1/*
  2 * Copyright 2010 Tilera Corporation. All Rights Reserved.
  3 *
  4 *   This program is free software; you can redistribute it and/or
  5 *   modify it under the terms of the GNU General Public License
  6 *   as published by the Free Software Foundation, version 2.
  7 *
  8 *   This program is distributed in the hope that it will be useful, but
  9 *   WITHOUT ANY WARRANTY; without even the implied warranty of
 10 *   MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE, GOOD TITLE or
 11 *   NON INFRINGEMENT.  See the GNU General Public License for
 12 *   more details.
 13 */
 14
 15#ifndef _ASM_TILE_BITOPS_32_H
 16#define _ASM_TILE_BITOPS_32_H
 17
 18#include <linux/compiler.h>
 19#include <linux/atomic.h>
 20#include <asm/system.h>
 21
 22/* Tile-specific routines to support <asm/bitops.h>. */
 23unsigned long _atomic_or(volatile unsigned long *p, unsigned long mask);
 24unsigned long _atomic_andn(volatile unsigned long *p, unsigned long mask);
 25unsigned long _atomic_xor(volatile unsigned long *p, unsigned long mask);
 26
 27/**
 28 * set_bit - Atomically set a bit in memory
 29 * @nr: the bit to set
 30 * @addr: the address to start counting from
 31 *
 32 * This function is atomic and may not be reordered.
 33 * See __set_bit() if you do not require the atomic guarantees.
 34 * Note that @nr may be almost arbitrarily large; this function is not
 35 * restricted to acting on a single-word quantity.
 36 */
 37static inline void set_bit(unsigned nr, volatile unsigned long *addr)
 38{
 39	_atomic_or(addr + BIT_WORD(nr), BIT_MASK(nr));
 40}
 41
 42/**
 43 * clear_bit - Clears a bit in memory
 44 * @nr: Bit to clear
 45 * @addr: Address to start counting from
 46 *
 47 * clear_bit() is atomic and may not be reordered.
 48 * See __clear_bit() if you do not require the atomic guarantees.
 49 * Note that @nr may be almost arbitrarily large; this function is not
 50 * restricted to acting on a single-word quantity.
 51 *
 52 * clear_bit() may not contain a memory barrier, so if it is used for
 53 * locking purposes, you should call smp_mb__before_clear_bit() and/or
 54 * smp_mb__after_clear_bit() to ensure changes are visible on other cpus.
 55 */
 56static inline void clear_bit(unsigned nr, volatile unsigned long *addr)
 57{
 58	_atomic_andn(addr + BIT_WORD(nr), BIT_MASK(nr));
 59}
 60
 61/**
 62 * change_bit - Toggle a bit in memory
 63 * @nr: Bit to change
 64 * @addr: Address to start counting from
 65 *
 66 * change_bit() is atomic and may not be reordered.
 67 * See __change_bit() if you do not require the atomic guarantees.
 68 * Note that @nr may be almost arbitrarily large; this function is not
 69 * restricted to acting on a single-word quantity.
 70 */
 71static inline void change_bit(unsigned nr, volatile unsigned long *addr)
 72{
 73	_atomic_xor(addr + BIT_WORD(nr), BIT_MASK(nr));
 74}
 75
 76/**
 77 * test_and_set_bit - Set a bit and return its old value
 78 * @nr: Bit to set
 79 * @addr: Address to count from
 80 *
 81 * This operation is atomic and cannot be reordered.
 82 * It also implies a memory barrier.
 83 */
 84static inline int test_and_set_bit(unsigned nr, volatile unsigned long *addr)
 85{
 86	unsigned long mask = BIT_MASK(nr);
 87	addr += BIT_WORD(nr);
 88	smp_mb();  /* barrier for proper semantics */
 89	return (_atomic_or(addr, mask) & mask) != 0;
 90}
 91
 92/**
 93 * test_and_clear_bit - Clear a bit and return its old value
 94 * @nr: Bit to clear
 95 * @addr: Address to count from
 96 *
 97 * This operation is atomic and cannot be reordered.
 98 * It also implies a memory barrier.
 99 */
100static inline int test_and_clear_bit(unsigned nr, volatile unsigned long *addr)
101{
102	unsigned long mask = BIT_MASK(nr);
103	addr += BIT_WORD(nr);
104	smp_mb();  /* barrier for proper semantics */
105	return (_atomic_andn(addr, mask) & mask) != 0;
106}
107
108/**
109 * test_and_change_bit - Change a bit and return its old value
110 * @nr: Bit to change
111 * @addr: Address to count from
112 *
113 * This operation is atomic and cannot be reordered.
114 * It also implies a memory barrier.
115 */
116static inline int test_and_change_bit(unsigned nr,
117				      volatile unsigned long *addr)
118{
119	unsigned long mask = BIT_MASK(nr);
120	addr += BIT_WORD(nr);
121	smp_mb();  /* barrier for proper semantics */
122	return (_atomic_xor(addr, mask) & mask) != 0;
123}
124
125/* See discussion at smp_mb__before_atomic_dec() in <asm/atomic_32.h>. */
126#define smp_mb__before_clear_bit()	smp_mb()
127#define smp_mb__after_clear_bit()	do {} while (0)
128
129#include <asm-generic/bitops/ext2-atomic.h>
130
131#endif /* _ASM_TILE_BITOPS_32_H */