arch/mips/lib/bitops.c

   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/irqflags.h>
  11 #include <linux/export.h>
  12
  13
  14 /**
  15  * __mips_set_bit - Atomically set a bit in memory.  This is called by
  16  * set_bit() if it cannot find a faster solution.
  17  * @nr: the bit to set
  18  * @addr: the address to start counting from
  19  */
  20 void __mips_set_bit(unsigned long nr, volatile unsigned long *addr)
  21 {
  22         unsigned long *a = (unsigned long *)addr;
  23         unsigned bit = nr & SZLONG_MASK;
  24         unsigned long mask;
  25         unsigned long flags;
  26
  27         a += nr >> SZLONG_LOG;
  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         unsigned long *a = (unsigned long *)addr;
  45         unsigned bit = nr & SZLONG_MASK;
  46         unsigned long mask;
  47         unsigned long flags;
  48
  49         a += nr >> SZLONG_LOG;
  50         mask = 1UL << bit;
  51         raw_local_irq_save(flags);
  52         *a &= ~mask;
  53         raw_local_irq_restore(flags);
  54 }
  55 EXPORT_SYMBOL(__mips_clear_bit);
  56
  57
  58 /**
  59  * __mips_change_bit - Toggle a bit in memory.  This is called by change_bit()
  60  * if it cannot find a faster solution.
  61  * @nr: Bit to change
  62  * @addr: Address to start counting from
  63  */
  64 void __mips_change_bit(unsigned long nr, volatile unsigned long *addr)
  65 {
  66         unsigned long *a = (unsigned long *)addr;
  67         unsigned bit = nr & SZLONG_MASK;
  68         unsigned long mask;
  69         unsigned long flags;
  70
  71         a += nr >> SZLONG_LOG;
  72         mask = 1UL << bit;
  73         raw_local_irq_save(flags);
  74         *a ^= mask;
  75         raw_local_irq_restore(flags);
  76 }
  77 EXPORT_SYMBOL(__mips_change_bit);
  78
  79
  80 /**
  81  * __mips_test_and_set_bit - Set a bit and return its old value.  This is
  82  * called by test_and_set_bit() if it cannot find a faster solution.
  83  * @nr: Bit to set
  84  * @addr: Address to count from
  85  */
  86 int __mips_test_and_set_bit(unsigned long nr,
  87                             volatile unsigned long *addr)
  88 {
  89         unsigned long *a = (unsigned long *)addr;
  90         unsigned bit = nr & SZLONG_MASK;
  91         unsigned long mask;
  92         unsigned long flags;
  93         int res;
  94
  95         a += nr >> SZLONG_LOG;
  96         mask = 1UL << bit;
  97         raw_local_irq_save(flags);
  98         res = (mask & *a) != 0;
  99         *a |= mask;
 100         raw_local_irq_restore(flags);
 101         return res;
 102 }
 103 EXPORT_SYMBOL(__mips_test_and_set_bit);
 104
 105
 106 /**
 107  * __mips_test_and_set_bit_lock - Set a bit and return its old value.  This is
 108  * called by test_and_set_bit_lock() if it cannot find a faster solution.
 109  * @nr: Bit to set
 110  * @addr: Address to count from
 111  */
 112 int __mips_test_and_set_bit_lock(unsigned long nr,
 113                                  volatile unsigned long *addr)
 114 {
 115         unsigned long *a = (unsigned long *)addr;
 116         unsigned bit = nr & SZLONG_MASK;
 117         unsigned long mask;
 118         unsigned long flags;
 119         int res;
 120
 121         a += nr >> SZLONG_LOG;
 122         mask = 1UL << bit;
 123         raw_local_irq_save(flags);
 124         res = (mask & *a) != 0;
 125         *a |= mask;
 126         raw_local_irq_restore(flags);
 127         return res;
 128 }
 129 EXPORT_SYMBOL(__mips_test_and_set_bit_lock);
 130
 131
 132 /**
 133  * __mips_test_and_clear_bit - Clear a bit and return its old value.  This is
 134  * called by test_and_clear_bit() if it cannot find a faster solution.
 135  * @nr: Bit to clear
 136  * @addr: Address to count from
 137  */
 138 int __mips_test_and_clear_bit(unsigned long nr, volatile unsigned long *addr)
 139 {
 140         unsigned long *a = (unsigned long *)addr;
 141         unsigned bit = nr & SZLONG_MASK;
 142         unsigned long mask;
 143         unsigned long flags;
 144         int res;
 145
 146         a += nr >> SZLONG_LOG;
 147         mask = 1UL << bit;
 148         raw_local_irq_save(flags);
 149         res = (mask & *a) != 0;
 150         *a &= ~mask;
 151         raw_local_irq_restore(flags);
 152         return res;
 153 }
 154 EXPORT_SYMBOL(__mips_test_and_clear_bit);
 155
 156
 157 /**
 158  * __mips_test_and_change_bit - Change a bit and return its old value.  This is
 159  * called by test_and_change_bit() if it cannot find a faster solution.
 160  * @nr: Bit to change
 161  * @addr: Address to count from
 162  */
 163 int __mips_test_and_change_bit(unsigned long nr, volatile unsigned long *addr)
 164 {
 165         unsigned long *a = (unsigned long *)addr;
 166         unsigned bit = nr & SZLONG_MASK;
 167         unsigned long mask;
 168         unsigned long flags;
 169         int res;
 170
 171         a += nr >> SZLONG_LOG;
 172         mask = 1UL << bit;
 173         raw_local_irq_save(flags);
 174         res = (mask & *a) != 0;
 175         *a ^= mask;
 176         raw_local_irq_restore(flags);
 177         return res;
 178 }
 179 EXPORT_SYMBOL(__mips_test_and_change_bit);