include/asm-cris/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 <asm/arch/bitops.h>
  22 #include <asm/system.h>
  23 #include <asm/atomic.h>
  24 #include <linux/compiler.h>
  25
  26 /*
  27  * Some hacks to defeat gcc over-optimizations..
  28  */
  29 struct __dummy { unsigned long a[100]; };
  30 #define ADDR (*(struct __dummy *) addr)
  31 #define CONST_ADDR (*(const struct __dummy *) addr)
  32
  33 /*
  34  * set_bit - Atomically set a bit in memory
  35  * @nr: the bit to set
  36  * @addr: the address to start counting from
  37  *
  38  * This function is atomic and may not be reordered.  See __set_bit()
  39  * if you do not require the atomic guarantees.
  40  * Note that @nr may be almost arbitrarily large; this function is not
  41  * restricted to acting on a single-word quantity.
  42  */
  43
  44 #define set_bit(nr, addr)    (void)test_and_set_bit(nr, addr)
  45
  46 /*
  47  * clear_bit - Clears a bit in memory
  48  * @nr: Bit to clear
  49  * @addr: Address to start counting from
  50  *
  51  * clear_bit() is atomic and may not be reordered.  However, it does
  52  * not contain a memory barrier, so if it is used for locking purposes,
  53  * you should call smp_mb__before_clear_bit() and/or smp_mb__after_clear_bit()
  54  * in order to ensure changes are visible on other processors.
  55  */
  56
  57 #define clear_bit(nr, addr)  (void)test_and_clear_bit(nr, addr)
  58
  59 /*
  60  * change_bit - Toggle a bit in memory
  61  * @nr: Bit to change
  62  * @addr: Address to start counting from
  63  *
  64  * change_bit() is atomic and may not be reordered.
  65  * Note that @nr may be almost arbitrarily large; this function is not
  66  * restricted to acting on a single-word quantity.
  67  */
  68
  69 #define change_bit(nr, addr) (void)test_and_change_bit(nr, addr)
  70
  71 /**
  72  * test_and_set_bit - Set a bit and return its old value
  73  * @nr: Bit to set
  74  * @addr: Address to count from
  75  *
  76  * This operation is atomic and cannot be reordered.
  77  * It also implies a memory barrier.
  78  */
  79
  80 static inline int test_and_set_bit(int nr, volatile unsigned long *addr)
  81 {
  82         unsigned int mask, retval;
  83         unsigned long flags;
  84         unsigned int *adr = (unsigned int *)addr;
  85
  86         adr += nr >> 5;
  87         mask = 1 << (nr & 0x1f);
  88         cris_atomic_save(addr, flags);
  89         retval = (mask & *adr) != 0;
  90         *adr |= mask;
  91         cris_atomic_restore(addr, flags);
  92         return retval;
  93 }
  94
  95 /*
  96  * clear_bit() doesn't provide any barrier for the compiler.
  97  */
  98 #define smp_mb__before_clear_bit()      barrier()
  99 #define smp_mb__after_clear_bit()       barrier()
 100
 101 /**
 102  * test_and_clear_bit - Clear a bit and return its old value
 103  * @nr: Bit to clear
 104  * @addr: Address to count from
 105  *
 106  * This operation is atomic and cannot be reordered.
 107  * It also implies a memory barrier.
 108  */
 109
 110 static inline int test_and_clear_bit(int nr, volatile unsigned long *addr)
 111 {
 112         unsigned int mask, retval;
 113         unsigned long flags;
 114         unsigned int *adr = (unsigned int *)addr;
 115
 116         adr += nr >> 5;
 117         mask = 1 << (nr & 0x1f);
 118         cris_atomic_save(addr, flags);
 119         retval = (mask & *adr) != 0;
 120         *adr &= ~mask;
 121         cris_atomic_restore(addr, flags);
 122         return retval;
 123 }
 124
 125 /**
 126  * test_and_change_bit - Change a bit and return its old value
 127  * @nr: Bit to change
 128  * @addr: Address to count from
 129  *
 130  * This operation is atomic and cannot be reordered.
 131  * It also implies a memory barrier.
 132  */
 133
 134 static inline int test_and_change_bit(int nr, volatile unsigned long *addr)
 135 {
 136         unsigned int mask, retval;
 137         unsigned long flags;
 138         unsigned int *adr = (unsigned int *)addr;
 139         adr += nr >> 5;
 140         mask = 1 << (nr & 0x1f);
 141         cris_atomic_save(addr, flags);
 142         retval = (mask & *adr) != 0;
 143         *adr ^= mask;
 144         cris_atomic_restore(addr, flags);
 145         return retval;
 146 }
 147
 148 #include <asm-generic/bitops/non-atomic.h>
 149
 150 /*
 151  * Since we define it "external", it collides with the built-in
 152  * definition, which doesn't have the same semantics.  We don't want to
 153  * use -fno-builtin, so just hide the name ffs.
 154  */
 155 #define ffs kernel_ffs
 156
 157 #include <asm-generic/bitops/fls.h>
 158 #include <asm-generic/bitops/fls64.h>
 159 #include <asm-generic/bitops/hweight.h>
 160 #include <asm-generic/bitops/find.h>
 161 #include <asm-generic/bitops/lock.h>
 162
 163 #include <asm-generic/bitops/ext2-non-atomic.h>
 164
 165 #define ext2_set_bit_atomic(l,n,a)   test_and_set_bit(n,a)
 166 #define ext2_clear_bit_atomic(l,n,a) test_and_clear_bit(n,a)
 167
 168 #include <asm-generic/bitops/minix.h>
 169 #include <asm-generic/bitops/sched.h>
 170
 171 #endif /* __KERNEL__ */
 172
 173 #endif /* _CRIS_BITOPS_H */