1/*
  2 * This file is subject to the terms and conditions of the GNU General Public
  3 * License.  See the file "COPYING" in the main directory of this archive
  4 * for more details.
  5 *
  6 * Copyright (c) 1994-1997, 99, 2000, 06, 07 Ralf Baechle (ralf@linux-mips.org)
  7 * Copyright (c) 1999, 2000  Silicon Graphics, Inc.
  8 */
  9#include <linux/bitops.h>
 10#include <linux/bits.h>
 11#include <linux/irqflags.h>
 12#include <linux/export.h>
 13
 14
 15/**
 16 * __mips_set_bit - Atomically set a bit in memory.  This is called by
 17 * set_bit() if it cannot find a faster solution.
 18 * @nr: the bit to set
 19 * @addr: the address to start counting from
 20 */
 21void __mips_set_bit(unsigned long nr, volatile unsigned long *addr)
 22{
 23	volatile unsigned long *a = &addr[BIT_WORD(nr)];
 24	unsigned int bit = nr % BITS_PER_LONG;
 25	unsigned long mask;
 26	unsigned long flags;
 27
 28	mask = 1UL << bit;
 29	raw_local_irq_save(flags);
 30	*a |= mask;
 31	raw_local_irq_restore(flags);
 32}
 33EXPORT_SYMBOL(__mips_set_bit);
 34
 35
 36/**
 37 * __mips_clear_bit - Clears a bit in memory.  This is called by clear_bit() if
 38 * it cannot find a faster solution.
 39 * @nr: Bit to clear
 40 * @addr: Address to start counting from
 41 */
 42void __mips_clear_bit(unsigned long nr, volatile unsigned long *addr)
 43{
 44	volatile unsigned long *a = &addr[BIT_WORD(nr)];
 45	unsigned int bit = nr % BITS_PER_LONG;
 46	unsigned long mask;
 47	unsigned long flags;
 48
 49	mask = 1UL << bit;
 50	raw_local_irq_save(flags);
 51	*a &= ~mask;
 52	raw_local_irq_restore(flags);
 53}
 54EXPORT_SYMBOL(__mips_clear_bit);
 55
 56
 57/**
 58 * __mips_change_bit - Toggle a bit in memory.	This is called by change_bit()
 59 * if it cannot find a faster solution.
 60 * @nr: Bit to change
 61 * @addr: Address to start counting from
 62 */
 63void __mips_change_bit(unsigned long nr, volatile unsigned long *addr)
 64{
 65	volatile unsigned long *a = &addr[BIT_WORD(nr)];
 66	unsigned int bit = nr % BITS_PER_LONG;
 67	unsigned long mask;
 68	unsigned long flags;
 69
 70	mask = 1UL << bit;
 71	raw_local_irq_save(flags);
 72	*a ^= mask;
 73	raw_local_irq_restore(flags);
 74}
 75EXPORT_SYMBOL(__mips_change_bit);
 76
 77
 78/**
 79 * __mips_test_and_set_bit_lock - Set a bit and return its old value.  This is
 80 * called by test_and_set_bit_lock() if it cannot find a faster solution.
 81 * @nr: Bit to set
 82 * @addr: Address to count from
 83 */
 84int __mips_test_and_set_bit_lock(unsigned long nr,
 85				 volatile unsigned long *addr)
 86{
 87	volatile unsigned long *a = &addr[BIT_WORD(nr)];
 88	unsigned int bit = nr % BITS_PER_LONG;
 89	unsigned long mask;
 90	unsigned long flags;
 91	int res;
 92
 93	mask = 1UL << bit;
 94	raw_local_irq_save(flags);
 95	res = (mask & *a) != 0;
 96	*a |= mask;
 97	raw_local_irq_restore(flags);
 98	return res;
 99}
100EXPORT_SYMBOL(__mips_test_and_set_bit_lock);
101
102
103/**
104 * __mips_test_and_clear_bit - Clear a bit and return its old value.  This is
105 * called by test_and_clear_bit() if it cannot find a faster solution.
106 * @nr: Bit to clear
107 * @addr: Address to count from
108 */
109int __mips_test_and_clear_bit(unsigned long nr, volatile unsigned long *addr)
110{
111	volatile unsigned long *a = &addr[BIT_WORD(nr)];
112	unsigned int bit = nr % BITS_PER_LONG;
113	unsigned long mask;
114	unsigned long flags;
115	int res;
116
117	mask = 1UL << bit;
118	raw_local_irq_save(flags);
119	res = (mask & *a) != 0;
120	*a &= ~mask;
121	raw_local_irq_restore(flags);
122	return res;
123}
124EXPORT_SYMBOL(__mips_test_and_clear_bit);
125
126
127/**
128 * __mips_test_and_change_bit - Change a bit and return its old value.	This is
129 * called by test_and_change_bit() if it cannot find a faster solution.
130 * @nr: Bit to change
131 * @addr: Address to count from
132 */
133int __mips_test_and_change_bit(unsigned long nr, volatile unsigned long *addr)
134{
135	volatile unsigned long *a = &addr[BIT_WORD(nr)];
136	unsigned int bit = nr % BITS_PER_LONG;
137	unsigned long mask;
138	unsigned long flags;
139	int res;
140
141	mask = 1UL << bit;
142	raw_local_irq_save(flags);
143	res = (mask & *a) != 0;
144	*a ^= mask;
145	raw_local_irq_restore(flags);
146	return res;
147}
148EXPORT_SYMBOL(__mips_test_and_change_bit);
149
150bool __mips_xor_is_negative_byte(unsigned long mask,
151		volatile unsigned long *addr)
152{
153	unsigned long flags;
154	unsigned long data;
155
156	raw_local_irq_save(flags);
157	data = *addr;
158	*addr = data ^ mask;
159	raw_local_irq_restore(flags);
160
161	return (data & BIT(7)) != 0;
162}