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 oldbit;
  64         unsigned long flags;
  65
  66         addr += (nr >> SHIFT_PER_LONG);
  67         _atomic_spin_lock_irqsave(addr, flags);
  68         oldbit = *addr;
  69         *addr = oldbit | mask;
  70         _atomic_spin_unlock_irqrestore(addr, flags);
  71
  72         return (oldbit & mask) ? 1 : 0;
  73 }
  74
  75 static __inline__ int test_and_clear_bit(int nr, volatile unsigned long * addr)
  76 {
  77         unsigned long mask = 1UL << CHOP_SHIFTCOUNT(nr);
  78         unsigned long oldbit;
  79         unsigned long flags;
  80
  81         addr += (nr >> SHIFT_PER_LONG);
  82         _atomic_spin_lock_irqsave(addr, flags);
  83         oldbit = *addr;
  84         *addr = oldbit & ~mask;
  85         _atomic_spin_unlock_irqrestore(addr, flags);
  86
  87         return (oldbit & mask) ? 1 : 0;
  88 }
  89
  90 static __inline__ int test_and_change_bit(int nr, volatile unsigned long * addr)
  91 {
  92         unsigned long mask = 1UL << CHOP_SHIFTCOUNT(nr);
  93         unsigned long oldbit;
  94         unsigned long flags;
  95
  96         addr += (nr >> SHIFT_PER_LONG);
  97         _atomic_spin_lock_irqsave(addr, flags);
  98         oldbit = *addr;
  99         *addr = oldbit ^ mask;
 100         _atomic_spin_unlock_irqrestore(addr, flags);
 101
 102         return (oldbit & mask) ? 1 : 0;
 103 }
 104
 105 #include <asm-generic/bitops/non-atomic.h>
 106
 107 #ifdef __KERNEL__
 108
 109 /**
 110  * __ffs - find first bit in word. returns 0 to "BITS_PER_LONG-1".
 111  * @word: The word to search
 112  *
 113  * __ffs() return is undefined if no bit is set.
 114  *
 115  * 32-bit fast __ffs by LaMont Jones "lamont At hp com".
 116  * 64-bit enhancement by Grant Grundler "grundler At parisc-linux org".
 117  * (with help from willy/jejb to get the semantics right)
 118  *
 119  * This algorithm avoids branches by making use of nullification.
 120  * One side effect of "extr" instructions is it sets PSW[N] bit.
 121  * How PSW[N] (nullify next insn) gets set is determined by the
 122  * "condition" field (eg "<>" or "TR" below) in the extr* insn.
 123  * Only the 1st and one of either the 2cd or 3rd insn will get executed.
 124  * Each set of 3 insn will get executed in 2 cycles on PA8x00 vs 16 or so
 125  * cycles for each mispredicted branch.
 126  */
 127
 128 static __inline__ unsigned long __ffs(unsigned long x)
 129 {
 130         unsigned long ret;
 131
 132         __asm__(
 133 #ifdef __LP64__
 134                 " ldi       63,%1\n"
 135                 " extrd,u,*<>  %0,63,32,%%r0\n"
 136                 " extrd,u,*TR  %0,31,32,%0\n"   /* move top 32-bits down */
 137                 " addi    -32,%1,%1\n"
 138 #else
 139                 " ldi       31,%1\n"
 140 #endif
 141                 " extru,<>  %0,31,16,%%r0\n"
 142                 " extru,TR  %0,15,16,%0\n"      /* xxxx0000 -> 0000xxxx */
 143                 " addi    -16,%1,%1\n"
 144                 " extru,<>  %0,31,8,%%r0\n"
 145                 " extru,TR  %0,23,8,%0\n"       /* 0000xx00 -> 000000xx */
 146                 " addi    -8,%1,%1\n"
 147                 " extru,<>  %0,31,4,%%r0\n"
 148                 " extru,TR  %0,27,4,%0\n"       /* 000000x0 -> 0000000x */
 149                 " addi    -4,%1,%1\n"
 150                 " extru,<>  %0,31,2,%%r0\n"
 151                 " extru,TR  %0,29,2,%0\n"       /* 0000000y, 1100b -> 0011b */
 152                 " addi    -2,%1,%1\n"
 153                 " extru,=  %0,31,1,%%r0\n"      /* check last bit */
 154                 " addi    -1,%1,%1\n"
 155                         : "+r" (x), "=r" (ret) );
 156         return ret;
 157 }
 158
 159 #include <asm-generic/bitops/ffz.h>
 160
 161 /*
 162  * ffs: find first bit set. returns 1 to BITS_PER_LONG or 0 (if none set)
 163  * This is defined the same way as the libc and compiler builtin
 164  * ffs routines, therefore differs in spirit from the above ffz (man ffs).
 165  */
 166 static __inline__ int ffs(int x)
 167 {
 168         return x ? (__ffs((unsigned long)x) + 1) : 0;
 169 }
 170
 171 /*
 172  * fls: find last (most significant) bit set.
 173  * fls(0) = 0, fls(1) = 1, fls(0x80000000) = 32.
 174  */
 175
 176 static __inline__ int fls(int x)
 177 {
 178         int ret;
 179         if (!x)
 180                 return 0;
 181
 182         __asm__(
 183         "       ldi             1,%1\n"
 184         "       extru,<>        %0,15,16,%%r0\n"
 185         "       zdep,TR         %0,15,16,%0\n"          /* xxxx0000 */
 186         "       addi            16,%1,%1\n"
 187         "       extru,<>        %0,7,8,%%r0\n"
 188         "       zdep,TR         %0,23,24,%0\n"          /* xx000000 */
 189         "       addi            8,%1,%1\n"
 190         "       extru,<>        %0,3,4,%%r0\n"
 191         "       zdep,TR         %0,27,28,%0\n"          /* x0000000 */
 192         "       addi            4,%1,%1\n"
 193         "       extru,<>        %0,1,2,%%r0\n"
 194         "       zdep,TR         %0,29,30,%0\n"          /* y0000000 (y&3 = 0) */
 195         "       addi            2,%1,%1\n"
 196         "       extru,=         %0,0,1,%%r0\n"
 197         "       addi            1,%1,%1\n"              /* if y & 8, add 1 */
 198                 : "+r" (x), "=r" (ret) );
 199
 200         return ret;
 201 }
 202
 203 #include <asm-generic/bitops/fls64.h>
 204 #include <asm-generic/bitops/hweight.h>
 205 #include <asm-generic/bitops/sched.h>
 206
 207 #endif /* __KERNEL__ */
 208
 209 #include <asm-generic/bitops/find.h>
 210
 211 #ifdef __KERNEL__
 212
 213 #include <asm-generic/bitops/ext2-non-atomic.h>
 214
 215 /* '3' is bits per byte */
 216 #define LE_BYTE_ADDR ((sizeof(unsigned long) - 1) << 3)
 217
 218 #define ext2_set_bit_atomic(l,nr,addr) \
 219                 test_and_set_bit((nr)   ^ LE_BYTE_ADDR, (unsigned long *)addr)
 220 #define ext2_clear_bit_atomic(l,nr,addr) \
 221                 test_and_clear_bit( (nr) ^ LE_BYTE_ADDR, (unsigned long *)addr)
 222
 223 #endif  /* __KERNEL__ */
 224
 225 #include <asm-generic/bitops/minix-le.h>
 226
 227 #endif /* _PARISC_BITOPS_H */