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![Peter Zijlstra](/assets/img/avatar_default.png)
Since the smp_mb__{before,after}*() ops are fundamentally dependent on how an arch can implement atomics it doesn't make sense to have 3 variants of them. They must all be the same. Furthermore, the 3 variants suggest they're only valid for those 3 atomic ops, while we have many more where they could be applied. So move away from smp_mb__{before,after}_{atomic,clear}_{dec,inc,bit}() and reduce the interface to just the two: smp_mb__{before,after}_atomic(). This patch prepares the way by introducing default implementations in asm-generic/barrier.h that default to a full barrier and providing __deprecated inlines for the previous 6 barriers if they're not provided by the arch. This should allow for a mostly painless transition (lots of deprecated warns in the interim). Signed-off-by: Peter Zijlstra <peterz@infradead.org> Acked-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Link: http://lkml.kernel.org/n/tip-wr59327qdyi9mbzn6x937s4e@git.kernel.org Cc: Arnd Bergmann <arnd@arndb.de> Cc: "Chen, Gong" <gong.chen@linux.intel.com> Cc: John Sullivan <jsrhbz@kanargh.force9.co.uk> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Mauro Carvalho Chehab <m.chehab@samsung.com> Cc: Srinivas Pandruvada <srinivas.pandruvada@linux.intel.com> Cc: "Theodore Ts'o" <tytso@mit.edu> Cc: linux-arch@vger.kernel.org Cc: linux-kernel@vger.kernel.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
247 lines
6.1 KiB
C
247 lines
6.1 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_ULL(nr) (1ULL << (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 BIT_ULL_MASK(nr) (1ULL << ((nr) % BITS_PER_LONG_LONG))
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#define BIT_ULL_WORD(nr) ((nr) / BITS_PER_LONG_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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* Create a contiguous bitmask starting at bit position @l and ending at
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* position @h. For example
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* GENMASK_ULL(39, 21) gives us the 64bit vector 0x000000ffffe00000.
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*/
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#define GENMASK(h, l) (((U32_C(1) << ((h) - (l) + 1)) - 1) << (l))
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#define GENMASK_ULL(h, l) (((U64_C(1) << ((h) - (l) + 1)) - 1) << (l))
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extern unsigned int __sw_hweight8(unsigned int w);
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extern unsigned int __sw_hweight16(unsigned int w);
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extern unsigned int __sw_hweight32(unsigned int w);
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extern unsigned long __sw_hweight64(__u64 w);
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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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/*
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* Provide __deprecated wrappers for the new interface, avoid flag day changes.
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* We need the ugly external functions to break header recursion hell.
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*/
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#ifndef smp_mb__before_clear_bit
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static inline void __deprecated smp_mb__before_clear_bit(void)
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{
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extern void __smp_mb__before_atomic(void);
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__smp_mb__before_atomic();
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}
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#endif
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#ifndef smp_mb__after_clear_bit
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static inline void __deprecated smp_mb__after_clear_bit(void)
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{
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extern void __smp_mb__after_atomic(void);
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__smp_mb__after_atomic();
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}
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#endif
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#define for_each_set_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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/* same as for_each_set_bit() but use bit as value to start with */
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#define for_each_set_bit_from(bit, addr, size) \
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for ((bit) = find_next_bit((addr), (size), (bit)); \
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(bit) < (size); \
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(bit) = find_next_bit((addr), (size), (bit) + 1))
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#define for_each_clear_bit(bit, addr, size) \
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for ((bit) = find_first_zero_bit((addr), (size)); \
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(bit) < (size); \
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(bit) = find_next_zero_bit((addr), (size), (bit) + 1))
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/* same as for_each_clear_bit() but use bit as value to start with */
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#define for_each_clear_bit_from(bit, addr, size) \
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for ((bit) = find_next_zero_bit((addr), (size), (bit)); \
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(bit) < (size); \
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(bit) = find_next_zero_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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* rol64 - rotate a 64-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 __u64 rol64(__u64 word, unsigned int shift)
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{
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return (word << shift) | (word >> (64 - shift));
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}
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/**
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* ror64 - rotate a 64-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 __u64 ror64(__u64 word, unsigned int shift)
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{
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return (word >> shift) | (word << (64 - shift));
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}
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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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/**
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* sign_extend32 - sign extend a 32-bit value using specified bit as sign-bit
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* @value: value to sign extend
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* @index: 0 based bit index (0<=index<32) to sign bit
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*/
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static inline __s32 sign_extend32(__u32 value, int index)
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{
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__u8 shift = 31 - index;
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return (__s32)(value << shift) >> 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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#ifndef set_mask_bits
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#define set_mask_bits(ptr, _mask, _bits) \
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({ \
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const typeof(*ptr) mask = (_mask), bits = (_bits); \
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typeof(*ptr) old, new; \
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\
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do { \
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old = ACCESS_ONCE(*ptr); \
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new = (old & ~mask) | bits; \
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} while (cmpxchg(ptr, old, new) != old); \
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\
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new; \
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})
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#endif
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#ifndef 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
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#endif /* __KERNEL__ */
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#endif
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