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9347ce54cd
I mis-read the documentation. After looking at it again the documentation is actually as clear as it can be, it's just that I didn't actually read it in order and therefor did the wrong thing. Signed-off-by: Palmer Dabbelt <palmer@sifive.com>
219 lines
6.2 KiB
C
219 lines
6.2 KiB
C
/*
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* Copyright (C) 2012 Regents of the University of California
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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, version 2.
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*
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* This program is distributed in the hope that it will be useful,
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* but WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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* GNU General Public License for more details.
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*/
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#ifndef _ASM_RISCV_BITOPS_H
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#define _ASM_RISCV_BITOPS_H
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#ifndef _LINUX_BITOPS_H
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#error "Only <linux/bitops.h> can be included directly"
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#endif /* _LINUX_BITOPS_H */
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#include <linux/compiler.h>
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#include <linux/irqflags.h>
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#include <asm/barrier.h>
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#include <asm/bitsperlong.h>
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#ifndef smp_mb__before_clear_bit
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#define smp_mb__before_clear_bit() smp_mb()
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#define smp_mb__after_clear_bit() smp_mb()
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#endif /* smp_mb__before_clear_bit */
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#include <asm-generic/bitops/__ffs.h>
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#include <asm-generic/bitops/ffz.h>
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#include <asm-generic/bitops/fls.h>
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#include <asm-generic/bitops/__fls.h>
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#include <asm-generic/bitops/fls64.h>
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#include <asm-generic/bitops/find.h>
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#include <asm-generic/bitops/sched.h>
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#include <asm-generic/bitops/ffs.h>
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#include <asm-generic/bitops/hweight.h>
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#if (BITS_PER_LONG == 64)
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#define __AMO(op) "amo" #op ".d"
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#elif (BITS_PER_LONG == 32)
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#define __AMO(op) "amo" #op ".w"
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#else
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#error "Unexpected BITS_PER_LONG"
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#endif
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#define __test_and_op_bit_ord(op, mod, nr, addr, ord) \
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({ \
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unsigned long __res, __mask; \
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__mask = BIT_MASK(nr); \
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__asm__ __volatile__ ( \
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__AMO(op) #ord " %0, %2, %1" \
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: "=r" (__res), "+A" (addr[BIT_WORD(nr)]) \
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: "r" (mod(__mask)) \
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: "memory"); \
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((__res & __mask) != 0); \
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})
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#define __op_bit_ord(op, mod, nr, addr, ord) \
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__asm__ __volatile__ ( \
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__AMO(op) #ord " zero, %1, %0" \
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: "+A" (addr[BIT_WORD(nr)]) \
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: "r" (mod(BIT_MASK(nr))) \
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: "memory");
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#define __test_and_op_bit(op, mod, nr, addr) \
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__test_and_op_bit_ord(op, mod, nr, addr, .aqrl)
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#define __op_bit(op, mod, nr, addr) \
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__op_bit_ord(op, mod, nr, addr, )
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/* Bitmask modifiers */
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#define __NOP(x) (x)
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#define __NOT(x) (~(x))
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/**
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* test_and_set_bit - Set a bit and return its old value
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* @nr: Bit to set
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* @addr: Address to count from
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*
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* This operation may be reordered on other architectures than x86.
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*/
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static inline int test_and_set_bit(int nr, volatile unsigned long *addr)
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{
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return __test_and_op_bit(or, __NOP, nr, addr);
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}
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/**
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* test_and_clear_bit - Clear a bit and return its old value
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* @nr: Bit to clear
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* @addr: Address to count from
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*
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* This operation can be reordered on other architectures other than x86.
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*/
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static inline int test_and_clear_bit(int nr, volatile unsigned long *addr)
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{
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return __test_and_op_bit(and, __NOT, nr, addr);
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}
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/**
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* test_and_change_bit - Change a bit and return its old value
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* @nr: Bit to change
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* @addr: Address to count from
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*
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* This operation is atomic and cannot be reordered.
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* It also implies a memory barrier.
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*/
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static inline int test_and_change_bit(int nr, volatile unsigned long *addr)
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{
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return __test_and_op_bit(xor, __NOP, nr, addr);
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}
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/**
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* set_bit - Atomically set 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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*
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* Note: there are no guarantees that this function will not be reordered
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* on non x86 architectures, so if you are writing portable code,
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* make sure not to rely on its reordering guarantees.
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*
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* Note that @nr may be almost arbitrarily large; this function is not
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* restricted to acting on a single-word quantity.
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*/
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static inline void set_bit(int nr, volatile unsigned long *addr)
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{
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__op_bit(or, __NOP, nr, addr);
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}
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/**
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* clear_bit - Clears a bit in memory
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* @nr: Bit to clear
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* @addr: Address to start counting from
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*
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* Note: there are no guarantees that this function will not be reordered
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* on non x86 architectures, so if you are writing portable code,
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* make sure not to rely on its reordering guarantees.
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*/
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static inline void clear_bit(int nr, volatile unsigned long *addr)
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{
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__op_bit(and, __NOT, nr, addr);
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}
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/**
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* change_bit - Toggle a bit in memory
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* @nr: Bit to change
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* @addr: Address to start counting from
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*
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* change_bit() may be reordered on other architectures than x86.
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* Note that @nr may be almost arbitrarily large; this function is not
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* restricted to acting on a single-word quantity.
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*/
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static inline void change_bit(int nr, volatile unsigned long *addr)
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{
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__op_bit(xor, __NOP, nr, addr);
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}
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/**
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* test_and_set_bit_lock - Set a bit and return its old value, for lock
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* @nr: Bit to set
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* @addr: Address to count from
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*
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* This operation is atomic and provides acquire barrier semantics.
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* It can be used to implement bit locks.
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*/
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static inline int test_and_set_bit_lock(
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unsigned long nr, volatile unsigned long *addr)
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{
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return __test_and_op_bit_ord(or, __NOP, nr, addr, .aq);
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}
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/**
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* clear_bit_unlock - Clear a bit in memory, for unlock
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* @nr: the bit to set
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* @addr: the address to start counting from
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*
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* This operation is atomic and provides release barrier semantics.
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*/
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static inline void clear_bit_unlock(
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unsigned long nr, volatile unsigned long *addr)
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{
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__op_bit_ord(and, __NOT, nr, addr, .rl);
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}
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/**
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* __clear_bit_unlock - Clear a bit in memory, for unlock
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* @nr: the bit to set
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* @addr: the address to start counting from
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*
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* This operation is like clear_bit_unlock, however it is not atomic.
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* It does provide release barrier semantics so it can be used to unlock
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* a bit lock, however it would only be used if no other CPU can modify
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* any bits in the memory until the lock is released (a good example is
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* if the bit lock itself protects access to the other bits in the word).
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*
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* On RISC-V systems there seems to be no benefit to taking advantage of the
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* non-atomic property here: it's a lot more instructions and we still have to
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* provide release semantics anyway.
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*/
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static inline void __clear_bit_unlock(
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unsigned long nr, volatile unsigned long *addr)
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{
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clear_bit_unlock(nr, addr);
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}
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#undef __test_and_op_bit
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#undef __op_bit
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#undef __NOP
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#undef __NOT
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#undef __AMO
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#include <asm-generic/bitops/non-atomic.h>
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#include <asm-generic/bitops/le.h>
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#include <asm-generic/bitops/ext2-atomic.h>
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#endif /* _ASM_RISCV_BITOPS_H */
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