include/asm-sh/bitops.h

   1 #ifndef __ASM_SH_BITOPS_H
   2 #define __ASM_SH_BITOPS_H
   3
   4 #ifdef __KERNEL__
   5 #include <asm/irqflags.h>
   6 /* For __swab32 */
   7 #include <asm/byteorder.h>
   8
   9 static inline void set_bit(int nr, volatile void * addr)
  10 {
  11         int     mask;
  12         volatile unsigned int *a = addr;
  13         unsigned long flags;
  14
  15         a += nr >> 5;
  16         mask = 1 << (nr & 0x1f);
  17         local_irq_save(flags);
  18         *a |= mask;
  19         local_irq_restore(flags);
  20 }
  21
  22 /*
  23  * clear_bit() doesn't provide any barrier for the compiler.
  24  */
  25 #define smp_mb__before_clear_bit()      barrier()
  26 #define smp_mb__after_clear_bit()       barrier()
  27 static inline void clear_bit(int nr, volatile void * addr)
  28 {
  29         int     mask;
  30         volatile unsigned int *a = addr;
  31         unsigned long flags;
  32
  33         a += nr >> 5;
  34         mask = 1 << (nr & 0x1f);
  35         local_irq_save(flags);
  36         *a &= ~mask;
  37         local_irq_restore(flags);
  38 }
  39
  40 static inline void change_bit(int nr, volatile void * addr)
  41 {
  42         int     mask;
  43         volatile unsigned int *a = addr;
  44         unsigned long flags;
  45
  46         a += nr >> 5;
  47         mask = 1 << (nr & 0x1f);
  48         local_irq_save(flags);
  49         *a ^= mask;
  50         local_irq_restore(flags);
  51 }
  52
  53 static inline int test_and_set_bit(int nr, volatile void * addr)
  54 {
  55         int     mask, retval;
  56         volatile unsigned int *a = addr;
  57         unsigned long flags;
  58
  59         a += nr >> 5;
  60         mask = 1 << (nr & 0x1f);
  61         local_irq_save(flags);
  62         retval = (mask & *a) != 0;
  63         *a |= mask;
  64         local_irq_restore(flags);
  65
  66         return retval;
  67 }
  68
  69 static inline int test_and_clear_bit(int nr, volatile void * addr)
  70 {
  71         int     mask, retval;
  72         volatile unsigned int *a = addr;
  73         unsigned long flags;
  74
  75         a += nr >> 5;
  76         mask = 1 << (nr & 0x1f);
  77         local_irq_save(flags);
  78         retval = (mask & *a) != 0;
  79         *a &= ~mask;
  80         local_irq_restore(flags);
  81
  82         return retval;
  83 }
  84
  85 static inline int test_and_change_bit(int nr, volatile void * addr)
  86 {
  87         int     mask, retval;
  88         volatile unsigned int *a = addr;
  89         unsigned long flags;
  90
  91         a += nr >> 5;
  92         mask = 1 << (nr & 0x1f);
  93         local_irq_save(flags);
  94         retval = (mask & *a) != 0;
  95         *a ^= mask;
  96         local_irq_restore(flags);
  97
  98         return retval;
  99 }
 100
 101 static inline unsigned long ffz(unsigned long word)
 102 {
 103         unsigned long result;
 104
 105         __asm__("1:\n\t"
 106                 "shlr   %1\n\t"
 107                 "bt/s   1b\n\t"
 108                 " add   #1, %0"
 109                 : "=r" (result), "=r" (word)
 110                 : "0" (~0L), "1" (word)
 111                 : "t");
 112         return result;
 113 }
 114
 115 /**
 116  * ffs - find first bit in word.
 117  * @word: The word to search
 118  *
 119  * Undefined if no bit exists, so code should check against 0 first.
 120  */
 121 static inline int ffs (int x)
 122 {
 123         int r = 1;
 124
 125         if (!x)
 126                 return 0;
 127         if (!(x & 0xffff)) {
 128                 x >>= 16;
 129                 r += 16;
 130         }
 131         if (!(x & 0xff)) {
 132                 x >>= 8;
 133                 r += 8;
 134         }
 135         if (!(x & 0xf)) {
 136                 x >>= 4;
 137                 r += 4;
 138         }
 139         if (!(x & 3)) {
 140                 x >>= 2;
 141                 r += 2;
 142         }
 143         if (!(x & 1)) {
 144                 x >>= 1;
 145                 r += 1;
 146         }
 147         return r;
 148 }
 149 #endif /* __KERNEL__ */
 150
 151 #endif /* __ASM_SH_BITOPS_H */