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/*
* Copyright 2010 Tilera Corporation. All Rights Reserved.
*
* 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, GOOD TITLE or
* NON INFRINGEMENT. See the GNU General Public License for
* more details.
*/
#ifndef _ASM_TILE_BITOPS_32_H
#define _ASM_TILE_BITOPS_32_H
#include <linux/compiler.h>
#include <linux/atomic.h>
/* Tile-specific routines to support <asm/bitops.h>. */
unsigned long _atomic_or(volatile unsigned long *p, unsigned long mask);
unsigned long _atomic_andn(volatile unsigned long *p, unsigned long mask);
unsigned long _atomic_xor(volatile unsigned long *p, unsigned long mask);
/**
* set_bit - Atomically set a bit in memory
* @nr: the bit to set
* @addr: the address to start counting from
*
* This function is atomic and may not be reordered.
* See __set_bit() if you do not require the atomic 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(unsigned nr, volatile unsigned long *addr)
{
_atomic_or(addr + BIT_WORD(nr), BIT_MASK(nr));
}
/**
* clear_bit - Clears a bit in memory
* @nr: Bit to clear
* @addr: Address to start counting from
*
* clear_bit() is atomic and may not be reordered.
* See __clear_bit() if you do not require the atomic guarantees.
* Note that @nr may be almost arbitrarily large; this function is not
* restricted to acting on a single-word quantity.
*
* clear_bit() may not contain a memory barrier, so if it is used for
* locking purposes, you should call smp_mb__before_clear_bit() and/or
* smp_mb__after_clear_bit() to ensure changes are visible on other cpus.
*/
static inline void clear_bit(unsigned nr, volatile unsigned long *addr)
{
_atomic_andn(addr + BIT_WORD(nr), BIT_MASK(nr));
}
/**
* change_bit - Toggle a bit in memory
* @nr: Bit to change
* @addr: Address to start counting from
*
* change_bit() is atomic and may not be reordered.
* See __change_bit() if you do not require the atomic guarantees.
* 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(unsigned nr, volatile unsigned long *addr)
{
_atomic_xor(addr + BIT_WORD(nr), BIT_MASK(nr));
}
/**
* test_and_set_bit - Set a bit and return its old value
* @nr: Bit to set
* @addr: Address to count from
*
* This operation is atomic and cannot be reordered.
* It also implies a memory barrier.
*/
static inline int test_and_set_bit(unsigned nr, volatile unsigned long *addr)
{
unsigned long mask = BIT_MASK(nr);
addr += BIT_WORD(nr);
smp_mb(); /* barrier for proper semantics */
return (_atomic_or(addr, mask) & mask) != 0;
}
/**
* test_and_clear_bit - Clear a bit and return its old value
* @nr: Bit to clear
* @addr: Address to count from
*
* This operation is atomic and cannot be reordered.
* It also implies a memory barrier.
*/
static inline int test_and_clear_bit(unsigned nr, volatile unsigned long *addr)
{
unsigned long mask = BIT_MASK(nr);
addr += BIT_WORD(nr);
smp_mb(); /* barrier for proper semantics */
return (_atomic_andn(addr, mask) & mask) != 0;
}
/**
* 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(unsigned nr,
volatile unsigned long *addr)
{
unsigned long mask = BIT_MASK(nr);
addr += BIT_WORD(nr);
smp_mb(); /* barrier for proper semantics */
return (_atomic_xor(addr, mask) & mask) != 0;
}
/* See discussion at smp_mb__before_atomic_dec() in <asm/atomic_32.h>. */
#define smp_mb__before_clear_bit() smp_mb()
#define smp_mb__after_clear_bit() do {} while (0)
#include <asm-generic/bitops/ext2-atomic.h>
#endif /* _ASM_TILE_BITOPS_32_H */
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