357 строки
9.2 KiB
C
357 строки
9.2 KiB
C
/* SPDX-License-Identifier: GPL-2.0 */
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#ifndef _LINUX_BITOPS_H
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#define _LINUX_BITOPS_H
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#include <asm/types.h>
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#include <linux/bits.h>
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#include <linux/typecheck.h>
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#include <uapi/linux/kernel.h>
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/* Set bits in the first 'n' bytes when loaded from memory */
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#ifdef __LITTLE_ENDIAN
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# define aligned_byte_mask(n) ((1UL << 8*(n))-1)
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#else
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# define aligned_byte_mask(n) (~0xffUL << (BITS_PER_LONG - 8 - 8*(n)))
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#endif
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#define BITS_PER_TYPE(type) (sizeof(type) * BITS_PER_BYTE)
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#define BITS_TO_LONGS(nr) __KERNEL_DIV_ROUND_UP(nr, BITS_PER_TYPE(long))
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#define BITS_TO_U64(nr) __KERNEL_DIV_ROUND_UP(nr, BITS_PER_TYPE(u64))
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#define BITS_TO_U32(nr) __KERNEL_DIV_ROUND_UP(nr, BITS_PER_TYPE(u32))
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#define BITS_TO_BYTES(nr) __KERNEL_DIV_ROUND_UP(nr, BITS_PER_TYPE(char))
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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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* Defined here because those may be needed by architecture-specific static
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* inlines.
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*/
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#include <asm-generic/bitops/generic-non-atomic.h>
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/*
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* Many architecture-specific non-atomic bitops contain inline asm code and due
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* to that the compiler can't optimize them to compile-time expressions or
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* constants. In contrary, generic_*() helpers are defined in pure C and
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* compilers optimize them just well.
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* Therefore, to make `unsigned long foo = 0; __set_bit(BAR, &foo)` effectively
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* equal to `unsigned long foo = BIT(BAR)`, pick the generic C alternative when
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* the arguments can be resolved at compile time. That expression itself is a
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* constant and doesn't bring any functional changes to the rest of cases.
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* The casts to `uintptr_t` are needed to mitigate `-Waddress` warnings when
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* passing a bitmap from .bss or .data (-> `!!addr` is always true).
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*/
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#define bitop(op, nr, addr) \
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((__builtin_constant_p(nr) && \
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__builtin_constant_p((uintptr_t)(addr) != (uintptr_t)NULL) && \
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(uintptr_t)(addr) != (uintptr_t)NULL && \
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__builtin_constant_p(*(const unsigned long *)(addr))) ? \
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const##op(nr, addr) : op(nr, addr))
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#define __set_bit(nr, addr) bitop(___set_bit, nr, addr)
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#define __clear_bit(nr, addr) bitop(___clear_bit, nr, addr)
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#define __change_bit(nr, addr) bitop(___change_bit, nr, addr)
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#define __test_and_set_bit(nr, addr) bitop(___test_and_set_bit, nr, addr)
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#define __test_and_clear_bit(nr, addr) bitop(___test_and_clear_bit, nr, addr)
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#define __test_and_change_bit(nr, addr) bitop(___test_and_change_bit, nr, addr)
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#define test_bit(nr, addr) bitop(_test_bit, nr, addr)
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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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/* Check that the bitops prototypes are sane */
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#define __check_bitop_pr(name) \
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static_assert(__same_type(arch_##name, generic_##name) && \
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__same_type(const_##name, generic_##name) && \
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__same_type(_##name, generic_##name))
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__check_bitop_pr(__set_bit);
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__check_bitop_pr(__clear_bit);
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__check_bitop_pr(__change_bit);
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__check_bitop_pr(__test_and_set_bit);
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__check_bitop_pr(__test_and_clear_bit);
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__check_bitop_pr(__test_and_change_bit);
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__check_bitop_pr(test_bit);
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#undef __check_bitop_pr
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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 __always_inline unsigned long hweight_long(unsigned long w)
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{
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return sizeof(w) == 4 ? hweight32(w) : hweight64((__u64)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 & 63)) | (word >> ((-shift) & 63));
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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 & 63)) | (word << ((-shift) & 63));
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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 & 31)) | (word >> ((-shift) & 31));
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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 & 31)) | (word << ((-shift) & 31));
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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 & 15)) | (word >> ((-shift) & 15));
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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 & 15)) | (word << ((-shift) & 15));
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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 & 7)) | (word >> ((-shift) & 7));
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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 & 7)) | (word << ((-shift) & 7));
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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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* This is safe to use for 16- and 8-bit types as well.
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*/
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static __always_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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/**
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* sign_extend64 - sign extend a 64-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<64) to sign bit
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*/
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static __always_inline __s64 sign_extend64(__u64 value, int index)
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{
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__u8 shift = 63 - index;
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return (__s64)(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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static inline int get_count_order(unsigned int count)
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{
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if (count == 0)
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return -1;
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return fls(--count);
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}
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/**
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* get_count_order_long - get order after rounding @l up to power of 2
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* @l: parameter
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*
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* it is same as get_count_order() but with long type parameter
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*/
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static inline int get_count_order_long(unsigned long l)
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{
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if (l == 0UL)
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return -1;
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return (int)fls_long(--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 synonym 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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/**
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* assign_bit - Assign value to a bit in memory
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* @nr: the bit to set
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* @addr: the address to start counting from
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* @value: the value to assign
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*/
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static __always_inline void assign_bit(long nr, volatile unsigned long *addr,
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bool value)
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{
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if (value)
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set_bit(nr, addr);
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else
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clear_bit(nr, addr);
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}
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static __always_inline void __assign_bit(long nr, volatile unsigned long *addr,
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bool value)
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{
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if (value)
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__set_bit(nr, addr);
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else
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__clear_bit(nr, addr);
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}
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/**
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* __ptr_set_bit - Set bit in a pointer's value
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* @nr: the bit to set
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* @addr: the address of the pointer variable
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*
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* Example:
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* void *p = foo();
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* __ptr_set_bit(bit, &p);
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*/
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#define __ptr_set_bit(nr, addr) \
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({ \
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typecheck_pointer(*(addr)); \
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__set_bit(nr, (unsigned long *)(addr)); \
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})
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/**
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* __ptr_clear_bit - Clear bit in a pointer's value
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* @nr: the bit to clear
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* @addr: the address of the pointer variable
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*
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* Example:
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* void *p = foo();
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* __ptr_clear_bit(bit, &p);
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*/
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#define __ptr_clear_bit(nr, addr) \
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({ \
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typecheck_pointer(*(addr)); \
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__clear_bit(nr, (unsigned long *)(addr)); \
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})
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/**
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* __ptr_test_bit - Test bit in a pointer's value
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* @nr: the bit to test
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* @addr: the address of the pointer variable
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*
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* Example:
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* void *p = foo();
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* if (__ptr_test_bit(bit, &p)) {
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* ...
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* } else {
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* ...
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* }
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*/
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#define __ptr_test_bit(nr, addr) \
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({ \
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typecheck_pointer(*(addr)); \
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test_bit(nr, (unsigned long *)(addr)); \
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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__ = READ_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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old__; \
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})
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#endif
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#ifndef bit_clear_unless
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#define bit_clear_unless(ptr, clear, test) \
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({ \
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const typeof(*(ptr)) clear__ = (clear), test__ = (test);\
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typeof(*(ptr)) old__, new__; \
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\
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do { \
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old__ = READ_ONCE(*(ptr)); \
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new__ = old__ & ~clear__; \
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} while (!(old__ & test__) && \
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cmpxchg(ptr, old__, new__) != old__); \
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\
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!(old__ & test__); \
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})
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#endif
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#endif /* __KERNEL__ */
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#endif
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