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 <asm/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.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/non-atomic.h> 130#include <asm-generic/bitops/ext2-atomic.h> 131 132#endif /* _ASM_TILE_BITOPS_32_H */ 133