release/src-rt-6.x/linux/linux-2.6/include/asm-parisc/bitops.h

   1 #ifndef _PARISC_BITOPS_H
   2 #define _PARISC_BITOPS_H
   3
   4 #include <linux/compiler.h>
   5 #include <asm/types.h>          /* for BITS_PER_LONG/SHIFT_PER_LONG */
   6 #include <asm/byteorder.h>
   7 #include <asm/atomic.h>
   8
   9 /*
  10  * HP-PARISC specific bit operations
  11  * for a detailed description of the functions please refer
  12  * to include/asm-i386/bitops.h or kerneldoc
  13  */
  14
  15 #define CHOP_SHIFTCOUNT(x) (((unsigned long) (x)) & (BITS_PER_LONG - 1))
  16
  17
  18 #define smp_mb__before_clear_bit()      smp_mb()
  19 #define smp_mb__after_clear_bit()       smp_mb()
  20
  21 /* See http://marc.theaimsgroup.com/?t=108826637900003 for discussion
  22  * on use of volatile and __*_bit() (set/clear/change):
  23  *      *_bit() want use of volatile.
  24  *      __*_bit() are "relaxed" and don't use spinlock or volatile.
  25  */
  26
  27 static __inline__ void set_bit(int nr, volatile unsigned long * addr)
  28 {
  29         unsigned long mask = 1UL << CHOP_SHIFTCOUNT(nr);
  30         unsigned long flags;
  31
  32         addr += (nr >> SHIFT_PER_LONG);
  33         _atomic_spin_lock_irqsave(addr, flags);
  34         *addr |= mask;
  35         _atomic_spin_unlock_irqrestore(addr, flags);
  36 }
  37
  38 static __inline__ void clear_bit(int nr, volatile unsigned long * addr)
  39 {
  40         unsigned long mask = ~(1UL << CHOP_SHIFTCOUNT(nr));
  41         unsigned long flags;
  42
  43         addr += (nr >> SHIFT_PER_LONG);
  44         _atomic_spin_lock_irqsave(addr, flags);
  45         *addr &= mask;
  46         _atomic_spin_unlock_irqrestore(addr, flags);
  47 }
  48
  49 static __inline__ void change_bit(int nr, volatile unsigned long * addr)
  50 {
  51         unsigned long mask = 1UL << CHOP_SHIFTCOUNT(nr);
  52         unsigned long flags;
  53
  54         addr += (nr >> SHIFT_PER_LONG);
  55         _atomic_spin_lock_irqsave(addr, flags);
  56         *addr ^= mask;
  57         _atomic_spin_unlock_irqrestore(addr, flags);
  58 }
  59
  60 static __inline__ int test_and_set_bit(int nr, volatile unsigned long * addr)
  61 {
  62         unsigned long mask = 1UL << CHOP_SHIFTCOUNT(nr);
  63         unsigned long old;
  64         unsigned long flags;
  65         int set;
  66
  67         addr += (nr >> SHIFT_PER_LONG);
  68         _atomic_spin_lock_irqsave(addr, flags);
  69         old = *addr;
  70         set = (old & mask) ? 1 : 0;
  71         if (!set)
  72                 *addr = old | mask;
  73         _atomic_spin_unlock_irqrestore(addr, flags);
  74
  75         return set;
  76 }
  77
  78 static __inline__ int test_and_clear_bit(int nr, volatile unsigned long * addr)
  79 {
  80         unsigned long mask = 1UL << CHOP_SHIFTCOUNT(nr);
  81         unsigned long old;
  82         unsigned long flags;
  83         int set;
  84
  85         addr += (nr >> SHIFT_PER_LONG);
  86         _atomic_spin_lock_irqsave(addr, flags);
  87         old = *addr;
  88         set = (old & mask) ? 1 : 0;
  89         if (set)
  90                 *addr = old & ~mask;
  91         _atomic_spin_unlock_irqrestore(addr, flags);
  92
  93         return set;
  94 }
  95
  96 static __inline__ int test_and_change_bit(int nr, volatile unsigned long * addr)
  97 {
  98         unsigned long mask = 1UL << CHOP_SHIFTCOUNT(nr);
  99         unsigned long oldbit;
 100         unsigned long flags;
 101
 102         addr += (nr >> SHIFT_PER_LONG);
 103         _atomic_spin_lock_irqsave(addr, flags);
 104         oldbit = *addr;
 105         *addr = oldbit ^ mask;
 106         _atomic_spin_unlock_irqrestore(addr, flags);
 107
 108         return (oldbit & mask) ? 1 : 0;
 109 }
 110
 111 #include <asm-generic/bitops/non-atomic.h>
 112
 113 #ifdef __KERNEL__
 114
 115 /**
 116  * __ffs - find first bit in word. returns 0 to "BITS_PER_LONG-1".
 117  * @word: The word to search
 118  *
 119  * __ffs() return is undefined if no bit is set.
 120  *
 121  * 32-bit fast __ffs by LaMont Jones "lamont At hp com".
 122  * 64-bit enhancement by Grant Grundler "grundler At parisc-linux org".
 123  * (with help from willy/jejb to get the semantics right)
 124  *
 125  * This algorithm avoids branches by making use of nullification.
 126  * One side effect of "extr" instructions is it sets PSW[N] bit.
 127  * How PSW[N] (nullify next insn) gets set is determined by the
 128  * "condition" field (eg "<>" or "TR" below) in the extr* insn.
 129  * Only the 1st and one of either the 2cd or 3rd insn will get executed.
 130  * Each set of 3 insn will get executed in 2 cycles on PA8x00 vs 16 or so
 131  * cycles for each mispredicted branch.
 132  */
 133
 134 static __inline__ unsigned long __ffs(unsigned long x)
 135 {
 136         unsigned long ret;
 137
 138         __asm__(
 139 #ifdef CONFIG_64BIT
 140                 " ldi       63,%1\n"
 141                 " extrd,u,*<>  %0,63,32,%%r0\n"
 142                 " extrd,u,*TR  %0,31,32,%0\n"   /* move top 32-bits down */
 143                 " addi    -32,%1,%1\n"
 144 #else
 145                 " ldi       31,%1\n"
 146 #endif
 147                 " extru,<>  %0,31,16,%%r0\n"
 148                 " extru,TR  %0,15,16,%0\n"      /* xxxx0000 -> 0000xxxx */
 149                 " addi    -16,%1,%1\n"
 150                 " extru,<>  %0,31,8,%%r0\n"
 151                 " extru,TR  %0,23,8,%0\n"       /* 0000xx00 -> 000000xx */
 152                 " addi    -8,%1,%1\n"
 153                 " extru,<>  %0,31,4,%%r0\n"
 154                 " extru,TR  %0,27,4,%0\n"       /* 000000x0 -> 0000000x */
 155                 " addi    -4,%1,%1\n"
 156                 " extru,<>  %0,31,2,%%r0\n"
 157                 " extru,TR  %0,29,2,%0\n"       /* 0000000y, 1100b -> 0011b */
 158                 " addi    -2,%1,%1\n"
 159                 " extru,=  %0,31,1,%%r0\n"      /* check last bit */
 160                 " addi    -1,%1,%1\n"
 161                         : "+r" (x), "=r" (ret) );
 162         return ret;
 163 }
 164
 165 #include <asm-generic/bitops/ffz.h>
 166
 167 /*
 168  * ffs: find first bit set. returns 1 to BITS_PER_LONG or 0 (if none set)
 169  * This is defined the same way as the libc and compiler builtin
 170  * ffs routines, therefore differs in spirit from the above ffz (man ffs).
 171  */
 172 static __inline__ int ffs(int x)
 173 {
 174         return x ? (__ffs((unsigned long)x) + 1) : 0;
 175 }
 176
 177 /*
 178  * fls: find last (most significant) bit set.
 179  * fls(0) = 0, fls(1) = 1, fls(0x80000000) = 32.
 180  */
 181
 182 static __inline__ int fls(int x)
 183 {
 184         int ret;
 185         if (!x)
 186                 return 0;
 187
 188         __asm__(
 189         "       ldi             1,%1\n"
 190         "       extru,<>        %0,15,16,%%r0\n"
 191         "       zdep,TR         %0,15,16,%0\n"          /* xxxx0000 */
 192         "       addi            16,%1,%1\n"
 193         "       extru,<>        %0,7,8,%%r0\n"
 194         "       zdep,TR         %0,23,24,%0\n"          /* xx000000 */
 195         "       addi            8,%1,%1\n"
 196         "       extru,<>        %0,3,4,%%r0\n"
 197         "       zdep,TR         %0,27,28,%0\n"          /* x0000000 */
 198         "       addi            4,%1,%1\n"
 199         "       extru,<>        %0,1,2,%%r0\n"
 200         "       zdep,TR         %0,29,30,%0\n"          /* y0000000 (y&3 = 0) */
 201         "       addi            2,%1,%1\n"
 202         "       extru,=         %0,0,1,%%r0\n"
 203         "       addi            1,%1,%1\n"              /* if y & 8, add 1 */
 204                 : "+r" (x), "=r" (ret) );
 205
 206         return ret;
 207 }
 208
 209 #include <asm-generic/bitops/fls64.h>
 210 #include <asm-generic/bitops/hweight.h>
 211 #include <asm-generic/bitops/sched.h>
 212
 213 #endif /* __KERNEL__ */
 214
 215 #include <asm-generic/bitops/find.h>
 216
 217 #ifdef __KERNEL__
 218
 219 #include <asm-generic/bitops/ext2-non-atomic.h>
 220
 221 /* '3' is bits per byte */
 222 #define LE_BYTE_ADDR ((sizeof(unsigned long) - 1) << 3)
 223
 224 #define ext2_set_bit_atomic(l,nr,addr) \
 225                 test_and_set_bit((nr)   ^ LE_BYTE_ADDR, (unsigned long *)addr)
 226 #define ext2_clear_bit_atomic(l,nr,addr) \
 227                 test_and_clear_bit( (nr) ^ LE_BYTE_ADDR, (unsigned long *)addr)
 228
 229 #endif  /* __KERNEL__ */
 230
 231 #include <asm-generic/bitops/minix-le.h>
 232
 233 #endif /* _PARISC_BITOPS_H */