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return (word >> shift) | (word << (16 - shift));
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}
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/**
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* rol8 - rotate an 8-bit value left
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* @word: value to rotate
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* @shift: bits to roll
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*/
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static inline __u8 rol8(__u8 word, unsigned int shift)
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{
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return (word << shift) | (word >> (8 - shift));
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}
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/**
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* ror8 - rotate an 8-bit value right
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* @word: value to rotate
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* @shift: bits to roll
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*/
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static inline __u8 ror8(__u8 word, unsigned int shift)
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{
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return (word >> shift) | (word << (8 - shift));
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}
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static inline unsigned fls_long(unsigned long l)
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{
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if (sizeof(l) == 4)
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return fls(l);
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return fls64(l);
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}
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/**
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* __ffs64 - find first set bit in a 64 bit word
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* @word: The 64 bit word
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*
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* On 64 bit arches this is a synomyn for __ffs
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* The result is not defined if no bits are set, so check that @word
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* is non-zero before calling this.
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*/
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static inline unsigned long __ffs64(u64 word)
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{
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#if BITS_PER_LONG == 32
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if (((u32)word) == 0UL)
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return __ffs((u32)(word >> 32)) + 32;
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#elif BITS_PER_LONG != 64
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#error BITS_PER_LONG not 32 or 64
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#endif
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return __ffs((unsigned long)word);
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}
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#ifdef __KERNEL__
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#ifdef CONFIG_GENERIC_FIND_FIRST_BIT
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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.
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*/
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extern unsigned long find_first_bit(const unsigned long *addr,
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unsigned long size);
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/**
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* find_first_zero_bit - find the first cleared 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 cleared bit.
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*/
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extern unsigned long find_first_zero_bit(const unsigned long *addr,
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unsigned long size);
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#endif /* CONFIG_GENERIC_FIND_FIRST_BIT */
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#ifdef CONFIG_GENERIC_FIND_LAST_BIT
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/**
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* find_last_bit - find the last 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, or size.
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*/
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extern unsigned long find_last_bit(const unsigned long *addr,
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unsigned long size);
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#endif /* CONFIG_GENERIC_FIND_LAST_BIT */
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#ifdef CONFIG_GENERIC_FIND_NEXT_BIT
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/**
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* find_next_bit - find the next set bit in a memory region
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* @addr: The address to base the search on
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* @offset: The bitnumber to start searching at
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* @size: The bitmap size in bits
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*/
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extern unsigned long find_next_bit(const unsigned long *addr,
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unsigned long size, unsigned long offset);
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/**
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* find_next_zero_bit - find the next cleared bit in a memory region
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* @addr: The address to base the search on
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* @offset: The bitnumber to start searching at
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* @size: The bitmap size in bits
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*/
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extern unsigned long find_next_zero_bit(const unsigned long *addr,
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unsigned long size,
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unsigned long offset);
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#endif /* CONFIG_GENERIC_FIND_NEXT_BIT */
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#endif /* __KERNEL__ */
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#endif
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