arch/cris/include/asm/bitops.h

   1 /* asm/bitops.h for Linux/CRIS
   2  *
   3  * TODO: asm versions if speed is needed
   4  *
   5  * All bit operations return 0 if the bit was cleared before the
   6  * operation and != 0 if it was not.
   7  *
   8  * bit 0 is the LSB of addr; bit 32 is the LSB of (addr+1).
   9  */
  10
  11 #ifndef _CRIS_BITOPS_H
  12 #define _CRIS_BITOPS_H
  13
  14 /* Currently this is unsuitable for consumption outside the kernel.  */
  15 #ifdef __KERNEL__
  16
  17 #ifndef _LINUX_BITOPS_H
  18 #error only <linux/bitops.h> can be included directly
  19 #endif
  20
  21 #include <arch/bitops.h>
  22 #include <asm/system.h>
  23 #include <asm/atomic.h>
  24 #include <linux/compiler.h>
  25
  26 /*
  27  * set_bit - Atomically set a bit in memory
  28  * @nr: the bit to set
  29  * @addr: the address to start counting from
  30  *
  31  * This function is atomic and may not be reordered.  See __set_bit()
  32  * if you do not require the atomic guarantees.
  33  * Note that @nr may be almost arbitrarily large; this function is not
  34  * restricted to acting on a single-word quantity.
  35  */
  36
  37 #define set_bit(nr, addr)    (void)test_and_set_bit(nr, addr)
  38
  39 /*
  40  * clear_bit - Clears a bit in memory
  41  * @nr: Bit to clear
  42  * @addr: Address to start counting from
  43  *
  44  * clear_bit() is atomic and may not be reordered.  However, it does
  45  * not contain a memory barrier, so if it is used for locking purposes,
  46  * you should call smp_mb__before_clear_bit() and/or smp_mb__after_clear_bit()
  47  * in order to ensure changes are visible on other processors.
  48  */
  49
  50 #define clear_bit(nr, addr)  (void)test_and_clear_bit(nr, addr)
  51
  52 /*
  53  * change_bit - Toggle a bit in memory
  54  * @nr: Bit to change
  55  * @addr: Address to start counting from
  56  *
  57  * change_bit() is atomic and may not be reordered.
  58  * Note that @nr may be almost arbitrarily large; this function is not
  59  * restricted to acting on a single-word quantity.
  60  */
  61
  62 #define change_bit(nr, addr) (void)test_and_change_bit(nr, addr)
  63
  64 /**
  65  * test_and_set_bit - Set a bit and return its old value
  66  * @nr: Bit to set
  67  * @addr: Address to count from
  68  *
  69  * This operation is atomic and cannot be reordered.
  70  * It also implies a memory barrier.
  71  */
  72
  73 static inline int test_and_set_bit(int nr, volatile unsigned long *addr)
  74 {
  75         unsigned int mask, retval;
  76         unsigned long flags;
  77         unsigned int *adr = (unsigned int *)addr;
  78
  79         adr += nr >> 5;
  80         mask = 1 << (nr & 0x1f);
  81         cris_atomic_save(addr, flags);
  82         retval = (mask & *adr) != 0;
  83         *adr |= mask;
  84         cris_atomic_restore(addr, flags);
  85         return retval;
  86 }
  87
  88 /*
  89  * clear_bit() doesn't provide any barrier for the compiler.
  90  */
  91 #define smp_mb__before_clear_bit()      barrier()
  92 #define smp_mb__after_clear_bit()       barrier()
  93
  94 /**
  95  * test_and_clear_bit - Clear a bit and return its old value
  96  * @nr: Bit to clear
  97  * @addr: Address to count from
  98  *
  99  * This operation is atomic and cannot be reordered.
 100  * It also implies a memory barrier.
 101  */
 102
 103 static inline int test_and_clear_bit(int nr, volatile unsigned long *addr)
 104 {
 105         unsigned int mask, retval;
 106         unsigned long flags;
 107         unsigned int *adr = (unsigned int *)addr;
 108
 109         adr += nr >> 5;
 110         mask = 1 << (nr & 0x1f);
 111         cris_atomic_save(addr, flags);
 112         retval = (mask & *adr) != 0;
 113         *adr &= ~mask;
 114         cris_atomic_restore(addr, flags);
 115         return retval;
 116 }
 117
 118 /**
 119  * test_and_change_bit - Change a bit and return its old value
 120  * @nr: Bit to change
 121  * @addr: Address to count from
 122  *
 123  * This operation is atomic and cannot be reordered.
 124  * It also implies a memory barrier.
 125  */
 126
 127 static inline int test_and_change_bit(int nr, volatile unsigned long *addr)
 128 {
 129         unsigned int mask, retval;
 130         unsigned long flags;
 131         unsigned int *adr = (unsigned int *)addr;
 132         adr += nr >> 5;
 133         mask = 1 << (nr & 0x1f);
 134         cris_atomic_save(addr, flags);
 135         retval = (mask & *adr) != 0;
 136         *adr ^= mask;
 137         cris_atomic_restore(addr, flags);
 138         return retval;
 139 }
 140
 141 #include <asm-generic/bitops/non-atomic.h>
 142
 143 /*
 144  * Since we define it "external", it collides with the built-in
 145  * definition, which doesn't have the same semantics.  We don't want to
 146  * use -fno-builtin, so just hide the name ffs.
 147  */
 148 #define ffs kernel_ffs
 149
 150 #include <asm-generic/bitops/fls.h>
 151 #include <asm-generic/bitops/__fls.h>
 152 #include <asm-generic/bitops/fls64.h>
 153 #include <asm-generic/bitops/hweight.h>
 154 #include <asm-generic/bitops/find.h>
 155 #include <asm-generic/bitops/lock.h>
 156
 157 #include <asm-generic/bitops/le.h>
 158
 159 #define ext2_set_bit_atomic(l,n,a)   test_and_set_bit(n,a)
 160 #define ext2_clear_bit_atomic(l,n,a) test_and_clear_bit(n,a)
 161
 162 #include <asm-generic/bitops/sched.h>
 163
 164 #endif /* __KERNEL__ */
 165
 166 #endif /* _CRIS_BITOPS_H */