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 */
21 void __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 }
33 EXPORT_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 */
42 void __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 }
54 EXPORT_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 */
63 void __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 }
75 EXPORT_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 */
84 int __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 }
100 EXPORT_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 */
109 int __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 }
124 EXPORT_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 */
133 int __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 }
148 EXPORT_SYMBOL(__mips_test_and_change_bit);
149
150 bool __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 }
163
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