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/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);