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